Phase variation and microevolution at homopolymeric tracts in Bordetella pertussis

Gogol, Emily; Cummings, Craig; Burns, Ryan C; Relman, David A.

doi:10.1186/1471-2164-8-122

Cited by 27 publications

(38 citation statements)

References 51 publications

(74 reference statements)

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“…The genome of the derived species, pertussis and parapertussis , has a smaller size than their ancestor with a considerable increase in the number of IS elements, pseudogenes and many chromosomal rearrangements more particularly for B. pertussis . It was also recently shown that allelic polymorphism at homopolymeric tracts is common within the B. pertussis genome [16]. This polymorphism could play a role in the adaptation of B. pertussis to the Human host but could also play a role for evasion of the immune system.…”

Section: Discussionmentioning

confidence: 98%

Genomic Content of Bordetella pertussis Clinical Isolates Circulating in Areas of Intensive Children Vaccination

et al. 2008

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BackgroundThe objective of the study was to analyse the evolution of Bordetella pertussis population and the influence of herd immunity in different areas of the world where newborns and infants are highly vaccinated.MethodologyThe analysis was performed using DNA microarray on 15 isolates, PCR on 111 isolates as well as GS-FLX sequencing technology on 3 isolates and the B. pertussis reference strain, Tohama I.Principal FindingsOur analyses demonstrate that the current circulating isolates are continuing to lose genetic material as compared to isolates circulating during the pre-vaccine era whatever the area of the world considered. The lost genetic material does not seem to be important for virulence. Our study confirms that the use of whole cell vaccines has led to the control of isolates that were similar to vaccine strains. GS-FLX sequencing technology shows that current isolates did not acquire any additional material when compared with vaccine strains or with isolates of the pre-vaccine era and that the sequenced strain Tohama I is not representative of the isolates. Furthermore, this technology allowed us to observe that the number of Insertion Sequence elements contained in the genome of the isolates is temporally increasing or varying between isolates.Conclusions B. pertussis adaptation to humans is still in progress by losing genetic material via Insertion Sequence elements. Furthermore, recent isolates did not acquire any additional material when compared with vaccine strains or with isolates of the pre-vaccine era. Herd immunity, following intensive vaccination of infants and children with whole cell vaccines, has controlled isolates similar to the vaccine strains without modifying significantly the virulence of the isolates. With the replacement of whole cell vaccines by subunit vaccines, containing only few bacterial antigens targeting the virulence of the bacterium, one could hypothesize the circulation of isolates expressing less or modified vaccine antigens.

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Section: Discussionmentioning

confidence: 98%

Genomic Content of Bordetella pertussis Clinical Isolates Circulating in Areas of Intensive Children Vaccination

et al. 2008

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“…In addition, evidence from clinical studies may suggest that the Fim antigens are perhaps being subjected to immune selection due to vaccine-induced and natural-antibody-driven adaptation (Gogol et al, 2007;Tsang et al, 2004). The sophisticated controls used by B. pertussis to regulate virulence genes (differential binding of the BvgA~P activator to the promoters, different RNAP/activator architectures and phase variation by programmed mutation) demonstrate how a pathogen that is highly clonal and lacks the genetic diversity of many other pathogens can be quite successful as an obligate human pathogen (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…One benefit of phase variation is that it allows an organism to create diversity in an otherwise clonal population -a valuable trait for B. pertussis which has unusually poor genomic diversity for a pathogen (Gogol et al, 2007). Phenotypic diversity among surface-exposed adhesins is no doubt important for evading the host surveillance system and may be important to ensure some bacteria are poised to move to a new environment through detachment and shedding (Dybvig, 1993;Henderson et al, 1999).…”

Section: Phase Variation In the Fim Genes Generates Phenotypic Diversmentioning

confidence: 99%

The Bordetella pertussis model of exquisite gene control by the global transcription factor BvgA

et al. 2012

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“…The LDR products are separated in capillaries and the ligation occurrence is visible due to the band-shift. The use of various probe sets simultaneously is still possible and the ligated probes can be separated with a one base pair resolution [17,46]. This approach can be cost effective, but when the simultaneous visualization of many different DNA species or a higher sensitivity is needed UAs are more convenient.…”

Section: Ligation Detection Reaction-universal Arrays (Ldr-ua)mentioning

confidence: 99%

Potentials and limitations of molecular diagnostic methods in food safety

Lauri

Mariani

2008

Genes Nutr

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Molecular methods allow the detection of pathogen nucleic acids (DNA and RNA) and, therefore, the detection of contamination in food is carried out with high selectivity and rapidity. In the last 2 decades molecular methods have accompanied traditional diagnostic methods in routine pathogen detection, and might replace them in the upcoming future. In this review the implementation in diagnostics of four of the most used molecular techniques (PCR, NASBA, microarray, LDR) are described and compared, highlighting advantages and limitations of each of them. Drawbacks of molecular methods with regard to traditional ones and the difficulties encountered in pathogen detection from food or clinical specimen are also discussed. Moreover, criteria for the choice of the target sequence for a secure detection and classification of pathogens and possible developments in molecular diagnostics are also proposed.

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Phase variation and microevolution at homopolymeric tracts in Bordetella pertussis

Cited by 27 publications

References 51 publications

Genomic Content of Bordetella pertussis Clinical Isolates Circulating in Areas of Intensive Children Vaccination

Genomic Content of Bordetella pertussis Clinical Isolates Circulating in Areas of Intensive Children Vaccination

The Bordetella pertussis model of exquisite gene control by the global transcription factor BvgA

Potentials and limitations of molecular diagnostic methods in food safety

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