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Escherichia coli is one of the most important pathogens causing bloodstream infections (BSIs) throughout the world. We sought to characterize the phylogroup classification, major human sequence types (STs), antimicrobial resistance, presence of selected antimicrobial resistance and virulence genes, and genetic diversity of E. coli isolated from patients with BSIs at the University Hospital in Iran. A total of 100 E. coli bloodstream isolates were collected between December 2020 and June 2022. This study used PCR to investigate phylogenetic groups (A, B1, B2, C, D, E, and F), four major STs (ST69, ST73, ST95, and ST131), antibiotic resistance genes (ARGs), virulence-associated genes (VAGs), and pathogenicity islands (PAIs). Antimicrobial susceptibility testing was done by disk diffusion method. Genetic diversity was analyzed by repetitive element sequence-based PCR (REP-PCR). The phylogenetic group B2 (32%) predominated, followed by phylogenetic group E (25%). ST131 (28%) was the most prevalent ST and the majority of these isolates (89.3%) were of serotype O25b. Most of E. coli isolates (75%) were categorized as multidrug resistant (MDR) with high rates of resistance (>55%) to ampicillin, trimethoprimsulfamethoxazole, ciprofloxacin, cefazolin, and ceftriaxone. The most frequent ARGs were blaTEM (66%), sul1 (57%), and sul2 (51%). The most prevalent VAGs and PAIs were fimH (type 1 fimbriae adhesin; 85%), aer (iucC) (aerobactin; 79%), traT (serum resistance; 77%), iutA (aerobactin siderophore receptor; 69%), and PAI IV536 (75%), respectively. The highest rate of ARGs and VAGs was observed in the ST131 isolates. REP-PCR analysis showed high diversity among the studied isolates. The high prevalence of MDR septicemic E. coli with different types of ARGs, VAGs and genotypes is an extremely worrisome sign of BSIs treatment and poses a major threat for hospitalized patients. Active surveillance, stringent prescribing policies, increasing the awareness of ARGs among clinicians and redefining the infection control measures are essential to curb the dissemination of these strains. [ABSTRACT FROM AUTHOR]

The epidemiology of Helicobacter pylori (H. pylori) infection in Ilam city, Western Iran, is not well understood. We conducted the current research to determine the seroprevalence of H. pylori infection in this city. A total of 1102 individuals (661 females and 441 males) older than12 years old were enrolled in the study. The bacterium was detected by the H. pylori stool antigen (HpSA) test. The rate of H. pylori positivity in the sample population was 54.4% (n=600). No statistically significant association was found between gender and the prevalence of H. pylori (P value = 0.21). The highest H. pylori prevalence was observed in the summer (17.6%, n= 194); however, no statistically significant relationship was detected between seasonal changes and the incidence of H. pylori infection (P value= 0.30). According to our results, it seems that the prevalence of H. pylori infection is high, especially in summer, in the population of Ilam city. This may become a major health concern in the area. [ABSTRACT FROM AUTHOR]

Introduction: Pseudomonas aeruginosa is a Gram-negative bacterium that considered as important opportunistic human pathogen. One of the mechanisms that help bacteria to tolerate survival in adverse conditions and resistance to antibiotics is biofilm formation through quorum sensing (QS) signals and toxin-antitoxin (TA) systems. QS and TA are two systems that have important roles in biofilm formation. QS is a global regulatory mechanism that enable bacteria to communicate with each other by production of auto inducers (AI) molecules in population. Because of importance biofilm formation in P. aeruginosa infections, here, we studied frequency of QS and TA genes among clinical isolates of P. aeruginosa with ability of biofilm formation. Materials and Methods: One hundred and forty clinical isolates of P. aeruginosa were collected from Tehran and Ilam hospitals. The isolates were identiied by biochemical tests. Biofilm formation was evaluated by microplate method. After DNA extraction by boiling method, the frequency of QS genes (lasIR, rhllR), and TA genes (mazEF, relBE, hipBA, ccdAB and mqsR) were analyzed by PCR. Results: Our results showed that maximum resistance is related to aztreonam (72.85%) antibiotic. Most of isolates were able to produce biofilm (87.15%) and the majority of them formed strong biofilm (56.42%). PCR results showed that frequency of mazEF, relBE, hipBA, ccdAB, mqsR, lasIR and rhlIR genes were 85.71, 100, 1.42, 100, 57.14, 93.57 and 83.57 percent, respectively. Conclusion: Clinical isolates of P. aeruginosa had high ability to form biofilm, and QS and TA system genes among these isolates were very high (except hipBA genes). There are significant correlation between biofilm for mation and present of QS and TA system genes. [ABSTRACT FROM AUTHOR]