False-positive PCR detection of cyclovirus Malawi strain VS5700009 in XXXX cerebrospinal fluid.

@entity1 @entity4334 @entity62877
BACKGROUND: Cyclovirus (CyCV) Malawi strain VS5700009 has recently been discovered and reported in clinical cerebrospinal fluid (CSF) samples. Further epidemiological and case-control studies are warranted. The availability of a highly sensitive and specific detection assay for this new virus is thus crucial. OBJECTIVES: To evaluate the performance of the first and the only available PCR assay for CyCV-VS5700009. STUDY DESIGN: A total of 100 CSF samples collected during January-December 2010 were selected for PCR detection of CyCV-VS5700009. Positive PCR amplicons were subjected to sequencing confirmation and BLAST analysis. RESULTS: Initial PCR screening for CyCV-VS5700009 identified one sample, showing a PCR band of expected size (380 bp). Sequencing and BLAST analysis, however, indicated that the band was 364 bp in length and showed >99% @entity4334 homology to a @entity1 gene known as @entity62877 ( @entity62877 ). Pairwise sequence alignment confirmed that both the forward and reverse PCR primers used had significant homology (>70%) to @entity62877 . None of the CSF samples tested were positive for CyCV-VS5700009. CONCLUSIONS: The original PCR assay for CyCV-VS5700009 detection may have potential cross-reactivity with contaminating @entity1 genomic DNA. The assay may be of little diagnostic use on clinical specimens that are rich in host DNA such as biopsy tissues.
