Epidemiology of Mycoplasma agalactiae and Mycoplasma mycoides cluster in flocks of northeastern Brazil

ABSTRACT: The present study aimed to investigate contagious agalactia (CA) in flocks from Pernambuco State. The study involved 225 goats and 63 ewes; 288 milk samples and 100 vaginal swabs were collected in total. The PCR assays were carried out using specific primers to Mycoplasma agalactiae and the Mycoplasma mycoides cluster. Among the goat’s milk samples,12.0% (27/225) were positive for Mycoplasma agalactiae DNA, while 5.3% (12/225) contained the Mycoplasma mycoides cluster. Of the vaginal swabs taken from goats, 15.4% (12/78) were positive for Mycoplasma agalactiae DNA and 3.8% (3/78) contained the Mycoplasma mycoides cluster. In the case of ewes, 4.3% (1/23) of the milk samples contained Mycoplasma agalactiae DNA, and 7.5% (3/40) were positive for the Mycoplasma mycoides cluster. Vaginal swabs taken from sheep´s were negative. Analysis of risk factors for mycoplasmosis, showed that goats and sheep flocks on the extensive breeding system are more likely to have mycoplasmosis than those on the intensive breeding system (odds ratio (OR) 6.2; p=0.004); meat goat and sheep flocks are more likely to have infection compared to dairy flocks (OR 4.8; p=0.011); unclean animal housing increases the chances of infection (OR 5.0; p=0.031) and not performing quarantine increases the chances of mycoplasmosis (OR 4.6; p=0.042). Based on these findings we conclude that CA syndrome in the semiarid region of Pernambuco state can be associated with Mycoplasma agalactiae and Mycoplasma mycoides cluster.

摘要：本研究旨在调查佩尔南布科州（Pernambuco State）羊群中的接触性无乳症（contagious agalactia, CA）。本研究共纳入225只山羊与63只母绵羊，总计采集288份乳汁样本与100份阴道拭子样本。本研究采用针对无乳支原体（Mycoplasma agalactiae）与丝状支原体簇（Mycoplasma mycoides cluster）的特异性引物开展聚合酶链式反应（PCR）检测。在山羊乳汁样本中，12.0%（27/225）的样本检测出无乳支原体DNA阳性，5.3%（12/225）的样本呈丝状支原体簇阳性。在采集自山羊的阴道拭子样本中，15.4%（12/78）的样本无乳支原体DNA检测呈阳性，3.8%（3/78）的样本呈丝状支原体簇阳性。针对母绵羊而言，其乳汁样本中4.3%（1/23）检测出无乳支原体DNA，7.5%（3/40）的样本呈丝状支原体簇阳性；采集自母绵羊的阴道拭子样本检测结果均为阴性。对支原体病相关危险因素的分析显示，采用粗放养殖模式的山羊与绵羊群，其支原体病感染风险显著高于集约化养殖群体（优势比（odds ratio, OR）=6.2；p=0.004）；肉用山羊与绵羊群的感染风险同样高于奶用畜群（OR=4.8；p=0.011）；畜舍卫生状况不佳会提升感染风险（OR=5.0；p=0.031），而未实施检疫措施则会增加支原体病的发病概率（OR=4.6；p=0.042）。基于上述研究结果，本研究得出结论：佩尔南布科州半干旱地区的接触性无乳症综合征与无乳支原体及丝状支原体簇存在关联。