Klebsiella pneumoniae-induced liver abscesses, Germany.
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ABSTRACT:
SUBMITTER: Bilal S
PROVIDER: S-EPMC4214298 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Gastric microbiota provides a biological barrier against the invasion of foreign pathogens from the oral cavity, playing a vital role in maintaining gastrointestinal health. Klebsiella spp. of oral origin causes various infections not only in gastrointestinal tract but also in other organs, with Klebsiella pneumoniae serotype K1 resulting in a liver abscess (KLA) through oral inoculation in mice. However, the relationship between gastric microbiota and the extra-gastrointestinal KLA infection is not clear. In our study, a 454 pyrosequencing analysis of the bacterial 16S rRNA gene shows that the composition of gastric mucosal microbiota in mice with or without KLA infection varies greatly after oral inoculation with K. pneumoniae serotype K1 isolate. Interestingly, only several bacteria taxa show a significant change in gastric mucosal microbiota of KLA mice, including the decreased abundance of Bacteroides, Alisptipes and increased abundance of Streptococcus. It is worth noting that the abundance of Klebsiella exhibits an obvious increase in KLA mice, which might be closely related to KLA infection. At the same time, the endogenous antibiotics, defensins, involved in the regulation of the bacterial microbiota also show an increase in stomach and intestine. All these findings indicate that liver abscess caused by K. pneumoniae oral inoculation has a close relationship with gastric microbiota, which might provide important information for future clinical treatment.Gastric microbiota provides a biological barrier against the invasion of foreign pathogens from the oral cavity, playing a vital role in maintaining gastrointestinal health. Klebsiella spp. of oral origin causes various infections not only in gastrointestinal tract but also in other organs, with Klebsiella pneumoniae serotype K1 resulting in a liver abscess (KLA) through oral inoculation in mice. However, the relationship between gastric microbiota and the extra-gastrointestinal KLA infection is not clear. In our study, a 454 pyrosequencing analysis of the bacterial 16S rRNA gene shows that the composition of gastric mucosal microbiota in mice with or without KLA infection varies greatly after oral inoculation with K. pneumoniae serotype K1 isolate. Interestingly, only several bacteria taxa show a significant change in gastric mucosal microbiota of KLA mice, including the decreased abundance of Bacteroides, Alisptipes and increased abundance of Streptococcus. It is worth noting that the abundance of Klebsiella exhibits an obvious increase in KLA mice, which might be closely related to KLA infection. At the same time, the endogenous antibiotics, defensins, involved in the regulation of the bacterial microbiota also show an increase in stomach and intestine. All these findings indicate that liver abscess caused by K. pneumoniae oral inoculation has a close relationship with gastric microbiota, which might provide important information for future clinical treatment.
| S-EPMC7256812 | biostudies-literature
Project description:Purpose: To explore the metabolic characterization of host responses to drainage-resistant Klebsiella pneumoniae liver abscesses (DRKPLAs) with serum 1H-nuclear magnetic resonance (NMR) spectroscopy. Materials and Methods: The hospital records of all patients with a diagnosis of a liver abscess between June 2015 and December 2016 were retrieved from an electronic hospital database. Eighty-six patients with Klebsiella pneumoniae (K. pneumoniae) liver abscesses who underwent percutaneous drainage were identified. Twenty patients with confirmed DRKPLAs were studied. Moreover, we identified 20 consecutive patients with drainage-sensitive Klebsiella pneumoniae liver abscesses (DSKPLAs) as controls. Serum samples from the two groups were analyzed with 1H NMR spectroscopy. Partial least squares discriminant analysis (PLS-DA) was used to perform 1H NMR metabolic profiling. Metabolites were identified using the Human Metabolome Database, and pathway analysis was performed with MetaboAnalyst 3.0. Results: The PLS-DA test was able to discriminate between the two groups. Five key metabolites that contributed to their discrimination were identified. Glucose, lactate, and 3-hydroxybutyrate were found to be upregulated in DRKPLAs, whereas glutamine and alanine were downregulated compared with the DSKPLAs. Pathway analysis indicated that amino acid metabolisms were significantly different between the DRKPLAs and the DSKPLAs. The D-glutamine and D-glutamate metabolisms exhibited the greatest influences. Conclusions: The five key metabolites identified in our study may be potential targets for guiding novel therapeutics of DRKPLAs and are worthy of additional investigation.
