Search

Aim: To determine the prevalence of group B Streptococcus (GBS) carriage among parturient women and neonates, and the relative risk of vertical transmission, the relative risk of early and late‐onset GBS and the pooled incidence of early‐late‐onset GBS infection. Methods: A systematic search of relevant cohort studies from three electronic databases to identify all relevant studies published up to 7 November 2022. The review was conducted in accordance with PRISMA guidelines. Estimates were pooled using random‐effects meta‐analyses. Results: A total of 54 articles with 355 787 matched pairs of parturient women and neonates from 30 countries were included in the analysis. The pooled prevalence of GBS colonisation was 17.1% among the pregnant women and 1.0% among neonates. The pooled prevalence of vertical transmission of GBS was 4.5% and the pooled relative risk of GBS colonisation of neonates born to mothers with GBS was 9.9. Conclusion: We support the implementation of targeted intrapartum antibiotic prophylaxis for all women who are positive for GBS as well as women with risks factors for early onset GBS in their infants regardless of their GBS colonisation status. [ABSTRACT FROM AUTHOR]

Objective: To assess the efficacy of various types of vaccines developed for leptospirosis. Methods: A comprehensive search was conducted in three databases: PubMed, Scopus, and Cochrane Library. Two authors (YS and MN) selected the articles based on manual screening. The study eligibility criteria are all Leptospira species regardless of any cluster (pathogenic, intermediate and non-pathogenic). This study recorded articles with positive and negative results and showed a comparison among various membrane proteins as vaccine candidates. The studies on the effectiveness of outer membrane protein as vaccine candidates were also included. The articles obtained in the databases were imported into the WPS spreadsheet, and duplicate documents were removed manually. Results: A total of 24 studies were included in the review, which evaluated various types of leptospirosis vaccines. Multiple vaccines were developed and tested; however, the heterogeneity of Leptospira species pose a challenge. As an effective approach, an epitope based vaccine shows quite a promising result. However, sufficient validation, testing and clinical trials are required. Conclusions: Developing an effective vaccine for leptospirosis remains a global health priority. While significant progress has been made in recent years, there is a need for further research to optimize vaccine development and to ensure that vaccines are accessible and effective for high-risk populations. [ABSTRACT FROM AUTHOR]

This study is based on the premise of investigating antibacterial activity through a novel conjugate of silver nanoparticles (AgNPs) and antimicrobial peptides (AMPs) in line with a green synthesis approach by developing antimicrobial-coated implants to prevent bacterial resistance. The AMPs were obtained from Bellamya Bengalensis (BB), a freshwater snail, to prepare the nanocomposite conjugate, e.g., AgNPs@BB extract, by making use of UV-Visible spectroscopy. The antimicrobial assessment of AgNPs@BB extract conjugate was performed using the Resazurin Microtiter Assay Method (REMA), followed by the use of three biocompatible implant materials (titanium alloys, Ti 6AL-4V stainless steel 316L, and polyethylene). Finally, the coating was analyzed under confocal microscopy. The results revealed a significant reduction of biofilm formation on the surfaces of implants coated with conjugate (AgNPs@BB extract) in comparison to uncoated implants. For the MTT assay, no significant changes were recorded for the cells grown on the AgNPs/AMP++ sample in high concentrations. Staphylococcus epidermidis, however, showed more prominent growth on all implants in comparison to Staphylococcus aureus. It is evident from the results that Staphylococcus epidermidis is more susceptible to AgNPs@BB extract, while the minimum inhibitory concentration (MIC) value of AgNPs@BB extract conjugates and biosynthesized AgNPs was also on the higher side. This study indicates that AgNPs@BB extract carries antibacterial activity, and concludes that an excessive concentration of AgNPs@BB extract may affect the improved biocompatibility. This study recommends using robust, retentive, and antimicrobial coatings of AgNPs@BB extract for implantable biocompatible materials in accordance with the novel strategy of biomaterial applications. [ABSTRACT FROM AUTHOR]

