Antimicrobial susceptibility pattern of newer beta lactam-beta lactamase inhibitor agents on the carbapenem resistant and sensitive strains of Enterobacterales and Pseudomonas aeruginosa

Abstract

The rise of antimicrobial resistance has become a global threat in the recent years. With the rise in multidrug resistant organisms (MDRO), particularly the Carbapenem resistant organisms “difficult to treat” infections there is an urgent need for newer antibiotics. There are limited therapeutic options currently available, of which Ceftazidime avibactam (CZA) is a novel Beta lactam/ Beta lactamase inhibitor (BL/BLI) combination antibiotic. Avibactam is a non BL/BLI that binds reversibly to beta lactamase. The study aims to find the susceptibility of the novel Beta lactam- Beta lactamase combination drugs in carbapenem resistant & carbapenem sensitive isolates.1. To compare the susceptibility profile of CZA in Carbapenem resistant & carbapenem sensitive isolates of & ; 2. To compare the sensitivity of CZA with other group of antibiotics. This is a retrospective observational study from January 2022 to November 2023 done in the Department of Microbiology, Medanta Hospital, Lucknow. All the bacterial culture samples received during this period were subjected to routine identification and antibiotic susceptibility test on Vitek2 compact automated system. and isolates are included in the study group.: Of the Carbapenem Resistant isolates, , spp., spp. were 26.09% , 68.6% and 46.4% respectively. Amongst the carbapenem resistant(CR) isolates, CR (18.6%) is most susceptible to CZA than 9% CR & 3.2% CR . Of the Carbapanem sensitive isolates, sensitivity to CZA in (90.5%), (92.1%) & 87% in appeared to be much better than the other BL-BLI’s agents. The study suggests that CZA can be used as carbapenem sparing agent only in carbapenem sensitive pathogens. Also with the rise in resistance to the novel drug, it should be used judiciously and not as empiric therapy or an alternative to carbapenems. It may be useful in NDM carbapenemase producers if used synergistically with Aztreonam.