Abstract:

Objective To understand the situation of Giardia lamblia infection in HIV-infected individuals and in kindergarden children in rural area of Anhui Province and analyze the genotype of the parasite. Methods HIV-infected individuals registered in an AIDS treatment facility and children in a local kindergarden were included in this study during April 24 and May 9, 2015. The feces were collected, stained by iodine solution, and examined by microscopy. DNA was extracted from the positive feces, and nested PCR was performed to amplify the triosephosphate isomerase（tpi） gene  of G. lamblia. The products were sequenced. The phylogenetic tree was constructed with BLAST, ClustalX 1.83 and MEGA6.0 softwares for analysis of homology and phylogeny. Results One hundred and twenty-seven HIV-infected individuals and 125 kindergarden children were included. G. lamblia infection was found in three children and one HIV-infected individual. The infection detection rate in children and HIV patients was 2.40% （3/125） and 0.79% （1/127）, respectively （P>0.05）. Feces of the three infected children was soft, and no symptoms of diarrhea and stomachache were complained. Feces of the HIV-infected individual was washy, and symptoms like diarrhea, stomachache, weakness and weight loss were reported. PCR produced a specific band at 500 bp for the four persons. The sequencing results further confirmed infection in these four persons. The duplicate samples of the infected HIV patient had a 79% sequence similarity, and were 79% and 98% homologous to the Shanghai human strain of G. lamblia（GenBank accession No: KF271445）, respectively. The samples of the 3 children had a 99% similarity, and all were 79% homologous to the Shanghai human strain of G. lamblia. The phylogenetic tree showed that the isolate from the HIV patient was mixed genotype of A+B, while those from the 3 children were all  assemblage A. There was a high similarity between the isolates. Conclusions There is Giardia infections in HIV patients and kindergarden children in the area. The genotype of the isolate from the HIV individual is mixed assemblage A+B while those from the children are assemblage A.

Key words: Children, HIV-infected individual, Giardia lamblia, Molecular characteristic