Genetic characterization of Giardia lamblia isolates from Egyptian patients with relation to clinical giardiasis.

Investigators tried to correlate clinical presentation of giardiasis to the different genotypes, but controversial data were described through the last decade. The clinical manifestations of 89 Giardia patients were classified into:- GI: 52 symptomatic patients and GII: 37 asymptomatic patients. Genetic characterization of G. lamblia of the patients' fecal samples was performed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) technique b using triose phosphate isomerase gene (tpi). Forty-two patients had genotype A1 (47.19%), 16 had genotype A2 (17.98%), 10 had genotype B (11.23%) and 19 had mixed genotype infection (21.35%). However, PCR-RFLP failed to determine Giardia genotype of only two cases (2.25%). The 20 control fecal samples obtained from healthy subjects showed negative results for G. lamblia by PCR-RFLP method. Of 52 cases in GI, the prevalence genotype A1 was 44.23%, genotype A2 was 19.23%, genotype B was 13.46%, mixed genotype infection was 21.15% and undetermined genotype was 1.92% as compared to 51.35%, 16.21%, 8.11%, 21.62% and 2.70% in GII, respecttively. There was no significant difference between both groups as regard the different Giardia genotypes (p>0.05). Statistical analysis of each symptom in different genotypes revealed insignificant (p>0.05). The results denied any correlation between G. lamblia genotype and the clinical presentation of giardiasis.