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Detection of Helicobacter pylori ‐Specific Genes in the Oral Yeast
Author(s) -
Siavoshi Farideh,
Salmanian Ali Hatef,
Kbari Fereshteh Akbari,
Malekzadeh Reza,
Massarrat Sadegh
Publication year - 2005
Publication title -
helicobacter
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.206
H-Index - 79
eISSN - 1523-5378
pISSN - 1083-4389
DOI - 10.1111/j.1523-5378.2005.00319.x
Subject(s) - caga , biology , helicobacter pylori , microbiology and biotechnology , yeast , polymerase chain reaction , gene , 16s ribosomal rna , ribosomal rna , genetics , virulence
Backgrounds. Until today, human stomach is the only recognized habitat of Helicobacter pylori . However, recruitment of DNA‐based methods has made possible the detection of H. pylori in water and oral cavity, thus suggesting fecal–oral and oral–oral routes for transmission of H. pylori , respectively. In this study, yeast has been proposed as a common vector for transmission of H. pylori . Thus designed primers were recruited to target 16S rDNA and cagA genes in the oral yeasts by PCR. Materials and methods. Eighteen yeasts were examined microscopically for the presence of bacterial‐like bodies . DNAs were extracted from oral yeasts using phenol–chloroform method. Amplification conditions were optimized as 33 cycles and annealing temperatures of 63 °C for 16S rDNA and 51 °C and 52 °C for cagA gene which was targeted in two steps. DNAs of H. pylori and Saccharomyces cerevisiae were used as controls. Polymerase chain reaction (PCR) products of two genes from one yeast and from H. pylori were cloned in pCAP and subsequently subcloned in pSK+ and were sequenced. Results. Bacterial‐like bodies were observed in all oral yeasts. The amplified products of 16S rDNA from all oral yeasts were homologous in size with those of H. pylori . Fifteen out of eighteen (83%) yeasts contained cagA gene, homologous to H. pylori . CagA was not amplified from three yeasts and S. cerevisiae . Analysis of the sequenced products of 16S rDNA and cagA from one oral yeast showed 98% homology with those of H. pylori . Conclusions. The presence of H. pylori inside the yeast was indicated by light microscopy and PCR. It appears that yeasts, which are abundant in nature and thrive the mucosal surfaces of human, might serve as reservoirs and vehicles of H. pylori .