Introduction: The emergence of a novel Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a pandemic. Rapid and accurate diagnosis method is crucial to reduce the disease burden and to improve early diagnosis approaches to control of the disease. Real time Reverse transcriptase PCR (qRT-PCR) has been identified by the World Health Organization as the most sensitive and specific method of detection. However, the success of this assay relies on the quantity and quality of the extracted viral RNA. Methods: Various methods have been developed for nucleic acid extraction however, the methods have not been assessed. RNA extraction was performed from 24 nasopharyngeal swab samples using a manual extraction kit (GF-1) and an automated extraction kit (Genolution). The concentration and purity of the extracted RNA samples were measured, and its performance were tested using qRT-PCR. Results: The average concentration and purity of the RNA samples extracted using GF-1 kit was higher compared to Genolution. Similarly, the qRT-PCR assay using the RNA samples extracted using manual extraction was better compared to automated kit. Conclusion: Both the manual and automated extraction kits have its advantages and disadvantages in terms of yield and purity. However, with proper optimization, both methods may be used for routine molecular diagnostic of COVID-19 in laboratories. [ABSTRACT FROM AUTHOR]

Introduction: Continuous ambulatory peritoneal dialysis (CAPD)-associated peritonitis remains a major complication in patients on CAPD leading to increased morbidity and mortality. Successful therapy of peritonitis is highly dependent on a positive microbiological culture because narrow spectrum antibiotics are essential to efficiently combat infection. Therefore, this study evaluated the performance of Tween 80 containing media at three different concentrations (0.1%, 1.0% and 2.0%) to increase the pathogen yield from peritoneal fluid in comparison with the standard culture media. Materials and methods: Peritoneal fluid samples (n=121) obtained from CAPD patients suspected of peritonitis at Hospital Kuala Lumpur were analysed macroscopically and microscopically prior to culture. All samples were cultured on seven different culture media, including sheep blood agar, MacConkey agar, Sabouraud dextrose agar, brain heart infusion agar and Tween 80 incorporated blood agar. All plates were incubated at an optimum temperature up to 48 hours. Results and conclusion: Among all the culture media investigated, 0.1% to 2.0% Tween 80 incorporated blood agar yielded the highest positive culture (23/121) in comparison with all other standard media, thus lowering the negative culture rate among CAPD patients. Statistical analysis by Chi Square revealed significant differences (p <0.001) between the three concentrations of Tween 80 tested in this study. Among the three different concentrations of Tween 80 optimised in this study, blood agar containing 0.1% Tween 80 generated the best results, achieved by optimum growth of all Gram-positive organisms, Gram-negative organisms and yeast cells simultaneously. Using a small amount of detergent at low cost significantly increased the pathogen yield during CAPD-associated peritonitis. [ABSTRACT FROM AUTHOR]

Background and Objectives: Matrix metalloproteinases (MMP) have been implicated as major determinants of tumour growth and metastasis, which are considered two of the main hallmarks of cancer. The interaction of MMP8 and other signalling molecules within and adjacent tumoral tissues, including immune cells, are rather elusive, particularly of adenocarcinoma cell type. In this study, we aimed to investigate the role of MMP8 in non-small cell lung cancer proliferation and invasiveness potential. Materials and Methods: We individually lipofected with two different single guide RNA (sgRNAs) that specifically targeted on MMP8, with CRISPR-Cas 9 protein into the cells. Results: Our results clearly indicated that the lipofection of these complexes could lead to reduced ability of A549 cells to survive and proliferate to form colonies. In addition, when compared to non-transfected cells, the experimental cell groups receiving sgRNAs demonstrated relatively decreased migration rate, hence, wider wound gaps in scratch assay. The quantitative real time-polymerase chain reaction (qRT-PCR) demonstrated significant reduction in the MAP-K, survivin and PI3-K gene expression. MMP8 might have protective roles over tumour growth and spread in our body. Conclusions: The delivery of sgRNAs targeting on the MMP8 gene could induce tumour cell death and arrest cell migratory activity. [ABSTRACT FROM AUTHOR]

