Nabi Jomehzadeh

Background and Aim: Escherichia coli is a key pathogen responsible for various infections, such as urinary tract infections, gastroenteritis, and wound infections. The increasing occurrence of antimicrobial resistance, particularly in extended‐spectrum β‐lactamase (ESBL)‐producing strains, poses a significant global health threat. This study aimed to assess the prevalence of fosfomycin resistance genes in ESBL‐producing E. coli isolates from Abadan, southwest Iran. Methods: From December 2020 to June 2021, 90 E. coli isolates were obtained from clinical labs and healthcare centers affiliated with Abadan University of Medical Sciences. Antimicrobial susceptibility and ESBL production were determined using the disk diffusion method, while polymerase chain reaction was employed to detect relevant resistance genes. Results: Fosfomycin resistance was observed in 5.6% of E. coli isolates. ESBL production occurred in 31.1% of isolates, with over half (53.6%) carrying the bla _CTX‐M gene. Among ESBL producers, the glpT gene was the most prevalent (50%), followed by fosA3 (10.7%) and fosC2 (3.6%). Notably, the fosA gene was absent in all examined isolates. Conclusion: This study reveals a rising prevalence of fosfomycin resistance among ESBL‐producing E. coli isolates in Abadan, Iran. Ongoing surveillance of fosfomycin resistance is crucial for informing effective antimicrobial stewardship and treatment strategies.

Helicobacter pylori infection has been extensively studied in relation to various gastrointestinal disorders, with emerging evidence suggesting a significant association with inflammatory bowel disease (IBD). Epidemiological studies consistently demonstrate an inverse relationship between H. pylori infection and IBD development, particularly Crohn's disease (CD). Meta‐analyses reveal a significantly lower prevalence of H. pylori among IBD patients compared to healthy controls, supporting the hypothesis of a potential protective effect. This negative correlation appears particularly strong for virulent strains expressing CagA , suggesting strain‐specific immunomodulatory properties. The protective mechanisms may involve H. pylori 's ability to modulate host immune responses and maintain gut microbial homeostasis. Experimental models show that H. pylori colonization can induce regulatory T‐cell responses and downregulate pro‐inflammatory cytokines, potentially creating an immunological balance that protects against IBD development. Conversely, H. pylori eradication has been associated with increased IBD incidence and disease flares, possibly through disruption of established microbial ecosystems and immune regulation. Clinical observations further support this relationship, demonstrating that H. pylori ‐positive CD patients often experience milder disease courses with fewer complications. However, the interaction remains complex, as H. pylori infection may also exert detrimental effects in certain contexts. The bacterium's influence appears to depend on multiple factors, including infection timing, strain characteristics, and host genetic background. Current evidence highlights the crucial interplay between H. pylori , gut microbiota composition, and mucosal immunity in shaping IBD pathogenesis. Future research should focus on elucidating precise molecular mechanisms and evaluating whether targeted modulation of H. pylori could offer therapeutic potential, while considering potential risks.

The manuscript presents a novel approach for the synthesis of nickel nanoparticles (Ni NPs) utilizing an ionic liquid-based extract derived from Amaranthus viridis. The authors have conducted a thorough characterization of the synthesized Ni NPs and...

Objective: The global emergence of carbapenem‐resistant Klebsiella pneumoniae is considered a significant contemporary concern., as carbapenems are the last resort for treating infections caused by multidrug‐resistant Gram‐negative bacteria. This study aimed to investigate the carbapenem‐resistance genes in extended‐spectrum β‐lactamase producing K. pneumoniae isolates.Methods: Seventy‐five non‐duplicate clinical K. pneumoniae strains were isolated from urine, blood, sputum, and wound samples. Antimicrobial susceptibility tests for 12 different antibiotics were performed using the disk diffusion method, followed by determining minimum inhibitory concentrations of imipenem and meropenem. Phenotypic detection of extended‐spectrum β‐lactamase and carbapenemase enzymes was performed by double‐disc synergy test and modified Hodge test, respectively. PCR assay further investigated resistant isolates for extended‐spectrum β‐lactamase and carbapenemase‐encoding genes.Results: The highest and lowest resistance rates were observed against ampicillin (93.3%) and tigecycline (9.3%). According to phenotypic tests, 46.7% of isolates were positive for extended‐spectrum β‐lactamase enzymes and 52.8% for carbapenemase. A total of 11 isolates contained carbapenemase genes, with bla_OXA‐48 (19.4%; 7/36) being the predominant gene, followed by bla_NDM (8.3%; 3/36).Conclusion: The study's findings reveal the alarming prevalence of beta‐lactamase enzymes in K. pneumoniae strains. Early detection of carbapenem‐resistant isolates and effective infection control measures are necessary to minimise further spread, as carbapenem resistance has become a public health concern.

