Detection of IS903, IS26 and ISEcp1 Elements in CTX-M-Producing Klebsiella pneumoniae and Escherichia coli Isolates From Patients with Leukemia in Iran

The ability of extended spectrum beta-lactamases (ESBLs) production is one of the main mechanisms for the emergence of antibiotic resistance in Escherichia coli and Klebsiella pneumoniae. The aim of this study was to evaluate the occurrence of IS903, IS26, and ISEcp1 insertion elements among the CTX-M-producing K. pneumoniae and E. coli isolates from patients with leukemia in Tehran. Eighty E. coli and K. pneumoniae isolates were recovered from patients admitted to hospitals of Tehran. Antibiotic susceptibility tests were performed by Kirby-Bauer disc diffusion and broth microdilution methods. Detection of ESBL producers was evaluated by phenotypic confirmatory test. The presence of IS903, IS26, and ISEcp1 insertion elements in CTX-M-positive E. coli and K. pneumoniae isolates was investigated by PCR-sequencing methods. The rate of resistance of 80 E. coli and K. pneumoniae isolates against the nine antibiotics was as follows: 100% to ampicillin, 15% to amikacin, 51% to ciprofloxacin, 30% to gentamicin, 58% to ceftriaxone, 10% to imipenem, 63% to cefotaxime, 51% to levofloxacin, and 55% to ceftazidime. Using phenotypic confirmatory test revealed that 51 (63.75%) isolates were ESBL producers. The prevalence of CTX-M-1, CTX-M-2, CTX-M-9, CTX-M-8, and CTX-M-25 genes was 87.5%, 13.75%, 23.75%, 10%, and 0%, respectively. IS903, IS26, and ISEcp1 elements were detected in 93.75%, 71.25%, and 100% of the isolates, respectively. This study indicates that the high prevalence of antibiotic resistance, IS and CTX-M-producing E. coli, and K. pneumoniae isolates could be a major concern and highlights the need for infection control measures.