Comparison of Tests To Detect Oxacillin Resistance in Staphylococcus intermedius , Staphylococcus schleiferi , and Staphylococcus aureus Isolates from Canine Hosts

Abstract

Multiple tests were compared to the reference standard PBP2a latex agglutination test for detection of mecA-mediated oxacillin resistance in canine staphylococci. Cefoxitin disk diffusion, using breakpoints for human isolates of coagulase-negative Staphylococcus spp., had low sensitivity for detection of oxacillin resistance in members of the Staphylococcus intermedius group.

Prevalence and in vitro susceptibility of methicillin-resistant Staphylococcus pseudintermedius (MRSP) from skin and nostrils of dogs with superficial pyoderma

“…Therefore, both tests can be used safely to determine methicillin resistance in dogs. These results are in agreement with those found in the USA (Bemis et al 2006) However, such results differ from those obtained in Brazil (Bourguignon 2012), which did not show to have positive correlation between the tests.…”

Evaluation of Clinical Laboratory Standards Institute Interpretive Criteria for Methicillin-Resistant Staphylococcus Pseudintermedius Isolated from Dogs

“…In contrast, cefoxitin disk diffusion has been reported to be 84.6-100% sensitive and 87.5-100% specific for mecA-positive and -negative human origin S. aureus, respectively. 1,4 In a previous study, 3 cefoxitin disk diffusion was 100% specific in 74 isolates with CNS interpretive criteria. Specificity could not be assessed in the work presented here because mecA-negative isolates were not evaluated.…”

Description of Methicillin-resistant Staphylococcus pseudintermedius from canine pyoderma in Minas Gerais state, Brazil

“…The discrepancy between the presence of mecA and the absence of corresponding oxacillin resistance has been previously noted in other studies (Bemis et al, 2006;Schissler et al, 2009;Feng et al, 2012). The presence of mecA positive S. pseudintermedius and S. aureus isolates that were susceptible to oxacillin was previously described (Forbes et al, 2008;Feng et al, 2012).…”

“…This protein is expressed either homogeneously, which is easily detected with standard testing methods, or heterogeneously, which is more difficult to detect with those methods, since only a fraction of the population expresses the resistance phenotype (Bemis et al, 2006). This study aimed to characterize S. pseudintermedius isolates from canine pyoderma by phenotypic and genotypic methods, and evaluate their resistance profiles to antimicrobials and the presence of the mecA gene.…”