Whole-genome and comparative genomic analysis of Pseudomonas aeruginosa strain HZ15

【Objective】 The objective was to identify genes related to the synthesis of antibacterial substances in Pseudomonas aeruginosa strain HZ15，explore its antibacterial mechanisms，and investigate the genetic diversity and specificity of P. aeruginosa from different sources，providing theoretical basis for the practical application of strain HZ15. 【Method】 Using Nanopore third-generation sequencing technology，the whole-genome of P. aeruginosa strain HZ1，5 which was isolated from Lepidoptera larvae，was sequenced. Genome annotation was performed using various databases. Comparative genomics and pan-genomics analysis were conducted with 9 other P. aeruginosa strains from different environments（human，soil，plant and wastewater）. 【Result】 Strain HZ15 possessed a single chromosome of 6722482 bp， with an average GC content of 66.14%. A total of 6173 coding genes were annotated，the total length was 6018345 bp， with the coding region accounting for 89.53% of the entire genome. The comparative genomics analysis revealed variations in genome size and gene number among the 10 P. aeruginosa strains. Strain HZ15 contained 61 antibiotic resistance genes，8 prophages，53 horizontally transferred genes，and 225 virulence factors. Annotation using the CAZy database revealed that strain HZ15 possessed several glycoside hydrolases（GH18，GH19，GH₂3，GH73 and GH103）that might be related to its antibacterial activity. Furthermore，strain HZ15 harbored gene clusters encoding 3 types of metal chelators （Pf-5 pyoverdine，pseudopaline and pyochelin），as well as gene clusters for antibacterial active substances such as lankacidin C，hydrogen cyanide and bicyclomycin，along with its unique secondary metabolic synthesis related genes of lassopeptide. Pan-genomic analysis revealed that the 10 strains of P. aeruginosa had 10517 pan-genome genes and 5278 core genome genes. Within the pan-genome，strain HZ15 had 231 unique genes，among which，aphA_2 and bla genes related to antibiotic resistance. 【Conclusion】 Strain HZ15 likely inhibits pathogens through cell wall disruption，toxin release，and the production of antibacterial compounds. Its strong environmental adaptability suggests potential for application in biocontrol.