Highly Resistant Yersinia enterocolitica Isolated from Dairy Based Foods in Lebanon

Abstract

Yersinia is small rod shaped, gram negative coccibacilli known as a food borne pathogen that may cause intestinal and systemic diseases known as yersiniosis. It has been reported that it may be transmitted by eating contaminated dairy foods.  This study aims at evaluating the presence of Yersinia enterocolitica in Lebanese three dairy based foods which include Kishk, Shankleesh and Baladi cheese and reporting their susceptibilities to commonly used antimicrobial agents. In total, sixteen Y. enterocolitica isolates were recovered and subjected to relevant biochemical tests and finally identified by API system.  Eleven of those isolates were from Baladi cheese, three from Shankleesh and two from Kishk. The API results confirmed their identity, and were then subjected for susceptibility testing against: chloramphenicol (30µg), trimethoprim/ sulfamethoxazole (1.25µg+23.75µg), gentamicin (10µg), ciprofloxacin (5µg), nalidixic acid (30µg), Kanamycin (30µg) and streptomycin (10µg). Surprisingly, all the tested Y. enterocolitica isolates showed high rates of resistance to all the antimicrobials used with highest resistance to kanamycin (81.2%) and streptomycin (87.5%). The data showed that the antimicrobial resistance levels exceeded by far all the levels reported elsewhere. Based on the data, it may be concluded that dairy based foods in Lebanon, especially cheese that is prepared under unaccepted conditions, not abiding by proper hygienic practices. This might be the cause of a public health hazard, as cheese might act as a potential vehicle for the transmission of many resistant bacterial pathogens to human consumers. For this reason, it is advisable to use strict conditions in cheese processing to reduce the hazards that may be involved with its consumption