鸽源白色念珠菌的分离鉴定及药物敏感性分析

Isolation,Identification and Antifungal Susceptibility Analysis of Candida albicans Isolated from Pigeons

重庆某鸽场1~3周龄幼鸽喉头出现大块干酪样物,堵塞喉头,导致无法进食并陆续死亡。本研究旨在鉴定导致该鸽场大批幼鸽发病的病原。在病鸽喉头、嗉囊、腺胃、肠道等部位采集病料,接种含1%庆大霉素PDA平板分离病原,采用革兰染色、棉蓝染色、芽管生成试验和PCR扩增鉴定病原。分离的病原菌进行动物回归试验和药物敏感性试验。最终在5只病鸽分离到8株革兰染色呈卵圆形、黑色或粉紫色的革兰阳性酵母样菌体,棉蓝染色结果显示菌体长出菌丝和孢子。这些真菌在含1%庆大霉素PDA平板上生长为乳白色、边缘整齐的光滑菌落,在胎牛血清中孵育能生成芽管,能扩增出白色念珠菌特异rDNA基因间转录间隔区序列。动物回归试验结果显示分离菌株能导致雏鸡嗉囊肿胀,嗉囊鳞状上皮细胞变性、坏死、脱落。药物敏感性试验显示分离菌对两性霉素B、制霉菌素和克霉唑敏感。本研究确定了导致鸽场发病的病原为白色念珠菌,且分离菌在体外对部分抗真菌药物敏感。

One to three week old pigeons from a farm in Chongqing had large pieces of cheese-like substances in their throats,causing pigeons’throats to be blocked,resulting in inability to eat and death in succession.The purpose of this study was to identify the pathogens that caused the disease of a large number of young pigeons.The pathogen was isolated from the throat,crop,glandular stomach and intestines of diseased pigeons.The samples were collected from the throat,crop,glandular stomach and intestines of diseased pigeons,and inoculated on PDA plates containing 1% gentamicin to isolated pathogens.Pathogens were identified by gram staining,cotton blue staining,germ tube test,and PCR amplification.Animal regression test and antifungal susceptibility were carried out.Eight gram-positive yeast-like cells with oval,black or purple pink color were isolated from 5 diseased pigeons.The results of cotton blue staining showed that mycelia and spores grew from the isolates.These isolates were milky white smooth colonies with neat edges on PDA plates containing 1% gentamicin.When incubated in fetal bovine serum,they can grow into germ tubes.Transcriptional spacer sequence of Candida albicans specific rDNA genes were amplified from the isolates.The results of animal regression test showed that the isolated strains causes swelling of crops,and the degeneration,necrosis and abscission of crops’squamous epithelial cells.The antifungal susceptibility testing showed that the isolates were susceptible to amphotericin B,nystatin and clotrimazole.In this study,Candida albicans was identified as the pathogen of pigeons at a pigeon farm in Chongqing,and the Candida albicans isolates were susceptible to some antifungal drugs in vitro.