Identification of plasmid encoded qepA efflux pump gene in Citrobacter freundii isolates from a renowned hospital, Bangladesh
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Abstract
Background and Objectives: The emergence of plasmid-mediated resistance to quinolones is a growing global threat that complicates the control of multidrug-resistance (MDR) in Enterobacteriaceae. This study was conducted to determine the frequency of the qepA gene and its association with antibiotic resistance in Citrobacter freundii isolates from various clinical samples.
Materials and Methods: To conduct this study, a total of 27 C. freundii isolates collected from urine, endotracheal aspirates, sputum, blood, and stool samples were identified using standard biochemical tests and culture methods. Their susceptibility to ciprofloxacin was determined via the MIC agar dilution method. Specific primers were used to confirm C. freundii and detect the qepA gene by PCR. Subsequently, DNA sequencing was performed using a capillary method, and the sequences were compared to similar genes available in GenBank.
Results: Among the isolated C. freundii strains, 77.78% were resistant to ciprofloxacin. Of these resistant isolates, 9.52% were found to harbor the qepA gene. Sequencing and BLAST analysis confirmed a 99% similarity to the Citrobacter koseri strain CD4359 plasmid pCD4359 (GenBank accession number KR259132.1) and revealed a point mutation at position 58.
Conclusion: This finding highlights the distribution of the qepA gene in clinical isolates, emphasizing the need for continuous molecular surveillance to screen PMQR determinants and to implement effective antimicrobial stewardship strategies.
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20. Silva-Sánchez J, Cruz-Trujillo E, Barrios H, Reyna-Flores F, Sánchez-Pérez A, Bacterial Resistance Consortium, et al. Characterization of plasmid-mediated quinolone resistance (PMQR) genes in extended-spectrum β-lactamase-producing Enterobacteriaceae pediatric clinical isolates in Mexico. PLoS One 2013; 8(10): e77968.
21. Vien Ie LT, Minh NN, Thuong TC, Khuong HD, Nga TV, Thompson C, et al. The co-selection of fluoroquinolone resistance genes in the gut flora of Vietnamese children. PLoS One 2012; 7(8): e42919.
22. Biez L, Bonnin RA, Emeraud C, Birer A, Jousset AB, Naas T, et al. Nationwide molecular epidemiology of carbapenemase-producing Citrobacter spp. in France in 2019 and 2020. mSphere 2023; 8(6): e0036623.
23. Tewawong N, Kowaboot S, Lektrakul W, Supcharoengoon U, Watanagul N, Pitaksajjakul P. Mechanisms of fluoroquinolone resistance among Escherichia coli isolates from urinary tract infections in Thailand. PLoS One 2025; 20(5): e0325175.
24. Chen PL, Wu CJ, Chang CM, Lee HC, Lee NY, Shih HI, et al. Extraintestinal focal infections in adults with Salmonella enterica serotype Choleraesuis bacteremia. J Microbiol Immunol Infect 2007; 40: 240-247.
25. Kariuki K, Diakhate MM, Musembi S, Tornberg-Belanger SN, Rwigi D, Mutuma T, et al. Plasmid-mediated quinolone resistance genes detected in ciprofloxacin non-susceptible Escherichia coli and Klebsiella isolated from children under five years at hospital discharge, Kenya. BMC Microbiol 2023; 23: 129.
26. Pasom W, Chanawong A, Lulitanond A, Wilailuckana C, Kenprom S, Puang-Ngern P. Plasmid-mediated quinolone resistance genes, aac (6′)-Ib-cr, qnrS, qnrB, and qnrA, in urinary isolates of Escherichia coli and Klebsiella pneumoniae at a teaching hospital, Thailand. Jpn J Infect Dis 2013; 66: 428-432.
27. Ayobola ED, Oscar WO, Ejovwokoghene EF. Occurrence of plasmid mediated fluoroquinolone resistance genes amongst enteric bacteria isolated from human and animal sources in Delta State, Nigeria. AIMS Microbiol 2021; 7: 75-95.
