Title:	Virulence, agr groups, antimicrobial resistance and epidemiology of Staphylococcus aureus isolated from bovine subclinical mastitis.
Authors:	ZORZI, F. M. ZAFALON, L. F. SANTOS, F. B. NASCIMENTO, T. G. BASÍLIO JUNIOR, I. D. MAMIZUKA, E. M. ALMEIDA, L. M.
Affiliation:	FELIPE MENDES ZORZI, USP; LUIZ FRANCISCO ZAFALON, CPPSE; FRANKLIN BISPO SANTOS, Universidade Federal de Alagoas; TICIANO GOMES NASCIMENTO, Universidade Federal de Alagoas; IRINALDO DINIZ BASÍLIO-JÚNIOR, Universidade Federal de Alagoas; ELSA MASAE MAMIZUKA, USP; LARA MENDES ALMEIDA, Universidade Federal de Alagoas; Universidade de São Paulo.
Date Issued:	2021
Citation:	Brazilian Journal of Veterinary Research and Animal Science, v.58, e186701, 2021.
Description:	Fifty-two Staphylococcus aureus recovered from papillary ostium and milk samples collected from cows with subclinical mastitis and milking environments in three small dairy herds located in southeastern Brazil were subjected to PCR identification based on the thermonuclease (nuc) gene. All the strains were submitted to in vitro antimicrobial susceptibility testing, and we investigated the sequence types (STs), agr groups (I-IV), virulence genes encoding for Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs), biofilm-associated proteins, bi-component toxins, pyrogenic toxin superantigens, and enterotoxins. Screening for oxacillin resistance (2-6 μg/ml oxacillin), beta-lactamase activity assays, and PCR for the mecA/mecC genes detected 26 methicillin-susceptible S. aureus (MSSA) and 26 mec-independent oxacillin-nonsusceptible S. aureus (MIONSA). While MSSA isolates were found to be susceptible to all antimicrobial agents tested, or only resistant to penicillin and ampicillin, MIONSA isolates were multidrug-resistant. ST126-agr group II MSSA isolates were prevalent in milk (n=14) and carried a broad set of virulence genes (clfA, clfB, eno, fnbA, fiB, icaA, icaD, lukED, hla, and hlb), as well as the ST126-agrgroup II MIONSA isolated from milking liners (n=1), which also carried the etagene. ST1-agr group III MIONSA isolates (n=4) were found in papillary ostium and milk, but most MIONSA isolates (n=21), which were identified in both papillary ostium and milking liners, were agr-negative and assigned to ST126. The agr -negative and agr group III lineages showed a low potential for virulence. Studies on the characterization of bovine-associated MSSA/MIONSA are essential to reduce S. aureus mastitis to prevent economic losses in dairy production and also to monitor the zoonotic potential of these pathogens associated with invasive infections and treatment failures in healthcare.
NAL Thesaurus:	Bovine mastitis
Keywords:	MSSA MIONSA Accessory gene regulator (agr)
ISSN:	1678-4456
DOI:	https://doi.org/10.11606/issn.1678-4456.bjvras.2021.186701
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CPPSE)