Childhood obesity is a serious public health problem worldwide. Perturbations in the gut microbiota composition have been associated with the development of obesity in both children and adults. Probiotics, on the other hand, are proven to restore the composition of the gut microbiome which helps reduce the development of obesity. However, data on the effect of probiotics on gut microbiota and its association with childhood obesity is limited. This study aims to determine the effect of probiotics supplement intervention on gut microbiota profiles in obese and normal-weight children. A total of 37 children, 17 normal weight, and 20 overweight school children from a government school in Selangor were selected to participate in this study. Participants were further divided into intervention and control groups. The intervention groups received daily probiotic drinks while the control groups continued eating their typical diet. Fecal samples were collected from the participants for DNA extraction. The hypervariable V3 and V4 regions of 16S rRNA gene were amplified and sequenced using the Illumina MiSeq platform. No significant differences in alpha diversity were observed between normal weight and obese children in terms of the Shannon Index for evenness or species richness. However, a higher intervention effect on alpha diversity was observed among normal-weight participants compared to obese. The participants' microbiome was found to fluctuate throughout the study. Analysis of the taxa at species level showed an increase in Bacteroides ovatus among the normal weight cohort. Genus-level comparison revealed a rise in genus Lachnospira and Ruminococcus in the overweight participants after intervention, compared to the normal-weight participants. The probiotics intervention causes an alteration in gut microbiota composition in both normal and overweight children. Though the association could not be defined statistically, this study has provided an improved understanding of the intervention effect of probiotics on gut microbiome dysbiosis in an underrepresented population. [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia is a multi-drug-resistant global opportunistic nosocomial pathogen, which possesses a huge number of virulence factors and antibiotics resistance characteristics. Iron has a crucial contribution toward growth and development, cell growth and proliferation, and pathogenicity. The bacterium found to acquire iron for its cellular process through the expression of two iron acquisition systems. Two distinct pathways for iron acquisition are encoded by the S. maltophilia genome-a siderophore-and heme-mediated iron uptake system. The entAFDBEC operon directs the production of the enterobactin siderophore of catecholate in nature, while heme uptake relies on hgbBC and potentially hmuRSTUV operon. Fur and sigma factors are regulators of S. maltophilia under iron-limited condition. Iron potentially act as a signal which plays an important role in biofilm formation, extracellular polymeric substances (EPS), extracellular enzymes production, oxidative stress response, diffusible signal factor (DSF) and siderophore production in S. maltophilia. This review summarizes the current knowledge of iron acquisition in S. maltophilia and the critical role of iron in relation to its pathogenicity. [ABSTRACT FROM AUTHOR]

The matrix (M) protein of Nipah virus (NiV) is a peripheral protein that plays a vital role in the envelopment of nucleocapsid protein and acts as a bridge between the viral surface and the nucleocapsid proteins. The M protein is also proven to play an important role in production of virus-like particles (VLPs) and is essential for assembly and budding of NiV particles. The recombinant M protein produced in Escherichia coli assembled into VLPs in the absence of the viral surface proteins. However, the E. coli produced VLPs are smaller than the native virus particles. Therefore, the aims of this study were to produce NiV M protein in Pichia pastoris, to examine the structure of the VLPs formed, and to assess the potential of the VLPs as a diagnostic reagent. The M protein was successfully expressed in P. pastoris and was detected with anti-myc antibody using Western blotting. The VLPs formed by the recombinant M protein were purified with sucrose density gradient ultracentrifugation, high-performance liquid chromatography (HPLC), and Immobilized Metal Affinity Chromatography (IMAC). Immunogold staining and transmission electron microscopy confirmed that the M protein assembled into VLPs as large as 200 nm. ELISA revealed that the NiV M protein produced in P. pastoris reacted strongly with positive NiV sera demonstrating its potential as a diagnostic reagent. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1038-1045, 2016 [ABSTRACT FROM AUTHOR]

