Respiratory carriage of hypervirulent Klebsiella pneumoniae by indigenous populations of Malaysia.

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 ß-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.

Prevalence of true resistant hypertension in those referred for uncontrolled hypertension in Malaysia: A comparison using different definitions.

Resistant hypertension is a well-recognised clinical challenge. However, the definition and epidemiology of true resistant hypertension (RH) are less understood, especially in Asia. This cross-sectional study examined the prevalence of RH referred from primary care clinics based on various guidelines. RH was defined as blood pressure (BP) being above the threshold using ambulatory blood pressure monitoring despite adequate lifestyle measures and optimal treatment with ≥3 medications at maximally tolerated doses. Between one in four (n = 94, 24.0% using Malaysian guidelines) and up to two-thirds (n = 249, 63.7% using 2018 American guidelines) of adults referred for uncontrolled hypertension met the criteria of true RH. Of those with RH, a further one-quarter (n = 26, 26.6%) were deemed to have refractory hypertension (elevated BP despite treatment with at least 5 antihypertensive medications). Adults with RH were generally younger, more likely to be male, had a higher BMI and were more likely to have gout, CKD, and angina compared to those with controlled hypertension. The prevalence of RH amongst Asian adults with poor hypertension control is high. A concerted effort is needed to reduce the high burden of RH, especially among this population.

Genomic comparison and phenotypic profiling of small colony variants of Burkholderia pseudomallei.

Burkholderia pseudomallei (B. pseudomallei) is an intracellular pathogen that causes melioidosis, a life-threatening infection in humans. The bacterium is able to form small colony variants (SCVs) as part of the adaptive features in response to environmental stress. In this study, we characterize the genomic characteristics, antimicrobial resistance (AMR), and metabolic phenotypes of B. pseudomallei SCV and wild type (WT) strains. Whole-genome sequence analysis was performed to characterize the genomic features of two SCVs (CS and OS) and their respective parental WT strains (CB and OB). Phylogenetic relationship between the four draft genomes in this study and 19 publicly available genomes from various countries was determined. The four draft genomes showed a close phylogenetic relationship with other genomes from Southeast Asia. Broth microdilution and phenotype microarray were conducted to determine the AMR profiles and metabolic features (carbon utilization, osmolytes sensitivity, and pH conditions) of all strains. The SCV strains exhibited identical AMR phenotype with their parental WT strains. A limited number of AMR-conferring genes were identified in the B. pseudomallei genomes. The SCVs and their respective parental WT strains generally shared similar carbon-utilization profiles, except for D,L-carnitine (CS), g-hydroxybutyric acid (OS), and succinamic acid (OS) which were utilized by the SCVs only. No difference was observed in the osmolytes sensitivity of all strains. In comparison, WT strains were more resistant to alkaline condition, while SCVs showed variable growth responses at higher acidity. Overall, the genomes of the colony morphology variants of B. pseudomallei were largely identical, and the phenotypic variations observed among the different morphotypes were strain-specific.

Carriage of upper respiratory tract pathogens in rural communities of Sarawak, Malaysian Borneo.

INTRODUCTION: Pneumonia is a leading cause of death in Malaysia. Whilst many studies have reported the aetiology of pneumonia in Western countries, the epidemiology of pneumonia in Malaysia remains poorly understood. As carriage is a prerequisite for disease, we sought to improve our understanding of the carriage and antimicrobial resistance (AMR) of respiratory tract pathogens in Malaysia. The rural communities of Sarawak are an understudied part of the Malaysian population and were the focus of this study, allowing us to gain a better understanding of bacterial epidemiology in this population. METHODS: A population-based survey of bacterial carriage was undertaken in participants of all ages from rural communities in Sarawak, Malaysia. Nasopharyngeal, nasal, mouth and oropharyngeal swabs were taken. Bacteria were isolated from each swab and identified by culture-based methods and antimicrobial susceptibility testing conducted by disk diffusion or E test. RESULTS: 140 participants were recruited from five rural communities. Klebsiella pneumoniae was most commonly isolated from participants (30.0%), followed by Staphylococcus aureus (20.7%), Streptococcus pneumoniae (10.7%), Haemophilus influenzae (9.3%), Moraxella catarrhalis (6.4%), Pseudomonas aeruginosa (6.4%) and Neisseria meningitidis (5.0%). Of the 21 S. pneumoniae isolated, 33.3 and 14.3% were serotypes included in the 13 valent PCV (PCV13) and 10 valent PCV (PCV10) respectively. 33.8% of all species were resistant to at least one antibiotic, however all bacterial species except S. pneumoniae were susceptible to at least one type of antibiotic. CONCLUSION: To our knowledge, this is the first bacterial carriage study undertaken in East Malaysia. We provide valuable and timely data regarding the epidemiology and AMR of respiratory pathogens commonly associated with pneumonia. Further surveillance in Malaysia is necessary to monitor changes in the carriage prevalence of upper respiratory tract pathogens and the emergence of AMR, particularly as PCV is added to the National Immunisation Programme (NIP).

