Bufavirus genotype 3 in Turkish children with severe diarrhoea.

Recently a parvovirus called bufavirus (BuV) has been implicated as a causative agent of diarrhoea. To further reveal the epidemiology and genetic characteristics of BuV, this study was performed in Turkish children with diarrhoea. BuV was detected in 1.4% (8/583) of stool samples. All stool samples from healthy children (n = 148) were negative for BuV. Diarrhoea in BuV-positive patients was severe and occurred mainly during the colder months of the year. Complete genome sequences were generated from four BuVs. Only BuV3 was found, which was genetically and phylogenetically similar to Bhutanese BuV3, indicating that BuV3 is prevalent in Asian countries.

The role of human herpesvirus 6, human herpesvirus 7, Epstein-Barr virus and cytomegalovirus in the aetiology of pityriasis rosea.

AIM: To identify the role of human herpesvirus 6 (HHV-6), HHV-7, Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in the pathogenesis of pityriasis rosea (PR). MATERIAL: Polymerase chain reaction with specific primers for HHV-6 and HHV-7 DNA sequences was performed on the blood and tissue samples of 25 patients with PR and on the blood samples of age- and sex-matched healthy controls. HHV-6, EBV, CMV immunoglobulin M (IgM) and IgG were analysed by enzyme-linked immunosorbent assay, HHV-7 IgM and IgG were analysed by indirect immunofluorescence on the serum samples of the study population. In the patient group, the values were studied 2 weeks later again (second control). RESULTS: There were no differences between the first and second controls of the patients and healthy subjects regarding HHV-6 IgM, HHV-7 IgM, CMV IgM, EBV IgM results. There were significant differences between the first [HHV-6 DNA (2 of 25), HHV-7 DNA (6 of 25)] and second control [HHV-6 DNA (1 of 25), HHV-7 DNA (11 of 25)] of the patients for the blood samples in favour of HHV-7. PR patients showed higher amounts of HHV-6 and HHV-7 DNA positivity when compared with that of healthy subjects. HHV-7 seemed to be more important regarding tissue samples [HHV-6 DNA (7 of 25), HHV-7 DNA (12 of 25) first control, HHV-6 DNA (6 of 25), HHV-7 DNA (12 of 25) second control] as well as blood samples. CONCLUSION: Though our results failed to support a causal relationship among EBV, CMV and PR, they indicated a possible role for HHV-6 and especially HHV-7 in a group of Turkish patients but other aetiological factors may exist.

Assessment of human papilloma viral load of archival cervical intraepithelial neoplasia by real-time polymerase chain reaction in a Turkish population.

The purpose of this study was to determine the existence, and viral load of human papilloma virus (HPV) subtypes 16 and 18 in paraffinized cervical intraepithelial neoplasia (CIN) samples by real-time polymerase chain reaction (RT-PCR). Overall 94 women were included. Of these patients 47 (50%) had CIN I, 27 (28.8%) had CIN II, and 20 (21.2%) had CIN III. HPV positivity for these three groups were 4.2%, 14.8% and 45%, respectively. HPV positivity in CIN III patients was significantly higher than CIN I (OR = 18.41, 95% CI 3.00-145.73; p < 0.001), and CIN II patients (OR = 4.70, 95% CI 1.00-23.76; p = 0.05). The difference between CIN I and II was not significant (p = 0.18). Viral loads were 10(2), and 10(4) copy/ml for two CIN I patients; 10(2), 10(3), and 10(5) for three CIN II patients; and 10(2), 10(3), 10(4), 10(4), 10(5), 10(5), and 10(6) copy/ml for eight patients with CIN III. Viral load of the remaining one patient could not be assessed. No significant variance was noted among the groups with respect to viral load (p = 0.73). RT-PCR had important advantages of detecting, typing, and quantifying at the same time. Although HPV positivity was increased significantly by the degree of lesions, this relation was not observed for viral load.

Distribution of secreted aspartyl proteinases using a polymerase chain reaction assay with SAP specific primers in Candida albicans isolates.

