Assuntos
Neoplasias Cardíacas , Linfoma Difuso de Grandes Células B , Neoplasias Abdominais/diagnóstico por imagem , Neoplasias Abdominais/patologia , Neoplasias Abdominais/terapia , Adulto , Dor no Peito/etiologia , Dispneia/etiologia , Feminino , Neoplasias Cardíacas/complicações , Neoplasias Cardíacas/diagnóstico por imagem , Neoplasias Cardíacas/patologia , Neoplasias Cardíacas/terapia , Humanos , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Neoplasias Renais/terapia , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/diagnóstico por imagem , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/terapia , Imageamento por Ressonância Magnética , Neoplasias Pélvicas/diagnóstico por imagem , Neoplasias Pélvicas/patologia , Neoplasias Pélvicas/terapia , Tomografia Computadorizada por Raios XRESUMO
Broad-range amplification and sequencing of the bacterial 16S rRNA gene directly from clinical specimens are offered as a diagnostic service in many laboratories. One major pitfall is primer cross-reactivity with human DNA which will result in mixed chromatograms. Mixed chromatograms will complicate subsequent sequence analysis and impede identification. In SYBR green real-time PCR assays, it can also affect crossing threshold values and consequently the status of a specimen as positive or negative. We evaluated two conventional primer pairs in common use and a new primer pair based on the dual priming oligonucleotide (DPO) principle. Cross-reactivity was observed when both conventional primer pairs were used, resulting in interpretation difficulties. No cross-reactivity was observed using the DPOs even in specimens with a high ratio of human to bacterial DNA. In addition to reducing cross-reactivity, the DPO principle also offers a high degree of flexibility in the design of primers and should be considered for any PCR assay intended for detection and identification of pathogens directly from human clinical specimens.