Neonatal intensive care unit (NICU) exposures exert a sustained influence on the progression of gut microbiota and metabolome in the first year of life.

Emerging evidence has shown a link between the perturbations and development of the gut microbiota in infants with their immediate and long-term health. To better understand the assembly of the gut microbiota in preterm infants, faecal samples were longitudinally collected from the preterm (n = 19) and term (n = 20) infants from birth until month 12. 16S rRNA gene sequencing (n = 141) and metabolomics profiling (n = 141) using nuclear magnetic resonance spectroscopy identified significant differences between groups in various time points. A panel of amino acid metabolites and central metabolism intermediates significantly correlated with the relative abundances of 8 species of bacteria were identified in the preterm group. In contrast, faecal metabolites of term infants had significantly higher levels of metabolites which are commonly found in milk such as fucose and ß-hydroxybutyrate. We demonstrated that the early-life factors such as gestational age, birth weight and NICU exposures, exerted a sustained effect to the dynamics of gut microbial composition and metabolism of the neonates up to one year of age. Thus, our findings suggest that intervention at this early time could provide 'metabolic rescue' to preterm infants from aberrant initial gut microbial colonisation and succession.

Gut Microbial Ecosystem in Parkinson Disease: New Clinicobiological Insights from Multi-Omics.

OBJECTIVE: Gut microbiome alterations in Parkinson disease (PD) have been reported repeatedly, but their functional relevance remains unclear. Fecal metabolomics, which provide a functional readout of microbial activity, have scarcely been investigated. We investigated fecal microbiome and metabolome alterations in PD, and their clinical relevance. METHODS: Two hundred subjects (104 patients, 96 controls) underwent extensive clinical phenotyping. Stool samples were analyzed using 16S rRNA gene sequencing. Fecal metabolomics were performed using two platforms, nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry. RESULTS: Fecal microbiome and metabolome composition in PD was significantly different from controls, with the largest effect size seen in NMR-based metabolome. Microbiome and NMR-based metabolome compositional differences remained significant after comprehensive confounder analyses. Differentially abundant fecal metabolite features and predicted functional changes in PD versus controls included bioactive molecules with putative neuroprotective effects (eg, short chain fatty acids [SCFAs], ubiquinones, and salicylate) and other compounds increasingly implicated in neurodegeneration (eg, ceramides, sphingosine, and trimethylamine N-oxide). In the PD group, cognitive impairment, low body mass index (BMI), frailty, constipation, and low physical activity were associated with fecal metabolome compositional differences. Notably, low SCFAs in PD were significantly associated with poorer cognition and low BMI. Lower butyrate levels correlated with worse postural instability-gait disorder scores. INTERPRETATION: Gut microbial function is altered in PD, characterized by differentially abundant metabolic features that provide important biological insights into gut-brain pathophysiology. Their clinical relevance further supports a role for microbial metabolites as potential targets for the development of new biomarkers and therapies in PD. ANN NEUROL 2021;89:546-559.

Comparative assessment of faecal microbial composition and metabonome of swine, farmers and human control.

The gastrointestinal tract of humans and swine consist of a wide range of bacteria which interact with hosts metabolism. Due to the differences in co-evolution and co-adaptation, a large fraction of the gut microbiome is host-specific. In this study, we evaluated the effect of close human-animal interaction to the faecal metagenome and metabonome of swine, farmer and human control. Three distinct clusters were observed based on T-RFLP-derived faecal microbial composition. However, 16S-inferred faecal microbiota and metabolic profiles showed that only human control was significantly different from the swine (P < 0.05). The metabonome of farmers and human controls were highly similar. Notably, higher trimethylamine N-oxide (TMAO) and butyrate were detected in human control and swine, respectively. The relative abundance of TMAO was positively correlated with Prevotella copri. Overall, we compared and established the relationship between the metabolites and microbiota composition of swine, farmers and human control. Based on the data obtained, we deduced that long term occupational exposure to swine and farm environment had affected the gut bacterial composition of farmers. Nonetheless, the effect was less prominent in the metabolite profiles, suggesting the gut bacteria expressed high functional plasticity and are therefore resilience to the level of community shift detected.

