Exel Catharina Elizabeth, Geus Yvette de, Spaninks Mirlin, Koop Gerrit, Benedictus Lindert
Department Population Health Sciences, Division Farm Animal Health, Utrecht University, Yalelaan, 7, 3584 CL Utrecht, The Netherlands.
Department Population Health Sciences, Division Institute for Risk Assessment Sciences, Utrecht University, Yalelaan, 7, 3584 CL Utrecht, The Netherlands.
Pathogens. 2023 Mar 26;12(4):515. doi: 10.3390/pathogens12040515.
(), a major mastitis pathogen in dairy goats, is classified as a contagious pathogen. Although previous research has shown that extramammary body sites can be colonized with , it is unknown whether these sites are reservoirs for intramammary infections. The aim of this research was to determine whether extramammary sites can be colonized with mastitis-associated strains in dairy goats. Milk samples were collected from 207 primiparous goats and from 120 of these goats, extramammary site samples (hock, groin, nares, vulva and udder) were collected from a large commercial dairy goat herd in the Netherlands during four sampling visits. Extramammary site swabs and milk samples were (selectively) cultured and isolates were genotyped. The prevalence of colonization of the extramammary sites at goat level was 51.7% and the prevalence of intramammary infections was 7.2%. The nares were colonized most frequently (45%), while the groin area was colonized the least (2.5%). Six genotypes were identified in this herd and there was no significant difference in the distribution of genotypes between the milk or the extramammary sites ( = 0.141). Both in the extramammary sites and in the milk, genotypes t544 (82.3% and 53.3%) and t1236 (22.6% and 33.3%) were the dominant genotypes. These results show that in goats, extramammary sites, particularly the nares, are frequently colonized with mastitis-associated strains. Extramammary sites may, thus, be a source of intramammary infections that are not targeted by the intervention measures aimed at preventing transmission from infected udder glands.
无乳链球菌是奶山羊乳腺炎的主要病原菌，被归类为传染性病原菌。尽管先前的研究表明乳腺外身体部位可被无乳链球菌定植，但这些部位是否为乳腺内感染的储存库尚不清楚。本研究的目的是确定奶山羊的乳腺外部位是否可被与乳腺炎相关的无乳链球菌菌株定植。从207只初产山羊采集乳样，并从其中120只山羊在荷兰一个大型商业化奶山羊群的四次采样过程中采集乳腺外部位样本（跗关节、腹股沟、鼻孔、外阴和乳房）。对乳腺外部位拭子和乳样进行（选择性）培养，并对无乳链球菌分离株进行基因分型。山羊水平上乳腺外部位的定植率为51.7%，无乳链球菌乳腺内感染率为7.2%。鼻孔定植最为频繁（45%），而腹股沟区域定植最少（2.5%）。在该羊群中鉴定出六种无乳链球菌基因型，且无乳链球菌基因型在乳样或乳腺外部位之间的分布无显著差异（P = 0.141）。在乳腺外部位和乳样中，无乳链球菌基因型t544（82.3%和53.3%）和t1236（22.6%和33.3%）均为优势基因型。这些结果表明，在山羊中，乳腺外部位，尤其是鼻孔，经常被与乳腺炎相关的无乳链球菌菌株定植。因此，乳腺外部位可能是乳腺内感染的一个来源，而旨在预防感染乳腺传播的干预措施并未针对该来源。
