Search

Streptococcus pneumoniae (S. pneumoniae), which is a Gram-positive diplococcus, has emerged as a significant human pathogen. It is a primary cause of bacterial pneumonia, otitis media, meningitis, and septicemia, leading to a considerable impact on global morbidity and mortality. The investigation of S. pneumoniae and its virulence factors has resulted in the identification of surface endonuclease A (EndA). EndA functions in DNA uptake during natural transformation and plays a significant role in gene transfer. The ability of S. pneumoniae to degrade neutrophil extracellular traps (NETs) enhances its virulence and invasive potential in pneumococcal infections. NETosis occurs when neutrophils release chromatin into the extracellular space to form NETs, capturing and neutralizing pathogens. Currently, NETosis can be induced by several microbes, particulate matter, and sterile stimuli through distinct cellular mechanisms, and this includes the involvement of EndA in S. pneumoniae. Here, we reviewed the cellular functions of EndA, its role in S. pneumoniae as a virulence factor in relation to NETosis, its relationship to immunogenicity, and its involvement in several diseases. The discovery of this relationship would significantly impact therapeutic technology in reducing disease burden, especially pneumococcal infections.

Summary: Live imaging of regenerative processes can reveal how animals restore their bodies after injury through a cascade of dynamic cellular events. Here, we present a comprehensive toolkit for live imaging of tissue regeneration in the flatworm Macrostomum lignano, including a high-throughput cloning pipeline, targeted cellular ablation, and advanced microscopy solutions. Using tissue-specific reporter expression, we examine how various structures regenerate. Enabled by a custom luminescence/fluorescence microscope, we overcome intense stress-induced autofluorescence to demonstrate genetic cellular ablation and reveal the limited regenerative capacity of neurons and their essential role during wound healing, contrasting muscle cells’ rapid regeneration after ablation. Finally, we build an open-source tracking microscope to continuously image freely moving animals throughout the week-long process of regeneration, quantifying kinetics of wound healing, nerve cord repair, body regeneration, growth, and behavioral recovery. Our findings suggest that nerve cord reconnection is highly robust and proceeds independently of regeneration.

Bacterial small RNAs (sRNAs) play crucial roles in coordinating gene regulatory networks in various physiological processes, including biofilm formation. In this study, RNA sequencing was performed on biofilm (n = 4) and planktonic (n = 4) cells harvested at 10 h (pre-stationary phase of biofilm development) to identify biofilm-associated sRNAs in human methicillin-susceptible Staphylococcus aureus (MSSA) recovered from urine isolate. A total of 56 highly expressed sRNAs were identified with 15 overlapping sRNA genes (srn_9348, sprD, sRNA205, sRNA288, srn_2467, Sau-25, srn_2468, sRNA260, sRNA200, RsaE, sRNA397, Teg55, Teg60, RsaX05 and Teg140). Further validation through RT-qPCR analysis of nine sRNAs revealed that srn_9348 and sRNA260 were significantly expressed in the biofilm cells of urine sample. Both sRNAs were predicted to interact with mRNA genes including intracellular adhesin A (icaA) and host factor protein (hfq) involved in biofilm formation via cis-acting and trans-acting using CopraRNA analysis. Therefore, both sRNAs merit further investigations via reverse genetic approaches to elucidate their mechanism of translational regulation. In summary, the transcriptomic analysis conducted in this study offers new insights into the potential regulatory roles of sRNAs in MSSA biofilm development within the urinary environment.

Abstract Klebsiella pneumoniae is a Gram-negative Enterobacteriaceae that is classified by the World Health Organisation (WHO) as a Priority One ESKAPE pathogen. South and Southeast Asian countries are regions where both healthcare associated infections (HAI) and community acquired infections (CAI) due to extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant K. pneumoniae (CRKp) are of concern. As K. pneumoniae can also exist as a harmless commensal, the spread of resistance genotypes requires epidemiological vigilance. However there has been no significant study of carriage isolates from healthy individuals, particularly in Southeast Asia, and specially Malaysia. Here we describe the genomic analysis of respiratory isolates of K. pneumoniae obtained from Orang Ulu and Orang Asli communities in Malaysian Borneo and Peninsular Malaysia respectively. The majority of isolates were K. pneumoniae species complex (KpSC) 1 K. pneumoniae (n = 53, 89.8%). Four Klebsiella variicola subsp. variicola (KpSC3) and two Klebsiella quasipneumoniae subsp. similipneumoniae (KpSC4) were also found. It was discovered that 30.2% (n = 16) of the KpSC1 isolates were ST23, 11.3% (n = 6) were of ST65, 7.5% (n = 4) were ST13, and 13.2% (n = 7) were ST86. Only eight of the KpSC1 isolates encoded ESBL, but importantly not carbapenemase. Thirteen of the KpSC1 isolates carried yersiniabactin, colibactin and aerobactin, all of which harboured the rmpADC locus and are therefore characterised as hypervirulent. Co-carriage of multiple strains was minimal. In conclusion, most isolates were KpSC1, ST23, one of the most common sequence types and previously found in cases of K. pneumoniae infection. A proportion were hypervirulent (hvKp) however antibiotic resistance was low.

Summary: Animal behavior emerges from collective dynamics of neurons, making it vulnerable to damage. Paradoxically, many organisms exhibit a remarkable ability to maintain significant behavior even after large-scale neural injury. Molecular underpinnings of this extreme robustness remain largely unknown. Here, we develop a quantitative pipeline to measure long-lasting latent states in planarian flatworm behaviors during whole-brain regeneration. By combining >20,000 animal trials with neural network modeling, we show that long-range volumetric peptidergic signals allow the planarian to rapidly restore coarse behavior output after large perturbations to the nervous system, while slow restoration of small-molecule neuromodulator functions refines precision. This relies on the different time and length scales of neuropeptide and small-molecule transmission to generate incoherent patterns of neural activity that competitively regulate behavior. Controlling behavior through opposing communication mechanisms creates a more robust system than either alone and may serve as a generalizable approach for constructing robust neural networks.

