Methods: We retrospectively analyzed 7329 colonoscopy procedures performed by 12 endoscopists between January 2012 and February 2014. The PDR, actual ADR, and estimated ADR of the entire, proximal, and distal colon, and within each colonic segment, in two patient age groups: <50 and ≥50 years, were calculated for each endoscopist.

Results: The overall polyp and adenoma prevalence rates were 19.1 and 9.3%, respectively. The average age of adenoma-positive patients was significantly higher than that of adenoma-negative patients (54 ± 12.6 years vs 42.9 ± 13.2 years, respectively). A total of 1739 polyps were removed, among which 826 were adenomas. More adenomatous polyps were found in the proximal colon (60.4%, 341/565) than in the distal colon (40.9%, 472/1154). Overall, both actual and estimated ADR correlated strongly at the entire colon level and within most colonic segments, except for the cecum and rectum. In both age groups, these parameters correlated strongly within the traverse colon and descending colon.

MATERIALS AND METHODS: Biofilm yield of 32 Helicobacter pylori strains (standard strain and 31 clinical strains) were determined by crystal-violet assay and grouped into poor, moderate and good biofilm forming groups. Whole genome sequencing of these 32 clinical strains was performed on the Illumina MiSeq platform. Annotation and comparison of the differences between the genomic sequences were carried out using RAST (Rapid Annotation using Subsystem Technology) and SEED viewer. Genes identified were confirmed using PCR.

RESULTS: Genes identified to be associated with biofilm formation in H. pylori includes alpha (1,3)-fucosyltransferase, flagellar protein, 3 hypothetical proteins, outer membrane protein and a cag pathogenicity island protein. These genes play a role in bacterial motility, lipopolysaccharide (LPS) synthesis, Lewis antigen synthesis, adhesion and/or the type-IV secretion system (T4SS). Deletion of cagA and cagPAI confirmed that CagA and T4SS were involved in H. pylori biofilm formation.

Methods: Here, we investigated the impact of the CYP2C19 genotype polymorphism and the success of triple therapy (fluoroquinolones/metronidazole/clarithromycin) on antibiotic-resistant strains in eradicating H. pylori in human subjects with non-ulcer dyspepsia (NUD), in human subjects with peptic ulcer disease (PUD) and in asymptomatic human subjects (positive and negative for H. pylori infection).

Results: Based on the CYP2C19 genotypes, determined by Droplet Digital PCR (ddPCR) analysis, we found 11.2%, 62.5% and 26.3% corresponding to rapid metabolizers, intermediate metabolizers and poor metabolizers, respectively. However, we did not find any significant effect for homozygous ABCB1 or CYP2C19*2 and CYP2C19*3 alleles. We detected several participants heterozygous for both ABCB1 and CYP2C19*2, CYP2C19*3 and CYP2C19*17 loci. The participants heterozygous for both ABCB1 and CYP2C19*2 and *3 loci should be defined as intermediate and poor metabolizers according to the haplotype analysis in the NUD, PUD and asymptomatic subjects.

Methods: We performed whole-genome sequencing on 121 H. pylori clinical strains, among which 73 were metronidazole-resistant. Sequence-alignment analysis of core protein clusters derived from clinical strains containing full-length RdxA was performed. Variable sites in each alignment were statistically compared between the resistant and susceptible groups to determine candidate genes along with their respective amino-acid changes that may account for the development of metronidazole resistance in H. pylori.

Results: Resistance due to RdxA truncation was identified in 34% of metronidazole-resistant strains. Analysis of core protein clusters derived from the remaining 48 metronidazole-resistant strains and 48 metronidazole-susceptible identified four variable sites significantly associated with metronidazole resistance. These sites included R16H/C in RdxA, D85N in the inner-membrane protein RclC (HP0565), V265I in a biotin carboxylase protein (HP0370) and A51V/T in a putative threonylcarbamoyl-AMP synthase (HP0918).

METHODS: Healthy young adult volunteers between the ages of 18-30 years were consecutively recruited from June 2012 to May 2014 at the University of Malaya Medical Centre (UMMC), Kuala Lumpur. Serum samples from all the participants were tested for anti-gliadin antibody immunoglobulin A/immunoglobulin G (IgA/IgG) and anti-tissue transglutaminase antibody (tTG) IgA/IgG. Samples positive for both anti-gliadin and anti-tTG were further validated for anti-human endomysial IgA antibodies (EmA). Serological diagnosis of CD was made when anti-gliadin, anti-tTG and anti-EmA were positive.

RESULTS: 562 qualified participants with mean age 24 ± 2.4 years old were recruited into our study. CD was found in 7 participants where most of them were asymptomatic and unaware of their CD status. The median of anti-gliadin and anti-tTG IgA/IgG value was 38.2 U/ml (interquartile range, 28.3-60.4 U/ml) and 49.2 U/ml (interquartile range, 41.1-65.9 U/ml), respectively. Seroprevalence of CD antibodies was 1.9% (6 out of 324) in female while only 0.4% (1 out of 238) in male. Seroprevalence among Malay was 0.8% (2 of 236), Chinese was 1.7% (3 of 177) and Indian was 1.3% (2 of 149). Overall, seroprevalence of CD antibodies in healthy asymptomatic adults in the Malaysian population was 1.25% (95% CI, 0.78%-1.72%). No significant relationship was discovered between CD and H. pylori infection.