World Journal of Microbiology and Biotechnology, 2014
Helicobacter pylori infection is common in Iran as in other developing countries. Certain genotyp... more Helicobacter pylori infection is common in Iran as in other developing countries. Certain genotypes of H. pylori have been associated with increased occurrence of chronic gastritis, peptic ulcers, and gastric adenocarcinoma. The aim of this study was to investigate the clinical relevance of cagL gene and other virulence genotypes of H. pylori isolates with clinical outcomes in Iranian patients. Totally, 126 symptomatic patients who underwent gastroduodenal endoscopy were enrolled in the study. Sixty-one H. pylori strains were isolated from the patients studied. The presence of the cagL, cagA, vacA, iceA, babA2 and sabA genes in the corresponding H. pylori isolates were determined by polymerase chain reaction and the results were compared with clinical outcomes and histopathology. The cagL, cagA, vacA s1, vacA s2, vacA m1, vacA m2, iceA1, iceA2, babA 2 , and sabA genotypes were detected in 96.7, 85.2, 75.4, 24.6, 29.5, 70.5, 42.6, 23, 96.7, and 83.6 % of the isolates, respectively. The three genotypic combinations, cagL/cagA/vacAs1m1/iceA1/babA2/sabA, cagL/cagA/vacAs1m2/iceA1/babA2/sabA, and cagL/cagA/ vacAs1m2/iceA2/babA2/sabA were determined as the most prevalent combined genotypes. There was a significant correlation between the presence of cagL gene and cagA positivity (P = 0.02). No significant correlation was found between the various genotypes and clinical outcomes (P [ 0.05). The present study showed a very high prevalence of cagL genotype among the H. pylori isolates from Iranian patients. Our results demonstrated that neither single genotype nor combination genotypes of virulenceassociated genes was significantly helpful markers for predicting the severity of gastroduodenal disease associated with H. pylori infection in Iranian patients.
Aminoglycosides are potent bactericidal agents that play an important role in antistapylococcal t... more Aminoglycosides are potent bactericidal agents that play an important role in antistapylococcal therapy. In this study, we used a multiplex polymerase chain reaction assay to investigate the prevalence of aac(6 0 )-Ie=aph(2@), ant(4 0 )-Ia, and aph(3 0 )-IIIa, the genes encoding the most clinically prevalent aminoglycoside-modifying enzymes, and simultaneous detection of the methicillin resistance gene, mecA, in Staphylococcus aureus isolates. A total of 100 S. aureus clinical isolates were collected and tested by disk diffusion and agar dilution method for susceptibility testing. All isolates were screened for the presence of the three aminoglycoside-modifying enzyme genes and the methicillin resistance gene. The ant(4 0 )-Ia was the most frequent gene (58%), and aac(6 0 )-Ie=aph(2@) and aph(3 0 )-IIIa genes were found in 46% and 6% of the isolates, respectively. All isolates harboring the aac(6 0 )-Ie=aph(2@) gene were resistant to gentamicin (100% concordance). Seventy-one percent of the isolates demonstrated resistance to at least one of the aminoglycosides tested. PCR results showed that 53% of all isolates harbored the mecA gene. Aminoglycoside resistance was closely associated with oxacillin resistance ( p < 0.05). In conclusion, because of the high rate of aminoglycoside resistance among S. aureus clinical isolates observed in this study, periodic surveillance on the resistance prevalence should be performed.
World Journal of Microbiology and Biotechnology, 2014
Phenotypic identification of non-pylori Helicobacter species has always been problematic and time... more Phenotypic identification of non-pylori Helicobacter species has always been problematic and timeconsuming in comparison with many other bacteria. We developed a rapid two-step identification assay based on PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the 23S rRNA gene for differentiating between non-pylori Helicobacter species. A new genusspecific primer pair based on all available complete and partial 23S rRNA sequences of Helicobacter species was designed. In silico restriction analysis of variable regions of the 23S rRNA gene suggested SmaI and HindIII endonucleases would provide a good level of differentiation. Analysis of the obtained 23S rRNA RFLP patterns divided all Helicobacter study strains into three species groups (groups A-C) and 12 unique restriction patterns. Wolinella succinogenes also gave a unique pattern. Our proposed PCR-RFLP method was found to be as a valuable tool for routine identification of non-pylori Helicobacter species from human or animal samples.