Abstract Despite the importance of methicillin-resistant Staphylococcus aureus (MRSA) as a priority nosocomial pathogen, the genome sequences of Malaysian MRSA isolates are currently limited to a small pool of samples. Here, we present the genome sequence analyses of 88 clinical MRSA isolates obtained from the main tertiary hospital in Terengganu, Malaysia in 2016–2020, to obtain in-depth insights into their characteristics. The EMRSA-15 (ST22-SCCmec IV) clone of the clonal complex 22 (CC22) lineage was predominant with a total of 61 (69.3%) isolates. Earlier reports from other Malaysian hospitals indicated the predominance of the ST239 clone, but only two (2.3%) isolates were identified in this study. Two Indian-origin clones, the Bengal Bay clone ST772-SCCmec V (n = 2) and ST672 (n = 10) were also detected, with most of the ST672 isolates obtained in 2020 (n = 7). Two new STs were found, with one isolate each, and were designated ST7879 and ST7883. From the core genome phylogenetic tree, the HSNZ MRSA isolates could be grouped into seven clades. Antimicrobial phenotype-genotype concordance was high (> 95%), indicating the accuracy of WGS in predicting most resistances. Majority of the MRSA isolates were found to harbor more than 10 virulence genes, demonstrating their pathogenic nature.

ABSTRACTMethicillin-resistant Staphylococcus aureus (MRSA) is among the top threats to global public health and biofilm production is one of the factors attributed to its pathogenesis. This study aims to investigate the biofilm forming ability of 89 clinical MRSA isolated from various sources in Malaysia and to investigate the presence of biofilm-associated and regulatory genes among these isolates. A total of 89.9% (80/89) isolates produced slime layer via Congo red assay while 57.3% (51/89) isolates produced strong biofilm via crystal violet assay. PCR assay revealed 97.8% (87/89) isolates carried at least one of the MSCRAMM with icaBC genes detected at the highest rate (92.1%, 82/89) and highest frequency of agr-I (68.5%, 61/89). Clinical isolates isolated from pus were significantly associated with strong biofilm (p = 0.0449). The obtained results revealed the varying ability of clinical MRSA isolates to form biofilms and highlighted the genetic background associated with biofilms from different sources and clinical presentations.

ABSTRACT: Objectives: To analyse the genome sequences of four archival Acinetobacter nosocomialis clinical isolates (designated AC13, AC15, AC21 and AC25) obtained from Terengganu, Malaysia in 2011 to determine their genetic relatedness and basis of antimicrobial resistance. Methods: Antimicrobial susceptibility profiles of the A. nosocomialis isolates were determined by disk diffusion. Genome sequencing was performed using the Illumina NextSeq platform. Results: The four A. nosocomialis isolates were cefotaxime resistant whereas three isolates (namely, AC13, AC15 and AC25) were tetracycline resistant. The carriage of the blaADC-255-encoded cephalosporinase gene is likely responsible for cefotaxime resistance in all four isolates. Phylogenetic analysis indicated that the three tetracycline-resistant isolates were closely related, with an average nucleotide identity of 99.9%, suggestive of nosocomial spread, whereas AC21 had an average nucleotide identity of 97.9% when compared to these three isolates. The tetracycline-resistant isolates harboured two plasmids: a 13476 bp Rep3-family plasmid of the GR17 group designated pAC13-1, which encodes the tetA(39) tetracycline-resistance gene, and pAC13-2, a 4872 bp cryptic PriCT-1-family plasmid of a new Acinetobacter plasmid group, GR60. The tetA(39) gene was in a 2 001 bp fragment flanked by XerC/XerD recombination sites characteristic of a mobile pdif module. Both plasmids also harboured mobilisation/transfer-related genes. Conclusions: Genome sequencing of A. nosocomialis isolates led to the discovery of two novel plasmids, one of which encodes the tetA(39) tetracycline-resistant gene in a mobile pdif module. The high degree of genetic relatedness among the three tetracycline-resistant A. nosocomialis isolates is indicative of nosocomial transmission.

Conservation translocation and reintroduction for the purpose of repopulating and reinforcing extirpated or depleted populations has been recognised as an important conservation tool, particularly for gibbon conservation in the immediate future. Feasibility assessments involving multiple factors, including taxonomic and genetic assessment of rescued and captive gibbons, are imperative prior to translocation and reintroduction programmes. In this study, we attempt to determine the subspecies and origin of captive Hylobates lar, White-handed gibbons, from Peninsular Malaysia to assist in future translocation and reintroduction programmes. A total of 12 captive and rescued H. lar samples were analysed using the control region segment of mitochondrial DNA. Sequence analyses and phylogenetic trees constructed using neighbour-joining, maximum likelihood, Bayesian inference, and network methods congruently differentiate all 12 captive individuals used in this study from other H. lar subspecies suggesting that these individuals belong to the H. lar lar subspecies. In addition, two populations of H. l. lar were observed: (1) a southern population consisting of all 12 individuals from Peninsular Malaysia, and (2) a possible northern population represented by three individuals (from previous studies), which might have originated from the region between the Isthmus of Kra, Surat Thani-Krabi depression, and Kangar-Pattani. Our findings suggest that the complete control region segment can be used to determine the subspecies and origin of captive H. lar.

Mobile Banking has always been the focus of the banks to provide an alternative banking channel for the bank customers. However, the adoption rate was still relatively low and increased gradually over the decade. Thus, it is important to examine the factors affecting Mobile Banking Adoption to provide better insights to improve the situation for the bank customers to adopt it for banking purpose. In this conceptual article, the past literature related to the investigation of Technology Adoption was reviewed. Based on the review and also the understanding of the theory, this article further explores on the interactions of the constructs from Technology Acceptance Model (TAM) & Unified Theory of Acceptance and Use of Technology (UTAUT), Perceived Trust, Technology Awareness and Mobile Banking Adoption. With the study of these interactions, it is very likely to create new avenues for future research.

