Genomic analysis of multidrug-resistant CTX-M-15-positive Klebsiella pneumoniae belonging to the highly successful ST15 clone isolated from a dog with chronic otitis

Abstract

Background: Extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae have been increasingly reported worldwide as a frequent cause of human and animal infections. K. pneumoniae belonging to the K24 capsular serotype and sequence type (ST) ST15 has been considered a global successful clone responsible for the spread of the blaCTX-M-15 gene. Objective: To report the draft genome sequence of a multidrug-resistant CTX-M-15-positive K. pneumoniae K24-ST15 strain (L3KP1), which was isolated from a dog with chronic otitis. Methods: Genomic DNA was extracted and sequenced using Illumina NextSeq platform. De novo assembly was performed by SPAdes and in silico prediction accomplished by curated bioinformatics tools. Results: The genome size was calculated at 5 642 348 bp, with a GC content of 57.11%, and comprising 5601 total genes, 52 tRNAs, 8 rRNAs, 9 ncRNAs and 105 pseudogenes. The K. pneumoniae L3KP1 strain belonged to ST15 and carried the yersiniabactin biosynthetic gene cluster [ybt 10 (YbST28) in the integrative conjugative element ICEKp4], and the KL24 locus encoding capsular serotype K24. Besides the blaCTX-M-15 ESBL gene, other clinically important resistance genes to β-lactams, aminoglycosides, fosfomycin, macrolides, phenicol, quinolones, sulfonamides, tetracyclines and trimethoprim were detected. Additionally, heavy metals and disinfectant resistance genes were also identified. Conclusion: This draft genome might be useful for comparative genomic analyses of the international clone of K. pneumoniae K24-ST15-CTX-M-15. In addition, information presented in this study also shed light on the urgent need to monitor ESBL-producing K. pneumoniae in veterinary hospitals.