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Showing 2 results for Shafighi
Resistance investigation of uropathogenic Escherichia coli strains isolated from urinary tract infections in the north of Iran
Zahra Askari, Zeynab Mirzapour, Tooba Shafighi, Reyhaneh Ghorbanpour,
Volume 19, Issue 1 (Jan-Feb 2025)
Abstract
Background: Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) represent a significant global health concern. Virulence factors (VFs) expressed by UPEC strains play a crucial role in promoting bacterial pathogenicity within the urinary tract. Effective treatment of these infections is frequently complicated by the high prevalence of antimicrobial resistance exhibited by Escherichia coli. The objective of this study was to investigate the VFs and antibiotic susceptibility profiles of UPEC strains isolated in the northern region of Iran.
Methods: One hundred and five urine specimens were collected from female patients diagnosed with UTIs in Rasht, located in the north of Iran. These samples underwent culturing on both Eosin Methylene Blue (EMB) agar and MacConkey agar. Following a 24-hour incubation period at 37°C, pure bacterial isolates were identified through Gram staining and a battery of standard biochemical assays. The prevalence of six VF genes - papC, sfa/foc, fimH, afa, ibeA, and neuC - within UPEC strains was determined utilizing polymerase chain reaction (PCR) and subsequently confirmed via direct sequencing. Antibiotic susceptibility testing (AST) was conducted using the disk diffusion method, adhering to the guidelines established by the Clinical and Laboratory Standards Institute (CLSI M02).
Results: The study identified 65.71% of the isolates as Escherichia coli. Among the virulence genes examined, fimH exhibited the highest prevalence (100%), while afa was the least frequent (1.44%). Antibiotic resistance analysis revealed the highest rate against Cefazolin (66.66%) and the lowest against Gentamicin (24.63%). Notably, the prevalence of multi-drug resistance (MDR) was determined to be 73.91%.
Conclusion: This study underscored the significance of localized surveillance of UPEC isolates. This emphasis stems from the pathogen's considerable capacity for genetic mutation, coupled with the influence of environmental variables and individual patient characteristics. Understanding these dynamic factors at a local level is crucial for formulating the most effective strategies to combat UTIs.

Metallo-β-lactamase detection in imipenem-resistant Acinetobacter spp. and pseudomonas aeruginosa: A combined phenotypic and molecular study
Zahra Nasirzadeh , Seyedeh Tooba Shafighi ,
Volume 20, Issue 3 (7-2026)
Abstract
Background: The incidence of healthcare-associated infections (HAIs) is increasing rapidly, primarily driven by multidrug-resistant Gram-negative pathogens, notably Pseudomonas aeruginosa and Acinetobacter spp. Metallo-beta-lactamases (MBLs), including IMP and VIM types, are frequently produced by these organisms and contribute to therapeutic challenges through gene dissemination and prolonged colonization in clinical settings. This study, conducted in Rasht, Iran, aimed to evaluate phenotypic resistance and MBL production in imipenem-resistant clinical isolates of P. aeruginosa and Acinetobacter.
Methods: In this descriptive cross-sectional study, 52 Acinetobacter and 25 P. aeruginosa isolates were obtained from healthcare facilities in Rasht. Species identification was confirmed using standard biochemical assays. Antimicrobial susceptibility was assessed using the disk diffusion method in accordance with CLSI recommendations. MBL-producing isolates were screened using the imipenem-EDTA combined disk test. Genomic DNA was extracted with a commercial kit, followed by PCR amplification to detect the blaIMP and blaVIM genes.
Results: According to the findings of this study, the highest percentage of resistance in Acinetobacter was observed against cefotaxime at 94.23%, and in P. aeruginosa against ceftazidime at 84%. Among the isolates not susceptible to imipenem, 18 (40%) Acinetobacter and 2 (15.38%) P. aeruginosa isolates were identified as MBL producers by the combined disk method. Both P. aeruginosa and Acinetobacter isolates demonstrated high resistance to ceftazidime. The blaIMP and blaVIM genes were detected in 7 (13.46%) and 11 (21.15%) Acinetobacter isolates, respectively, and in 8 (32%) and 5 (20%) P. aeruginosa isolates, respectively.
Conclusion: Early detection of Acinetobacter and P. aeruginosa strains producing metallo-β-lactamases is key to guiding effective clinical treatment and improving patient outcomes. These results suggest that the blaIMP and blaVIM genes play important roles in antibiotic resistance and may potentially influence the virulence of Acinetobacter species and P. aeruginosa in the region.

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