AUTHOR=Abdullahi Idris Nasir , Lozano Carmen , Zarazaga Myriam , Saidenberg Andre Becker Simoes , Stegger Marc , Torres Carmen 

TITLE=Clonal relatedness of coagulase-positive staphylococci among healthy dogs and dog-owners in Spain. Detection of multidrug-resistant-MSSA-CC398 and novel linezolid-resistant-MRSA-CC5

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1121564

DOI=10.3389/fmicb.2023.1121564

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>Nasal carriage of coagulase-positive staphylococci (CoPS) in healthy dogs could indicate increased risks of colonization for in-contact people or vice versa. This study determined the nasal carriage rate of CoPS among healthy dogs and in-contact people, their genotypic characteristics and phylogenetic relatedness.</p></sec><sec><title>Methods</title><p>Nasal samples were collected from 27 households (34 dogs and 41 humans) in Spain. Staphylococci were identified by MALDI-TOF-MS, their antimicrobial resistance (AMR) genes and <italic>spa</italic>-types were tested by PCR/sequencing. The relatedness of CoPS from the same households was assessed by core genome single nucleotide polymorphisms (SNPs) analyses.</p></sec><sec><title>Results</title><p><italic>Staphylococcus aureus</italic> carriage was found in 34.1% of humans (including one methicillin-resistant <italic>S. aureus</italic> MRSA-CC5-t2220-SCC<italic>mec</italic> type-IV2B) and 5.9% of dogs; <italic>Staphylococcus pseudintermedius</italic> in 2.4% of humans and 32.4% of dogs; while <italic>Staphylococcus coagulans</italic> was only detected in dogs (5.4%). Remarkably, one human co-carried <italic>S. aureus</italic>/<italic>S. pseudintermedius</italic>, while a dog co-carried the three CoPS species. Household density was significantly associated with <italic>S. pseudintermedius</italic> carriage in households with &gt; than 1 dog and &gt;than 1 human (OR = 18.10, 95% CI: 1.24–260.93, <italic>p</italic> = 0.034). Closely related (&lt;15 SNPs) <italic>S. aureus</italic> or <italic>S. pseudintermedius</italic> were found in humans or dogs in three households. About 56.3% <italic>S. aureus</italic> carriers (dog or human) harboured diverse within-host <italic>spa</italic>-types or AMR genotypes. Ten clonal complexes (CCs) were detected among the <italic>S. aureus</italic>, of which methicillin-susceptible <italic>S. aureus</italic>-CC398-IEC-type C (t1451 and t571) was the most frequent, but exclusive to humans. <italic>S. aureus</italic> and <italic>S. pseudintermedius</italic> isolates harboured resistance genes or mutations associated to 9 classes of antimicrobials including linezolid (G2261A &amp; T1584A point mutations in 23S rDNA). The <italic>S. coagulans</italic> isolates were susceptible to all antimicrobials. Most of the <italic>S. pseudintermedius</italic> carried <italic>lukS/F-I, siet,</italic> and <italic>sient</italic> genes, and all <italic>S. aureus</italic> were negative for <italic>lukS/F</italic>-PV<italic>, tst-1, eta</italic> and <italic>etb</italic> genes.</p></sec><sec><title>Discussion</title><p>Clonally related human-to-human MSSA and dog-to-human MSSP were found. The detection of the MSSA-CC398 clade highlights the need for its continuous surveillance from One Health perspective.</p></sec>