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

Saeed Shoja; Maryam Ansari; Saman Bengar; Azam Rafiei; Jebreil Shamseddin; Hesam Alizade

doi:10.18502/ijm.v14i4.10233

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

Iran J Microbiol. 2022 Aug;14(4):475-483. doi: 10.18502/ijm.v14i4.10233.

Authors

Saeed Shoja¹, Maryam Ansari¹, Saman Bengar², Azam Rafiei¹, Jebreil Shamseddin¹, Hesam Alizade¹

Affiliations

¹ Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
² Student Research Committee, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.

Abstract

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 characteristics 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 _NDM, bla _IMP, bla _VIM, bla _KPC, bla _SPM, bla _OXA-48, and bla _OXA-181) and ESBL (bla _CTX-M, bla _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+.

Keywords: Beta-lactamases; Carbapenem-resistant Enterobacteriaceae; Klebsiella pneumonia.