Prevalence and Molecular Characterization of Cryptosporidium species in Goats in Khartoum State and Pathogenicity of Cryptosporidium parvum in Goat Kids

Abstract

Cryptosporidium is a cosmopolitan zoonotic protozoan parasite recognized to infect animals and humans resulting in severe illness particularly in children and animal neonates. The aim of this research was to investigate the prevalence of spontaneous cryptosporidiosis in goats in Khartoum State along with molecular characterization of the isolates obtained and to study the pathogenicity of Cryptosporidium parvum human isolate in experimental goats. A total of 197 rectal faecal samples were randomly collected from goats in Omdurman (No=125) and East Nile (No=72) localities, and classified according to their consistency as diarrhoeic or non-diarrhoeic The animals were classified into three age groups; less than 6 months, 6 - 12 months and more than 12 months. All faecal samples were screened for the presence of Cryptosporidium spp. oocysts microscopically using formol-Ether concentration technique followed by modified Ziehl-Neelsen staining method, and immunologically via detection of Cryptosporidium copro-antigen using Enzyme Linked Immunosorbant Assay (ELISA). The results showed that the overall prevalence of Cryptosporidium in all goats was 20.8 % by faecal smears examination and 29.4% by ELISA. Infection was distributed among goats regardless of faeces consistency, age, sex, or the locality. Evaluation of results revealed that 10.9 % of microscopic negative samples were positive by ELISA, while all samples positive by microscopic examination were also positive by ELISA. Thus, microscopic examination of smears has (70.7 %) sensitivity and (100%) specificity compared with ELISA and the level between the two tests was very high. For the experimental study 12 male goat kids, 4-5 months old, were used. Eight kids were each infected with 102 oocysts of Cryptosporidium parvum isolated from immunocompremised patients, and four kids were kept as uninfected