World Journal of Microbiology and Biotechnology, 2014
Helicobacter pylori infection is common in Iran as in other developing countries. Certain genotyp... more Helicobacter pylori infection is common in Iran as in other developing countries. Certain genotypes of H. pylori have been associated with increased occurrence of chronic gastritis, peptic ulcers, and gastric adenocarcinoma. The aim of this study was to investigate the clinical relevance of cagL gene and other virulence genotypes of H. pylori isolates with clinical outcomes in Iranian patients. Totally, 126 symptomatic patients who underwent gastroduodenal endoscopy were enrolled in the study. Sixty-one H. pylori strains were isolated from the patients studied. The presence of the cagL, cagA, vacA, iceA, babA2 and sabA genes in the corresponding H. pylori isolates were determined by polymerase chain reaction and the results were compared with clinical outcomes and histopathology. The cagL, cagA, vacA s1, vacA s2, vacA m1, vacA m2, iceA1, iceA2, babA 2 , and sabA genotypes were detected in 96.7, 85.2, 75.4, 24.6, 29.5, 70.5, 42.6, 23, 96.7, and 83.6 % of the isolates, respectively. The three genotypic combinations, cagL/cagA/vacAs1m1/iceA1/babA2/sabA, cagL/cagA/vacAs1m2/iceA1/babA2/sabA, and cagL/cagA/ vacAs1m2/iceA2/babA2/sabA were determined as the most prevalent combined genotypes. There was a significant correlation between the presence of cagL gene and cagA positivity (P = 0.02). No significant correlation was found between the various genotypes and clinical outcomes (P [ 0.05). The present study showed a very high prevalence of cagL genotype among the H. pylori isolates from Iranian patients. Our results demonstrated that neither single genotype nor combination genotypes of virulenceassociated genes was significantly helpful markers for predicting the severity of gastroduodenal disease associated with H. pylori infection in Iranian patients.
Aminoglycosides are potent bactericidal agents that play an important role in antistapylococcal t... more Aminoglycosides are potent bactericidal agents that play an important role in antistapylococcal therapy. In this study, we used a multiplex polymerase chain reaction assay to investigate the prevalence of aac(6 0 )-Ie=aph(2@), ant(4 0 )-Ia, and aph(3 0 )-IIIa, the genes encoding the most clinically prevalent aminoglycoside-modifying enzymes, and simultaneous detection of the methicillin resistance gene, mecA, in Staphylococcus aureus isolates. A total of 100 S. aureus clinical isolates were collected and tested by disk diffusion and agar dilution method for susceptibility testing. All isolates were screened for the presence of the three aminoglycoside-modifying enzyme genes and the methicillin resistance gene. The ant(4 0 )-Ia was the most frequent gene (58%), and aac(6 0 )-Ie=aph(2@) and aph(3 0 )-IIIa genes were found in 46% and 6% of the isolates, respectively. All isolates harboring the aac(6 0 )-Ie=aph(2@) gene were resistant to gentamicin (100% concordance). Seventy-one percent of the isolates demonstrated resistance to at least one of the aminoglycosides tested. PCR results showed that 53% of all isolates harbored the mecA gene. Aminoglycoside resistance was closely associated with oxacillin resistance ( p < 0.05). In conclusion, because of the high rate of aminoglycoside resistance among S. aureus clinical isolates observed in this study, periodic surveillance on the resistance prevalence should be performed.
World Journal of Microbiology and Biotechnology, 2014
Phenotypic identification of non-pylori Helicobacter species has always been problematic and time... more Phenotypic identification of non-pylori Helicobacter species has always been problematic and timeconsuming in comparison with many other bacteria. We developed a rapid two-step identification assay based on PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the 23S rRNA gene for differentiating between non-pylori Helicobacter species. A new genusspecific primer pair based on all available complete and partial 23S rRNA sequences of Helicobacter species was designed. In silico restriction analysis of variable regions of the 23S rRNA gene suggested SmaI and HindIII endonucleases would provide a good level of differentiation. Analysis of the obtained 23S rRNA RFLP patterns divided all Helicobacter study strains into three species groups (groups A-C) and 12 unique restriction patterns. Wolinella succinogenes also gave a unique pattern. Our proposed PCR-RFLP method was found to be as a valuable tool for routine identification of non-pylori Helicobacter species from human or animal samples.
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Papers by Babak Yadegar