| S-EPMC5992471 | biostudies-literature
Project description:BackgroundThere is a dearth of information on liver abscesses in the United Arab Emirates. Herein, we describe the clinical features of liver abscesses and determine their incidence rates and clinical outcomes.MethodsWe retrospectively reviewed the clinical charts of adult patients with a primary diagnosis of liver abscess at a major hospital over a 7-year period.ResultsAmongst 45 patients, 82.2% (37/45) had a pyogenic liver abscess (PLA) and 17.8% (8/45) had amoebic liver abscesses (ALA). Overall, patients were young (median age 42 years, IQR 35-52), mostly males (77.8%, 35/45) from the Indian subcontinent (55.6%, 25/45), presented with fever (88.9%, 40/45) and abdominal pain (88.9%, 40/45), and had a solitary abscess on imaging (71.1% (32/45). Crude annual incidence rates were 35.9/100,000 hospital admissions (95% CI 26.2-48.0) and 5.9/100,000 inhabitants (95% CI 4.3-7.9). All ALA patients were from the Indian subcontinent (100%, 8/8). Klebsiella pneumoniae was the most frequent pathogen in PLA (43.2% [16/37], 95% CI 27.1-60.5%). The hospital stay was shorter in ALA (7.5 days, IQR 7-8.5) than in PLA (14 days, IQR 9-17). No deaths were recorded within 30 days of hospitalisation.ConclusionsALA was exclusively seen in migrants from the Indian subcontinent, suggesting importation. Further research to characterise K. pneumoniae isolates and assess potential risk factors is needed.
| S-EPMC8196433 | biostudies-literature
Project description:Klebsiella pneumoniae is the predominant pathogen of primary liver abscess. However, our knowledge regarding the molecular basis of how K. pneumoniae causes primary infection in the liver is limited. We established an oral infection model that recapitulated the characteristics of liver abscess and conducted a genetic screen to identify the K. pneumoniae genes required for the development of liver abscess in mice. Twenty-eight mutants with attenuated growth in liver or spleen samples out of 2,880 signature-tagged mutants that produced the wild-type capsule were identified, and genetic loci which were disrupted in these mutants were identified to encode products with roles in cellular metabolism, adhesion, transportation, gene regulation, and unknown functions. We further evaluated the virulence attenuation of these mutants in independent infection experiments and categorized them accordingly into three classes. In particular, the class I and II mutant strains exhibited significantly reduced virulence in mice, and most of these strains were not detected in extraintestinal tissues at 48 h after oral inoculation. Interestingly, the mutated loci of about one-third of the class I and II mutant strains encode proteins with regulatory functions, and the transcript abundances of many other genes identified in the same screen were markedly changed in these regulatory mutant strains, suggesting a requirement for genetic regulatory networks for translocation of K. pneumoniae across the intestinal barrier. Furthermore, our finding that preimmunization with certain class I mutant strains protected mice against challenge with the wild-type strain implied a potential application for these strains in prophylaxis against K. pneumoniae infections.
| S-EPMC2708586 | biostudies-literature
Project description:Klebsiella pneumoniae-induced liver abscess (KLA) is emerging as a leading cause of pyogenic liver abscess worldwide. In recent years, the emergence of hypervirulent K. pneumoniae (hvKp) has been strongly associated with KLA. Unlike classical K. pneumoniae, which generally infects the immunocompromised population, hvKp can cause serious and invasive infections in young and healthy individuals. hvKp isolates are often associated with the K1/K2 capsular types and possess hypermucoviscous capsules. KLA is believed to be caused by K. pneumoniae colonizing the gastrointestinal tract of the host and translocating across the intestinal barrier via the hepatic portal vein into the liver to cause liver abscess. We optimized the isolation of the liver-resident macrophages called Kupffer cells in mice and examined their importance in controlling bacterial loads during hvKp infection in healthy mice. Our study reveals the high capability of Kupffer cells to kill hvKp in vitro despite the presence of the bacterial hypermucoviscous capsule, in contrast to other macrophages, which were unable to phagocytose the bacteria efficiently. Depletion of Kupffer cells and macrophages with liposome-encapsulated clodronate (liposomal clodronate) in both an intraperitoneal and an oral mouse infection model resulted in increased bacterial loads in the livers, spleens, and lungs and increased mortality of the infected mice. Thus, Kupffer cells and macrophages are critical for the control of hvKp infection.
