MecA positive Staphylococcus spp. in bovine mastitis, milkers, milking environment, and the circulation of different MRSA clones at dairy cows farms in the Northeast region of Brazil

José Givanildo Da Silva,Breno Bezerra Aragão,Rinaldo Aparecido Mota,Anderson Carlos Camargo,Renata Pimentel Bandeira De Melo,Luís Augusto Nero,Junior Mário Baltazar De Oliveira,Maria José De Sena

doi:10.1590/0103-8478cr20210008

José Givanildo Da Silva, Breno Bezerra Aragão + Show 6 more

Open Access

https://doi.org/10.1590/0103-8478cr20210008

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Abstract

ABSTRACT: This study detected the presence and distribution of mecA in Staphylococcus spp. in the dairy production environment at farm level in Brazil. We analyzed 335 samples of mastitis cow milk, 15 samples of nostrils and hand swabs from milkers, 14 teat cup swabs, and 9 milking buckets swabs. Initially, the samples were subjected to microbiological analysis to detect Staphylococcus spp. and then S. aureus and mecA positive isolates were identified by PCR. All S. aureus isolates carrying the mecA genes were subjected to DNA macro-restriction analysis by Pulsed-Field Gel Electrophoresis (PFGE). The mecA gene was detected in 6/335 (1.78%) of mastitis cow milk, 5/15 (33.3%), and 5/15 (33.3%) of nostrils and hand swab, and 4/14 (28.5%) of the teat cup isolates. MRSA genotyping was performed by PFGE, a total of seven pulsotypes were grouped in two clusters. This study identified the occurrence and spread of MRSA at dairy environment of farms, and also the existence of distinct genetic profiles between isolates.

Highlights

Mastitis is a plurietiological and multifactorial disease that is often caused by bacteria of the genus Staphylococcus
The genetic profiles of 10 Methicillin Resistant Staphylococcus aureus (MRSA) isolates identified in the present study were revealed by Pulsed-Field Gel Electrophoresis (PFGE) after macrorestriction performed with the enzyme SmaI (Figure 1)
Isolates 163 RAT, 164 RRT and 30 RRT shared the same genetic profile; they originated from farms far away, indicating that genetically similar MRSA strains are widespread in different regions of Pernambuco state, Brazil

Summary

Introduction

These bacteria is opportunistic pathogen associated with a wide variety of infections in humans and animals (WILLE et al, 2014; WONG, 2002). Another concern related to mastitis caused by Staphylococcus spp. is the emergence of antimicrobial resistant strains, such as MethicillinResistant Staphylococcus (MRS) (LIM et al, 2013). Twelve types of SCCmec that harbor mecA and/or mecC are known; both these genes encode an altered penicillin binding proteins (PBP) called PBP2a/PBP2’ and a peptideoglycan transpeptidase that result in a decreased affinity for this class of antimicrobials (KIM et al, 2012; BAIG et al, 2018; LEE et al, 2018) This encoding allows Staphylococcus spp. to maintain its biosynthesis even at concentrations considered to be inhibitory to these antimicrobials (LIVERMORE, 2000; PATERSON et al, 2014)

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