The biosynthesis of silver nanoparticles and the antibacterial activities has provided enormous data on populations, geographical areas, and experiments with bio silver nanoparticles' antibacterial operation. Several peer-reviewed publications have discussed various aspects of this subject field over the last generation. However, there is an absence of a detailed and structured framework that can represent the research domain on this topic. This paper attempts to evaluate current articles mainly on the biosynthesis of nanoparticles or antibacterial activities utilizing the scientific methodology of big data analytics. A comprehensive study was done using multiple databases—Medline, Scopus, and Web of Sciences through PRISMA (i.e., Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The keywords used included 'biosynthesis silver nano particles' OR 'silver nanoparticles' OR 'biosynthesis' AND 'antibacterial behavior' OR 'anti-microbial opposition' AND 'systematic analysis,' by using MeSH (Medical Subject Headings) terms, Boolean operator's parenthesis, or truncations as required. Since their effectiveness is dependent on particle size or initial concentration, it necessitates more research. Understanding the field of silver nanoparticle biosynthesis and antibacterial activity in Gulf areas and most Asian countries also necessitates its use of human-generated data. Furthermore, the need for this work has been highlighted by the lack of predictive modeling in this field and a need to combine specific domain expertise. Studies eligible for such a review were determined by certain inclusion and exclusion criteria. This study contributes to the existence of theoretical and analytical studies in this domain. After testing as per inclusion criteria, seven in vitro studies were selected out of 28 studies. Findings reveal that silver nanoparticles have different degrees of antimicrobial activity based on numerous factors. Limitations of the study include studies with low to moderate risks of bias and antimicrobial effects of silver nanoparticles. The study also reveals the possible use of silver nanoparticles as antibacterial irrigants using various methods, including a qualitative evaluation of knowledge and a comprehensive collection and interpretation of scientific studies. [ABSTRACT FROM AUTHOR]

Leptospirosis is one of the most widespread bacterial diseases caused by pathogenic Leptospira. There are broad clinical manifestations due to varied pathogenicity of Leptospira spp., which can be classified into three clusters such as pathogenic, intermediate, and saprophytic. Intermediate Leptospira spp. can either be pathogenic or non-pathogenic and they have been reported to cause mild to severe forms of leptospirosis in several studies, contributing to the disease burden. Hence, this study aimed to estimate the global prevalence of intermediate Leptospira spp. in humans using meta-analysis with region-wise stratification. The articles were searched from three databases which include PubMed, Scopus, and ScienceDirect. Seven studies were included consisting of two regions based on United Nations geo-scheme regions, among 469 records identified. Statistical analysis was performed using RevMan software. The overall prevalence estimate of intermediate Leptospira spp. in humans was 86% and the pooled prevalences were 96% and 17% for the American and Asia regions, respectively. The data also revealed that Leptospira wolffii was the most predominantly found compared to the other intermediate species identified from the included studies, which were Leptospira inadai and Leptospira broomii. The estimated prevalence data from this study could be used to develop better control and intervention strategies in combating human leptospirosis. [ABSTRACT FROM AUTHOR]

Allium sativum (garlic) is widely known and is consumed as a natural prophylactic worldwide. It produces more than 200 identified chemical compounds, with more than 20 different kinds of sulfide compounds. The sulfide compounds particularly are proven to contribute to its various biological roles and pharmacological properties such as antimicrobial, antithrombotic, hypoglycemic, antitumour, and hypolipidemic. Therefore, it is often referred as disease-preventive food. Sulphur-containing compounds from A. sativum are derivatives of S-alkenyl-l-cysteine sulfoxides, ajoene molecules, thiosulfinates, sulfides, and S-allylcysteine. This review presents an overview of the water-soluble and oil-soluble sulphur based phytochemical compounds present in garlic, highlighting their mechanism of action in treating various health conditions. However, its role as a therapeutic agent should be extensively studied as it depends on factors such as the effective dosage and the suitable method of preparation. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is a problem that continues to challenge the healthcare sector, especially in clinically significant pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Herein is described the isolation and structure elucidation of a bioactive compound from Allium stipitatum with antimicrobial activity. Crude Allium stipitatum dichloromethane extract (ASDE) was subjected to systematic purification by chromatographic procedures to afford various bioactive fractions. A fraction that exhibited anti-MRSA activity (4 µg·mL−1) was further characterized to determine the structure. The structure of the compound was elucidated as 2-(methyldithio)pyridine-3-carbonitrile (2-Medpy-3-CN). The 2-Medpy-3-CN compound, which was screened for antimicrobial activity, exhibited minimum inhibitory concentrations (MICs) in the range of 0.5 to >64 µg·mL−1 for tested bacterial species and 0.25 to 2 µg·mL−1 for Candida spp. Further studies are important to confirm the drug target and mechanism of action. [ABSTRACT FROM AUTHOR]

