Antibacterial properties of Acinetobacter baumanniiphage Abp1 endolysin (PlyAB1)

BACKGROUND: Acinetobacter baumannii has emerged as one of the most important hospital-acquired pathogens in the world, because of its resistance to almost all available antibiotic drugs. Endolysins from phages are attracting increasing interest as potential antimicrobial agents, especially for drug-resistant bacteria. We previously isolated and characterized Abp1, a virulent phage targeting the multidrug-resistant A. baumannii strain, AB1. METHODS: To evaluate the antimicrobial potential of endolysin from the Abp1 phage, the endolysin gene plyAB1 was cloned and over-expressed in Escherichia coli, and the lytic activity of the recombinant protein (PlyAB1) was tested by turbidity assessment and bacteria counting assays. RESULTS: PlyAB1 exhibits a marked lytic activity against A. baumannii AB1, as shown by a decrease in the number of live bacteria following treatment with the enzyme. Moreover, PlyAB1 displayed a highly specific lytic effect against all of the 48 hospital-derived pandrug-resistant A. baumannii isolates that were tested. These isolates were shown to belong to different ST clones by multilocus sequence typing. CONCLUSIONS: The results presented here show that PlyAB1 has potential as an antibiotic against drug-resistant A. baumannii. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-014-0681-2) contains supplementary material, which is available to authorized users.