RESUMO
Psorosis is a widespread and damaging disease of citrus in many parts of the world. The causal agent is a multipartite virus with RNA genome present in very low concentration in infected citrus tissue. Diagnosis is made by biological indexing on indicator citrus seedlings, but it is a slow and costly procedure and therefore it is not used generally. No sensitive wide-spectrum assay for Citrus Psorosis virus (CPsV) has been reported based on RT-PCR. A highly sensitive heminested RT-PCR assay is described for the detection of CPsV. Fragments of 313 bp amplified from RNA 1 of different isolates were cloned and sequenced. Very high homology was found among six isolates from the citrus producing region of Argentina: 96.6-100% in nucleotide sequence. The consensus sequence obtained was used for the design of the primers for heminested PCR assay. It has been tested on different Argentine isolates, employing various methods for RNA extraction from infected tissue. This test is able to detect CPsV in dilutions of 10(10) of the original sample.
Assuntos
Citrus/virologia , Vírus de Plantas/genética , Vírus de Plantas/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Virologia/métodos , Sequência de Bases , Sequência Conservada , Primers do DNA/genética , DNA Viral/genética , Genoma Viral , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa/estatística & dados numéricos , Sensibilidade e Especificidade , Virologia/estatística & dados numéricosRESUMO
We report the case of a 36-year-old woman who suffered tracheal dilatation and rupture despite careful monitoring of intracuff pressure. Surgical manipulation, postoperative mediastinitis, and bacterial staphylococcal tracheitis may be involved in the development of this complication.