Abstract:
Trueperella (T.) pyogenes is a mastitis-causing pathogen formerly known to cause severe clinical mastitis (CM), especially during the summer, leading to milk losses and low recovery rates. Unfortunately, its transmission behavior within herds is unclear. The diversity and occurrence of T. pyogenes were monitored to gain an initial insight into the infection transmission behavior of T. pyogenes in dairy herds and to lay a foundation for following targeted investigations. CM milk samples were collected from German herds, and one Swedish farm was sampled for isolates from subclinical mastitis. All in all, 151 T. pyogenes isolates from 16 herds were isolated, identified by MALDI TOF analysis and typed with RAPD PCR. Of these, 17 isolates originated from subclinical mastitis cases. We found that T. pyogenes mastitis occurred year-round, and clinical mastitis cases were caused by multiple strains (31 affected animals/28 strains). Instances of multiple cows being infected with the same T. pyogenes strain were rare and typically only involved a small number of animals at a time. However, if several quarters of a cow were affected, it was likely the same strain. Unlike clinical infections, subclinical T. pyogenes infections, in one investigated farm, harbored a dominant strain. Additionally, we found that T. pyogenes infections tended to persist and stay within a herd for a minimum of 7 months in the same or different cows.
摘要:
Trueperella(T.)化脓性是一种引起乳腺炎的病原体,以前已知会引起严重的临床乳腺炎(CM),尤其是在夏天,导致牛奶损失和低回收率。不幸的是,它在牛群内的传播行为尚不清楚。对化脓性产脓毒菌的多样性和发生进行了监测,以初步了解化脓性产脓毒菌在奶牛群中的感染传播行为,并为后续有针对性的调查奠定基础。CM牛奶样品是从德国牛群中收集的,并对一个瑞典农场进行了亚临床型乳腺炎分离株的取样。总而言之,从16个畜群中分离出151个化脓性产热杆菌,通过MALDITOF分析鉴定,并用RAPDPCR分型。其中,17个分离株起源于亚临床型乳腺炎病例。我们发现化脓性支原体乳腺炎全年发生,临床乳腺炎病例是由多种菌株引起的(31只受累动物/28株)。多头母牛感染相同的化脓性产热杆菌菌株的情况很少见,通常一次只涉及少量动物。然而,如果四分之一的奶牛受到影响,很可能是同样的菌株。与临床感染不同,亚临床化脓性衣原体感染,在一个被调查的农场里,带有优势菌株。此外,我们发现,在相同或不同的奶牛中,化脓性芽孢杆菌感染倾向于持续并在牛群中停留至少7个月。