High ceftazidime-avibactam resistance rate in carbapenem-resistant gram-negative organisms in Pakistan's pediatric population.

Abstract

Objective: This study investigates resistance to a newly available drug Ceftazidime-Avibactam (CAZ-AVI) in carbapenem-resistant gram-negative organisms (GNOs) in the Pakistan's pediatric population.

Methods: This was a prospective study carried out in the Department of Microbiology at The Children's Hospital, Lahore from May 2023 to July 2023. A sum of 7491 specimens of blood, cerebrospinal fluid (CSF), urine, pus, nasal swabs, central venous catheter (CVP) tips and tracheal secretion were analyzed for presence of carbapenem resistant gram-negative organisms which were then further screened for CAZ-AVI resistance. Analytical profile index and Kirby-Bauer disk diffusion methods were used for the identification of organisms.

Results: A total of 217(n) carbapenem-resistant bacterial species, including 165(n) Klebsiella sp., 32(n) Pseudomonas sp., and 20(n) Escherichia coli (E. coli) strains, were tested for sensitivity against CAZ-AVI. Approximately, 70.5% (153 out of 217) of carbapenem-resistant bacteria exhibited resistance to CAZ-AVI. Among the resistant bacterial species, 80% (122/153) were Klebsiella sp., 14% (21/153) were Pseudomonas sp., and 6% (10/153) were E. coli. These findings suggest pre-existing resistance mechanisms may be responsible for exhibiting resistance to CAZ-AVI in these organisms.

Conclusion: Taking into account the results of this study, which depicted high resistance rates to CAZ-AVI among carbapenem resistant GNOs, and the high cost of this drug, it is suggested that a cautious selection for its use as monotherapy in sepsis and other infections should be made. It should be made mandatory to check the resistance to CAZ-AVI before its empiric use. The findings of the study also emphasize the challenges of combating new drug resistance and further research to adapt treatment strategies to the evolving antimicrobial resistance in the region.