Some coagulase-negative Staphylococcus species affect udder health more than others

Abstract

A longitudinal study in 3 dairy herds was conducted to profile the distribution of coagulase-negative Staphylococcus (CNS) species causing bovine intramammary infection (IMI) using molecular identification and to gain more insight in the pathogenic potential of CNS as a group and of the most prevalent species causing IMI. Monthly milk samples from 25 cows in each herd as well as samples from clinical mastitis were collected over a 13-mo period. Coagulase-negative staphylococci were identified to the species level using transfer-RNA intergenic spacer PCR. The distribution of CNS causing IMI was highly herd-dependent, but overall, Staphylococcus chromogenes, Staphylococcus xylosus, Staphylococcus cohnii, and Staphylococcus simulans were the most prevalent. No CNS species were found to cause clinical mastitis. The effect of the most prevalent species on the quarter milk somatic cell count (SCC) was analyzed using a linear mixed model, showing that Staph. chromogenes, Staph. simulans, and Staph. xylosus induced an increase in the SCC that is comparable with that of Staphylococcus aureus. Almost all CNS species were able to cause persistent IMI, with Staph. chromogenes causing the most persistent infections. In conclusion, accurate species identification cannot be ignored when studying the effect of CNS on udder health, as the effect on SCC differs between species and species distribution is herd-specific. Staphylococcus chromogenes, Staph. simulans, and Staph. xylosus seem to be the more important species and deserve special attention in further studies. Reasons for herd dependency and possible cow- and quarter-level risk factors should be examined in detail for the different species, eventually leading to cost-benefit analyses for management changes and, if needed, treatment recommendations.

Intramammary treatment with gentamicin in lactating cows with clinical and subclinical mastitis

“…and Streptococcus spp. These results agree with other studies demonstrating a predominance of these pathogens in cases of bovine mastitis (Tenhagen et al 2006, Supré et al 2011. The rates of isolation of Corynebacterium spp.…”

Quarter- and cow-level risk factors for intramammary infection with coagulase-negative staphylococci species in Swiss dairy cows

“…simulans, and Staph. xylosus were considered the most important CNS species causing IMI (Vanderhaeghen et al, 2015), but patterns of CNS species are frequently herd specific (Piessens et al, 2011;Supré et al, 2011). Within our study herds, a herd-specific pattern was particularly pronounced for the Staph.…”

Evaluation of minor pathogen intramammary infection, susceptibility parameters, and somatic cell counts on the development of new intramammary infections with major mastitis pathogens

“…occurred, which may have limitations. Several types of CNS are found in bovine milk, causing a wide range of chronicity and inflammatory effects in the mammary gland (Supré et al, 2011). Speciation of a subset (n = 1,400) of the CNS-positive samples included here has been completed, and 20 different species of CNS were identified.…”

“…Hence, it would be ideal to be able to use speciated CNS and Corynebacterium spp. samples in the analyses of these data (Supré et al, 2011).…”