The aim of this study was to determine the prevalence of
Streptococcus (
Sc.)
agalactiae,
Prototheca spp.,
Staphylococcus (
S.)
aureus, and especially methicillin-resistant
S. aureus as well as
Myco-plasmopsis (
M.) spp. and
M. bovis in bulk
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The aim of this study was to determine the prevalence of
Streptococcus (
Sc.)
agalactiae,
Prototheca spp.,
Staphylococcus (
S.)
aureus, and especially methicillin-resistant
S. aureus as well as
Myco-plasmopsis (
M.) spp. and
M. bovis in bulk tank milk (BTM) on dairy farms in Lower Saxony, Germany. BTM samples were collected in January 2023 from 208 selected dairy farms. The samples were quantitatively culturally analyzed for
S. aureus and
Prototheca spp. Presumptive
S. aureus colonies were further confirmed by MALDI-TOF. Presumptive
Prototheca spp. colonies were confirmed by light microscopy.
Sc. agalactiae and
Mycoplasmopsis spp. were detected by real-time polymerase chain reaction (rtPCR).
Sc. agalactiae was detected in two herds (1% (Confidence Interval 95% (CI) 0.3–3.4)).
S. aureus was confirmed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) in 38 herds (18.3% (CI 13.6–24.1)), assuming a threshold of >10 cfu/mL milk. A total of 154 isolates identified as
S. aureus by MALDI-TOF were transferred to agar with added oxacillin for resistance testing, of which 19 isolates (12.3% (CI 8–18.5)) showed growth. The 19 isolates came from eight different farms (3.8% (2–7.4)).
Prototheca spp. were identified in 13 herds (6.3% (CI 3.7–10.4)).
Mycoplasmopsis spp. were detected by PCR in 18 herds (8.7% (CI 5.5–13.3)). Of these,
M. bovis was present in three herds (1.4% (0.5–4.2)). The herd prevalence of
Sc. agalactiae in BTM appears to be at low levels in the sampled area. The prevalence of
Mycoplasmopsis spp. in the herds was higher than expected compared to previous studies. It is interesting to note that the percentage of
M. bovis in the total
Mycoplasmopsis spp. was only 16.7%.
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