Co-occurrence of Quinolone Resistance (Qnr) Genes and ESBL (CTX-M) in Uropathogenic Klebsiella pneumoniae and Escherichia coli from Patients in Onitsha, Nigeria
Uchechukwu G. Mgbedo
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Ugochukwu M. Okezie
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Chidimma R. Chukwunwejim
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Ijeoma N. Ebenebe
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Nzube F. Ekpunobi *
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Ezinne Janefrances umeh
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, University of Port Harcourt, Choba, Rivers State, Nigeria.
Sandra C. Okoye
Department of Biological Sciences, College of Liberal Arts and Sciences, Eastern Illinois University, USA.
Lydia C. Okoye
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Moses N. Ikegbunam
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Malachy C. Ugwu
Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Escherichia coli and Klebsiella pneumoniae are leading uropathogens, with rising resistance to fluoroquinolones and β-lactams posing major treatment challenges. The co-occurrence of plasmid-mediated quinolone resistance (PMQR) genes and extended-spectrum β-lactamase (ESBL) determinants further complicates therapy. A cross-sectional study was conducted on urine specimens collected from patients with suspected urinary tract infections (UTIs) in Onitsha, Nigeria. Isolates were identified by standard microbiological and biochemical procedures. Antibiotic susceptibility study was assessed using the Kirby–Bauer disk diffusion method and interpreted according to CLSI guidelines. Phenotypic ESBL detection was performed by the double-disk synergy test, while PCR was employed to detect qnrA, qnrB, and CTX-M genes. Among 297 urine samples, 158 (53.2%) yielded significant bacterial growth, predominantly K. pneumoniae (51.9%) and E. coli (48.1%). High resistance rates were observed to β-lactams and fluoroquinolones, with over 60% of isolates resistant to cefotaxime and ciprofloxacin. Phenotypic ESBL production was absent, but PCR revealed CTX-M in 6.6% and qnrA/qnrB in 36.7% of isolates. The high prevalence of multidrug resistance and plasmid-mediated quinolone resistance among E. coli and K. pneumoniae in Onitsha highlights the urgent need for routine molecular surveillance. Incorporating genotypic screening into resistance monitoring programs is critical for guiding effective antimicrobial stewardship and preserving therapeutic options.
Keywords: Urinary tract infections, Escherichia coli, Klebsiella pneumonia, quinolone resistance, ESBL, qnr, CTX-M