Mycoplasma bovis infection in dairy herds-Risk factors and effect of control measures.

As Mycoplasma bovis spreads to new countries and becomes increasingly recognized as a disease with major welfare and economic effects, control measures on dairy farms are needed. To minimize the risk of infection spread to naive herds, all possible risk factors for M. bovis infection should be identified and controlled. Mycoplasma bovis was first diagnosed in dairy cattle in Finland in 2012, and by January 2020, 86 Finnish dairy farms (<1.5%) supporting M. bovis infections were identified. We evaluated risk factors for M. bovis infection using a questionnaire provided to 40 infected and 30 control dairy farms. Control measures were advised for 19 of the infected dairy farms during visits by a veterinarian. The course of the infection on those farms was followed by analyzing calf nasal swabs with PCR for presence of M. bovis 4 times at 6-mo intervals. Control measures included culling of M. bovis mastitic cows, isolation of new calves from older animals after initial M. bovis mastitic cows had been culled, prevention of nose-to-nose contact with infected animals, early detection of mastitis cases using M. bovis PCR, and hygiene measures mainly related to milking, calf pens, feeding buckets, and teats. Farms implemented the control measures related to the isolation of calves or avoidance of nose-to-nose contact in various ways, according to farm structures and financial circumstances.In our study, the control measures recommended to the dairy farms appeared effective, such that 13 of 19 farms reached a low risk level during at least 3 consecutive negative samplings from calves, with no M. bovis mastitis detected subsequently. Among risk factors, insemination with an M. bovis-positive bull indicated a trend of increasing the odds of M. bovis infection on the farm in a multivariable logistic model. In contrast, higher herd average milk yield had an association with lower odds for M. bovis infection. Occurrence of other infectious diseases affecting several animals on the dairy farm in the previous 6 mo before M. bovis infection were more frequent on M. bovis-infected farms.

Streptococcus agalactiae Serotype IV in Humans and Cattle, Northern Europe1.

Streptococcus agalactiae is an emerging pathogen of nonpregnant human adults worldwide and a reemerging pathogen of dairy cattle in parts of Europe. To learn more about interspecies transmission of this bacterium, we compared contemporaneously collected isolates from humans and cattle in Finland and Sweden. Multilocus sequence typing identified 5 sequence types (STs) (ST1, 8, 12, 23, and 196) shared across the 2 host species, suggesting possible interspecies transmission. More than 54% of the isolates belonged to those STs. Molecular serotyping and pilus island typing of those isolates did not differentiate between populations isolated from different host species. Isolates from humans and cattle differed in lactose fermentation, which is encoded on the accessory genome and represents an adaptation to the bovine mammary gland. Serotype IV-ST196 isolates were obtained from multiple dairy herds in both countries. Cattle may constitute a previously unknown reservoir of this strain.