ANTIMICROBIAL RESISTANCE OF ENTEROCOCCUS SPP. ISOLATED FROM FISH, RTE FISH PRODUCTS AND THE ENVIRONMENT OF FISH MARKETS IN NORTHERN GREECE

摘要

Enterococci are important causative agents for hospital infections. E. faecalis and E. faecium are the predominant species that cause infections in Europe and USA. Enterococcus spp. bacteria posses a broad spectrum of natural and acquired antibiotic resistance. Vancomycin resistant enterococci have emerged as a major problem that has progressively increased over the last decade. Fish and fish products are potentially contamination sources for humans and knowledge on this issue is limited. The aim of this study was to examine the antimicrobial resistance of 106 strains of Enterococcus spp. isolated from 390 samples taken from fish, ready-to-eat (RTE) fish products and the environment of fish markets in Northern Greece. Antimicrobial resistance testing against antibiotics commonly used in Greek hospitals was performed by the methods of minimal inhibitory concentration (MIC) and disk diffusion according to the guidelines of CLSI (2008). One hundred and six strains of Enterococcus out of 390 specimens (26.4%) were isolated and examined. Predominant species were E. faecium (16.2%) and E. faecalis (5.4%). E. faecium isolates presented high rates of antimicrobial resistance to clindamycin (62%), gentamicin (29%) and rifabin (28%), while E. faecalis isolates were resistant to clindamycin (92%), gentamicin (12%), rifabin (10%) and penicillin (10%). Two strains presented intermediate resistance to vancomycin, but genes vanA, vanB, vanC1 and vanC2/3 vieiz detected by PCR. Results indicate that Enterococcus spp. commonly contaminate fish and fish products and that dissimilarities in antimicrobial resistance patterns among enterococci species are common. Attention has to be paid for compliance with codes of good practice in the processing and transport of fish in order to ensure the health of workers and consumers.