Whole genome analysis of multidrug-resistant Citrobacter freundii B9-C2 isolated from preterm neonate's stool in the first week.

BACKGROUND: Resistance to colistin, the last line therapy for infections caused by multidrug-resistant Gram-negative bacteria, represents a major public health threat. Citrobacter freundii B9-C2 which was isolated from the stool of preterm neonate on the first week of life, displayed resistance to almost all major antibiotics, including colistin. Through whole genome sequencing (WGS), we characterised the genome features that underline the antibiotic-resistance phenotype of this isolate. METHODS: Genome of C. freundii B9-C2 was sequenced on an Illumina MiSeq platform. The assembled genome was annotated and deposited into GenBank under the accession number CP027849. RESULTS: Multiple antimicrobial resistance genes including blaCMY-66 were identified. Further, the presence of 15 antibiotic efflux pump-encoding resistance genes, including crp, baeR, hns, patA, emrB, msbA, acrA, acrB, emrR, mdtC, mdtB, mdtG, kdpE, mdfA and msrB, were detected and likely to account for the observed cephalosporins, carbapenems, aminoglycosides and monobactams resistance in C. freundii B9-C2. The isolate also presented unique virulence genes related to biofilm formation, motility and iron uptake. The genome was compared to publicly available genomes and it was closely related to strains with environmental origins. CONCLUSION: To the best of our knowledge, this is the first report of intestinal carriage of colistin-resistant C. freundii from the stool of a neonate in Malaysia. Using genomic analysis, we have contributed to the understanding of the potential mechanism of resistance and the phylogenetic relationship of the isolates with draft genomes available in the public domain.

Sylvatic dengue virus type 4 in Aedes aegypti and Aedes albopictus mosquitoes in an urban setting in Peninsular Malaysia.

Dengue fever is endemic in Malaysia, contributing to significant economic and health burden in the country. Aedes aegypti and Ae. albopictus are the main vectors of the dengue virus (DENV), which circulates in sylvatic and human transmission cycles and has been present in Malaysia for decades. The study investigated the presence and distribution of DENV in urban localities in the Klang Valley, Peninsular Malaysia. A total of 364 Ae. aegypti and 1,025 Ae. albopictus larvae, and 10 Ae. aegypti and 42 Ae. albopictus adult mosquitoes were screened for the presence of DENV. In total, 31 (2.2%) samples were positive, of which 2 Ae. albopictus larvae were co-infected with two serotypes, one with DENV-2 and DENV-3 and the other with DENV-3 and DENV-4. Phylogenetic analysis determined that the isolates belonged to DENV-1 genotype I (1 Ae. aegypti adult), DENV-2 (1 Ae. albopictus larva), DENV-3 genotype V (3 Ae. aegypti larvae and 10 Ae. albopictus larvae) and DENV-4 genotype IV (6 Ae. aegypti larvae and 12 Ae. albopictus larvae), a sylvatic strain of DENV-4 which was most closely related with sylvatic strains isolated from arboreal mosquitoes and sentinel monkeys in Peninsular Malaysia in the 1970s. All four DENV serotypes were co-circulating throughout the study period. The detection of a sylvatic strain of DENV-4 in Ae. aegypti and Ae. albopictus mosquitoes in urban areas in Peninsular Malaysia highlights the susceptibility of these vectors to infection with sylvatic DENV. The infectivity and vector competence of these urban mosquitoes to this strain of the virus needs further investigation, as well as the possibility of the emergence of sylvatic virus into the human transmission cycle.

Raised levels of Il-6, Il-17a, and Il-22 in fatal leptospirosis.

