Characteristics of Extended-Spectrum β-Lactamase-Producing Escherichia coli in Retail Meats and Shrimp at a Local Market in Vietnam

Abstract

Background: Contamination of food with multiantibiotic-resistant bacteria, particularly extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, is considered a potential source for the wide dissemination of ESBL-producing bacteria in communities. However, little is known about the extent of contamination of food with ESBL-producing bacteria in Vietnam.

Objective: This study was conducted to assess the characteristics of ESBL-producing Escherichia coli isolated from retail meats and shrimp in Nha Trang, Vietnam.

Materials and methods: A total of 350 food samples (poultry [n=143], pork [n=147], and shrimp [n=60]) were purchased in July and November 2013 from a local market. ESBL-producing E. coli were isolated, and ESBL genotypes, phylogenetic groups, and antibiotic resistance profiles were determined.

Results: The prevalence of ESBL-producing E. coli in retail foods was 40.6%. β-Lactamase-encoding genes of the CTX-M-1 (50.7%), CTX-M-9 (41.5%), TEM (59.9%), and SHV (2.8%) groups were detected singly or in combination. The percentages of single ESBL isolates harboring CTX-M-1 or -9 plus TEM groups were 35.2% and 16.2%, respectively. B1 was the most prevalent phylogroup in ESBL isolates from pork (44.7%), poultry (55.9%), and shrimp (72.7%). B2 was the least prevalent (4.2% and 4.8% for pork and poultry isolates, respectively). The prevalence of multidrug resistance (MDR; resistance to ≥ 3 antimicrobial groups) in ESBL-producing E. coli isolated from food was 85.9%.

Discussion and conclusions: This is the first report of the characteristics of ESBL-producing E. coli in retail foods in a local city in Vietnam. Our findings indicate that retail foods are contaminated with ESBL-producing E. coli, of which many were MDR. Further monitoring and public health efforts targeting food administration are needed to control the spread of ESBL-producing bacteria in communities.