300 results on '"Taib N"'
Search Results
102. Effects of devolatilization on the hydrogen isotopic composition of pelitic rocks in the contact aureole of the Duluth Complex, northeastern Minnesota, U.S.A.
- Author
-
Ripley, E. M., Butler, B. K., and Taib, N. I.
- Published
- 1992
- Full Text
- View/download PDF
103. The Will Rogers phenomenon in the staging of breast cancer - Does it matter?
- Author
-
Tan, G. H., Bhoo-Pathy, N., Taib, N. A., See, M. H., Jamaris, S., and Yip, C. H.
- Subjects
- *
BREAST cancer diagnosis , *CANCER invasiveness , *DISEASES in women , *MEDICAL errors , *EPIDEMIOLOGY - Abstract
Introduction: Changes in the American Joint Commission on Cancer staging for breast cancer occurred when the 5th Edition was updated to the 6th Edition. Objective: To investigate how these changes affected stage and survival. Methods: 3127 cases of breast cancer were restaged. Results: Late stages increased from 27.7% to 38.1%. The five-year survival improved in Stage 2 (82.9-86.1%) and Stage 3 (50.6-59%). Discussion: Stage shift leads to an erroneous impression that women are presenting with later stages and stage-specific survival is improving. Conclusion: Standardizing cancer staging is important when reporting stage and survival in different time periods. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
104. 422ONeeds of cancer patients in an Asian setting.
- Author
-
Bhoo-Pathy, N, Kong, Y C, Bustamam, R S, Bin, A Matin Mellor, Zaharah, H, Taib, N A, Ho, G F, and Yip, C H
- Subjects
- *
CANCER patients , *FINANCIAL aid , *SUPPORT groups , *JOB security , *PSYCHOLOGICAL distress , *VOICE disorders - Abstract
Background The ASEAN Costs in Oncology (ACTION) Study had previously reported high levels of psychological distress among cancer survivors in the region. We aimed to gain an in-depth understanding of the (unmet) needs in Asian patients living with cancer in a middle-income setting. Methods Twenty focus group discussions were conducted among patients with breast, cervical, prostate or colorectal cancer (N = 102) at five tertiary Malaysian hospitals (public, academic, private). Thematic analysis was performed. Results Seven themes were identified. (1) Information; participants emphasized the need for physicians to provide detailed information on latest treatment options. Besides medical advice, informational needs on diet, and traditional and complementary medicine remained unmet."(2) Psychosocial; "coping with cancer diagnosis" and "fear of recurrence" were major issues. The need for "support groups" as a source of informational and psychological support was raised. It was also stressed that increased "public awareness" was needed to circumvent the stigma against cancer survivors. (3) Physical; patients stressed on concerns regarding "side effects of treatment", including "fertility", "sexuality" and "sexual function". (4) Practical support; major unmet needs in "transportation and parking" and "comfortable facilities" in hospitals were reported. (5) Financial; The burden of "out-of-pocket" expenses, "paying first then claim" and the costs of "essential items" e.g. breast prosthesis, colostomy bags were highlighted. (6) Systemic; Issues with "accessibility and eligibility of financial aid" were frustrating to needy patients. The need for an "integrated care system" where different departments work together to avoid repeated tests, and consolidate hospital appointments into the same day was repeatedly raised. (7) Employment; Patients needed "job security" and "cancer leave". Lack of work-related flexibility, and discrimination at workplace were voiced out. Conclusions There seems to be an overarching theme of limited patient-centered healthcare during the survivorship period in Asian settings. These findings underscore the need for holistic cancer survivorship services that address wider aspects of wellbeing including the urgent need for patient navigation programs. Legal entity responsible for the study The authors. Funding Pharmaceutical Association of Malaysia. Disclosure N. Bhoo-Pathy: Research grant / Funding (institution): Pharmaceutical Association of Malaysia. All other authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
105. OP0007 What if all cancer patients in Malaysia had access to the best available care: How many deaths are avoidable?
- Author
-
Ho, G. F., Tho, L. M., Mastura, M. Y., Taib, N. A., Yip, C. H., Aina, E. N., Lim, G. C. C., Kaur, R. P., Tharan, S., Singh, M., Dass, A. S., Tan, H. C., Hoo, L. P., and Lim, T. O.
- Subjects
- *
CONFERENCES & conventions , *HEALTH services accessibility , *SURVIVAL , *TUMORS , *COST analysis - Abstract
Background: Malaysia spends 4% of its gross domestic product (GDP) on health care despite its wealth (GDP per head in 2011 was PPP-US$15,589). There are no data for Malaysia's spending on cancer care, only on anti-cancer medicines, which amounted to US$ 1900 per cancer patient (IMS 2012). By contrast, Australia spent US$ 4800 per patient. This could be one factor affecting cancer mortality; GLOBOCAN12 reported a mortality-to-incidence ratio of 60% for Malaysia (49% for breast cancer [BC]), whereas the corresponding ratio for Australia was 30% (16% for BC). This underinvestment in cancer care in Malaysia could be due to various reasons. There is room to improve our understanding and appreciation of the economic and health benefits of cancer care. Evidence of the potential effect of adequate cancer services on the health of the nation will help in the revision of priorities. To make the health benefits of cancer care more tangible, we aimed to estimate the number of deaths due to BC that would be avoidable if all Malaysian patients had access to the care provided by leading centres in Malaysia. Methods: The number of avoidable deaths is the difference between the number of deaths estimated by GLOBOCAN12 and the expected number of deaths if all BC patients had experienced the age-ethnic-stage specific survival outcomes observed in leading cancer treatment centres in Malaysia. Data for age-ethnic-stage composition of the general BC population were from local cancer registries and public hospitals providing safety net services. Findings: Of the 2572 deaths due to BC reported by GLOBOCAN12, 1299 (50%) were avoidable. Of these avoidable deaths, 647 (50%) were attributable to late-stage presentation and 652 (50%) were due to lack of access to optimum treatment. Interpretation: Avoidable premature deaths were high in Malaysia, consistent with its high cancer mortality rate. Avoidable deaths were equally attributable to lack of early detection and access to treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
106. Terrabacteria: redefining bacterial envelope diversity, biogenesis and evolution.
- Author
-
Beaud Benyahia B, Taib N, Beloin C, and Gribaldo S
- Abstract
The bacterial envelope is one of the oldest and most essential cellular components and has been traditionally divided into Gram-positive (monoderm) and Gram-negative (diderm). Recent landmark studies have challenged a major paradigm in microbiology by inferring that the last bacterial common ancestor had a diderm envelope and that the outer membrane (OM) was lost repeatedly in evolution to give rise to monoderms. Intriguingly, OM losses appear to have occurred exclusively in the Terrabacteria, one of the two major clades of bacteria. In this Review, we present current knowledge about the Terrabacteria. We describe their diversity and phylogeny and then highlight the vast phenotypic diversity of the Terrabacteria cell envelopes, which display large deviations from the textbook examples of diderms and monoderms, challenging the classical Gram-positive-Gram-negative divide. We highlight the striking differences in the systems involved in OM biogenesis in Terrabacteria with respect to the classical diderm experimental models and how they provide novel insights into the diversity and biogenesis of the bacterial cell envelope. We also discuss the potential evolutionary steps that might have led to the multiple losses of the OM and speculate on how the very first OM might have emerged before the last bacterial common ancestor., (© 2024. Springer Nature Limited.)
- Published
- 2024
- Full Text
- View/download PDF
107. Borg extrachromosomal elements of methane-oxidizing archaea have conserved and expressed genetic repertoires.
- Author
-
Schoelmerich MC, Ly L, West-Roberts J, Shi LD, Shen C, Malvankar NS, Taib N, Gribaldo S, Woodcroft BJ, Schadt CW, Al-Shayeb B, Dai X, Mozsary C, Hickey S, He C, Beaulaurier J, Juul S, Sachdeva R, and Banfield JF
- Subjects
- Oxidation-Reduction, Archaea genetics, Archaea metabolism, Nanopore Sequencing methods, DNA Methylation, Soil Microbiology, Genome, Archaeal, Methane metabolism, Phylogeny
- Abstract
Borgs are huge extrachromosomal elements (ECE) of anaerobic methane-consuming "Candidatus Methanoperedens" archaea. Here, we used nanopore sequencing to validate published complete genomes curated from short reads and to reconstruct new genomes. 13 complete and four near-complete linear genomes share 40 genes that define a largely syntenous genome backbone. We use these conserved genes to identify new Borgs from peatland soil and to delineate Borg phylogeny, revealing two major clades. Remarkably, Borg genes encoding nanowire-like electron-transferring cytochromes and cell surface proteins are more highly expressed than those of host Methanoperedens, indicating that Borgs augment the Methanoperedens activity in situ. We reconstructed the first complete 4.00 Mbp genome for a Methanoperedens that is inferred to be a Borg host and predicted its methylation motifs, which differ from pervasive TC and CC methylation motifs of the Borgs. Thus, methylation may enable Methanoperedens to distinguish their genomes from those of Borgs. Very high Borg to Methanoperedens ratios and structural predictions suggest that Borgs may be capable of encapsulation. The findings clearly define Borgs as a distinct class of ECE with shared genomic signatures, establish their diversification from a common ancestor with genetic inheritance, and raise the possibility of periodic existence outside of host cells., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
108. Correction: Tear Samples for Protein Extraction: Comparative Analysis of Schirmer's Test Strip and Microcapillary Tube Methods.
- Author
-
Tham ML, Mahmud A, Abdullah M, Md Saleh R, Mohammad Razali A, Cheah YK, Mohd Taib N, Ho KL, Mahmud M, and Mohd Isa M
- Abstract
[This corrects the article DOI: 10.7759/cureus.50972.]., Competing Interests: No competing interests declared., (Copyright © 2024, Tham et al.)
- Published
- 2024
- Full Text
- View/download PDF
109. New coordinated drive mode switching strategy for distributed drive electric vehicles with energy storage system.
- Author
-
Oubelaid A, Kakouche K, Belkhier Y, Khosravi N, Taib N, Rekioua T, Bajaj M, Rekioua D, and Tuka MB
- Abstract
High performance and comfort are key features recommended in hybrid electric vehicle (HEV) design. In this paper, a new coordination strategy is proposed to solve the issue of undesired torque jerks and large power ripples noticed respectively during drive mode commutations and power sources switching. The proposed coordinated switching strategy uses stair-based transition function to perform drive mode commutations and power source switching's within defined transition periods fitting the transient dynamics of power sources and traction machines. The proposed technique is applied on a battery/ supercapacitor electric vehicle whose traction is ensured by two permanent magnet synchronous machines controlled using direct torque control and linked to HEV front and rear wheels. Simulation results highlight that the proposed coordinated switching strategy has a noteworthy positive impact on enhancing HEV transient performance as DC bus fluctuations were reduced to a narrow band of 6 V and transient torque ripples were almost suppressed., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
