Molecular and Clinical Characterization of Multidrug-Resistant and Hypervirulent Klebsiella pneumoniae Strains from Liver Abscess in Taiwan

Abstract

Hypervirulent Klebsiella pneumoniae strains are the major cause of liver abscesses throughout East Asia, and these strains are usually antibiotic susceptible. Recently, multidrug-resistant and hypervirulent (MDR-HV) K. pneumoniae strains have emerged due to hypervirulent strains acquiring antimicrobial resistance determinants or the transfer of a virulence plasmid into a classic MDR strain. In this study, we characterized the clinical and microbiological properties of K. pneumoniae liver abscess (KPLA) caused by MDR-HV strains in Taiwan. Patients with community onset KPLA were retrospectively identified at Taipei Veterans General Hospital during January 2013 to May 2018. Antimicrobial resistance mechanisms, capsular types, and sequence types were determined. MDR-HV strains and their parental antimicrobial-susceptible strains further underwent whole-genome sequencing (WGS) and in vivo mice lethality tests. Thirteen MDR-HV strains were identified from a total of 218 KPLA episodes. MDR-HV strains resulted in similar outcomes to antimicrobial-susceptible strains. All MDR-HV strains were traditional hypervirulent clones carrying virulence capsular types. The major resistance mechanisms were the overexpression of efflux pumps and/or the acquisition of ESBL or AmpC β-lactamase genes. WGS revealed that two hypervirulent strains had evolved to an MDR phenotype due to mutation in the ramR gene and the acquisition of an SHV-12-bearing plasmid, respectively. Both these MDR-HV strains retained high virulence compared to their parental strains. The spread of MDR-HV K. pneumoniae strains in the community raises significant public concerns, and measures should be taken to prevent the further acquisition of carbapenemase and other resistance genes among these strains in order to avoid the occurrence of untreatable KPLA.

Klebsiella pneumoniae-related invasive liver abscess syndrome complicated by purulent meningitis: a review of the literature and description of three cases

“…Besides the 100% mortality, all of the three patients had comatose mental status, septic shock, and live abscesses, the characters tallied with the reported study and may due to the high virulence of K. pneumoniae. What’s worse, multidrug-resistant and hypervirulent (MDR-HV) K. pneumoniae strains had spread in the community, 13 MDR-HV strains were identified from a total of 218 K. pneumoniae liver abscess episodes in a Taiwan Hospital [ 34 ]. Given the three cases in our study all occurred in one city in Hebei province, a future study might examine the particular virulence factors of this strain of K. pneumoniae .…”

Change of Hypermucoviscosity in the Development of Tigecycline Resistance in Hypervirulent Klebsiella pneumoniae Sequence Type 23 Strains

“…Serotype K1 is the most common among the hypermucoviscous K. pneumoniae [ 1 ], and the close association with the serotype and genotype ST23 is well-known [ 7 , 27 ]. Thus, the emergence of antimicrobial resistance in this pathogenic clone should be a concern [ 28 ].…”

Surgery combined with antibiotics for the treatment of endogenous endophthalmitis caused by liver abscess

“…The ideal condition for performing a bacterial culture is during the absence of antibiotic treatment following disease onset. However, due to the rapid progression of the disease, and the lack of a standardized antibiotic treatment strategy for endogenous endophthalmitis, it is difficult to control this condition, and the results of the culture may be unreliable [ 17 ]. Therefore, for effective management of endogenous endophthalmitis, blood samples should be collected before starting antibiotic treatment [ 18 ].…”