28. Ogbolu DO, Alli AO, Anorue MC, Daini OA, Oluwadun A. Distribution of plasmid-mediated quinolone resistance in Gram-negative bacteria from a tertiary hospital in Nigeria. Indian J Pathol Microbiol 2016; 59: 322-326.
2. Tenaillon O, Skurnik D, Picard B, Denamur E. The population genetics of commensal Escherichia coli. Nat Rev Microbiol 2010; 8: 207-217.
3. Liu X, Huang Y, Xu X, Zhao Y, Sun Q, Zhang Z, et al. Complete genome sequence of multidrug-resistant Citrobacter freundii strain P10159, isolated from urine samples from a patient with esophageal carcinoma. Genome Announc 2016; 4(1): e01754-15.
4. Samonis G, Karageorgopoulos DE, Kofteridis DP, Matthaiou DK, Sidiropoulou V, Maraki S, et al. Citrobacter infections in a general hospital: characteristics and outcomes. Eur J Clin Microbiol Infect Dis 2009; 28: 61-68.
5. Ranjan KP, Ranjan N. Citrobacter: An emerging health care associated urinary pathogen. Urol Ann 2013; 5: 313-314.
6. Majewski P, Wieczorek P, Łapuć I, Ojdana D, Sieńko A, Sacha P, et al. Emergence of a multidrug-resistant Citrobacter freundii ST8 harboring an unusual VIM-4 gene cassette in Poland. Int J Infect Dis 2017; 61: 70-73.
7. Pham TDM, Ziora ZM, Blaskovich MAT. Quinolone antibiotics. Quinolone antibiotics. Medchemcomm 2019; 10: 1719-1739.
8. Biswas M, Roy DN, Tajmim A, Rajib SS, Hossain M, Farzana F, et al. Prescription antibiotics for outpatients in Bangladesh: a cross-sectional health survey conducted in three cities. Ann Clin Microbiol Antimicrob 2014; 13: 15.
9. Aldred KJ, Kerns RJ, Osheroff N. Mechanism of quinolone action and resistance. Biochemistry 2014; 53: 1565-1574.
10. Bisacchi GS. Origins of the quinolone class of antibacterials: an expanded “discovery story” miniperspective. J Med Chem 2015; 58: 4874-4882.
11. Dalhoff A. Global fluoroquinolone resistance epidemiology and implications for clinical use. Interdiscip Perspect Infect Dis 2012; 2012: 976273.
12. Li XZ, Nikaido H. Efflux-mediated drug resistance in bacteria: an update. Drugs 2009; 69: 1555-1623.
13. Yamane K, Wachino JI, Suzuki S, Kimura K, Shibata N, Kato H, et al. New plasmid-mediated fluoroquinolone efflux pump, qepA, found in an Escherichia coli clinical isolate. Antimicrob Agents Chemother 2007; 51: 3354-3360.
14. Andrews JM. Determination of minimum inhibitory concentrations. J Antimicrob Chemother 2001:48:5-16.
15. Hombach M, Maurer FP, Pfiffner T, Böttger EC, Furrer R. Standardization of operator-dependent variables affecting precision and accuracy of the disk diffusion method for antibiotic susceptibility testing. J Clin Microbiol 2015; 53: 3864-3869.
16. Adamo R, Margarit I. Fighting antibiotic-resistant Klebsiella pneumoniae with “sweet” immune targets. mBio 2018; 9(3): e00874-18.
17. Thapa B, Adhikari P, Mahat K, Chhetri MR, Joshi LN. Multidrug-resistant nosocomial Citrobacter in a hospital in Kathmandu. Nepal Med Coll J 2009; 11: 195-199.
