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Genetic
diversity of Campylobacter jejuni
Abstract:
Campylobacter jejuni is
one of the most common causes of bacterial diarrhea worldwide. It
is also the primary bacterial cause of food-borne illness.
Variability in the clinical symptoms of Campylobacter infection
has been observed for many years. The clinical picture ranges from
asymptomatic infection to secretory diarrhea and, less frequently,
inflammatory diarrhea. Other clinical presentations of Campylobacter
infection are maningitis, bacteremia, localized
extraintestinal infections, and immunoreactive complication such
as Guillain-Barrć syndrome and reactive arthritis. variability of
the infection symptoms and the phenotypic traits of isolates may
be related to genetic diversity of Campylobacter strains.
The diversity within C. jejuni isolates has been well
established and is detectable at both, the phenotypic and
genotypic level. The lack of the genetic, physiological and
pathogenic information of this pathogen was the driving force
behind the C. jejuni NCTC 11168 genome project.
Completion of genome sequence offers unrivalled opportunities to
understand the molecular basis of virulence of this pathogen
and revealed a few mechanisms by which the organism can
generate genetic diversity. Among a lot of novel features revealed
by the genome sequence are at least 25 hypervariable sequences
mostly found in genes encoding surface structures. Variation of
the length of poly G/C tracts in genes containing these
hypervariable sequences is likely to play a key role in enabling C. jejuni
to evade the host immune response. The ability of the C. jejuni
genome sequence data has coincided with important
technological advances in bioinformatics, gene mutagenesis,
proteome analysis and DNA microarrays. Given the range of disease
associated with C. jejuni infection, combined
with the diverse genotyping and phenotypic properties of clinical
and environmental isolates, a Campylobacter DNA
microarray will be particularly useful in determining
correlates of pathogenicity and in deciphering the epidemiology of
the microorganism.
1. Introduction.
2. Basic features of the genome sequence of C. jejuni
NCTC 11168. 3. Typing of Campylobacter spp.
3.1. Fenotyping. 3.1.1. Serotyping. 3.1.2. Biotyping.
3.2. Genotyping. 4. Genetic diversity of Campylobacter
spp. 4.1. Facts improving genetic diversity of C. jejuni.
4.2. Mechanisms of genetic diversity of C. jejuni.
5. Summary
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