The genome sequence of the food-borne pathogen Campylobacter jejuni reveals hypervariable sequences

Abstract

Campylobacter jejuni, from the delta-epsilon group of proteobacteria, is a microaerophilic, Gram-negative, flagellate, spiral bacterium-properties it shares with the related gastric pathogen Helicobacter pylori. It is the leading cause of bacterial food-borne diarrhoeal disease throughout the world. In addition, infection with C. jejuni is the most frequent antecedent to a form of neuromuscular paralysis known as Guillain-Barré syndrome. Here we report the genome sequence of C. jejuni NCTC11168. C. jejuni has a circular chromosome of 1,641,481 base pairs (30.6% G+C) which is predicted to encode 1,654 proteins and 54 stable RNA species. The genome is unusual in that there are virtually no insertion sequences or phage-associated sequences and very few repeat sequences. One of the most striking findings in the genome was the presence of hypervariable sequences. These short homopolymeric runs of nucleotides were commonly found in genes encoding the biosynthesis or modification of surface structures, or in closely linked genes of unknown function. The apparently high rate of variation of these homopolymeric tracts may be important in the survival strategy of C. jejuni.

An alternative menaquinone biosynthetic pathway operating in microorganisms: an attractive target for drug discovery to pathogenic Helicobacter and Chlamydia strains

“…17 Among them, we found that some microorganisms belonging to the epsilon and delta categories in Proteobacteria, such as H. pylori, Wolinella succinogenes, C. jejuni and Geobacter sulfurreducens, a part of actinobacteria, such as S. coelicolor and S. avermitilis, and certain Deinococcus-Thermus bacteria, such as Thermus thermophilus and Deinococcus radioduran and so on, had no men gene orthologs despite the fact that these strains synthesize MKs. Among them, we selected four microorganisms, H. pylori, 13 C. jejuni, 14 T. thermophilus 18 and S. coelicolor, 11 as query microorganisms. With regard to subject microorganisms, in which the known MK biosynthetic pathway was operating, E. coli, 19 B. subtilis, 20 Corynebacterium glutamicum 21 and Mycobacterium tuberculosis 22 were selected.…”

“…11,12 Some pathogenic microorganisms, such as Helicobacter pylori 13 and Campylobacter jejuni, 14 which are known to cause gastric carcinoma and diarrhea, respectively, also lacked these five men gene orthologs, although they synthesize MK. 15,16 In contrast, these microorganisms possessed orthologs of menA and menG, 13,14 which catalyze a prenylation and a methylation, respectively, suggesting that the naphthoquinone moiety of MK would be synthesized through an alternative pathway.…”

Detection of fluoroquinolone resistance by mutation in gyrA gene of Campylobacter spp. isolates from broiler and laying (Gallus gallus domesticus) hens,from Rio de Janeiro State, Brazil

“…For sequencing, PCR was performed with specific primers for amplification of QRDR in the gyrA gene, CjgyrA QRDR F and CjgyrA QRDR R (PARKHILL et al, 2000;PRICE et al, 2005). The Invitrogen kit (Life Technologies/USA) was used for the reaction, with 1X PCR Buffer (500mM KCl, 100mM Tris-HCl [pH 9.0]); 5μL (1mM each) dATP, dCTP, dGTP e dTTP; 0.5μL from each primer, 1.0U Taq DNA polymerase and 2mM MgCl 2 .…”

Contribution of the stereospecific methionine sulphoxide reductases MsrA and MsrB to oxidative and nitrosative stress resistance in the food-borne pathogen Campylobacter jejuni

“…C. jejuni is a commensal in many bird species, including poultry, and contaminated chicken meat is a major source of infection (Ketley, 1997). The genome sequence of C. jejuni strain NCTC 11168 was published in 2000 (Parkhill et al, 2000), and several other strains have been recently sequenced including strains 81116 (Pearson et al, 2007) and 81-176 (Hofreuter et al, 2006). Oxidative and nitrosative stresses are major factors that pathogens must combat in order to survive both outside and inside the host.…”