Clinical manifestations of leptospirosis range from mild, common cold-like illness, to a life-threatening condition. The host immune response has been hypothesized to play a major role in leptospirosis outcome. Increased levels of inflammatory mediators, such as cytokines, may promote tissue damage that lead to increased disease severity. The question is whether cytokines levels may predict the outcome of leptospirosis and guide patient management. This study aimed to assess the association between Th1-, Th2-, and Th17-related cytokines with the clinical outcome of patients with leptospirosis. Different cytokine levels were measured in fifty-two plasma samples of hospitalized patients diagnosed with leptospirosis in Malaysia (January 2016-December 2017). Patients were divided into two separate categories: survived (n = 40) and fatal outcome (n = 12). Nineteen plasma samples from healthy individuals were obtained as controls. Cytokine quantification was performed using Simple Plex™ assays from ProteinSimple (San Jose, CA, USA). Measurements were done in triplicate and statistical analysis was performed using GraphPad software and SPSS v20. IL-6 (p = 0.033), IL-17A (p = 0.022), and IL-22 (p = 0.046) were significantly elevated in fatal cases. IL-17A concentration (OR 1.115; 95% CI 1.010-1.231) appeared to be an independent predictor of fatality of leptospirosis. Significantly higher levels of TNF-α (p ≤ 0.0001), IL-6 (p ≤ 0.0001), IL-10 (p ≤ 0.0001), IL-12 (p ≤ 0.0001), IL17A (p ≤ 0.0001), and IL-18 (p ≤ 0.0001) were observed among leptospirosis patients in comparison with healthy controls. Our study shows that certain cytokine levels may serve as possible prognostic biomarkers in leptospirosis patients.

Role of coaggregation in the pathogenicity and prolonged colonisation of Vibrio cholerae.

Cholera is an acute diarrheal illness caused by the Gram-negative bacterium Vibrio cholerae. The pathogen is known for its ability to form biofilm that confers protection against harsh environmental condition and as part of the colonisation process during infection. Coaggregation is a process that facilitates the formation of biofilm. In a preliminary in vitro study, high coaggregation index and biofilm production were found between V. cholerae with human commensals namely Escherichia coli and Enterobacter cloacae. Building upon these results, the effects of coaggregation were further evaluated using adult BALB/c mouse model. The animal study showed no significant differences in mortality and fluid accumulation ratio between treatment groups infected with V. cholerae alone and those infected with coaggregation partnership (V. cholerae with E. coli or V. cholerae with E. cloacae). However, mild inflammation was detected in both partnering pairs. Higher density of V. cholerae was recovered from faecal samples of mice co-infected with E. coli and V. cholerae in comparison with other groups at 24 h post-infection. This partnership also elicited slightly higher levels of interleukin-5 (IL-5) and interleukin-10 (IL-10). Nonetheless, the involvement of autoinducer-2 (AI-2) as the signalling molecules in quorum sensing system is not evident in this study. Since E. coli is one of the common commensals, our result may suggest the involvement of commensals in cholera development.

Elucidating the survival and response of carbapenem resistant Klebsiella pneumoniae after exposure to imipenem at sub-lethal concentrations.

The increasing prevalence of antibiotic resistant pathogens poses a serious threat to global health. However, less emphasis has been placed to co-relate the gene expression and metabolism of antibiotic resistant pathogens. This study aims to elucidate gene expression and variations in metabolism of multidrug resistant Klebsiella pneumoniae after exposure to antibiotics. Phenotypic responses of three genotypically distinct carbapenem resistant Klebsiella pneumoniae (CRKP) strains untreated and treated with sub-lethal concentrations of imipenem were investigated via phenotype microarrays (PM). The gene expression and metabolism of the strain harboring blaNDM-1 before and after exposure to sub-lethal concentration of imipenem were further investigated by RNA-sequencing (RNA-Seq) and 1H NMR spectroscopy respectively. Most genes related to cell division, central carbon metabolism and nucleotide metabolism were downregulated after imipenem treatment. Similarly, 1H NMR spectra obtained from treated CRKP showed decrease in levels of bacterial end products (acetate, pyruvate, succinate, formate) and metabolites involved in nucleotide metabolism (uracil, xanthine, hypoxanthine) but elevated levels of glycerophosphocholine. The presence of anserine was also observed for the treated CRKP while FAPγ-adenine and methyladenine were only present in untreated bacterial cells. As a conclusion, the studied CRKP strain exhibited decrease in central carbon metabolism, cell division and nucleotide metabolism after exposure to sub-lethal concentrations of imipenem. The understanding of the complex biological system of this multidrug resistant bacterium may help in the development of novel strategies and potential targets for the management of the infections.

Isolation and Quantification of Mimivirus-Like and Marseillevirus-Like Viruses from Soil Samples in An Aboriginal (Orang asli) Village in Peninsular Malaysia.