Iron has been shown to regulate biofilm formation, oxidative stress response and several pathogenic mechanisms in Stenotrophomonas maltophilia. Thus, the present study is aimed at identifying various iron acquisition systems and iron sources utilized during iron starvation in S. maltophilia. The annotations of the complete genome of strains K279a, R551-3, D457 and JV3 through Rapid Annotations using Subsystems Technology (RAST) revealed two putative subsystems to be involved in iron acquisition: the iron siderophore sensor and receptor system and the heme, hemin uptake and utilization systems/hemin transport system. Screening for these acquisition systems in S. maltophilia showed the presence of all tested functional genes in clinical isolates, but only a few in environmental isolates. NanoString nCounter Elements technology, applied to determine the expression pattern of the genes under iron-depleted condition, showed significant expression for FeSR (6.15-fold), HmuT (12.21-fold), Hup (5.46-fold), ETFb (2.28-fold), TonB (2.03-fold) and Fur (3.30-fold). The isolates, when further screened for the production and chemical nature of siderophores using CAS agar diffusion (CASAD) and Arnows’s colorimetric assay, revealed S. maltophilia to produce catechol-type siderophore. Siderophore production was also tested through liquid CAS assay and was found to be greater in the clinical isolate (30.8%) compared to environmental isolates (4%). Both clinical and environmental isolates utilized hemoglobin, hemin, transferrin and lactoferrin as iron sources. All data put together indicates that S. maltophilia utilizes siderophore-mediated and heme-mediated systems for iron acquisition during iron starvation. These data need to be further confirmed through several knockout studies. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Leptospira detection of 14.3% was recorded among the 266 small mammals captured. • R. norvegicus , R. rattus , M. whiteheadi , S. muelleri , T. gliss , R. tiomanicus and S. murinus carried pathogenic leptospires. • ST110 L. kirschneri Grippotyphosa, ST242 L. weilii , ST50 L. interrogans Bataviae ST143 L. borgpetersenii Javanica were detected. • To include the isolated local strains into MAT panel to enhance the leptospirosis diagnostic efficacy in Malaysia. Abstract Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32 , secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans , ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus , 7/59 (11.9%) of Rattus rattus , 5/24 (20.8%) of Maxomys whiteheadi , 4/18 (22.2%) of Sundamys muelleri , 2/22 (9%), Tupaia gliss , 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures. [ABSTRACT FROM AUTHOR]

Introduction: Hajj is a unique religious mass gathering among Muslims hosted by Kingdom of Saudi Arabia (KSA) annually. It is a fifth pillar that is compulsory to be carried among muslim. Infections due to Neisseria meningitidis, Streptococcus Pneumoniae and Influenza virus are very high among Hajj pilgrims in KSA. Study shows knowledge and attitude towards vaccine preventable disease and vaccination which is very important for the prevention of these infectious diseases. This study aims to determine knowledge and attitude among the prospective Malaysian hajj pilgrims on vaccine preventable disease and vaccination. Method: A cross sectional study was conducted among prospective hajj pilgrims in June 2019. Self-administered questionnaires were given to the respondents through simple random sampling. The socio-demographic characteristics were described using descriptive analysis. Chi-square test was used to analyse the association between the socio-demographic and Malaysian hajj pilgrims' knowledge and attitude towards the vaccine preventable diseases and vaccination. Results: A total of 135 respondents were recruited in the study. There were statistically significant associations between the knowledge and the highest education level (p=0.01), and also between the knowledge and the occupation (p=0.02) on vaccine preventable disease and vaccination. Conclusion: There is a lack of knowledge among the Malaysian hajj pilgrims about these vaccine preventable diseases and vaccination, especially those who have lower education level and also unemployed. Tabung Haji are highly advised to focus on these group and prepare a special course that focused on these vaccine preventable diseases so that Malaysian Hajj pilgrims will be protected. [ABSTRACT FROM AUTHOR]

