Cited by 181Escherichia coli research studiesAntibiotic Resistance in BacteriaEnterobacteriaceae and Cronobacter Research

The DOI matches its Crossref record; 88 of the 88 references it cites were found in a registry or an index.

Comparative analysis of Klebsiella pneumoniae genomes identifies a phospholipase D family protein as a novel virulence factor

Open access

Abstract

BACKGROUND: Klebsiella pneumoniae strains are pathogenic to animals and humans, in which they are both a frequent cause of nosocomial infections and a re-emerging cause of severe community-acquired infections. K. pneumoniae isolates of the capsular serotype K2 are among the most virulent. In order to identify novel putative virulence factors that may account for the severity of K2 infections, the genome sequence of the K2 reference strain Kp52.145 was determined and compared to two K1 and K2 strains of low virulence and to the reference strains MGH 78578 and NTUH-K2044. RESULTS: In addition to diverse functions related to host colonization and virulence encoded in genomic regions common to the four strains, four genomic islands specific for Kp52.145 were identified. These regions encoded genes for the synthesis of colibactin toxin, a putative cytotoxin outer membrane protein, secretion systems, nucleases and eukaryotic-like proteins. In addition, an insertion within a type VI secretion system locus included sel1 domain containing proteins and a phospholipase D family protein (PLD1). The pld1 mutant was avirulent in a pneumonia model in mouse. The pld1 mRNA was expressed in vivo and the pld1 gene was associated with K. pneumoniae isolates from severe infections. Analysis of lipid composition of a defective E. coli strain complemented with pld1 suggests an involvement of PLD1 in cardiolipin metabolism. CONCLUSIONS: Determination of the complete genome of the K2 reference strain identified several genomic islands comprising putative elements of pathogenicity. The role of PLD1 in pathogenesis was demonstrated for the first time and suggests that lipid metabolism is a novel virulence mechanism of K. pneumoniae.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1186/1741-7007-12-41

Cites

88 of 88 references verified0 citation errors · 0 not checkable

Statistics

Figures

Figure 1 K. pneumoniae Kp52.145 genome. A) Chromosome representation: Outermost layers in gray indicate the position of positive and negative strand CDSs. tRNAs are represented in green, while the four virulence-related genomic islands (GI) are in red, the locus coding for anaerobic metabolism in orange, the T6SS gene clusters in blue and capsular synthesis region in yellow. Inner circle represents G + C%. Detail of the T6SS locus III region containing the putative phospholipase (pld1 gene) (orange) and sel1 (pink) genes is shown enlarged. B) Plasmids representation: plasmid maintenance genes and IS sequences are shown in blue, proteins with unknown functions in gray, known functions in green, toxin-antitoxin systems in yellow and rmpA in red. CDSs, coding sequences.
Figure 1 K. pneumoniae Kp52.145 genome. A) Chromosome representation: Outermost layers in gray indicate the position of positive and negative strand CDSs. tRNAs are represented in green, while the four virulence-related genomic islands (GI) are in red, the locus coding for anaerobic metabolism in orange, the T6SS gene clusters in blue and capsular synthesis region in yellow. Inner circle represents G + C%. Detail of the T6SS locus III region containing the putative phospholipase (pld1 gene) (orange) and sel1 (pink) genes is shown enlarged. B) Plasmids representation: plasmid maintenance genes and IS sequences are shown in blue, proteins with unknown functions in gray, known functions in green, toxin-antitoxin systems in yellow and rmpA in red. CDSs, coding sequences.CC BY · PubMed Central
Figure 2 Genomic islands (GIs) identified in the genome of Kp52.145. Positive and negative strand CDSs are represented in gray. Putative virulence related genes are highlighted in different colors. The size of each GI is given in kb. Panel A: GI-I, B: GI-II, C: GI-III and D: GI-IV. CDS, coding sequences.
Figure 2 Genomic islands (GIs) identified in the genome of Kp52.145. Positive and negative strand CDSs are represented in gray. Putative virulence related genes are highlighted in different colors. The size of each GI is given in kb. Panel A: GI-I, B: GI-II, C: GI-III and D: GI-IV. CDS, coding sequences.CC BY · PubMed Central
Figure 3 Sequence alignment of Kp52.145 (Kp) PLD1 and its closest related sequences: putative phospholipase D family protein from Pseudomonas syringae (PS) and cardiolipin synthases from P. putida (PP), Staphylococcus aureus (SA), Bacilus subtilis (BS) and E. coli (EC). The rectangles indicate the phospholipase D active site regions and the asterisk points to the corresponding transposon insertion site in pld1 mutant strain.
Figure 3 Sequence alignment of Kp52.145 (Kp) PLD1 and its closest related sequences: putative phospholipase D family protein from Pseudomonas syringae (PS) and cardiolipin synthases from P. putida (PP), Staphylococcus aureus (SA), Bacilus subtilis (BS) and E. coli (EC). The rectangles indicate the phospholipase D active site regions and the asterisk points to the corresponding transposon insertion site in pld1 mutant strain.CC BY · PubMed Central
Figure 4 PLD1 involvement in K. pneumoniae virulence. Mice survival after infection with K. pneumoniae Kp52.145 wild-type, pld1 mutant and complemented strains. Data are representative of seven mice per group from two independent experiments. Standard deviation is shown. PLD, phospholipase D.
Figure 4 PLD1 involvement in K. pneumoniae virulence. Mice survival after infection with K. pneumoniae Kp52.145 wild-type, pld1 mutant and complemented strains. Data are representative of seven mice per group from two independent experiments. Standard deviation is shown. PLD, phospholipase D.CC BY · PubMed Central
Figure 5 PLD1 involvement in lipids metabolism. A) TLC lipid profiles of E. coli strain SD9 and SD9 + pPLD. Red circle indicates phosphatidyl glycerol. Blue circle represents the lipid present specifically upon pld1 expression. B) Mass spectrometry profiles of E. coli strain SD9 and SD9 + pPLD lipids. The red arrow points to m/z 789.4 exclusively found in wild-type strain. TLC, thin-layer chromatography.
Figure 5 PLD1 involvement in lipids metabolism. A) TLC lipid profiles of E. coli strain SD9 and SD9 + pPLD. Red circle indicates phosphatidyl glycerol. Blue circle represents the lipid present specifically upon pld1 expression. B) Mass spectrometry profiles of E. coli strain SD9 and SD9 + pPLD lipids. The red arrow points to m/z 789.4 exclusively found in wild-type strain. TLC, thin-layer chromatography.CC BY · PubMed Central

