Antibiotic susceptibility testing of 70 pediatric Helicobacter pylori isolates was performed by using screening agar and disk diffusion methods. Resistance to metronidazole and tinidazole was 72 to 79% and 71 to 81% by modified disk diffusion and 77% and 78% by screening agar, respectively. Susceptibilities to amoxicillin, ampicillin, clarithromycin, tetracycline, erythromycin, and ciprofloxacin were 58, 69, 75, 68, 68, and 65%, respectively.Resistance to antibiotics among Helicobacter pylori isolates is prevalent worldwide. The rate of metronidazole resistance is on the rise, and it varies according to the population studied. Resistance to amoxicillin and tetracycline has also been observed, and there are reports of high rates of resistance to clarithromycin (1-2, 4, 8-11, 16). Most antibiotic resistance studies have been done on H. pylori isolates from adults; fewer data are available for children, particularly those in developing countries. The purpose of this study was to assess the susceptibility of pediatric H. pylori isolates to commonly used antibiotics, by using the modified disk diffusion method (MDDM) and the screening agar method (SAM).During 1997 to 2000, biopsies from 250 children (median age, 9.4 years; range, 3 to 15 years) experiencing recurrent abdominal pain, nausea, and vomiting were used for bacterial culturing. Biopsies were placed within a modified Campy-Thio medium, composed of thioglycolate base medium (Difco), 10% sheep blood (SB), 8 mg of polymyxin B per liter, 2 mg of amphotericin B per liter, and 6 mg of vancomycin (Fluka) per liter and incubated at 37°C under a microaerophilic atmosphere. After 2 to 3 days, 20 l was used to streak Campy blood agar plates containing brucella agar base (Difco), 10% SB, and antibiotics. Isolates were conserved in skim milk-15% glycerol-10% fetal calf serum at Ϫ80°C, after identification by gram staining and biochemical analysis For antimicrobial susceptibility assays, a suspension was adjusted to a turbidity approximating that of a McFarland no. 3 standard, spread on SB-Mueller-Hinton agar (SBMHA) plates containing 8 mg of metronidazole or tinidazole per liter, and incubated for 3 days (5, 13). Isolates were considered susceptible or resistant if similar results were obtained from three experiments. If similar results were observed in two experiments out of three, the isolates were considered susceptible or resistant but were designated as mixed populations. For the MDDM, disks containing 4, 8, 16, 32, and 64 g of metronidazole and tinidazole (prepared from pure powders; Sigma), clarithromycin (15 g; Becton Dickinson), amoxicillin (25 g), ampicillin (10 g), erythromycin (15 g), tetracycline (30 g), and ciprofloxacin (5 g) from Padtan Tab and BioMerieux were used. Bacterial suspensions were spread on SBMHA plates, disks were added, and the diameter of the zone of inhibition was measured after 3 days. Criteria for nitroimidazole susceptibility were inhibitory zones of Ն15 to 16 mm or Ն26 mm (3, 9, 12). Quality control was ensured by using organisms from ...

Conventional bacteriology techniques were used to identify enterococci isolates cultured from patients at different hospitals in Tehran during 2000-2001. The identification was confirmed using species-specific PCR targeting the D-alanyl-D-alanine ligase gene. A total of 59 isolates of Enterococcus faecalis were identified. The rates of resistance to different antibiotics were in the following order: penicillin 84%, ciprofloxacin 42%, high-level gentamicin 30%, nitrofurantoin 14%, imipenem 4%, and chloramphenicol 2%. Resistance to ampicillin was found to be rare among the Iranian isolates of E. faecalis. Multi-locus enzyme electrophoresis was then used to analyze the strains. Forty-five electrophoretic types were obtained when 10 enzyme loci were screened. Although the collection of bacterial isolates was limited in time and location, considerable heterogeneity was found. Analysis of strains for linkage disequilibrium demonstrated that the studied population is not clonal, since the index of association was not significantly different from zero (Ia = 0.0296). Enterococcus faecalis isolates recovered from patients in Tehran were genetically diverse and seemed to possess a high potential for genetic recombinations, though none were resistant to vancomycin.

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No study has been conducted to investigate the association between dietary acid load and irritable bowel syndrome (IBS). So, this cross-sectional study was performed to investigate the association between dietary acid load and odds of IBS, its severity, and IBS subtypes. A sample of 3362 Iranian subjects was selected from health centers in Isfahan province. A validated semi-quantitative food frequency questionnaire (DS-FFQ) was applied to estimate dietary intakes. The dietary acid load was measured using net endogenous acid production (NEAP), dietary acid load (DAL), and potential renal acid load (PRAL) scores. In crude models, the highest compared with the lowest category of the PRAL score was significantly associated with increased odds of IBS severity in participants with BMI ≥ 25 (kg/m2) (OR = 1.54; 95% CI = (1.03–2.32). Also, the results indicated a significant positive association between the PARL and odds of mixed subtype of IBS (OR = 1.74; 95% CI = (1.11–2.74); P trend = 0.02). In propensity score-adjusted model with potential confounders, only a positive association was found between PRAL and odds of mixed subtype of IBS (OR = 1.78; 95% CI = (1.05–3.00); P trend = 0.03). The DAL and NEAP scores tended to show non-significant similar findings. This study indicates that dietary acid load might be associated with odds of mixed type of IBS. However, further research is warranted to infer these findings.