Background: A diagnosis of ankylosing spondylitis (AS) is challenging and often delayed despitebpatients being symptomatic. Low back pain is the most common initial symptom, appearing in the second and third decades of life. Acute anterior uveitis (AAU) occurs much later in the course of the disease, often when the destruction of the spine is already debilitating. Objective: Here, we report three cases of AS that were diagnosed after the patients developed AAU. Methods: A case series illustrated AAU leading to the diagnosis of AS years after the initial episode of low back pain. A comparison of the clinical presentation, diagnosis, and outcomes was also illustrated. Result: We report three cases of acute anterior uveitis (AAU)-associated AS diagnosed only after many visits to the primary health care provider with the complaint of chronic low back pain. All three patients had irreversible radiological changes upon diagnosis of AS. The AAU resolved with topical steroids, and one patient developed cataract. Conclusion: A high index of suspicion of AS in a young adult with chronic back pain before the development of AAU may prevent further functional loss and provide a better prognosis. Diagnosis of AS following AAU is not only associated with dependency but also may rob the vision of a young adult.

Methicillin-resistant Staphylococcus aureus (MRSA) is a priority nosocomial pathogen with plasmids playing a crucial role in its genetic adaptability, particularly in the acquisition and spread of antimicrobial resistance. In this study, the genome sequences of 79 MSRA clinical isolates from Terengganu, Malaysia, (obtained between 2016 and 2020) along with an additional 15 Malaysian MRSA genomes from GenBank were analyzed for their plasmid content. The majority (90%, 85/94) of the Malaysian MRSA isolates harbored 1–4 plasmids each. In total, 189 plasmid sequences were identified ranging in size from 2.3 kb to ca. 58 kb, spanning all seven distinctive plasmid replication initiator (replicase) types. Resistance genes (either to antimicrobials, heavy metals, and/or biocides) were found in 74% (140/189) of these plasmids. Small plasmids (ermC gene that confers resistance to macrolides, lincosamides, and streptogramin B (MLSB) identified in 63 MRSA isolates. A low carriage of conjugative plasmids was observed (n = 2), but the majority (64.5%, 122/189) of the non-conjugative plasmids have mobilizable potential. The results obtained enabled us to gain a rare view of the plasmidomic landscape of Malaysian MRSA isolates and reinforces their importance in the evolution of this pathogen.

Methicillin-resistant Staphylococcus aureus (MRSA) is a World Health Organization-listed priority pathogen. Scarce genomic data are available for MRSA isolates from Malaysia. Here, we present the complete genome sequence of a multidrug-resistant MRSA strain SauR3, isolated from the blood of a 6-year-old patient hospitalized in Terengganu, Malaysia, in 2016. S. aureus SauR3 was resistant to five antimicrobial classes comprising nine antibiotics. The genome was sequenced on the Illumina and Oxford Nanopore platforms and hybrid assembly was performed to obtain its complete genome sequence. The SauR3 genome consists of a circular chromosome of 2,800,017 bp and three plasmids designated pSauR3-1 (42,928 bp), pSauR3-2 (3011 bp), and pSauR3-3 (2473 bp). SauR3 belongs to sequence type 573 (ST573), a rarely reported sequence type of the staphylococcal clonal complex 1 (CC1) lineage, and harbors a variant of the staphylococcal cassette chromosome mec (SCCmec) type V (5C2&5) element which also contains the aac(6′)-aph(2″) aminoglycoside-resistance genes. pSauR3-1 harbors several antibiotic resistance genes in a 14,095 bp genomic island (GI), previously reported in the chromosome of other staphylococci. pSauR3-2 is cryptic, whereas pSauR3-3 encodes the ermC gene that mediates inducible resistance to macrolide-lincosamide-streptogramin B (iMLSB). The SauR3 genome can potentially be used as a reference genome for other ST573 isolates.

Multidrug resistance (MDR) is a significant challenge in healthcare management, and addressing it requires a comprehensive approach. In this study, we employed a combination of phenotypic and genotypic approaches, along with whole genome sequencing (WGS) to investigate five hospital-associated MDR methicillin-resistant Staphylococcus aureus (MRSA) strains that were isolated from newborn infants. Our analysis revealed the following for the MDR-MRSA strains: SauR31 was resistant to three antimicrobial classes; SauR12, SauR91 and SauR110 were resistant to four antimicrobial classes; and SauR23 exhibited resistance to seven classes. All the MDR-MRSA strains were capable of producing slime and biofilms, harbored SCCmec type IV, and belonged to different spa types (t022, t032, and t548), with varying profiles for microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) and virulence genes. The WGS data for the MDR SauR23 and SauR91 strains revealed that most of the antimicrobial resistance genes were present in the chromosomes, including blaZ, mecA, norA, lmrS, and sdrM, with only the ermC gene found in a small (

Abstract Much microbiome research has focused on populations that are predominantly of European descent, and from narrow demographics that do not capture the socio-economic and lifestyle differences which impact human health. Here we examined the airway microbiomes of the Orang Asli, the indigenous peoples of Malaysia. A total of 130 participants were recruited from two sites in the north-eastern state of Terengganu in Peninsular Malaysia. Using 16S rRNA sequencing, the nasal microbiome was significantly more diverse in those aged 5–17 years compared to 50+ years (p = 0.023) and clustered by age (PERMANOVA analysis of the Bray–Curtis distance, p = 0.001). Hierarchical clustering of Bray–Curtis dissimilarity scores revealed six microbiome clusters. The largest cluster (n = 28; 35.4%) had a marked abundance of Corynebacterium. In the oral microbiomes Streptococcus, Neisseria and Haemophilus were dominant. Using conventional microbiology, high levels of Staphylococcus aureus carriage were observed, particularly in the 18–65 age group (n = 17/36; 47.2% 95% CI: 30.9–63.5). The highest carriage of pneumococci was in the

