Bacteriological characteristics of hypervirulent Klebsiella pneumoniae rmpA gene (hvKp-rmpA)-harboring strains in the south of Iran

Background and Objectives: To provide data on the occurrence of classical K. pneumoniae (cKp) and hypervirulent Klebsiella pneumoniae (hvKp) strains harboring the gene encoding regulator of mucoid phenotype A (rmpA) and evaluated charac- teristics of virulence biomarkers, carbapenemase, extended-spectrum-β-lactamase (ESBL)-producing, and capsule serotypes among K. pneumoniae clinical isolates collected in the south of Iran. Materials and Methods: A total of 400 K. pneumoniae isolates were collected. First, the K. pneumoniae isolates were screened for rmpA gene by PCR, and then they were characterized for the presence of the virulence genes (pagO, iucA, iroB, luxR), capsular serotype genes (K1, K2, K5, K20, K54, and K57), carbapenemase (bla , bla IMP , bla , bla KPC , bla , bla OXA-48 , and bla ) and ESBL (bla CTX-M SHV and bla TEM ) genes. For all K. pneumoniae isolates phenotypic tests include of string test and disk diffusion test were performed. Results: In total, 16 (4%) hvKp-rmpA+ and 384 (96%) cKp were observed. Of hvKp-rmpA+ strains, 16 (100%) were carried pagO, iroB, and luxR genes, and 13 (81.3%) strains harbored iucA gene. The most prevalent capsular type genes were K1 (62%) and K2 (19%) in hvKp-rmpA+ strains. The incidence of bla SHV gene in hvKp and cKp was 94% (15/16) and 87.5% (336/384), respectively. The cKp isolates carried bla NDM (30/384; 7.8%) gene. Conclusion: Our data suggest that the incidence of hvKp was low. Also, hvKp-rmpA+ strains have less antibiotic resistance than cKp isolates. Serotypes K1 and K2, and bla SHV gene were strongly associated with hvKp-rmpA+.