Characterization of Coagulase-Negative Staphylococci and pheno-genotypic beta lactam resistance evaluation in samples from bovine Intramammary infection

Abstract

This study aimed to identify Coagulase-Negative Staphylococci (CoNS) species isolated from bovine mastitis, through phenotypic and PCR-RFLP (Restriction Fragment Length Polymorphism-Polimerase Chain Reaction) methods and to compare both techniques to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) technique. Among them, the PCR-RFLP method, using a partially conserved sequence of the groEL gene, is a promising alternative, because of its reproducibility and reliability. On the other hand, the proteomic technique MALDI-TOF MS provides an accurate and much faster diagnosis and has been increasingly employed in microbiological identification. The pheno-genotypic profiles of beta-lactam resistance were also investigated, this characterization is important, considering that the use of antimicrobials is a key element for mastitis control in dairy farms. The concordance of the phenotypic, PCR-RFLP and MALDI-TOF MS assays to identify CoNS species was 77,5% (31/40). S. chromogenes was the species most frequently isolated. Antibiotic resistance rate was relatively low, registering values of 25.5% to penicillin, 9.6% to oxacillin and 6.2% to cefoxitin. Resistance to imipenem, cephalotin and amoxicillin+clavulanate was not observed. The mecA gene and its variant were detected in 7.6% and 4,1% of the isolates respectively. The blaZ gene was found in 43.2% of the strains resistant to penicillin.Keywords: Staphylococcus spp., bacterial resistance, PCR-RFLP and MALDI-TOF MS 77,5% (31/40 RESUMO Este estudo teve como objetivo identificar isolados de Staphylococcus coagulase-negativa (SCN) isolados de mastite bovina, por meio de métodos fenotípicos e PCR-RFLP (reação em cadeia de polimerase -polimorfismo nos fragmentos de restrição), e compará-los com a técnica de tempo de voo de ionização/desorção por laser assistida por matriz de espectrofotometria de massa (MALDI-TOF MS). O método de PCR-RFLP, que utiliza uma parte conservada da sequência do gene groEL, é uma alternativa promissora, por ser reprodutível e confiável. Por outro lado, a técnica proteômica MALDI-TOF MS permite uma acurácia e um diagnóstico muito mais rápidos e tem sido cada vez mais empregada na identificação microbiológica. Os perfis fenogenotípicos de resistência aos beta-lactâmicos também foram investigados. Essa caracterização é importante, considerando-se que os antimicrobianos são os elementos-chave para o controle da mastite na produção leiteira. A concordância entre os testes fenotípicos, PCR-RFLP E MALDI-TOF MS na identificação foi de

Characterization of Staphylococcus spp. isolates and ß-lactam resistance in broiler chicken production

“…Despite the phenotypic resistance observed in S. gallinarum strains, none of resistance genes (mecA genes and blaZ) tested in this study was detected in this species. These findings corroborated with Melo et al (2018), that observed the same pattern evaluating β-lactam resistance in CoNS isolates from bovine intramammary infection. These results could support the hypothesis that these isolates have higher degrees of variability or suffer mutations that prevent its detection requiring further studies to better understanding.…”

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

“…The results presented in this study are in addition to others performed in the country that have identified cases of bovine mastitis due to MRSA and MRS . It should serve as a warning to animal health authorities regarding the improvement of programs for the control and rational use of antimicrobials in veterinary medicine (SOARES et al, 2012;MATOS, 2014;SILVA et al, 2014b;SANTOS et al, 2016;MELO et al, 2018). High use of antimicrobials or their indiscriminate use contributes to the selection and persistence of MRS strains; and consequently, their spread throughout the agricultural environment.…”

“…Contact between humans and animals positive for MRS and vice versa, may also favor pathogen transmission between species, and the environment may be a source of infection for both (JUHÁSZ-KASZANYITZKY et al, 2007). In Brazil, few studies have identified cases of mastitis caused by MRS (SOARES et al, 2012;MATOS, 2014;SANTOS et al, 2016;MELO et al, 2018). However, no study conducted in the country has evaluated and detected the presence of MRS isolates in cases of mastitis, workers, and the milking environment, and a possible genetic correlation between MRS isolates from various sources in the agricultural environment.…”

Antibiotic profile of Staphylococcus aureus and Coagulase negative Staphylococci species isolated from raw camel milk from Garissa County, Kenya

“…In animals, S. aureus and CoNS have been reported to cause mastitis, septicemia and arthritis in poultry (Simojoki et al, 2011;Sampimon et al, 2011). CoNS are increasingly being recognized as an important cause of mastitis in cattle in Kenya, Tanzania, Egypt, Tunisia, Czech Republic and other parts of the world including Europe, South America and the Middle East (Mbindyo et al, 2020;Soares et al, 2012;El-Razik et al, 2017;Srednik et al, 2017;Pyatov et al, 2017 andMelo et al, 2018).…”