Impairments of mecA gene detection in bovine Staphylococcus spp.

• Main Authors: Dayanne Araújo de Melo, Irene da Silva Coelho, Cássia Couto da Motta, Anna Carolina Coelho Marín Rojas, Felipe Carlos Dubenczuk, Shana de Mattos de Oliveira Coelho, Miliane Moreira Soares de Souza
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Microbiologia 2014-09-01
• Series: Brazilian Journal of Microbiology
• Subjects: antimicrobial resistance; bovine mastitis; Staphylococccus; mecA gene
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000300041&lng=en&tlng=en

Staphylococcus aureus antimicrobial resistance, especially to beta-lactams, favors treatment failures and its persistence in herd environment. This work aimed to develop a more specific primer for mecA gene detection based on the comparison of the conserved regions from distinct host origins and also investigated the presence of homologue mecA LGA251 in bovine strains. A total of 43 Staphylococcus spp. were included in this study, comprising 38 bovine S. aureus, two human and three equine coagulase-negative staphylococci (CNS). Phenotypical methicillin-resistance detection was performed through oxacillin agar-screening and cefoxitin disk-diffusion test. None isolate tested positive for mecA LGA251 gene. For mecA gene PCR, new primers were designed based on the sequences of human S. aureus (HE681097) and bovine S. sciuri (AY820253) mecA. The new primers based on the S. aureus mecA sequence amplified fragments of human and equine CNS and the ones based on S. sciuri mecA sequence only yielded fragments for S. aureus bovine strains. Multiples alignments of mecA gene sequences from bovine, human and equine revealed punctual but significant differences in bovine strains that can lead to the mecA gene detection impairment. The observed divergences of mecA gene sequences are not a matter of animal or human origin, it is a specificity of bovine samples.