Molecular Typing and Virulence Analysis of Serotype K1 Klebsiella pneumoniae Strains Isolated from Liver Abscess Patients and Stool Samples from Noninfectious Subjects in Hong Kong, Singapore, and Taiwan

Siu, L. Kristopher; Fung, Chang-Phoné; Chang, Feng–Yee; Lee, Nelson; Yeh, Kuo-Ming; Koh, Tse Hsien; Ip, Margaret

doi:10.1128/jcm.00977-11

Cited by 180 publications

(157 citation statements)

References 25 publications

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“…These data build on previous observations made from a restricted number of isolates (47,56,57) by showing that the effect on virulence of acquiring iron-scavenging genes is not dependent on strain background or on specific combinations of siderophores and that the acquisition of iron-scavenging systems is central to the ability of K. pneumoniae to cause invasive disease in nonimmunocompromised patients. Importantly, this finding suggests that the acquisition of any one of the siderophore clusters increases the risk of severe infection in humans.…”

Section: Resultssupporting

confidence: 82%

Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae , an urgent threat to public health

Holt

Wertheim

Zadoks

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

963

1,110

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Klebsiella pneumoniae is now recognized as an urgent threat to human health because of the emergence of multidrug-resistant strains associated with hospital outbreaks and hypervirulent strains associated with severe community-acquired infections. K. pneumoniae is ubiquitous in the environment and can colonize and infect both plants and animals. However, little is known about the population structure of K. pneumoniae, so it is difficult to recognize or understand the emergence of clinically important clones within this highly genetically diverse species. Here we present a detailed genomic framework for K. pneumoniae based on whole-genome sequencing of more than 300 human and animal isolates spanning four continents. Our data provide genome-wide support for the splitting of K. pneumoniae into three distinct species, KpI (K. pneumoniae), KpII (K. quasipneumoniae), and KpIII (K. variicola). Further, for K. pneumoniae (KpI), the entity most frequently associated with human infection, we show the existence of >150 deeply branching lineages including numerous multidrug-resistant or hypervirulent clones. We show K. pneumoniae has a large accessory genome approaching 30,000 protein-coding genes, including a number of virulence functions that are significantly associated with invasive community-acquired disease in humans. In our dataset, antimicrobial resistance genes were common among human carriage isolates and hospital-acquired infections, which generally lacked the genes associated with invasive disease. The convergence of virulence and resistance genes potentially could lead to the emergence of untreatable invasive K. pneumoniae infections; our data provide the whole-genome framework against which to track the emergence of such threats.

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Section: Resultssupporting

confidence: 82%

Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae , an urgent threat to public health

Holt

Wertheim

Zadoks

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

963

1,110

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“…One study characterizing HV K. pneumoniae strains isolated from 4 different continents found that these strains were almost exclusively K1 strains (93%), while the remaining minority were K2 strains (235), a finding consistent with results of previous studies (18,(236)(237)(238)(239)(240)(241). Interestingly, in one study, 27/28 of the K1 HV K. pneumoniae isolates belonged to the same clonal complex (CC23), while the two K2 HV strains examined were genetically unrelated and arose from two distinct clonal lineages (ST25 and ST86) (235).…”

Section: Capsulesupporting

confidence: 85%

Klebsiella pneumoniae: Going on the Offense with a Strong Defense

Paczosa

Mecsas

2016

Microbiol Mol Biol Rev

1,212

1,282

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SUMMARYKlebsiella pneumoniaecauses a wide range of infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Historically,K. pneumoniaehas caused serious infection primarily in immunocompromised individuals, but the recent emergence and spread of hypervirulent strains have broadened the number of people susceptible to infections to include those who are healthy and immunosufficient. Furthermore,K. pneumoniaestrains have become increasingly resistant to antibiotics, rendering infection by these strains very challenging to treat. The emergence of hypervirulent and antibiotic-resistant strains has driven a number of recent studies. Work has described the worldwide spread of one drug-resistant strain and a host defense axis, interleukin-17 (IL-17), that is important for controlling infection. Four factors, capsule, lipopolysaccharide, fimbriae, and siderophores, have been well studied and are important for virulence in at least one infection model. Several other factors have been less well characterized but are also important in at least one infection model. However, there is a significant amount of heterogeneity inK. pneumoniaestrains, and not every factor plays the same critical role in all virulentKlebsiellastrains. Recent studies have identified additionalK. pneumoniaevirulence factors and led to more insights about factors important for the growth of this pathogen at a variety of tissue sites. Many of these genes encode proteins that function in metabolism and the regulation of transcription. However, much work is left to be done in characterizing these newly discovered factors, understanding how infections differ between healthy and immunocompromised patients, and identifying attractive bacterial or host targets for treating these infections.

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“…5 The emerging serotype K1 K. pneumoniae with multilocus sequence type 23 has been strongly associated with the virulence of liver abscess and invasive syndrome. 6,7 ALA has not been a topic of focus, but it is a potentially life-threatening complication by infection with the protozoan parasite Entamoeba histolytica. 8 ALA is widely distributed throughout the tropics and subtropics, causing up to 40 million infections annually.…”

Section: Introductionmentioning

confidence: 99%

Burden of Liver Abscess and Survival Risk Score in Thailand: A Population-Based Study

Poovorawan¹,

Pan-ngum²,

Soonthornworasiri³

et al. 2016

The American Journal of Tropical Medicine and Hygiene

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Abstract. In Thailand, the burden of liver abscess, a life-threatening infectious disease, has not been thoroughly evaluated. We developed a predictive scoring system to estimate survival of patients with liver abscess using information from the 2008-2013 Nationwide Hospital Admission Data to evaluate the burden of liver abscess in Thailand. All patients with primary diagnosis of pyogenic liver abscess (PLA) and amoebic liver abscess (ALA) were included. Epidemiological data, baseline characteristics, hospital course, and survival were analyzed. Overall, 11,296 admissions comprising 8,423 patients from 844 hospitals across Thailand were eligible for analysis. The mean age was 52 ± 17 years and 66.1% of patients were male. ALA was significantly prevalent in southern and western border regions of Thailand, and PLA occurred nationwide. The highest incidence of liver abscess occurred in the rainy season (June-November, P < 0.01). The median length of hospital stay was 8 days (interquartile range = 4-13 days), and mean direct cost of hospitalization was 846 ± 1,574 USD. The overall inhospital mortality rate was 2.8%. Incidence of ALA decreased over the 5-year study period, whereas PLA incidence increased (P < 0.01). Using multivariable Cox regression methods with stepwise variable selection, we developed a final model with five highly significant baseline parameters associated with increased 60-day mortality: older age, PLA, underlying chronic kidney disease, cirrhosis, and human immunodeficiency virus infection. Range of estimated probability of 60-day survival was 95-16% at cumulative risk score 0-13. This simplified score is practical, and may help clinicians prioritize patients requiring more intensive care.

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Molecular Typing and Virulence Analysis of Serotype K1 Klebsiella pneumoniae Strains Isolated from Liver Abscess Patients and Stool Samples from Noninfectious Subjects in Hong Kong, Singapore, and Taiwan

Cited by 180 publications

References 25 publications

Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae , an urgent threat to public health

Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae , an urgent threat to public health

Klebsiella pneumoniae: Going on the Offense with a Strong Defense

Burden of Liver Abscess and Survival Risk Score in Thailand: A Population-Based Study

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