College of Veterinary Medicine, China Agricultural University, Yuan Ming Yuan West Road No.2, Haidian District, Beijing, China.
Mycopathologia. 2012 Apr;173(4):275-81. doi: 10.1007/s11046-011-9510-y. Epub 2011 Dec 10.
Prototheca zopfii (P. zopfii) has become an important cause of bovine mastitis in many countries. In the present study, to better understand the occurrence of one clinical mastitis (CM) outbreak due to P. zopfii, the molecular characterization and resistance patterns of the microalga were described. P. zopfii strains were isolated from 17 of 23 quarters, which suffered CM in the outbreak, and 7 of 46 CM recovered quarters before the outbreak, as well as 2 of 75 environmental samples in the dairy farm. All strains were identified as genotype 2 by genotype-specific PCR analysis. Results of in vitro antimicrobial and antifungal susceptibility tests indicated that these strains were resistant to majority of tested drugs, with the only exception of amphotericin B, nystatin, streptomycin, gentamicin, and amikacin. This is the first report about CM outbreak caused by P. zopfii in China. These data suggest that P. zopfii may represent a serious risk in the studied herd, and this microalga could be an important potential pathogen causing mastitis in dairy herds of Beijing.
胶状念珠藻（P. zopfii）已成为许多国家奶牛乳腺炎的重要病因。在本研究中，为了更好地了解由 P. zopfii 引起的一次临床乳腺炎（CM）暴发的发生情况，对微藻的分子特征和耐药模式进行了描述。从暴发期间发生 CM 的 23 个乳区中的 17 个乳区，以及暴发前从 46 个 CM 恢复乳区中的 7 个乳区和奶牛场的 75 个环境样本中分离到了 P. zopfii 菌株。所有菌株均通过基因型特异性 PCR 分析鉴定为基因型 2。体外抗菌和抗真菌药敏试验结果表明，这些菌株对大多数测试药物具有耐药性，仅对两性霉素 B、制霉菌素、链霉素、庆大霉素和阿米卡星敏感。这是中国首次报道由 P. zopfii 引起的 CM 暴发。这些数据表明，P. zopfii 可能是研究牛群中的一个严重风险因素，这种微藻可能是引起北京奶牛乳腺炎的一个重要潜在病原体。
