Molecular Characterisation of Cryptosporidium Species among Patients Presenting with Diarrhoea in Some Parts of Kaduna State, Nigeria

Abstract

Cryptosporidium species have been widely reported to be responsible for significant diarrhoea in humans and animals. However, little information is available on the prevalence and molecular characterisation of Cryptosporidium among humans in Kaduna State. This study examined the distribution, genotypes and subgenotypes of Cryptosporidium implicated in cryptosporidiosis in some parts of Kaduna State, Nigeria. A total of 30 Cryptosporidium positive samples were collected and analysed. The samples were genotyped by nested PCR followed by restriction fragment length polymorphism using restriction enzymes RsaI, SspI and VspI. The samples were further subgenotyped by nested PCR and amplification of gp60 kDa gene and subsequent nucleotide sequencing. PCR-RFLP analysis of the 18S rRNA gene fragment revealed that 54.5% (12/22) and 45.5% (10/22) of the Cryptosporidium were Cryptosporidium parvum and Cryptosporidium hominis respectively. Nucleotide sequence analysis of the gp60 kDa gene yielded 3 subtype families, namely IIa (58.3%), IIc (8.3%) and IId (33.3%), among the Cryptosporidium parvum obtained from the human samples. Three subtype families were also identified in Cryptosporidium hominis [Ia (50.0%), Id (40.0%) and Ie (10.0%)]. The zoonotic subgenotype IIaA15G2R1 (85.7%) predominated over the IIaA16G2R1 (14.3%) subgenotype. One anthroponotic Cryptosporidium parvum subgenotype (IIcA5G3a) was detected in humans. The Cryptosporidium hominis subgenotypes included IaA14R6 (60.0%), IaA15R3 (40.0%), IdA10G2 (75.0%), IdA10 (25.0%) and IeA11G3T3 (100.0%). This study showed that cryptosporidiosis is prevalent in the study population. The similarity of prevalence of Cryptosporidium parvum (54.5%) and Cryptosporidium hominis (45.5%) indicates that anthroponotic transmission is as important as zoonotic transmission of cryptosporidiosis in the study population.