| S-EPMC6704610 | biostudies-literature
Project description:Background: Multidrug-resistant bacteria, especially those with high virulence, are an emerging problem in clinical settings.Methods: We conducted a multicentre epidemiological and comparative genomic analysis on the evolution, virulence and antimicrobial resistance of carbapenem-resistant Enterobacteriaceae in patients with bacterial liver abscesses from 2012 to 2016.Results: A total of 477 bacterial isolates were collected. Enterobacteriaceae were the main pathogen (89.3%) with K. pneumoniae (52.4%) predominating followed by Escherichia coli (26.8%). All CRKps (3.2%) were of sequence type (ST) 11 and serotypes K47 or K64, and simultaneously possessed acquired blaKPC-2/blaKPC-5 and blaCTX-M-65 together with the multidrug transporter EmrE. Seven Hv-CRKps (five ST11-K47, two ST11-K64) were confirmed by bacteriological test, neutrophil killing assay and Galleria mellonella infection model. Genomic analysis indicated that the emergence of one ST11-K64 Hv-CRKp strain was related to the acquisition of rmpA/rmpA2 genes and siderophore gene clusters, while ST11-K47 Hv-CRKp lacked these traditional virulence genes. Further complete genome analysis of one ST11-K47 Hv-CRKp strain, R16, showed that it acquired a rare plasmid (pR16-Hv-CRKp1) carrying blaKPC-2, blaSHV-12, blaTEM-1, blaCTX-M-65, rmtB and a predicted virulence gene R16_5486 simultaneously.Conclusion: The emergence of the ST11-K47/K64 Hv-CRKps, which are simultaneously multidrug-resistant and hypervirulent, requires urgent control measures to be implemented.
| S-EPMC7034084 | biostudies-literature
Project description:To determine the role of gastrointestinal carriage in Klebsiella pneumoniae liver abscess, we studied 43 patients. Bacterial isolates from liver and fecal samples from 10 patients with this condition and 7 healthy carriers showed identical serotypes and genotypes with the same virulence. This finding indicated that gastrointestinal carriage is a predisposing factor for liver abscess.
| S-EPMC3414011 | biostudies-literature
Project description:We report a case of severe infection with liver abscess and endophthalmitis caused by a hypervirulent Klebsiella pneumoniae strain in an immunocompetent German male patient without travel history to Asia. Phenotypic and molecular characterization showed high similarity to the reference genome NTUH-K2044 isolated in Asia. The isolate was assigned as ST2398 (clonal complex 66). The findings underline global spread of hypervirulent Klebsiella pneumoniae strains to Europe.
| S-EPMC5376316 | biostudies-literature
Project description:Taiwan has witnessed an emerging syndrome of liver abscess caused by Klebsiella pneumoniae carrying the magA gene required for exopolysaccharide web biosynthesis. We report a patient transferred from Alaska to Washington State with a magA(+) K. pneumoniae liver abscess and describe a simple approach for recognition of these hypervirulent strains.
| S-EPMC548117 | biostudies-literature
Project description:The outcome of an infection depends on host recognition of the pathogen, hence leading to the activation of signaling pathways controlling defense responses. A long-held belief is that the modification of the lipid A moiety of the lipopolysaccharide could help Gram-negative pathogens to evade innate immunity. However, direct evidence that this happens in vivo is lacking. Here we report the lipid A expressed in the tissues of infected mice by the human pathogen Klebsiella pneumoniae. Our findings demonstrate that Klebsiella remodels its lipid A in a tissue-dependent manner. Lipid A species found in the lungs are consistent with a 2-hydroxyacyl-modified lipid A dependent on the PhoPQ-regulated oxygenase LpxO. The in vivo lipid A pattern is lost in minimally passaged bacteria isolated from the tissues. LpxO-dependent modification reduces the activation of inflammatory responses and mediates resistance to antimicrobial peptides. An lpxO mutant is attenuated in vivo thereby highlighting the importance of this lipid A modification in Klebsiella infection biology. Colistin, one of the last options to treat multidrug-resistant Klebsiella infections, triggers the in vivo lipid A pattern. Moreover, colistin-resistant isolates already express the in vivo lipid A pattern. In these isolates, LpxO-dependent lipid A modification mediates resistance to colistin. Deciphering the lipid A expressed in vivo opens the possibility of designing novel therapeutics targeting the enzymes responsible for the in vivo lipid A pattern.
| S-EPMC4655541 | biostudies-literature