Backgrounds Urine is used for screening STI infections with molecular assays. Copan developed the eNat, a molecular medium that preserves and stabilises nucleic acid (NC), for collection, and storage of clinical specimens for microbial detection by real-time PCR. Seegene uses dry container (DC) for urine collection for detection of urogenital pathogens with the Anyplex II STI-7 (STI7).
Study objective was to validate the eNat for nucleic acid preservation in urines for STDs detection with the STI7 assays.
Methods In this study, 80 urines, collected in DC from patients attending a Milan STD clinic. Urines were tested as per current method and after adding urine to 1ml eNat. To find the urine volume with same sensitivity as urine in DC, 1, 2, and 3ml urine in 1 ml eNAT were tested. After vortexing the eNAT samples, NC was extracted from 350ul with the Automated Purification Systems (NIMBUS IVD) and eluted in 100ul buffer. Purified NCs were tested with the with the Seegene STI7 assay.
Results In the 80 urine samples tested, 43 negative and 37 positive were detected with DC, while 1 ml, 2 ml and 3 ml urine in eNAT detected 45.40.40 negative or partial negative (1, 2, 3) and 35.40.40 positive (1, 2, 3) respectively. More co-infections were detected with eNAT 3 ml. Loss of sensitivity with 1 ml eNAT and inhibition with DC versus 3 ml in eNAT was detected in 7 samples.
Conclusions Good agreement was found between Copan eNat-3 ml urine and urine in DC for the detection of 7 STI with the Seegene assay. Copan eNAT, is available in leak proof tube, easy to transport-store urines, prevents bacterial overgrowth, stabilises NC at RT and is compatible with the STI7 assay.