Disguised as Ovarian Tumor: A Rare Case of Uterine Abscess Due to Hypervirulent Klebsiella pneumoniae Infection.
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ABSTRACT:
SUBMITTER: Kamau E
PROVIDER: S-EPMC9310266 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Hypervirulent K. pneumoniae (hvKp) is an evolving pathotype that is more virulent than classical K. pneumoniae (cKp). hvKp usually infects individuals from the community, who are often healthy. Infections are more common in the Asian Pacific Rim but are occurring globally. hvKp infection frequently presents at multiple sites or subsequently metastatically spreads, often requiring source control. hvKp has an increased ability to cause central nervous system infection and endophthalmitis, which require rapid recognition and site-specific treatment. The genetic factors that confer hvKp's hypervirulent phenotype are present on a large virulence plasmid and perhaps integrative conjugal elements. Increased capsule production and aerobactin production are established hvKp-specific virulence factors. Similar to cKp, hvKp strains are becoming increasingly resistant to antimicrobials via acquisition of mobile elements carrying resistance determinants, and new hvKp strains emerge when extensively drug-resistant cKp strains acquire hvKp-specific virulence determinants, resulting in nosocomial infection. Presently, clinical laboratories are unable to differentiate cKp from hvKp, but recently, several biomarkers and quantitative siderophore production have been shown to accurately predict hvKp strains, which could lead to the development of a diagnostic test for use by clinical laboratories for optimal patient care and for use in epidemiologic surveillance and research studies.
| S-EPMC6589860 | biostudies-literature
Project description:To map the Hfq-mediated RNA regulatory network in HvKP, we harnessed the LiRIP-seq approach recently established in our lab, which enabled global profiling of RNA-RNA interactomes in live bacteria. Transformation of the pBAD-t4rnl1 plasmid into Klebsiella allowed us to express T4 RNA ligase 1 for proximity-ligation of RNAs in vivo, followed by co-immunoprecipitation (coIP) to enrich the Hfq-bound RNA transcripts (singleton reads) and ligated RNA fragments (chimeras: sRNA-mRNA, sRNA-sRNA, etc).
2024-07-17 | GSE243246 | GEO
Project description:ImportanceHypervirulent variants of Klebsiella pneumoniae (hvKp) are capable of causing life-threatening pyogenic liver abscesses (PLAs), but hvKp caused PLAs was seldom reported in pediatric populations. Hence, there is an urgent need to raise our awareness of this phenomenon in pediatric populations.ObjectiveThis study aimed to report the clinical characteristics of hvKp that caused fatal PLA complicated by bacteremia in an adolescent and further identify the microbiological and genomic features of the causative strain.MethodsA 14-year-old boy with diabetes mellitus was admitted to our hospital with a diagnosis of PLA complicated by bacteremia. A hypermucoviscous hvKp strain, KPN_19-106, was isolated from the drainage fluid present within the liver abscess cavity and blood. The hypermucoviscosity phenotype of the causative strain was determined by string test. Its virulence was measured using serum resistance assay and Galleria mellonella larvae-killing assay. Antimicrobial susceptibility was determined by broth microdilution method. Genetic information was obtained by whole-genome sequencing and bioinformatics analysis.ResultsKPN_19-106 belonged to sequence type 380 and serotype K2 and exhibited stronger serum resistance and higher in vivo lethality than the well-characterized hvKp NTUH-K2044 strain. Although KPN_19-106 is susceptible to most antibiotics, no sign of improvement was observed during treatment with such drugs. Whole-genome sequencing revealed that the isolate had integrated multiple mobile genetic elements related to virulence.InterpretationAntibiotic-susceptible hvKp can cause fatal PLA complicated by bacteremia in adolescents, with no improvement during antimicrobial therapy. The causative strain in this case had integrated multiple virulence genes and thus exhibited higher virulence both in vitro and in vivo when compared with NTUH-K2044.
| S-EPMC8212719 | biostudies-literature
Project description: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 ?-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.
