Staphylococcal cassette chromosome mec elements from Staphylococcus intermedius group (SIG) isolates from dogs in a center for veterinary diagnostics in Brazil

Valcilaine Teixeira Barbosa,Rossana Teotônio De Farias Moreira,Diogo Brandão,Felipe Mendes Zorzi,Teresa De Lisieux Guedes Ferreira Lôbo,Luciano Aparecido Meireles Grilo,Regina Ruiz,Ticiano Gomes Do Nascimento,Rafael Aleixo Dos Santos Silva,Valter Alvino,Camila Braga Dornelas,Lara Mendes De Almeida,Rodrigo José Nunes Calumby,Elsa Masae Mamizuka,Suzanne Pinheiro Vieira

doi:10.1590/0103-8478cr20200936

Abstract

ABSTRACT: Methicillin resistance in the Staphylococcus intermedius group (SIG) has emerged in small animal practice. Methicillin-resistant SIG (MRSIG) members have been implicated as causes of infections in both companion animals and humans. Staphylococcal cassette chromosome mec (SCCmec) elements carry the mecA/C genes, which encode for the transpeptidase PBP2a (PBP2’) responsible for β-lactam antibiotic resistance in staphylococci. This study examined the SCCmec types of MRSIG isolates from different clinical specimens of dogs that exhibited methicillin MIC ≥ 0.5 μg/mL by an automated identification and susceptibility system in a Center for Veterinary Diagnostics in São Paulo, Brazil. Susceptibility to methicillin was determined by broth microdilution testing, and Oxoid® M.I.C.Evaluator® strips. PBP2a production was detected using a latex agglutination assay. SCCmec typing was performed according to the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) guidelines. SCCmec type II (2A), SCCmec type III (3A), composite SCC structures consisting of a class A mec gene complex in addition to multiple ccr gene complexes, and non-typable SCCmec elements were reported in these MRSIG isolates. SCCmec type variants differing from those so far acknowledged by IWG-SCC were found, indicating new rearrangements in the genetic context of mecA in these canine MRSIG isolates.

Highlights

Cassetes cromossômicos estafilocócicos mec de isolados do grupo Staphylococcus intermedius (GSI) de cães em um centro veterinário de diagnósticos no Brasil
Methicillin resistance in staphylococci occurs due to expression of the penicillin binding protein PBP2a (PBP2’), a transpeptidase which shows a slow rate of acylation by β-lactam antibiotics (FISHOVITZ et al, 2014)
PBP2a is encoded by the mecA or mecC genes that are carried by mobile staphylococcal cassette chromosome mec (SCCmec) elements (HIRAMATSU et al, 2013)

Summary

Introduction

Cassetes cromossômicos estafilocócicos mec de isolados do grupo Staphylococcus intermedius (GSI) de cães em um centro veterinário de diagnósticos no Brasil. SCCmec type assignment has been established by the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC), and it is based on a combination of the mec gene complex (mecA-C resistance genes, mecR1 and mecI regulatory genes, and insertion sequences), and the ccr gene complex (cassette chromosome recombinases ccr) (IGWSCC, 2009; HIRAMATSU et al, 2013).

Results

Conclusion