18. Hariharan P, Bharani T, Franklyne JS, Biswas P, Solanki SS, Paul-Satyaseela M. Antibiotic susceptibility pattern of Enterobacteriaceae and non-fermenter Gram-negative clinical isolates of microbial resource orchid. J Nat Sci Biol Med 2015; 6: 198-201.
19. Garvey MI, Baylay AJ, Wong RL, Piddock LJ. Overexpression of patA and patB, which encode ABC transporters, is associated with fluoroquinolone resistance in clinical isolates of Streptococcus pneumoniae. Antimicrob Agents Chemother 2011; 55: 190-196.
20. Silva-Sánchez J, Cruz-Trujillo E, Barrios H, Reyna-Flores F, Sánchez-Pérez A, Bacterial Resistance Consortium, et al. Characterization of plasmid-mediated quinolone resistance (PMQR) genes in extended-spectrum β-lactamase-producing Enterobacteriaceae pediatric clinical isolates in Mexico. PLoS One 2013; 8(10): e77968.
21. Vien Ie LT, Minh NN, Thuong TC, Khuong HD, Nga TV, Thompson C, et al. The co-selection of fluoroquinolone resistance genes in the gut flora of Vietnamese children. PLoS One 2012; 7(8): e42919.
22. Biez L, Bonnin RA, Emeraud C, Birer A, Jousset AB, Naas T, et al. Nationwide molecular epidemiology of carbapenemase-producing Citrobacter spp. in France in 2019 and 2020. mSphere 2023; 8(6): e0036623.
23. Tewawong N, Kowaboot S, Lektrakul W, Supcharoengoon U, Watanagul N, Pitaksajjakul P. Mechanisms of fluoroquinolone resistance among Escherichia coli isolates from urinary tract infections in Thailand. PLoS One 2025; 20(5): e0325175.
24. Chen PL, Wu CJ, Chang CM, Lee HC, Lee NY, Shih HI, et al. Extraintestinal focal infections in adults with Salmonella enterica serotype Choleraesuis bacteremia. J Microbiol Immunol Infect 2007; 40: 240-247.
25. Kariuki K, Diakhate MM, Musembi S, Tornberg-Belanger SN, Rwigi D, Mutuma T, et al. Plasmid-mediated quinolone resistance genes detected in ciprofloxacin non-susceptible Escherichia coli and Klebsiella isolated from children under five years at hospital discharge, Kenya. BMC Microbiol 2023; 23: 129.
26. Pasom W, Chanawong A, Lulitanond A, Wilailuckana C, Kenprom S, Puang-Ngern P. Plasmid-mediated quinolone resistance genes, aac (6′)-Ib-cr, qnrS, qnrB, and qnrA, in urinary isolates of Escherichia coli and Klebsiella pneumoniae at a teaching hospital, Thailand. Jpn J Infect Dis 2013; 66: 428-432.
27. Ayobola ED, Oscar WO, Ejovwokoghene EF. Occurrence of plasmid mediated fluoroquinolone resistance genes amongst enteric bacteria isolated from human and animal sources in Delta State, Nigeria. AIMS Microbiol 2021; 7: 75-95.
28. Ogbolu DO, Alli AO, Anorue MC, Daini OA, Oluwadun A. Distribution of plasmid-mediated quinolone resistance in Gram-negative bacteria from a tertiary hospital in Nigeria. Indian J Pathol Microbiol 2016; 59: 322-326.
| Files | ||
| Issue | Vol 17 No 6 (2025) | |
| Section | Original Article(s) | |
| DOI | https://doi.org/10.18502/ijm.v17i6.20368 | |
| Keywords | ||
| Bangladesh Citrobacter freundii Efflux pump Primer Point mutation | ||
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How to Cite
1.
Rahman A, Ansary Nabonee M, Zannat Dola N, Shamsuzzaman S. Identification of plasmid encoded qepA efflux pump gene in Citrobacter freundii isolates from a renowned hospital, Bangladesh. Iran J Microbiol. 2025;17(6):998-1004.
