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1.
J Virol Methods ; 327: 114948, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38718900

RESUMO

Rabies, a fatal zoonotic viral disease affecting mammals, including humans, remains a significant global health concern, particularly in low-income countries. The disease, primarily transmitted through infected animal saliva, prompts urgent diagnosis for timely post-exposure prophylaxis (PEP). The gold standard diagnostic test, direct fluorescent antibody test (dFAT), while sensitive, suffers from limitations such as subjective interpretation and high costs. As a confirmatory technique, the LN34 Pan-Lyssavirus RT-qPCR assay has emerged as a promising tool for universal Lyssavirus detection. This study evaluated its performance using 130 rabies virus isolates representing eleven Brazilian variants and 303 clinical samples from surveillance operations. The LN34 assay demonstrated 100% sensitivity and 98% specificity compared to dFAT. Additionally, it detected all samples, including those missed by dFAT, indicating superior sensitivity. The assay's specificity was confirmed through Sanger nucleotide sequencing, with only a minimal false-positive rate. Comparative analysis revealed higher accuracy and concordance with dFAT than traditional rabies tissue culture infection tests (RTCIT). False-negative RTCIT results were attributed to low viral load or suboptimal sampling. These findings underscore the LN34 assay's utility as a confirmatory technique, enhancing rabies surveillance and control in Brazil. Its widespread adoption could significantly improve diagnostic sensitivity, crucial for effective PEP and public health interventions.


Assuntos
Vírus da Raiva , Raiva , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Raiva/diagnóstico , Raiva/veterinária , Raiva/virologia , Brasil , Vírus da Raiva/genética , Vírus da Raiva/isolamento & purificação , Vírus da Raiva/classificação , Humanos , Animais , Reação em Cadeia da Polimerase em Tempo Real/métodos , Lyssavirus/genética , Lyssavirus/isolamento & purificação , Lyssavirus/classificação , RNA Viral/genética , Carga Viral
2.
Avian Dis ; 55(4): 697-700, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22312995

RESUMO

Rotaviruses are the main agents responsible for diarrhea in different animal species and for infantile gastroenteritis. These viruses have been isolated from various avian species and have often been associated with poult enteritis and mortality syndrome. Nevertheless, the knowledge of rotavirus infection in turkeys is scarce. Six group A rotavirus strains obtained from pooled enteric contents of diarrheic turkeys were isolated in MA-104 cell culture and typed as G(6)P(1), a typical bovine rotavirus genotype. Additionally, the electropherotypes showed a migration pattern identical to the Nebraska calf diarrhea virus, and the complete NSP4 gene phylogeny showed that all six strains segregated in the genotype E2. Taken together, these results point toward a cattle-to-turkey rotavirus transmission. As a conclusion, bovine-origin rotavirus can be found in turkeys, and this transmission route must now be considered for the improvement of the health status in turkey farms.


Assuntos
Enterite/veterinária , Doenças das Aves Domésticas/virologia , Rotavirus/classificação , Perus , Animais , Antígenos Virais/genética , Proteínas do Capsídeo/genética , DNA Viral , Enterite/virologia , Filogeografia , Rotavirus/isolamento & purificação
3.
J Virol Methods ; 283: 113918, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32554044

RESUMO

The direct-fluorescent antibody test (dFAT) is considered the "gold standard" assay to diagnose rabies. However, it is crucial to develop molecular techniques, such as RT-PCR and RT-qPCR, since many laboratories lack the needed supplies for performing complementary methods (viral isolation, for example). For this purpose, diagnostic techniques must be specific and sensitive to guarantee accuracy. This present investigation aimed to detect rabies virus (RABV) in 126 clinically suspected cattle in Brazil using different diagnostic tests [dFAT, mouse inoculation test (MIT), immunohistochemistry (IHC), RT-PCR and RT-qPCR] and to compare those results obtained under routine laboratory conditions. The results of the present investigation demonstrate that the molecular techniques are more sensitive and may detect low viral load, even though the non-homogeneous viral distribution caused a false-negative result in dFAT. We also observed a usual alteration in antigens distribution among regions of the central nervous system (CNS). By both dFAT and IHC assays, the most reliable CNS structures were thalamus and midbrain. Although this investigation demonstrated diagnostic sensitivity and specificity close to 100 % in all laboratory techniques employed, a dFAT auxiliary test is required for bovine specimens, such as molecular techniques, when there are poor sampling conditions (low viral load combined with unavailability of brainstem structures).


Assuntos
Doenças dos Bovinos/diagnóstico , Técnicas de Laboratório Clínico/métodos , Testes Imunológicos/métodos , Raiva/diagnóstico , Raiva/veterinária , Animais , Brasil , Bovinos , Doenças dos Bovinos/virologia , Modelos Animais de Doenças , Técnica Direta de Fluorescência para Anticorpo/métodos , Imuno-Histoquímica/métodos , Camundongos , Raiva/imunologia , Raiva/virologia , Vírus da Raiva/imunologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e Especificidade , Carga Viral
4.
Biomed Res Int ; 2016: 8560691, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27243037

RESUMO

Feline infectious peritonitis virus (FIPV) is highly virulent and responsible for the highly fatal disease feline infectious peritonitis (FIP), whereas feline enteric coronavirus (FECV) is widespread among the feline population and typically causes asymptomatic infections. Some candidates for genetic markers capable of differentiating these two pathotypes of a unique virus (feline coronavirus) have been proposed by several studies. In the present survey, in order to search for markers that can differentiate FECV and FIPV, several clones of the 3a-c, E, and M genes were sequenced from samples obtained from cats with or without FIP. All genes showed genetic diversity and suggested the presence of FCoV mutant spectrum capable of producing a virulent pathotype in an individual-specific way. In addition, all the feline coronavirus FIPV strains demonstrated a truncated 3c protein, and the 3c gene was the only observed pathotypic marker for FCoVs, showing that 3c gene is a candidate marker for the distinction between the two pathotypes when the mutant spectrum is taken into account.


Assuntos
Coronavirus Felino/genética , Coronavirus Felino/patogenicidade , Genes Virais/genética , Marcadores Genéticos/genética , Proteínas Virais/genética , Virulência/genética , Animais , Gatos , Peritonite Infecciosa Felina/virologia , Variação Genética/genética , Mutação/genética , Filogenia
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