110. Proteins containing photosynthetic reaction centre domains modulate FtsZ-based archaeal cell division.
- Author
-
Nußbaum P, Kureisaite-Ciziene D, Bellini D, van der Does C, Kojic M, Taib N, Yeates A, Tourte M, Gribaldo S, Loose M, Löwe J, and Albers SV
- Subjects
- Cell Division, Cytoskeleton, Microscopy, Fluorescence, Haloferax volcanii genetics, Photosynthetic Reaction Center Complex Proteins
- Abstract
Cell division in all domains of life requires the orchestration of many proteins, but in Archaea most of the machinery remains poorly characterized. Here we investigate the FtsZ-based cell division mechanism in Haloferax volcanii and find proteins containing photosynthetic reaction centre (PRC) barrel domains that play an essential role in archaeal cell division. We rename these proteins cell division protein B 1 (CdpB1) and CdpB2. Depletions and deletions in their respective genes cause severe cell division defects, generating drastically enlarged cells. Fluorescence microscopy of tagged FtsZ1, FtsZ2 and SepF in CdpB1 and CdpB2 mutant strains revealed an unusually disordered divisome that is not organized into a distinct ring-like structure. Biochemical analysis shows that SepF forms a tripartite complex with CdpB1/2 and crystal structures suggest that these two proteins might form filaments, possibly aligning SepF and the FtsZ2 ring during cell division. Overall our results indicate that PRC-domain proteins play essential roles in FtsZ-based cell division in Archaea., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2024
- Full Text
- View/download PDF
111. Chronic inflammation and cancer; the two sides of a coin.
- Author
-
Fernandes Q, Inchakalody VP, Bedhiafi T, Mestiri S, Taib N, Uddin S, Merhi M, and Dermime S
- Subjects
- Humans, Inflammation therapy, Cell Transformation, Neoplastic pathology, Neoplasms therapy
- Abstract
The correlation between chronic inflammation and cancer was initially identified in the 19th century. Biomolecules like interleukins, chemokines, tumor necrosis factors, growth factors, and adhesion molecules, which regulate inflammation, are recognized contributors to neoplastic transformation through various mechanisms, including oncogenic mutations, resistance to apoptosis, and adaptive responses like angiogenesis. This review aims to establish connections between the intricate and complex mechanisms of chronic inflammation and cancer. We illuminate implicit signaling mechanisms that drive the association between chronic inflammation and the initiation/progression of cancer, exploring potential impacts on other diseases. Additionally, we discuss the modalities of currently available therapeutic options for chronic inflammation and cancer, emphasizing the dual nature of such therapies. A thorough understanding of the molecular basis of chronic inflammation is crucial for developing novel approaches in the prevention and treatment of cancer., Competing Interests: Declaration of competing interest The authors declare that this work was conducted in the absence of any financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
112. 68 Ga-prostate specific membrane antigen-11 PET/CT versus multiparametric MRI in the detection of primary prostate cancer: A systematic review and head-to-head comparative meta-analysis.
- Author
-
Ren X, Nur Salihin Yusoff M, Hartini Mohd Taib N, Zhang L, and Wang K
- Subjects
- Male, Humans, Positron Emission Tomography Computed Tomography methods, Gallium Radioisotopes, Prostate, Multiparametric Magnetic Resonance Imaging methods, Prostatic Neoplasms diagnostic imaging
- Abstract
Purpose: The goal of this study was to evaluate the effectiveness of two diagnostic methods,
68 Ga-PSMA-11 PET/CT and mpMRI, in detecting primary prostate cancer without limitations on the Gleason score., Methods: We conducted a comprehensive literature review, searching databases such as PubMed, Embase, and Web of Science until June 2023. Our objective was to identify studies that compared the efficacy of68 Ga-PSMA-11 PET/CT and mpMRI in detecting primary prostate cancer. To determine heterogeneity, the I2 statistic was used. Meta-regression analysis and leave-one-out sensitivity analysis were conducted to identify potential sources of heterogeneity., Results: Initially, 1286 publications were found, but after careful evaluation, only 16 studies involving 1227 patients were analyzed thoroughly. The results showed that the68 Ga-PSMA-11 PET/CT method had a pooled sensitivity and specificity of 0.87 (95 % CI: 0.80-0.92) and 0.80 (95 % CI: 0.69-0.89), respectively, for diagnosing prostatic cancer. Similarly, the values for mpMRI were determined as 0.84 (95 % CI: 0.75-0.92) and 0.74 (95 % CI: 0.61-0.86), respectively. There were no significant differences in diagnostic effectiveness observed when comparing two primary prostate cancer methodologies (pooled sensitivity P = 0.62, pooled specificity P = 0.50). Despite this, the funnel plots showed symmetry and the Egger test results (P values > 0.05) suggested there was no publication bias., Conclusions: After an extensive meta-analysis, it was found that both68 Ga-PSMA-11 PET/CT and mpMRI demonstrate similar diagnostic effectiveness in detecting primary prostate cancer. Future larger prospective studies are warranted to investigate this issue further., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
113. Tear Samples for Protein Extraction: Comparative Analysis of Schirmer's Test Strip and Microcapillary Tube Methods.
- Author
-
Tham ML, Mahmud A, Abdullah M, Md Saleh R, Mohammad Razali A, Cheah YK, Mohd Taib N, Ho KL, Mahmud M, and Mohd Isa M
- Abstract
Introduction: Tear sampling is an attractive option for collecting biological samples in ophthalmology clinics, as it offers a non-invasive alternative to other invasive techniques. However, there are many tear sampling methods still in consideration. This study explores the suitability of Schirmer's test strip and microcapillary tube as reliable and satisfactory methods for tear sampling., Methods: Tear samples were collected from eight healthy volunteers using the standard Schirmer's test strip method with or without anesthesia and microcapillary tubes. The total tear protein concentrations were analyzed via spectrophotometry and bicinchoninic acid (BCA) protein assay. The protein profile was determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal wetting length of Schirmer's strip and suitable buffer solutions were compared. Discomfort levels reported by participants and the ease of execution for ophthalmologists were also evaluated., Results: Tear samples exhibited typical protein profiles as shown by SDS-PAGE. The mean total protein obtained from an optimum wetting length of 20 mm using Schirmer's strip without anesthesia in phosphate-buffered saline (PBS) yielded substantial quantities of protein as measured by nanophotometer (220.20 ± 67.43 µg) and the BCA protein assay (210.34 ± 59.46 µg). This method collected a significantly higher quantity of protein compared to the microcapillary tube method (p=0.004) which was much more difficult to standardize. The clinician found it harder to utilize microcapillary tubes, while participants experienced higher insecurity and less discomfort with the microcapillary tube method. PBS used during the tear protein extraction process eluted higher tear protein concentration than ammonium bicarbonate, although the difference was not statistically significant. Using anaesthesia did not ease the sampling procedure substantially and protein quantity was maintained., Conclusion: Good quality and quantity of protein from tear samples were extracted with the optimized procedure. Schirmer's strip test in the absence of local anesthesia provided a standard, convenient, and non-invasive method for tear collection., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Tham et al.)
- Published
- 2023
- Full Text
- View/download PDF
114. Diversification of division mechanisms in endospore-forming bacteria revealed by analyses of peptidoglycan synthesis in Clostridioides difficile.
- Author
-
Shrestha S, Taib N, Gribaldo S, and Shen A
- Subjects
- Bacterial Proteins genetics, Bacterial Proteins metabolism, Peptidoglycan metabolism, Membrane Proteins metabolism, Clostridioides difficile genetics, Clostridioides difficile metabolism, Endospore-Forming Bacteria metabolism
- Abstract
The bacterial enzymes FtsW and FtsI, encoded in the highly conserved dcw gene cluster, are considered to be universally essential for the synthesis of septal peptidoglycan (PG) during cell division. Here, we show that the pathogen Clostridioides difficile lacks a canonical FtsW/FtsI pair, and its dcw-encoded PG synthases have undergone a specialization to fulfill sporulation-specific roles, including synthesizing septal PG during the sporulation-specific mode of cell division. Although these enzymes are directly regulated by canonical divisome components during this process, dcw-encoded PG synthases and their divisome regulators are dispensable for cell division during normal growth. Instead, C. difficile uses a bifunctional class A penicillin-binding protein as the core divisome PG synthase, revealing a previously unreported role for this class of enzymes. Our findings support that the emergence of endosporulation in the Firmicutes phylum facilitated the functional repurposing of cell division factors. Moreover, they indicate that C. difficile, and likely other clostridia, assemble a distinct divisome that therefore may represent a unique target for therapeutic interventions., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
115. A multicentre study to determine the in vitro efficacy of flomoxef against extended-spectrum beta-lactamase producing Escherichia coli in Malaysia.
- Author
-
Yap PSX, Chong CW, Ponnampalavanar S, Ramli R, Harun A, Tengku Jamaluddin TZM, Ahmed Khan A, Ngoi ST, Lee YQ, Lau MY, Tan SC, Kong ZX, Woon JJ, Mak ST, Abdul Jabar K, Karunakaran R, Ismail Z, Salleh SA, Md Noor SS, Masri SN, Mohd Taib N, Jasni AS, Tee LH, Leong KC, Lim VKE, Abu Bakar S, and Teh CSJ
- Subjects
- Humans, Anti-Bacterial Agents pharmacology, beta-Lactamases genetics, Carbapenems pharmacology, Escherichia coli genetics, Malaysia epidemiology, Escherichia coli Infections drug therapy
- Abstract
Background: The high burden of extended-spectrum beta-lactamase-producing (ESBL)-producing Enterobacterales worldwide, especially in the densely populated South East Asia poses a significant threat to the global transmission of antibiotic resistance. Molecular surveillance of ESBL-producing pathogens in this region is vital for understanding the local epidemiology, informing treatment choices, and addressing the regional and global implications of antibiotic resistance., Methods: Therefore, an inventory surveillance of the ESBL- Escherichia coli (ESBL-EC) isolates responsible for infections in Malaysian hospitals was conducted. Additionally, the in vitro efficacy of flomoxef and other established antibiotics against ESBL-EC was evaluated., Results: A total of 127 non-repetitive ESBL-EC strains isolated from clinical samples were collected during a multicentre study performed in five representative Malaysian hospitals. Of all the isolates, 33.9% were isolated from surgical site infections and 85.8% were hospital-acquired infections. High rates of resistance to cefotaxime (100%), cefepime (100%), aztreonam (100%) and trimethoprim-sulfamethoxazole (100%) were observed based on the broth microdilution test. Carbapenems remained the most effective antibiotics against the ESBL-EC, followed by flomoxef. Antibiotic resistance genes were identified by PCR. The bla
CTX-M-1 was the most prevalent ESBL gene, with 28 isolates (22%) harbouring blaCTX-M-1 only, 27 isolates (21.3%) co-harbouring blaCTX-M-1 and blaTEM , and ten isolates (7.9%) co-harbouring blaCTX-M-1, blaTEM and blaSHV . A generalised linear model showed significant antibacterial activity of imipenem against different types of infection. Besides carbapenems, this study also demonstrated a satisfactory antibacterial activity of flomoxef (81.9%) on ESBL-EC, regardless of the types of ESBL genes., Competing Interests: Cindy Shuan Ju Teh is an Academic Editor for PeerJ. Loong Hua Tee and Kin Chong Leong were employed by Shionogi Singapore Pte Ltd at the time of the study., (© 2023 Yap et al.)- Published
- 2023
- Full Text
- View/download PDF
116. The Mla system of diderm Firmicute Veillonella parvula reveals an ancestral transenvelope bridge for phospholipid trafficking.
