Efficacy of Acinetobacter baumannii bacteriophage cocktail on Acinetobacter baumannii growth

Abstract

Acinetobacter baumannii is an opportunistic pathogen which is a major cause of nosocomial infection. Bacteriophages are bacterial viruses that are used as alternative agents in the treatment of multidrug-resistant bacterial infections. In this research, our purpose was to investigate the efficacy of a cocktail of five bacteriophages. Ten (10) bacteriophage isolates were determined for the host range analysis and five bacteriophages, OABP-02, OABP-19, OABP-29, OABP-39 and OABP-44 that showed broad host range (36.9-64.6 %) were selected for the preparation of the bacteriophage cocktail. Transmission electron microscopy revealed OABP-02 and OABP-44 belonged to family Myoviridae and OABP-19, OABP-29, OABP-39 belonged to family Podoviridae. The bacteriophage cocktail was tested for its efficacy on growth inhibition against 44 A. baumannii clinical isolates using the colorimetric microtiter plate method. The results of the growth inhibition assay of the bacteriophage cocktail showed that the growth inhibition against A. baumannii ranged from 45.1- 96%. High efficacy of the bacteriophage cocktail was found against the A. baumannii strains that can be infected by the five bacteriophages (>77%). Our study demonstrates high efficacy of the bacteriophage cocktail on inhibiting the growth of A. baumannii. The bacteriophage cocktail is a valuable alternative agent for controlling the multi- drug resistant A. baumannii in hospitals. Key words: Bacteriophage, Acinetobacter baumannii, growth inhibition, host range.