[Frequency of babA2 genotype in helicobacter pylori from patient with gastroduodenal diseases in Firoozgar Hospital in Tehran]

Blood group antigen binding adhesin [babA2], is essential for attachment of Helicobacter pylori [H. pylori] to the epithelial cell layer and is the most important adhesin of H. pylori. The prevalence rate of the babA2 gene varies in different geographic areas. The aim of this study is to determine the frequency of the babA2 gene in patients with different clinical outcomes. We obtained two gastric biopsy specimens from each patient who suffered from gastrointestinal disease. Rapid urease test [RUT] was performed using one biopsy and the remaining biopsy was delivered to the laboratory for DNA extraction. Prevalence of the babA2 gene was determined using gene specific primers. A total of 56 strains [68.3%] of H. pylori were babA2 positive. The prevalence of babA2 in gastric cancer patients [84.6%] was higher than seen with gastric ulcer [66.7%], duodenal ulcer [61%], and gastric patients [66.7%]. There was no correlation between the babA2 genotype and clinical outcomes. We found that babA2 gene was more prevalent in gastric cancer but no correlation was demonstrated. However, previous studies have demonstrated a correlation of babA2 with severe H. pylori-associated diseases such as duodenal ulcers and gastric cancer. This discrepancy may be related in part to geographic diversity or sample size.

[Prevalence of periodontopathogenic bacteria in patients suffering from periodontitis using culture and PCR methods]

Periodontitis is one of the most common oral diseases with the various incidence rates in different populations. A number of bacteria are considered as the major etiologic agents of periodontitis. The aim of the present study was to determine the prevalence of periodontopathogen bacteria in patients using both PCR and culture techniques. In this study, one hundred patients [including 62 females and 38 males with an average age of 49 +/- 11.5 years] with adult periodontitis referred to periodontics department of School of Dentistry/Tehran University of Medical Sciences were investigated. The samples were taken and sent immediately to the laboratory for culture and molecular evaluation. The PCR was performed using specific primers and the statistical analysis of data was performed using SPSS statistic software and McNemar test. The results demonstrated that the total detection rate in culture method was 64%. The rate of Aggregatibacter actinomycetemcomitans [Aa] was 28% which was significantly higher than that of Porphyromonas gingivalis [Pg] [6%] and Prevotella intermedia [Pi] [3%]. 27% of cases showed mixed bacterial growth. 65% of patients were positive using molecular method. The rate of Aa [30%] was significantly higher than that of Pg [7%] and Pi [5%]. The mixed PCR positive rate containing of Aa, Pg and Pi was [23%].In this study, it was found that most of the bacteria isolated using culture and molecular methods were Aa, Pg and Pi, respectively. Although the detection frequencies of both techniques were similar, the specificity, sensitivity and bacterial detection speed of the PCR technique is obviously higher. Therefore, the use of molecular techniques is strongly recommended. However, both techniques seem to be suitable for microbiological diagnostics.