Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Vet Parasitol. 2011 Jun 10;178(3-4):241-5. doi: 10.1016/j.vetpar.2010.12.048. Epub 2011 Jan 11.
Despite numerous molecular epidemiologic studies of cryptosporidiosis in dairy cattle in industrialized countries, there are very few studies on the diversity and public health significance of Cryptosporidium species in native cattle in developing countries. In this study, a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the small-subunit (SSU) rRNA gene was used to detect and identify Cryptosporidium spp. in 194 fecal specimens from 2 to 365 days old calves in 20 White Fulani and Sokoto Gudali herds in Nigeria. Thirty one (16.0%) of the specimens were positive for Cryptosporidium. Restriction digestion of the PCR products showed the presence of Cryptosporidium bovis (7.2%), Cryptosporidium ryanae (4.1%), Cryptosporidium andersoni (2.5%), and concurrent occurrence of C. bovis and C. ryanae (1.5%), and C. bovis and C. andersoni (0.5%). There were no significant differences (p>0.05) in Cryptosporidium infection rates by sex, herd location, management system, breed of calves, or fecal consistency. However, calves 180 days or younger had a higher infection rate of Cryptosporidium than older calves (p=0.034). Likewise, younger calves also had higher occurrence of C. bovis and C. ryanae (p=0.022). The absence of zoonotic Cryptosporidium parvum in the calves studied suggests that native breeds of cattle may not be important in the transmission of human cryptosporidiosis in Kaduna State, Nigeria.
尽管在工业化国家对奶牛中的隐孢子虫病进行了大量的分子流行病学研究，但对发展中国家本地牛中隐孢子虫种的多样性和公共卫生意义的研究却很少。在这项研究中，使用聚合酶链反应（PCR）-限制性片段长度多态性（RFLP）分析小亚基（SSU）rRNA 基因来检测和鉴定来自尼日利亚 20 个白富拉尼和 Sokoto Gudali 牛群的 194 份 2 至 365 天大的犊牛粪便标本中的隐孢子虫。31 份（16.0％）标本为隐孢子虫阳性。PCR 产物的限制性消化显示存在牛隐孢子虫（7.2％），Ryanae 隐孢子虫（4.1％），Anderson 隐孢子虫（2.5％），并且同时存在牛隐孢子虫和 Ryanae 隐孢子虫（1.5％），以及牛隐孢子虫和 Anderson 隐孢子虫（0.5％）。隐孢子虫感染率在性别，畜群位置，管理系统，犊牛品种或粪便稠度方面无显着差异（p>0.05）。但是，180 天或更年轻的犊牛的隐孢子虫感染率高于年龄较大的犊牛（p=0.034）。同样，年幼的犊牛也有更高的牛隐孢子虫和 Ryanae 隐孢子虫发生（p=0.022）。在所研究的犊牛中未发现致人类隐孢子虫病的小隐孢子虫，这表明尼日利亚卡杜纳州的本地牛种可能在人类隐孢子虫病的传播中并不重要。