Staphylococcus hominis is a coagulase-negative Staphylococcus (CoNS) commensal capable of causing serious systemic infections in humans. The emergence of multidrug-resistant S. hominis strains is of concern but little is known about the characteristics of this organism, particularly from Malaysia. Here, we present the comparative genome analysis of S. hominis ShoR14, a multidrug-resistant, methicillin-resistant blood isolate from Terengganu, Malaysia. Genomic DNA of S. hominis ShoR14 was sequenced on the Illumina platform and assembled using Unicycler v0.4.8. ShoR14 belonged to sequence type (ST) 1 which is the most prevalent ST of the S. hominis subsp. hominis. Comparative genomic analysis with closely related strains in the database with complete genome sequences, led to the discovery of a novel variant of the staphylococcal chromosome cassette mec (SCCmec) type VIII element harboring the mecA methicillin-resistance gene in ShoR14 and its possible carriage of a SCCfus element that encodes the fusidic acid resistance gene (fusC). Up to seven possible ShoR14 plasmid contigs were identified, three of which harbored resistance genes for tetracycline (tetK), chloramphenicol (catA7), macrolides, lincosamides, and streptogramin B (ermC). Additionally, we report the discovery of a novel mercury-resistant transposon, Tn7456, other genomic islands, and prophages which make up the S. hominis mobilome.

Objective: To evaluate the prevalence and divergence of genetically identified Leptospira spp. in the population of Rattus rattus. Methods: A total of 130 rats were used in this study. The infection within the rats were screened using polymerase chain reaction (PCR)-based diagnosis, with Leptospira genus-specific 16S rRNA primer and pathogenic Leptospira spp. specific LipL32 primer, on both kidney and liver tissues of Rattus rattus to detect the presence of potential Leptospira spp. Results: Out of 130 rats studied, 51 (39.23%) individuals were positive for leptospiral DNA. Basic Local Alignment Search Tool (BLAST) and phylogenetic analysis revealed that both pathogenic Leptospira interrogans and Leptospira borgpetersenii were predominantly identified. Phylogenetically, both genes disclosed similar clustering patterns of tree topologies between the two species. Although both genes were conserved, LipL32 gene portrayed higher nucleotide divergence (5.80%) compared to the 16S rRNA gene (0.60%). Minimum-spanning network displayed several haplotypes that are unique to each species, suggesting a higher degree of subdivision between both species. As for prevalence surveillance, both adult and subadult rats were susceptible to the infection, in which males were the most susceptible. Kidney was notable as the favourable organ for colonisation of leptospires. Rats captured from fresh markets were highly infected with Leptospira spp. (54.28%) compared to those from housing areas (26.47%). Conclusions: Rattus rattus represents an important asymptomatic transmitter of pathogenic leptospires, and hence is of public health concerns.

Background Staphylococcus aureus is one of the important pathogens causing nosocomial infection. spa typing allows identification of S. aureus clones in hospital isolates and is useful for epidemiological studies and nosocomial infection control. This study aims to investigate the spa types in Malaysian S. aureus isolates obtained from various clinical specimens. Method A total of 89 methicillin-resistant S. aureus (MRSA) [pus (n = 55), blood (n = 27), respiratory (n = 5), eye (n = 2)] isolates and 109 methicillin-susceptible S. aureus (MSSA) [pus (n = 79), blood (n = 24), respiratory (n = 3), eye (n = 2) and urine (n = 1)] isolates were subjected to spa typing with sequences analysed using BioNumerics version 7. Results The spa sequence was successfully amplified from 77.8% of the strains (154/198) and 47 known spa types were detected. The distribution of known spa types in MRSA (36.2%, 17/47) was less diverse than in MSSA (70.2%, 33/47). The most predominant spa types were t032 (50%) in MRSA, and t127 (19%) and t091 (16.7%) in MSSA, respectively. spa type t091 in MSSA was significantly associated with skin and soft tissue infections (p = 0.0199). Conclusion The previously uncommon spa type t032 was detected in the Malaysian MRSA strains, which also corresponded to the most common spa type in Europe and Australia, and has replaced the dominant spa type t037 which was reported in Malaysia in 2010.

Bacteria of the genus AcinetobacterA. baumanniiA. baumanniiA. nosocomialis

Elizabethkingia spp. is a ubiquitous pathogenic bacterium that has been identified as the causal agent for a variety of conditions such as meningitis, pneumonia, necrotizing fasciitis, endophthalmitis, and sepsis and is emerging as a global threat including in Southeast Asia. Elizabethkingia infections tend to be associated with high mortality rates (18.2–41%) and are mostly observed in neonates and immunocompromised patients. Difficulties in precisely identifying Elizabethkingia at the species level by traditional methods have hampered our understanding of this genus in human infections. In Southeast Asian countries, hospital outbreaks have usually been ascribed to E. meningoseptica, whereas in Singapore, E. anophelis was reported as the main Elizabethkingia spp. associated with hospital settings. Misidentification of Elizabethkingia spp. could, however, underestimate the number of cases attributed to the bacterium, as precise identification requires tools such as MALDI-TOF MS, and particularly whole-genome sequencing, which are not available in most hospital laboratories. Elizabethkingia spp. has an unusual antibiotic resistance pattern for a Gram-negative bacterium with a limited number of horizontal gene transfers, which suggests an intrinsic origin for its multidrug resistance. Efforts to prevent and further understand Elizabethkingia spp. infections and limit its spread must rise to this new challenge.

Background People with chronic heart failure (CHF) experience severe skeletal muscle dysfunction, characterized by mitochondrial abnormalities, which exacerbates the primary symptom of exercise intolerance. However, the molecular triggers and characteristics underlying mitochondrial abnormalities caused by CHF remain poorly understood. Methods and Results We recruited 28 patients with CHF caused by reduced ejection fraction and 9 controls. We simultaneously biopsied skeletal muscle from the pectoralis major in the upper limb and from the vastus lateralis in the lower limb. We phenotyped mitochondrial function in permeabilized myofibers from both sites and followed this by complete RNA sequencing to identify novel molecular abnormalities in CHF skeletal muscle. Patients with CHF presented with upper and lower limb skeletal muscle impairments to mitochondrial function that were of a similar deficit and indicative of a myopathy. Mitochondrial abnormalities were strongly correlated to symptoms. Further RNA sequencing revealed a unique transcriptome signature in CHF skeletal muscle characterized by a novel triad of differentially expressed genes related to deficits in energy metabolism including adenosine monophosphate deaminase 3, pyridine nucleotide‐disulphide oxidoreductase domain 2, and lactate dehydrogenase C. Conclusions Our data suggest an upper and lower limb metabolic myopathy that is characterized by a unique transcriptome signature in skeletal muscle of humans with CHF.

