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Molecular analysis of Giardia duodenalis isolates from symptomatic and asymptomatic children from La Habana, Cuba

Author:
Jerez Puebla, Luis Enrique, Núñez, Fidel A., Santos, Lissette Pérez, Rivero, Lázara Rojas, Silva, Isabel Martínez, Valdés, Lucía Ayllón, Millán, Iraís Atencio, Müller, Norbert
Source:
Parasite epidemiology and control 2017 v.2 no.3 pp. 105-113
ISSN:
2405-6731
Subject:
DNA, Giardia lamblia, children, diarrhea, epidemiology, feces, genes, genetic markers, genetic variation, genotyping, giardiasis, hospitals, humans, mixed infection, parasites, phylogeny, polymerase chain reaction, ribosomal RNA, sequence analysis, triose-phosphate isomerase, Cuba
Abstract:
Giardiasis is considered the most common intestinal parasitic disease in humans worldwide. In Cuba, this infection has particularly a strong clinical impact on the child population. Giardia duodenalis is a highly diverse protozoan, which comprises a complex of eight morphologically identical genetic assemblages, further divided into sub-assemblages. The present study used triose phosphate isomerase (tpi) and small-subunit ribosomal RNA (SSU rRNA) genes as genetic markers for the identification of G. duodenalis assemblages and sub-assemblages in correlation with clinical and epidemiological data in children attended at the Paediatric Hospital “William Soler” and at Pedro Kouri Institute, between 2015 and 2016. A prevalence of 8% of G. duodenalis infection was recorded in stool samples after concentration techniques from 68 children out of 847 analysed. A 100% detection of Giardia DNA was achieved by a SSU-rRNA PCR, whereas DNA from 63 of 68 (92.6%) was successfully amplified by tpi-PCR. By this assemblage-specific tpi-PCR 32 (50.8%) assemblage B, 17 (27.0%) assemblage A and 14 (22.2%) mixed infection (A+B) were identified. Assemblage B was significantly (P<0.02) more frequently found in children with diarrhoea. Sequence analysis of the tpi gene of Giardia isolates from symptomatic children showed that assemblage A belonged to the sub-assemblage AII, and 4 sub assemblages BIV and 1 sub assemblage BIII were also recorded. Only 2 discordant genotyping results were observed by phylogenetic comparison of SSU-rRNA and tpi sequences. Further studies with novel molecular tools for a better discrimination at the sub-assemblage level are needed to identify the dynamics of spread of giardiasis and to verify possible correlations between Giardia genetic diversity and clinical manifestation.
Agid:
5731022