Sequence Types and Antimicrobial Resistance Profiles of Streptococcus uberis Isolated From Bovine Mastitis

Abstract

Bovine mastitis is one of the most common diseases among dairy cows and causes high economic losses in dairy industries worldwide. Streptococcus uberis is one of the most frequently identified pathogens causing the disease. In this study, 153 S. uberis strains isolated from mastitis milk samples were analyzed for their genetic diversity using multi locus sequence typing (MLST). Moreover, antibiotic susceptibility testing was performed using a microdilution assay and 11 antimicrobial agents including penicillin, which is the first line agent for treatment of bovine mastitis in Switzerland. MLST was successful for 152 (99.3%) of the strains. Overall, 103 different sequence types (STs) were determined, including 91 novel STs. S. uberis belonging to clonal complex (CC) 5 represented 47 (30.7%) of the mastitis cases. Two (1.3%) of the strains belonged to CC86 and one (0.7%) to CC143. The population structure identified in this work suggests that environmental transmission is the predominant route of infection in herds in Switzerland. Antimicrobial susceptibility testing determined a resistance rate of 11.8% for pirlimycin and elevated MIC90-values for marbofloxacin as well as for erythromycin. This study highlights the importance of genetic characterization of S. uberis and the need for veterinary breakpoints for surveillance of antimicrobial resistance in S. uberis .

Sequence characterisation and novel insights into bovine mastitis-associated Streptococcus uberis in dairy herds

“…There were a limited number of antibiotic resistance genes found in this study. This finding is consistent with some previous dairy herd surveys 9 , but inconsistent with others that detected a broad and diverse group of antibiotic resistance genes 13,87,88 . Four S. uberis isolates found across Victoria and Queensland herds contained a combination of InuC and a multidrug resistance cluster including mel/mef(A), mrsE, vatD and lnuD.…”

Characterization of the Bacteriophage-Derived Endolysins PlySs2 and PlySs9 with In Vitro Lytic Activity against Bovine Mastitis Streptococcus uberis

“…This infection is typically caused by a large variety of microorganisms and has either a clinical or subclinical outcome. Mastitis is frequently caused by the Gram-positive pathogen Streptococcus uberis [ 3 , 4 , 5 ]. Although good hygiene practices during the milking process diminish the incidence of streptococcal bovine mastitis, a full eradication proves impossible [ 6 ].…”

“…Therefore, the milk of treated animals has to be discarded, resulting in food waste and a negative impact on the environment [ 10 ]. Last but not least, the emerging risk of antibiotic resistance development in the dairy industry drives the search for alternative and superior solutions [ 3 , 13 ]. With the consumer’s demand moving towards more sustainable dairy products, the role of antibiotics as a preventive and therapeutic measure in this sector is increasingly questioned.…”

Identification of Key Candidate Genes in Dairy Cow in Response to Escherichia coli Mastitis by Bioinformatical Analysis

“…For example, bovine mastitis caused mostly by bacterial infection, resulting in losses of up to $2 billion per year in the United States alone. Aside from the economic losses, mastitis can impair animal welfare, and poses a threat to human health since it may be responsible for transfer of antimicrobial resistance and for food poisoning (Johler et al, 2015;Käppeli et al, 2019). Escherichia coli (E. coli) which as a prevalent environmental pathogen that routinely colonizes dairy cattle is one of the main pathogens causing mastitis (Buitenhuis et al, 2011).…”