• Novel PCR Test to Detect Ocular Infectious Disease Pathogens

    By Jean Shaw and Lynda Seminara and selected by Deepak P. Edward, MD

    Journal Highlights

    Investigative Ophthalmology & Visual Science

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    In an effort to improve on current methods to detect ocular infectious diseases, Nakano et al. developed and evaluated a multiplex solid-phase strip polymerase chain reaction (PCR) for concurrent detection of common pathogens. They found that their novel PCR assay is simple, fast, and reliable.

    The multiplex strip PCR was de­signed to detect 24 common ocular infectious disease pathogens, includ­ing herpes simplex virus (HSV) type 1, HSV type 2, varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), adenovirus, Candida species, and various types of human herpes virus (HHV). The strip PCR was tested with a negative control (distilled water) and a standard positive control (DNA). Its utility was evaluated using infectious and noninfectious oc­ular samples from patients. Cutoffs of quantification cycle values were deter­mined with noninfectious ocular sam­ples to minimize false-positive results. DNA extraction and amplification were performed in different laboratories to avoid potential contamination.

    In infectious samples, the strip test rapidly and effectively detected HSV types 1 and 2, VZV, EBV, CMV, adenovirus, HHV types 6 and 7, human T-cell lymphotropic virus type 1, Propionibacterium acnes, bacterial 16S, Candida species, Aspergillus, fungal 28S, Toxoplasma gondii, Chlamydia trachomatis, and Acanthamoeba. Strip PCR results with distilled water were negative for all items except glyceral­dehyde 3-phosphate dehydrogenase (negative DNA control). Repeatability tests demonstrated the precision of the assay. Sensitivity was comparable to that of quantitative real-time PCR and better than that of capillary-type PCR.

    The authors noted that the multi­plex strip PCR test for simultaneous detection of 24 ocular infectious disease pathogens is quicker and simpler than capillary-type multiplex PCR assays. They believe that the new strip will be especially useful for patients who may acquire unexpected infectious diseases, such as patients who are immunocom­promised because of drug treatment or infection with the human immunodefi­ciency virus. A large, prospective, mul­ticenter study of the assay is planned.

    The original article can be found here.