Biofilm formation and antimicrobial resistance genes of coagulase-negative staphylococci isolated from cows with mastitis in Argentina

Mastitis affects the health and welfare of dairy cows worldwide. Coagulase-negative staphylococci (CNS) are known to form biofilms and are increasingly recognized as a cause of persistent bovine intramammary infections. A total of 90 CNS isolated from cows with clinical and subclinical mastitis in Argentina from 2008 to 2014 were identified by PCR-RFLP using the gap gene. Standard microtiter plate assays were used to assess CNS biofilm formation, and Staphylococcus haemolyticus species formed the strongest biofilms. The presence of biofilm-associated genes icaA, bap and aap was detected in a few isolates, while embP, fbe, atlE and eno were present in the majority of isolates. Genes encoding resistance to β-lactams were detected among the isolates; blaZ, mecA and mecC were detected in 21, 4 and 1 isolate, respectively. Resistance to macrolides and lincosamides (n = 6) was attributable to ermB, ermC, mphC or mrsA or a combination of those genes. In this study, we identified CNS species involved in mastitis and provide information about pathogenicity and antimicrobial resistance, which is essential to design efficient strategies to control mastitis caused by CNS.Fil: Srednik, Mariela Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Área de Microbiología Veterinaria; ArgentinaFil: Tremblay, Yannick D.N.. University of Montreal; CanadáFil: Labrie, Josée. University of Montreal; CanadáFil: Archambault, Marie. University of Montreal; Canadá. Regroupement de Recherche Pour un lait de Qualite Optimale; CanadáFil: Jacques, Mario. University of Montreal; Canadá. Regroupement de Recherche Pour un lait de Qualite Optimale; Canadá. Canadian Bovine Mastitis and Milk Quality Research Network; CanadáFil: Fernandez Cirelli, Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Gentilini, Elida Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Área de Microbiología Veterinaria; Argentin