RESUMEN
An outbreak of coronavirus disease began in a large penitentiary complex in Brazil on April 1, 2020. By June 12, there were 1,057 confirmed cases among inmates and staff. Nine patients were hospitalized, and 3 died. Mean serial interval was ≈2.5 days; reproduction number range was 1.0-2.3.
Asunto(s)
COVID-19/epidemiología , Brotes de Enfermedades/estadística & datos numéricos , Prisiones/estadística & datos numéricos , Adolescente , Adulto , Anciano , Número Básico de Reproducción , Brasil , COVID-19/mortalidad , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
The C-terminal region of the Leptospiral immunoglobulin-like A protein (LigA) contains six carboxy-terminal Ig-like repeat domains (LigANI). Subunit vaccine preparations based on recombinant LigANI produced in Escherichia coli, are promising vaccine candidates, albeit with variable efficacy. In the present study, LigANI was expressed in the methylotrophic yeast Pichia pastoris using a 12 L bioreactor to produce mannosylated LigANI (mLigANI) for use in a vaccine preparation against leptospirosis. Hamsters immunized with a mLigANI vaccine preparation produced a significant IgG antibody response (P < 0.001) and were protected (83.3 %; P < 0.001) against lethal challenge with 36× LD50 of a virulent strain of L. interrogans serovar Copenhageni. A vaccine preparation based on demannosylated mLigANI (nmLigANI) elicited an immune response in hamsters, but did not afford protection. The production of mLigANI in bioreactor by P. pastoris yielded ~50 mg L(-1) of recombinant protein. P. pastoris is a potential platform for the production of leptospiral antigens on an industrial scale. The results demonstrate that LigANI secreted by P. pastoris on mannosylated form (mLigANI) protect hamsters as subunit vaccine of L. interrogans lethal infection.
Asunto(s)
Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Reactores Biológicos , Leptospira/química , Leptospirosis/prevención & control , Proteínas Recombinantes/inmunología , Animales , Antígenos Bacterianos/genética , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cricetinae , Femenino , Leptospira/genética , Leptospirosis/inmunología , Pichia/genética , Pichia/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Análisis de SupervivenciaRESUMEN
Bovine herpesviruses 1 and 5 (BoHV-1 and BoHV-5) are economically important pathogens, associated with a variety of clinical syndromes, including respiratory and genital disease, reproductive failure and meningoencephalitis. The standard serological assay to diagnose BoHV-1 and BoHV-5 infections is the virus neutralization test (VNT), a time consuming procedure that requires manipulation of infectious virus. In the present study a highly sensitive and specific single dilution indirect ELISA was developed using recombinant glycoprotein D from BoHV-5 as antigen (rgD5ELISA). Bovine serum samples (n = 450) were screened by VNT against BoHV-5a and by rgD5ELISA. Compared with the VNT, the rgD5ELISA demonstrated accuracy of 99.8%, with 100% sensitivity, 96.7% specificity and coefficient of agreement between the tests of 0.954. The rgD5ELISA described here shows excellent agreement with the VNT and is shown to be a simple, convenient, specific and highly sensitive virus-free assay for detection of serum antibodies to BoHV-5.
Asunto(s)
Enfermedades de los Bovinos/diagnóstico , Encefalitis Viral/diagnóstico , Ensayo de Inmunoadsorción Enzimática/métodos , Infecciones por Herpesviridae/diagnóstico , Meningoencefalitis/diagnóstico , Proteínas del Envoltorio Viral/aislamiento & purificación , Animales , Anticuerpos Antivirales/sangre , Área Bajo la Curva , Bovinos , Enfermedades de los Bovinos/virología , Perros , Encefalitis Viral/inmunología , Geografía , Infecciones por Herpesviridae/inmunología , Herpesvirus Bovino 5 , Células de Riñón Canino Madin Darby , Meningoencefalitis/inmunología , Pruebas de Neutralización , Pichia , Curva ROC , Proteínas Recombinantes/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Proteínas del Envoltorio Viral/inmunologíaRESUMEN
The aim of this work was to evaluate the utilization of analysis of the distribution of relaxation time (DRT) using a dynamic light back-scattering technique as alternative method for the determination of the concentration regimes in aqueous solutions of biopolymers (xanthan, clairana and tara gums) by an analysis of the overlap (c*) and aggregation (c**) concentrations. The diffusion coefficients were obtained over a range of concentrations for each biopolymer using two methods. The first method analysed the behaviour of the diffusion coefficient as a function of the concentration of the gum solution. This method is based on the analysis of the diffusion coefficient versus the concentration curve. Using the slope of the curves, it was possible to determine the c* and c** for xanthan and tara gum. However, it was not possible to determine the concentration regimes for clairana using this method. The second method was based on an analysis of the DRTs, which showed different numbers of relaxation modes. It was observed that the concentrations at which the number of modes changed corresponded to the c* and c**. Thus, the DRT technique provided an alternative method for the determination of the critical concentrations of biopolymers.