Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark.
Center for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark.
J Zoo Wildl Med. 2021 Jan;51(4):752-760. doi: 10.1638/2020-0020.
Pathogenic spp., and have been reported to infect and cause severe enteritis and enterotoxemia in African ( spp.) and Asian elephants (). However, little information exists on whether healthy elephants carry and possibly shed these gastrointestinal organisms. This study was conducted to investigate the prevalence of all three bacteria in feces from healthy elephants in European zoos. Bacterial identification was performed by selective culture on fecal samples and a polymerase chain reaction (PCR) amplification protocol, on the basis of primers targeting the A gene ( spp.), the gene (), and the gene () from deoxyribonucleic acid extracted from elephant feces. The PCR protocol was validated prior to initiation of the investigation. Fecal samples collected from 50 African and 86 Asian elephants originating from 30 European zoologic institutions were investigated. The PCR validation revealed detection limits ranging from 10 to 10 colony-forming units per gram of feces of each gene. Only (one type A and two type E) was detected in the initial sampling (2.2%, three Asian elephants), whereas no spp. or was detected. At a follow-up sampling from -positive animals and relatives, 2 mo after the initial sampling, three animals were culture positive for spp. . All positive samples were obtained with bacterial culture, whereas no PCR reactions were positive. Despite carrying these pathogens, all culture-positive animals were clinically healthy and did not develop signs of gastrointestinal disease during the study period. The findings indicate that prevalence of spp., , and in feces from healthy Asian and African elephants in Europe is very low.
已报道致病性 spp. 和 可感染并引起非洲象（ spp.）和亚洲象（）严重肠炎和肠毒血症。然而，关于健康大象是否携带并可能排出这些胃肠道病原体的信息很少。本研究旨在调查欧洲动物园中健康大象粪便中这三种细菌的流行情况。通过对粪便样本进行选择性培养和聚合酶链反应（PCR）扩增方案，根据针对 spp.的 A 基因、 的 基因和来自大象粪便的脱氧核糖核酸（DNA）的 基因设计的引物进行细菌鉴定。在开始调查之前，对 PCR 方案进行了验证。从 30 个欧洲动物园机构采集了 50 头非洲象和 86 头亚洲象的粪便样本进行调查。PCR 验证显示，每个基因的检测限范围为 10 至 10 个菌落形成单位/克粪便。在初始采样中仅检测到 （一种 A 型和两种 E 型）（2.2%，3 头亚洲象），而未检测到 spp.或 。在初始采样后 2 个月的后续采样中，来自 -阳性动物及其亲属的 3 只动物的 spp. 呈细菌培养阳性。所有阳性样本均通过细菌培养获得，而 PCR 反应均未呈阳性。尽管携带这些病原体，但所有培养阳性的动物均临床健康，在研究期间未出现胃肠道疾病的迹象。研究结果表明，欧洲健康亚洲象和非洲象粪便中 spp.、 和 的流行率非常低。
