Università degli Studi di Milano, Department of Veterinary Pathology, Hygiene and Public Health, Milan, Italy.
J Dairy Sci. 2011 Sep;94(9):4574-7. doi: 10.3168/jds.2011-4294.
The present study was undertaken during an outbreak of clinical and subclinical mastitis in 14 dairy cows caused by Candida rugosa, in which high somatic cell counts were seen and cases did not respond to antibiotic treatment. Intramammary infection cured spontaneously in 10 cows, whereas 4 cows were culled as a result of persistent infections. Repeated sampling of these cows and biomolecular analysis of the isolates showed that the infections were caused by the same genotype, even over a period of 2 lactations. Random amplification of the genome of C. rugosa milk isolates gave 3 different DNA banding patterns (genotypes G1, G2, and G3). Viable cells of C. rugosa were also isolated from various environmental sources and were present in high concentrations in total mixed ration samples, which could be considered the primary source of diffusion of viable yeast cells in the environment, as demonstrated by genotyping. The proven capacity of these microorganisms to survive in the environment of the cow, such as the total mixed ration, bedding, water, and cow skin, and to cause persistent intramammary infections highlights the importance of mycotic spread in dairy herds.
本研究在 14 头奶牛中进行，这些奶牛患有由假丝酵母菌引起的临床和亚临床乳腺炎，其体细胞计数较高，且对抗生素治疗无反应。10 头奶牛的乳房感染自发痊愈，而 4 头奶牛由于持续感染而被淘汰。对这些奶牛进行重复采样和分离物的生物分子分析表明，感染是由相同的基因型引起的，甚至在两个泌乳期内也是如此。假丝酵母菌乳样分离物基因组的随机扩增产生了 3 种不同的 DNA 带型（基因型 G1、G2 和 G3）。假丝酵母菌的活细胞也从各种环境来源中分离出来，并存在于总混合日粮样品中，其浓度很高，可被认为是活酵母细胞在环境中扩散的主要来源，这一点通过基因型得到了证实。这些微生物在奶牛环境（如总混合日粮、垫料、水和奶牛皮肤）中生存并引起持续的乳房内感染的能力，突出了真菌在奶牛群中传播的重要性。
