北京市宠物猫和流浪猫巴尔通体感染状况调查

Investigation of infection with Bartonella in domestic and feral cats in Beijing, China

目的调查北京市宠物猫和流浪猫巴尔通体感染状况。方法采集猫的抗凝血和血清并收集相关流行病学信息。将抗凝血用灭菌胰酶大豆肉汤按1∶4稀释后,取100μl接种于含5%去纤维羊血的脑心浸液培养基上,置于37℃、含5%CO2培养箱中分离培养至45 d。选择glt A、fts Z、rib C引物对分离到的疑似菌落进行PCR并测序,所测核酸序列进行同源性比较及系统发育分析,确定巴尔通体种。利用间接免疫荧光法检测血清样本汉赛巴尔通体抗体水平。利用SPSS 13.0软件分析实验室数据与现场采集的流行病学数据。结果北京市猫的巴尔通体血培养分离率为13.8%,获得的22株分离株全部为汉赛巴尔通体。血清抗体阳性率为39.4%。流浪猫(30.4%)、染蚤猫(36.6%)、幼猫(27.9%)的血培养阳性率较高,差异有统计学意义。染蚤猫的血清抗体阳性率(61.0%)也显著高于未染蚤猫(31.9%)。结论北京市宠物猫和流浪猫中巴尔通体感染率较高,且均为对人致病的汉赛巴尔通体,需做好宠物猫的防蚤除蚤、流浪猫的管理来预防人类巴尔通体感染。

ObjectiveTo investigate the status of infection with Bartonella in domestic and feral cats in Beijing, China.MethodsEDTA- anticoagulated blood and serum samples were collected from cats, and the relevant epidemiological information was recorded. The anticoagulated blood was diluted 1∶4 in sterilized tryptic soy broth and a 100 μl aliquot was inoculated onto the brain-heart infusion agar supplemented with 5% defibrinated sheep blood followed by culturing in a 5% CO2incubator at 37 ℃ for 45 days. Bartonella-like isolates from the culture were examined by PCR analysis using the primers for glt A, fts Z, and rib C. The PCR products were sequenced, and homologous comparison and phylogenetic analysis were performed to identify the species of Bartonella. Indirect immunofluorescence assay was carried out to measure the titer of anti-Bartonella henselae IIFT（Ig G） in the serum samples. Data obtained from the experiments and the epidemiological information collected in the field were analyzed by the SPSS 13.0 software.ResultsThe positive rate for Bartonella culture isolates was 13.8% in the cats tested in Beijing, and all the 22 strains obtained were B. henselae. The seropositivity rate for anti-B. henselae Ig G was 39.4%. The feral cats, flea-infested cats, and kittens had significantly higher positive ratesfor Bartonella isolates（30.4%, 36.6%, and 27.9%, respectively）. The seropositivity rate for anti-B. henselae Ig G in flea-infested cats（61.0%） was also significantly higher than that in uninfested cats（31.9%）.Conclusion Bartonella infection is common in both domestic and feral cats in Beijing, and the species is identified to be human pathogen B. henselae.B artonella infection in humans could be avoided by flea control and preventing flea infestation in domestic cats, and strengthening the control of feral cats.