| S-EPMC7179640 | biostudies-literature
Project description:Ventilator-associated pneumonia (VAP) and pyogenic liver abscess (PLA) due to Klebsiella pneumoniae infection can trigger life-threatening malignant consequences, however, there are few studies on the strain-associated clinical pathogenic mechanisms between VAP and PLA. A total of 266 patients consist of 129 VAP and 137 PLA were included for analysis in this study. We conducted a comprehensive survey for the two groups of K. pneumoniae isolates, including phenotypic experiments, clinical epidemiology, genomic analysis, and instrumental analysis, i.e., to obtain the genomic differential profile of K. pneumoniae strains responsible for two distinct infection outcomes. We found that PLA group had a propensity for specific underlying diseases, especially diabetes and cholelithiasis. The resistance level of VAP was significantly higher than that of PLA (78.57% vs. 36%, P < 0.001), while the virulence results were opposite. There were also some differences in key signaling pathways of biochemical processes between the two groups. The combination of iucA, rmpA, hypermucoviscous phenotype, and ST23 presented in K. pneumoniae infection is more important and highly prudent for timely treatment. The present study may contribute a benchmark for the K. pneumoniae clinical screening, epidemiological surveillance, and effective therapeutic strategies.
| S-EPMC10644596 | biostudies-literature
Project description:Hypervirulent Klebsiella pneumoniae (hvKP) has raised grave concerns in recent years and can cause severe infections with diverse anatomic locations including liver abscess, meningitis, and endophthalmitis. However, there is limited data about neck abscess caused by hvKP. A K. pneumoniae strain Kp_whw was isolated from neck abscess. We characterized the genetic background, virulence determinates of the strain by genomic analysis and dertermined the virulence level by serum resistance assay. Kp_whw belonged to sequence type (ST) 1049 K locus (KL) 5. Kp_whw showed hypermucoviscosity phenotype and was resistant to ampicillin but susceptible to the majority of the other antimicrobial agents. A pLVPK-like virulence plasmid and a chromosomal ICEKp5-like mobile genetic element were carried by Kp_whw, resulting in the risk of dissemination of hypervirulence. The strain exhibited relative higher level of core genome allelic diversity than accessory genome profile, in comparison to hvKP of K1/K2 serotype. Kp_whw was finally demonstrated as virulent as the ST23 K1 serotype hvKP strain NTUH-K2044 in vitro. In conclusion, this work elaborates the genetic background of a clinical hvKP strain with an uncommon ST, reinforcing our understanding of virulence mechanisms of hvKP.
| S-EPMC7848818 | biostudies-literature
Project description:Emphysematous prostatic abscess (EPA) is an extremely rare but potentially fatal urinary tract infection (UTI). Here, we describe a case (a 69-year-old male with prediabetes) of ruptured EPA caused by a hypervirulent Klebsiella pneumoniae (hvKp) K1-ST23 strain, presenting as motor aphasia. Our patient presented with ruptured EPA concurrent with various severe systemic pyogenic complications (e.g., urethro-prostatic fistula, ascending UTIs, epididymal and scrotal abscesses, and liver, lung, and brain abscesses). Whole-body computed tomography (CT) and next-generation sequencing (NGS) were useful for the detection of ruptured EPA and its systemic complications, and for identification of K1-ST23 hvKp strains, respectively. Subsequently, the infections were successfully treated with aggressive antimicrobial therapy and multiple surgical procedures. This case highlights the significance of awareness of this rare entity, the clinical importance of CT for the early diagnosis of EPA and the detection of its systemic complications in view of hvKp being an important causative organism of severe community-acquired UTI, and the usefulness of NGS to identify hvKp strains.
| S-EPMC8761798 | biostudies-literature
Project description:UnlabelledHighly invasive, community-acquired Klebsiella pneumoniae infections have recently emerged, resulting in pyogenic liver abscesses. These infections are caused by hypervirulent K. pneumoniae (hvKP) isolates primarily of capsule serotype K1 or K2. Hypervirulent K1 isolates belong to clonal complex 23 (CC23), indicating that this clonal lineage has a specific genetic background conferring hypervirulence. Here, we apply whole-genome sequencing to a collection of K. pneumoniae isolates to characterize the phylogenetic background of hvKP isolates with an emphasis on CC23. Most of the hvKP isolates belonged to CC23 and grouped into a distinct monophyletic clade, revealing that CC23 is a unique clonal lineage, clearly distinct from nonhypervirulent strains. Separate phylogenetic analyses of the CC23 isolates indicated that the CC23 lineage evolved recently by clonal expansion from a single common ancestor. Limited grouping according to geographical origin was observed, suggesting that CC23 has spread globally through multiple international transmissions. Conversely, hypervirulent K2 strains clustered in genetically unrelated groups. Strikingly, homologues of a large virulence plasmid were detected in all hvKP clonal lineages, indicating a key role in K. pneumoniae hypervirulence. The plasmid encodes two siderophores, aerobactin and salmochelin, and RmpA (regulator of the mucoid phenotype); all these factors were found to be restricted to hvKP isolates. Genomic comparisons revealed additional factors specifically associated with CC23. These included a distinct variant of a genomic island encoding yersiniabactin, colibactin, and microcin E492. Furthermore, additional novel genomic regions unique to CC23 were revealed which may also be involved in the increased virulence of this important clonal lineage.ImportanceDuring the last 3 decades, hypervirulent Klebsiella pneumoniae (hvKP) isolates have emerged, causing severe community-acquired infections primarily in the form of pyogenic liver abscesses. This syndrome has so far primarily been found in Southeast Asia, but increasing numbers of cases are being reported worldwide, indicating that the syndrome is turning into a globally emerging disease. We applied whole-genome sequencing to a collection of K. pneumoniae clinical isolates to reveal the phylogenetic background of hvKP and to identify genetic factors associated with the increased virulence. The hvKP isolates primarily belonged to clonal complex 23 (CC23), and this clonal lineage was revealed to be clearly distinct from nonhypervirulent strains. A specific virulence plasmid was found to be associated with hypervirulence, and novel genetic determinants uniquely associated with CC23 were identified. Our findings extend the understanding of the genetic background of the emergence of hvKP clones.
