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3 results on '"Bottero D"'

1. Pertussis epidemiology in Argentina: trends over 2004–2007.

Author

Hozbor, D., Mooi, F., Flores, D., Weltman, G., Bottero, D., Fossati, S., Lara, C., Gaillard, M.E., Pianciola, L., Zurita, E., Fioriti, A., Archuby, D., Galas, M., Binsztein, N., Regueira, M., Castuma, C., Fingermann, M., and Graieb, A.

Subjects
EPIDEMIOLOGY, MORTALITY, WHOOPING cough vaccines, DEVELOPED countries
Abstract

Summary: Objectives: Pertussis continues causing significant morbidity and mortality worldwide. Although its epidemiology has been studied in many developed countries, the current pertussis situation in South America is scarcely known. This review summarizes the most important recent data concerning pertussis in a country of South America, Argentina. Methods: CDC criteria were used for pertussis diagnosis. Proportion of pertussis cases by age, immunization status, and immunization coverage rate evaluated at the Argentinean National Pertussis Reference Centers was reported. Bordetella pertussis isolates were characterized and compared with vaccine strains. Results: From 2002 to nowadays, a steady increase of pertussis cases was observed. Most of these cases correspond to patients younger than six months old that received less than three doses of vaccine. However, cases in adolescent and adults have also been detected. For this situation, which is not peculiar to Argentina, several explanations have been proposed. Among them, the inability of current vaccines to induce long-lasting immunity is the most widely accepted as a cause of pertussis resurgence. Furthermore, antigenic divergence between local clinical isolates and vaccine strains may have aggravated the effect of waning immunity. Conclusions: Pertussis is an important problem for public health in Argentina. Divergence between vaccine strains and local isolates could contribute to the described pertussis epidemiology. [Copyright &y& Elsevier]

Published
2009
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2. Laboratory Adaptation of Bordetella pertussisIs Associated with the Loss of Type Three Secretion System Functionality

Author

Gaillard, M. E., Bottero, D., Castuma, C. E., Basile, L. A., and Hozbor, D.

Abstract

ABSTRACTAlthough Bordetella pertussiscontains and transcribes loci encoding type III secretion system (TTSS) homologues, expression of TTSS-associated proteins has been reported only for non-laboratory-adapted Irish clinical isolates. Here we confirm such a result for clinical isolates obtained from patients treated in Argentinean hospitals. Moreover, we demonstrate that the expression of TTSS-associated proteins is independent both of the year in which the isolate was obtained and of the types of polymorphic alleles for other virulence factors but is dependent on environmental growth conditions. Interestingly, we observed that TTSS-associated protein expression is lost after successive in vitropassages but becomes operative again when bacteria come into contact with the host. This in vivoactivation of TTSS expression was observed not only for clinical isolates previously adapted to the laboratory after successive in vitropassages but also for vaccine strains that did not express the system in vitro. The reversibility of TTSS expression, demonstrated by its switching off-on when the bacterium comes into contact with the host, appears to be an adaptive response of this pathogen.

Published
2011
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3. Laboratory Adaptation of Bordetella pertussis Is Associated with the Loss of Type Three Secretion System Functionality

Author

Gaillard, M. E., Bottero, D., Castuma, C. E., Basile, L. A., and Hozbor, D.

Abstract

Although Bordetella pertussis contains and transcribes loci encoding type III secretion system (TTSS) homologues, expression of TTSS-associated proteins has been reported only for non-laboratory-adapted Irish clinical isolates. Here we confirm such a result for clinical isolates obtained from patients treated in Argentinean hospitals. Moreover, we demonstrate that the expression of TTSS-associated proteins is independent both of the year in which the isolate was obtained and of the types of polymorphic alleles for other virulence factors but is dependent on environmental growth conditions. Interestingly, we observed that TTSS-associated protein expression is lost after successive in vitro passages but becomes operative again when bacteria come into contact with the host. This in vivo activation of TTSS expression was observed not only for clinical isolates previously adapted to the laboratory after successive in vitro passages but also for vaccine strains that did not express the system in vitro. The reversibility of TTSS expression, demonstrated by its switching off-on when the bacterium comes into contact with the host, appears to be an adaptive response of this pathogen.

Published
2011

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