Biomedical subjects

Nicole Guiso

Publications and source records attributed to Nicole Guiso.

25 records · Page 2Linked to original sources

PubMed2003

PFGE and pertactin gene sequencing suggest limited genetic variability within the Finnish Bordetella parapertussis population.

The outer-membrane protein pertactin (Prn) of Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica is believed to function as an adhesin and is an important immunogen. The emergence of B. pertussis and B. bronchiseptica Prn variants has been reported. The aim of this study was to determine whether similar variation is found in B. parapertussis Prn and to characterize Finnish clinical B. parapertussis isolates that were collected in 1982-2000. Of 76 B. parapertussis isolates studied, seven (9 %) were found to have silent and non-silent nucleotide changes. In addition, one (1 %) had eight PQP repeats instead of nine. Three closely related B. parapertussis XbaI PFGE patterns were found. Genetic variation of B. parapertussis was found to be very limited, suggesting that B. parapertussis is a stable organism that is well-adapted to its own ecological niche.

Bacterial Outer Membrane Proteins↗

PubMed2003

Bordetella bronchiseptica persists in the nasal cavities of mice and triggers early delivery of dendritic cells in the lymph nodes draining the lower and upper respiratory tract.

Early after the intranasal instillation of Bordetella bronchiseptica into mice, not only are mature dendritic leukocytes recovered from lung parenchyma and bronchoalveolar lavage fluid but their numbers are also increased in the mediastinal lymph nodes and the nasal mucosa-associated lymphoid tissue. Later during the infectious process, the bacteria persist mainly in the nasal cavity.

Animals↗

PubMed2003

Comparison of the Bordetella pertussis and Bordetella parapertussis isolates circulating in Saint Petersburg between 1998 and 2000 with Russian vaccine strains.

We analyzed the Bordetella pertussis and Bordetella parapertussis isolates circulating in Saint Petersburg that were collected between 1998 and 2000 and compared them with isolates collected 40 years ago and Russian vaccine strains. The analysis involved serotyping, pulsed-field gel electrophoresis of chromosomal DNA after digestion with XbaI and SpeI, and sequencing of the ptxS1 and prn genes, which encode the S1 subunit of the pertussis toxin and the major adhesin pertactin, respectively. The Russian isolates were classified in five of the six pulsed-field gel electrophoresis groups identified in other European countries. The B. pertussis isolates currently circulating in Saint Petersburg differed from the Russian whole-cell vaccine strains and the isolates collected in the prevaccine era. However, their repartition in the major pulsed-field gel electrophoresis groups was slightly different from that of isolates collected in countries that have had a high level of vaccine coverage for a long time, probably because the level of vaccine coverage in Saint Petersburg has increased only recently, after decreasing until the early 1990s. Most of the B. parapertussis isolates studied were similar to those circulating in France. However, some variants were observed, perhaps because B. parapertussis infections are more common in children in this area.

Adenylyl Cyclases↗

PubMed2002

Evidence of Bordetella pertussis infection in adults presenting with persistent cough in a french area with very high whole-cell vaccine coverage.

Although France has had a vaccination program for 40 years, since 1990, an increase in whooping cough cases with parent-infant transmission has been observed. This study prospectively assessed the frequency of Bordetella pertussis infection in adults who consulted general practitioners for a persistent cough without an evident diagnosis. Among 217 patients, 70 (32%) confirmed whooping cough cases were identified. One case was culture positive, 36 were polymerase chain reaction positive, and 40 had increases or decreases of > or =2-fold in anti-pertussis toxin IgG titer between serum samples collected during the acute and convalescent phases. The median duration of cough in confirmed cases was 49 days (range, 13-123 days). Of the patients, 60% reported vaccination, and 33% reported whooping cough in infancy. Pertussis should be considered for diagnosis of acute and chronic cough in adults. Future studies should evaluate the public health interest of booster doses of pertussis vaccine in adults.

Adolescent↗

PubMed2002

Thirty-five years' experience with the whole-cell pertussis vaccine in France: vaccine strains analysis and immunogenicity.

