The epidemiology of Helicobacter pylori resistance in a university affiliated hospital: a comparison between two time periods-a cross-sectional design.

PURPOSE: During the last few decades, the increased use of various types of antibiotics in the general population caused a significant change in regional Helicobacter pylori (H. pylori) antibiotic resistance. Our aim is to study the changes in H. pylori resistance in patients who had undergone an esophagogastroduodenoscopy (EGD) and susceptibility testing and found positive for H. pylori. The study was conducted in a university affiliated hospital between 2013-2020. METHODS: A cross-sectional study was performed on all consecutive patients who had undergone an EGD and tested positive for H. pylori at the Kaplan Medical Center, Israel. The study period was divided into two sub-periods: 2013-2016 and 2017-2020. Data on age, sex, comorbidities, previous treatments, and antimicrobial susceptibility testing for six antimicrobial agents were compared. RESULTS: The resistance rates of H. pylori to clarithromycin and dual resistance to clarithromycin and metronidazole were found significantly higher during the late period. Multivariable analysis showed that the later period, older age, and diabetes mellitus were independent predictors for antimicrobial resistance. CONCLUSIONS: Our study has shown that there is an increasing resistance of H. pylori to clarithromycin and metronidazole while its susceptibility is unaffected with time to other antibiotics. More recent cross-sectional studies with larger samples are warranted in order to evaluate the changes in the resistance patterns of H. pylori to various antibiotics with time.

Early effectiveness of BNT162b2 Covid-19 vaccine in preventing SARS-CoV-2 infection in healthcare personnel in six Israeli hospitals (CoVEHPI).

BACKGROUND: Methodologically rigorous studies on Covid-19 vaccine effectiveness (VE) in preventing SARS-CoV-2 infection are critically needed to inform national and global policy on Covid-19 vaccine use. In Israel, healthcare personnel (HCP) were initially prioritized for Covid-19 vaccination, creating an ideal setting to evaluate early real-world VE in a closely monitored population. METHODS: We conducted a prospective study among HCP in 6 hospitals to estimate the effectiveness of the BNT162b2 mRNA Covid-19 vaccine in preventing SARS-CoV-2 infection. Participants filled out weekly symptom questionnaires, provided weekly nasal specimens, and three serology samples - at enrollment, 30 days and 90 days. We estimated VE against PCR-confirmed SARS-CoV-2 infection using the Cox Proportional Hazards model and against a combined PCR/serology endpoint using Fisher's exact test. RESULTS: Of the 1567 HCP enrolled between December 27, 2020 and February 15, 2021, 1250 previously uninfected participants were included in the primary analysis; 998 (79.8%) were vaccinated with their first dose prior to or at enrollment, all with Pfizer BNT162b2 mRNA vaccine. There were four PCR-positive events among vaccinated participants, and nine among unvaccinated participants. Adjusted two-dose VE against any PCR-confirmed infection was 94.5% (95% CI: 82.6%-98.2%); adjusted two-dose VE against a combined endpoint of PCR and seroconversion for a 60-day follow-up period was 94.5% (95% CI: 63.0%-99.0%). Five PCR-positive samples from study participants were sequenced; all were alpha variant. CONCLUSIONS: Our prospective VE study of HCP in Israel with rigorous weekly surveillance found very high VE for two doses of Pfizer BNT162b2 mRNA vaccine against SARS-CoV-2 infection in recently vaccinated HCP during a period of predominant alpha variant circulation. FUNDING: Clalit Health Services.

High Metronidazole and Clarithromycin Resistance of Helicobacter Pylori Isolated from Previously Treated and Naïve Patients.

BACKGROUND: Antimicrobial resistance is the main determinant for Helicobacter pylori treatment failure. Regional antimicrobial susceptibility testing is essential for appropriate antibiotic selection to achieve high eradication rates. OBJECTIVES: To assess primary and secondary H. pylori resistance in isolates recovered from Israeli naïve and treatment failures. To identify predictors of resistance. METHODS: In this retrospective study, in vitro activity of isolated H. pylori in Israel was tested against metronidazole, clarithromycin, tetracycline, amoxicillin, and levofloxacin in 128 isolates: 106 from treatment failures and 22 from naïve untreated patients. The minimal inhibitory concentration values were determined according to the Etest instructions. Treatment failures previously failed at least one treatment regimen. RESULTS: No resistance to amoxicillin and tetracycline was detected. Resistance to metronidazole and clarithromycin was high in H. pylori isolates both from treated and untreated patients: 68.9%, 68.2% for metronidazole (P = 0.95); 53.8%, 59.1% for clarithromycin (P = 0.64), respectively. Dual resistance to clarithromycin and metronidazole was seen in 45.3% and 50%, respectively (P = 0.68). Resistance to levofloxacin was detected in two (1.9%) isolates from treated patients. Simultaneous resistance to clarithromycin, metronidazole, and levofloxacin was seen in an isolate from a treated patient. Age was the only predictor of resistance to metronidazole and clarithromycin. CONCLUSIONS: The resistance rates to both single and dual metronidazole and clarithromycin in isolates recovered from both Israeli naïve and treated patients is high. Low resistance renders levofloxacin an attractive option for second or third line treatment. Therapeutic outcome would benefit from susceptibility testing after treatment failure.

Primary and Secondary Antibiotic Resistance of Helicobacter pylori in Israeli Children and Adolescents.

BACKGROUND: Empiric treatment for Helicobacter pylori is influenced by antibiotic susceptibility of infecting strains. A rise in the resistance rate to clarithromycin and metronidazole has been reported in pediatric populations. OBJECTIVES: To assess the primary and secondary antibiotic resistance of H. pylori isolates in Israeli children and adolescents. METHODS: A retrospective review of H. pylori isolates cultured from antral biopsies of consecutive children aged 1 to 18 years, who were referred to the Pediatric Gastroenterology Unit, Kaplan Medical Center, over a 2.8 year period, was performed. Antibiotic susceptibility to clarithromycin, metronidazole, amoxicillin, tetracycline, and levofloxacin was determined by E-test. Data on the age of the patient, indication for endoscopy, and antibiotic treatment for H. pylori in previously treated children was collected. RESULTS: Cultures for H. pylori yielded 123 isolates. In children not previously treated (n=95), the primary global resistance was 38% with resistance to clarithromycin 9.5%, metronidazole 32.6 %, and to both 4.2%. Respective rates of resistance in previously treated children (n=28) were 71% (P = 0.002), 29% (P = 0.02), and 61% (P = 0.007). Simultaneous resistance to both drugs was found in 18% (P = 0.02). All H. pylori strains were susceptible to amoxicillin, tetracycline, and levofloxacin. Past eradication treatment was the only independent risk factor for antibiotic resistance in multivariate analysis. CONCLUSIONS: Significantly higher resistance rates were found in previously treated patients, stressing the need to refrain from empiric treatment using the "test and treat strategy." Culture-based treatment strategy should be considered in all previously treated children.