RESUMEN
O objetivo deste estudo foi detectar rotavírus em fezes de bezerros com diarreia em Uberaba, MG, e caracterizar os genes VP7 e VP4 por meio da genotipagem e da análise filogenética. Setenta e quatro amostras foram coletadas entre novembro de 2008 e setembro de 2009. A detecção do vírus foi feita por teste de aglutinação e as amostras positivas foram submetidas à transcrição reversa, seguida de reação em cadeia da polimerase (RT-PCR), tipagem por PCR e sequenciamento. A taxa de detecção de rotavírus foi de 6,8% e todas as amostras apresentaram o genótipo G6P[5]. A análise filogenética mostrou que as amostras do genótipo G6 pertencem à linhagem IV e que, para ambos os genes (VP7 e VP4), as amostras deste estudo compõem um sub-cluster à parte daquele das cepas referências e das amostras campo mais similares. O alinhamento das sequências de aminoácidos deduzidas mostrou substituições em regiões antigênicas quando comparadas com as sequências das cepas bovinas UK e NCDV, presentes nas vacinas disponíveis no Brasil. Uma nova sublinhagem genética de G6P[5] foi evidenciada neste estudo. Substituições de aminoácidos nas regiões antigênicas dos rotavírus e a circulação de novas variantes podem representar desafios para as vacinas utilizadas atualmente. O presente estudo contribui para a compreensão da epidemiologia dos rotavírus bovinos no Brasil.(AU)
Asunto(s)
Animales , Bovinos , Técnicas de Genotipaje/veterinaria , Rotavirus , Vacunas contra Rotavirus/genética , Pruebas de Fijación de Látex/veterinariaRESUMEN
Polymorphisms present in the TNF promoter region has shown to influence the gene transcription. Leprosy displays different clinical manifestations according to the immune responses of the individual infected with Mycobacterium leprae. In this study, we evaluated the single nucleotide polymorphisms (SNPs) -238 G/A (rs361525), -308 G/A (rs1800629), -857 C/T (rs1799724), -863 A/C (rs1800630) and -1031 T/C (rs1799964) in the promoter region of the TNF to see whether these SNPs influence host-susceptibility to leprosy and the different clinical manifestation. Nucleotide sequencing was performed with DNA samples from 108 leprosy patients and 253 control subjects. An association between -1031 C/C genotype and protection from leprosy was observed when leprosy patients were compared to controls (OR 0.11; 95% CI=0.01-0.82; p=0.012). The -857 C/T genotype may be associated with susceptibility to leprosy (OR=1.81; 95% CI=1.09-3.00; p=0.028). Similar genotype and allele frequencies for the SNPs -308 G/A and -238 G/A were observed between leprosy patients and control subjects. Altogether, TNF polymorphisms in the promoter region may be predictive of leprosy outcome.
Asunto(s)
Lepra/inmunología , Mycobacterium leprae/inmunología , Factor de Necrosis Tumoral alfa/genética , Biomarcadores/metabolismo , Brasil , Análisis Mutacional de ADN , Progresión de la Enfermedad , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Lepra/diagnóstico , Lepra/genética , Polimorfismo de Nucleótido Simple , Valor Predictivo de las Pruebas , Regiones Promotoras Genéticas/genéticaRESUMEN
Leprosy displays a wide clinical spectrum that is dependent of the type of immune response. We investigate here whether polymorphisms in the promoter region of the IL12RB2 gene are associated with susceptibility or resistance to clinical forms of leprosy. Nucleotide sequencing of the promoter region of IL12RB2 encompassing SNPs -1035 A/G, -1033 T/C, -1023 A/G, -650 del/G and -464 A/G was performed on DNA samples from 105 leprosy patients and 108 healthy controls. However, none of the SNPs were associated with susceptibility to the disease or any of its clinical forms. Similarly, haplotype analysis did not show any association. The haplotype -1035A/-1033T/-650G/-464A was prevalent, and homozygosity for this haplotype was associated to a lower distribution of CD4(+) T cells (p=0.041). Our data suggest that polymorphisms present in the promoter region of IL12RB2 may not be associated with susceptibility to leprosy or its clinical forms.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Lepra/genética , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Receptores de Interleucina-12/genética , Adolescente , Adulto , Anciano , Brasil , Recuento de Linfocito CD4 , Linfocitos T CD4-Positivos/patología , Estudios de Casos y Controles , Susceptibilidad a Enfermedades , Femenino , Frecuencia de los Genes , Haplotipos , Homocigoto , Humanos , Lepra/inmunología , Lepra/patología , Masculino , Persona de Mediana EdadRESUMEN
Previous studies identified the variant IFNG +874A/T (rs2430561) in the first intron of the gene in association with mycobacterial infection, especially tuberculosis and leprosy. The aim of this investigation was to analyze the protective role of the T allele in relation to leprosy using a meta-analysis evaluation. Thus, 1573 patients and 1914 controls were included and analyzed in fixed effects model. The T allele is associated with a protective effect for leprosy under the dominant model (pooled OR=0.83, 95% CI=0.72-0.96, p=0.011) suggesting that carriers of the IFNG +874T allele may be protected from developing leprosy. The T allele has been suggested to correlate with high interferon-γ levels. A phenotype with high IFN-γ producing and an increased inflammatory profile may account for these findings. This meta-analysis suggests that IFNG +874T allele is associated with leprosy resistance.
