Carriage of Bacteria Antagonistic Towards Staphylococcus intermedius on Canine Skin and Mucosal Surfaces

Abstract— Antagonism against Staphylococcus intermedius was investigated amongst bacteria isolated from skin and mucosae of (1) 15 dogs with pyoderma and (2) 42 healthy dogs, including household pets, laboratory beagles and guide dogs. Fifteen isolates of S. intermedius, four coagulase-negative staphylococci and a Micrococcus were inhibitory in vitro against at least one of the three indicator strains using direct and deferred inhibition tests. More dogs with antagonists were found in the pyoderma group and amongst laboratory beagles (p < 0.05) compared to healthy household pets. The frequency of all antagonists and of antagonistic S. intermedius from mucosae was higher in the pyoderma group compared to healthy household pets (p < 0.01 for both) and all healthy animals (p < 0.05 and p < 0.01, respectively). Increased competition at mucosae of infected dogs caused by higher populations of bacteria may have favoured the selection of antagonistic strains. Further studies, including tests for adherence and virulence are required to determine whether these isolates could be used as interfering strains against canine pyoderma. Résumé— L'antagonisme contre Staphylococcus intermedius a étéétudié parmi des bactéries isolées à partir de la peau et des muqueuses de 15 chiens présentant des pyodermites et de 42 chiens sains, effectif comprenant des chiens de particuliers, des beagles de laboratoire et des chiens guides. Parmi les souches isolées, 15 S. intermedius, 4 staphylocoques coagulase négatifs et un micrococcus se sont révélés inhibiteurs in vitro vis à vis d'au moins une des 3 souches indicatrices, à la fois dans des test d'inhibition directs et indirects. La plupart des chiens portcurs d'antagonistes appartenait au groupe pyodermite et au groupe beagles de laboratoire (p < 0,05) plutôt qu'au groupe chiens de particuliers sains. La fréquence de tous les antagonistes et du S. intermedius antagoniste isolés à partir des muqueuses était supérieure dans le groupe pyodermite par rapport au groupe chiens de particuliers sains (p < 0,01) pour les 2) et au groupe incluant la totalité des animaux sains (p <0,05 et p < 0,01 respectivement). Une compétition accrue au niveau des muqueuses de chiens infectés causée par un plus grand nombre de bactéries peut favoriser la sélection de souches antagonistes. D'autres études incluant des tests d'adhérence et de virulence sont nécessaires pour déterminer si ces souches isolées peuvent être utilisées comme antagonistes dans les infections cutanées. [Saijonmaa-Koulumies, L. E., LLOyD, D. H. Carriage of bacteria antagonistic towards Staphylococcus intermedius on canine skin and mucosal surfaces (Portage de bactéries antagonistes de Staphylococcus intermedius sur les surfaces muqueuses et cutanées chez le chien).     

Prevalence and risk factors for carriage of multi-drug resistant Staphylococci in healthy cats and dogs

We investigated the distribution of commensal staphylococcal species and determined the prevalence of multi-drug resistance in healthy cats and dogs. Risk factors associated with the carriage of multi-drug resistant strains were explored. Isolates from 256 dogs and 277 cats were identified at the species level using matrix-assisted laser desorption ionisation-time of flight mass spectrometry. The diversity of coagulase-negative Staphylococci (CNS) was high, with 22 species in dogs and 24 in cats. Multi-drug resistance was frequent (17%) and not always associated with the presence of the mecA gene. A stay in a veterinary clinic in the last year was associated with an increased risk of colonisation by multi-drug resistant Staphylococci (OR = 2.4, 95% CI: 1.1~5.2, p value LRT = 0.04). When identifying efficient control strategies against antibiotic resistance, the presence of mechanisms other than methicillin resistance and the possible role of CNS in the spread of resistance determinants should be considered.