| S-EPMC4513082 | biostudies-literature
Project description:Klebsiella pneumoniae has been the predominant pathogen of liver abscess, but ST11-K47 carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) has rarely been studied as the causative organism. We identified an ST11-K47 CR-hvKP (HvKp-su1) from the drainage fluid of a liver abscess in a Chinese man who was diagnosed with liver abscess combined with diabetes, pneumonia, pleural infection, abdominal abscess, and splenic abscess. HvKp-su1 was non-hypermucoviscous and lacked the magA and rmpA genes and pLVPK plasmid but exhibited high virulence, with a high mortality rate (90%) to wax moth larvae (G. mellonella), similar to the hypervirulent Klebsiella pneumoniae ATCC43816 (91.67%). Whole-genome sequencing and bioinformatics analysis indicated that HvKp-su1 possesses a plasmid similar to a type of pLVPK-like plasmid (JX-CR-hvKP-2-P2), which is an uncommon plasmid in CR-hvKP. HvKp-su1 carried multiple resistance genes, including blaKPC-2. blaTEM-1, blaSHV-55, and blaCTX-M-65; hypervirulence genes such as aerobactin (iutA), salmochelin (iroEN), and yersiniabactin (ybtAEPQSTUX); and the type 3 fimbriae-encoding system (mrkACDF). Moreover, v_5377 and v_5429 (cofT, CFA/III (CS8)) located on plasmid 1 were simultaneously predicted to be virulence genes. After the long-term combination use of antibiotics, the patient successfully recovered. In summary, our study clarified the clinical and molecular characteristics of a rare ST11-K47 CR-hvKP (HvKp-su1), raising great concerns about the emergence of ST11-K47 CR-hvKP with multidrug resistance and hypervirulence, and providing insights into the control and treatment of liver abscess caused by ST11-K47 CR-hvKP.
| S-EPMC9227846 | biostudies-literature
Project description:BackgroundPlasmids play an vital role in driving the rapid global spread of antimicrobial resistance and adaptation to changing ambient conditions. It has been suggested that the presence of plasmids can pose tremendous impacts on the host physiology. However, little is known regarding the contributions of carbapenemase-encoding plasmid carriage on the physiology and pathogenicity of hypervirulent K. pneumoniae (hvKP).ResultsHere we performed a transcriptomic analysis of hvKP with or without carbapenemase-encoding plasmid p24835-NDM5. The results had shown 683 genes with differential expression (false discovery rate, ≤0.001; > 2-fold change), of which 107 were up-regulated and 576 were down-regulated. Gene groups with functions relating to carbohydrate metabolism and multidrug efflux system were increased in genes with increased expression, and those relating to capsule biosynthesis and virulence factors were increased in the genes with decreased expression. In agreement with these changes, survival rate of TfpNDM-hvKP in the presence of normal human serum decreased, and competitive index (CI values) indicated significant fitness defects in the plasmid-carrying hvKP strain when co-cultured with its plasmid-free isogenic ancestor and the ATCC control. Moreover, the p24835-NDM5-containing hvKP strain retained its high neutrophil-mediated phagocytosis and murine lethality.ConclusionThese data indicate that hvKP responds to carbapenemase-encoding plasmid by altering the expression of genes involved in carbohydrate metabolism, antibiotic resistance, capsule biosynthesis and virulence expression. Apart from antibiotic resistance selective advantages, carbapenemase-encoding plasmid carriage may also lead to virulence change or adaption to specific habitats in hvKP strain.
| S-EPMC6558890 | biostudies-literature