Asunto(s)
Resistencia a la Enfermedad/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Interferón gamma/genética , Lepra/genética , Lepra/inmunología , Polimorfismo de Nucleótido Simple/genética , Alelos , Heterogeneidad Genética , Humanos , Sesgo de PublicaciónRESUMEN
Polymorphisms present in the first intron of IFN-γ may have an important role in the regulation of the immune response, which could have functional consequences for gene transcription. Leprosy patients are characterized by different immune responses in different clinical forms. We investigated a possible association of the +874 polymorphism and CA repeats present in the first intron of IFN-γ with susceptibility to leprosy and with the manifestation of the different clinical forms. Nucleotide sequencing was performed with samples from 108 leprosy patients and 113 controls subjects, as well as immunophenotyping of CD(4)(+), CD(8)(+) and CD(69)(+) T cells by flow cytometry. The data showed that there were no significant differences between patients and control subjects, as well as according classification of Ridley-Jopling. However, the A/A genotype was significantly increased in paucibacillary patients (p=0.028) and the microsatellite encoding 16 CA repeats were significantly associated with paucibacillary compared to multibacillary patients (p=0.019). Individuals homozygous for the +874 A allele, the mean level of CD(4)(+) and CD(69)(+) T cells was higher. Our data suggest that polymorphisms present in the first intron of IFN-γ are not associated with susceptibility to leprosy, nevertheless, the +874 polymorphism and the CA repeats number encoded in IFN-γ gene may be related to a higher cellular immune response in patients and are consistently more frequently detected in PB patients.
Asunto(s)
Predisposición Genética a la Enfermedad , Interferón gamma/genética , Lepra/genética , Lepra/prevención & control , Repeticiones de Microsatélite/genética , Polimorfismo de Nucleótido Simple/genética , Adolescente , Adulto , Anciano , Alelos , Biomarcadores/metabolismo , Brasil , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes/genética , Humanos , Subgrupos Linfocitarios/inmunología , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
In order to develop good polices regarding public health measures and vaccine use to prevent rotavirus induced gastroenteritis, the epidemiology of the illness in various regions of Brazil is necessary. Accordingly, this study was to detect the frequency and types of rotavirus in one city in a tropical part of Brazil. This is an epidemiological survey of pediatric gastroenteritis caused by rotavirus conducted in Juiz de Fora, Minas Gerais State, Brazil. We analyzed 656 in-patient (190) and out-patient (466) stool samples from children ages 0 to 5 years during 1998. Rotavirus detection was performed using polyacrylamide gel electrophoresis (PAGE). Rotavirus was isolated from 62/190 stool samples (32.6%) from hospitalized children and 16/466 (3.4%) from out-patients. The overall rotavirus frequency in this population was 11.9%. The highest rotavirus detection was found in hospitalized children ages 6 to 24 months. Rotaviruses were detected from March to September, with a peak incidence in June (33.3%), the coldest and driest month in the region. Electrophoretic analysis identified 10 different profiles, all long and compatible with group A rotavirus, termed L(A) through LJ. The L(B) and L(D) profiles circulated throughout most of the study period. However, in June, when the highest detection rate occurred, the vast majority (92.5%) of the positive samples displayed the L(B) profile, thus suggesting an outbreak caused by this rotavirus profile. Rotavirus induced gastroenteritis is common in one tropical region of Brazil, it is an important cause of diarrhea in hospitalized children ages 6 to 24 months, it is most common during dry, cold months of the year, and it may occur in electrophoretype restricted epidemics. Such analyses throughout Brazil will assist in developing sound guidelines regarding its prevention.