- Author
-
Grasekamp KP, Beaud Benyahia B, Taib N, Audrain B, Bardiaux B, Rossez Y, Izadi-Pruneyre N, Lejeune M, Trivelli X, Chouit Z, Guerardel Y, Ghigo JM, Gribaldo S, and Beloin C
- Subjects
- Cell Membrane metabolism, Escherichia coli genetics, Escherichia coli metabolism, Biological Transport, Glycerophospholipids metabolism, Bacteria metabolism, Firmicutes, Bacterial Outer Membrane Proteins genetics, Bacterial Outer Membrane Proteins metabolism, Phospholipids metabolism, Escherichia coli Proteins metabolism
- Abstract
E. coli and most other diderm bacteria (those with two membranes) have an inner membrane enriched in glycerophospholipids (GPLs) and an asymmetric outer membrane (OM) containing GPLs in its inner leaflet and primarily lipopolysaccharides in its outer leaflet. In E. coli, this lipid asymmetry is maintained by the Mla system which consists of six proteins: the OM lipoprotein MlaA extracts GPLs from the outer leaflet, and the periplasmic chaperone MlaC transfers them across the periplasm to the inner membrane complex MlaBDEF. However, GPL trafficking still remains poorly understood, and has only been studied in a handful of model species. Here, we investigate GPL trafficking in Veillonella parvula, a diderm Firmicute with an Mla system that lacks MlaA and MlaC, but contains an elongated MlaD. V. parvula mla mutants display phenotypes characteristic of disrupted lipid asymmetry which can be suppressed by mutations in tamB, supporting that these two systems have opposite GPL trafficking functions across diverse bacterial lineages. Structural modelling and subcellular localisation assays suggest that V. parvula MlaD forms a transenvelope bridge, comprising a typical inner membrane-localised MCE domain and, in addition, an outer membrane ß-barrel. Phylogenomic analyses indicate that this elongated MlaD type is widely distributed across diderm bacteria and likely forms part of the ancestral functional core of the Mla system, which would be composed of MlaEFD only., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
117. Analyses of cell wall synthesis in Clostridioides difficile reveal a diversification in cell division mechanisms in endospore-forming bacteria.
- Author
-
Shrestha S, Taib N, Gribaldo S, and Shen A
- Abstract
Current models of bacterial cell division assume that the core synthases of the multiprotein divisome complex, FtsW-FtsI, are the primary drivers of septal peptidoglycan (PG) synthesis. These enzymes are typically encoded in the highly conserved division and cell wall ( dcw ) cluster and are considered to be universally essential for cell division. Here, we combine bioinformatics analyses with functional characterization in the pathogen Clostridioides difficile to show that dcw -encoded PG synthases have undergone a surprising specialization in the sole endospore-forming phylum, Firmicutes, to fulfill sporulation-specific roles. We describe a novel role for these enzymes in synthesizing septal PG during the sporulation-specific mode of cell division in C. difficile . Although these enzymes are directly regulated by canonical divisome components during this process, dcw -encoded PG synthases and their divisome regulators are unexpectedly dispensable for cell division during normal growth. Instead, C. difficile uses its sole bifunctional class A penicillin-binding protein (aPBP) to drive cell division, revealing a previously unreported role for this class of PG synthases as the core divisome enzyme. Collectively, our findings reveal how the emergence of endosporulation in the Firmicutes phylum was a key driver for the functional repurposing of an otherwise universally conserved cellular process such as cell division. Moreover, they indicate that C. difficile, and likely other clostridia, assemble a divisome that differs markedly from previously studied bacteria, thus representing an attractive, unique target for therapeutic purposes.
- Published
- 2023
- Full Text
- View/download PDF
118. Knowledge, Attitude and Practice of Hand Hygiene among Healthcare Workers Caring for Children with Leukaemia in the Paediatric Oncology Ward of King Saud Medical City, Saudi Arabia.
- Author
-
Aldawsari M, Soh KL, Abdul Raman R, Mohd Taib N, and Aboshaiqah A
- Abstract
Background: Hands are the most common vehicle of pathogen transmission in a healthcare setting. Therefore, hand hygiene is the leading method of reducing healthcare-associated infections. This study aimed to determine the knowledge, attitude and practice (KAP) of hand hygiene and predictors for poor hand hygiene practice among healthcare workers who care for children with leukaemia in the paediatric oncology ward of King Saud Medical City (KSMC) in Saudi Arabia., Methods: One hundred and ninety medical doctors and nurses, who were registered with the Saudi Commission for Health Specialities, were selected to participate in this cross-sectional study using a simple sampling technique. Their KAP of hand hygiene was assessed using a self-structured questionnaire and the collected data was analysed using IBM
® SPSS® version 26.0., Results: Of the 190 healthcare workers, 74.7% were nurses and 25.3% were medical doctors. Among the participants, 53.7% (102) had good knowledge of hand hygiene, 51.6% (98) had positive attitudes towards hand hygiene and 55.8% (106) practised satisfactory hand hygiene. Bachelor education level (adjusted OR = 2.736; 95% CI = 1.101, 6.799; P = 0.030), postgraduate education level (adjusted OR = 6.256; 95% CI = 2.171, 18.028; P = 0.001), poor knowledge (adjusted OR =2.575; 95% CI = 1.263, 5.246; P = 0.009) and negative attitude (adjusted OR = 4.702; 95% CI = 1.263, 5.246; P < 0.001) were the significant predictor variables of unsatisfactory hand hygiene practice among healthcare workers., Conclusion: The performance of hand hygiene among healthcare workers is still far less than optimal, particularly in settings like oncology units. Effective programmes are needed to increase their awareness of hand hygiene KAP, while strict guidelines are needed to reduce nosocomial infections., Competing Interests: Conflict of Interest None., (© Penerbit Universiti Sains Malaysia, 2023.)- Published
- 2023
- Full Text
- View/download PDF
119. The molecular mechanisms of apoptosis accompanied with the epigenetic regulation of the NY-ESO-1 antigen in non-small lung cancer cells treated with decitabine (5-aza-CdR).
- Author
-
Inchakalody VP, Hydrose SP, Krishnankutty R, Merhi M, Therachiyil L, Sasidharan Nair V, Elashi AA, Khan AQ, Taleb S, Raza A, Yoosuf ZSKM, Fernandes Q, Al-Zaidan L, Mestiri S, Taib N, Bedhiafi T, Moustafa D, Assami L, Maalej KM, Elkord E, Uddin S, Al Homsi U, and Dermime S
- Subjects
- Humans, Decitabine pharmacology, Antigens, Neoplasm genetics, Antigens, Neoplasm metabolism, Membrane Proteins metabolism, Azacitidine pharmacology, Apoptosis, Antibodies metabolism, Cell Line, Tumor, Epigenesis, Genetic, Lung Neoplasms drug therapy, Lung Neoplasms genetics
- Abstract
Dysregulated epigenetic modifications are common in lung cancer but have been reversed using demethylating agent like 5-Aza-CdR. 5-Aza-CdR induces/upregulates the NY-ESO-1 antigen in lung cancer. Therefore, we investigated the molecular mechanisms accompanied with the epigenetic regulation of NY-ESO-1 in 5-Aza-CdR-treated NCI-H1975 cell line. We showed significant induction of the NY-ESO-1 protein (**p < 0.0097) using Cellular ELISA. Bisulfite-sequencing demonstrated 45.6% demethylation efficiency at the NY-ESO-1 gene promoter region and RT-qPCR analysis confirmed the significant induction of NY-ESO-1 at mRNA level (128-fold increase, *p < 0.050). We then investigated the mechanism by which 5-Aza-CdR inhibits cell proliferation in the NCI-H1975 cell line. Upregulation of the death receptors TRAIL (2.04-fold *p < 0.011) and FAS (2.1-fold *p < 0.011) indicate activation of the extrinsic apoptotic pathway. The upregulation of Voltage-dependent anion-selective channel protein 1 (1.9-fold), Major vault protein (1.8-fold), Bax (1.16-fold), and Cytochrome C (1.39-fold) indicate the activation of the intrinsic pathway. We also observed the differential expression of protein Complement C3 (3.3-fold), Destrin (-5.1-fold), Vimentin (-1.7-fold), Peroxiredoxin 4 (-1.6-fold), Fascin (-1.8-fold), Heme oxygenase-2 (-0.67-fold**p < 0.0055), Hsp27 (-0.57-fold**p < 0.004), and Hsp70 (-0.39-fold **p < 0.001), indicating reduced cell growth, cell migration, and metastasis. The upregulation of 40S ribosomal protein S9 (3-fold), 40S ribosomal protein S15 (4.2-fold), 40S ribosomal protein S18 (2.5-fold), and 60S ribosomal protein L22 (4.4-fold) implied the induction of translation machinery. These results reiterate the decisive role of 5-Aza-CdR in lung cancer treatment since it induces the epigenetic regulation of NY-ESO-1 antigen, inhibits cell proliferation, increases apoptosis, and decreases invasiveness., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
120. Treatment with decitabine induces the expression of stemness markers, PD-L1 and NY-ESO-1 in colorectal cancer: potential for combined chemoimmunotherapy.
- Author
-
Taib N, Merhi M, Inchakalody V, Mestiri S, Hydrose S, Makni-Maalej K, Raza A, Sahir F, Azizi F, Nizamuddin PB, Fernandes Q, Yoosuf ZSKM, Almoghrabi S, Al-Zaidan L, Shablak A, Uddin S, Maccalli C, Al Homsi MU, and Dermime S
- Subjects
- Male, Humans, Decitabine pharmacology, Decitabine therapeutic use, Membrane Proteins genetics, Membrane Proteins metabolism, Immunotherapy, Cell Line, Tumor, Antigens, Neoplasm metabolism, Colorectal Neoplasms drug therapy, Colorectal Neoplasms genetics
- Abstract
Background: The mechanism of tumor immune escape and progression in colorectal cancer (CRC) is widely investigated in-vitro to help understand and identify agents that might play a crucial role in response to treatment and improve the overall survival of CRC patients. Several mechanisms of immune escape and tumor progression, including expression of stemness markers, inactivation of immunoregulatory genes by methylation, and epigenetic silencing, have been reported in CRC, indicating the potential of demethylating agents as anti-cancer drugs. Of these, a chemotherapeutic demethylating agent, Decitabine (DAC), has been reported to induce a dual effect on both DNA demethylation and histone changes leading to an increased expression of target biomarkers, thus making it an attractive anti-tumorigenic drug., Methods: We compared the effect of DAC in primary 1076 Col and metastatic 1872 Col cell lines isolated and generated from patients' tumor tissues. Both cell lines were treated with DAC, and the expression of the NY-ESO-1 cancer-testis antigen, the PD-L1 immunoinhibitory marker, and the CD44, Nanog, KLF-4, CD133, MSI-1 stemness markers were analyzed using different molecular and immunological assays., Results: DAC treatment significantly upregulated stemness markers in both primary 1076 Col and meta-static 1872 Col cell lines, although a lower effect occurred on the latter: CD44 (7.85 fold; ***p = 0.0001 vs. (4.19 fold; *p = 0.0120), Nanog (4.1 fold; ***p < 0.0001 vs.1.69 fold; ***p = 0.0008), KLF-4 (4.33 fold; ***p < 0.0001 vs.2.48 fold; ***p = 0.0005), CD133 (16.77 fold; ***p = 0.0003 vs.6.36 fold; *p = 0.0166), and MSI-1 (2.33 fold; ***p = 0.0003 vs.2.3 fold; ***p = 0.0004), respectively. Interestingly, in the metastatic 1872 Col cells treated with DAC, the expression of both PD-L1 and NY-ESO-1 was increased tenfold (*p = 0.0128) and fivefold (***p < 0.0001), respectively., Conclusions: We conclude that the upregulation of both stemness and immune checkpoint markers by DAC treatment on CRC cells might represent a mechanism of immune evasion. In addition, induction of NY-ESO-1 may represent an immuno-therapeutic option in metastatic CRC patients. Finally, the combination of DAC and anti-PD-1/anti-PD-L1 antibodies treatment should represent a potential therapeutic intervention for this group of patients., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
121. Reliability and Validity of the Malay BREAST-Q in Women Undergoing Breast Cancer Surgery in Malaysia.
- Author
-
Shunnmugam B, Islam T, Sinnadurai S, Seng Hui C, Mee Hong S, Chinna K, and Aishah Mohd Taib N
- Subjects
- Humans, Female, Malaysia, Reproducibility of Results, Surveys and Questionnaires, Psychometrics methods, Breast Neoplasms surgery
- Abstract
This study aims to translate the BREAST-Q into Malay and validate it in breast cancer patients undergoing surgery. The English BREAST-Q was translated to Malay using the back-translation method. A total of 144 newly diagnosed breast cancer patients were sampled conveniently between December 2015 and November 2016. Test-retest was done after two to three weeks. Data were analyzed using SPSS and AMOS software. Content experts agreed the items in the Malay BREAST-Q were measuring the constructs appropriately. Internal consistencies were good for all items in each subscale (Cronbach's alpha = 0.83-0.95). The highest inter-item correlation for each item with at least one other item in the construct ranged from 0.47 to 0.90. The lowest corrected item-total correlation values ranged from 0.47 to 0.72. The test-retest analysis showed good reproducibility (intraclass correlation coefficient = 0.71-0.98). In exploratory factor analysis, the Kaiser-Meyer-Olkin values were excellent in all four subscales (0.76, 0.92, 0.91, and 0.86). For all subscales, the number of factors extracted cumulatively explained more than 50% of the variance. The Malay BREAST-Q demonstrated good reliability, face validity, content validity, and construct validity.
