Citrobacter

Citrobacter is a genus of Gram-negative enteric bacteria. It include Citrobacter rodentium whose cognate host is mice where it causes transmissible murine colonic hyperplasia, and is responsible for high mortality in suckling mice (Barthold et al., 1978; Schauer & Falkow, 1993; Schauer et al., 1995). Citrobacter species are widely distributed in nature, frequently present in soil and water, and can be readily isolated from human and animal faeces. However, unlike the host-adapted C. rodentium that causes gastrointestinal disease, the other Citrobacter species are opportunistic pathogens that cause a variety of extraintestinal infections (Luperchio & Schauer, 2001). Although disease caused by C. rodentium has been observed primarily in mice, this bacterium has also been reported to cause disease with a high rate of fatality in other rodents (de la Puente-Redondo et al., 1999). There are no reports of C. rodentium being pathogenic to humans.

Data downloads

• FTP site
• Citrobacter rodentium BLAST server
• Citrobacter freundii BLAST server

Citrobacter rodentium

C. rodentium is a member of the attaching and effacing (A/E) family of bacterial pathogens, which is characterised by intimate bacterial adherence to host intestinal epithelial cells, effacement of microvilli, and reorganisation of the host actin cytoskeleton to form pedestal-like extensions of epithelial cells beneath the adherent bacteria called A/E lesions (Wales et al., 2005). Gastrointestinal colonisation and formation of A/E lesions is mediated by a pathogenicity island called the locus of enterocyte effacement (LEE), which is conserved among A/E bacteria (Deng et al., 2001; Wales et al., 2005). C. rodentium is unique amongst Citrobacter species in possessing the LEE (Schauer & Falkow, 1993; Schauer et al., 1995). As the only known A/E pathogen to naturally infect mice, it is a valuable model organism for the study of pathogenesis of the clinically significant human pathogens, enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC).

Collaborators

Gad Frankel Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK.

Nicola Petty School of Chemistry and Molecular Biosciences University of Queensland Brisbane QLD 4072 Australia

Published Data

We have reported the fully annotated genome sequence of a murine virulent strain of C. rodentium, ICC168. The genome is 5,346,659 bp in length, with an average G+C content of 54.72 % and is deposited in the EMBL/GenBank databases with accession number FN543502. Additionaly, three plasmids are also deposited in EMBL/GenBank with accession numbers FN543503, FN543504 and FN543505.

Shotgun and assembly data from this project are available from our FTP site.

Citrobacter freundii

The Sanger Institute has been funded by the Wellcome Trust to sequence the genome of Citrobacter freundii ballerup 7851.

The DNA sequence of Citrobacter freundii ballerup 7851 was obtained by 454 FLX pyrosequencing, assembled using the 454/Roche Newbler assembly program.

357 contigs (N50 contig size 60,237 bp) were obtained from 410,057 sequence reads with an average read length of 177 bp, to give a total sequence length of 4,904,659 bp. The data are available in the European Nucleotide Archive with accession ERA000106.

Related links

• Artemis
• Bacteria
• Citrobacter freundii
• Citrobacter rodentium
• CMMI
• European Nucleotide Archive (C. freundii)
• WTSI Sequencing

Data Use Statement

This sequencing centre plans on publishing the completed and annotated sequences in a peer-reviewed journal as soon as possible. Permission of the principal investigator should be obtained before publishing analyses of the sequence/open reading frames/genes on a chromosome or genome scale. See our data sharing policy.

Sequencing enquiries

Please address all sequencing enquiries to: pathinfo@sanger.ac.uk