Comparison of the population structure of Streptococcus uberis mastitis isolates from Austrian small-scale dairy farms and a Slovakian large-scale farm

Abstract

Streptococcus uberis, a major mastitis pathogen associated with intramammary infections (IMI), can be found ubiquitously in the cow's environment. Although Strep. uberis is reported to be susceptible to most antimicrobials, in practice poor responses to treatment and recurrent mastitis are observed. This can be explained by reinfection or by persistence of strains. We hypothesized that among a heterogeneous group of Strep. uberis mastitis isolates, some predominant host-adapted clones might be recurrently isolated from IMI. Therefore, the aim of this pilot study was to determine the Strep. uberis genotype variety found among small-scale dairy herds (127 Austrian dairy farms) and compare this with a large-scale herd (a Slovakian dairy farm). We determined the occurrence and strain diversity of Strep. uberis (n = 309) isolates using molecular analysis. Streptococcus uberis isolates from aseptically collected quarter milk samples were genotypically characterized using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. The Strep. uberis strain set covered isolates from 4 Austrian federal areas [

Genotyping and Antimicrobial Susceptibility Profiling of Streptococcus uberis Isolated from a Clinical Bovine Mastitis Outbreak in a Dairy Farm

“…The coexistence of these two modes of transmission might be the reason for the high number of Strep. uberis CM cases within the studied herd, as recently suggested [9]. Control measures focused on the improvement of environmental hygiene [37] may not be sufficient and different management decisions can be recommended on each farm [8,9].…”

“…Resistance to β-lactam antibiotics was present, with 11 (15.5%) isolates resistant to penicillin, three (4.2%) to oxacillin, one to first-generation (cefazolin) and fourth-generation (cefquinome) cephalosporins, and two isolates resistant to third-generation (cefoperazone and ceftiofur). 1 Susceptible, 2 Intermediate, 3 Resistant, 4 Amoxicillin/clavulanic acid, 5 Ampicillin, 6 Cefazolin, 7 Cefoperazone, 8 Cefquinome, 9 Ceftiofur, 10 Enrofloxacin, 11 Erythromycin, 12 Florfenicol, 13 Lincomycin, 14 Oxacillin, 15 Penicillin, 16 Tetracycline, 17 Trimethoprim/sulfamethoxazole.…”

“…The cluster I isolates showed significantly higher MIC values than those of cluster II for amoxicillin plus clavulanate (p value = 0.034) and for ceftiofur (p value = 0.01) (Table S1). 1 Amoxicillin/clavulanic acid, 2 Ampicillin, 3 Cefazolin, 4 Cefoperazone, 5 Cefquinome., 6 Ceftiofur, 7 Enrofloxacin, 8 Erythromycin, 9 Florfenicol, 10 Lincomycin, 11 Oxacillin, 12 Penicillin, 13 Tetracycline, 14 Trimethoprim/sulfamethoxazole.…”

“…Although its primary reservoir is the dairy farm environment [5][6][7], some Strep. uberis strains show a contagious transmission mode [8,9], deserving further investigation. Molecular genotyping contributes to understanding the modes of dissemination and can be useful in epidemiological studies of Strep.…”

Bactérias Da Mastite Subclínica Bovina: Suscetibilidade a Antibióticos

“…Streptococcus uberis e S. dysgalactiae estão entre as principais espécies dentro do gênero Streptococcus, relacionadas a mastite subclínica (BI et al, 2016;WALD et al, 2020).…”