• C. difficile was common in piglets and piggeries in Thailand and Malaysia. • All C. difficile isolated were non-toxigenic with ribotype 038 most prevalent. • Ribotype 038 strains from piglets in Malaysia and Thailand were 18 SNVs apart. • Ribotype 038 from piglets and humans in Asia were on average 30 SNVs apart. Information on the epidemiology of C. difficile infection (CDI) in South-East Asian countries is limited, as is data on possible animal reservoirs of C. difficile in the region. We investigated the prevalence and molecular epidemiology of C. difficile in piglets and the piggery environment in Thailand and Malaysia. Piglet rectal swabs (n = 224) and piggery environmental specimens (n = 23) were collected between 2015 and 2016 from 11 farms located in Thailand and Malaysia. All specimens were tested for the presence of C. difficile with toxigenic culture. PCR assays were performed on isolates to determine the ribotype (RT), and the presence of toxin genes. Whole genome sequencing was used on a subset of isolates to determine the evolutionary relatedness of RT038 (the most prevalent RT identified) common to pigs and humans from Thailand and Indonesia. C. difficile was recovered from 35% (58/165) and 92% (54/59) of the piglets, and 89% (8/9) and 93% (13/14) of the environmental specimens from Thailand and Malaysia, respectively. All strains from Thailand, and 30 strains from Malaysia (23 piglet and 7 environmental isolates) were non-toxigenic. To our knowledge, this is the first and only report with a complete lack of toxigenic C. difficile among piglets, a feature which could have a protective effect on the host. The most common strain belonged to RT038 (ST48), accounting for 88% (51/58) of piglet and 78% (7/9) of environmental isolates from Thailand, and all 30 isolates tested from Malaysia. Piglet RT038 isolates from Thailand and Malaysia differed by only 18 core-genome single nucleotide variants (cgSNVs) and both were, on average, 30 cgSNVs different from the human strains from Thailand and Indonesia, indicating a common ancestor in the last two decades. [ABSTRACT FROM AUTHOR]

A state-wide prospective longitudinal investigation of the genomic surveillance of the omicron B.1.1.529 SARS-CoV-2 variant and its sublineages in Tamil Nadu, India, was conducted between December 2021 and March 2023. The study aimed to elucidate their mutational patterns and their genetic interrelationship in the Indian population. The study identified several unique mutations at different time-points, which likely could attribute to the changing disease characteristics, transmission, and pathogenicity attributes of omicron variants. The study found that the omicron variant is highly competent in its mutating potentials, and that it continues to evolve in the general population, likely escaping from natural as well as vaccine-induced immune responses. Our findings suggest that continuous surveillance of viral variants at the global scenario is warranted to undertake intervention measures against potentially precarious SARS-CoV-2 variants and their evolution., (© 2024 Wiley Periodicals LLC.)

In South East Asia, Streptococcus agalactiae ST283 causes sepsis in healthy adults. Raw freshwater fish consumption is the only known risk factor. These two case reports are the first from Malaysia. Although they cluster with Singapore ST283, the epidemiology is complicated by the flow of people and fish across borders.

