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.

Background:Dental caries is one of the most prevalent infectious diseases affecting humans of all ages. Streptococcus mutans has an important role in the development of dental caries by acid production. The purpose of this study was to evaluate the antibacterial and biofilm disinfective effects of the oak tree Quercus infectoria galls against S. mutans.Materials and Methods:The bacterial strain used in this study was S. mutans (ATCC: 35668). Two kinds of galls, Mazouj and Ghalghaf were examined. Galls were extracted by methanol, ethanol and acetone by Soxhlet apparatus, separately. Extracts were dissolved in sterile distilled water to a final concentration of 10.00, 5.00, 2.50, 1.25, 0.63, 0.31, and 0.16 mg/ml. Microdilution determined antibacterial activities. The biofilm removal activities of the extracts were examined using crystal violet-stained microtiter plate method. One-way ANOVA was used to compare biofilm formation in the presence or absence of the extracts.Results:The methanolic, ethanolic, and acetonic extracts of Q. infectoria galls showed the strong inhibitory effects on S. mutans (P < 0.05). The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for the Mazouj and Ghalghaf gall extracts against S. mutans were identical. The MIC values ranged from 160 μg/ml to 320 μg/ml, whereas the MBC values ranged from 320 μg/ml to 640 μg/ml. All extracts of Q. infectoria galls significantly (P < 0.05) reduced biofilm biomass of S. mutans at the concentrations higher than 9.8 μg/ml.Conclusion:Three different extracts of Q. infectoria galls were similar in their antibacterial activity against S. mutans. These extracts had the highest biofilm removal activities at 312.5 μg/ml concentration. The galls of Q. infectoria are potentially good sources of antibacterial and biofilm disinfection agent.

Human bocavirus (HBoV) was first characterized in nasopharyngeal aspirates from young children with acute respiratory infections. It is prevalent among children with acute wheezing. This study was carried out in order to analyze the infection frequency and coinfection rates of HBoV with respiratory syncytial virus (RSV) and to perform phylogenetic analysis of HBoV in samples of children with acute respiratory infection in Isfahan, Iran. During the time period 2016-2017, altogether 75 respiratory samples from children hospitalized with acute respiratory infection were collected. The samples were first screened for RSV by direct immunofluorescence method and then subjected to detect HBoV DNA by PCR. Genotyping of HBoV-positive samples was conducted by direct sequencing of PCR products using NP and VP1/VP2 genes. Out of 75 respiratory samples, 20 (26.7%) and 10 (13.3%) were positive for RSV and HBoV, respectively. The coinfection rate was 40% (p = 0.048). Considering the seasonal distribution, winter has the highest extent outbreak (p = 0.036). Sequence analysis of positive samples exhibits that all of the isolated HBoV were related to genotype 1 (HBoV-1) with minimal sequence variations. Increasing frequency of HBoV suggests that the virus is related to acute respiratory infection in children. A single genetic lineage of HBoV1 seems to be the major genotype in Iran.

BackgroundAcinetobacter baumannii is an important human pathogen which has recently gained increased attention due to the occurrence of drug-resistant nosocomial infections in patients suffering from immune system disorders, and those in hospital intensive care units. The aim of this research was to identify and isolate A. baumannii strains resistant to colistin, determine antibiotic resistance pattern of this bacteria, investigate the presence of colistin-resistant genes, and finally assess the effect of expression changes in pmrA and pmrB genes resistant to A. baumannii against colistin via real-time polymerase chain reaction.MethodsThe samples were initially purified and isolated using biochemical tests and Micro-gen kit. Later, the resistance pattern evaluation of validated samples to different antibiotics and colistin was carried out using two methods viz., disc diffusion and E-test. This was followed by the assessment of genes resistant to colistin via polymerase chain reaction besides gene expression changes via real-time polymerase chain reaction.ResultsThe results of this study indicated that eleven strains of A. baumannii isolated from Shahid Rajaee Trauma Hospital were resistant to colistin. However, in the resistance pattern evaluation of A. baumannii isolated from Ali Asghar Hospital, all the strains were sensitive to colistin. In the evaluation of genes resistant to pmrA and pmrB, most of the strains resistant to colistin were carriers of these genes. Besides, in the expression assessment of these genes, it was demonstrated that expression of pmrA in the strains resistant to colistin significantly increased in relation to sensitive strains, but the expression of pmrB increased at a lower rate in the strains resistant to colistin as compared to the sensitive strains.ConclusionThus, it can be safely mentioned that increased expression of pmrA was due to the resistance of A. baumannii to colistin.

