Adhesin Genes And Biofilm Formation Among Pediatricstaphylococcus Aureus Isolates From Implant-Associated Infections

Background Microbial surface component recognizing adhesive matrix molecules (MSCRAMMs) facilitateStaphylococcus aureusadherence to host tissue. We hypothesized thatS.aureusisolates from implant-associated infections (IAIs) would differ in MSCRAMM profile and biofilm formationin vitrocompared to skin and soft tissue infection (SSTI) isolates. Methods Pediatric patients and their isolates were identified retrospectively. IAI and SSTI isolates were matched (1:4). Pulsed field gel electrophoresis was performed to group isolates as USA300 vs. non-USA300. Whole genome sequencing was performed and raw sequence data were interrogated for presence of MSCRAMMs (clfA,clfB,cna,ebh,efb,fnbpA,fnbpB,isdA,isdB,sdrC,sdrD,sdrE), biofilm-associated (icaA,D,B,C), and Panton-Valentine leukocidin (lukSF-PV) genes, accessory gene regulator group, and multilocus sequence types.In vitrobiofilm formation was assessed for 47 IAI and 47 SSTI isolates using a microtiter plate assay. Conditional logistic regression was performed for analysis of matched data (STATA11, College Station, TX). Results Forty-seven IAI and 188 SSTI isolates were studied. IAI isolates were more often methicillin susceptibleS.aureusand non-USA300 vs. SSTI isolates [34 (72%) vs. 79 (42%), p = 0.001 and 38 (81%) vs. 57 (30%) p <0.001, respectively]. Greater than 98% of isolates carriedclfA,clfB,efb,isdA,isdB, andicaA,D,B,Cwhilecnawas more frequently found among IAI vs. SSTI isolates (p = 0.003). Most isolates were strong biofilm producers. Conclusions S.aureusIAI isolates were significantly more likely to be MSSA and non-USA300 than SSTI isolates. Carriage of MSCRAMMs and biofilm formation did not differ significantly between isolates. Evaluation of genetic polymorphisms and gene expression profiles are needed to further delineate the role of adhesins in the pathogenesis of IAIs.