Characterization and genome sequencing of SH-Ab 15599, a novel bacteriophage targeting carbapenem-resistant Acinetobacter baumannii / 上海交通大学学报（医学版）

ABSTRACT

Objective • To find lytic bacteriophages which have potential to combat carbapenem-resistant Acinetobacter baumannii (CRAB) infections and analyze the biological characterizations and genomic sequences of the phages. Methods • The phages were isolated from sewage followed by amplification and purification. They were characterized by the transmission electron microscopy, the host specificity, the biological characterizations, the lysis assay in vitro and the genome sequence analysis. Results • A novel bacteriophage, SH-Ab 15599, was isolated from sewage. The electron microscope revealed SH-Ab 15599 belongs to Myoviridae. Among the 51 clinical CRAB isolates tested, 15 (29.4%) were lysed by the phage. SH-Ab 15599 was relatively stable at temperature range from 4℃ to 50℃ or between pH 6 and 9. About 90% of the phage was approximately adsorbed to the host CRAB isolate in 5 min. The one-step growth curve showed that the latent period was about 10 min and the growth period was about 20 min. The burst size was estimated at 43 pfu per infected cell. The growth of the host CRAB isolate was inhibited by the phage in vitro. The genome of SH-Ab 15599 was a linear, 143 204 bp double-stranded DNA with GC content of 38.45%. Conclusion • SH-Ab 15599 is a novel phage targeting CRAB and has potential as an alternative against CRAB infections in the future.