| Summary: | <i>Enterococcus</i> spp. are opportunistic pathogens of both humans and animals characterized by high resistance to antimicrobials. Dogs could be intestinal carriers or suffer from <i>Enterococcus</i> infections, mainly urinary tract infections (UTIs). This study aimed to analyze and compare <i>Enterococcus</i> spp. isolated from healthy dog stools and sick dog urine. Overall, 51 isolates (29 from stools and 22 from UTI) were characterized at species level and tested for antimicrobial resistance, biofilm production and presence of resistance and virulence genes. <i>E. faecium</i> and <i>E. faecalis</i> resulted as equally distributed in stools samples, while <i>E. faecalis</i> predominated among UTI isolates. HLAR phenotype was detected in 47.1% isolates; 64.7% isolates were resistant to ampicillin (47.1% with a MIC ≥ 64 µg/mL). High levels of resistance were recorded for fluoroquinolones (enrofloxacin 74.5%, ciprofloxacin 66.7%), clindamycin (84.3%), tetracycline (78.4%) and quinupristin–dalfopristin (78.4%). No vancomycin resistant strains were detected. All but one isolate were multidrug-resistant. Most detected resistance genes were <i>tetM</i> (70.5%), <i>pbp4</i> (52.9%) and aph(3′)-IIIa (39.2%). All isolates were able to produce biofilm, but isolates from UTIs and belonging to <i>E. faecalis</i> more frequently resulted in strong biofilm producers. Most detected virulence genes were <i>asa1</i> (52.9%), <i>gelE</i> (41.2%), <i>cylA</i> (37.3%) and <i>esp</i> (35.3%); all of them resulted as more frequently associated to <i>E. faecalis</i>. No particular differences emerged between isolates from feces and UTI, considering all evaluated aspects. Our results confirm pet dogs as carriers of multidrug-resistant enterococci; stool microflora could be considered as the most probable source of enterococcal UTI and <i>E. faecalis</i> carried by dogs seems to be more virulent than <i>E. faecium</i>, justifying its more frequent involvement in urinary tract infections.
|
|---|