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Show all 88 references

Cited by

Sorted by citations

See all 181

Metadata

Authors
Lery, L. M., Frangeul, L., Tomas, A., Passet, V., Almeida, A. S., Bialek-Davenet, S., Barbe, V., Bengoechea, J. A., Sansonetti, P., Brisse, S., & Tournebize, R.
Affiliations
  • Institut Pasteur (FR)
  • Centre National de la Recherche Scientifique (FR)
  • Inserm (FR)
  • Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
  • Queen's University Belfast (GB)
Corresponding author
Tournebize, Régis
Venue
BMC Biology
Published
2014-05-29
Volume
12
Issue
1
Pages
41-41
ISSN
1741-7007 (ISSN-L)
OpenAlex
W2129183301
Cited by
181
References
88
Citations by year
2026: 8 · 2025: 8 · 2024: 12 · 2023: 15 · 2022: 37 · 2021: 11 · 2020: 21 · 2019: 14 · 2018: 15 · 2017: 10 · 2016: 9 · 2015: 15 · 2014: 5
FWCI
9.16
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • BMC Biology (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Research Portal (Queen's University Belfast) (acceptedVersion, other-oa)
  • HAL (submittedVersion, other-oa)
  • Docusalut (Conselleria de Salut i Consum del Govern de les Illes Balears) (submittedVersion, cc-by)
  • Hispana (submittedVersion, cc-by)
Funders
Fundação para a Ciência e a Tecnologia
Topics
  • Life Sciences › Immunology and Microbiology › Microbiology › Escherichia coli research studies
  • Health Sciences › Medicine › Microbiology (medical) › Antibiotic Resistance in Bacteria
  • Life Sciences › Immunology and Microbiology › Microbiology › Enterobacteriaceae and Cronobacter Research
Keywords
Klebsiella pneumoniae, virulence factors, phospholipase D, phospholipase D1, genomic islands, type VI secretion system, cardiolipin metabolism, lipid metabolism, bacterial pathogenesis, comparative genomics
MeSH terms
Amino Acid Sequence, Animals, Bacterial Proteins, Genes, Bacterial, Multigene Family, Klebsiella pneumoniae, Molecular Sequence Data, Phospholipase D, Plasmids, Virulence, Mutagenesis, Insertional, Sequence Alignment, Genome, Bacterial, Virulence Factors, Genomic Islands, Lipid Metabolism, Mice, Bacterial Secretion Systems, Molecular Sequence Annotation

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review