- Published
- 2023
- Full Text
- View/download PDF
122. Persistence of spike-specific immune responses in BNT162b2-vaccinated donors and generation of rapid ex-vivo T cells expansion protocol for adoptive immunotherapy: A pilot study.
- Author
-
Mestiri S, Merhi M, Inchakalody VP, Taib N, Smatti MK, Ahmad F, Raza A, Ali FH, Hydrose S, Fernandes Q, Ansari AW, Sahir F, Al-Zaidan L, Jalis M, Ghoul M, Allahverdi N, Al Homsi MU, Uddin S, Jeremijenko AM, Nimir M, Abu-Raddad LJ, Abid FB, Zaqout A, Alfheid SR, Saqr HMH, Omrani AS, Hssain AA, Al Maslamani M, Yassine HM, and Dermime S
- Subjects
- Humans, BNT162 Vaccine, CD4-Positive T-Lymphocytes, Pilot Projects, T-Lymphocytes immunology, Immunologic Memory, COVID-19, Immunotherapy, Adoptive
- Abstract
Introduction: The BNT162b2 mRNA-based vaccine has shown high efficacy in preventing COVID-19 infection but there are limited data on the types and persistence of the humoral and T cell responses to such a vaccine., Methods: Here, we dissect the vaccine-induced humoral and cellular responses in a cohort of six healthy recipients of two doses of this vaccine., Results and Discussion: Overall, there was heterogeneity in the spike-specific humoral and cellular responses among vaccinated individuals. Interestingly, we demonstrated that anti-spike antibody levels detected by a novel simple automated assay (Jess) were strongly correlated (r=0.863, P<0.0001) with neutralizing activity; thus, providing a potential surrogate for neutralizing cell-based assays. The spike-specific T cell response was measured with a newly modified T-spot assay in which the high-homology peptide-sequences cross-reactive with other coronaviruses were removed. This response was induced in 4/6 participants after the first dose, and all six participants after the second dose, and remained detectable in 4/6 participants five months post-vaccination. We have also shown for the first time, that BNT162b2 vaccine enhanced T cell responses also against known human common viruses. In addition, we demonstrated the efficacy of a rapid ex-vivo T cell expansion protocol for spike-specific T cell expansion to be potentially used for adoptive-cell therapy in severe COVID-19, immunocompromised individuals, and other high-risk groups. There was a 9 to 13.7-fold increase in the number of expanded T cells with a significant increase of anti-spike specific response showing higher frequencies of both activation and cytotoxic markers. Interestingly, effector memory T cells were dominant in all four participants' CD8+ expanded memory T cells; CD4+ T cells were dominated by effector memory in 2/4 participants and by central memory in the remaining two participants. Moreover, we found that high frequencies of CD4+ terminally differentiated memory T cells were associated with a greater reduction of spike-specific activated CD4+ T cells. Finally, we showed that participants who had a CD4+ central memory T cell dominance expressed a high CD69 activation marker in the CD4+ activated T cells., Competing Interests: SD, SM, MM, VPI, NT, FA, AR, SH, QF, AWA, FS, LA, MJ, MG, NA, MUA, SU, AMJ, MN, ASO, AAH, MAM, FBA, AZ, SRA, and HMHS were employed by Hamad Medical Corporation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Mestiri, Merhi, Inchakalody, Taib, Smatti, Ahmad, Raza, Ali, Hydrose, Fernandes, Ansari, Sahir, Al-Zaidan, Jalis, Ghoul, Allahverdi, Al Homsi, Uddin, Jeremijenko, Nimir, Abu-Raddad, Abid, Zaqout, Alfheid, Saqr, Omrani, Hssain, Al Maslamani, Yassine and Dermime.)
- Published
- 2023
- Full Text
- View/download PDF
123. Publisher Correction: Ancient origin and constrained evolution of the division and cell wall gene cluster in Bacteria.
- Author
-
Megrian D, Taib N, Jaffe AL, Banfield JF, and Gribaldo S
- Published
- 2023
- Full Text
- View/download PDF
124. The complex network of transcription factors, immune checkpoint inhibitors and stemness features in colorectal cancer: A recent update.
- Author
-
Merhi M, Ahmad F, Taib N, Inchakalody V, Uddin S, Shablak A, and Dermime S
- Subjects
- Humans, Programmed Cell Death 1 Receptor, Transcription Factors genetics, Immune Checkpoint Inhibitors pharmacology, Immune Checkpoint Inhibitors therapeutic use, Colorectal Neoplasms drug therapy, Colorectal Neoplasms genetics
- Abstract
Cancer immunity is regulated by several mechanisms that include co-stimulatory and/or co-inhibitory molecules known as immune checkpoints expressed by the immune cells. In colorectal cancer (CRC), CTLA-4, LAG3, TIM-3 and PD-1 are the major co-inhibitory checkpoints involved in tumor development and progression. On the other hand, the deregulation of transcription factors and cancer stem cells activity plays a major role in the development of drug resistance and in the spread of metastatic disease in CRC. In this review, we describe how the modulation of such transcription factors affects the response of CRC to therapies. We also focus on the role of cancer stem cells in tumor metastasis and chemoresistance and discuss both preclinical and clinical approaches for targeting stem cells to prevent their tumorigenic effect. Finally, we provide an update on the clinical applications of immune checkpoint inhibitors in CRC and discuss the regulatory effects of transcription factors on the expression of the immune inhibitory checkpoints with specific focus on the PD-1 and PD-L1 molecules., Competing Interests: Declaration of Competing Interest The authors declare that this work was conducted in the absence of any financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
125. Emerging COVID-19 variants and their impact on SARS-CoV-2 diagnosis, therapeutics and vaccines.
- Author
-
Fernandes Q, Inchakalody VP, Merhi M, Mestiri S, Taib N, Moustafa Abo El-Ella D, Bedhiafi T, Raza A, Al-Zaidan L, Mohsen MO, Yousuf Al-Nesf MA, Hssain AA, Yassine HM, Bachmann MF, Uddin S, and Dermime S
- Subjects
- COVID-19 Testing, COVID-19 Vaccines, Humans, SARS-CoV-2, COVID-19, Vaccines
- Abstract
The emergence of novel and evolving variants of SARS-CoV-2 has fostered the need for change in the form of newer and more adaptive diagnostic methods for the detection of SARS-CoV-2 infections. On the other hand, developing rapid and sensitive diagnostic technologies is now more challenging due to emerging variants and varying symptoms exhibited among the infected individuals. In addition to this, vaccines remain the major mainstay of prevention and protection against infection. Novel vaccines and drugs are constantly being developed to unleash an immune response for the robust targeting of SARS-CoV-2 and its associated variants. In this review, we provide an updated perspective on the current challenges posed by the emergence of novel SARS-CoV-2 mutants/variants and the evolution of diagnostic techniques to enable their detection. In addition, we also discuss the development, formulation, working mechanisms, advantages, and drawbacks of some of the most used vaccines/therapeutic drugs and their subsequent immunological impact.Key messageThe emergence of novel variants of the SARS-CoV-2 in the past couple of months, highlights one of the primary challenges in the diagnostics, treatment, as well as vaccine development against the virus.Advancements in SARS-CoV-2 detection include nucleic acid based, antigen and immuno- assay-based and antibody-based detection methodologies for efficient, robust, and quick testing; while advancements in COVID-19 preventive and therapeutic strategies include novel antiviral and immunomodulatory drugs and SARS-CoV-2 targeted vaccines.The varied COVID-19 vaccine platforms and the immune responses induced by each one of them as well as their ability to battle post-vaccination infections have all been discussed in this review.
- Published
- 2022
- Full Text
- View/download PDF
126. Ancient origin and constrained evolution of the division and cell wall gene cluster in Bacteria.
- Author
-
Megrian D, Taib N, Jaffe AL, Banfield JF, and Gribaldo S
- Subjects
- Phylogeny, Cell Division genetics, Bacteria genetics, Cell Wall genetics, Multigene Family
- Abstract
The division and cell wall (dcw) gene cluster in Bacteria comprises 17 genes encoding key steps in peptidoglycan synthesis and cytokinesis. To understand the origin and evolution of this cluster, we analysed its presence in over 1,000 bacterial genomes. We show that the dcw gene cluster is strikingly conserved in both gene content and gene order across all Bacteria and has undergone only a few rearrangements in some phyla, potentially linked to cell envelope specificities, but not directly to cell shape. A large concatenation of the 12 most conserved dcw cluster genes produced a robust tree of Bacteria that is largely consistent with recent phylogenies based on frequently used markers. Moreover, evolutionary divergence analyses show that the dcw gene cluster offers advantages in defining high-rank taxonomic boundaries and indicate at least two main phyla in the Candidate Phyla Radiation (CPR) matching a sharp dichotomy in dcw gene cluster arrangement. Our results place the origin of the dcw gene cluster in the Last Bacterial Common Ancestor and show that it has evolved vertically for billions of years, similar to major cellular machineries such as the ribosome. The strong phylogenetic signal, combined with conserved genomic synteny at large evolutionary distances, makes the dcw gene cluster a robust alternative set of markers to resolve the ever-growing tree of Bacteria., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2022
- Full Text
- View/download PDF
127. Genetic Screens Identify Additional Genes Implicated in Envelope Remodeling during the Engulfment Stage of Bacillus subtilis Sporulation.
