Biofilm production and beta-lactamic resistance in Brazilian Staphylococcus aureus isolates from bovine mastitis
Marques, Viviane Figueira, Motta, Cássia Couto da, Soares, Bianca da Silva, Melo, Dayanne Araújo de, Coelho, Shana de Mattos de Oliveira, Coelho, Irene da Silva, Barbosa, Helene Santos, Souza, Miliane Moreira Soares de
Braz. J. Microbiol.
DATA DE PUBLICAÇÃO
Abstract Staphylococcus spp. play an important role in the etiology of bovine mastitis. Staphylococcus aureus is considered the most relevant species due to the production of virulence factors such as slime, which is required for biofilm formation. This study aimed to evaluate biofilm production and its possible relation to beta-lactamic resistance in 20 S. aureus isolates from bovine mastitic milk. The isolates were characterized by pheno-genotypic and MALDI TOF-MS assays and tested for genes such as icaA, icaD, bap, agr RNAIII, agr I, agr II, agr III, and agr IV, which are related to slime production and its regulation. Biofilm production in microplates was evaluated considering the intervals determined along the bacterial growth curve. In addition, to determine the most suitable time interval for biofilm analysis, scanning electron microscopy was performed. Furthermore, genes such as mecA and blaZ that are related to beta-lactamic resistance and oxacillin susceptibility were tested. All the studied isolates were biofilm producers and mostly presented icaA and icaD. The Agr type II genes were significantly prevalent. According to the SEM, gradual changes in the bacterial arrangement were observed during biofilm formation along the growth curve phases, and the peak was reached at the stationary phase. In this study, the penicillin resistance was related to the production of beta-lactamase, and the high minimal bactericidal concentration for cefoxitin was possibly associated with biofilm protection. Therefore, further studies are warranted to better understand biofilm formation, possibly contributing to our knowledge about bacterial resistance in vivo.
- Methods for Identification of Staphylococcus aureus Isolates in Cases of Bovine Mastitis
- Comparison of methods for the detection of biofilm formation by Staphylococcus aureus isolated from bovine subclinical mastitis
- Biofilm production by Staphylococcus spp. isolated from bovine mastitis in dairy herds in state of Acre, Brazil and its implications
- Isolation of Staphylococcus aureus L forms from experimentally induced bovine mastitis.
- Enterotoxigenicity of Staphylococcus aureus Cultures Isolated from Acute Cases of Bovine Mastitis