ABSTRACT In the province of Quebec, Canada, from 1996 to 1998, 3,650 invasive Streptococcus pneumoniae infections were reported. A total of 1,354 isolates were serotyped and tested for antimicrobial susceptibility. The distribution of serotypes remained stable over the 3 years, with serotypes 14, 6B, 4, 9V, 23F, and 19F accounting for 61% of the isolates. Overall, 90% of isolates were included in the current 23-valent vaccine and 67% were included in the 7-valent conjugate vaccine. We were able to determine that resistance to penicillin and to other antibiotics is increasing.

Helicobacter pylori has an unusual pattern of genetic variation, which complicates research on this organism. To gain a better understanding of the forces behind this phenomenon, the extent to which recombination and single point mutations affect genetic variability in H. pylori was quantified and the influence of both geographical distance and clinical background were assessed. Site-directed restriction-endonuclease digestion of 2 gene fragments was performed on 168 isolates from Montreal and Berlin. Allelic diversity was found to be much higher for H. pylori than for other bacterial species. This finding is consistent with those of previous studies on H. pylori that were conducted using other techniques. However, nucleotide diversity was within the range reported for other bacterial species. Phylogenetic analysis found no grouping of strains with clinical background or geographical origin. Recombination at a rate that resulted in linkage equilibrium within genes can explain these observations.

OBJECTIVE:In light of evidence that Helicobacter pylori treatment fails 5% to 20% of the time, the objective of this study was to determine predictors of unsuccessful H. pylori eradication and of duodenal ulcer recurrence.DESIGN:Randomized, double-blind, placebo-controlled trial.SETTING:Gastroenterology services of 2 general hospitals in Montreal, Que.PATIENTS:All patients (aged 16 to 90) with an endoscopically proven duodenal ulcer within the previous year and H. pylori infection detected on antral biopsy were asked to participate; 85 were included.INTERVENTIONS:Patients were randomized in double-blind fashion to 1 of 2 eradication therapies, consisting of metronidazole, bismuth subcitrate and either amoxicillin or placebo. Endoscopy was performed at follow-up every 3 months for 12 months.OUTCOME MEASURES:Demographic data, characteristics of patients and disease, previous history and family history of ulcer disease, compliance at day 10 and day 28 of therapy; in vitro metronidazole resistance of H. pylori; eradication of H. pylori (determined by endoscopic biopsy 3 months after therapy); and ulcer recurrence within 12 months after therapy.RESULTS:Metronidazole resistance (odds ratio [OR] 0.11, 95% confidence interval [CI] 0.017 to 0.69) was the only independent predictor of eradication. Compliance (as defined in the study), density of organisms on culture, as well as several other factors examined, were not significant predictors. Treatment group, although a significant factor on univariate analysis, was not an independent predictor on multivariate analysis, as there were relatively good eradication rates (82% and 97% among compliant patients) in both groups. With regard to ulcer recurrence, 3 independent predictors were identified: failed H. pylori eradication (OR 86.5, 95% CI 4.2 to 1769), unemployment (OR 13.2, 95% CI 1.8 to 95) and a family history of ulcer disease (OR 12.2, 95% CI 1.2 to 128).CONCLUSIONS:The best predictor of ulcer recurrence is failure of H. pylori eradication, which, in turn, depends on metronidazole resistance. Hence, treatments containing metronidazole should be avoided in populations with high rates of metronidazole resistance. A family history of ulcer disease and unemployment were also predictors of ulcer recurrence, which suggests a potential role for treatment of contacts.

Introduction: H. pylori infection causes increased gastric mucosal reactive oxygen species (ROS) and reduced gastric juice ascorbic acid levels, processes that may underlie the increased risk of developing gastric cancer• We have studied the effect of supplementing dietary antioxidant vitamins in combination with H. pylori eradication on these mechanisms in a randomised, double blind, placebo controlled trial.Methods: Following gastroscopy, H. pylori positive patients (based on uease test, culture and histology) were randomised into four groups: Bismuth chelate 120mg qds, tetracycline 500mg qds, metronidazole 400rag tds (BTM) or placebo (plac) for 2 weeks, followed by vitamin C (200mg bd) and vitamin E (50mg bd) (vits) or placebo for four weeks.Gastroscopy was repeated at six weeks.Samples were taken for assay of plasma, gastric juice, and antral ascorbic acid (PAA ()amol/ml), JAA (~tmol/ml), AAA 0amol/g)) using HPLC, lipid peroxidation using thiobarbituric acid extraction of malondialdehyde (MDA) (pmol/g), and ROS estimation by chemiluminescence (cpm/mg).Results: 56 patients had normal gastric mucosa; 98 H. pylori positive patients returned for follow up.Mean ages 35 and 49 yrs, respectively.For patients receiving antibiotics, only data for those with successful eradication (36/49, 73.5%) is included.No significant changes were seen in the placebo group.

It has been recommended that ventilation of health care facilities should be monitored regularly to reduce the risk of nosocomial transmission of tuberculosis. We developed a simple method to measure air-change rates and direction of airflow in patient care areas. Pure carbon dioxide (CO2) was released at 13.5 L/min for 5 min, then measured for 30 min within the room and outside in the hallway. Smoke tubes were also used to measure direction of airflow. Doors and windows (if openable) were manipulated. This protocol, when conducted in five offices in 30 patients care areas in two hospitals, provided good mixing and reproducible decay curves, with less than 15% coefficient of variation for repeated measures over a wide range of air-change rates. Manipulation of door and/or window produced significant changes in air-change rates and airflow direction, although calculated air-change rates were more variable. Smoke tube measurements were inconsistent, agreed poorly with evidence of CO2 movement from room to hall, and were strongly affected by room to hallway temperature differentials. CO2 release and measurement proved to be a simple, yet reliable, method to measure air-change rates and the effect of door or window manipulation. Smoke tube measurements were not reliable to characterize direction of airflow.

To determine whether omeprazole eradicates Helicobacter pylori infection of the gastric antrum, six adolescents and one adult with H. pylori colonization of the antrum were entered into a clinical, open trial of medical therapy. Histologic evidence of antral gastritis and three complementary methods to document H. pylori colonization of the stomach (silver stain, urease testing, and culture of antrum) were obtained before and after an 8-week course of omeprazole. In vitro susceptibility to omeprazole and restriction endonuclease analysis were performed on H. pylori isolates obtained from patients before and after omeprazole therapy. Each of the seven patients treated with omeprazole had continued active inflammation in the antrum and one or more features indicative of persisting H. pylori colonization. Minimum inhibitory concentrations and DNA fingerprints of H. pylori isolated after therapy were identical to those of the pre-treatment bacterial isolates in each of the four subjects examined. We conclude that omeprazole therapy alone did not eradicate H. pylori infection of the human antrum. Continued bacterial colonization was not related to either acquired bacterial resistance to the drug or reinfection of the stomach with a different H. pylori strain.