Genotyping of human parvovirus B19 in clinical samples from Brazil and Paraguay using heteroduplex mobility assay, single-stranded conformation polymorphism and nucleotide sequencing.

Heteroduplex mobility assay, single-stranded conformation polymorphism and nucleotide sequencing were utilised to genotype human parvovirus B19 samples from Brazil and Paraguay. Ninety-seven serum samples were collected from individuals presenting with abortion or erythema infectiosum, arthropathies, severe anaemia and transient aplastic crisis; two additional skin samples were collected by biopsy. After the procedure, all clinical samples were classified as genotype 1.

Genotyping of human parvovirus B19 in clinical samples from Brazil and Paraguay using heteroduplex mobility assay, single-stranded conformation polymorphism and nucleotide sequencing

Heteroduplex mobility assay, single-stranded conformation polymorphism and nucleotide sequencing were utilised to genotype human parvovirus B19 samples from Brazil and Paraguay. Ninety-seven serum samples were collected from individuals presenting with abortion or erythema infectiosum, arthropathies, severe anaemia and transient aplastic crisis; two additional skin samples were collected by biopsy. After the procedure, all clinical samples were classified as genotype 1.

Heteroduplex mobility assay and single-stranded conformation polymorphism analysis as methodologies for detecting variants of human erythroviruses.

Variant samples from the three genotypes of erythroviruses have already been detected using sequencing as methodology for analysis. This study aimed to investigate the efficacy of single-stranded conformation polymorphism (SSCP) analysis and heteroduplex mobility assay (HMA) as methodologies to detect human erythrovirus variants, using their VP1 unique region sequences. Clinical samples and plasmids of PVBAUA, A6, LaLi, V9Gh3051, and D91.1 erythrovirus variants as prototypes of the three genotypes were used. SSCP analysis was able to distinguish all divergences among the plasmids, including the two mutation points between LaLi and A6 plasmids that led to distinct electrophoresis mobility patterns. Although HMA analysis was unabled to detect two mutation points between LaLi and A6, it enabled the differentiation among all other plasmids that revealed specific electrophoresis patterns, with high-enough sensibility to detect 1.5% nucleotide substitutions. When 57 clinical samples were analyzed, 33 of them presented an identical pattern to PVBAUA by HMA and SSCP analyses, two of them were sequenced and presented an identical sequence in relation to PVBAUA. Another pattern was found for 21 samples. Among these, two samples were sequenced, revealing one mutation point in relation to PVBAUA, while each one of the three remaining samples presented a distinct pattern, showing two or three mutations in relation to PVBAUA by sequencing. HMA and SSCP analyses were suggested as methodologies suited for detecting genetic mutations of human erythroviruses in developing countries because of their practicability and minor costs for reagents and equipment.

Detection of human parvovirus B19 infection: a study of 212 suspected cases in the state of Rio de Janeiro, Brazil.

BACKGROUND: Parvovirus B19 infections are associated with different clinical manifestations that vary from symptom-less to severe. The main clinical manifestations are erythema infectiosum or fifth disease, transient aplastic crisis in individuals with hemoglobinopathies, chronic anemia in the immunocompromised, acute polyarthralgia syndrome in adults, hydrops fetalis, spontaneous abortion and stillbirth. Although the classical features of B19 and rubella infections are distinct, uncommon presentations can lead to misdiagnosis. OBJECTIVE: The goal of this study was to assess the occurrence of parvovirus B19 (B19) infection in patients with clinical signs of toxoplasmosis or rubella, both of which were not confirmed by laboratorial techniques. STUDY DESIGN: Serum samples from 214 patients were collected between January 1996 and December 1997 in the state of Rio de Janeiro, Brazil, B19 specific IgG and IgM were detected by using commercial enzyme-linked immunosorbent assays (ELISA), and viral nucleic acid was detected employing a nested polymerase chain reaction (PCR) protocol. RESULTS: Combining the results obtained by IgM ELISA and PCR, 14.5% of the samples were positive in one or both tests, with a concordance of 92.5% between the two techniques. CONCLUSIONS: Specimens collected in 16 out of 22 municipalities were positive in at least one out of the three tests employed, indicating that parvovirus B19 circulates in several regions of the state of Rio de Janeiro.