宁夏地区临床型奶牛乳房炎非白色念珠菌分离株生物学特性分析  

Biological characteristics of clinical isolates other than Candida albicans causing bovine mastitis in Ningxia

作　　者：马生妍 王晓禹 周学章 MA Sheng-yan;WANG Xiao-yu;ZHOU Xue-zhang(Key Laboratory of Conservation and Utilization of Western Characteristic Biological Resources,Ministry of Education,Ningxia University,Yinchuan,China 750021)

机构地区：[1]宁夏大学西部特色生物资源保护与利用教育部重点实验室,宁夏银川750021

出　　处：《中国病原生物学杂志》2020年第4期410-415,420,共7页Journal of Pathogen Biology

基　　金：国家自然科学基金项目(No.31660728)。

摘　　要：目的了解宁夏地区奶牛乳房炎非白色念珠菌临床分离株的生物学特性,为诊断和治疗奶牛真菌性乳房炎提供理论依据。方法采集宁夏地区奶牛乳房炎乳样中分离鉴定的克柔念珠菌(CK1)、近平滑念珠菌(CP1)、近邹褶念珠菌(CA1)等非白色念珠菌(NAC)并进行RAPD分型和聚类分析,通过对表性转换、溶血活性、磷脂酶活性以及细胞表面疏水性测定,分析奶牛乳房炎非白色念珠菌分离株生物学特性,采用药敏纸片法对常用抗真菌药物进行药敏试验。结果Ck1与Cp1两者间的遗传相似系数为0.3394,Ck1与Ca1两者遗传相似系数为0.4312,可见近邹褶念珠菌与克柔氏念珠菌两者间的遗传背景较接近;这3种NAC均具有菌丝形成的能力、细胞表面疏水性及溶血活性,近平滑念珠菌溶血活性较强,克柔氏念珠菌尤其是分离株的细胞表面疏水性较强。近平滑念珠菌检测到磷脂酶阳性;药敏试验发现,奶牛乳房炎分离株对常用抗真菌药物尤其是唑类药物存在较严重的耐药性,以CK1尤为严重,4种耐药基因均出现较高表达,与MIC值测定结果相吻合。氟康唑联合两性霉素B具有协同抗近平滑念珠菌作用;5-氟胞嘧啶联合两性霉素B和酮康唑具有协同抗近邹褶念珠菌作用。结论宁夏地区奶牛乳房炎非白色念珠菌分离株对常用抗真菌药物存在严重耐药性,3种NAC均具有菌丝形成的能力、细胞表面疏水性及溶血活性,近平滑念珠菌检测到磷脂酶。克柔念珠菌分离株CK1对5种抗真菌药物交叉耐药率高,联合使用可提高抗真菌效果。Objectives To ascertain the biological characteristics of clinical isolates other than Candida albicans cau-sing dairy cow mastitis in Ningxia and to provide a theoretical basis for the diagnosis and treatment of fungal mastitis in dairy cows.Method Strains other than Candida albicans(NCA)such as Candida krusei(CK1),C.parapsilosis(CP1),and C.pararugosa(CA1)were isolated and identified from milk samples from cows with mastitis in Ningxia.The RAPD classification,cluster analysis,hemolytic activity,phospholipase activity and cell surface hydrophobicity of the strains were determined to analyze the biological characteristics of NCAs.The susceptibility of NCA isolates to common antifungals was also determined.Result Results indicated that the genetic similarity coefficient between Ck1and Cp1was 0.3394and that between Ck1and Ca1was 0.4312.This result implies a close genetic background between C.pararugosa and C.krusei.All three NCAs have the ability to form hyphae,cell surface hydrophobicity,and hemolytic activity.However,C.parapsilosis had more greater hemolytic activity,C.krusei,and especially the isolates,had a more hydrophobic cell surface,and C.parapsilosis was positive for phospholipase.The drug susceptibility test indicated that the dairy cow mastitis isolates were highly resistant to common antifungals,and especially azoles.CK1was most resistant and had a higher level of expression of the four drug resistance genes CDR1,CDR2,ERG11,and MDR1.Those findings were consistent with the results of MIC determination.The FICI of fluconazole combined with amphotericin B was 0.125-0.25,and the combination had a synergistic effect on C.parapsilosis.The FICI of 5-fluorocytosine com-bined with amphotericin B was 0.25,and the FICI of 5-fluorocytosine combined with ketoconazole was 0.5;both had a synergistic effect on C.pararugosa.Conclusion Results revealed the biological characteristics of mastitis due to NCAs in dairy cows in Ningxia.All three NCAs have the ability to form hyphae,cell surface hydrophobicity,and hemolytic act

关 键 词：非白色念珠菌 奶牛乳房炎 毒力因子 耐药性 

分 类 号：R379.4[医药卫生—病原生物学]