Dados do Trabalho

Título

Emergence of livestock-associated Mammaliicoccus sciuri ST71 co-harbouring mecA and mecC genes in Brazil

Objetivos(s)

The global dissemination of antibiotic-resistant bacteria represents a red-alert public health threat, in which methicillin resistance has been in the spotlight. Thus, we report the first double mecA/mecC homologue-positive NASM from the American continent, also representing the first report of mecC-positive NASM in Brazil.

Relato do Caso

During a local surveillance study conducted to assess the occurrence of clinically important antimicrobial-resistant bacteria in ewes in Northeast Brazil, the antimicrobial resistance (AMR) phenotypical screening using the Vitek 2® kit (BioMériux, USA) alerted us to the presence of methicillin resistance in aseptically collected milk samples. Thus, from one ewe, we aseptically collected milk samples and teat skin swabs from both udder ewes’ halves for bacteriological analysis. Antimicrobial disks were also used to test for resistance to cefoxitin and oxacillin. The phenotypic results of the AMR were interpreted according to the Clinical and Laboratory Standards Institute recommendations. Whole genome sequencing was performed on two M. sciuri isolates (originated from milk and teat skin samples from the same udder half) by using MiSeq Reagent Kit v2 (Illumina, Inc.) in a MiSeq V3 machine (Illumina Inc.) at Neoprospecta facilities.
Two clonally related methicillin-resistant M. sciuri strains co-carrying mecA and mecC genes were isolated from the teat skin and intramammary infection of one lactating ewe's udder. Both M. sciuri strains belonged to the sequence type (ST) 71. Besides mecA and mecC genes, the M. sciuri strains carried broad resistomes for clinically important antimicrobial agents, including β-lactams, tetracyclines, lincosamide, streptogramin, streptomycin, and aminoglycosides. Virulome analysis showed the presence of the clumping factor B (clfB), ATP-dependent protease ClpP (ClpP) and serine-aspartate repeat proteins (sdrC and sdrE) virulence-associated genes. Phylogenomic analysis revealed that these M. sciuri strains are part of a globally disseminated branch, associated with farm and companion animals and even with food.

Conclusão

Our findings suggest that M. sciuri is likely to emerge as a pathogen of global interest, carrying a broad repertoire of antimicrobial resistance genes with a remarkable co-presence of mecA and mecC genes. Finally, we strongly encourage to monitor M. sciuri under the One Health umbrella since this bacterial species is spreading at the human-animal-environment interface.

Agradecimentos

CNPq Project no. 423191/2018-7