BACKGROUND: The giant amoebal viruses of Mimivirus and Marseillevirus are large DNA viruses and have been documented in water, soil, and sewage samples. The trend of discovering these giant amoebal viruses has been increasing throughout Asia with Japan, India, and Saudi Arabia being the latest countries to document the presence of these viruses. To date, there have been no reports of large amoebal viruses being isolated in South East Asia. OBJECTIVE: In this study, we aim to discover these viruses from soil samples in an aboriginal village (Serendah village) in Peninsular -Malaysia. METHOD AND RESULTS: We successfully detected and isolated both Mimivirus-like and Marseillevirus-like viruses using Acanthamoeba castellanii. Phylogeny analysis identified them as Mimivirus and Marseillevirus, respectively. CONCLUSION: The ubiquitous nature of both Mimivirus and Marseillevirus is further confirmed in our study as they are detected in higher quantity in soil that is near to water vicinities in an aboriginal village in Peninsular Malaysia. However, this study is limited by our inability to investigate the impact of Mimivirus and Marseillevirus on the aboriginal villagers. More studies on the potential impact of these viruses on human health, especially on the aborigines, are warranted.

Pneumococcal conjugate vaccine implementation in middle-income countries.

BACKGROUND: Since 2000, the widespread adoption of pneumococcal conjugate vaccines (PCVs) has had a major impact in the prevention of pneumonia. Limited access to international financial support means some middle-income countries (MICs) are trailing in the widespread use of PCVs. We review the status of PCV implementation, and discuss any needs and gaps related to low levels of PCV implementation in MICs, with analysis of possible solutions to strengthen the PCV implementation process in MICs. MAIN BODY: We searched PubMed, PubMed Central, Ovid MEDLINE, and SCOPUS databases using search terms related to pneumococcal immunization, governmental health policy or programmes, and MICs. Two authors independently reviewed the full text of the references, which were assessed for eligibility using pre-defined inclusion and exclusion criteria. The search terms identified 1,165 articles and the full texts of 21 were assessed for suitability, with eight articles included in the systematic review. MICs are implementing PCVs at a slower rate than donor-funded low-income countries and wealthier developed countries. A significant difference in the uptake of PCV in lower middle-income countries (LMICs) (71%) and upper middle-income countries (UMICs) (48%) is largely due to an unsuccessful process of "graduation" of MICs from GAVI assistance, an issue that arises as countries cross the income eligibility threshold and are no longer eligible to receive the same levels of financial assistance. A lack of country-specific data on disease burden, a lack of local expertise in economic evaluation, and the cost of PCV were identified as the leading causes of the slow uptake of PCVs in MICs. Potential solutions mentioned in the reviewed papers include the use of vaccine cost-effectiveness analysis and the provision of economic evidence to strengthen decision-making, the evaluation of the burden of disease, and post-introduction surveillance to monitor vaccine impact. CONCLUSION: The global community needs to recognise the impediments to vaccine introduction into MICs. Improving PCV access could help decrease the incidence of pneumonia and reduce the selection pressure for pneumococcal antimicrobial resistance.

Intestinal carriage of multidrug-resistant gram-negative bacteria in preterm-infants during hospitalization in neonatal intensive care unit (NICU).

The prevalence and antibiotic susceptibility of intestinal carriage of Gram-negative bacteria among preterm infants admitted to the neonatal intensive care unit (NICU) in a tertiary teaching hospital in Malaysia were determined. A total of 34 stool specimens were obtained from preterm infants upon admission and once weekly up to two weeks during hospitalization. The presumptive colonies of Escherichia coli and Klebsiella pneumoniae were selected for identification, antibiotic susceptibility testing, and subtyping by using pulsed-field gel electrophoresis (PFGE). Out of 76 Gram-negative isolates, highest resistance was detected for amoxicillin/clavulanate (30.8%, n = 16), ceftriaxone (42.3%, n = 22), ceftazidime (28.8%, n = 15), cefoxitin (28.8%, n = 15), aztreonam (36.5%, n = 19), and polymyxin B (23.1%, n = 12). Three colistin resistant K. pneumoniae have also been detected based on E-test analysis. Thirty-nine isolates of K. pneumoniae and 20 isolates of E. coli were resistant to more than three antimicrobial classes and were categorized as multidrug resistant (MDR). PFGE analysis revealed a higher diversity in pulsotypes for K. pneumoniae (18 pulsotypes) in comparison to E. coli (four pulsotypes). In addition, a total of fifteen pulsotypes was observed from 39 MDR K. pneumoniae. The risk factors for antibiotic resistance were assessed using random forest analysis. Gender was found to be the most important predictor for colistin resistant while length, OFC, and delivery mode were showing greater predictive power in the polymyxin B resistance. This study revealed worrying prevalence rates of intestinal carriage of multidrug-resistant K. pneumoniae and E. coli of hospitalized preterm infants in Malaysia, particularly high resistance to polymyxins.

