Molecular detection of blaCTX-M gene to predict phenotypic cephalosporin resistance and clinical outcome of Escherichia coli bloodstream infections in Vietnam.

BACKGROUND: Blood stream infections (BSI) caused by Extended Spectrum Beta-Lactamases (ESBLs) producing Enterobacteriaceae is a clinical challenge leading to high mortality, especially in developing countries. In this study, we sought to describe the epidemiology of ESBL-producing Escherichia coli strains isolated from Vietnamese individuals with BSI, to investigate the concordance of genotypic-phenotypic resistance, and clinical outcome of ESBL E. coli BSI. METHODS: A total of 459 hospitalized patients with BSI were screened between October 2014 and May 2016. 115 E. coli strains from 115 BSI patients were isolated and tested for antibiotic resistance using the VITEK®2 system. The ESBL phenotype was determined by double disk diffusion method following the guideline of Clinical and Laboratory Standards Institute. Screening for beta-lactamase (ESBL and carbapenemase) genes was performed using a multiplex-PCR assay. RESULTS: 58% (67/115) of the E. coli strains were ESBL-producers and all were susceptible to both imipenem and meropenem. Resistance to third-generation cephalosporin was common, 70% (81/115) were cefotaxime-resistant and 45% (52/115) were ceftazidime-resistant. blaCTX-M was the most common ESBL gene detected (70%; 80/115) The sensitivity and specificity of blaCTX-M-detection to predict the ESBL phenotype was 87% (76-93% 95% CI) and 54% (39-48% 95% CI), respectively. 28%% (22/80) of blaCTX-M were classified as non-ESBL producers by phenotypic testing for ESBL production. The detection of blaCTX-M in ESBL-negative E. coli BSI was associated with fatal clinical outcome (27%; 6/22 versus 8%; 2/26, p = 0.07). CONCLUSION: A high prevalence of ESBL-producing E. coli isolates harbouring blaCTX-M was observed in BSI patients in Vietnam. The genotypic detection of blaCTX-M may have added benefit in optimizing and guiding empirical antibiotic therapy of E. coli BSI to improve clinical outcome.

High Hepatitis E virus (HEV) Positivity Among Domestic Pigs and Risk of HEV Infection of Individuals Occupationally Exposed to Pigs and Pork Meat in Hanoi, Vietnam.

BACKGROUND: Hepatitis E virus (HEV) infection can occur through consumption of undercooked pork meat or exposure to animal feces. Because there are scarce data only in developing countries, we assessed whether pigs might be a potential source of human HEV infections in Vietnam. In addition, we determined anti-HEV seroprevalences in the general population and in individuals professionally exposed to pigs and pork meat. METHODS: The study took place in Hanoi, Vietnam. Liver tissues from domestic pigs (n = 210) and serum samples obtained from individuals occupationally exposed to pigs and pork meat (n = 283) and from unexposed healthy controls (n = 168) were screened for HEV-ribonucleic acid (RNA) by reverse-transcription polymerase chain reaction. The exposed group was divided into pork meat vendors (n = 81), pig farmers (n = 96), and slaughterers (n = 106). Serum samples were subjected to HEV immunoglobulin (Ig)G and IgM enzyme-linked immunosorbent assays. The HEV genotypes were assessed by direct sequencing, followed by phylogenetic analyses. RESULTS: Hepatitis E virus seroprevalence was higher among persons occupationally exposed to pigs/pork meat compared with unexposed individuals (anti-HEV IgM 11% vs 6%, P = .07; anti-HEV IgG 53% vs 31%, P < .0001). Positivity of anti-HEV IgG among slaughterhouse staff was 66%, followed by 51% in pig-farmers and 38% in pork meat vendors (P = .00073). A similar trend was observed for IgM positivity. Of the pig liver tissues, 26 of 210 (12.4%) were positive for HEV-RNA and assessed to be HEV genotype 3. CONCLUSIONS: Hepatitis E virus circulates in domestic pigs in Hanoi and constitutes a permanent zoonotic disease risk. The high HEV seroprevalence among occupationally exposed individuals indicates an associated risk of HEV infection.