Countries around the world are gearing for the transition of the coronavirus disease 2019 (COVID-19) from pandemic to endemic phase but the emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants could lead to a prolonged pandemic. SARS-CoV-2 has continued to evolve as it optimizes its adaptation to the human host and the successive waves of COVID-19 have been linked to the explosion of particular variant of concern. As the genetic diversity and epidemiological landscape of SARS-CoV-2 differ from country to country, this study aims to provide insights into the variants that are circulating in Malaysia. Whole genome sequencing was performed for 204 SARS-CoV-2 from COVID-19 cases and an additional 18,667 SARS-CoV-2 genome sequences were retrieved from the GISAID EpiCoV database for clade, lineage and genetic variation analyses. Complete genome sequences with high coverage were then used for phylogeny investigation and the resulting phylogenetic tree was constructed from 8,716 sequences. We found that the different waves of COVID-19 in Malaysia were dominated by different clades with the L and O clade for first and second wave, respectively, whereas the progressive replacement by G, GH, and GK of the GRA clade were observed in the subsequence waves. Continuous monitoring of the genetic diversity of SARS-CoV-2 is important to identify the emergence and dominance of new variant in different locality so that the appropriate countermeasures can be taken to effectively contain the spread of SARS-CoV-2., Competing Interests: The 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 © 2022 Yu, Wong, Liew, Joseph, Zakaria, Nurulfiza, Soe, Kairon, Amin-Nordin and Chee.)

The rapid spread of SARS-CoV-2 variants in the global population is indicative of the development of selective advantages in emerging virus strains. Here, we performed a case-control investigation of the clinical and demographic characteristics, clinical history, and virological markers to predict disease progression in hospitalized adults for COVID-19 between December 2021 and January 2022 in Chennai, India. COVID-19 diagnosis was made by a commercial TaqPath COVID-19 RT-PCR, and WGS was performed with the Ion Torrent Next Generation Sequencing System. High-quality (<5% of N) complete sequences of 73 Omicron B.1.1.529 variants were randomly selected for phylogenetic analysis. SARS-CoV-2 viral load, number of comorbidities, and severe disease presentation were independently associated with a shorter time-to-death. Strikingly, this was observed among individuals infected with Omicron BA.2 but not among those with the BA.1.1.529, BA.1.1, or the Delta B.1.617.2 variants. Phylogenetic analysis revealed severe cases predominantly clustering under the BA.2 lineage. Sequence analyses showed 30 mutation sites in BA.1.1.529 and 33 in BA.1.1. The mutations unique to BA.2 were T19I, L24S, P25del, P26del, A27S, V213G, T376A, D405N and R408S. Low SARS-CoV-2 viral load among vaccinated individuals infected with Delta B.1.617.2 and the Omicron BA.1.1.529 variant but not with Omicron BA.1.1 or BA.2 suggests that the newer strains are largely immune escape variants. The number of vaccine doses received was independently associated with increased odds of developing asymptomatic disease or recovery. We propose that the novel mutations reported herein could likely bear a significant impact on the clinical characteristics, disease progression, and epidemiological aspects of COVID-19. Surging rates of mutations and the emergence of eclectic variants of SARS-CoV-2 appear to impact disease dynamics., Competing Interests: The 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 © 2022 Selvavinayagam, Yong, Joseph, Hemashree, Tan, Zhang, Rajeshkumar, Kumaresan, Kalpana, Kalaivani, Monika, Suvaithenamudhan, Kannan, Murugesan, Narayanasamy, Palani, Larsson, Shankar and Raju.)

Leptospirosis is a zoonotic disease mostly occurring in tropical climate countries. The etiology of the disease is due to microbes from the genus Leptospira . Higher number of cases reported worldwide indicated the disease is not easily eradicated. Leptospirosis shares the most common febrile symptoms such as dengue, Zika and yellow fever thus making it difficult to differentiate the disease at an early stage. The widely used current detection via PCR, uses the bacterial outer membrane protein (OMP) as their target region. However, the heterogeneity and variation of the genome cause false negative results. Lipoprotein LipL41 is the third most abundant outer membrane lipoprotein among pathogenic species and it is surface exposed and expressed during infection thus making it a suitable candidate in identifying pathogenic Leptospira . LipL21 on the other hand is a potential candidate in identifying the intermediate species. The study aimed in designing suitable PCR primers in identifying pathogenic and intermediate species of Leptospira through bioinformatics analysis on the bacterial OMPs. LipL41 and LipL21 were chosen as the suitable target sequence to be used as PCR primers in detecting the pathogenic and intermediate species, respectively. The designed primers indicated positive feedback upon tested with their respective bacterial DNA extract. These lipoproteins may serve as potential PCR primers to be used with clinical samples in diagnosing leptospirosis.•The etiology of the illness is due to bacteria from the genus Leptospira .•PCR utilizes the bacterial external membrane protein (OMP) thus the heterogeneity and variety of the genome cause bogus adverse outcomes.•The suitable candidates are LipL41, the third most abundant outer membrane lipoprotein, whereas LipL21 is a potential candidate in identifying the intermediate species., Competing Interests: None., (© 2022 The Author(s).)

