The genotypes of 78 strains of Helicobacter pylori from Calcutta, India (55 from ulcer patients and 23 from more-benign infections), were studied, with a focus on putative virulence genes and neutral DNA markers that were likely to be phylogenetically informative. PCR tests indicated that 80 to 90% of Calcutta strains carried the cag pathogenicity island (PAI) and potentially toxigenic vacAs1 alleles of the vacuolating cytotoxin gene (vacA), independent of disease status. This was higher than in the West (where cag PAI ؉ vacAs1 genotypes are disease associated) but lower than in east Asia. The iceA2 gene was weakly disease associated in Calcutta, whereas in the West the alternative but unrelated iceA1 gene at the same locus is weakly disease associated. DNA sequence motifs of vacAm1 (middle region) alleles formed a cluster that was distinct from those of east Asia and the West, whereas the cagA sequences of Calcutta and Western strains were closely related. An internal deletion found in 20% of Calcutta iceA1 genes was not seen in any of ϳ200 strains studied from other geographic regions and thus seemed to be unique to this H. pylori population. Two mobile DNAs that were rare in east Asian strains were also common in Calcutta. About 90% of Calcutta strains were metronidazole resistant. These findings support the idea that H. pylori gene pools differ regionally and emphasize the potential importance of studies of Indian and other non-Western H. pylori populations in developing a global understanding of this gastric pathogen and associated disease.
We compared putative molecular markers of virulence (vacA, cagA, and iceA) of Helicobacter pylori strains isolated from 52 adult duodenal ulcer patients from West Bengal, India, with those of H. pylori strains isolated from 48 adult healthy volunteers from the same region. On the basis of genotyping by PCR, we conclude that the H. pylori strains isolated from the two study groups were indistinguishable and that there are geographic variations in the association of certain putative H. pylori virulence genes with clinical status.
Objective: The aim of the present study was to characterize the predominant hepatitis B virus (HBV) strains and their molecular variants present in the HBV isolates of the different genotypes found among the chronic carriers of the virus in our community. Methods: Precore/core and core promoter regions of HBV DNA were amplified by polymerase chain reaction and then subjected to direct sequencing. Of the 64 hepatitis B surface antigen (HBsAg)-positive chronic HBV carriers investigated, 44 were HBeAg negative and 20 were HBeAg positive. Results: In addition to genotype D, which was the predominant genotype, 12 genotype C (18.7%) and 6 genotype A (9.4%) were also detected. Presence of T at nt 1858 has often been related to the development of precore stop mutation at nt 1896, while that of C has been related to the development of 1762–1764 double mutation. In our study group, 39 of the 44 HBeAg-negative samples have T1858. The precore stop codon mutation was found in only 8 (18%) of the HBeAg-negative samples. More than half of the HBeAg-negative samples had wild-type sequence in the precore region. The core promoter region could be sequenced from 40 samples, and 1762–1764 double mutation was detected in 13 (32.5%) of them. No significant changes could be detected in the core amino acid sequence of these isolates. Conclusion: The pattern of core promoter and precore mutation of HBV isolates in the present study is atypical and not in accordance with reports from other parts of the world, where genotype D and genotype C with T at codon 1858 are common.
Ovotesticular disorder of sexual differentiation (OTDSD) is a rare cause of disorder of sexual differentiation predominantly having 46,XX karyotype, female phenotype and ambiguous genitalia. We report a 15-year-old having male body habitus, axillary and pubic hair, well-developed penis and right-descended testis with history of penoscrotal hypospadias correction, presenting with three episodes of cyclical haematuria, who biochemically had normal serum testosterone (338 ng dl(-1) ) which increased following hCG stimulation (614 ng dl(-1) ), elevated estradiol (17.35 pg ml(-1) ) along with elevated luteinising hormone (11.3 mIU l(-1) ) and follicle-stimulating hormone (31 mIU l(-1) ). Ultrasonography followed by micturating cystourethrogram and cystoscopy confirmed the presence of prostate, uterus, cervix and vagina draining into the urogenital sinus continuing till the penile urethra and left intra-abdominal gonad. Patient underwent hysterectomy and left gonadectomy. Histopathologic study of resected gonad confirmed presence of ovotestis. Low estradiol (1.2 pg ml(-1) ) following gonadectomy confirmed the ovotestis origin of estradiol. Chromosomal analysis revealed complex karyotype predominant being 47,XYY (50%) followed by 46,XY (26%) and 45,X (24%). This is perhaps the first report of 47,XYY/46,XY/45,X causing OTDSD in a phenotypic male.
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