This paper presents the development of a real-time cloud-based in-vehicle air quality monitoring system that enables the prediction of the current and future cabin air quality. The designed system provides predictive analytics using machine learning algorithms that can measure the drivers’ drowsiness and fatigue based on the air quality presented in the cabin car. It consists of five sensors that measure the level of CO2, particulate matter, vehicle speed, temperature, and humidity. Data from these sensors were collected in real-time from the vehicle cabin and stored in the cloud database. A predictive model using multilayer perceptron, support vector regression, and linear regression was developed to analyze the data and predict the future condition of in-vehicle air quality. The performance of these models was evaluated using the Root Mean Square Error, Mean Squared Error, Mean Absolute Error, and coefficient of determination (R2). The results showed that the support vector regression achieved excellent performance with the highest linearity between the predicted and actual data with an R2 of 0.9981.

This study aimed to statistically compare preservice teachers’ assessment knowledge in crafting assessment task and selecting assessment method in relation to their teaching experience. This study involved 397 preservice teachers’ who were final year undergraduate students in a local university. The instrument of data collection consisted of eight superitems test. Data collected was analysed by using statistical method (SPSS version 22.0). The result showed that preservice teachers for all categories of teaching experience performed better in the selecting assessment method than crafting assessment task. However, there was no significant differences existed between the three categories of teaching experience of preservice teachers for both standards of assessment knowledge assessed.

Adsorption technology has led to the development of promising techniques to purify biogas, i.e., biomethane or biohydrogen. Such techniques mainly depend on the adsorbent ability and operating parameters. This research focused on adsorption technology for upgrading biogas technique by developing a novel adsorbent. The commercial coconut shell activated carbon (CAC) and two types of gases (H2S/N2 and H2S/N2/CO2) were used. CAC was modified by copper sulfate (CuSO4), zinc acetate (ZnAc2), potassium hydroxide (KOH), potassium iodide (KI), and sodium carbonate (Na2CO3) on their surface to increase the selectivity of H2S removal. Commercial H2S adsorbents were soaked in 7 wt.% of impregnated solution for 30 min before drying at 120°C for 24 h. The synthesized adsorbent's physical and chemical properties, including surface morphology, porosity, and structures, were characterized by SEM-EDX, FTIR, XRD, TGA, and BET analyses. For real applications, the modified adsorbents were used in a real-time 0.85 L single-column adsorber unit. The operating parameters for the H2S adsorption in the adsorber unit varied in L/D ratio (0.5-2.5) and feed flow rate (1.5-5.5 L/min) where, also equivalent with a gas hourly space velocity, GHSV (212.4-780.0 hour-1) used. The performances of H2S adsorption were then compared with those of the best adsorbent that can be used for further investigation. Characterization results revealed that the impregnated solution homogeneously covered the adsorbent surface, morphology, and properties (i.e., crystallinity and surface area). BET analysis further shows that the modified adsorbents surface area decreased by up to 96%. Hence, ZnAc2-CAC clarify as the best adsorption capacity ranging within 1.3-1.7 mg H2S/g, whereby the studied extended to adsorption-desorption cycle.

Portable polymer electrolyte membrane (PEM) fuel cell power generator is a PEM fuel cell application that is used as an external charger to supply the demand for high energy. Different environments at various ambient temperatures and humidity levels affect the performance of PEM fuel cell power generators. Thermal and water management in portable PEM fuel cells are a critical technical barrier for the commercialization of this technology. The size and weight of the portable PEM fuel cells used for thermal and water management systems that determine the performance of portable PEM fuel cells also need to be considered. The main objective of this paper review was to determine the importance of water and thermal management systems in portable PEM fuel cells. Additionally, this review investigated heat transfer and water transport in PEM fuel cells. Given that portable PEM fuel cells with different powers require different thermal and water management systems, this review also discussed and compared management systems for low-, medium-, and high-power portable PEM fuel cells.

The majority of deaths due to Streptococcus pneumoniae infections are in developing countries. Although polysaccharide-based pneumococcal vaccines are available, newer types of vaccines are needed to increase vaccine affordability, particularly in developing countries, and to provide broader protection across all pneumococcal serotypes. To attenuate pneumococcal virulence with the aim of engineering candidate live attenuated vaccines (LAVs), we constructed knockouts in S. pneumoniae D39 of one of the capsular biosynthetic genes, cpsE that encodes glycosyltransferase, and the endonuclease gene, endA, that had been implicated in the uptake of DNA from the environment as well as bacterial escape from neutrophil-mediated killing. The cpsE gene knockout significantly lowered peak bacterial density, BALB/c mice nasopharyngeal (NP) colonisation but increased biofilm formation when compared to the wild-type D39 strain as well as the endA gene knockout mutant. All constructed mutant strains were able to induce significantly high serum and mucosal antibody response in BALB/c mice. However, the cpsE-endA double mutant strain, designated SPEC, was able to protect mice from high dose mucosal challenge of the D39 wild-type. Furthermore, SPEC showed 23-fold attenuation of virulence compared to the wild-type. Thus, the cpsE-endA double-mutant strain could be a promising candidate for further development of a LAV for S. pneumoniae.

