Letter to the Editor : Bordetella pertussis Polymorphism and Pertussis Vaccines

First, I want to clarify for Dr. Guiso that in no part of our paper did we state that “the vaccines are not protecting against new circulating isolates.” Therefore, I recommend a more careful reading of our work in order to determine the true subject under discussion. My colleagues and I will not argue about what is not stated in the article. On the other hand, it is important to point out that all protection results presented in our paper were obtained using mice, and thus, care in making extrapolations to humans must be taken.Facultad de Ciencias Exacta

Letter to the Editor : Bordetella pertussis Polymorphism and Pertussis Vaccines

First, I want to clarify for Dr. Guiso that in no part of our paper did we state that “the vaccines are not protecting against new circulating isolates.” Therefore, I recommend a more careful reading of our work in order to determine the true subject under discussion. My colleagues and I will not argue about what is not stated in the article. On the other hand, it is important to point out that all protection results presented in our paper were obtained using mice, and thus, care in making extrapolations to humans must be taken.Facultad de Ciencias Exacta

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.Instituto de Biotecnologia y Biologia MolecularFacultad de Ciencias Exacta

Pertussis vaccination in mixed markets: Recommendations from the Global Pertussis Initiative

The Global Pertussis Initiative is an expert scientific forum that publishes consensus recommendations concerning pertussis for many regions of the world. Here, we give recommendations for the primary vaccination of infants in those countries where whole-cell pertussis (wP)- and acellular pertussis (aP)-containing combination vaccines are used in parallel. A selective literature review was performed concerning the influence on safety, immunogenicity, and effectiveness of mixing wP- and aP-containing vaccines for primary immunization of infants. In addition, local data were collected from various countries and the results discussed in a face-to-face meeting. Very few data addressing issues of mixing combination vaccines were identified, and no data were available concerning the effectiveness or duration of protection. It was also found that pharmacovigilance data are scarce or lacking in those countries where they would be needed the most. We then identified frequent problems occurring in low- and middle-income countries (LMICs) where both vaccine types are used. Relying on local knowledge, we give practical recommendations for a variety of situations in different settings. Specific needs for additional data addressing these issues were also identified. International bodies, such as the World Health Organization (WHO), as well as vaccine producers should try to find ways to highlight the problems of mixing wP- and aP-containing combination vaccines with robust data. Countries are urged to improve on their pharmacovigilance for vaccines. For practicing physicians, our recommendations offer guidance when wP- and aP-containing vaccines are used in parallel during primary immunization.Fil: Chitkara, Amar J.. Max Super Speciality Hospital; IndiaFil: Pujadas Ferrer, Mónica. Universidad de la República; UruguayFil: Forsyth, Kevin. Flinders University.; AustraliaFil: Guiso, Nicole. Institut Pasteur de Paris.; FranciaFil: Heininger, Ulrich. Universidad de Basilea; SuizaFil: Hozbor, Daniela Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Muloiwa, Rudzani. University of Cape Town; SudáfricaFil: Tan, Tina Q.. Northwestern University; Estados UnidosFil: Thisyakorn, Usa. Chulalongkorn University; TailandiaFil: Wirsing von König, C.H.. No especifíca

Processamento auditivo em crianças e adolescentes em situação de risco e vulnerabilidade

CONTEXT AND OBJECTIVE: Children and adolescents who live in situations of social vulnerability present a series of health problems. Nonetheless, affirmations that sensory and cognitive abnormalities are present are a matter of controversy. The aim of this study was to investigate aspects to auditory processing, through applying the brainstem auditory evoked potential (BAEP) and behavioral auditory processing tests to children living on the streets, and comparison with a control group. DESIGN AND SETTING: Cross-sectional study in the Laboratory of Auditory Processing, School of Medicine, Universidade de São Paulo. METHODS: The auditory processing tests were applied to a group of 27 individuals, subdivided into 11 children (7 to 10 years old) and 16 adolescents (11 to 16 years old), of both sexes, in situations of social vulnerability, compared with an age-matched control group of 10 children and 11 adolescents without complaints. The BAEP test was also applied to investigate the integrity of the auditory pathway. RESULTS: For both children and adolescents, there were significant differences between the study and control groups in most of the tests applied, with significantly worse performance in the study group, except in the pediatric speech intelligibility test. Only one child had an abnormal result in the BAEP test. CONCLUSIONS: The results showed that the study group (children and adolescents) presented poor performance in the behavioral auditory processing tests, despite their unaltered auditory brainstem pathways, as shown by their normal results in the BAEP test

Release of outer membrane vesicles from Bordetella pertussis

The aim of the study reported here was to investigate the production of Bordetella pertussis outer membrane vesicles (OMVs). Numerous vesicles released from cells grown in Stainer-Scholte liquid medium were observed. The formation of similar vesicle-like structures could also be artificially induced by sonication of concentrated bacterial suspensions. Immunoblot analysis showed that OMVs contain adenylate cyclase-hemolysin (AC-Hly), among other polypeptides, as well as the lipopolysaccharide (LPS). Experiments carried out employing purified AC-Hly and OMVs isolated from B. pertussis AC-Hly− showed that AC-Hly is an integral component of the vesicles. OMVs reported here contain several protective immunogens and might be considered a possible basic material for the development of acellular pertussis vaccines.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesInstituto de Biotecnología y Biología Molecula

New Pertussis Vaccination Strategies beyond Infancy: Recommendations by the Global Pertussis Initiative

Background. The Global Pertussis Initiative, an expert scientific forum, was established to address the ongoing problems associated with pertussis disease worldwide. Methods. The group analyzed pertussis disease trends, developed recommendations to improve disease control through expanded vaccination strategies, and proposed solutions to barriers to implementation and support of research activities. Results. Bordetella pertussis infection is endemic and continues to be a serious problem among unvaccinated or incompletely vaccinated infants. In addition, the reported incidence of pertussis disease is increasing in adolescents and adults, who not only experience a considerable health burden themselves but also infect vulnerable infants. Conclusions. Current vaccination strategies need to be reinforced. Expanded vaccination should include adding booster doses to existing childhood schedules (preschool or adolescent) and booster doses for those specific adult subgroups that have the highest risk of transmitting B. pertussis infection to infants (i.e., new parents, other contacts of newborns, and health care workers). More epidemiological studies and studies of disease transmission and the cost-effectiveness of vaccination would be valuable, and surveillance, diagnostic improvements, and educational campaigns are needed for implementation. However, as a prelude to universal adult vaccination, immediate universal adolescent vaccination should be instituted in countries in which it is economically feasibl

Bordetella pertussis, Finland and France

We used pulsed-field gel electrophoresis analysis and genotyping to compare clinical isolates of Bordetella pertussis recovered since the early 1990s in Finland and France, 2 countries with similar histories of long-term mass vaccination with whole-cell pertussis vaccines. Isolates from both countries were similar genetically but varied temporally