Background and Objectives : Matrix metalloproteinases (MMP) have been implicated as major determinants of tumour growth and metastasis, which are considered two of the main hallmarks of cancer. The interaction of MMP8 and other signalling molecules within and adjacent tumoral tissues, including immune cells, are rather elusive, particularly of adenocarcinoma cell type. In this study, we aimed to investigate the role of MMP8 in non-small cell lung cancer proliferation and invasiveness potential. Materials and Methods : We individually lipofected with two different single guide RNA (sgRNAs) that specifically targeted on MMP8 , with CRISPR-Cas 9 protein into the cells. Results : Our results clearly indicated that the lipofection of these complexes could lead to reduced ability of A549 cells to survive and proliferate to form colonies. In addition, when compared to non-transfected cells, the experimental cell groups receiving sgRNAs demonstrated relatively decreased migration rate, hence, wider wound gaps in scratch assay. The quantitative real time-polymerase chain reaction (qRT-PCR) demonstrated significant reduction in the MAP-K , survivin and PI3-K gene expression. MMP8 might have protective roles over tumour growth and spread in our body. Conclusions : The delivery of sgRNAs targeting on the MMP8 gene could induce tumour cell death and arrest cell migratory activity.

Extensive clinical efforts have been made to control the severity of dengue diseases; however, the dengue morbidity and mortality have not declined. Dengue virus (DENV) can infect and cause systemic damage in many organs, resulting in organ failure. Here, we present a novel report showing a tailored stem-cell-based therapy that can aid in viral clearance and rescue liver cells from further damage during dengue infection. We administered a combination of hematopoietic stem cells and endothelial progenitor cells in a DENV-infected BALB/c mouse model and found that delivery of this cell cocktail had improved their liver functions, confirmed by hematology, histopathology, and next-generation sequencing. These stem and progenitor cells can differentiate into target cells and repair the damaged tissues. In addition, the regime can regulate endothelial proliferation and permeability, modulate inflammatory reactions, enhance extracellular matrix production and angiogenesis, and secrete an array of growth factors to create an enhanced milieu for cell reparation. No previous study has been published on the treatment of dengue infection using stem cells combination. In conclusion, dengue-induced liver damage was rescued by administration of stem cell therapy, with less apoptosis and improved repair and regeneration in the dengue mouse model., Competing Interests: The 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. The reviewer RR declared a shared affiliation, with no collaboration, with one of the authors, AH, to the handling editor at the time of the review., (Copyright © 2021 Sakinah, Priya, Mok, Munisvaradass, Teh, Sun, Alzahrani, Abu Bakar, Chee, Awang Hamat, He, Xiong, Joseph, Tong, Wu, Maniam, Samrot, Higuchi and Kumar.)

Aims: To study physiological and proteomic analysis of Stenotrophomonas maltophilia grown under iron-limited condition. Methods: One clinical and environmental S. maltophilia isolates grown under iron-depleted conditions were studied for siderophore production, ability to kill nematodes and alteration in protein expression using isobaric tags for relative and absolute quantification (ITRAQ). Results & conclusions: Siderophore production was observed in both clinical and environmental strains under iron-depleted conditions. Caenorhabditis elegans assay showed higher killing rate under iron-depleted (96%) compared with normal condition (76%). The proteins identified revealed, 96 proteins upregulated and 26 proteins downregulated for the two isolates under iron depletion. The upregulated proteins included several iron acquisition proteins, metabolic proteins and putative virulence proteins.