TY - JOUR
T1 - Virulence Characteristics of Carbapenem-Resistant Klebsiella pneumoniae Strains from Patients with Necrotizing Skin and Soft Tissue Infections
AU - Krapp, Fiorella
AU - Morris, Andrew R.
AU - Ozer, Egon A.
AU - Hauser, Alan R.
N1 - Funding Information:
The authors thank Chao Qi and the staff of the Clinical Microbiological Laboratory and Teresa Zembower and the Healthcare Epidemiology and Infection Prevention Committee of Northwestern Memorial Hospital for their technical support in performing this study. This work was supported by National Institute of Allergy and Infectious Diseases (NIAID) grants K24 AI104831, R01 AI053674, R01 AI118257, and matching funds from the Department of Medicine, Feinberg School of Medicine, Northwestern University for T32 AI095207.
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Two types of Klebsiella pneumoniae (KP) strains are currently emerging: hypervirulent (hvKP) strains and carbapenem-resistant (CR-KP) strains. To date, these two strain types rarely overlap. Recent reports, however, suggest that CR-KP strains are increasing in virulence. hvKP strains frequently present as highly invasive infections, such as necrotizing skin and soft tissue infections (NSSTI). To examine whether CR-KP strains with features of hvKP were present in our U.S. hospital, we retrospectively identified four cases of CR-KP NSSTI diagnosed between January 2012 and January 2016. Whole-genome sequencing was used to perform multilocus sequence typing, capsular typing, and identification of virulence and antimicrobial resistance genes. Additionally, the virulence of each isolate was determined in vitro and using murine pneumonia and subcutaneous infection models. We identified one CR-KP isolate that possessed features of hypervirulent KP, including a hypermucoviscous phenotype, K2 capsule, and resistance to phagocytosis. Of the four CR-KP isolates, two had no evidence of enhanced pathogenicity in either mouse model, demonstrating that low-virulence strains can cause NSSTI in immunosuppressed patients. The remaining two isolates exhibited low virulence in the pneumonia model but high virulence in the subcutaneous infection model, suggesting that the virulence attributes of these isolates are adapted to causing NSSTI.
AB - Two types of Klebsiella pneumoniae (KP) strains are currently emerging: hypervirulent (hvKP) strains and carbapenem-resistant (CR-KP) strains. To date, these two strain types rarely overlap. Recent reports, however, suggest that CR-KP strains are increasing in virulence. hvKP strains frequently present as highly invasive infections, such as necrotizing skin and soft tissue infections (NSSTI). To examine whether CR-KP strains with features of hvKP were present in our U.S. hospital, we retrospectively identified four cases of CR-KP NSSTI diagnosed between January 2012 and January 2016. Whole-genome sequencing was used to perform multilocus sequence typing, capsular typing, and identification of virulence and antimicrobial resistance genes. Additionally, the virulence of each isolate was determined in vitro and using murine pneumonia and subcutaneous infection models. We identified one CR-KP isolate that possessed features of hypervirulent KP, including a hypermucoviscous phenotype, K2 capsule, and resistance to phagocytosis. Of the four CR-KP isolates, two had no evidence of enhanced pathogenicity in either mouse model, demonstrating that low-virulence strains can cause NSSTI in immunosuppressed patients. The remaining two isolates exhibited low virulence in the pneumonia model but high virulence in the subcutaneous infection model, suggesting that the virulence attributes of these isolates are adapted to causing NSSTI.
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U2 - 10.1038/s41598-017-13524-8
DO - 10.1038/s41598-017-13524-8
M3 - Article
C2 - 29051525
AN - SCOPUS:85044740333
VL - 7
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
IS - 1
M1 - 13533
ER -