Molecular Characterization and Risk Factors of Giardia duodenalis among School Children from La Habana, Cuba

Giardia duodenalis is considered the most common protozoan infecting humans worldwide. Molecular characterization of G. duodenalis isolates has revealed the existence of eight groups (assemblages A to H) which differ in their host distribution. A cross-sectional study was conducted in 639 children from La Habana between January and December 2013. Two assemblage-specific PCRs were carried out for the molecular characterization. The overall prevalence of Giardia infection was 11.9%. DNA from 63 of 76 (82.9%) samples was successfully amplified by PCR-tpi, while 58 from 76 (76.3%) were detected by PCRE1-HF. Similar results by both PCRs were obtained in 54 from 76 samples (71%). According to these analyses, assemblage B and mixed assemblages A + B account for most of the Giardia infections in the cohort of children tested. Our current study identified assemblage B as predominant genotype in children infected with Giardia. Univariate analysis indicated that omission of washing hands before eating and keeping dogs at home were significant risk factors for a Giardia infection. In the future, novel molecular tools for a better discrimination of assemblages at the subassemblages level are needed to verify possible correlations between Giardia genotypes and symptomatology of giardiasis

Alteraciones renales en la drepanocitosis Renal disorders in sickle cell disease

La drepanocitosis está asociada con un amplio espectro de alteraciones renales que tienen su base en la falciformación de los eritrocitos en los vasos de la médula renal, que conduce a fenómenos de isquemia, microinfartos y anomalías de la función tubular. Se producen también alteraciones glomerulares funcionales reversibles de la autorregulación renal (hiperfiltración), que pueden conducir a cambios anatómicos irreversibles con glomeruloesclerosis segmentaria focal. Estas anomalías se expresan tempranamente como microalbuminuria, proteinuria y de forma mas tardía, como síndrome nefrótico e insuficiencia renal crónica. Medidas terapéuticas como el uso de inhibidores de la enzima convertidora de la angiotensina II, de los bloqueadores del receptor de la angiotensina II, asociados o no con la hidroxiurea, pueden prevenir o retardar el daño glomerular. En el presente trabajo se exponen de forma resumida aspectos relacionados con la fisiopatología del daño renal en la drepanocitosis y su tratamiento.<br>Sickle cell disease is associated with a wide range of renal disorders resulting from the falciformation of erythrocytes in vessels of the renal medulla, leading to ischemia, microinfarctions and tubular function abnormalities. Reversible glomerular functional renal self-regulation disorders (hyperfiltration) also occur, which may lead to irreversible anatomical changes with focal segmental glomerular sclerosis. These anomalies are expressed at an early stage as microalbuminuria and proteinuria, and at a later stage as nephrotic syndrome and chronic renal failure. Therapeutic measures such as the use of angiotensin-II converting enzyme inhibitors and angiotensin-II receptor blockers, associated or not with hydroxyurea, may either prevent or delay glomerular damage. The paper succinctly presents the physiopathology of renal damage in drepanocytosis and its treatment

Diagnosis of intestinal protozoan infections in patients in Cuba by microscopy and molecular methods: advantages and disadvantages

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Concordance of Giardia duodenalis assemblages determined by different PCR methodologies in three observational studies in Cuba

Giardia duodenalis is one of the most important intestinal parasites globally, especially in children, and in Cuba is the leading cause of chronic paediatric diarrhoea in this population. G. duodenalis is composed of eight genetic groups (or assemblages), two of which (A and B) are apparently zoonotic, occurring in both humans and other animals. However, consensus on the most appropriate genotyping scheme for optimal characterization of G. duodenalis isolates is lacking. In this article we present the results of three descriptive observational studies conducted in Havana, Cuba between 2010 and 2013, with the aim of comparing the results from molecular (PCR) approaches targeting different genes in order to assign with confidence 224 isolates of G. duodenalis to the correct assemblages. In each sub-study, following DNA isolation by the phenol/chloroform/isoamyl alcohol extraction method, PCR targeting the triose phosphate isomerase (tpi) gene was used for molecular characterization, as well as one additional PCR-method targeting another gene or pair of genes. DNA amplification was obtained in 87%, 83%, and 80% in the three sub-studies. Although excellent agreement (kappa index = 1) was recorded between results from some pairs of genes, for other combinations only moderate or substantial agreement was achieved. These results highlight the importance of interpretation of genotyping data, especially when single genetic markers are used. From the results of our studies, PCR targeting a combination of the tpi gene and the intergenic spacer region of rDNA may be a useful approach for the molecular characterization of G. duodenalis isolates

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

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. 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 () and small-subunit ribosomal RNA (SSU rRNA) genes as genetic markers for the identification of 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 infection was recorded in stool samples after concentration techniques from 68 children out of 847 analysed. A 100% detection of DNA was achieved by a SSU-rRNA PCR, whereas DNA from 63 of 68 (92.6%) was successfully amplified by -PCR. By this assemblage-specific -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 ( < 0.02) more frequently found in children with diarrhoea. Sequence analysis of the gene of 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 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 genetic diversity and clinical manifestation

Diagnosis of intestinal protozoan infections in patients in Cuba by microscopy and molecular methods: advantages and disadvantages

publishedVersio

Molecular Characterization and Risk Factors of Giardia duodenalis among School Children from La Habana, Cuba

Giardia duodenalis is considered the most common protozoan infecting humans worldwide. Molecular characterization of G. duodenalis isolates has revealed the existence of eight groups (assemblages A to H) which differ in their host distribution. A crosssectional study was conducted in 639 children from La Habana between January and December 2013. Two assemblage-specific PCRs were carried out for the molecular characterization. The overall prevalence of Giardia infection was 11.9%. DNA from 63 of 76 (82.9%) samples was successfully amplified by PCR-tpi, while 58 from 76 (76.3%) were detected by PCRE1-HF. Similar results by both PCRs were obtained in 54 from 76 samples (71%). According to these analyses, assemblage B and mixed assemblages A + B account for most of the Giardia infections in the cohort of children tested. Our current study identified assemblage B as predominant genotype in children infected with Giardia. Univariate analysis indicated that omission of washing hands before eating and keeping dogs at home were significant risk factors for a Giardia infection. In the future, novel molecular tools for a better discrimination of assemblages at the subassemblages level are needed to verify possible correlations between Giardia genotypes and symptomatology of giardiasis