- Author
-
Chan H, Taib N, Gilmore MC, Mohamed AMT, Hanna K, Luhur J, Nguyen H, Hafiz E, Cava F, Gribaldo S, Rudner D, and Rodrigues CDA
- Subjects
- N-Acetylmuramoyl-L-alanine Amidase genetics, Phylogeny, Bacterial Proteins genetics, Bacterial Proteins metabolism, Spores, Bacterial, Bacillus subtilis metabolism, Peptidoglycan metabolism
- Abstract
During bacterial endospore formation, the developing spore is internalized into the mother cell through a phagocytic-like process called engulfment, which involves synthesis and hydrolysis of peptidoglycan. Engulfment peptidoglycan hydrolysis requires the widely conserved and well-characterized DMP complex, composed of SpoIID, SpoIIM, and SpoIIP. In contrast, although peptidoglycan synthesis has been implicated in engulfment, the protein players involved are less well defined. The widely conserved SpoIIIAH-SpoIIQ interaction is also required for engulfment efficiency, functioning like a ratchet to promote membrane migration around the forespore. Here, we screened for additional factors required for engulfment using transposon sequencing in Bacillus subtilis mutants with mild engulfment defects. We discovered that YrvJ, a peptidoglycan hydrolase, and the MurA paralog MurAB, involved in peptidoglycan precursor synthesis, are required for efficient engulfment. Cytological analyses suggest that both factors are important for engulfment when the DMP complex is compromised and that MurAB is additionally required when the SpoIIIAH-SpoIIQ ratchet is abolished. Interestingly, despite the importance of MurAB for sporulation in B. subtilis, phylogenetic analyses of MurA paralogs indicate that there is no correlation between sporulation and the number of MurA paralogs and further reveal the existence of a third MurA paralog, MurAC, within the Firmicutes . Collectively, our studies identify two new factors that are required for efficient envelop remodeling during sporulation and highlight the importance of peptidoglycan precursor synthesis for efficient engulfment in B. subtilis and likely other endospore-forming bacteria. IMPORTANCE In bacteria, cell envelope remodeling is critical for cell growth and division. This is also the case during the development of bacteria into highly resistant endospores (spores), known as sporulation. During sporulation, the developing spore becomes internalized inside the mother cell through a phagocytic-like process called engulfment, which is essential to form the cell envelope of the spore. Engulfment involves both the synthesis and hydrolysis of peptidoglycan and the stabilization of migrating membranes around the developing spore. Importantly, although peptidoglycan synthesis has been implicated during engulfment, the specific genes that contribute to this molecular element of engulfment have remained unclear. Our study identifies two new factors that are required for efficient envelope remodeling during engulfment and emphasizes the importance of peptidoglycan precursor synthesis for efficient engulfment in the model organism Bacillus subtilis and likely other endospore-forming bacteria. Finally, our work highlights the power of synthetic screens to reveal additional genes that contribute to essential processes during sporulation.
- Published
- 2022
- Full Text
- View/download PDF
128. Multi Source Electric Vehicles: Smooth Transition Algorithm for Transient Ripple Minimization.
- Author
-
Oubelaid A, Taib N, Rekioua T, Bajaj M, Blazek V, Prokop L, Misak S, and Ghoneim SSM
- Subjects
- Computer Simulation, Electric Power Supplies, Electricity, Motor Vehicles, Algorithms, Automobile Driving
- Abstract
Any engineering system involves transitions that reduce the performance of the system and lower its comfort. In the field of automotive engineering, the combination of multiple motors and multiple power sources is a trend that is being used to enhance hybrid electric vehicle (HEV) propulsion and autonomy. However, HEV riding comfort is significantly reduced because of high peaks that occur during the transition from a single power source to a multisource powering mode or from a single motor to a multiple motor traction mode. In this study, a novel model-based soft transition algorithm (STA) is used for the suppression of large transient ripples that occur during HEV drivetrain commutations and power source switches. In contrast to classical abrupt switching, the STA detects transitions, measures their rates, generates corresponding transition periods, and uses adequate transition functions to join the actual and the targeted operating points of a given HEV system variable. As a case study, the STA was applied to minimize the transition ripples that occur in a fuel cell-supercapacitor HEV. The transitions that occurred within the HEV were handled using two proposed transition functions which were: a linear-based transition function and a stair-based transition function. The simulation results show that, in addition to its ability to improve driving comfort by minimizing transient torque ripples and DC bus voltage fluctuations, the STA helps to increase the lifetime of the motor and power sources by reducing the currents drawn during the transitions. It is worth noting that the considered HEV runs on four-wheel drive when the load torque applied on it exceeds a specified torque threshold; otherwise, it operates in rear-wheel drive.
- Published
- 2022
- Full Text
- View/download PDF
129. Localization and functional characterization of the alternative oxidase in Naegleria.
- Author
-
Cantoni D, Osborne A, Taib N, Thompson G, Martín-Escolano R, Kazana E, Edrich E, Brown IR, Gribaldo S, Gourlay CW, and Tsaousis AD
- Subjects
- Eukaryota, Mitochondrial Proteins, Oxidoreductases metabolism, Plant Proteins, Naegleria, Naegleria fowleri
- Abstract
The alternative oxidase (AOX) is a protein involved in supporting enzymatic reactions of the Krebs cycle in instances when the canonical (cytochrome-mediated) respiratory chain has been inhibited, while allowing for the maintenance of cell growth and necessary metabolic processes for survival. Among eukaryotes, alternative oxidases have dispersed distribution and are found in plants, fungi, and protists, including Naegleria ssp. Naegleria species are free-living unicellular amoeboflagellates and include the pathogenic species of N. fowleri, the so-called "brain-eating amoeba." Using a multidisciplinary approach, we aimed to understand the evolution, localization, and function of AOX and the role that plays in Naegleria's biology. Our analyses suggest that AOX was present in last common ancestor of the genus and structure prediction showed that all functional residues are also present in Naegleria species. Using cellular and biochemical techniques, we also functionally characterize N. gruberi's AOX in its mitochondria, and we demonstrate that its inactivation affects its proliferation. Consequently, we discuss the benefits of the presence of this protein in Naegleria species, along with its potential pathogenicity role in N. fowleri. We predict that our findings will spearhead new explorations to understand the cell biology, metabolism, and evolution of Naegleria and other free-living relatives., (© 2022 The Authors. Journal of Eukaryotic Microbiology published by Wiley Periodicals LLC on behalf of International Society of Protistologists.)
- Published
- 2022
- Full Text
- View/download PDF
130. Dynamic liquid biopsy components as predictive and prognostic biomarkers in colorectal cancer.
- Author
-
Raza A, Khan AQ, Inchakalody VP, Mestiri S, Yoosuf ZSKM, Bedhiafi T, El-Ella DMA, Taib N, Hydrose S, Akbar S, Fernandes Q, Al-Zaidan L, Krishnankutty R, Merhi M, Uddin S, and Dermime S
- Subjects
- Colorectal Neoplasms pathology, Disease Progression, Early Detection of Cancer, Humans, Prognosis, Biomarkers, Tumor metabolism, Colorectal Neoplasms surgery, Liquid Biopsy methods, Neoplastic Cells, Circulating metabolism
- Abstract
Colorectal cancer (CRC) is one of the most common cancers worldwide. The diagnosis, prognosis and therapeutic monitoring of CRC depends largely on tissue biopsy. However, due to tumor heterogeneity and limitations such as invasiveness, high cost and limited applicability in longitudinal monitoring, liquid biopsy has gathered immense attention in CRC. Liquid biopsy has several advantages over tissue biopsy including ease of sampling, effective monitoring, and longitudinal assessment of treatment dynamics. Furthermore, the importance of liquid biopsy is signified by approval of several liquid biopsy assays by regulatory bodies indicating the powerful approach of liquid biopsy for comprehensive CRC screening, diagnostic and prognostics. Several liquid biopsy biomarkers such as novel components of the microbiome, non-coding RNAs, extracellular vesicles and circulating tumor DNA are extensively being researched for their role in CRC management. Majority of these components have shown promising results on their clinical application in CRC including early detection, observe tumor heterogeneity for treatment and response, prediction of metastases and relapse and detection of minimal residual disease. Therefore, in this review, we aim to provide updated information on various novel liquid biopsy markers such as a) oral microbiota related bacterial network b) gut microbiome-associated serum metabolites c) PIWI-interacting RNAs (piRNAs), microRNA(miRNAs), Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and d) circulating tumor DNAs (ctDNA) and circulating tumor cells (CTC) for their role in disease diagnosis, prognosis, treatment monitoring and their applicability for personalized management of CRC., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
131. An ancient divide in outer membrane tethering systems in bacteria suggests a mechanism for the diderm-to-monoderm transition.
- Author
-
Witwinowski J, Sartori-Rupp A, Taib N, Pende N, Tham TN, Poppleton D, Ghigo JM, Beloin C, and Gribaldo S
- Subjects
- Lipoproteins genetics, Lipoproteins metabolism, Peptidoglycan metabolism, Periplasm metabolism, Phylogeny, Bacteria genetics, Gram-Positive Bacteria metabolism
- Abstract
Recent data support the hypothesis that Gram-positive bacteria (monoderms) arose from Gram-negative ones (diderms) through loss of the outer membrane (OM), but how this happened remains unknown. As tethering of the OM is essential for cell envelope stability in diderm bacteria, its destabilization may have been involved in this transition. In the present study, we present an in-depth analysis of the four known main OM-tethering systems across the Tree of Bacteria (ToB). We show that the presence of such systems follows the ToB with a bimodal distribution matching the deepest phylogenetic divergence between Terrabacteria and Gracilicutes. Whereas the lipoprotein peptidoglycan-associated lipoprotein (Pal) is restricted to the Gracilicutes, along with a more sporadic occurrence of OmpA, and Braun's lipoprotein is present only in a subclade of Gammaproteobacteria, diderm Terrabacteria display, as the main system, the OmpM protein. We propose an evolutionary scenario whereby OmpM represents a simple, ancestral OM-tethering system that was later replaced by one based on Pal after the emergence of the Lol machinery to deliver lipoproteins to the OM, with OmpA as a possible transition state. We speculate that the existence of only one main OM-tethering system in the Terrabacteria would have allowed the multiple OM losses specifically inferred in this clade through OmpM perturbation, and we provide experimental support for this hypothesis by inactivating all four ompM gene copies in the genetically tractable diderm Firmicute Veillonella parvula. High-resolution imaging and tomogram reconstructions reveal a non-lethal phenotype in which vast portions of the OM detach from the cells, forming huge vesicles with an inflated periplasm shared by multiple dividing cells. Together, our results highlight an ancient shift of OM-tethering systems in bacterial evolution and suggest a mechanism for OM loss and the multiple emergences of the monoderm phenotype from diderm ancestors., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)
- Published
- 2022
- Full Text
- View/download PDF
132. A systematic review of the epidemiology of Hepatitis E virus infection in South - Eastern Asia.
- Author
-
Raji YE, Toung OP, Mohd Taib N, and Sekawi ZB
- Subjects
- Asia, Eastern epidemiology, Hepatitis E immunology, Hepatitis E transmission, Hepatitis E virology, Hepatitis E virus immunology, Hepatitis E virus pathogenicity, Humans, Prevalence, Seroepidemiologic Studies, Blood Donors, Hepatitis E epidemiology
- Abstract
Hepatitis E virus (HEV) infection is an emerging zoonotic viral disease, with an increasingly international public health challenge. Despite the concerns that the global disease burden may be underestimated. Therefore, evaluation of the disease epidemiology in South - eastern Asia through a systematic review will assist in unraveling the burden of the disease in the subregion. A priori protocol was prepared for the systematic review and followed by a literature search involving five electronic databases. Identified publications were screened for high quality studies and the elimination of bias and relevant data extracted. A total of 4157 citations were captured, and only 35 were included in the review. A wide range of HEV seroprevalence was recorded from 2% (urban blood donors in Malaysia) to 77.7% (lowland communities in Lao PDR). Sporadic HEV infection and epidemics were also detected in the subregion. Indicating hyperendemicity of the disease in South - eastern Asia.
- Published
- 2021
- Full Text
- View/download PDF
133. Validation of the Malay, English, and Chinese Translations of the 9-Item Shared Decision Making Questionnaire (SDM-Q-9) in Breast Cancer Patients Making Treatment Decisions.
