Mehdi Mirzaii1, Sanaz Jamshidi2, Maryam Zamanzadeh2, Masoud Marashifard3, Seyed Ali Asghar Malek Hosseini3, Mehri Haeili4, Fariba Jahanbin2, Fariba Mansouri2, Davood Darban-Sarokhalil5, Seyed Sajjad Khoramrooz6. 1. Faculty of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran. 2. Department of Basic Sciences, Islamic Azad University, Yasooj Branch, Yasooj, Iran. 3. Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran. 4. Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran. 5. Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. 6. Medicinal Plants Research Center, Yasuj University of Medical Sciences, Yasuj, Iran; Department of Microbiology, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran. Electronic address: Khoramrooz@yums.ac.ir.
Abstract
OBJECTIVES: Fluoroquinolones (FQs) are recommended as the drugs of choice for the empirical treatment of urinary tract infections (UTIs). This study investigated the molecular determinants of FQ resistance in Escherichia coli and Klebsiella pneumoniae isolates in Iran. METHODS: A total of 364 clinical isolates of E. coli (n=144) and K. pneumoniae (n=220) were collected from patients with UTI. Susceptibility of the isolates to ciprofloxacin, levofloxacin, gatifloxacin and nalidixic acid was evaluated by disk diffusion. The presence of qnrA, qnrB and qnrS genes was assessed by PCR. Nucleotide sequences of the gyrA and parC genes were determined. RESULTS: Eighty-seven (60.4%) and 15 (6.8%) E. coli and K. pneumoniae isolates, respectively, were resistant to at least one of the tested FQs. Plasmid-mediated quinolone resistance (PMQR) genes were detected in 12.6% and 60.0% of FQ-resistant E. coli and K. pneumoniae, respectively. Whilst qnrB predominated in K. pneumoniae, qnrS was the most prevalent PMQR gene in E. coli. S83L (98.9%) and D87N (59.8%) were the most frequent mutations identified in GyrA of E. coli, and 55.2% (n=48) of FQ-resistant E. coli isolates had mutation in ParC harbouring S80I and E84V substitutions. The GyrAS83L substitution was found in only one FQ-resistant K. pneumoniae isolate. CONCLUSIONS: FQ resistance was much more common in E. coli isolates than in K. pneumoniae. Whilst mutations in the drug target-encoding genes gyrA and parC were the major mechanisms involved in FQ resistance in E. coli, PMQR determinants commonly mediated FQ resistance in K. pneumoniae.
OBJECTIVES:Fluoroquinolones (FQs) are recommended as the drugs of choice for the empirical treatment of urinary tract infections (UTIs). This study investigated the molecular determinants of FQ resistance in Escherichia coli and Klebsiella pneumoniae isolates in Iran. METHODS: A total of 364 clinical isolates of E. coli (n=144) and K. pneumoniae (n=220) were collected from patients with UTI. Susceptibility of the isolates to ciprofloxacin, levofloxacin, gatifloxacin and nalidixic acid was evaluated by disk diffusion. The presence of qnrA, qnrB and qnrS genes was assessed by PCR. Nucleotide sequences of the gyrA and parC genes were determined. RESULTS: Eighty-seven (60.4%) and 15 (6.8%) E. coli and K. pneumoniae isolates, respectively, were resistant to at least one of the tested FQs. Plasmid-mediated quinolone resistance (PMQR) genes were detected in 12.6% and 60.0% of FQ-resistant E. coli and K. pneumoniae, respectively. Whilst qnrB predominated in K. pneumoniae, qnrS was the most prevalent PMQR gene in E. coli. S83L (98.9%) and D87N (59.8%) were the most frequent mutations identified in GyrA of E. coli, and 55.2% (n=48) of FQ-resistant E. coli isolates had mutation in ParC harbouring S80I and E84V substitutions. The GyrAS83L substitution was found in only one FQ-resistant K. pneumoniae isolate. CONCLUSIONS: FQ resistance was much more common in E. coli isolates than in K. pneumoniae. Whilst mutations in the drug target-encoding genes gyrA and parC were the major mechanisms involved in FQ resistance in E. coli, PMQR determinants commonly mediated FQ resistance in K. pneumoniae.
Authors: Sawsan Mohammed Kareem; Israa M S Al-Kadmy; Saba S Kazaal; Alaa N Mohammed Ali; Sarah Naji Aziz; Rabab R Makharita; Abdelazeem M Algammal; Salim Al-Rejaie; Tapan Behl; Gaber El-Saber Batiha; Mohamed A El-Mokhtar; Helal F Hetta Journal: Infect Drug Resist Date: 2021-02-12 Impact factor: 4.003
Authors: Mohammad Moein Vakilzadeh; Amirhossein Heidari; Ali Mehri; Matin Shirazinia; Fereshte Sheybani; Ehsan Aryan; HamidReza Naderi; Mona Najaf Najafi; Marjan Varzandeh Journal: J Environ Public Health Date: 2020-10-05