Background Widespread misuse of antibiotics caused bacterial resistance increasingly become a serious threat. Bacteriophage therapy promises alternative treatment strategies for combatting drug-resistant bacterial infections. In this study, we isolated and characterized a novel, potent lytic bacteriophage against multi-drug resistant (MDR) Acinetobacter baumannii and described the lytic capability and endolysin activity of the phage to evaluate the potential in phage therapy. Methods A novel phage, pIsf-AB02, was isolated from hospital sewage. The morphological analysis, its host range, growth characteristics, stability under various conditions, genomic restriction pattern were systematically investigated. The protein pattern of the phage was analyzed, and the endolysin activity of the phage was determined under the non-denaturing condition on SDS-PAGE. The optimal lytic titer of phage was assessed by co-culture of the phage with clinical MDR A. baumannii isolates. Finally, HeLa cells were used to examine the safety of the phage. Results The morphological analysis revealed that the pIsf-AB02 phage displays morphology resembling the Myoviridae family. It can quickly destroy 56.3% (27/48) of clinical MDR A. baumannii isolates. This virulent phage could decrease the bacterial host cells (from 108 CFU/ml to 103 CFU/ml) in 30 min. The optimum stability of the phage was observed at 37 °C. pH 7 is the most suitable condition to maintain phage stability. The 15 kDa protein encoded by pIsf-AB02 was detected to have endolysin activity. pIsf-AB02 did not show cytotoxicity to HeLa cells, and it can save HeLa cells from A. baumannii infection. Conclusion In this study, we isolated a novel lytic MDR A. baumannii bacteriophage, pIsf-AB02. This phage showed suitable stability at different temperatures and pHs, and demonstrated potent in vitro endolysin activity. pIsf-AB02 may be a good candidate as a therapeutic agent to control nosocomial infections caused by MDR A. baumannii.

Objective: Acinetobacter baumannii is responsible for most nosocomial infections in hospitals. It has the ability to form bio lms and has a high degree of antibiotic resistance. Colistin is one of the last therapeutic options for the treatment of Multi Drug Resistance infections. Recently, strains of this pathogen resistance to the colistin were reported increasingly. Therefore, alternative antibacterial methods such as phage therapy are being researched.Results: From 15 MDR A. baumannii clinical isolates, 26.6% were resistant to colistin, 80% were able to produce strong bio lm, and 20% produce weak bio lm. The isolated lytic phage (IsfAB78) was able to reduce the bio lm by up to 87%. Since most of the MDR colistin-resistant strains produce bio lm, and MDR A. baumannii infections are di cult to treat, development of phage therapy could be an alternative in the future. Phage IsfAB78 is a good candidate for this purpose.

Background Pseudomonas aeruginosa is an aerobic gram-negative bacillus that is the cause of a range of opportunistic infections in humans. P. aeruginosa is one of the most important pathogenic bacteria in the development of nosocomial infections such as pneumonia associated with intensive care unit (ICU) ventilator, bacteremia, urinary tract infections, and infection in people with severe and septic burns (1, 2). Infections caused by P. aeruginosa are often severe and lifethreatening. P. aeruginosa infection is difficult to control and eliminate because it has intrinsic resistance to many antimicrobial agents (3). The rapid increase of extendedspectrum beta-lactamase (ESBL)-producing isolates of P. aeruginosa is a health risk. Many isolates of P. aeruginosa are susceptible to cephalosporins and carbapenems; however, this bacterium has acquired resistance to these antibiotics. P. aeruginosa resistance mechanisms include ß-lactamase production, efflux pumps and changes in outer membrane proteins. Multi-drug resistant (MDR) strain of P. aeruginosa is able to produce a wide range of beta-lactamase enzymes. According to Ambler classification, beta-lactamases are divided into four groups based on their structures (A-D). P. aeruginosa resistance to cephalosporins, monobactam and carbapenems may be acquired by ESBL enzymes (4,5). The prevalence of resistance to carbapenems among P. aeruginosa isolates is a common challenge facing the successful treatment of the life-threatening and permanent infections due to this bacterium (6,7). Proper and up-to-date information about the antibiotic resistance of clinical isolates of P. aeruginosa is essential for the treatment of the infections caused by these strains. The aim of this study was to investigate the presence of bla SHV , bla TEM , bla CTX-M and bla OXA-48 beta-lactamase genes in the clinical isolates of P. aeruginosa in Bandar Abbas, Iran. Materials and Methods In this descriptive study, 96 P. aeruginosa strains isolated from wound patients hospitalized in Bandar Abbas Hospital from May to December 2017 were studied. Identification of these isolates was confirmed using Gram staining and biochemical tests including catalase and oxidase tests, fermentation in oxidation-fermentation

Background and Purpose: Due to the fact that fungal species such as Aspergillus flavus and Aspergillus parasiticus produce carcinogenic and mutagenic aflatoxins and have the potential to produce fungal secondary metabolites, fungal contamination should be avoided. This study was conducted using the HPLC method and was aimed at examining the fungal contamination of Isfahan hazelnuts in order to identify the presence of Aflatoxins. Materials and Methods: One hundred samples of hazelnuts were randomly collected from supermarkets in Isfahan. The samples were then cultured on Sabouraud dextrose agar (SDA) media and analyzed to determine fungal contaminations. The aflatoxin analysis was carried out using the HPLC method. Results: It was discovered that nine genera of fungi, namely Aspergillus, Penicillium , Rhizopus, Ulocladium, Alternaria, Drechselera, Trichothecium, Scopulariopsis, and Mucor were identified in 78% of the samples. Samples contaminated with Aspergillus flavus (22 samples) were studied to determine the presence of aflatoxin. The results showed that 16 (72.72%) of the samples were contaminated with AFB1, AFB2 and AFG2 and the mean concentrations were 0.926, 0.563 and 0.155ng/g, respectively. Conclusions: Some parameters that affect mycotoxin production are temperature, food substrate, strain of the mold and other environmental factors. Due to the toxigenic quality of some of these fungi and their hazard to human health, it is crucial that fungal contamination and aflatoxin identification tests are carried out before certain products are made available to the mass market.