Co-production of ESBL and OXA-48 in 3 of 67 isolates, with a unique NDM-1/OXA-48 co-producing strain from a pediatric ALL patient: a case series

Abstract

Abstract Background Antibiotic resistance poses a major challenge in treating bloodstream infections (BSI) from Escherichia coli in patients with leukemia. Imipenem, a carbapenem antibiotic and, is considered an effective option for treating bloodstream infections in patients with leukemia. Carbapenemase-producing bacteria are increasingly reported worldwide and are considered a significant concern for public health services. E. coli is the main pathogen in patients with hematological malignancies. Leukemic patients are at high risk of developing bloodstream infections (BSI), which is one of the most important side effects of chemotherapy. The aim of this study was to report for the first time an E. coli strain co-producing bla OXA-48 and bla NDM-1 carbapenemases isolated from a BSI of an Iranian leukemia patient and its characteristics. Case presentation Three bla OXA-48 -producing E. coli strains were isolated from three Iranian leukemia patients (two boys, aged 3 and 5 years, with acute lymphoblastic leukemia and one 26-year-old male patient with chronic myeloid leukemia). The patients were from Gilak, Talesh, and Fars ethnicities. These patients had fever and bacteremia caused by E. coli . Antibiotic susceptibility testing was conducted using both the broth dilution method and the disk diffusion method. Carbapenemase production in the isolates was detected via a modified Hodge test. In addition, PCR was used to screen for the presence of the bla NDM-1 and bla OXA - 48 genes that encode carbapenemases. Sixty-seven E. coli strains associated with bloodstream infections in leukemia patients were evaluated from January 2021 to April 2022). Among the 67 isolates, three isolates (4.4%) produced bla OXA-48 and all three isolates produced ESBL. Only one isolate showing co-expression of the bla NDM-1 and bla OXA - 48 genes was isolated from a 3-year-old male patient with acute lymphoblastic leukemia (ALL). This strain was resistant to ampicillin, ceftriaxone, aztreonam, cefepime, cefixime, ceftazidime, imipenem, levofloxacin, and amoxicillin/clavulanic acid. Conclusions The co-expression of bla OXA - 48 and bla NDM-1 genes in E. coli strains from bloodstream infections in leukemia patients is concerning, as it increases antibiotic resistance and complicates treatment options.