AUTHOR=Moreno-Grúa Elena , Pérez-Fuentes Sara , Muñoz-Silvestre Asunción , Viana David , Fernández-Ros Ana B. , Sanz-Tejero Celia , Corpa Juan M. , Selva Laura 

TITLE=Characterization of Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates Obtained From Commercial Rabbitries Located in the Iberian Peninsula

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01812

DOI=10.3389/fmicb.2018.01812

ISSN=1664-302X

ABSTRACT=<p>Infections caused by methicillin-resistant <italic>Staphylococcus aureus</italic> (MRSA) have been a growing problem in human medicine since the 1960s, and more recently in veterinary medicine with the appearance of livestock-associated MRSA (LA-MRSA). Nevertheless, information about the presence of MRSA in rabbits is quite scarce since only one LA-MRSA identification has been previously reported. The present study aimed to determine genotypic characterization by verifying the presence of resistance determinants, virulence, and toxin genes of different <italic>S. aureus</italic> strains that cause lesions in rabbits, and their phenotypic traits based on the antimicrobial susceptibility profile. The analysis of 240 <italic>S. aureus</italic> isolates obtained from different lesion types collected from 89 Spanish and Portuguese rabbit commercial farms in the last 4 years (2014–2017) was performed. The methicillin-resistant gene <italic>mec</italic>A was found in 11.25% of the studied isolates (27 of 240) from 19 farms (13 Spanish and 6 Portuguese). Staphylococcal cassette chromosome <italic>mec</italic> (SCC<italic>mec</italic>) typing predominantly revealed type III (<italic>n</italic> = 15). Additionally, three MRSA isolates carrying the <italic>mec</italic>C gen were detected in samples from three different farms (two Spanish and one Portuguese). None of the 30 MRSA isolates was <italic>PVL</italic>-positive or <italic>tst</italic>-positive. After the multilocus sequence typing (MLST) procedure, 16 belonged to ST2855, 6 to ST146, 6 to ST398, and 2 ST4774. No ST121 isolate was <italic>mec</italic>-positive. ST398 and ST4774 isolates lacked the immune-evasion-cluster (IEC) genes. ST2855 strains were associated with the presence only of the <italic>sak</italic> gene, and ST146 isolates were ascribed to IEC type E. Therefore, this is the first description of LA-MRSA from rabbits belonging to ST2855. Interestingly, one ST2855 and two ST4774 isolates were <italic>mec</italic>C-positive, which could act as a <italic>mec</italic>C-MRSA reservoir. More studies are needed to further characterize these isolates and their relationship with humans and other animal species.</p>