Bacterial identification, somatic cell count, antimicrobial profile and toxigenic Staphylococcus strains search from mastitic cow milk samples on small farms properties

Abstract

Bovine mastitis has a negative impact on milk production and can pose risks to public health. The present study aimed to evaluate the quality of bovine milk from small farms in the Botucatu/SP region. Somatic cell counts (SCC), identification of pathogens involved in mastitis, and sensitivity antimicrobial profile of staphylococci isolated were performed. The presence of enterotoxin encoding genes in isolates of staphylococci obtained from milk was investigated. Milk samples from individual mammary quarters of cows were submitted to the California mastitis test (CMT) and SCC. Of the 239 dairy cows from 21 dairy herds evaluated (mean = 11.4 animals/property), two cows (0.8%) presented clinical mastitis and 86 (35.9%) subclinical mastitis. Bacterial culture was performed in 177 quarter milk samples. Staphylococci were identified in 55 (31.1%), corynebacteria in 45 (25.4%), streptococci in 25 (14.1%) and coliforms in four (2.3%) milk samples. Average SCC from culture-positive samples was 1598x103 cells/mL, in case of staphylococci was 1362x103 cells/ml, streptococci was 2857x103 cells/mL, corynebacteria was 976x103 cells/mL and in the cases of coliforms 1161x103 cells/mL were obtained. Staphylococci showed a high sensitivity (>95%) to cephalothin, cotrimoxazole, enrofloxacin, and gentamicin, with a 41.2% resistance to penicillin and 11.8% to oxacillin. Both coagulase positive (CPS) and negative staphylococci (CNS) carried genes encoding enterotoxins in 21.6% of the first group and 41.9% in the second. The sea gene was the most detected 45.8% (n=24) between them, followed by seb with 29.2% and sec with 25.0%. The sed gene was not identified. We highlight the potential risk to public health in the possibility of strains of Staphylococcus spp. enterotoxin-producing genes that can cause staphylococcal food poisoning.

Species identification and antimicrobial susceptibility profile of bacteria associated with cow mastitis in southern Brazil

“…In addition, CPS were also detected, including seven S. aureus that is considered the main etiologic agent of cow mastitis worldwide (Freitas et al 2018). Curiously, S. aureus frequency observed here was lower than in other Brazilian studies with this disease in cow herds (Krewer et al 2014, Valmorbidaet al 2017, Freitas et al 2018, Lavor et al 2019. This epidemiological feature is probably associated with the differences in the cows microbiotas from dairy farms located in different geographic regions.…”

“…Staphylococcus spp. was also the most commonly bacterial genus isolated from bovine mastitis in previous studies carried out in Brazil (Oliveira et al 2011, Haubert et al 2017, Valmorbida et al 2017, Lavor et al 2019) and even in other countries (Sztachańska et al 2016, Vakkamäki et al 2017, Kim et al 2019). On contrast, 56 milk samples dit not present bacterial growth.…”

Elaboração De Sorvete a Base De Leite De Cabra, Adoçado Com Açúcar E/Ou Mel De Abelhas

“…A produção científica sobre qualidade do leite em Minas Gerais, no biênio 2019- A presença de S. aureus e S. agalactiae (COSTA, G., et al, 2019;COSTA, H., et al, 2019;LAVOR et al, 2019;MESQUITA et al, 2019a;MESQUITA et al, 2019b), além da aparente ineficácia na pasteurização por parte da indústria laticinista mineira (SANTOS E BEVILACQUA, 2019) criam uma preocupação com patógenos presentes nos produtos lácteos e uma necessidade de adoção de uma sistemática mais eficiente de identificação e controle dos microrganismos.…”

“…A qualidade do leite também foi avaliada em estudo realizado em pequenas propriedades na região de Botucatu, São Paulo, por Lavor et al (2019), que compararam a CCS e identificaram os agentes envolvidos com a mastite. Foi constatado que Staphylococcus aureus foi o principal agente encontrado e que o S. agalactiae representou o mais significativo microrganismo responsável por aumentar a CCS nas vacas, corroborado por Radostits et al (2000), que afirma que esse patógeno leva a um aumento na CCS dos animais e que, consequentemente, é o provável responsável por aumentar o referido parâmetro no leite de tanque de resfriamento.…”

Detection of β-lactamase, blaZ and mecA in penicillin-resistant Staphylococcus aureus isolated from bovine mastitis in Garanhuns, Brazil

“…In worldwide, mastitis by that bacteria is one of the most important diseases, particularly in dairy herds (ABEBE et al, 2016;FELIPE et al, 2017;FREITAS et al, 2018;LAVOR et al, 2019).…”