Characterization of Coagulase Negative Staphylococci Isolated from Dairy Goats in Germany

Abstract

Over 2 years as a part of a surveillance program, 2038 one half milk samples were collected from dairy goats representing 12 German herds. Microbiological investigation of the samples revealed positive bacterial growth in 17.3% of them. Biochemical identification of the field isolates detected Non-Aureus Staphylococci (NAS) in 10.4%, Corynebacteria in 3.2%, Streptococci in 0.8%, S. aureus in 0.7%, other bacteria in 1.0%. Meanwhile, mixed bacterial growth was shown in 2.2% of the samples. To identify the NAS isolates at their species level the detection of their biochemical properties alone using a commercial test kit enabled the correct identification of a randomized selection of the field isolates only in 11.4%. For further identification, a combination of two other identification techniques (antibiotic resistance profiles and molecular assays) was additionally applied. By doing so, it was possible to identify 69 (58.5%) out of 118 isolated presumptive NAS field strains at their species level. The detected species included S. caprae, S. epidermidis, S. simulans, S. hyicus, S. saprophyticus, S. chromogenes, S. lentus, S. xylosus and S. hominis. Among them, S. caprae was detected most frequently while S. lentus, S. xylosus and S. hominis were isolated only from sporadic cases.

Mastitis in Small Ruminants

“…Non-aureus staphylococci are the most prevalent bacteria from goats with subclinical mastitis, with up to 100% incidence [10,48,[50][51][52]. The most isolated bacteria from these species are Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus simulans, Staphylococcus xylosus, and Staphylococcus caprae [10,[52][53][54].…”

“…Non-aureus staphylococci are the most prevalent bacteria from goats with subclinical mastitis, with up to 100% incidence [10,48,[50][51][52]. The most isolated bacteria from these species are Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus simulans, Staphylococcus xylosus, and Staphylococcus caprae [10,[52][53][54]. S. chromogenes and S. epidemidis are associated with higher milk SCC [53] compared to other non-aureus staphylococci, however, the increase in SCC is lower than in S. aureus mastitis [10].…”