Invited review: Effect, persistence, and virulence of coagulase-negative Staphylococcus species associated with ruminant udder health

Abstract

The aim of this review is to assess the effect of coagulase-negative staphylococci (CNS) species on udder health and milk yield in ruminants, and to evaluate the capacity of CNS to cause persistent intramammary infections (IMI). Furthermore, the literature on factors suspected of playing a role in the pathogenicity of IMI-associated CNS, such as biofilm formation and the presence of various putative virulence genes, is discussed. The focus is on the 5 CNS species that have been most frequently identified as causing bovine IMI using reliable molecular identification methods (Staphylococcus chromogenes, Staphylococcus simulans, Staphylococcus haemolyticus, Staphylococcus xylosus, and Staphylococcus epidermidis). Although the effect on somatic cell count and milk production is accepted to be generally limited or nonexistent for CNS as a group, indications are that the typical effects differ between CNS species and perhaps even strains. It has also become clear that many CNS species can cause persistent IMI, contrary to what has long been believed. However, this trait appears to be quite complicated, being partly strain dependent and partly dependent on the host's immunity. Consistent definitions of persistence and more uniform methods for testing this phenomenon will benefit future research. The factors explaining the anticipated differences in pathogenic behavior appear to be more difficult to evaluate. Biofilm formation and the presence of various staphylococcal virulence factors do not seem to (directly) influence the effect of CNS on IMI but the available information is indirect or insufficient to draw consistent conclusions. Future studies on the effect, persistence, and virulence of the different CNS species associated with IMI would benefit from using larger and perhaps even shared strain collections and from adjusting study designs to a common framework, as the large variation currently existing therein is a major problem. Also within-species variation should be investigated.

Technical note: A pilot study using a mouse mastitis model to study differences between bovine associated coagulase-negative staphylococci

“…In essence, 12 CNS species are frequently isolated from bovine milk. Evidence exists for diversity between and even within those species in their epidemiologic behavior and traits, such as persistence, antibiotic resistance, susceptibility to phagocytosis by mouse macrophages, and (putative) virulence (Piessens et al, 2011;Supré et al, 2011;Avall-Jääskeläinen et al, 2013;Vanderhaeghen et al, 2014).…”

Milk quality characteristics from Greek indigenous goats

“…CNS have been recognized as an heterogenous group of microorganisms and increased attention will be given to dairy flocks with frequent intramammary infections (Tzora et al, 2014;Vanderhaeghen et al, 2015). However, the pathogenic role of CNS is complex and some CNS species / strains might have a beneficial effect on udder health (Vanderhaeghen et al, 2014). Therefore, improving hygienic conditions during milking is an essential step towards limiting microbiological hazards (Lodi et al, 1994).…”

Persistência De Staphylococcus Coagulase-Negativos Em Glândulas Mamárias De Ovelhas Com Mastite Subclínica Após O Tratamento Antimicrobiano À Secagem

“…Estes achados diferem em parte dos relatados por Vanderhaeghen et al (16) , que mencionaram como espécie de maior ocorrência S. chromogenes, além de S. simulans, S. xylosus, S. haemolyticus e S. epidermidis, mas não consideraram S. warneri entre as espécies mais prevalentes. Em rebanho localizado no estado de Santa Catarina, Dall Agnol et al (17) relataram a presença de S. epidermidis e S. simulans na etiologia infecciosa da mastite ovina e não identificaram S. warneri dentre as espécies isoladas.…”