Infection with Helicobacter pylori cagA-positive strains is associated with gastroduodenal diseases. The CagA protein is injected into gastric epithelial cells and supposedly induces morphological changes termed the ‘hummingbird phenotype’, which is associated with scattering and increased cell motility. The molecular mechanisms leading to the CagA-dependent morphological changes are only partially known. The present study was carried out to investigate the effect of CagA variants on the magnitude of gastric epithelial cell morphological changes. Recombinant 3’ terminal domains of cagA were cloned and expressed in a gastric epithelial cell line and the hummingbird phenotype was quantifi ed by microscopy. The 3’ region of the cagA gene of Malaysian H. pylori isolates showed six sub-genotypes that differed in the structural organization of the EPIYA repeat sequences. The percentage of hummingbird cells induced by CagA increased with duration of transfection. The hummingbird phenotype was observed to be more pronounced when CagA with 4 EPIYA motifs rather than 3 or 2 EPIYA motifs was produced. The activity of different CagA variants in the induction of the hummingbird phenotype in gastric epithelial cells depends at least in part on EPIYA motif variability. The difference in CagA genotypes might infl uence the potential of individual CagAs to cause morphological changes in host cells. Depending on the relative exposure of cells to CagA genotypes, this may contribute to the various disease outcomes caused by H. pylori infection in different individuals.

Background: New Delhi metallo-b-lactamase-1 (NDM-1) is a relatively recent carbapenemase enzyme that inactivates all b-lactam antibiotics with the exception of aztreonam. This study aims to ascertain the baseline prevalence and antibiotic susceptibility patterns of NDM-1-producing Enterobacteriaceae in a tertiary medical center in Malaysia. Methods: Over a period of one year, all Enterobacteriaceae isolates from all clinical specimens with reduced susceptibility to at least one carbapenem and resistance to at least one third generation cephalosporin were subjected to antibiotic susceptibility testing by disk diffusion and molecular detection of the NDM-1 gene by single-target PCR followed by gel electrophoresis. Results: A total of 13,098 Enterobacteriaceae isolates were screened and 63 (0.48%) had reduced susceptibility to at least one carbapenem. Of this 63, 18 (29%) were NDM-1-positive. Of this 18, 16 (89.0%) were Klebsiella pneumoniae, one (5.5%) was Escherichia coli and one (5.5%) was Klebsiella ornithinolytica. Reduced susceptibility to at least one aminoglycoside was seen in 17 (94%) of the NDM-1-positive isolates. All 18 (100%) had reduced susceptibility to ertapenem and were resistant to all the second and third generation cephalosporin antibiotics tested. Conclusion: The prevalence of NDM-1-producing Enterobacteriaceae among all the Enterobacteriaceae isolates in our institution is low (0.14%) and screening for the NDM-1 gene is best performed using ertapenem-impregnated disks.
Molecular Detection Of The New Delhi Metallo-B-Lactamase-1 Gene In Enterobacteriaceae Isolates In A Tertiary Medical Centre

The multiracial population in Malaysia has lived together for almost a century, however, the risk ofgastric cancer among them varies. This study aimed to determine the distribution of different gastricadenocarcinoma subtypes and Helicobacter pylori infection status among gastric adenocarcinomapatients. Patients with gastric adenocarcinoma were enrolled from November 2013 to June 2015.Blood samples were collected for detection of H. pylori using ELISA method. Gastric adenocarcinomacases were more prevalent in the Chinese (52.8%), followed by the Malays (41.7%) and leastprevalent in the Indians (5.6%). Gastric adenocarcinoma located in the cardia was significantly moreprevalent in the Malays (66.7%) compared to the Chinese (26.3%), whereas non-cardia cancer wasdiagnosed more in the Chinese (73.7%) compared to the Malays (33.3%) [P = 0.019; OR = 5.6, 95CI: 1.27 to 24.64]. The Malays also had significantly higher prevalence of gastric tumour locatedat the cardia or fundus than other gastric sites compared to the Chinese (P = 0.002; OR: 11.2, 95%CI: 2.2 to 56.9). Among the cardia gastric cancer patients, 55.6% of the Malays showed intestinalhistological subtype, whereas all the Chinese had the diffuse subtype. More than half of the patients(55.3%) with gastric adenocarcinoma were positive for H. pylori infection and among them, 66.7%were Chinese patients. The risk of gastric adenocarcinoma in our population is different amongethnicities. Further studies on host factors are needed as it might play an important role in gastriccancer susceptibility in our population.

Abstract An epsilometer-test method was used to determine MIC values of several antibiotics against 29 Helicobacter pylori isolated from gastric antrum of dyspepsia patients. Isolates with resistance towards antibiotics were 6.9% -65.5% but these were tetracycline-sensitive. Eight isolates showed multi-resistance towards two antimicrobial agents. The high resistance strains towards metronidazole is alarming.