RESUMO
AIM: To characterize Bordetella pertussis vaccine strains in comparison with current circulating bacteria. METHODS AND RESULTS: Genomic and proteomic analyses of Bp137 were performed in comparison with other vaccine strains used in Latin America (Bp509 and Bp10536) and with the clinical Argentinean isolate Bp106. Tohama I strain was used as reference strain. Pulse-field gel electrophoresis (PFGE) and pertussis toxin promoter (ptxP) sequence analysis revealed that Bp137 groups with Bp509 in PFGE group III and contains ptxP2 sequence. Tohama I (group II) and Bp10536 (group I) contain ptxP1 sequence, while Bp106 belongs to a different PFGE cluster and contains ptxP3. Surface protein profiles diverged in at least 24 peptide subunits among the studied strains. From these 24 differential proteins, Bp10536 shared the expression of ten proteins with Tohama I and Bp509, but only three with Bp137. In contrast, seven proteins were detected exclusively in Bp137 and Bp106. CONCLUSIONS: Bp137 showed more features in common with the clinical isolate Bp106 than the other vaccine strains here included. SIGNIFICANCE AND IMPACT OF THE STUDY: The results presented show that the old strains included in vaccines are not all equal among them. These findings together with the data of circulating bacteria should be taken into account to select the best vaccine to be included in a national immunization programme.
Assuntos
Bordetella pertussis/genética , Bordetella pertussis/imunologia , Vacina contra Coqueluche/genética , Vacina contra Coqueluche/imunologia , Bordetella pertussis/classificação , Bordetella pertussis/isolamento & purificação , Genótipo , Humanos , Programas de Imunização , América Latina , Fenótipo , ProteômicaRESUMO
INTRODUCTION: Systolic blood pressure (SBP) is still measured in rats by the tail-cuff method, allowing readings when pulse/flow disappears during cuff inflation and reappears during deflation, separated by a compression interval. Although cuff deflation is habitually used to estimate SBP, we found cuff deflation-cuff inflation pressure to be usually negative, indicating that cuff deflation pressure < cuff inflation pressure. METHODS: SBP was measured in 226 male Wistar and SHR utilizing compression intervals of different durations, and also pharmacological interventions intended to modulate the cuff deflation-cuff inflation cycle. Direct, simultaneous intravascular measurements were also performed in some animals. RESULTS AND DISCUSSION: With compression interval congruent with 15 s, cuff deflation-cuff inflation was--6 +/- 0.6 mmHg in 73 Wistar and--6 +/- 1.4 mmHg in 51 SHR. Lengthening compression interval up to 4 min increased cuff deflation-cuff inflation pressure significantly to--27 +/- 3 mmHg in Wistar and to - 31 +/- 5 mmHg in SHR, suggesting accumulation of a vasodilating mediator. This increase of cuff deflation-cuff inflation pressure was prevented by papaverine (totally in Wistar, partially in SHR), indicating its dependence on vasodilatory capacity. Adrenergic blockade decreased cuff deflation-cuff inflation pressure to--13 +/- 5 mmHg (P < 0.05) in SHR, but had no effect in Wistar rats. Injection of L-NAME decreased cuff deflation-cuff inflation pressure to--5 +/- 2 mmHg (P < 0.05) in Wistar rats but was ineffective in SHR. Simultaneous measurements by tail-cuff method and carotid cannulation revealed that the cuff inflation most accurately estimated the intravascular SBP. CONCLUSIONS: 1) Cuff inflation measurements should be considered representative of SBP, as cuff deflation can underestimate SBP depending on compression interval duration, 2) nitric oxide accumulation due to flow deprivation is the main cause of SBP underestimation by cuff deflation in Wistar, and 3) in SHR, nitric oxide effects were minimal, and sympathetic activation plus physical factors seemed to predominate in the determining the outcome of measurements.
Assuntos
Pressão Sanguínea/fisiologia , Hipertensão/fisiopatologia , Cauda/irrigação sanguínea , Antagonistas Adrenérgicos alfa/administração & dosagem , Antagonistas Adrenérgicos alfa/farmacologia , Fatores Etários , Animais , Determinação da Pressão Arterial/instrumentação , Determinação da Pressão Arterial/métodos , Monitores de Pressão Arterial , Injeções Intraperitoneais , Masculino , NG-Nitroarginina Metil Éster/administração & dosagem , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Papaverina/administração & dosagem , Papaverina/farmacologia , Fenoxibenzamina/administração & dosagem , Fenoxibenzamina/farmacologia , Propranolol/administração & dosagem , Propranolol/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Reprodutibilidade dos Testes , Especificidade da Espécie , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/fisiologia , Sistema Vasomotor/efeitos dos fármacos , Sistema Vasomotor/fisiologiaRESUMO
Background: In 1999 an International Commission of Experts evaluated the sanitary interventions that started in 1980 to eliminate Triatoma infestans, the biological vector of Chagas disease, to certify if the conditions needed to interrupt the transmission, were achieved. Aim: To report the data used by the International certification commission to certify the interruption of vectorial transmission of Chagas disease in Chile. Material and methods : A comparative evaluation of the prevalence of Trypanosoma cruzi antibodies in children surveyed between 1994 and 1995 and between 1995 and 1999. Results : In the first period, 5.948 children were surveyed and in the second, 5.069 children were studied. Twenty children (0.4 percent) were positive for Trypanosoma cruzi antibodies in the second survey. These figures were significantly lower than the 1.1 percent prevalence detected between 1994 and 1995. In only three of the 20 cases, the transmission through vectors was confirmed, which represents a 99.4 percent reduction of this way of transmission. Conclusions: Based on these findings, the Commission certified that Chile is the second country in Latin America to interrupt the vector transmission of Chagas disease. The successful public health program for Chagas disease will have a positive impact improving the quality of life of rural populations, that are most exposed to the disease