Affiliation:
1. Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Zurich, Switzerland
2. Cantonal Office of Consumer Protection Aargau, Aarau, Switzerland
Abstract
ABSTRACT
To examine to what extent fresh vegetables imported into Switzerland represent carriers of extended-spectrum-β-lactamase (ESBL)-producing
Enterobacteriaceae
, 169 samples of different types of fresh vegetables imported into Switzerland from the Dominican Republic, India, Thailand, and Vietnam were analyzed. Overall, 25.4% of the vegetable samples yielded one or more ESBL-producing
Enterobacteriaceae
, 78.3% of which were multidrug resistant. Sixty isolates were obtained:
Escherichia coli
, 26;
Klebsiella pneumoniae
, 26;
Enterobacter cloacae
, 6;
Enterobacter aerogenes
, 1; and
Cronobacter sakazakii
, 1. We found 29 isolates producing CTX-M-15, 8 producing CTX-M-14, 7 producing CTX-M-55, 3 producing CTX-M-65, 1 each producing CTX-M-1, CTX-M-3, CTX-M-27, and CTX-M-63, 5 producing SHV-2, 3 producing SHV-12, and 1 producing SHV-2a. Four of the
E. coli
isolates belonged to epidemiologically important clones: CTX-M-15-producing B2:ST131 (1 isolate), D:ST405 (1 isolate), and D:ST38 (2 isolates). One of the D:ST38 isolates belonged to the extraintestinal enteroaggregative
E. coli
(EAEC) D:ST38 lineage. Two of the
K. pneumoniae
isolates belonged to the epidemic clones sequence type 15 (ST15) and ST147. The occurrence of antibiotic-resistant pathogenic and commensal
Enterobacteriaceae
in imported agricultural foodstuffs constitutes a source of ESBL genes and a concern for food safety.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology