Vaidya V M, Malik S V S, Kaur Simranpreet, Kumar Satish, Barbuddhe S B
Division of Veterinary Public Health, National Biotechnology Centre, Indian Veterinary Research Institute, Izatnagar, India.
J Clin Microbiol. 2008 Jun;46(6):2038-44. doi: 10.1128/JCM.01874-07. Epub 2008 Apr 30.
Coxiella burnetii, an obligate intracellular parasite with a worldwide distribution, is the causative agent of Q fever in humans. We tested a total of 368 samples (placental bits, genital swabs, fecal swabs, and urine and serum samples) collected from women (n = 74) with spontaneous abortions for C. burnetii by a PCR assay targeting IS1111, the repetitive transposon-like region of C. burnetii (trans-PCR); real-time PCR; an indirect immunofluorescence assay (IFA); and the isolation of the pathogen. The IFA showed seropositivity for 25.68% of the women with spontaneous abortions, whereas trans-PCR and real-time PCR each detected the pathogen in 21.62% of cases. Overall, 25.68% of the subjects were positive by one or more assays. Real-time PCR showed a slightly higher level of sensitivity than trans-PCR. With the IFA as the reference, the two PCR assays showed a higher level of sensitivity (84.21%) than pathogen isolation (26.31%), while both the PCR assays and pathogen isolation were specific (100%). The detection of high numbers of C. burnetii cells in clinical samples and the frequent association of the pathogen with cases of spontaneous abortions observed in this study revealed that Q fever remains underdiagnosed and that the prevalence in India is underestimated.
伯纳特柯克斯体是一种专性细胞内寄生菌，在全球范围内均有分布，是人类Q热的病原体。我们通过针对伯纳特柯克斯体重复转座子样区域IS1111的PCR检测法（转座子PCR）、实时PCR、间接免疫荧光法（IFA）以及病原体分离，对从74名自然流产女性中采集的共计368份样本（胎盘组织、生殖道拭子、粪便拭子、尿液和血清样本）进行了伯纳特柯克斯体检测。IFA显示25.68%的自然流产女性血清呈阳性，而转座子PCR和实时PCR在各21.62%的病例中检测到了病原体。总体而言，25.68%的受试者通过一种或多种检测呈阳性。实时PCR显示出比转座子PCR略高的灵敏度水平。以IFA为参照，两种PCR检测法显示出比病原体分离（26.31%）更高的灵敏度水平（84.21%），而PCR检测法和病原体分离均具有特异性（100%）。本研究中在临床样本中检测到大量伯纳特柯克斯体细胞以及该病原体与自然流产病例的频繁关联表明，Q热仍未得到充分诊断，且印度的患病率被低估。