Prevalence and risk factors of intestinal parasitism among two indigenous sub-ethnic groups in Peninsular Malaysia.

BACKGROUND: Intestinal parasitic infections (IPIs) among indigenous people have been widely documented in Malaysia, however, the prevalence of these infections remains high. In the past, most studies have focused on specific species of parasites but polyparasitism has received limited attention. In addition, epidemiology studies on indigenous people tend to consider them as a homogenous group, whereas in reality different sub-ethnic groups have different cultural and living practices. Variations in living habits such as personal hygiene practices may predispose different groups to different parasitic infections. To better understand prevalence and risk factors of intestinal parasitism among different sub-ethnic groups, the present study was conducted among two sub-ethnic groups of indigenous people (Temuan and Mah Meri) residing in Selangor state, Malaysia. METHODS: A cross-sectional study that focused on two distinct sub-ethnic groups was carried out from February to September 2014. Faecal samples were collected from 186 participants and examined using the formalin-ether sedimentation technique. A molecular approach was adopted to conduct a genetic characterisation of the parasites. Additionally, questionnaires were administered to obtain information on the demographics, socio-economic backgrounds and behavioural risks relating to the participants, as well as information about their environments. Statistical analyses (i.e. binary and multivariate logistic regression analyses) were performed to measure risk factors. RESULTS: For Temuan communities, trichuriasis (64.2 %) was the most common infection found, preceding hookworm infection (34 %), ascariasis (7.5 %), giardiasis (14.2 %) and amoebiasis (7.5 %). As for the Mah Meri communities, trichuriasis (77.5 %) prevailed over ascariasis (21.3 %), hookworm (15 %), giardiasis (7.5 %) and amoebiasis (3.8 %). Significant differences in proportions of trichuriasis, ascariasis and hookworm infections were observed between the Temuan and Mah Meri sub-ethnic groups. Polyparasitism was more common among the Temuan sub-ethnic group (41.5 %) compared to the Mah Meri sub-ethnic group (32.5 %), with the majority of participants harbouring two parasites concurrently (Temuan: 33 %, Mah Meri: 20 %). Trichuris trichiura and Ascaris lumbricoides co-infections were most prevalent (10 %) among the Mah Meri communities, while a co-infection of T. trichiura with hookworm (19.8 %) was most common among the Temuan communities. Multivariate analyses showed that being unemployed, having a large family and drinking unboiled water were found to be significantly associated with intestinal parasitism. CONCLUSION: The present study highlights substantial polyparasitism and risk factors for infections in the Temuan and Mah Meri sub-ethnic groups. The high prevalence of IPIs among these two sub-ethnic groups indicates that parasitic infections are important health issues in these communities. Hence, it is imperative to implement sound intervention strategies such as periodic preventive chemotherapy coupled with health education in order to reduce and eradicate these infections.

Effect of ethnicity and socioeconomic variation to the gut microbiota composition among pre-adolescent in Malaysia.

Gut microbiota plays an important role in mammalian host metabolism and physiological functions. The functions are particularly important in young children where rapid mental and physical developments are taking place. Nevertheless, little is known about the gut microbiome and the factors that contribute to microbial variation in the gut of South East Asian children. Here, we compared the gut bacterial richness and composition of pre-adolescence in Northern Malaysia. Our subjects covered three distinct ethnic groups with relatively narrow range of socioeconomic discrepancy. These included the Malays (n = 24), Chinese (n = 17) and the Orang Asli (indigenous) (n = 20). Our results suggested a strong ethnicity and socioeconomic-linked bacterial diversity. Highest bacterial diversity was detected from the economically deprived indigenous children while the lowest diversity was recorded from the relatively wealthy Chinese children. In addition, predicted functional metagenome profiling suggested an over-representation of pathways pertinent to bacterial colonisation and chemotaxis in the former while the latter exhibited enriched gene pathways related to sugar metabolism.