背景:肠道寄生虫感染仍然是全球主要的公共卫生问题。隐孢子虫。,环孢菌属。和贾第虫.是在发达国家和发展中国家的普通人群中引起腹泻的寄生虫。加纳缺乏有关这些寄生虫的物种形成以及动物作为疾病传播媒介的作用的分子遗传研究的信息。因此,这项研究调查了这些引起人类腹泻的寄生虫,加纳的家鼠和野生动物使用分子工具。
方法:从生活在ShaiHills资源保护区(旅游景点)周围的9-12岁无症状的学童中收集粪便样本,来自野生动物(斑马,Kobs,狒狒,鸵鸟,布什老鼠和布什雄鹿)在同一地点,从鼹鼠国家公园(旅游景点)的疣猪和麦地那市场(阿克拉的一个受欢迎的蔬菜市场,加纳。隐孢子虫的18SrRNA基因(18SrRNA)和60kDa糖蛋白基因(gp60)。,贾第虫的谷氨酸脱氢酶基因(gdh)。和环孢菌属的18SrDNA。通过PCR和Sanger测序对所有样品进行分析,作为物种形成和遗传多样性的标记。
结果:从人类和动物收集的粪便样本中鉴定出的寄生虫物种包括隐孢子虫。C.Muris,C.parvum,C.tyzzeri,C.meleagridis和C.andersoni;Cyclopora物种C.cayetanensis;和Gardia物种,G.Lamblia和G.muris.对于隐孢子虫,gp60基因的存在证实了parvum的发现(41%,35/85样本)和人形C.hominis(29%,27/85个样本)在动物样本中。在加纳首次在动物样本中发现了环孢菌。只有一个人类样本(5%,1/20),但大多数动物样本(58%,51/88)在测试的样品中具有所有三种寄生虫物种。
结论:根据这些寄生虫粪便样本测试结果,我们得出的结论是,动物和人类共有三个属的物种(隐孢子虫,环孢菌,贾第虫),寄生物种主要存在于动物中,也存在于人类样本中,反之亦然。在无症状的人类和动物物种中,肠寄生虫作为混合感染的存在表明它们是感染的宿主。这是首次报道加纳动物中存在C.cayetanensis和C.hominis的研究。我们的发现强调了使用高通量遗传工具对这些寄生虫进行详细描述的必要性,以进一步了解这些寄生虫以及它们在加纳引起的被忽视的热带疾病,这些信息很少。
BACKGROUND: Enteric parasitic infections remain a major public health problem globally. Cryptosporidium spp., Cyclospora spp. and Giardia spp. are parasites that cause diarrhea in the general populations of both developed and developing countries. Information from molecular genetic studies on the speciation of these parasites and on the role of animals as vectors in disease transmission is lacking in Ghana. This study therefore investigated these diarrhea-causing parasites in humans, domestic rats and wildlife animals in Ghana using molecular tools.
METHODS: Fecal samples were collected from asymptomatic school children aged 9-12 years living around the Shai Hills Resource Reserve (tourist site), from wildlife (zebras, kobs, baboons, ostriches, bush rats and bush bucks) at the same site, from warthogs at the Mole National Park (tourist site) and from rats at the Madina Market (a popular vegetable market in Accra, Ghana. The 18S rRNA gene (18S rRNA) and 60-kDa glycoprotein gene (gp60) for Cryptosporidium spp., the glutamate dehydrogenase gene (gdh) for Giardia spp. and the 18S rDNA for Cyclospora spp. were analyzed in all samples by PCR and Sanger sequencing as markers of speciation and genetic diversity.
RESULTS: The parasite species identified in the fecal samples collected from humans and animals included the Cryptosporidium species C. hominis, C. muris, C. parvum, C. tyzzeri, C. meleagridis and C. andersoni; the Cyclopora species C. cayetanensis; and the Gardia species, G. lamblia and G. muris. For Cryptosporidium, the presence of the gp60 gene confirmed the finding of C. parvum (41%, 35/85 samples) and C. hominis (29%, 27/85 samples) in animal samples. Cyclospora cayetanensis was found in animal samples for the first time in Ghana. Only one human sample (5%, 1/20) but the majority of animal samples (58%, 51/88) had all three parasite species in the samples tested.
CONCLUSIONS: Based on these results of fecal sample testing for parasites, we conclude that animals and human share species of the three genera (Cryptosporidium, Cyclospora, Giardia), with the parasitic species mostly found in animals also found in human samples, and vice-versa. The presence of enteric parasites as mixed infections in asymptomatic humans and animal species indicates that they are reservoirs of infections. This is the first study to report the presence of C. cayetanensis and C. hominis in animals from Ghana. Our findings highlight the need for a detailed description of these parasites using high-throughput genetic tools to further understand these parasites and the neglected tropical diseases they cause in Ghana where such information is scanty.