Occurrence and characteristics of extended spectrum beta-lactamases-producing enterobacteriaceae from foods of animal origin

Abstract

Presence of extended spectrum beta-lactamases (ESBL) in bacteria is a growing health concern of global significance. The local, regional, national, and international epidemiologicalstudies for extended spectrum beta-lactamases-producing Enterobacteriaceae and theirencoding genes in foods are still incomplete. The objective of this study was to determine theoccurrence of extended spectrum beta-lactamases-producing Enterobacteriaceae and thecharacteristics of their encoding genes from a total of 250 samples of various foods of animal-origin (100 raw chicken meat, 100 raw cow milk, and 50 raw cow milk cheese) sold in Turkey.Overall, 55 isolates were positive as extended spectrum beta-lactamases-producing Entero-bacteriaceae. The most prevalent extended spectrum beta-lactamases-producing strainwere identified as Escherichia coli (80%), followed by Enterobacter cloacae (9.1%), Citrobacterbraakii (5.5%), Klebsiella pneumoniae (3.6%), and Citrobacter werkmanii (1.8%) by Vitek® MS. Thesimultaneous production of extended spectrum beta-lactamases and AmpC was detected infive isolates (9.1%) in E. coli (80%) and E. cloacae (20%). The frequency rates of blaTEM, blaCTX-M,and blaSHV were 96.4%, 53.7%, and 34.5%, respectively. The co-existence of bla-genes wasobserved in 82% of extended spectrum beta-lactamases producers with a distribution of blaTEM & blaCTX-M(52.7%), blaTEM & blaSHV(20%), blaTEM & blaCTX-M & blaSHV(12.7%), and blaSHV& blaCTX-M(1.8%). The most prevalent variant of blaCTX-Mclusters was defined as blaCTX-M-1(97.2%), followed by blaCTX-M-8(2.8%). In summary, the analysed foods were found to be pos-ing a health risk for Turkish consumers due to contamination by Enterobacteriaceae with adiversity of extended spectrum beta-lactamases encoding genes.