The consumption of coconut milk has long been regarded as detrimental to cardiovascular health due to its high saturated fatty acid content. Contradictorily, emerging evidences have highlighted that the fatty acids in coconut lipids, which comprise mostly of medium-chain fatty acids (MCFA), may be beneficial to the regulation of serum cholesterol. To identify the potential health effect of coconut milk on lipid metabolism, this current study employed an intragastric gavage method on C57BL/6 mice to investigate the physiological and molecular alteration in the mice subject after 8 weeks of gavage intervention. The supplementation of coconut milk did not affect the levels of serum triglyceride, but it induced the total serum cholesterol after 2 weeks of treatment. The serum cholesterol level subsequently plateaued, but an increase in bile acid excretion was observed, most likely through the modulation of bile regulating genes, i.e. farnesoid X receptor (Fxr) and Cyp7a1. Despite that, the total cholesterol to HDL cholesterol ratio of coconut milk group was comparable to that of the light cream group. In short, coconut milk supplementation promoted cholesterol excretion through the fecal bile route but did not significantly improve the serum cholesterol profile of C57BL/6 mice.

Acinetobacter spp. are important nosocomial pathogens, in particular the Acinetobacter baumannii-calcoaceticus complex, which have become a global public health threat due to increasing resistance to carbapenems and almost all other antimicrobial compounds. High rates of resistance have been reported among countries in Southeast Asia, including Malaysia. In this review, we examine the antimicrobial resistance profiles of Acinetobacter spp. hospital isolates from Malaysia over a period of nearly three decades (1987–2016) with data obtained from various peer-reviewed publications as well as the Malaysian National Surveillance on Antibiotic Resistance (NSAR). NSAR data indicated that for most antimicrobial compounds, including carbapenems, the peak resistance rates were reached around 2008–2009 and thereafter, rates have remained fairly constant (e.g., 50–60% for carbapenems). Individual reports from various hospitals in Peninsular Malaysia do not always reflect the nationwide resistance rates and often showed higher rates of resistance. We also reviewed the epidemiology and mechanisms of resistance that have been investigated in Malaysian Acinetobacter spp. isolates, particularly carbapenem resistance and found that blaOXA-23 is the most prevalent acquired carbapenemase-encoding gene. From the very few published reports and whole genome sequences that are available, most of the Acinetobacter spp. isolates from Malaysia belonged to the Global Clone 2 (GC2) CC92 group with ST195 being the predominant sequence type. The quality of data and analysis in the national surveillance reports could be improved and more molecular epidemiology and genomics studies need to be carried out for further in-depth understanding of Malaysian Acinetobacter spp. isolates.

Purpose – This qualitative study explores if there were any changes in teachers’ reflection in terms of content and levels after participating in five lesson study cycles. Method – Case study method was employed in this study. Six mathematics teachers from a primary school participated in this study. They set up a lesson study group and conducted five lesson study cycles. In each lesson study cycle, the lesson study team members plan, teach and observe a research lesson. Qualitative data was collected through participatory observation, reflection sessions, collection of artefacts and interviews. Findings – Analysis of data revealed that there were some slight and slow changes in the teachers’ reflection as they progressed from the first to the fifth reflection sessions. These changes included: (1) teachers’ reflection became more specific and in-depth; (2) teachers’ reflection about the pupils’ learning became more in-depth; (3) teachers reflected from pupils’ perspectives; and (4) teachers reflect athigher level of reflection. Significance – The study revealed that the criteria of lesson study, collaborative and classroom observation, made it feasible in promoting teachers’ reflection. The educators could employ lesson study as an approach to promote teachers’ reflection. However, the effectiveness of lesson study in promoting teachers’ reflection is 146 Malaysian Journal of Learning and Instruction: Special Issues 2017: 145-172 affected by the number of lesson study cycles being carried out and the presence of the knowledgeable others.

Acinetobacter baumannii is a Gram-negative nosocomial pathogen that has become a serious healthcare concern within a span of two decades due to its ability to rapidly acquire resistance to all classes of antimicrobial compounds. One of the key features of the A. baumannii genome is an open pan genome with a plethora of plasmids, transposons, integrons, and genomic islands, all of which play important roles in the evolution and success of this clinical pathogen, particularly in the acquisition of multidrug resistance determinants. An interesting genetic feature seen in majority of A. baumannii genomes analyzed is the presence of small plasmids that usually ranged from 2 to 10 kb in size, some of which harbor antibiotic resistance genes and homologs of plasmid mobilization genes. These plasmids are often overlooked when compared to their larger, conjugative counterparts that harbor multiple antibiotic resistance genes and transposable elements. In this mini-review, we will examine our current knowledge of these small A. baumannii plasmids and look into their genetic diversity and phylogenetic relationships. Some of these plasmids, such as the Rep-3 superfamily group and the pRAY-type, which has no recognizable replicase genes, are quite widespread among diverse A. baumannii clinical isolates worldwide, hinting at their usefulness to the lifestyle of this pathogen. Other small plasmids especially those from the Rep-1 superfamily are truly enigmatic, encoding only hypothetical proteins of unknown function, leading to the question of whether these small plasmids are “good” or “bad” to their host A. baumannii.

Toxin–antitoxin (TA) genes were first reported in plasmids and were considered expendable genetic cassettes involved in the stable maintenance of the plasmid replicon by interfering with growth and/or viability of bacteria in which the plasmid was lost. TAs were later found in bacterial chromosomes and also in integrated mobile genetic elements; they were proposed to be involved in the bacterial response to stressful situations. At present, 100s of TAs have been identified and classified in up to six families (I to VI), with those belonging to the type II (constituted by two protein components) being the most studied. Based on well-characterized examples of several type II TAs, we discuss in this review that irrespective of their locations in plasmids or chromosomes, TAs functionally overlap as indicated by: (i) in both locations they can mediate the maintenance of genetic elements to which they are physical linked, and (ii) they can induce persistence or virulence in response to stress situations. Examples of functional confluences in homologous TA systems with different locations are also given. We also consider whether the physiological role of TAs is due to their genetic organization as operons or to their inherent properties, like the short lifespan of the antitoxin component.

