Abstracto

Genotyping of Giardia lamblia using semi-nested PCR technique and restriction fragment length polymorphism (RFLP) in Sohag Governorate, Egypt.

Amal Mostafa Ahmed, Hanaa Ahmed El-Hady, Hisham Ibrahim Osman, Noha Sammer Ahmed

Background: Giardia lamblia is a protozoan parasite, and it is most frequently detected as an intestinal pathogenic parasite in humans worldwide. Objective: To determine the genotype of Giardia lamblia and the sub-assemblages for each genotype using semi-nested PCR and restriction fragment length polymorphism. Methodology: DNA samples were isolated from the stools of 100 patients infected with G. lamblia (after examination by copromicroscopy) and amplified by PCR. The 93 positive samples after using PCR, were digested with NlaIV and RsaI fragment restriction fragment enzymes. The samples were taken randomly and the residence and age for every case were taken. According to the location of residence, the cases were divided into urban areas (the cities) and rural areas (the villages). Result: Genotype A represented (32.3%) {AI (5.3%), AII (26.9%)}, genotype B represented (39.8%) {BIII (22.5%), BIV (17.3%)} and mixed A, B represented (28%). Giardia genotype B was the most common genotype among cases included in this study while sub-genotype AII accounted for the majority of cases. Males were more affected 62 (66.66%) than females 31 (33.33%), (79.6%) cases were from rural areas while only (20.4%) cases were from urban; the highest incidence was between (2-6) years represented 72.1%. The variation in sex, residence and age distribution was found to be statistically significant (PV=0.05, 0.03, 0.03 respectively). Molecular analysis for glutamate dehydrogenase (gdh) gene had been shown to assemble genotypes A and B isolates into four groups: AI, AII, BIII, and BIV by using semi-nested PCR technique. Conclusion: Giardiasis is a still common parasitic infection, particularly in young children in rural areas more than urban areas, and in males more than in females in Sohag Governorate, Upper Egypt. Molecularly it was found that both genotype A (sub-genotypes AI, AII), genotype B (sub-genotypes BIIIm B IV), as well as mixed genotypes A and B, were found in examined patients.