Open AccessGenotyping and antimicrobial resistance of Streptococcus uberis isolated from bovine clinical mastitis
Author(s) -
Tiago Tomazi,
Gustavo Freu,
Bruna Farias Alves,
Antônio Francisco de Souza Filho,
Marcos Bryan Heinemann,
Marcos Veiga dos Santos
Publication year - 2019
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0223719
Subject(s) - streptococcus uberis , biology , microbiology and biotechnology , genotyping , rapd , mastitis , penicillin , genotype , antimicrobial , ceftiofur , antibiotic resistance , ampicillin , veterinary medicine , antibiotics , streptococcus , medicine , genetics , genetic diversity , bacteria , population , environmental health , gene
A genotypic characterization of Streptococcus uberis isolated from clinical mastitis (CM) in dairy cows, and the association of Strep . uberis genotypes and antimicrobial susceptibility (AMS) was performed. A total of 89 isolates identified as Strep . uberis from 86 dairy cows with CM in 17 dairy herds of Southeastern Brazil were genotyped using random amplified polymorphic DNA (RAPD) analysis. After genotyping, two clusters (I and II) were created according to RAPD types. A commercial broth microdilution test was used to determine the susceptibility of Strep . uberis isolates to 8 antimicrobials (ampicillin, ceftiofur, cephalothin, erythromycin, penicillin, penicillin+novobiocin, pirlimycin and tetracycline). For each antimicrobial, we determined the minimal inhibitory concentrations that inhibit 50% (MIC 50 ) and 90% (MIC 90 ) of Strep . uberis strains. Differences in AMS among genotypic clusters were evaluated using mixed regression models. Overall, a great polymorphism (56 RAPD-types) was found among Strep . uberis isolates, although a higher genetic similarity (based on the PCR bands features) was observed within herds after genotypic clustering. No differences in AMS were observed among clusters. Strep . uberis isolated from bovine CM were resistant to most antimicrobials, with the exception of cephalothin and penicillin+novobiocin.