Research Article
Characterization of Hypervirulent Klebsiella pneumoniae
(Hv-Kp): Correlation of Virulence with
Antimicrobial Susceptibility
V. Vandhana , K. Vishwas Saralaya , Sevitha Bhat , Shalini Shenoy Mulki ,
and Archana. K. Bhat
Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Mangalore 575001, Manipal,
Karnataka, India
Correspondence should be addressed to Sevitha Bhat; sevitha.bhat@manipal.edu
Received 7 December 2021; Revised 23 June 2022; Accepted 20 July 2022; Published 18 August 2022
Academic Editor: Faham Khamesipour
Copyright © 2022 V. Vandhana et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Introduction. Hypervirulent K. pneumoniae (Hv-Kp) is an emerging variant of classical K. pneumoniae (C-Kp) that exhibits hyper-
mucoviscocity and possesses multiple siderophores as virulence factors and is known to cause serious debilitating infections in im-
munocompetent individuals. Aim and objective. e aim of this study is to identify C-Kp and Hv-Kp strains and detect their virulence
factors and antimicrobial susceptibility patterns. Materials and Methods. A total of 129 K. pneumoniae isolates from different clinical
samples were used for the identification and differentiation of classical K. pneumoniae (C-Kp) and hypervirulent K. pneumoniae (Hv-
Kp) to correlate their virulence with antimicrobial susceptibility patterns and identify their risk factors. Hypermucoviscosity was
determined by a string test (>5 mm of string length). e aerobactin gene was detected by PCR. Results and Conclusion. In total, 13.9%
(18/129) were Hv-Kp and 86.1% (111/129) were C-Kp. Only 50% (9/18) of the Hv-Kp isolates were hypermucoviscous. C-Kp was
significantly more resistant to antimicrobials than Hv-Kp. Among C-Kp, 75.7% were ESBL producers and 76.6% were multidrug
resistant while in Hv-Kp, 44.44% were both ESBL producers and multidrug-resistant which is statistically significant (P < 0.01). Diabetes
was a common risk factor for C-Kp infections whereas, respiratory disorders like COPD and prolonged ICU stay were the risk factors for
Hv-Kp infections. e mortality rate among patients with Hv-Kp infections (87.5%) was significantly high when compared to that of
C-Kp infections (35.7%) (P < 0.001). A majority of hypermucoviscous K. pneumoniae isolates were multidrug resistant (65.2%).
Although the prevalence of Hv-Kp infections was low, a high percentage of them were multidrug resistant with a significantly high
mortality rate. Hence, it is important to efficiently identify Hv-Kp strains from clinical samples and determine their antimicrobial
susceptibility patterns, so as to provide immediate and effective treatment and to prevent possible outbreaks.
1. Introduction
Klebsiella pneumoniae is an opportunistic, Gram-negative en-
teric bacillus, largely known for causing community acquired
and health care associated infections. e two main pathotypes
in circulation are the classical K. pneumoniae (C-Kp) and hy-
pervirulent K. pneumoniae (Hv-Kp) [1].
C-Kp is one among the most prevalent pathogens essentially
causing health care associated infections in patients with un-
derlying comorbid conditions, existing barrier breakdown like
wound surgeries and in immunocompromised individuals [2].
e ability of this pathotype to acquire multiple elements that
confer multidrug resistance including extended spectrum of
beta-lactamases (ESBLs) and carbapenemases makes them
notorious [2, 3].
Hv-Kp is an emerging variant of C-Kp that exhibits
hypermucoviscocity and possesses multiple siderophores
as virulence factors and is known to cause serious de-
bilitating infections in immunocompetent individuals
[4, 5]. e pathotype has the potential to metastasize
from the site of infection to eye, lung, and central ner-
vous system (CNS). e infections associated with hvKp
include bacteremia, pneumonia, and soft tissue infec-
tions [6].
Hindawi
International Journal of Microbiology
Volume 2022, Article ID 4532707, 7 pages
https://doi.org/10.1155/2022/4532707