A highly conservedmecC-encoding SCCmectype XI in a bovine isolate of methicillin-resistantStaphylococcus xylosus

Abstract

The discovery of MRSA encoding the mecA variant mecC from dairy cattle and humans, 1 and then subsequently from a diverse range of other host species, 2,3 has raised questions over the origin and epidemiology of this resistance determinant. In addition to Staphylococcus aureus, mecC has been described in other staphylococci, namely Staphylococcus xylosus, 4 Staphylococcus sciuri, 5 Staphylococcus stepanovicii, 6,7 Staphylococcus saprophyticus 8,9 and Staphylococcus edaphicus, 10 all of which are methicillin resistant with the exception of S. xylosus. The mecC of S. aureus is encoded within an SCCmec type XI element, carrying a class E mec gene complex associated with the genes ccrA1 and ccrB3, corresponding to a type 8 ccr gene complex. 11 This is not the situation in the other mecC-positive staphylococci reported to date. In these species, although mecC is part of a conserved class E mec gene complex inserted into the orfX region, the neighbouring sequences vary considerably between the different species with little homology to SCCmec type XI or any other known SCCmec type and do not always contain ccr gene complexes. 4-6,10 Herein we describe an S. xylosus isolate, 47-83, from bulk tank milk collected in Sussex, England in 2013, which encodes mecC within a highly conserved SCCmec type XI. The isolate was found during the screening of bulk tank milk for MRSA, as described previously. 12 It grew on MRSA Brilliance MRSA 2 agar (Oxoid, Basingstoke, UK) and was resistant to oxacillin and cefoxitin by disc diffusion. Susceptibility testing of 47-83 using the VITEK 2 card AST-P634 found it to be susceptible to chloramphenicol, ciprofloxacin, clindamycin, daptomycin, erythromycin, gentamicin, linezolid, mupirocin, rifampicin, teicoplanin, tetracycline, tigecycline, trimethoprim and vancomycin,

Characterization of mecC gene-carrying coagulase-negative Staphylococcus spp. isolated from various animals

“…This frameshift mutation was also observed in S. xylosus AD10b analysed in the present study, which may explain the low oxacillin MIC of this strain and its inability to grow on oxacillin screening agar. Very recently, another S. xylosus (strain 47-83) was detected(MacFadyen et al, 2018a), which encodes an intact prototype mecC as the one previously found in LGA251. So far, mecC-positive S. xylosus has never been isolated from brown rat (Rattus norvegicus).…”

Nocturnal Birds of Prey as Carriers of Staphylococcus aureus and Other Staphylococci: Diversity, Antimicrobial Resistance and Clonal Lineages

“…In addition to the mec C gene, this isolate also harbored bla Z-SCC mec XI, which is a bla Z allotype associated with SCC mec XI as previously reported [ 13 ]. In turn, the SCCmec XI is also associated with the mecC gene [ 41 ]. In addition to the hla and hlb virulence genes, the mec C-MRSA isolate also carried the etd 2 gene, which is an exfoliative toxin that is a homologue to etd .…”

Distribution and Clonal Diversity of Staphylococcus aureus and Other Staphylococci in Surface Waters: Detection of ST425-t742 and ST130-t843 mecC-Positive MRSA Strains

“…However, other genes, mec B, mec C and mec D, have been recently reported [ 22 , 23 , 24 ]. mec C is part of the SCC mec type XI and it has been mainly reported associated with S. aureus and CoNS in wildlife and environmental samples [ 25 , 26 , 27 ]. Monoresistance and multiresistance have been reported among both S. aureus and CoNS isolated from the environment, in particular in the aquatic ecosystems [ 21 ].…”