Background and Aims. Helicobacter pylori is a common infectious bacterium mostly found in gastroduodenal diseases. The increased prevalence of clarithromycin-resistant H. pylori strains is a major challenge in the successful treatment of infections caused by this organism. The present study is aimed at detecting the clarithromycin resistance pattern of H. pylori strains isolated from gastric biopsies and evaluating point mutations of the 23S rRNA gene. Patients and methods. In the present descriptive cross-sectional study, 165 patients with gastrointestinal disorders, who were referred to the Endoscopy Center of Dr. Shariati Hospital of Isfahan, Iran, were enrolled from April to July 2018. H. pylori infection was diagnosed by culture, and susceptibility of the isolates to clarithromycin was assessed by the E-test. Minimum inhibitory concentration (MIC) values were obtained based on EUCAST recommendations. Also, fluorescence in situ hybridization (FISH) was used to determine point mutations associated with clarithromycin resistance. Results. By using culturing, H. pylori was isolated from 50.3% (83/165) gastric biopsy specimens. The overall frequency of resistance to clarithromycin was 25.3% (21/83) by the E-test. In the resistance genotypic analysis, 19 isolates had mutations. The prevalence of A2143G and A2144G mutations was 68.4% (13/19) and 31.5% (6/19), respectively. A2143C mutation was not tracked in any isolate. Two isolates with MIC > 0:5 μg/mL had no mutations that could be related to other mechanisms of resistance. Conclusion. As presented in the study, the high prevalence of clarithromycin-resistant H. pylori due to point mutations of the 23S rRNA gene indicates the necessity of revising the standard treatment regimen based on antibiotic susceptibility pattern of each region.

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Background: Resistance to clarithromycin in Helicobacter pylori has become one of the most important reasons for failure of antibiotic eradication therapies. This resistance is predominantly caused by point mutations in the peptidyl transferase region of 23S rRNA. Objectives: The aim of this study was to determine the prevalence of the A2143G, A2144G, and A2143C point mutations among H. pylori strains from gastric biopsy specimens in Bushehr, in the southwest of Iran. Patients and Methods: Gastric biopsy specimens were obtained from patients with upper gastrointestinal symptoms during endoscopy. Fluorescent in situ hybridization (FISH) using oligonucleotide probes was applied to detect the point mutations responsible for clarithromycin resistance in H. pylori. Results: Of the 135 H. pylori-positive specimens, two harbored strains with the A2143G mutation and nine contained strains with the A2144G mutation. Thus, the prevalences of the A2143G and A2144G point mutations were 1.5% and 6.7%, respectively. The A2143C point mutation was not found. Conclusions:The prevalences of the point mutations A2143G and A2144G were low in our geographic area. Based on the findings of this study, clarithromycin still seems to be a useful antibiotic for initial treatment regimens in Bushehr, Iran.

Background: Mycobacterium tuberculosis is an infectious agent responsible for major health problems and a large number of mortalities. The prevalence of Mycobacterium tuberculosis infection varies across countries. Knowing the infection prevalence can aid in improving public health and reduce the associated costs. The aim of this study was to determine the prevalence of tuberculosis (TB) infection in suspected cases in Mashhad, Iran.Methods: All the clinical specimens suspected of TB infection were sent to a laboratory for diagnosis during -March 2017 to March 2018. The samples were analyzed microscopically using Ziehl–Neelsen staining, by polymerase chain reaction (PCR) to identify the Mycobacterium tuberculosis species using IS6110 primers, and the samples were also grown on Lowenstein–Jensen medium.Results: Of 2,755 clinical samples analyzed, 153 (5.55%) were identified as Mycobacterium tuberculosis-positive, of which 54.9% originated from females and 45.1% from males. The highest rate of infection was observed in spring, especially in May (15%). Most TB cases were found in patients in VIP (43.1%), thorax (17%), and internal (15%) wards. TB infection was mostly detected in bronchial tube (70%) and sputum (23.5%) samples. The most common positive smear was 1+ (36%). Of the 153 cases, (147) 96.1% were culture –positive and 2% were PCR-negative also 84.3% were smear –positive.Conclusion: The highest rate of infection occurred in spring, when the number of religious tourists entering the city was at its peak. Considering the sensitive location of this city, awareness regarding TB status can lead to improved health in the community and development of basic strategies to control and eliminate the transmission of this infection from Mashhad to other areas.

Acinetobacter baumannii, as a nosocomial pathogen has become a worldwide concern in recent years. In the current study, the resistance to tetracyclines and colistin were assessed in the isolates from different provinces of Iran.During the timeline of this study, a number of 270 isolates of A. baumannii were collected from tracheal aspirates, wounds, urine and blood cultures. The minimum inhibitory concentration (MIC) for tetracycline, doxycycline, minocycline, tigecycline and colistin were evaluated. Tetracycline resistance genes were assessed by PCR. The mean expression level of adeB, adeJ and adeG were assessed using semi quantitative Real-Time PCR. The clonal relationship of the isolates was evaluated by the repetitive extragenic palindromic PCR (REP-PCR), International Clonal (IC) Lineage Multiplex PCR and multilocus sequence typing (MLST) (Pasteur scheme) methods.The MIC by microdilution method showed that 87.5, 51.4, 28, 0.74 and 0% of the isolates were resistant to tetracycline, doxycycline, minocycline, tigecycline and colistin respectively. The prevalence of tetracycline resistance genes was 99.2, 99.2, 98, 86.7, 10, 3.33, 0.37, 0% for adeB, adeJ, adeG, tetB, tetA(39), tetA, tetM and tetH in tetracycline-resistant isolates. Moreover, the expression level of adeB, adeJ, adeG genes in tigecycline-nonsusceptible A. baumannii (TNAB) strain was higher compared to the tigecycline-susceptible A. baumannii (TSAB). A broad genomic diversity was revealed, but ST2 was the most prevalent ST. Our results indicated that tetracycline resistance in Iran is mediated by resistance-nodulation-cell division (RND) and tetB efflux pumps.