Assessing Antimicrobial Stewardship: A Survey of Distribution Practices in Dispensaries in Ghana

Introduction: Ceftazidime-avibactam (CAZ-AVI) is an innovative combination of the non--lactam -lactamase inhibitor avibactam and the extended-spectrum ceftazidime.This combination is effective in treating infections resulted frommultidrug resistant (MDR) Gram-negative bacteria.Therefore, the present study was done to determine the efficacy of CAZ-AVI in carbapenem-resistant against non-fermenters Gram-negative bacteria.Materials and Methods: The present study was done at a tertiary care hospital in Lahore, Pakistan over the period of 2 years.Different clinical samples were processed according to standard microbiological techniques.Confirmation of bacterial isolates was done by different biochemical tests.Antimicrobial sensitivity testing was done onVitek 2 automated system.CAZ-AVI sensitivity testing was performed for carbapenem-resistant isolates on Meuller Hamilton (MH) agar according to Clinical and Laboratory Standard institute (CLSI) guidelines.Results: CAZ-AVI was 100% sensitive in carbapenem sensitive isolates.Among non-fermenters, highest resistance against CAZ-AVI was found in Acinetobacterspp.(90.8%) while 75% resistance was observed in P. aeruginosa isolates.Maximum number of isolates were collected from wound (35%) followed by pus (16.8%).Discussion: In our study, 66.7% resistance was observed against CAZ-AVI among the isolates of carbapenem resistant P. aeruginosa while only 33.3% isolates were found to be susceptible.Similar to our results, reduced susceptibility rate of P. aeruginosa was also reported from several other countries.Lowest susceptibility rates were observed in Romania which was22.2%, 23.1% in Latvia/Lituania and 39.4% susceptibility rate was reported from Ukraine [19].These results were in accordance with our findings.Contradiction to our results, a study conducted in 2018, reported only 2.9% resistance against CAZ-AVI among P. aeruginosa isolates but the isolates were carbapenem sensitive [20].However, several other studies reported higher resistance rates of 50.9% and 48.2% especially when the isolates were extensively drug resistant or resistant to carbapenems respectively [21].Moreover, it was also found that MBL-positive isolates also showed > 95% resistance rate against ceftazidime-avibactam[22, 23].Our study reported 74.7% resistance in A. baumanii against CAZ-AVI, consistent to our results, a study conducted by Sader et al in 2015 reported 68.8% resistance of CAZ-AVI in Acinetobacter isolates.Higher resistance was observed in isolates collected from intensive care units (ICUs) which was 73.6% [24].Moreover, MDR and blaOXA-51 gene carrying isolates were found to be completely resistant against .Another study conducted on cancer patients reported 57.1% resistance of Acinetobacter spp.against CAZ-AVI.Likewise, several other antimicrobial agents were found to be of moderate to poor efficacy against Acinetobacter spp [26].Conclusion: CAZ-AVI was considered a good option for the treatment of infections caused by XDR and MDR Gram negative rods.However, its effectiveness against non-fermenters is less as compared to othermembers of Gram-negative bacteria.Moreover, the increasing resistance rate against CAZ-AVI associated with CR needs to be noted.