Assessment of In vitro Activities of Ceftaroline, Ceftazidime/ avibactam and Colistin against different Gram Negative and Gram Positive Isolates

Abstract

Background: Multidrug resistance organisms (MDRO) emergence is recognized as a serious threat to worldwide health and welfare. Infections with MDRO are associated with longer hospitalization periods, relatively high infection-related death, and greater health expenditures. The appearance of carbapenems resistant Enterobacteriaceae (CRE) and vancomycin resistant Staph aureus (VRS) makes the condition worse, since carbapenems and vancomycin were the drug of choice in treatment of MDR Enterobacteriaceae and methicillin resistant Staph aureus (MRSA). Accordingly the evaluation of new drugs used as substitution to other resistant antibiotics became an urgent need worldwide. Objective: The objective of this research is to assess the in vitro activity of ceftaroline, ceftazidime-avibactam and colistin activity against various complicated infections with resistant bacteria. Methodology: Antibiotic susceptibility of all clinical isolates was performed by the disk diffusion method, and results in interpretation were performed according to CLSI guidelines ( 2019) Results: concerning Gram-negative bacteria, ceftazidime-avibactam and colistin showed high susceptibility (>85%) and (100%) respectively against Pseudomonas aeruginosa and Enterobacteriaceae, with enhanced antibacterial activity due to the inclusion of avibactam to ceftazidime drug. Ceftaroline demonstrated susceptibility ranged from (53% -75.8%) against Gram-negative bacteria and (> 75%) against Gram-positive bacteria including MRSA. Conclusion: results showed acceptable susceptibility of both Gram negative and Gram positive isolates against tested antibiotics, however further investigations on increased number of isolates are required.