RESUMO
The pathological consequences of exposure to the vaccine strain Brucella abortus S19 were evaluated in 30 employees from vaccine-manufacturing plants. Active brucellosis was diagnosed in 21 subjects, of whom only five recalled an accidental exposure. Clinical manifestations were mild, and only one patient presented a complication. After antimicrobial therapy, initially symptomatic patients either experienced clinical remission or had mild persistent symptoms. This is the first study reporting infection by B. abortus S19 among workers from vaccine-manufacturing plants, which in many cases was acquired from unnoticed exposures. Measures to improve the safety of B. abortus S19 handling should be implemented.
Assuntos
Vacina contra Brucelose , Brucella abortus/imunologia , Brucelose/diagnóstico , Indústria Farmacêutica/métodos , Pessoal de Laboratório Médico , Exposição Ocupacional , Adulto , Anticorpos Antibacterianos/sangue , Argentina/epidemiologia , Brucella abortus/isolamento & purificação , Brucelose/epidemiologia , Brucelose/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Cows' milk allergy (CMA) is the most common cause of food allergy in infancy. The only proven treatment is the complete elimination of cows' milk proteins (CMPs) from the diet by means of hypoallergenic formulas. Soybean-based formulae are widely used although intolerance to soy has been reported to occur in 15-40% of infants with CMA. OBJECTIVE: The aim of this work was to analyse the in vitro reactivity of the soybean cultivar Raiden, which naturally lacks glycinin A(4)A(5)B(3), to evaluate whether this genotype could be a safe CMP substitute for CMA patients. METHODS: The reactivity of conventional soybean (CS) and Raiden soybean (RS) genotypes and also recombinant glycinin A(4)A(5)B(3) and alphabeta-conglycinin with casein-specific monoclonal antibodies and CMP-specific polyclonal serum was evaluated by immunoblotting and ELISA. A sequential competitive ELISA with the polyclonal antiserum and different soluble inhibitors was performed. In addition, an indirect ELISA with sera of atopic children with CMA was carried out to analyse the IgE-binding capacity of the different soybean components. RESULTS: We have shown that CS contains four components that cross-react with CMP, while RS has only one. The remaining cross-reactive component in RS was identified as alpha-subunit beta-conglycinin. By means of inhibitory ELISA, we demonstrated that CS, RS and the alpha-subunit beta-conglycinin extracts inhibited the binding of CMP-specific antibodies to the CMP-coated solid phase. Finally, we showed that CS, RS and the recombinant proteins were recognized by human CMP-specific IgE antibodies. CONCLUSION: This work shows that although Raiden has fewer cross-reactive components than conventional soybean, it still has a residual cross-reactive component: the alpha-subunit beta-conglycinin. This reactivity might make this genotype unsuitable to treat CMA and also explains adverse reactions to soybean in CMA infants.
Assuntos
Globulinas/isolamento & purificação , Glycine max/química , Hipersensibilidade a Leite/imunologia , Leite/imunologia , Proteínas de Armazenamento de Sementes/isolamento & purificação , Proteínas de Soja/isolamento & purificação , Animais , Antígenos de Plantas , Caseínas/imunologia , Bovinos , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Genótipo , Globulinas/imunologia , Humanos , Immunoblotting , Imunoglobulina E/imunologia , Proteínas do Leite/imunologia , Subunidades Proteicas/genética , Subunidades Proteicas/imunologia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas de Armazenamento de Sementes/imunologia , Proteínas de Soja/imunologia , Glycine max/genética , Glycine max/imunologiaRESUMO
Fabry disease is an X-linked lysosomal disorder caused by the deficiency of the lysosomal enzyme alpha-galactosidase A (alpha-Gal A). In males, the laboratory diagnosis is based on the demonstration of decreased levels of alpha-Gal A activity, while in females, the disease is diagnosed by the identification of a mutation in alpha-Gal A gene. Fabry disease in Argentina is underdiagnosed. To date, no comprehensive screening study of Fabry disease in our country has been reported. The present study aimed at developing a targeted screening for the detection of Fabry patients from Argentina based on the set of typical signs and symptoms. We received 121 blood samples from probable Fabry patients for enzymatic and genetic assay. We diagnosed six Fabry patients from six unrelated families, representing a yield of detection of 4.96%. The mutations detected in five of the families analysed were missense mutations: p.Leu243Trp, p.Asp155His, p.Leu415Pro, p.Cys94Tyr and p.Leu191Pro. After the detection of a Fabry patient, his/her relatives were also screened. In the course of these family studies, other 64 Fabry patients, 29 males and 35 females, were detected. To our knowledge, this is the first comprehensive screening of Fabry disease in Argentina. We detected 70 patients in a period of 2.5 years. The development of targeted protocols and the constitution of interdisciplinary groups for the identification of patients with Fabry disease are recommended to obtain a higher yield in the process.
