Background
Sexually Transmitted Infections (STIs) have a significant impact on sexual and reproductive health, with the World Health Organisation reporting more than 1 million STIs being acquired on a daily basis. The four most commonly reported STIs are chlamydia, gonorrhoea, syphilis and trichomoniasis. Other pathogens of STI include Mycoplasma spp., Ureaplasma spp. and herpes simplex virus. We have developed a novel 3base™ real-time PCR (RT-PCR) assay to detect the presence of 12 most significant and commonly encountered STIs in less than 4 hours from primary patient material. The EasyScreen™ STI Assay is a simple and rapid molecular method that utilises 3base™ technology to modify the 4 usual DNA bases into only 3 bases (A, T, G) via a novel, patented bisulphite conversion step.
Methods/Materials
The nucleic acids were converted to a 3base™ form during the DNA isolation in order to yield better multiplexed PCR performance. The assay sensitivity was determined using quantified genomic DNA controls from Vircell and assay performance assessed by using reference material from ATCC, Zeptometrix and QCMD. The clinical performance of the assay was assessed by using over 800 clinical isolates obtained from St. Vincent’s Hospital. DNA extraction and PCR set up was performed on a GS1 automated extraction platform resulting in a significant reduction in hands on time. PCR was performed on a CFX real-time PCR instrument with integrated software calling.
Results
The EasyScreen™ STI Assay is highly specific with no cross reactivity observed. There was 100% concordance with all targets including CT/NG and HSVs compared to conventional molecular methods used at the hospital. 25.1% of mixed infections were easily detected using the EasyScreen™ STI Assay.
Conclusions
The EasyScreenTM STI assay provides a sensitive and specific alternative for the detection of STI pathogens. The workflow from sample processing to results requires less than 4 hours with minimal hands on time. This is particularly advantageous not just for high-throughput pathology laboratories but also in improving patient diagnosis and management.