Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jun 15;11(3):e0035923.
doi: 10.1128/spectrum.00359-23. Epub 2023 May 16.

A 20-Year Study of Capsular Polysaccharide Seroepidemiology, Susceptibility Profiles, and Virulence Determinants of Klebsiella pneumoniae from Bacteremia Patients in Taiwan

Affiliations

A 20-Year Study of Capsular Polysaccharide Seroepidemiology, Susceptibility Profiles, and Virulence Determinants of Klebsiella pneumoniae from Bacteremia Patients in Taiwan

Chun-Chou Tsai et al. Microbiol Spectr. .

Abstract

In this study, we selected bacteremic Klebsiella pneumoniae isolates from the Taiwan Surveillance of Antimicrobial Resistance program. A total of 521 isolates were collected over a period of 2 decades, including 121 from 1998, 197 from 2008, and 203 from 2018. Seroepidemiology showed that the top five capsular polysaccharide types were serotypes K1, K2, K20, K54, and K62, constituting 48.5% of the total isolates, and the respective ratios at each time point have remained similar over the past 2 decades. The antibacterial susceptibility tests showed that K1, K2, K20, and K54 were susceptible to most antibiotics, while K62 was relatively resistant compared to other typeable and nontypeable strains. In addition, six virulence-associated genes, clbA, entB, iroN, rmpA, iutA, and iucA, were predominant in K1 and K2 isolates of K. pneumoniae. In conclusion, serotypes K1, K2, K20, K54, and K62 of K. pneumoniae are the most prevalent serotypes and carry more virulence determinants in bacteremia patients, which may indicate their invasiveness. If further serotype-specific vaccine development is performed, these five serotypes should be included. Since the antibiotic susceptibility profiles were stable over a long duration, empirical treatment may be predicted according to serotype if rapid diagnosis from direct clinical specimens is available, such as PCR or antigen serotyping for serotype K1 and K2. IMPORTANCE This is the first nationwide study to examine the seroepidemiology of Klebsiella pneumoniae using blood culture isolates collected over a period of 20 years. The study found that the prevalence of serotypes remained consistent over the 20-year period, with high-prevalence serotypes associated with invasive types. Nontypeable isolates had fewer virulence determinants than other serotypes. With the exception of serotype K62, the other high-prevalence serotypes were highly susceptible to antibiotics. If rapid diagnosis using direct clinical specimens, such as PCR or antigen serotyping, is available, empirical treatment can be predicted based on serotype, particularly for K1 and K2. The results of this seroepidemiology study could also help the development of future capsule polysaccharide vaccines.

Keywords: Klebsiella pneumoniae; resistance; serotyping; virulence.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

FIG 1
FIG 1
Hospital distribution of blood culture isolates of K. pneumoniae collected from 1998 to 2018 for this study.

References

    1. Fung CP, Chang FY, Lee SC, Hu BS, Kuo BI, Liu CY, Ho M, Siu LK. 2002. A global emerging disease of Klebsiella pneumoniae liver abscess: is serotype K1 an important factor for complicated endophthalmitis? Gut 50:420–424. doi:10.1136/gut.50.3.420. - DOI - PMC - PubMed
    1. Kang CI, Kim SH, Bang JW, Kim HB, Kim NJ, Kim EC, Oh MD, Choe KW. 2006. Community-acquired versus nosocomial Klebsiella pneumoniae bacteremia: clinical features, treatment outcomes, and clinical implication of antimicrobial resistance. J Korean Med Sci 21:816–822. doi:10.3346/jkms.2006.21.5.816. - DOI - PMC - PubMed
    1. Tsay RW, Siu LK, Fung CP, Chang FY. 2002. Characteristics of bacteremia between community-acquired and nosocomial Klebsiella pneumoniae infection: risk factor for mortality and the impact of capsular serotypes as a herald for community-acquired infection. Arch Intern Med 162:1021–1027. doi:10.1001/archinte.162.9.1021. - DOI - PubMed
    1. Opoku-Temeng C, Kobayashi SD, DeLeo FR. 2019. Klebsiella pneumoniae capsule polysaccharide as a target for therapeutics and vaccines. Comput Struct Biotechnol J 17:1360–1366. doi:10.1016/j.csbj.2019.09.011. - DOI - PMC - PubMed
    1. Pan YJ, Lin TL, Chen CT, Chen YY, Hsieh PF, Hsu CR, Wu MC, Wang JT. 2015. Genetic analysis of capsular polysaccharide synthesis gene clusters in 79 capsular types of Klebsiella spp. Sci Rep 5:15573. doi:10.1038/srep15573. - DOI - PMC - PubMed

Publication types

LinkOut - more resources