ABSTRACT
Several factors have been suggested to account for differences in the virulence of Helicobacter pylori infections in various populations. Evidence suggests the existence of different strains of H. pylori with different degrees of virulence. The present study aimed to investigate the gastric histopathology in Iranian patients infected with H. pylori and to investigate the relationship between the severity of gastritis and four different bacterial virulence-associated genotypes. All of the patients with positive results from a pathological examination, a rapid urease test, and PCR analysis for H. pylori infection were consecutively included into the study. The classification and grading of gastritis were performed according to the Sydney System. Esophagitis was classified endoscopically according to the Savary-Miller grading system. The primers used in this study targeted 16S rRNa [521 bp], Urease A [411 bp], Cag A [400 bp], and 26 kDa [303 bp]. Twenty-eight patients were included in the study. The presence of Cag A showed a significant relationship with higher gastritis grades [3.0 +/- 0.7 vs. 2.3 +/- 0.9, p = 0.024] and higher scores for H. pylori infection [3.0 +/- 0.7 vs. 2.3 +/- 0.7, p = 0.027]. The patients infected with 26 kDa-positive H. pylori had significantly higher infection scores [3.5 +/- 0.6 vs. 2.5 +/- 0.6, p = 0.020]. This study showed that CagA-positive H. pylori infection is associated with more severe gastritis and with increased bacterial density and inflammation in the biopsy specimens. The 303-bp positive genotype was also significantly associated with higher grades of esophagitis. Additional in-depth trials will be helpful in extending our findings. H. pylori [Helicobacter pylori], PCR [polymerase chain reaction]
ABSTRACT
Shigellosis is one of the major causes of morbidity in children with diarrhea in Iran. Integrons play an important role in the evolution and dissemination of multidrug resistance in gram-negative bacteria. The occurrence of integrons among Shigella spp. is frequently reported throughout the world. The aim of this study was to assess the occurrence of class 2 integrons among the multi drug resistant S. sonnei isolated from Iranian children in 2005. The study was conducted in two major pediatric hospitals in Tehran, Iran. Fecal specimens and rectal swab collected from patients were cultured and identified as Shigella by the conventional methods. Antimicrobial susceptibility test was performed according to the standard CLSI guideline. Multi-drug resistant isolates of S. sonnei were further examined for the presence of class 2 integron by PCR using specific primers. Amplicons were confirmed by restriction endonuclease analysis. A total of 83 multi-drug resistant S. sonnei strains were isolated. Of these, 45 [54%] exhibited a class 2 integron of 2.1 kbp, and 34 [41%] a class 2 integron of 1.3 kbp. Class 2 integrons were not detected in four isolates. The results showed an increased occurrence of class 2 integron carrying S. sonnei isolated from children in Tehran in 2005