RESUMO
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 ß-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.
Assuntos
Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla/genética , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/fisiologia , Animais , Argentina , Bovinos , Coagulase/genética , Coagulase/metabolismo , Feminino , Genes Bacterianos , Testes de Sensibilidade Microbiana , Polimorfismo de Fragmento de Restrição , Reação em Cadeia da Polimerase em Tempo Real , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Staphylococcus/isolamento & purificaçãoRESUMO
Actinobacillus pleuropneumoniae is the aetiological agent of porcine pleuropneumonia and is normally transmitted by aerosols and direct contact between animals. A. pleuropneumoniae has traditionally been considered an obligate pathogen of pigs and its presence in the environment has yet to be investigated. Here, the presence of A. pleuropneumoniae was detected in drinking water of pig farms in Mexico using a PCR specific for the RTX toxin gene, apxIV. The presence of A. pleuropneumoniae in farm drinking water was confirmed by indirect immunofluorescence using an A. pleuropneumoniae-specific polyclonal antibody and by fluorescent in situ hybridization. Viable bacteria from the farm drinking water were detected using the Live/Dead BacLight stain. Additionally, viable A. pleuropneumoniae was selected and isolated using the cAMP test and the identity of the isolated bacteria were confirmed by Gram staining, a specific polyclonal antibody and an A. pleuropneumoniae-specific PCR. Furthermore, biofilms were observed by scanning electron microscopy in A. pleuropneumoniae-positive samples. In conclusion, our data suggest that viable A. pleuropneumoniae is present in the drinking water of swine farms and may use biofilm as a strategy to survive in the environment.