Detection of Enterotoxigenic Potential and Determination of Clonal Profile in Staphylococcus aureus and Coagulase-Negative Staphylococci Isolated from Bovine Subclinical Mastitis in Different Brazilian States.

Priscila Mello,Lisiane De Almeida Martins,Maria Ribeiro De Souza Da Cunha,Luiza Pinheiro,Danilo Moraes Riboli,Maria Vasconcelos Paiva Brito

doi:10.3390/toxins8040104

Abstract

Epidemiological studies have identified Staphylococcus aureus as the most common agent involved in food poisoning. However, current research highlights the importance of toxigenic coagulase-negative staphylococci (CoNS) isolated from food. The aim of this study was to characterize Staphylococcus spp. isolated from cows with bovine subclinical mastitis regarding the presence of genes responsible for the production of staphylococcal enterotoxins and of the tst-1 gene encoding toxic shock syndrome toxin 1, and to determine the clonal profile of the isolates carrying any of the genes studied. A total of 181 strains isolated in different Brazilian states, including the South, Southeast, and Northeast regions, were analyzed. The sea gene was the most frequent, which was detected in 18.2% of the isolates, followed by seb in 7.7%, sec in 14.9%, sed in 0.5%, see in 8.2%, seg in 1.6%, seh in 25.4%, sei in 6.6%, and ser in 1.6%. The sej, ses, set, and tst-1 genes were not detected in any of the isolates. The typing of the isolates by pulsed-field gel electrophoresis revealed important S. aureus and S. epidermidis clusters in different areas and the presence of enterotoxin genes in lineages isolated from animals that belong to herds located geographically close to each other.

Highlights

IntroductionSeveral microorganisms are involved in mammary gland infections in production animals
Several microorganisms are involved in mammary gland infections in production animals.National and international epidemiological studies have demonstrated the presence of the genusStaphylococcus in approximately 50% of bovine mastitis cases, highlighting the role of this group as the main causative agent of this infection [1]
In a study conducted in Brazil, Rall et al [2] found a prevalence of these microorganisms of 27.4%, while 28.6% of the isolates were S. aureus in a study conducted in Turkey [3]

Summary

Introduction

Several microorganisms are involved in mammary gland infections in production animals. Staphylococcus in approximately 50% of bovine mastitis cases, highlighting the role of this group as the main causative agent of this infection [1]. Staphylococcus aureus is the most common agent involved in subclinical mastitis, coagulase-negative staphylococci (CoNS) have gained importance as causative agents of intramammary infections. Studies [4,5] have emphasized the importance of toxigenic CoNS isolated from food. S. aureus is the most common agent involved in food poisoning, there is current concern in the scientific community regarding CoNS, which have been recognized as opportunistic pathogens in human and animal infections, allied to risks of toxigenic lineages in cases of food poisoning in humans [5]

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Conclusion