A resurgence in infant and adult pertussis cases has been observed in many countries around 25 years after the introduction of generalised vaccination. An antigenic differences between circulating isolates and vaccinal strains, due to changes in vaccine procedures, could be due to this resurgence. In this study, we analysed the genome and antigenic expression of vaccinal strains of the Aventis Pasteur whole-cell pertussis vaccine from multiple lots stored since 1984. Despite lyophilisation having been performed on these strains for over 30 years, their genome remain conserved, and they still express the major toxins and adhesins. A study in mice confirmed that vaccine lots were highly immunogenic. In conclusion, there is no evidence to suggest that many years of production have resulted in alteration in the French vaccinal strains which quality has remained consistent since its introduction, this can explain its continued efficacy, effectiveness and the lack of epidemics in France.

Adhesins, Bacterial↗

PubMed2002

In vitro and in vivo characterization of a Bordetella bronchiseptica mutant strain with a deep rough lipopolysaccharide structure.

Bordetella bronchiseptica is closely related to Bordetella pertussis, which produces respiratory disease primarily in mammals other than humans. However, its importance as a human pathogen is being increasingly recognized. Although a large amount of research on Bordetella has been generated regarding protein virulence factors, the participation of the surface lipopolysaccharide (LPS) during B. bronchiseptica infection is less understood. To get a better insight into this matter, we constructed and characterized the behavior of an LPS mutant with the deepest possible rough phenotype. We generated the defective mutant B. bronchiseptica LP39 on the waaC gene, which codes for a heptosyl transferase involved in the biosynthesis of the core region of the LPS molecule. Although in B. bronchiseptica LP39 the production of the principal virulence determinants adenylate cyclase-hemolysin, filamentous hemagglutinin, and pertactin persisted, the quantity of the two latter factors was diminished, with the levels of pertactin being the most greatly affected. Furthermore, the LPS of B. bronchiseptica LP39 did not react with sera obtained from mice that had been infected with the parental strain, indicating that this defective LPS is immunologically different from the wild-type LPS. In vivo experiments demonstrated that the ability to colonize the respiratory tract is reduced in the mutant, being effectively cleared from lungs within 5 days, whereas the parental strain survived at least for 30 days. In vitro experiments have demonstrated that, although B. bronchiseptica LP39 was impaired for adhesion to human epithelial cells, it is still able to survive within the host cells as efficiently as the parental strain. These results seem to indicate that the deep rough form of B. bronchiseptica LPS cannot represent a dominant phenotype at the first stage of colonization. Since isolates with deep rough LPS phenotype have already been obtained from human B. bronchiseptica chronic infections, the possibility that this phenotype arises as a consequence of selection pressure within the host at a late stage of the infection process is discussed.

Animals↗

PubMed1997

Antigenic polymorphism of the lipopolysaccharides from human and animal isolates of Bordetella bronchiseptica.

Six monoclonal antibodies (mAbs) against lipopolysaccharides (LPS) from Bordetella pertussis (P1P3, 60.5), B. parapertussis (PP2, PP6, PPB) and B. bronchiseptica (BRg1) were used to examine the presence of antigenic determinants of LPS on B. bronchiseptica cells. Forty-eight clinical isolates of this Gram-negative bacterium (4 canine, 3 equine, 6 porcine, 4 rabbit and 31 human) were examined. Significant cross-reactivities with the heterologous anti-pertussis and anti-parapertussis mAbs were observed. The isolates also exhibited marked antigenic polymorphism. The 48 isolates could be classified in six immunogroups. Purified LPS preparations extracted from some isolates were analysed by ELISA, thin-layer chromatography, and tricine-SDS-PAGE. The results show that four main types of antigenic polymorphism of B. bronchiseptica LPSs exist: (a) heterogeneity of the core, (b) presence or absence of O-chains, (c) differences in the hinge region between O-chain and core, and (d) differences in interactions of LPS with other cell-surface constituents. Smooth-type LPS molecules, detectable with mAb PP6, were more frequently observed in animal isolates (94%) than in human isolates (52%). Reverse frequencies were found with mAb 60.5 (48% of human isolates, 18% of animal isolates), which is unable to react with long-chain LPSs. This observation could be due to the general absence of some lectin-like receptor, specific to the O-chain, on human bronchoalveolar tissues.

Animals↗