Thin liquid films are central to everyday life. They are ubiquitous in modern technology (pharmaceuticals, coatings), consumer products (foams, emulsions) and also serve vital biological functions (tear film of the eye, pulmonary surfactants in the lung). A common feature in all these examples is the presence of surface-active molecules at the air-liquid interface. Though they form only molecular-thin layers, these surfactants produce complex surface stresses on the free surface, which have important consequences for the dynamics and stability of the underlying thin liquid film. Here we conduct simple thinning experiments to explore the fundamental mechanisms that allow the surfactant molecules to slow the gravity-driven drainage of the underlying film. We present a simple model that works for both soluble and insoluble surfactant systems in the limit of negligible adsorption-desorption dynamics. We show that surfactants with finite surface rheology influence bulk flow through viscoelastic interfacial stresses, while surfactants with inviscid surfaces achieve stability through opposing surface-tension induced Marangoni flows.

Staphylococcus aureus is an important nosocomial pathogen and its multidrug resistant strains, particularly methicillin-resistant S. aureus (MRSA), poses a serious threat to public health due to its limited therapeutic options. The increasing MRSA resistance towards vancomycin, which is the current drug of last resort, gives a great challenge to the treatment and management of MRSA infections. While vancomycin resistance among Malaysian MRSA isolates has yet to be documented, a case of vancomycin resistant S. aureus has been reported in our neighboring country, Indonesia. In this review, we present the antimicrobial resistance profiles of S. aureus clinical isolates in Malaysia with data obtained from the Malaysian National Surveillance on Antimicrobial Resistance (NSAR) reports as well as various peer-reviewed published records spanning a period of nearly three decades (1990−2017). We also review the clonal types and characteristics of Malaysian S. aureus isolates, where hospital-associated (HA) MRSA isolates tend to carry staphylococcal cassette chromosome mec (SCCmec) type III and were of sequence type (ST)239, whereas community-associated (CA) isolates are mostly SCCmec type IV/V and ST30. More comprehensive surveillance data that include molecular epidemiological data would enable further in-depth understanding of Malaysian S. aureus isolates.

Upstream oil production using dual string completion, i.e., two tubing inside a well casing, is common due to its cost advantage. High pressure gas is employed to lift the oil to the surface when there is insufficient reservoir energy to overcome the liquids static head in the tubing. However, gas lifting for this type of completion can be complicated. This is due to the operating condition where total gas is injected into the common annulus and then allowed to be distributed among the two strings without any surface control. High uncertainties often result from the methods used to determine the split factor—the ratio between the gas lift rate to one string over the total gas injected. A hybrid model which combined three platforms: the Visual Basics for Application programme, PROSPER (a nodal analysis tool) and Excel spreadsheet, is proposed for the estimation of the split factor. The model takes into consideration two important parameters, i.e., the lift gas pressure gradient along the annulus and the multiphase pressure drop inside the tubing to estimate the gas lift rate to the individual string and subsequently the split factor. The proposed model is able to predict the split factor to within 2% to 7% accuracy from the field measured data. Accurate knowledge of the amount of gas injected into each string leads to a more efficient use of lift gas, improving the energy efficiency of the oil productions facilities and contributing toward the sustainability of fossil fuel.

In their initial stages of discovery, prokaryotic toxin-antitoxin (TA) systems were confined to bacterial plasmids where they function to mediate the maintenance and stability of usually low- to medium-copy number plasmids through the post-segregational killing of any plasmid-free daughter cells that developed. Their eventual discovery as nearly ubiquitous and repetitive elements in bacterial chromosomes led to a wealth of knowledge and scientific debate as to their diversity and functionality in the prokaryotic lifestyle. Currently categorized into six different types designated types I – VI, type II TA systems are the best characterized. These generally comprised of two genes encoding a proteic toxin and its corresponding proteic antitoxin, respectively. Under normal growth conditions, the stable toxin is prevented from exerting its lethal effect through tight binding with the less stable antitoxin partner, forming a non-lethal TA protein complex. Besides binding with its cognate toxin, the antitoxin also plays a role in regulating the expression of the type II TA operon by binding to the operator site, thereby repressing transcription from the TA promoter. In most cases, full repression is observed in the presence of the TA complex as binding of the toxin enhances the DNA binding capability of the antitoxin. TA systems have been implicated in a gamut of prokaryotic cellular functions such as being mediators of programmed cell death as well as persistence or dormancy, biofilm formation, as defensive weapons against bacteriophage infections and as virulence factors in pathogenic bacteria. It is thus apparent that these antitoxins, as DNA-binding proteins, play an essential role in modulating the prokaryotic lifestyle whilst at the same time preventing the lethal action of the toxins under normal growth conditions, i.e., keeping the proverbial wolves at bay. In this review, we will cover the diversity and characteristics of various type II TA antitoxins. We shall also look into some interesting deviations from the canonical type II TA systems such as tripartite TA systems where the regulatory role is played by a third party protein and not the antitoxin, and a unique TA system encoding a single protein with both toxin as well as antitoxin domains.

Acinetobacter baumannii is a Gram-negative nosocomial pathogen of importance due to its uncanny ability to acquire resistance to most antimicrobials. These include carbapenems, which are the drugs of choice for treating A. baumannii infections, and polymyxins, the drugs of last resort. Whole genome sequencing was performed on two clinical carbapenem-resistant A. baumannii AC29 and AC30 strains which had an indistinguishable ApaI pulsotype but different susceptibilities to polymyxin. Both genomes consisted of an approximately 3.8 Mbp circular chromosome each and several plasmids. AC29 (susceptible to polymyxin) and AC30 (resistant to polymyxin) belonged to the ST195 lineage and are phylogenetically clustered under the International Clone III (IC-III) group. An AbaR4-type resistance island (RI) interrupted the comM gene in the chromosomes of both strains and contained the blaOXA-23 carbapenemase gene and determinants for tetracycline and streptomycin resistance. AC29 harboured another copy of blaOXA-23 in a large (~74 kb) conjugative plasmid, pAC29b, but this gene was absent in a similar plasmid (pAC30c) found in AC30. A 7 kb Tn1548::armA RI which encodes determinants for aminoglycoside and macrolide resistance, is chromosomally-located in AC29 but found in a 16 kb plasmid in AC30, pAC30b. Analysis of known determinants for polymyxin resistance in AC30 showed mutations in the pmrA gene encoding the response regulator of the two-component pmrAB signal transduction system as well as in the lpxD, lpxC and lpsB genes that encode enzymes involved in the biosynthesis of lipopolysaccharide (LPS). Experimental evidence indicated that impairment of LPS along with overexpression of pmrAB may have contributed to the development of polymyxin resistance in AC30. Cloning of a novel variant of the blaAmpC gene from AC29 and AC30, and its subsequent expression in E. coli also indicated its likely function as an extended-spectrum cephalosporinase

