ABSTRACT
Foram estudadas 135 vacas mestiças, provenientes de 10 rebanhos leiteiros no estado do Acre. O objetivo foi identificar espécies de Staphylococcus isoladas dos quartos mamários de vacas com mastite e, posteriormente, avaliar a capacidade de produção de biofilme pela espécie Staphylococcus chromogenes. A caracterização dos isolados presentes nas amostras encontradas, correspondentes a Staphylococcus sp., foi realizada utilizando-se a técnica do MALDI TOF MS (Matrix Associated Laser Desorption-Ionization - Time of Flight - Mass Spectrometry). Foram identificados: S. chromogenes (36), Staphylococcus saprophyticus (5), S. chromogenes ou Staphylococcus hycus (5), Staphylococcus haemolyticus (4), Staphylococcus epidermidis (3), Staphylococcus hycus (3), Staphylococcus aureus (1), Staphylococcus auriculares (1), Staphylococcus kloosii (1) e Staphylococcus xylosus (1). A espécie S. chromogenes correspondeu a 60% dos isolados do gênero (17 isolados coagularam o plasma de coelho no teste da coagulase em tubo), sendo 83,3% dos isolados (30/36) produtores de biofilme, não estando esse fator de virulência associado ao fenótipo de coagulação do plasma. A identificação desses microrganismos é importante para a elucidação da etiologia da mastite bovina. O alto percentual de S. chromogenes, produtores de biofilme, isolados de vacas com mastite é um achado relevante e pode revelar uma mudança de perfil na colonização de agentes etiológicos causadores dessa enfermidade.(AU)
A total of 135 crossbred cows was studied, from ten dairy herds on the state of Acre. The purpose was to identify species of Staphylococcus isolated from the mammary quarters of cows with mastitis. Additionally, the capacity of biofilm production by the species Staphylococcus chromogenes was evaluated. The sample characterization of the isolates was performed using the MALDI TOF MS (Matrix Associated Laser Desorption-Ionization - Time of Flight - Mass Spectrometry). The following species were identified by MALDI TOFF MS: S. chromogenes (36), Staphylococcus saprophyticus (5), S. chromogenes or Staphylococcus hycus (5), Staphylococcus haemolyticus (4), Staphylococcus epidermidis (3), Staphylococcus hycus (3), Staphylococcus aureus (1), Staphylococcus auriculares (1), Staphylococcus kloosii (1) and Staphylococcus xylosus (1). S. chromogenes corresponded to 60% of the Staphylococcus isolates (17 isolates positive on tube coagulase test). From those, 83.33% (30/36) of them were biofilm producers. This virulence factor had no association with the plasma coagulation phenotype. The identification of these microorganisms is important for the elucidation of the bovine mastitis etiology. The high percentage of S. chromogenes, biofilm producers, isolated from cows with mastitis is an important finding. This may reveal a profile change on the colonization of etiologic agents that cause this disease.(AU)
Subject(s)
Animals , Cattle , Staphylococcus/isolation & purification , Biofilms/classification , Milk/microbiology , Mastitis, Bovine/microbiology , Cattle/microbiologyABSTRACT
Phenotypic characteristics, antimicrobial susceptibility, and genetic relationships were analyzed in 107 Staphylococcus aureus isolates recovered from cows with subclinical mastitis in Southeastern Brazil. Thirteen different biochemical patterns were detected among isolates. A predominant pattern represented by about 54% of the isolates was distributed among several herds. Isolates of distinct phenotypic profiles were also detected within a herd. Susceptibility to ampicillin, cefotaxime, cephalotin, chloramphenicol, erythromycin, gentamycin, kanamycin, nitrofurantoin, norfloxacin, ofloxacin, oxacillin, penicillin, rifampin, sulfamethoxazole-trimethoprim, tetracycline, trimethoprim, and vancomycin, determined by the disk diffusion method, was observed in 44.9% of isolates. On the other hand, 55.1, 7.4, and 2.8% of the strains were resistant to ampicillin/penicillin, tetracycline, and erythromycin, respectively. Genetic diversity was analyzed by pulsed-field gel electrophoresis using SmaI as the restriction enzyme. All isolates could be typed by pulsed-field gel electrophoresis, which identified 16 types and 24 subtypes. Type A and its subtypes comprised 54.2% of all isolates and were recovered from 6 of the 9 herds analyzed. Other types and subtypes were also found in multiple herds. Although multiple types and subtypes were found within a specific herd, a predominant type was frequently observed.
