Characterization of virulence and antibiotic profile and agr typing of Staphylococcus aureus from milk of subclinical mastitis bovine in State of Rio de Janeiro

Abstract

This study aims to detect the main virulence and antimicrobial resistance genes in Stapylococcus aureus from bovine mastitic milk as well as classifying them according to agr typing. A total of 55 strains from six dairy unities in the state of Rio de Janeiro were selected, of these 27.3% presented fbnA and 78,2% for fbnB genes, respectively. None of the strains tested were positive for cap5 gene, 3.6% were positive for cap8 gene. Additionally, 94.5% of strains had hlA gene and 89.1% had hlB gene while 67.3% of the strains had icaA gene and 87.3% had icaD gene. From these results it was possible to establish 12 different virulence profiles. Prevalence of agrII type was detected in 81.8% of the isolates. Concerning antimicrobial resistance evaluation, the studied strains were susceptible to all antibiotics tested except penicillin, 83.6% being resistant strains. None of the strains had mecA gene, however, 40% of the strains had blaZ gene. Associating virulence and resistance data made it possible to obtain 23 different profiles. This great diversity of strains shows wide array of bacterial strategies and the challenge of mastitis prevention in cattle. Despite antimicrobial susceptibility, these strains presented certain genes that allow its persistence in the herd.

Capsular Typing of Staphylococcus aureus Isolated from Raw Milk Samples using Duplex Polymerase Chain Reaction

“…Salasia et al, (2004) observed that majority of the strains (12 out of 19) isolated in Hesse, Germany harboured the gene cap8 while Ikawaty et al, (2010) detected cap8 in 73 isolates and cap5 in three isolates from Netherlands. Some workers didn't record any of the isolates harbouringcap8 gene (Proietti et al, 2010) or carrying cap5 gene (Soares et al, 2017). Nontypable strains as observed in this study were also reported by Upadhyay et al, (2010); Yadav et al, (2015) from the same laboratory and locations.…”

Molecular Detection of Some Virulence Genes of Staphylococcus aureus Isolates Associated with Bovine Mastitis in Arid and Semi-Arid Regions of India

“…As compared to present study a higher percentage of S. aureus isolates were detected with fnbB gene by other workers from bovine mastitis i.e. 80% by Wang et al, (2016) 76.3% by Felipe et al, (2017; 78.2% by Soares et al, (2017) and 85% by Zhang et al, (2018) while none of the investigated S. aureus strains harbouring fnbB gene was reported by Yang et al, (2012). These variations have been suggested to depend either on the specific geographic region or, alternatively, on methodological differences.…”

“…The prevalence of fnbA gene has been reported as high as 100% in S. aureus isolates from intramammary infections by workers from different study areas (Yang et al, 2012;Felipe et al, 2017;Baloch et al, 2018) to as low as 27.3% by Soares et al, (2017). Further, fnbA gene was not detected in any strain from bovine subclinical mastitis by Memon et al, (2013) andHe et al, (2014).…”

Characterization of Staphylococcus aureus isolates from mastitic milk, udder surfaces and milkers' hands from arid and semi arid regions of India for capsular (cap5K and cap8K) and collagen adhesin (cna) genes

“…(2010) detected cap8 in 73 isolates and cap5 in three isolates from Netherlands. Some workers did not record any of the isolates harbouring cap8 gene (Proietti et al 2010) or carrying cap5 gene (Soares et al 2017).…”