Antibiotic susceptibility profile of Helicobacter pylori isolated from the dyspepsia patients in Tehran, Iran

Helicobacter pylori is an important pathogen for gastroduodenal diseases. Infection with H. pylori can be limited by regimens of multiple antimicrobial agents. However, antibiotic resistance is a leading cause of treatment failure. The aim of this study has been to determine the resistance patterns of H. pylori strains isolated from gastric biopsies of patients with dyspepsia by agar dilution method, in Tehran, Iran. H. pylori isolates from patients with gastrointestinal diseases were evaluated for susceptibility testing by agar dilution method. Susceptibility testing was performed to commonly used antibiotics including clarithromycin, tetracycline, amoxicillin, metronidazole and ciprofloxacin. Among 92 patients with dyspepsia, H. pylori strains were isolated from 42 patients. Seventeen [40.5%] of the isolates were resistant to metronidazole [MICs >/= 8 microg/1], whereas one isolate [2.4%] was resistant to amoxicillin [MICs

Molecular detection and antimicrobial resistance of diarrheagenic Escherichia coli strains isolated from diarrheal cases

To identify and classify Iranian isolates of diarrheagenic Escherichia coli E. coli on the basis of presence of virulence genes and to determine antibiotic susceptibility of isolated strains. The current cross-sectional study was conducted in 2005 at the Pasteur Institute, Tehran, Iran. One hundred and ninety-three diarrheagenic E. coli isolated from diarrheal patients in different regions of Iran were included in current study. Virulence factor genes for diarrheagenic E. coli were detected by polymerase chain reaction. Of the 193 diarrheagenic E. coli detected by PCR, 86 44.5% were Shiga toxin-producing E. coli STEC, 74 38.4% enteropathogenic E. coli EPEC, 19 9.8% enteroaggregative E. coli, and 14 7.3% enterotoxigenic E. coli isolates. Susceptibility to 12 clinically important antimicrobial agents was determined for 193 strains of diarrheagenic E. coli. A high incidence of resistance to tetracycline 63%, ampicillin 62%, streptomycin 56%, amoxicillin/clavulanic acid 44.5%, trimethoprim/sulfamethoxazole 39.5%, and cephalothin 37% was observed. The STEC and EPEC strains with high resistance to tetracycline and ampicillin, but highly susceptible to quinolones are among the most important causative agent of diarrhea in Iran. This study suggests that antimicrobial resistance is widespread among E. coli strains colonizing Iranian patients. Guidelines for appropriate use of antibiotics in developing countries require updating