Caracterização de Staphylococcus spp. isolados de leite caprino no Estado da Paraíba.

Abstract

The main disease that affects the goat dairy herd is intramammary infections, which usually have coagulase negative (SCN) and positive (SCP) Staphylococcus etiology. In this north, the present study aimed at the genotypic and phenotypic characterization of Staphylococcus isolated from subclinical goat mastitis as well as to characterize the virulence factors associated with these bacteria. 400 goat milk samples were collected from 25 farms distributed in five municipalities in Paraíba that have a dairy goat herd, resulting in 105 isolations characteristic of Staphylococcus spp., The species were identified by Malditof. The genotyping of the isolates was performed using REPPCR, using the primer RW3A, the images were processed by the software BioNumerics ©, the degree of similarity was established using the Jaccard coefficient (5%). Individual PCRs were carried out aiming to identify sea, seb, sec, sed, see, sec, seh and sei enterotoxin genes and blaZ and mecA resistance genes, hemolytic samples were tested for IcaD. The reactions had a final volume of 50μL, PCR SuperMix (Invitrogen, Brazil) was used with 0.4 mM of each primer. The determination of phenotypic resistance was performed using the disk diffusion technique. The following discs were used: Cefoxitin 30μg, Oxacillin 1μg, Gentamicin 10μg, Erythromycin 15μg, Tetracycline 30μg, Ciprofloxacin 5μg, Sulfa / Trimetropim 25μg, Clindamycin 2μg, Penicillin 10U, Clorafenicol 30μg. Fisher's exact test (p >0,05) was performed to buy species and resistance. A total of 15 species of Staphylococcus were identified in the five municipalities evaluated. The main species causing subclinical mastitis were S. epidermidis (36%), S. caprae (24%), S. lugdunensis (13%), S. simulans (7%) and S. xylosus (4%). The municipality that presented the greatest diversity of species was Prata. REPPCR identified 28 profiles with 100% similarity, it was observed that bacterial species genotypically clones (100% similarity) are responsible for subclinical mastitis in different cities. The presence of enterotoxin genes was identified in eight Staphylococcus (7.6%), of these three presented sec and five seh, three samples presented the sec and seh gene simultaneously. High resistance rates have been identified for Penicillin (40%), Sufa / Trimetropim (33%) and Tetracycline (25.5%). Three strains of SCN showed phenotypic resistance to oxacillin characterizing MRSCN and a strain of S. aureus (MRSA). All samples were sensitive to Gentamicin. In the investigation of the genotypic resistance profile, positive isolates for the blaZ (26.6%) and mecA (1.1%) genes were revealed. Hemolytic isolates tested for icaD (50%), biofilm production capacity was observed. Considering the characterization of the main bacterial agents that cause mastitis and its virulence and resistance factors, they guide the role of the goat food chain as reservoirs of pathogens that generate public health risks, the high rates of resistance and identification of biofilm producing strains indicate flaws in therapeutic practices.