Extraintestinal pathogenic Escherichia coli (ExPEC) that causes extraintestinal infections often harbor plasmids encoding fitness traits such as resistance and virulence determinants that are of clinical importance. We determined the complete nucleotide sequence of plasmid pEC302/04 from a multidrug-resistant E. coli EC302/04 which was isolated from the tracheal aspirate of a patient in Malaysia. In addition, we also performed comparative sequence analyses of 18 related IncFIIA plasmids to determine the phylogenetic relationship and diversity of these plasmids. The 140,232 bp pEC302/04 is a multireplicon plasmid that bears three replication systems (FII, FIA and FIB) with subtype of F2:A1:B1. The plasmid is self-transmissible with a complete transfer region. pEC302/04 also carries antibiotic resistance genes such as blaTEM-1 and a class I integron containing sul1, cml and aadA resistance genes, conferring multidrug resistance (MDR) to its host, E. coli EC302/04. Besides, two iron acquisition systems (SitABCD and IutA-IucABCD) which are the conserved virulence determinants of ExPEC-colicin V or B and M (ColV/ColBM)-producing plasmids were identified in pEC302/04. Multiple toxin-antitoxin (TA)-based addiction systems (i.e., PemI/PemK, VagC/VagD, CcdA/CcdB, and Hok/Sok) and a plasmid partitioning system, ParAB and PsiAB, which are important for plasmid maintenance were also found.Comparative plasmid analysis revealed only one conserved gene, the repA1 as the core genome, showing that there is an extensive diversity among the IncFIIA plasmids. The phylogenetic relationship of 18 IncF plasmids based on the core regions revealed that ColV/ColBM-plasmids and non-ColV/ColBM plasmids were separated into two distinct groups. These plasmids, which carry highly diverse genetic contents, are also mosaic in nature. The atypical combination of genetic materials, i.e., the MDR- and ColV/ColBM-plasmid-virulence encoding regions in a single ExPEC plasmid is rare but of clinical importance. Such phenomenon is bothersome when the plasmids are transmissible, facilitating the spread of virulence and resistance plasmids among pathogenic bacteria. Notably, certain TA systems are more commonly found in particular ExPEC plasmid types, indicating the possible relationships between certain TA systems and ExPEC pathogenesis.

Bacterial toxin-antitoxin (TAs) loci usually consist of two genes organized as an operon, where their products are bound together and inert under normal conditions. However, under stressful circumstances the antitoxin, which is more labile, will be degraded more rapidly, thereby unleashing its cognate toxin to act on the cell. This, in turn, causes cell stasis or cell death, depending on the type of TAs and/or time of toxin exposure. Previously based on in silico analyses, we proposed that Streptococcus pneumoniae, a pathogenic Gram-positive bacterium, may harbor between four to ten putative TA loci depending on the strains. Here we have chosen the pneumococcal strain Hungary19A-6 which contains all possible ten TA loci. In addition to the three well-characterized operons, namely relBE2, yefM-yoeB, and pezAT, we show here the functionality of a fourth operon that encodes the pneumococcal equivalent of the phd-doc TA. Transcriptional fusions with gene encoding Green Fluorescent Protein showed that the promoter was slightly repressed by the Phd antitoxin, and exhibited almost background values when both Phd-Doc were expressed together. These findings demonstrate that phd-doc shows the negative self-regulatory features typical for an authentic TA. Further, we also show that the previously proposed TAs XreA-Ant and Bro-XreB, although they exhibit a genetic organization resembling those of typical TAs, did not appear to confer a functional behavior corresponding to bona fide TAs. In addition, we have also discovered new interesting bioinformatics results for the known pneumococcal TAs RelBE2 and PezAT. A global analysis of the four identified toxins-antitoxins in the pneumococcal genomes (PezAT, RelBE2, YefM-YoeB, and Phd-Doc) showed that RelBE2 and Phd-Doc are the most conserved ones. Further, there was good correlation among TA types, clonal complexes and sequence types in the 48 pneumococcal strains analyzed.

Most of the efforts in elucidating the molecular relatedness and epidemiology of Staphylococcus aureus in Malaysia have been largely focused on methicillin-resistant S. aureus (MRSA). Therefore, here we report the draft genome sequence of the methicillin-susceptible Staphylococcus aureus (MSSA) with sequence type 1 (ST1), spa type t127 with Panton-Valentine Leukocidin (pvl) pathogenic determinant isolated from pus sample designated as KT/314250 strain. The size of the draft genome is 2.86 Mbp with 32.7% of G + C content consisting 2673 coding sequences. The draft genome sequence has been deposited in DDBJ/EMBL/GenBank under the accession number AOCP00000000.

A cholera outbreak in Terengganu, Malaysia, in November 2009 was caused by 2 El Tor Vibrio cholerae variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures.

This study aimed to investigate the survival of Vibrio cholerae O1 in 3 types of preparation for cooked rice, Oryza sativa L., (plain rice, rice with coconut milk, and rice with ginger); coffee, Coffea canephora, (plain coffee, coffee with sugar, and coffee with sweetened condensed milk); and tea, Camellia sinensis, (plain tea, tea with sugar, and tea with sweetened condensed milk) held at room temperature (27°C). The survival of V. cholerae O1 was determined by spread plate method on TCBS agar. Initial cultures of 8.00 log CFU/mL were inoculated into each food sample. After 6 h incubation, significant growth was only detected in rice with coconut milk (9.67 log CFU/mL; P