ANTIMICROBIAL RESISTANCE OF ENTEROCOCCUS SPP. SPREAD IN POULTRY PRODUCTS IN LITHUANIA

The objective of the study was to evaluate the antimicrobial susceptibility of enterococci spread in raw products of poultry origin intended for human consumption in Lithuania. Samples were obtained from retail markets all over the country. Fifty-eight samples (83%) from a total of 70 tested were positive for Enterococcus spp. Enterococcus faecium (36.2%), E. faecalis (29.3%) and E. hirae (17.2%) were the most prevalent species. Susceptibility testing was based on a microdilution test. Results were interpreted according to clinical breakpoints. The most frequent resistance was demonstrated to tetracycline (84.5%), tylosin (64.5%), erythromycin (63.8%) and ciprofloxacin (36.2%). No resistant strains were found to vancomycin, linezolid and tigecycline. Susceptibility to antimicrobials varied among different species of enterococci. E. faecalis demonstrated more frequent resistance to tylosin, E. hirae - to nitrofuranes. E. faecium was more frequently resistant to penicillin and tetracycline. Both E. faecium and E. hirae demonstrated more frequent resistance to fluoroquinolones than E. faecalis. Susceptibility to other antimicrobials statistically was unreliable between these species of enterococci. PRACTICAL APPLICATIONS Enterococci are widely spread in raw poultry products. Antimicrobial resistance is highly important for antimicrobials that are used in human medicine. The results demonstrate the frequent resistance of enterococci to tetracycline, macrolides and fluoroquinolones (ciprofloxacin). This could be associated with the intensive and extensive usage of these antimicrobials within the country. Hygienic measures in raw food-production should be strongly enforced. Personal hygiene during marketing is also very important since resistant bacteria could easily spread among salespersons and consumers. Commensal bacteria should be used as indicators for antimicrobial resistance in food control operations.