Comparative Studies on Clinical Isolates of Hypervirulent and Classical Klebsiella pneumoniae

Abstract

Hypervirulent Klebsiella pneumonia (hvKP), typically linked with the hypermucoviscous phenotype, has evolved as a clinically significant pathogen responsible for catastrophic disseminated infections including osteomyelitis, pyogenic liver abscesses (PLA), and endophthalmitis in an otherwise younger and healthier population. Methods: Mansoura University Hospitals, Egypt have utilised VITEK® 2 to identify clinical K. pneumoniae isolates. The Kirby Bauer's disc diffusion method was employed to asses sensitivity to antimicrobial. String test for detecting microvasculitis, Serotyping, and Bio-typing are among the phenotypic methods employed. Polymerase chain reaction (PCR) was performed to amplify capsular serotype-specific genes (K1 and K2) as well as virulence-associated genes (rmpA and magA). Results: Over two-years, 100 hypermucoviscous phenotype K. pneumoniae and 100 classical K. pneumoniae strains were isolated and screened by string test. Hypermucoviscosity Serotyping revealed that 76 isolates had K1-type capsules, 19 had K2-type capsules, and 5 were non-K1/K2 isolates. Among the positive hypermucoviscusisolates, the prevalence of rmpA gene was 79 %, and magA gene was 40 %. Although, the prevalence of these two genes in classical Klebsiella pneumoniae (cKP) isolates was very low 11% and 7%, respectively. Aside from that, the occurrence of K capsular genes in hvKP isolates were; K1 gene 66% and K2 gene 63%.However, the occurrence of these genes in cKP isolates were limited. Conclusion: In our geographical area, hypervirulent Klebsiella pneumoniae hvKP isolates were infrequent among K. pneumoniae isolates (El-Mansoura, Egypt). This study summarized and concentrated on the epidemiology, hypervirulence-associated variables, and antibiotic resistance mechanisms of hvKP strains. This was done to let the microbiologist or clinician know that the infecting strain could be hvKP, which is more dangerous than cKP. As a result, detecting these hypervirulent strains, which harbor resistance variants, should be a top goal priority.