Characterization of virulence genetic profile and resistance patterns of clinical Klebsiella pneumoniae isolates: Classic versus hypermucoviscous phenotypes

Abstract

Background: Klebsiella pneumoniae (K. pneumoniae) is one of the most clinically important opportunistic pathogens involved in both community-(CAIs) and hospital-acquired infections (HAIs).The hypervirulent K.pneumoniae (hvKp < /em>) responsible for disseminated infections in healthy and immunosuppressed individuals has emerged with considerable ability to get antibiotic resistance as well. We aimed to characterize the virulence genetic profile and resistance phenotypes of the clinical K.pneumoniae isolates at Menoufia University Hospitals (MUHs) by phenotypic and molecular methods. Methods: 84 K.pneumoniae isolates were collected and classified as classic (cKp < /em>) or hypermucoviscous (hmvKp < /em>) phenotypes by string test. Antimicrobial resistance patterns were determined phenotypically and multiplex PCR verified the existence of some of the suspected virulence genes. Results: Out of 84 K.pneumoniae isolates, 27 (32.1%) had a positive string test and identified as hmvKp < /em>. The remaining 57 isolates (67.9%) were string negative and reported as cKp < /em>. Higher resistance rates associated with ESβL, AmpC and carbapenemase production were observed in cKp < /em> compared to hmvKp < /em> particularly those of hospital origin with a significant statistical difference (p < 0.05). RmpA and iutA genes were strongly associated with hmvKp < /em> than cKp < /em>. The prevalence of blaKPC-2 gene was significantly higher in cKp < /em> (33.3%) than hmvKp < /em> (7.7%). 80.8% of the isolated hmvKp < /em> isolates proved to be hvKp < /em> (positive for both rmpA and iutA genes). Conclusions: HmvKp < /em> strains are isolated from patients with increasing frequency and constitute a significant proportion of clinical K. pneumoniae isolates. The emergence of blaKPC-producing hvKp < /em> strains in the hospital settings confirms the importance of epidemiologic surveillance and clinical awareness of this pathogen.