Background: Carbapenem-resistant clinical isolates are extending rapidly, and in past recent years, carbapenem resistance has become an important health problem worldwide. This study aimed to investigate the carbapenem-resistance genes in extended-spectrum β-lactamase (ESBL) producing K. pneumoniae isolates. Methods: Seventy-five non-duplicate clinical K. pneumoniae strains were isolated from urine, blood, sputum, and wound samples. Antimicrobial susceptibility tests for 12 different antibiotics were performed using the disk diffusion method, followed by the determination of minimum inhibitory concentrations (MIC) of imipenem and meropenem. Phenotypic detection of ESBL and carbapenemase enzymes was performed by disk Disc Diffusion Synergy test (DDST) and modified Hodge test (MHT), respectively. Resistant isolates were further investigated for ESBL and carbapenemase genes by the PCR assay. Results: The highest and lowest resistance rates were observed against ampicillin (93.3%) and tigecycline (9.3%), respectively. Based on the results of phenotypic tests, 46.7% and 25.3% were positive for ESBL and carbapenemase enzymes, respectively. In addition, using the molecular method, the predominant ESBL-, and carbapenemase-associated genes were bla_TEM (34.3%) and bla_OXA-48 (57.8%), respectively. Conclusion: Based on the study, it has been found that K. pneumoniae strains produce significant rates of beta-lactamase enzymes, which is extremely alarming. As carbapenem resistance is an alarming public health issue, early detection of the isolates and effective infection control measures are necessary to prevent their further spreading.

Background: Investigation of the gut-specific bacterial strains including lactobacilli is essential for understanding the bacterial etiology of constipation. Objective: This study aimed to compare the prevalence and quantity of intestinal lactobacilli in constipated children and healthy controls. Methods: Forty children fulfilling Rome IV criteria for functional constipation and 40 healthy controls were recruited. Fecal samples were analyzed using species-specific polymerase chain reaction followed by random amplified polymorphic DNA-PCR and quantitative real-time PCR. Results: Totally, seven different species of lactobacilli were detected. Out of 80 volunteers, 65 (81.3%) were culture and species-specific PCR positive from which 25 (38.46%) constipated children and 40 (61.54%) healthy subjects. The most prevalent species were L. paracasei 21 (32.3%) followed by L. plantarum 18 (27.7%) among both healthy and patient groups. Analysis of the RAPD dendrograms displayed that strains isolated from constipated and non-constipated children have similarity coefficients of more than 90%. The qPCR assays demonstrated constipated children had a lower amount of total lactobacilli population (per gram of feces) than healthy controls. Conclusion: Our findings showed that the mere existence of various species of Lactobacillus in the gut does not enough to prevent some gastrointestinal disorders such as functional constipation, and their quantity plays a more important role.

Carbapenem-resistant Escherichia coli has emerged as a major public health issue across the world. This study was aimed to determine the virulence content and phylogenetic groups of carbapenemase-producing E. coli isolates in southwest Iran. One hundred and fifty-two non-duplicate E. coli isolates were collected from various clinical samples. Antibiotic susceptibility and minimum inhibitory concentrations (MIC) were determined according to the Clinical and Laboratory Standards Institute (CLSI) guidelines by Kirby-Bauer disc diffusion and agar dilution methods. Phenotypic screening of carbapenemase enzymes was performed by modified Hodge test (MHT). Detection of carbapenemase genes, phylogenetic groups, and virulence-associated genes were also performed by the PCR assay. The highest and lowest resistance rates were observed against mezlocillin (70.4%) and doripenem (13.1%), respectively. Out of 28 isolates that were resistant to carbapenem antibiotics, 12 (7.9%) strains were phenotypically carbapenemase producers. The bla_OXA-48 was the predominant carbapenemase gene, detected in 58.3% of isolates, followed by bla_IMP (41.7%) and bla_NDM (8.3%). None of the isolates harbored bla_VIM and bla_KPC genes. Among the twelve carbapenemase-producing strains, urinary isolates were mostly classified into B2 (41.7%) and D (25%) phylogenetic groups, while other clinical isolates belonged to B1 (25%) and A (8.3%) groups. The frequency of virulence-associated genes was also investigated in all isolates and ranged from 6.6% for hly to 75% for fimA. The emergence of carbapenemase-producing strains is a growing concern to public health. Therefore, the proper implementation of monitoring programs is crucial for limiting their dissemination.

Background: The increasing prevalence of multidrug-resistant (MDR) Escherichia coli strains, especially extended-spectrum beta-lactamase (ESBL)-producing strains, has become a global health concern. This study was aimed to determine the frequency of bla _CTX-M, bla _TEM, and bla _SHV genes among E. coli isolates from urinary tract infection (UTI) and evaluate their antibiotic resistance pattern. Methods: Totally 98 E. coli isolates were recovered from urine samples of UTI-diagnosed patients. Antibiotic resistance and ESBL production were evaluated by disk diffusion and combined disk methods according to the Clinical Laboratory Standards Institute guidelines. The biofilm formation ability of isolates was assessed using the tube adherence method. ESBL-positive isolates were screened for bla _TEM, bla _CTX-M, and bla _SHV genes by polymerase chain reaction. Results: Among the examined isolates, 25 (25.5%) were detected as ESBL producers and harbored at least one of the studied genes. The bla _CTX-M was the predominant (44%) gene, followed by bla _TEM (24%) and bla _SHV (8%). The isolates revealed variable resistance levels to all antimicrobials, out of which 55.1% were conferred a high resistance rate to different antibiotic classes and considered MDR. Phenotypically, 42.85% of the isolates were biofilm formers, of which the majority (38%) formed moderate biofilms. Conclusions: This study showed that the ESBL-positive isolates were more resistant to some first-line antibiotics, and this highlights the necessity to control and monitor the prescribed antibiotics used for empirical treatment for UTI patients.