- Author
-
Shunnmugam B, Ng CJ, Aishah Mohd Taib N, and Chinna K
- Subjects
- Aminoacridines, China, Decision Making, Female, Humans, Malaysia, Reproducibility of Results, Surveys and Questionnaires, Breast Neoplasms therapy, Decision Making, Shared
- Abstract
This study aims to test the psychometric properties of the Malay, English, and Chinese 9-Item Shared Decision Making Questionnaire (SDM-Q-9) in breast cancer patients making treatment decisions. The original German SDM-Q-9 was translated to Malay using the back-translation method. A total of 222 newly diagnosed breast cancer patients making treatment decisions were sampled conveniently from three breast clinics between August 2015 and February 2016. A total of 66 patients answered the SDM-Q-9 in Malay, 87 in English, and 69 in Chinese. Data were analyzed using SPSS and AMOS software. SDM-Q-9 demonstrated good reliability in the three translations. All the items correlated well except for Item 1 in English. The factor loadings were within acceptable range except for Item 1 in Malay, Items 1 and 2 in English, and Items 7 and 9 in Chinese SDM-Q-9. However, no items were deleted in accordance with experts' opinions and the previous SDM-Q-9 validation studies. The Malay, English, and Chinese SDM-Q-9 demonstrated good reliability and validity.
- Published
- 2021
- Full Text
- View/download PDF
134. Comparative genomic analysis of Methanimicrococcus blatticola provides insights into host adaptation in archaea and the evolution of methanogenesis.
- Author
-
Thomas CM, Taib N, Gribaldo S, and Borrel G
- Abstract
Other than the Methanobacteriales and Methanomassiliicoccales, the characteristics of archaea that inhabit the animal microbiome are largely unknown. Methanimicrococcus blatticola, a member of the Methanosarcinales, currently reunites two unique features within this order: it is a colonizer of the animal digestive tract and can only reduce methyl compounds with H
2 for methanogenesis, a increasingly recognized metabolism in the archaea and whose origin remains debated. To understand the origin of these characteristics, we have carried out a large-scale comparative genomic analysis. We infer the loss of more than a thousand genes in M. blatticola, by far the largest genome reduction across all Methanosarcinales. These include numerous elements for sensing the environment and adapting to more stable gut conditions, as well as a significant remodeling of the cell surface components likely involved in host and gut microbiota interactions. Several of these modifications parallel those previously observed in phylogenetically distant archaea and bacteria from the animal microbiome, suggesting large-scale convergent mechanisms of adaptation to the gut. Strikingly, M. blatticola has lost almost all genes coding for the H4 MPT methyl branch of the Wood-Ljungdahl pathway (to the exception of mer), a phenomenon never reported before in any member of Class I or Class II methanogens. The loss of this pathway illustrates one of the evolutionary processes that may have led to the emergence of methyl-reducing hydrogenotrophic methanogens, possibly linked to the colonization of organic-rich environments (including the animal gut) where both methyl compounds and hydrogen are abundant., (© 2021. The Author(s).)- Published
- 2021
- Full Text
- View/download PDF
135. Psychometric properties of the adapted Malay Eating Disorder Examination-Questionnaire 6.0 (EDE-Q 6.0) among university students in Malaysia.
- Author
-
Mohd Taib N, Abdul Khaiyom JH, and Fauzaman J
- Subjects
- Humans, Malaysia, Psychometrics, Reproducibility of Results, Students, Surveys and Questionnaires, Universities, Feeding and Eating Disorders diagnosis, Quality of Life
- Abstract
The "Eating Disorder Examination-Questionnaire" (EDE-Q) is a cost-effective eating disorder (ED) screening tool that has a significant relationship with the gold standard "Eating Disorder Examination" (EDE) interview. Though it has been widely used for clinical and research purposes, there is a dearth of effort to establish psychometric properties of the latest EDE-Q 6.0 in the Malaysian sample. The extant study adapted and validated EDE-Q 6.0 on Malaysian university's student population (N = 595) from a public university in the Klang Valley, Malaysia. Four factors of Restraint, Shape and Weight Concerns, Eating Concerns, and Shape/Weight Overvaluation were constituted from exploratory factor analysis. Still, they failed to indicate apparent replication of the original English EDE-Q 6.0. Malay EDE-Q 6.0 exhibited high internal consistency reliability (α = 0.93), acceptable test-retest reliability over 14 days, and acceptable equivalence reliability of its items with the original English version items. The Malay EDE-Q 6.0 global and subscales scores attained acceptable validity with the global scores of Malay EAT-26 (another ED scale) as evidence of convergent validity and with quality of life (QoL) scale for divergent validity. Accordingly, the adapted EDE-Q 6.0 Malay version is considered a valid and reliable instrument for assessing eating disorder psychopathology among Malaysian university students., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
136. A third purine biosynthetic pathway encoded by aminoadenine-based viral DNA genomes.
- Author
-
Sleiman D, Garcia PS, Lagune M, Loc'h J, Haouz A, Taib N, Röthlisberger P, Gribaldo S, Marlière P, and Kaminski PA
- Subjects
- 2-Aminopurine chemistry, 2-Aminopurine metabolism, Adenylosuccinate Synthase classification, Adenylosuccinate Synthase genetics, Bacteriophages genetics, Crystallography, X-Ray, DNA, Viral genetics, Genome, Viral, Phylogeny, Viral Nonstructural Proteins classification, Viral Nonstructural Proteins genetics, 2-Aminopurine analogs & derivatives, Adenylosuccinate Synthase chemistry, Bacteriophages chemistry, Bacteriophages enzymology, Biosynthetic Pathways, DNA, Viral chemistry, Viral Nonstructural Proteins chemistry
- Abstract
Cells have two purine pathways that synthesize adenine and guanine ribonucleotides from phosphoribose via inosylate. A chemical hybrid between adenine and guanine, 2-aminoadenine (Z), replaces adenine in the DNA of the cyanobacterial virus S-2L. We show that S-2L and Vibrio phage PhiVC8 encode a third purine pathway catalyzed by PurZ, a distant paralog of succinoadenylate synthase (PurA), the enzyme condensing aspartate and inosylate in the adenine pathway. PurZ condenses aspartate with deoxyguanylate into dSMP (N6-succino-2-amino-2'-deoxyadenylate), which undergoes defumarylation and phosphorylation to give dZTP (2-amino-2'-deoxyadenosine-5'-triphosphate), a substrate for the phage DNA polymerase. Crystallography and phylogenetics analyses indicate a close relationship between phage PurZ and archaeal PurA enzymes. Our work elucidates the biocatalytic innovation that remodeled a DNA building block beyond canonical molecular biology., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
- Published
- 2021
- Full Text
- View/download PDF
137. Distribution of virulence genes and the molecular epidemiology of Streptococcus pyogenes clinical isolates by emm and multilocus sequence typing methods.
- Author
-
Hamzah SNA, Mohd Desa MN, Jasni AS, Mohd Taib N, Masri SN, and Hamat RA
- Subjects
- Antigens, Bacterial genetics, Bacterial Outer Membrane Proteins genetics, Carrier Proteins genetics, Genotype, Humans, Molecular Epidemiology, Multilocus Sequence Typing, Phylogeny, Virulence genetics, Streptococcal Infections epidemiology, Streptococcus pyogenes genetics
- Abstract
Background: Streptococcus pyogenes has a variety of virulence factors and the predominant invasive strains differ according to specific emm types and geographical orientation. Although emm typing is commonly used as the gold standard method for the molecular characterisation, multilocus sequence typing (MLST) has become an important tool for comparing the genetic profiles globally. This study aimed to screen selected virulence genes from invasive and non-invasive clinical samples and to characterise the molecular epidemiology by emm typing and MLST methods., Materials and Methods: A total of 42 S. pyogenes isolates from invasive and non-invasive samples collected from two different tertiary hospitals were investigated for the distribution of virulence factors and their molecular epidemiology by emm and multilocus sequence typing methods. Detection of five virulence genes (speA, speB, speJ, ssa and sdaB) was performed using multiplex polymerase chain reaction (PCR) using the standard primers and established protocol. Phylogenetic tree branches were constructed from sequence analysis utilised by neighbour joining method generated from seven housekeeping genes using MEGA X software., Results: Multiplex PCR analysis revealed that sdaB/speF (78.6%) and speB (61.9%) were the predominant virulence genes. Regardless of the type of invasiveness, diverse distribution of emm types/subtypes was noted which comprised of 27 different emm types/subtypes. The predominant emm types/subtypes were emm63 and emm18 with each gene accounted for 11.8% whereas 12% for each gene was noted for emm28, emm97.4 and emm91. The MLST revealed that the main sequence type (ST) in invasive samples was ST402 (17.7%) while ST473 and ST318 (12% for each ST) were the major types in non-invasive samples. Out of 18 virulotypes, Virulotype A (five genes, 55.6%) and Virulotype B (two genes, 27.8%) were the major virulotypes found in this study. Phylogenetic analysis indicated the presence of seven different clusters of S. pyogenes. Interestingly, Cluster VI showed that selected emm/ST types such as emm71/ST318 (n=2), emm70.1/ST318 (n=1), emm44/ST31 (n=1) and emm18/ST442 (n=1) have clustered within a common group (Virulotype A) for both hospitals studied., Conclusion: The present study showed that group A streptococcci (GAS) are genetically diverse and possess virulence genes regardless of their invasiveness. Majority of the GAS exhibited no restricted pattern of virulotypes except for a few distinct clusters. Therefore, it can be concluded that virulotyping is partially useful for characterising a heterogeneous population of GAS in hospitals.
- Published
- 2021
138. The expression of hACE2 receptor protein and its involvement in SARS-CoV-2 entry, pathogenesis, and its application as potential therapeutic target.
- Author
-
Al-Zaidan L, Mestiri S, Raza A, Merhi M, Inchakalody VP, Fernandes Q, Taib N, Uddin S, and Dermime S
- Subjects
- COVID-19 metabolism, COVID-19 virology, Humans, Angiotensin-Converting Enzyme 2 metabolism, COVID-19 pathology, SARS-CoV-2 isolation & purification, Spike Glycoprotein, Coronavirus metabolism, Virus Internalization
- Abstract
Pneumonia cases of unknown etiology in Wuhan, Hubei province, China were reported to the World Health Organization on 31st of December 2019. Later the pathogen was reported to be a novel coronavirus designated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Corona virus disease 2019 (COVID-19). The disease outspread was followed by WHO declaration of COVID-19 pandemic as a "Public Health Emergency of International Concern". SARS-CoV-2 is a novel pathogenic beta coronavirus that infects humans causing severe respiratory illness. However, multifarious factors can contribute to the susceptibility to COVID-19 related morbidity and mortality such as age, gender, and underlying comorbidities. Infection initiates when viral particles bind to the host cell surface receptors where SARS-CoV-2 spike glycoprotein subunit 1 binds to the Angiotensin Converting Enzyme 2 (ACE2). It is of importance to mention that SARS-CoV and SARS-CoV-2 viruses' mediate entry into the host cells via ACE2 receptor which might be correlated with the structural similarity of spike glycoprotein subunit 1 of both SARS viruses. However, the structural binding differs, whereas ACE2 receptor binding affinity with SARS-CoV-2 is 4 folds higher than that with SARS-CoV. Moreover, amino acids sequence divergence between the two S glycoproteins might be responsible for differential modulations of the specific immune response to both viruses. Identification of different aspects such as binding affinity, differential antigenic profiles of S-glycoproteins, and ACE2 mutations might influence the investigation of potential therapeutic strategies targeting SARS-CoV-2/ACE2 binding interface. In this review, we aim to elaborate on the expression of hACE2 receptor protein and its binding with SARS-CoV-2 S1 subunit, the possible immunogenic sequences of spike protein, effect of ACE 2 polymorphism on viral binding, and infectivity/susceptibility to disease. Furthermore, targeting of hACE2 receptor binding with SARS-CoV-2 S1 subunit via various mechanisms will be discussed to understand its role in therapeutics.
