Efficacy of isolated bacteriophage against biofilm embedded colistin-resistant Acinetobacter baumannii

Abstract

Introduction: Acinetobacter baumannii is responsible for most nosocomial infections in hospitals. It can form biofilms and has a high degree of antibiotic resistance. Colistin is one of the last therapeutic options for the treatment of MDR infections. Recently, strains of this pathogen resistance to the colistin were reported increasingly. Therefore, alternative antibacterial methods, such as phage therapy, are being researched. This study aims to survey the efficacy of isolated Myoviridae bacteriophage against biofilm embedded colistinresistant Acinetobacter baumannii. Method: In this study, 15 isolates of bacteria were isolated, and their biofilm was measured using violet crystal staining, and their MIC was measured using the broth microdilution method. On the other hand, lytic phage was isolated and purified from wastewater. Finally, the effect of phage on bacteria was calculated using MTT staining method. Results: From 15 MDR A. baumannii clinical isolates, 26.6 were resistant to colistin, 80 were able to produce strong biofilm, and 20 have weak biofilm. The isolated lytic phage (IsfAB78) was able to reduce the biofilm by up to 87. Conclusions: This study showed that the isolated lytic phage impacted the biofilm of MDR A. baumannii. Phage IsfAB78 is the right candidate for this purpose.