The Role of Streptococcus spp. in Bovine Mastitis

Abstract

The Streptococcus genus belongs to one of the major pathogen groups inducing bovine mastitis. In the dairy industry, mastitis is the most common and costly disease. It not only negatively impacts economic profit due to milk losses and therapy costs, but it is an important animal health and welfare issue as well. This review describes a classification, reservoirs, and frequencies of the most relevant Streptococcus species inducing bovine mastitis (S. agalactiae, S. dysgalactiae and S. uberis). Host and environmental factors influencing mastitis susceptibility and infection rates will be discussed, because it has been indicated that Streptococcus herd prevalence is much higher than mastitis rates. After infection, we report the sequence of cow immune reactions and differences in virulence factors of the main Streptococcus species. Different mastitis detection techniques together with possible conventional and alternative therapies are described. The standard approach treating streptococcal mastitis is the application of ß-lactam antibiotics. In streptococci, increased antimicrobial resistance rates were identified against enrofloxacin, tetracycline, and erythromycin. At the end, control and prevention measures will be considered, including vaccination, hygiene plan, and further interventions. It is the aim of this review to estimate the contribution and to provide detailed knowledge about the role of the Streptococcus genus in bovine mastitis.

Streptococcus dysgalactiae ssp. dysgalactiae in Norwegian bovine dairy herds: Risk factors, sources, and genomic diversity

“…dysgalactiae (SDSD) is an important pathogen of the bovine udder, with the ability to cause severe clinical mastitis, prolonged elevated SCC, and decreased milk yield (Whist et al, 2007;Ericsson Unnerstad et al, 2009;Heikkilä et al, 2018). It is among the major causes of IMI of dairy cows in Norway and several other countries (TINE, 2020;Duse et al, 2021;Kabelitz et al, 2021), and has negative impacts on animal welfare, economy, and antimicrobial use. According to TINE Mastitis Laboratory in Norway, the proportion of milk samples positive for SDSD increased from 6% to 13% between 2002 and 2020 (TINE, 2020).…”

Evaluation of Control Program Against Streptococcus agalactiae Infection in Dairy Herds During 2019–2021 in Emilia-Romagna Region, Northern Italy

“…Raboisson et al ( 1 ) estimated a mean loss of €121 (€103–227) per case of clinical mastitis due to Streptococcus spp. Although milk loss following clinical mastitis (independent of the pathogen) is well documented ( 2 ), pathogen-specific estimates for milk loss and somatic cell count (SCC) due to GBS are currently lacking. In a recent study, the GBS intramammary infection (IMI) was associated with a reduction in milk production yield of 2.5 kg milk/day since 1–2 months before diagnosis and an increase of SCC since 4–5 months before diagnosis ( 3 ).…”

Silver Nanoparticles Targeting the Drug Resistance Problem of Streptococcus dysgalactiae: Susceptibility to Antibiotics and Efflux Effect

“…The antibiotic resistance spreads from eatable animals to humans indirectly via the food chain [ 6 ]. Mastitis is one of the most common and costly diseases in the dairy industry, causing significant economic losses of €124 ($147) per cow per year, resulting in losses of 500 million, 3 billion, and 125 billion € in Germany, the EU, and worldwide, respectively [ 7 ].…”