Assuntos
Doença de Fabry/diagnóstico , Triagem Multifásica/métodos , alfa-Galactosidase/genética , alfa-Galactosidase/metabolismo , Adulto , Argentina , Estudos de Coortes , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , FenótipoRESUMO
P36 is a member of a family of secreted proteins distributed throughout the genus Mycobacterium. The central domain of these proteins contains several amino acid PGLTS repeats, which differ considerably between species. P36, also called exported repetitive protein (Erp) in M. tuberculosis, has been shown to be associated with virulence since the disruption of its gene impaired multiplication of both virulent M. tuberculosis and M. bovis BCG in cultured macrophages and immunocompetent mice. In order to demonstrate that P36 is a putative virulence factor of wild-type Mycobacterium bovis we generated a P36 mutant by gene disruption and we evaluated its replication in spleen and lungs of infected mice. In this study, the mutant strain displays low levels of multiplication in mice, indicating that the P36 gene is important for in vivo growth of M. bovis.
Assuntos
Bacillus/genética , Proteínas de Bactérias/genética , Proteínas de Membrana/genética , Mutação/genética , Mycobacterium bovis/genética , Animais , Western Blotting , Eletroforese em Gel de Poliacrilamida , Feminino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
The prevalence of specific IgE to natural rubber latex proteins in the general population remains uncertain. The purpose of this study was to determine the prevalence of sera containing specific IgE antibodies to latex proteins using immunoenzymatic methods. A population of 500 unselected adult voluntary blood donors was the source of the sera used in this study. Two different immunoenzymatic methods (EAST and CARLA) were used to analyze the presence of specific IgE antibodies. Confirmation assay was carried out by inhibition ELISA and immunoblotting. Sera from healthy nonatopic individuals were also used as control. Two hundred and twenty five sera showed higher than normal total IgE levels. Of those, three presented latex specific IgE antibodies, which could be inhibited in a dose-response manner with the natural rubber latex and glove extracts. Several latex allergens were recognized by the IgE antibodies from these positive sera. This low seroprevalence (0.66%) indicates that latex hypersensitivity is not an important problem in the general population. We believe that prevention of latex exposure is only necessary in high risk groups of patients.
Assuntos
Doadores de Sangue , Imunoglobulina E/sangue , Látex/imunologia , Argentina/epidemiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Immunoblotting , Técnicas Imunoenzimáticas , Hipersensibilidade ao Látex/epidemiologia , Prevalência , Borracha , Estudos SoroepidemiológicosRESUMO
Protein assemblies with a high degree of repetitiveness and organization are known to induce strong immune responses. For that reason they have been postulated for the design of subunit vaccines by means of protein engineering. The enzyme lumazine synthase from Brucella spp. (BLS) is highly immunogenic, presumably owing to its homodecameric arrangement and remarkable thermodynamic stability. Structural analysis has shown that it is possible to insert foreign peptides at the ten amino terminus of BLS without disrupting its general folding. These peptides would be displayed to the immune system in a highly symmetric three-dimensional array. In the present work, BLS has been used as a protein carrier of foreign peptides. We have established a modular system to produce chimeric proteins decorated with ten copies of a desired peptide as long as 27 residues and have shown that their folding and stability is similar to that of the wild-type protein. The knowledge about the mechanisms of dissociation and unfolding of BLS allowed the engineering of polyvalent chimeras displaying different predefined peptides on the same molecular scaffold. Moreover, the reassembly of mixtures of chimeras at different steps of the unfolding process was used to control the stoichiometry and spatial arrangement for the simultaneous display of different peptides on BLS. This strategy would be useful for vaccine development and other biomedical applications.