Secreted aspartyl proteinase (Sap) distribution among different C. albicans isolates was determined using SAP-specific primers in polymerase chain reaction (PCR) assay. SAP1, SAP2, and SAP3 were detected in 13 of 40 (32.5%), SAP4 in 38/40 (95%), SAP5 were detected in 30/40 (75%), SAP6 in 23/40 (57.5%) of C. albicans strains isolated from blood cultures. SAP1-SAP3 were detected in 37 of 40 (92.5%), SAP4 were detected in 3/40 (7.5%), SAP5 in 3/40 (7.5%), SAP6 in 5/40 (12.5%) of C. albicans strains isolated from vaginal swab cultures. Sap1, Sap2 and Sap3 isoenzymes were found to be related to the vaginopathic potential of C. albicans; Sap4, Sap5 and Sap6 isoenzymes were found to be correlated with systemic infections.

Molecular epidemiology of hepatitis B, C and D viruses in Turkish patients.

Different genotypes of the hepatitis viruses may influence the clinical outcome of the disease. The distribution of genotypes may vary according to geographical regions. The aim of this study was to evaluate hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV) genotypes in Turkish patients with chronic hepatitis in a large cohort of patients. Genotyping was performed in 41, 59 and 365 patients with chronic hepatitis B, D and C, respectively, and 36 hemodialysis patients with chronic hepatitis C. Genotypes were determined by direct sequencing in hepatitis B and by polymerase chain reaction-restriction fragment length polymorphism in hepatitis C and D patients. In addition, HBV subtyping by multiplex PCR and subtype specific ELISA were performed in 83 and 71 HBsAg (+) blood donors, respectively. All hepatitis B (100%) and hepatitis D (100%) patients had genotype D and type I, respectively. HBsAg subtyping by two methods yielded that 99% of the patients were subtype ayw. S gene amino acid sequence in the 41 patients included for HBV genotyping revealed the ayw2 subtype. Genotype distribution of 365 patients with chronic C hepatitis were as follows: 306 (84%) patients genotype 1b, 43 (11%) patients genotype 1a, 10 (3%) patients genotype 2, 3 (1%) patients genotype 3, 3 (1%) patients genotype 4. Among 36 patients receiving hemodialysis, 28 (78%) patients had genotype 1b and 8 (22%) patients had genotype 1a. The study indicates that Turkish patients with chronic viral hepatitis show very little genotypic heterogeneity. Subtype ayw and the genotype D of HBV DNA, and the type I of HDV RNA represent almost 100% of related infections. The genotype 1b of HCV RNA was found to be significantly dominant in Turkish patients.

YSDD: a novel mutation in HBV DNA polymerase confers clinical resistance to lamivudine.

The emergence of drug-resistant virus in hepatitis B virus (HBV) patients treated with lamivudine is well documented. In this study, we determined the mutations occurring in the tyrosine-methionine-aspartate-aspartate (YMDD) amino acid motif of the HBV DNA polymerase gene, as well as upstream and downstream of this region, in patients with breakthrough virus during lamivudine therapy. Thirty-one Turkish patients (20 patients HBeAg positive, 11 patients HBeAg negative and anti-HBe positive) with chronic HBV infection who completed at least 104 weeks of lamivudine treatment were investigated. All patients received lamivudine, (150 mg/day), for 104 weeks, with or without 4 months of interferon (IFN) combination. HBV-specific sequences were amplified by polymerase chain reaction (PCR) from sera of patients with breakthrough virus, and the PCR products were directly analysed by sequencing. Breakthrough virus was detected in seven of the 31 patients (22.6%) between 9 and 18 months of therapy. Of the seven patients, six were HBeAg positive at baseline, and four had a double mutation consisting of rtM204V and rtL180M, while two had an rtM204I change. In one patient, two base substitutions at rt204 (ATG --> AGT; T to G and G to T) lead to a methionine to serine change (YMDD --> YSDD). This novel DNA pol mutation was detected at month 18 of lamivudine treatment. In addition, this new variant had the rtL180M mutation and a 12 base pair deletion in the pre-S1 region between nucleotides 43-54. The YSDD mutation was still present 6 months after lamivudine discontinuation. In vitro transfection studies also confirmed that the YSDD strain is resistant to lamivudine. In conclusion, the results indicate that, in addition to a Met --> Val and Met --> Ile change in YMDD, a Met --> Ser change at rt204 (YMDD --> YSDD) associated with the rtL180M change can also emerge during lamivudine treatment, which confers lamivudine resistance in vivo and in vitro, leading to virological breakthrough and ALT increases.