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 hospitalacquired infections (HAIs).The hypervirulent K.pneumoniae (hvKp) 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) or hypermucoviscous (hmvKp) 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. The remaining 57 isolates (67.9%) were string negative and reported as cKp. Higher resistance rates associated with ESβL, AmpC and carbapenemase production were observed in cKp compared to hmvKp particularly those of hospital origin with a significant statistical difference (p<0.05). RmpA and iutA genes were strongly associated with hmvKp than cKp. The prevalence of blaKPC-2 gene was significantly higher in cKp (33.3%) than hmvKp (7.7%). 80.8% of the isolated hmvKp isolates proved to be hvKp (positive for both rmpA and iutA genes).Conclusions: HmvKp strains are isolated from patients with increasing frequency and constitute a significant proportion of clinical K. pneumoniae isolates. The emergence of blaKPC-producing hvKp strains in the hospital settings confirms the importance of epidemiologic surveillance and clinical awareness of this pathogen.

Occurrence and Molecular Study of Hypermucoviscous/Hypervirulence Trait in Gut Commensal K. pneumoniae from Healthy Subjects

“…It is noteworthy that the sensitivity, specificity, and accuracy of string test for identifying hvKp, compared to PCR data of encoding genes, have been assessed in various previous studies. Elbrolosy (2021) study revealed that the sensitivity, specificity, and accuracy of string test are 95.2%, 79.3%, and 86%, respectively, with a positive predictive value of 76.9% and a negative predictive value of 95.8% [ 49 ]. In addition, Russo and Gulick (2019) demonstrated string test results to identify hvKp with a specificity of 89%, a sensitivity of 91%, and an accuracy of 90% [ 27 ].…”

Distribution of rmp A gene and biofilm formation among hypervirulent klebsiella pneumoniae isolates from Ain Shams University Hospitals

“…This result in concordance with Russo et al [29] who reported results near to ours as they stated that string test had 91% sensitivity, 89% specificity. But Elbrolosy et al and Tan et al [19,33] reported higher results regarding sensitivity 95.2%, 90.5% and lower regarding specificity 79.3%, 63.9% correspondingly.…”

“…In comparison to Seifi et al [18] who found that most of K. pneumoniae were isolated from urine samples. Another study that performed in Egypt by Elbrolosy et al [19] who reported the highest rate of K. pneumoniae was isolated from blood samples followed by respiratory secretions.…”

“…Also, Guo et al and Lin et al [30,31] stated that rmpA gene was detected in 85.7%, 80.7% of strains of hvKp respectively. In an Egyptian study by Elbrolosy A et al [19] reported that the prevalence of associated rmpA gene was strongly associated with hmvKp (80.8%) than cKp strains (4.2%).…”