A phylogenetic tree of hemolysin proteins. Hemolysin proteins were obtained from GenBank and aligned. The phylogenetic tree was inferred with FastTree 2, with 1000 bootstrap replicates. Numbers at nodes indicate bootstrap support values. Numbers next to isolates are Genbank accession numbers. The diagram indicates that the hemolysin gene in A. baumannii has not been acquired by horizontal gene transfer, but rather it appears to be ancestral the Acinetobacter species.