Characterization of Prototheca zopfii Genotypes Isolated from Cases of Bovine Mastitis and Cow Barns in China
Characterization of Prototheca zopfii Genotypes Isolated from Cases of Bovine Mastitis and Cow Barns in China
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从中国牛乳腺炎病例和牛舍中分离的 Prototheca zopfii 基因型特征
DOI：
10.1007/s11046-015-9951-9
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发表时间：
2016-04-01
期刊：
影响因子：
5.5
通讯作者：
Han, Bo
中科院分区：
文献类型：
--
作者：
Shahid, Muhammad;Ali, Tariq;Han, Bo
原鞘性乳腺炎，主要由zopfii原鞘菌（P. zopfii）引起，正在奶牛群中增加，并在全球范围内报道。采用微生物学、生物化学和分子生物学方法，对中国三省奶牛群及其周围环境中分离的猪粪卟啉卟啉（P. zoopfii）进行了流行病学研究，并进行了抗生素敏感性试验。分析了乳牛乳（n = 620）及其畜舍源（n = 410）的粪便、饲料、垫料和饮用水样品。在从乳乳中回收的其他病原菌中，84株（13.5%）被鉴定为zopfii。从牛奶中分离得到的zopfii均为基因2型，从环境源分离得到的zopfii基因1型和2型分别为58株（73.4%）和21株（26.6%）。对阿米卡星（78.1%）、链霉素（58.5%）、庆大霉素（17.8%）、两性霉素B（68.6%）、制霉菌素（64.4%）等抗生素和抗真菌药物敏感。此外，这两种基因型对不同的抗菌剂表现出不同的易感性模式。以18S SSU rDNA和28S SSU rDNA为基础，研究了基因型的系统发育。两种基因型的分离株分属不同的进化支，系统发育分析表明，两种基因型之间没有相互关系。来自牛棚源的基因1型分离株是非致病性的，可能不会出现任何乳腺炎的风险。本研究认为，zopfip基因2型可能在中国牛乳腺炎中起重要作用。
Protothecal mastitis, caused mostly by Prototheca zopfii (P. zopfii), is increasing in dairy herds and is being reported globally. The present study was aimed at studying the epidemiology of mastitis and at molecular characterization of P. zopfii isolates from dairy herds and their surroundings in three provinces of China using microbiological, biochemical and molecular methods, and antibiotic susceptibility tests. Samples from milk (n = 620) of mastitic cows and their barns sources (n = 410) including feces, feed, bedding materials and drinking water were analyzed. Among other pathogens recovered from mastitic milk, 84 (13.5 %) of the isolates were identified as P. zopfii. All of the P. zopfii isolates recovered from milk were recognized as genotype 2, whereas 58 (73.4 %) and 21 (26.6 %) isolates from environmental sources were found to be P. zopfii genotypes 1 and 2, respectively. The isolates were susceptible to some antibiotics and antifungal agents, including amikacin (78.1 %), streptomycin (58.5 %), gentamicin (17.8 %), amphotericin B (68.6 %) and nystatin (64.4 %). Additionally, the two genotypes displayed versatile patterns of susceptibility to different antimicrobials agents. Phylogeny of the genotypes on the basis of 18S SSU rDNA and 28S SSU rDNA was also investigated. The isolates of the two genotypes separated into different clades, and no interrelationship was observed among these as shown by phylogenetic analysis. The genotype 1 isolates from cow barn sources were non-pathogenic and may not present any risk of mastitis. We conclude that P. zopfii genotype 2 might play an important role in bovine mastitis in China.