- Published
- 2021
- Full Text
- View/download PDF
139. Single-Stranded DNA-Binding Proteins in the Archaea.
- Author
-
Taib N, Gribaldo S, and MacNeill SA
- Subjects
- Archaea classification, Archaea genetics, Archaeal Proteins chemistry, Archaeal Proteins metabolism, DNA Repair, DNA Replication, DNA, Archaeal metabolism, DNA, Single-Stranded chemistry, Models, Molecular, Phylogeny, Protein Binding, Protein Domains, Species Specificity, Archaea metabolism, DNA, Single-Stranded metabolism, DNA-Binding Proteins chemistry, DNA-Binding Proteins metabolism
- Abstract
Single-stranded (ss) DNA-binding proteins are found in all three domains of life where they play vital roles in nearly all aspects of DNA metabolism by binding to and stabilizing exposed ssDNA and acting as platforms onto which DNA-processing activities can assemble. The ssDNA-binding factors SSB and RPA are extremely well conserved across bacteria and eukaryotes, respectively, and comprise one or more OB-fold ssDNA-binding domains. In the third domain of life, the archaea, multiple types of ssDNA-binding protein are found with a variety of domain architectures and subunit compositions, with OB-fold ssDNA-binding domains being a characteristic of most, but not all. This chapter summarizes current knowledge of the distribution, structure, and biological function of the archaeal ssDNA-binding factors, highlighting key features shared between clades and those that distinguish the proteins of different clades from one another. The likely cellular functions of the proteins are discussed and gaps in current knowledge identified.
- Published
- 2021
- Full Text
- View/download PDF
140. Genome-wide analysis of the Firmicutes illuminates the diderm/monoderm transition.
- Author
-
Taib N, Megrian D, Witwinowski J, Adam P, Poppleton D, Borrel G, Beloin C, and Gribaldo S
- Subjects
- Bacteria, Gram-Negative Bacteria, Humans, Phylogeny, Firmicutes, Gram-Positive Bacteria
- Abstract
The transition between cell envelopes with one membrane (Gram-positive or monoderm) and those with two membranes (Gram-negative or diderm) is a fundamental open question in the evolution of Bacteria. Evidence of the presence of two independent diderm lineages, the Halanaerobiales and the Negativicutes, within the classically monoderm Firmicutes has blurred the monoderm/diderm divide and specifically anticipated that other members with an outer membrane (OM) might exist in this phylum. Here, by screening 1,639 genomes of uncultured Firmicutes for signatures of an OM, we highlight a third and deep branching diderm clade, the Limnochordia, strengthening the hypothesis of a diderm ancestor and the occurrence of independent transitions leading to the monoderm phenotype. Phyletic patterns of over 176,000 protein families constituting the Firmicutes pan-proteome identify those that strongly correlate with the diderm phenotype and suggest the existence of new potential players in OM biogenesis. In contrast, we find practically no largely conserved core of monoderms, a fact possibly linked to different ways of adapting to repeated OM losses. Phylogenetic analysis of a concatenation of main OM components totalling nearly 2,000 amino acid positions illustrates the common origin and vertical evolution of most diderm bacterial envelopes. Finally, mapping the presence/absence of OM markers onto the tree of Bacteria shows the overwhelming presence of diderm phyla and the non-monophyly of monoderm ones, pointing to an early origin of two-membraned cells and the derived nature of the Gram-positive envelope following multiple OM losses.
- Published
- 2020
- Full Text
- View/download PDF
141. Autotransporters Drive Biofilm Formation and Autoaggregation in the Diderm Firmicute Veillonella parvula.
- Author
-
Béchon N, Jiménez-Fernández A, Witwinowski J, Bierque E, Taib N, Cokelaer T, Ma L, Ghigo JM, Gribaldo S, and Beloin C
- Subjects
- Adhesins, Bacterial genetics, Adhesins, Bacterial metabolism, Bacterial Adhesion genetics, Biofilms growth & development, Type V Secretion Systems genetics, Type V Secretion Systems metabolism, Veillonella physiology
- Abstract
The Negativicutes are a clade of the Firmicutes that have retained the ancestral diderm character and possess an outer membrane. One of the best studied Negativicutes , Veillonella parvula , is an anaerobic commensal and opportunistic pathogen inhabiting complex human microbial communities, including the gut and the dental plaque microbiota. Whereas the adhesion and biofilm capacities of V. parvula are expected to be crucial for its maintenance and development in these environments, studies of V. parvula adhesion have been hindered by the lack of efficient genetic tools to perform functional analyses in this bacterium. Here, we took advantage of a recently described naturally transformable V. parvula isolate, SKV38, and adapted tools developed for the closely related Clostridia spp. to perform random transposon and targeted mutagenesis to identify V. parvula genes involved in biofilm formation. We show that type V secreted autotransporters, typically found in diderm bacteria, are the main determinants of V. parvula autoaggregation and biofilm formation and compete with each other for binding either to cells or to surfaces, with strong consequences for V. parvula biofilm formation capacity. The identified trimeric autotransporters have an original structure compared to classical autotransporters identified in Proteobacteria , with an additional C-terminal domain. We also show that inactivation of the gene coding for a poorly characterized metal-dependent phosphohydrolase HD domain protein conserved in the Firmicutes and their closely related diderm phyla inhibits autotransporter-mediated biofilm formation. This study paves the way for further molecular characterization of V. parvula interactions with other bacteria and the host within complex microbiota environments. IMPORTANCE Veillonella parvula is an anaerobic commensal and opportunistic pathogen whose ability to adhere to surfaces or other bacteria and form biofilms is critical for it to inhabit complex human microbial communities such as the gut and oral microbiota. Although the adhesive capacity of V. parvula has been previously described, very little is known about the underlying molecular mechanisms due to a lack of genetically amenable Veillonella strains. In this study, we took advantage of a naturally transformable V. parvula isolate and newly adapted genetic tools to identify surface-exposed adhesins called autotransporters as the main molecular determinants of adhesion in this bacterium. This work therefore provides new insights on an important aspect of the V. parvula lifestyle, opening new possibilities for mechanistic studies of the contribution of biofilm formation to the biology of this major commensal of the oral-digestive tract., (Copyright © 2020 Béchon et al.)
- Published
- 2020
- Full Text
- View/download PDF
142. Transient Dynamics of Archaea and Bacteria in Sediments and Brine Across a Salinity Gradient in a Solar Saltern of Goa, India.
- Author
-
Mani K, Taib N, Hugoni M, Bronner G, Bragança JM, and Debroas D
- Abstract
The microbial fluctuations along an increasing salinity gradient during two different salt production phases - initial salt harvesting (ISH) phase and peak salt harvesting (PSH) phase of Siridao solar salterns in Goa, India were examined through high-throughput sequencing of 16S rRNA genes on Illumina MiSeq platform. Elemental analysis of the brine samples showed high concentration of sodium (Na
+ ) and chloride (Cl- ) ions thereby indicating its thalassohaline nature. Comparison of relative abundance of sequences revealed that Archaea transited from sediment to brine while Bacteria transited from brine to sediment with increasing salinity. Frequency of Archaea was found to be significantly enriched even in low and moderate salinity sediments with their relative sequence abundance reaching as high as 85%. Euryarchaeota was found to be the dominant archaeal phylum containing 19 and 17 genera in sediments and brine, respectively. Phylotypes belonging to Halorubrum , Haloarcula , Halorhabdus , and Haloplanus were common in both sediments and brine. Occurence of Halobacterium and Natronomonas were exclusive to sediments while Halonotius was exclusive to brine. Among sediments, relative sequence frequency of Halorubrum , and Halorhabdus decreased while Haloarcula , Haloplanus , and Natronomonas increased with increasing salinity. Similarly, the relative abundance of Haloarcula and Halorubrum increased with increasing salinity in brine. Sediments and brine samples harbored about 20 and 17 bacterial phyla, respectively. Bacteroidetes , Proteobacteria , and Chloroflexi were the common bacterial phyla in both sediments and brine while Firmicutes were dominant albeit in sediments alone. Further, Gammaproteobacteria , Alphaproteobacteria , and Deltaproteobacteria were observed to be the abundant class within the Proteobacteria . Among the bacterial genera, phylotypes belonging to Rubricoccus and Halomonas were widely detected in both brine and sediment while Thioalkalispira , Desulfovermiculus , and Marinobacter were selectively present in sediments. This study suggests that Bacteria are more susceptible to salinity fluctuations than Archaea, with many bacterial genera being compartment and phase-specific. Our study further indicated that Archaea rather than Bacteria could withstand the wide salinity fluctuation and attain a stable community structure within a short time-frame., (Copyright © 2020 Mani, Taib, Hugoni, Bronner, Bragança and Debroas.)- Published
- 2020
- Full Text
- View/download PDF
143. Intake of Common Alcoholic and Non-Alcoholic Beverages and Breast Cancer Risk among Japanese Women: Findings from the Japan Collaborative Cohort Study.
- Author
-
Sinnadurai S, Okabayashi S, Kawamura T, Mori M, Bhoo-Pathy N, Aishah Taib N, Ukawa S, Tamakoshi A, and The Jacc Study Group -
- Subjects
- Adult, Aged, Breast Neoplasms etiology, Female, Follow-Up Studies, Humans, Japan epidemiology, Middle Aged, Prognosis, Prospective Studies, Risk Factors, Surveys and Questionnaires, Alcohol Drinking adverse effects, Beverages adverse effects, Breast Neoplasms epidemiology
- Abstract
This study investigated the association between intake of common alcoholic and non-alcoholic beverages and breast cancer risk among Japanese women. This study included 33,396 Japanese women aged 40-79 years from 24 areas in Japan from the Collaborative Cohort study. During the follow-up period (≥20 years), 245 incidents or mortal breast cancers were documented. Multivariable logistic regression analysis was performed to assess the independent association between breast cancer risk and the intake of Japanese green tea, coffee, and alcohol. Japanese green tea was the most commonly consumed non-alcoholic beverage (81.6% of participants), followed by coffee (34.7%) and alcohol (23.6%). No significant associations were identified between the intake of green tea and coffee with breast cancer risk (odds ratio OR 1.15, 95% confidence interval [CI] 0.82-1.60, and OR 0.84, 95% CI 0.64-1.10, respectively). Alcohol intake was associated with significant breast cancer risk (OR 1.46, 95% CI 1.11-1.92), and even infrequent alcohol consumption (.
- Published
- 2020
- Full Text
- View/download PDF
144. Significant Clinical Presentation of Leptospirosis in Relation to Sociodemographic and Risk Factors in a Tertiary Hospital, Malaysia.
- Author
-
Mohd Taib N, Ahmad H, Soh KL, Md Shah A, Amin Nordin S, Than Thian Lung L, Abdullah M, Chong CW, and Sekawi Z
- Subjects
- Adult, Female, Humans, Malaysia epidemiology, Male, Risk Factors, Socioeconomic Factors, Tertiary Care Centers, Young Adult, Leptospirosis epidemiology
- Abstract
Introduction: Incidence of leptospirosis has increased within the past few years in many countries. Its clinical presentations were generally nonspecific, making it difficult to assist in the diagnosis. Besides the determination of the common clinical features, the sociodemographic background is essential to identify high-risk populations to assist in prevention. Methods: Data for this study were obtained from electronic medical records among patients clinically diagnosed with leptospirosis at a tertiary hospital in Malaysia from the years 2011 to 2015 and were recorded using standard pro forma. Associations between clinical features and sociodemographics were performed using bivariate analysis and logistic regression. Results: Data were collected from 283 patients. Their mean age was 30.71 years old. Out of 283 patients, 206 (72.8%) were male. Involvement in outdoor events and water activities was the highest risk factor of acquiring leptospirosis in 64 (22.7%) patients followed by 59 (20.8%) patients who were staying in crowded housing areas with poor sanitation. Although fever was the main clinical presentation in 274 (96.8%) patients with leptospirosis, gastrointestinal (GIT) symptoms were the second most frequent in 159 (56.2%) patients followed by pulmonary symptoms, myalgia, headache, and jaundice. From the total number of 283 patients, only 21 (92.6%) presented with severe leptospirosis. GIT symptoms were a significant predictor for leptospirosis severity, while the age group was the significant sociodemographic factor toward GIT presentation in leptospirosis. The relationship between GIT symptoms and crowded housing areas with poor sanitation was also significant. Multivariable logistic regression showed that crowded housing areas with poor sanitation (odds ratio [OR] = 3.570, p < 0.001) and age between 20 and 40 years old (OR = 2.056, p = 0.014) were more likely to have GIT symptoms. Conclusions: Information regarding the clinical features of leptospirosis to the public is necessary, while targeted prevention by educational outreach among 20-40 year olds especially those participating in outdoor water activities are crucial to decrease the incidence and complications of leptospirosis.
