Susceptibility of bacteria of the Enterococcus genus isolated on Lithuanian poultry farms

Abstract

ABSTRACT:The aim of this study was to test and analyse the antimicrobial susceptibility of Enterococcus isolates from Lithuanian poultry farms. Investigations were carried out during the years 2008-2009. The sampling sites, located all over the country, included eight poultry farms of large capacity. All samples were collected from broilers. Enterococcus spp. were isolated from intestines immediately after slaughtering. A total of 160 samples were collected, 20 samples from each farm. The MICs (Minimum Inhibitory Concentrations) of eleven antimicrobial agents were determined for each of the isolates using the broth microdilution method with specific microtitre plate panels (Trek Diagnostic Systems, Inc.). Susceptibility according to clinical breakpoints of chloramphenicol, linezolid, erythromycin, penicillin, quinupristin/dalfopristin, tetracycline, vancomycin, ciprofloxacin and nitrofurantoin was evaluated. One hundred and forty seven samples (92%) from a total of 160 tested samples were positive for Enterococcus spp., however, only 74 strains were selected as non-duplicate isolates. The most predominant species were identified as E. faecium (38%), E. faecalis (17.5%), E. gallinarum (12%) and E. casseliflavus (12%). The most frequent resistance properties were resistances to tetracycline (75.6%), erythromycin (56.8%) and ciprofloxacin (41.9%). No strains resistant to vancomycin and linezolid were found. High percentages of susceptibility to chloramphenicol (82.4%) and penicillin (71.6%) were also observed. A high MIC of tigecycline (≥ 1 mg/l) to 12.2% of enterococci was determined during this study. 44.6% of tested strains had a high MIC (≥ 64 mg/l) to tylosin. There was no significant correlation found between resistances of different species to different antimicrobial agents in vitro.

Prevalence and antibiotic resistance of Enterococcus strains isolated from poultry

“…Enterococcus faecium and E. faecalis are usually the most prevalent enterococcal species among isolates recovered from environmental samples such as poultry faeces/manure, feed, water and air (Yoshimura et al, 2000;Ruzauskas et al, 2009;Ali et al, 2013;Furtula et al, 2013), but very few data are available on enterococci from internal organs of healthy or diseased poultry (Tankson et al, 2002;Maasjost et al, 2015). In contrast to these data, the results obtained in this study indicate that E. faecalis accounted for the highest percentage of enterococci isolated from the internal organs of poultry, followed by E. faecium.…”

“…Our results are similar to the resistance profiles of lincomycin, tetracycline, penicillin, ciprofloxacin and tylosin in Enterococcus isolates from the environment of broiler and/or layer farms (Ruzauskas et al, 2009;Diarra et al, 2010;Šeputienė et al, 2012;Furtula et al, 2013). Moreover, in Poland, Różańska et al (2015) noted that the highest number of E. faecalis strains isolated from poultry meat were resistant to lincomycin (24 strains; 100%), the second-highest resistance was to tetracycline (21 strains; 87.5%), followed by tylosin (16 strains; 66.7%).…”

Antimicrobial Resistance in Enterococcus spp. Isolated from Environmental Samples in an Area of Intensive Poultry Production

“…Taken together, these results suggest similarities around the globe. Interestingly, high resistance to tetracycline (75.6%), erythromycin (56.8%) and ciprofloxacin (41.9%) were reported in a previous study of Enterococcus isolated from poultry intestines immediately after slaughtering [39]. However, analysis of changes in prevalence and patterns of antimicrobial resistance among Enterococcus spp.…”

Prevalence and Antibiotic Susceptibility of Escherichia coli and Salmonella spp. isolated from milk of zero grazed cows in Arusha City

“…Some studies in Tanzania and Nigeria reported that, chloramphenicol is irrationally used in animals as evidenced by the presence of its residues in poultry and poultry products (Nonga et al, 2010;Darwish et al, 2013). However, it may be due to transfer of resistant genes as a result of cross contamination between humans, animals and the environment (Bischoff et al, 2005;Salehi and Bonab, 2006) or use of other antibiotics belonging to aphenicol group (Ruzauskas et al, 2009). The susceptibility pattern of E. coli from all the sampling sites is summarized in the Table 2.…”