Antimicrobial resistance and population structure of Staphylococcus epidermidis recovered from animals and humans

While Staphylococcus epidermidis, as part of the commensal flora, is a well-known human opportunistic pathogen, only little is known about the genetic relatedness of S epidermidis carriage isolates from animal and human origin This study aimed to compare S epidermidis recovered from livestock, livestock-farmers and humans associated with the hospital environment A total of 193 S epidermidis isolates from three populations [animals ( n= 33), farmers ( n= 86) and hospital-associated ( n= 74)] were characterized by broth microdilution antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCC mec) typing, pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) The overall S epidermidis nasal colonization rate was low in animals (1-9%) but high among farmers (75%) High levels of multi-resistance were found in all populations Tetracycline resistance was high in animal and farmer isolates; resistance to erythromycin, clindamycin and trimethoprim was high in animal and hospital-associated isolates Methicillin-resistant S epidermidis - MRSE isolates were found in all collections, with 22 (67%) MRSE in animals, 44 (51%) MRSE in farmers and 42 (57%) MRSE associated with the hospital-setting Known SCC mec types and variants were detected in 79% of MRSE; the rest were non-typeable cassettes In total 79 PFGE-types were found, of which 22 were shared between livestock, farmers and the hospital settings Clonal complex 2 was predominant in all three populations and most STs corresponded to types previously observed in community and nosocomial S epidermidis populations S epidermidis isolates from livestock, farmers and hospital-setting showed a high level of diversity, but some clones can be found in humans as well as in animals. © 2015 Elsevier B.V.