- Published
- 2020
- Full Text
- View/download PDF
145. In Silico Identification of a Key Residue for Substrate Recognition of the Riboflavin Membrane Transporter RFVT3.
- Author
-
Dilly S, Garnier M, Solé M, Bailly R, Taib N, and Bestel I
- Subjects
- Computer Simulation, Humans, Membrane Transport Proteins genetics, Riboflavin metabolism, Bulbar Palsy, Progressive, Riboflavin Deficiency
- Abstract
Because of its specific physicochemical properties (fluorescence, photosensitizing, and redox reactions), vitamin B2, also called riboflavin (RF), has been generating a lot of interest in the fields of nanotechnology and bioengineering in the last decade. RF, by targeting its riboflavin transporters (RFVTs) overexpressed in some cancers, is particularly used to functionalize nanovectors for anticancer drug delivery. From a physiopathological point of view, an RF deficiency has been implicated in various pathologies, including mendelian diseases. RF deficiency is mainly due to natural variants of its RFVTs that make them inactive and therefore prevent RF transport. The lack of structural data about RFVT is a major drawback for a better understanding of the role of the mutations in the molecular mechanism of these transporters. In this context, this work was aimed at investigating the 3D structure of RFVT3 and its interactions with RF. For this purpose, we used an in silico procedure including protein threading, docking, and molecular dynamics. Our results propose that the natural variant W17R, known to be responsible for the Brown-Vialetto-Van Laere syndrome, prevents the recognition of RF by RFVT3 and thus blocks its transport. This in silico procedure could be used for elucidating the impact of pathogenic mutations of other proteins. Moreover, the identification of RF binding sites will be useful for the design of RF-functionalized nanovectors.
- Published
- 2020
- Full Text
- View/download PDF
146. Elevated levels of IL-8 in fatal leptospirosis.
- Author
-
Wan Yusoff WSY, Abdullah M, Sekawi Z, Amran F, Yuhana MY, Mohd Taib N, Md Shah A, and Amin Nordin S
- Subjects
- Adolescent, Adult, Aged, Female, Humans, Leptospirosis epidemiology, Malaysia epidemiology, Male, Middle Aged, Young Adult, Interleukin-8 blood, Leptospirosis blood, Leptospirosis mortality
- Abstract
Leptospirosis causes a wide range of clinical outcomes, including organ failure and death. Early treatment significantly increases the chances of cure. Interleukin-8 (IL-8) is a chemoattractant cytokine for neutrophil and is associated with multiple organ failure. Research has indicated IL-8 to be raised in severe and fatal cases of leptospirosis, but its suitability as a prognostic biomarker has yet to be confirmed. This study aimed to evaluate the significance of IL-8 with the clinical outcomes of leptospirosis patients. Plasma IL-8 was measured in fifty-two samples from hospitalized patients and nineteen healthy controls. The comparisons were made between mild, severe-survived and fatal groups identified by clinical or laboratory findings. IL-8 was significantly higher in fatal (p = 0.01) compared to mild cases. IL-8 was also significantly higher in fatal (p = 0.02) when compared to survived cases of leptospirosis. IL-8 levels in the plasma of fatal leptospirosis cases were significantly elevated compared to survived cases and may serve as a potential prognostic biomarker in determining the possible outcome of leptospirosis patients.
- Published
- 2020
- Full Text
- View/download PDF
147. One or two membranes? Diderm Firmicutes challenge the Gram-positive/Gram-negative divide.
- Author
-
Megrian D, Taib N, Witwinowski J, Beloin C, and Gribaldo S
- Subjects
- Bacteria genetics, Bacteria metabolism, Biological Evolution, Cell Membrane ultrastructure, Cell Wall genetics, Cell Wall ultrastructure, Evolution, Molecular, Firmicutes classification, Firmicutes genetics, Gram-Negative Bacteria genetics, Gram-Negative Bacteria metabolism, Gram-Positive Bacteria genetics, Gram-Positive Bacteria metabolism, Lipopolysaccharides, Phylogeny, Cell Membrane genetics, Gram-Negative Bacteria ultrastructure, Gram-Positive Bacteria ultrastructure
- Abstract
How, when and why the transition between cell envelopes with one membrane (Gram-positives or monoderms) and two (Gram-negative or diderms) occurred in Bacteria is a key unanswered question in evolutionary biology. Different hypotheses have been put forward, suggesting that either the monoderm or the diderm phenotype is ancestral. The existence of diderm members in the classically monoderm Firmicutes challenges the Gram-positive/Gram-negative divide and provides a great opportunity to tackle the issue. In this review, we present current knowledge on the diversity of bacterial cell envelopes, including these atypical Firmicutes. We discuss how phylogenomic analysis supports the hypothesis that the diderm cell envelope architecture is an ancestral character in the Firmicutes, and that the monoderm phenotype in this phylum arose multiple times independently by loss of the outer membrane. Given the overwhelming distribution of diderm phenotypes with respect to monoderm ones, this scenario likely extends to the ancestor of all bacteria. Finally, we discuss the recent development of genetic tools for Veillonella parvula, a diderm Firmicute member of the human microbiome, which indicates it as an emerging new experimental model to investigate fundamental aspects of the diderm/monoderm transition., (© 2020 John Wiley & Sons Ltd.)
- Published
- 2020
- Full Text
- View/download PDF
148. Hypocalcemia, hypochloremia, and eosinopenia as clinical predictors of leptospirosis: A retrospective study.
- Author
-
Fish-Low CY, Balami AD, Than LTL, Ling KH, Mohd Taib N, Md Shah A, and Sekawi Z
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Humans, Leptospira isolation & purification, Leptospirosis blood, Logistic Models, Male, Middle Aged, Prognosis, ROC Curve, Retrospective Studies, Young Adult, Agranulocytosis blood, Chlorides blood, Eosinophils pathology, Hypocalcemia blood, Leptospirosis diagnosis
- Abstract
Background: Underestimation of leptospirosis cases is happening in many countries. The most common factor of underreporting is misdiagnosis. Considering the limitations of direct detection of pathogen and serological diagnosis for leptospirosis, clinical features and blood tests though non-specific are usually referred in making presumptive diagnosis to decide disease management., Methods: In this single-centre retrospective study, comparative analysis on clinical presentations and laboratory findings was performed between confirmed leptospirosis versus non-leptospirosis cases., Results: In multivariate logistic regression evidenced by a Hosmer-Lemeshow significance value of 0.979 and Nagelkerke R square of 0.426, the predictors of a leptospirosis case are hypocalcemia (calcium <2.10mmol/L), hypochloremia (chloride <98mmol/L), and eosinopenia (absolute eosinophil count <0.040×10
9 /L). The proposed diagnostic scoring model has a discriminatory power with area under the curve (AUC) 0.761 (p<0.001). A score value of 6 reflected a sensitivity of 0.762, specificity of 0.655, a positive predictive value of 0.38, negative predictive value of 0.91, a positive likelihood ratios of 2.21, and a negative likelihood ratios of 0.36., Conclusion: With further validation in clinical settings, implementation of this diagnostic scoring model is helpful to manage presumed leptospirosis especially in the absence of leptospirosis confirmatory tests., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
149. Raised levels of Il-6, Il-17a, and Il-22 in fatal leptospirosis.
- Author
-
Wan Yusoff WSY, Abdullah M, Sekawi Z, Amran F, Yuhana MY, Mohd Taib N, Yap IKS, Than LTL, Md Shah A, van Belkum A, and Amin Nordin S
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Biomarkers blood, Case-Control Studies, Female, Humans, Interleukin-17 blood, Interleukin-6 blood, Interleukins blood, Leptospirosis pathology, Leptospirosis physiopathology, Malaysia epidemiology, Male, Middle Aged, Multivariate Analysis, Odds Ratio, Young Adult, Interleukin-22, Cytokines blood, Leptospirosis blood, Leptospirosis mortality
- Abstract
Clinical manifestations of leptospirosis range from mild, common cold-like illness, to a life-threatening condition. The host immune response has been hypothesized to play a major role in leptospirosis outcome. Increased levels of inflammatory mediators, such as cytokines, may promote tissue damage that lead to increased disease severity. The question is whether cytokines levels may predict the outcome of leptospirosis and guide patient management. This study aimed to assess the association between Th1-, Th2-, and Th17-related cytokines with the clinical outcome of patients with leptospirosis. Different cytokine levels were measured in fifty-two plasma samples of hospitalized patients diagnosed with leptospirosis in Malaysia (January 2016-December 2017). Patients were divided into two separate categories: survived (n = 40) and fatal outcome (n = 12). Nineteen plasma samples from healthy individuals were obtained as controls. Cytokine quantification was performed using Simple Plex™ assays from ProteinSimple (San Jose, CA, USA). Measurements were done in triplicate and statistical analysis was performed using GraphPad software and SPSS v20. IL-6 (p = 0.033), IL-17A (p = 0.022), and IL-22 (p = 0.046) were significantly elevated in fatal cases. IL-17A concentration (OR 1.115; 95% CI 1.010-1.231) appeared to be an independent predictor of fatality of leptospirosis. Significantly higher levels of TNF-α (p ≤ 0.0001), IL-6 (p ≤ 0.0001), IL-10 (p ≤ 0.0001), IL-12 (p ≤ 0.0001), IL17A (p ≤ 0.0001), and IL-18 (p ≤ 0.0001) were observed among leptospirosis patients in comparison with healthy controls. Our study shows that certain cytokine levels may serve as possible prognostic biomarkers in leptospirosis patients.
- Published
- 2019
- Full Text
- View/download PDF
150. Draft genome sequences for three unisolated Alnus -infective Frankia Sp+ strains, AgTrS, AiOr and AvVan, the first sequenced Frankia strains able to sporulate in-planta .
- Author
-
Bethencourt L, Vautrin F, Taib N, Dubost A, Castro-Garcia L, Imbaud O, Abrouk D, Fournier P, Briolay J, Nguyen A, Normand P, Fernandez MP, Brochier-Armanet C, and Herrera-Belaroussi A
- Abstract
Actinobacteria from genus Frankia are able to form symbiotic associations with actinorhizal plants including alders. Among them, Sp+ strains are characterized by their ability to differentiate numerous sporangia inside host plant cells (unlike "Sp-" strains unable of in-planta sporulation). Here, we report the first genome sequences of three unisolated Sp+ strains: AgTrS, AiOr and AvVan obtained from Alnus glutinosa , A. incana and A. alnobetula (previously known as viridis ), respectively (with genome completeness estimated at more than 98%). They represent new Frankia species based on Average Nucleotide Identity (ANI) calculations, and the smallest Alnus -infective Frankia genomes so far sequenced (~5 Mbp), with 5,178, 6,192 and 5,751 candidate protein-encoding genes for AgTrS, AiOr and AvVan, respectively., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.