RESUMEN
BACKGROUND: Carbapenemase-producing Enterobacterales (CPE) show rapid global dissemination and pose a significant therapeutic challenge. This study aimed to characterize carbapenemase-producing Klebsiella spp. and Escherichia coli (E. coli) phenotypically and genotypically and evaluate the effect of ceftazidime/ avibactam plus aztreonam combination. METHODS: A total of 219 Klebsiella species and 390 E. coli strains were isolated from clinical samples, in which 80 Klebsiella spp. and 20 E coli isolates were resistant to tested carbapenems (imipenem, ertapenem, meropenem) by disk diffusion/broth dilution method and Vitek-2 compact system. MASTDISCS Combi Carba plus discs and real time PCR were used to determine type of carbapenemase phenotypically and genotypically, respectively. Interestingly, the synergistic effect between ceftazidime-avibactam (E-test) and aztreonam (disc) was tested against the CPE isolates. RESULTS: Out of the carbapenem-resistant isolates, 76.25% Klebsiella spp. isolates were extensively drug-resistant (XDR) while 18.75% were pan drug-resistant (PDR), and 5% were multidrug-resistant (MDR). Regarding E. coli, 5% were PDR, 20% were MDR and 75% were XDR. More than one carbapenemase gene was detected in 99% of the isolates. In comparison between MAST-Carba plus discs and PCR results, sensitivity and specificity were (85.42-97.92%) in Klebsiella spp., and (69.64-100%) in E. coli, respectively. Moreover, a strong association was detected between both test results among Klebsiella spp. (p < 0.001) and E. coli (p = 0.012) isolates. Finally, ceftazidime-avibactam and aztreonam combination showed a synergistic effect in 98.8% of Klebsiella spp. and 95% of E coli. All 16 PDR isolates showed synergy. CONCLUSION: This synergistic effect spots the light on new therapeutics for XDR and PDR CPE.
Asunto(s)
Aztreonam , Ceftazidima , Humanos , Ceftazidima/farmacología , Ceftazidima/uso terapéutico , Aztreonam/farmacología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Carbapenémicos/farmacología , Escherichia coli/genética , Combinación de Medicamentos , beta-Lactamasas/genética , Klebsiella/genética , Pruebas de Sensibilidad Microbiana , Klebsiella pneumoniaeRESUMEN
New Delhi metallo-beta-lactamase (NDM)-producing Klebsiella pneumoniae is increasingly reported worldwide. Clinicians face significant challenges in the treatment of this multidrug-resistant bacterium. The combination of ceftazidime/avibactam (CAZ/AVI) and aztreonam (ATM) is currently probably the most effective strategy for the treatment of such infection. We described a patient diagnosed with NK/T cell lymphoma who underwent autologous hematopoietic stem cell transplantation (ASCT) in the hematology department. The patient developed severe infection after ASCT. Blood and stool cultures showed carbapenem-resistant K. pneumoniae. Blood sample was detected as NDM-producing K. pneumoniae. We successfully treated this infection with CAZ/AVI and ATM.