Improved diagnoses of Chlamydia trachomatis infections represent a critical unmet medical need. C. trachomatis is an obligate intracellular pathogen of humans that causes blindness, pelvic inflammatory disease, infertility, and is an important cofactor in transmission of human immunodeficiency virus (HIV). Infection rates associated with this pathogen make it the number one bacterial sexually transmitted disease (STD) worldwide. Many of these infections are asymptomatic, contributing to a large, silent epidemic. Current chlamydial diagnostics are primarily based on nucleic acid amplification tests (NAAT) that lack concordance across the different NAATs, vary in sensitivity (although specificity is high), are expensive, require technical expertise, take days for results (especially with batch processing), and are usually confined to major clinical or reference laboratories. They are also unable to differentiate between invasive lymphogranuloma venereum (LGV) versus non-invasive strains D to K, the former of which require weeks of antibiotic therapy for eradication. Network Biosystems (NetBio) is proposing to develop an inexpensive microfluidics-based diagnostic for C. trachomatis, including test-of-cure, that will provide sensitive and specific detection and discrimination of strain types to enable clinical decisions to be made in real time. Development of such an effective point-of-care diagnostic could result in widespread screening efforts for detection of symptomatic and asymptomatic infections and appropriate treatment that would not only reduce the acute and chronic morbidity that is directly associated with these infections but could also reduce potential collateral risks associated with C. trachomatis infections, including HIV-1 infection, cervical cancer and autoimmune-driven arthritis.
The Specific Aims, then, of this Phase I application are to: 1) Develop a rapid method for genomic DNA extraction from clinical urethral and cervical samples;2) Design at least two primer pairs that are sensitive and specific for C. trachomatis amplification at two loci;and 3) Determine the sensitivity and specificity of the microfluidics diagnostic for C. trachomatis compared to a current NAAT. In the SBIR Phase II, we will: 1) Expand our methods to extract genomic DNA from conjunctival, pharyngeal, urine, ulcer, vaginal and rectal samples;2) Expand our primer design to identify strain types based on comparative genomics of reference and clinical chlamydial STD strains (essential for directing therapy for invasive versus non-invasive C. trachomatis strains and for epidemiologic studies);3) Secure patents for FDA approval;4) Design a head-to-head clinical study of our diagnostic against leading commercial diagnostics using clinical samples from diverse geographic populations at risk for chlamydial STDs. Given the genomic expertise of Drs. Tim Read and Deborah Dean for developing target gene primer pairs and the chlamydial STD expertise of Dr. Dean, the application provides a unique collaborative opportunity to finally obtain a rapid point-of-care diagnostic for C. trachomatis.
Chlamydia trachomatis is the leading bacterial cause of sexually transmitted diseases worldwide. Many of these infections are asymptomatic and go undetected, which leads to increased transmission and the sequelae of pelvic inflammatory disease, infertility and ectopic pregnancy. Current diagnostics require extensive technical expertise, are expensive and take days for results, leading to loss of follow up. Additionally, more dangerous strains that require longer treatment cannot be detected. Network Biosystems aims to develop an easy to use, cost effective, one hour diagnostic for C. trachomatis that also differentiates strains types for appropriate treatment.
| Dean, Deborah; Turingan, Rosemary S; Thomann, Hans-Ulrich et al. (2012) A multiplexed microfluidic PCR assay for sensitive and specific point-of-care detection of Chlamydia trachomatis. PLoS One 7:e51685 |
