Isolation and characterization of Acinetobacter phage vAbaIN10 active against Carbapenem Resistant Acinetobacter baumannii (CRAB) isolates from healthcare-associated infections in Dakar, Senegal.
Background: Acinetobacter baumannii, particulary Carbapenem-resistant strains (CRAB), stands as a primary concern in the battle against escalating antibiotic resistance, identified as a top priority pathogen by the World Health Organization (WHO). Notably, A. baumannii poses a significant challenge in healthcare settings, being a leading cause of healthcare-associated infections (HAIs) responsible for diverse human illnesses, including pneumonia and septicemia. Phage therapy has reemerged as a promising avenue in addressing infections caused by multi-drug resistant A. baumannii, particularly those posing therapeutic challenges. This study aims to isolate and characterize phages active against CRAB strains isolated from HAIs in Dakar, Senegal. Methods: A lytic Acinetobacter phage vAbaIN10 was isolated from hospital wastewater in Dakar, Senegal. Various experiments, such as host-range, EOP (efficiency of plating), thermal and pH stabilities, lysis kinetics, one step growth assay and genomic analysis, were performed. Results: Phage vAbaIN10 is a member of the Caudoviricetes class and Friunavirus genus and has a 40.279 pb genome size. Phage vAbaIN10 is stable over a wide pH range (3 to 9) and at extreme temperatures (from 65?C to 70?C). The lytic activity of the phage was evaluated at various multiplicities of infection (MOI): MOI 1, 10-1 and 10-3. All MOIs considerably reduced the growth of the hosts bacteria. The one-step growth curve showed that vAbaIN10 exhibited a latent period of 25 min and has a burst size of approximately 1.2 104 phages/infected bacterial cell. No tRNA, tmRNAs, CRISPRs, virulence factors, antibiotic resistance genes were found in the genome. Conclusion: Biological and genomic characteristics of vAbaIN10 are meeting the requirements for its potential use in phage therapy. Thus, it should be further investigated.