STI Pathogen Identification and Antibiotic Susceptibility Testing with PCR Technology

STI Pathogen Identification and Antibiotic Susceptibility Testing with PCR Technology

At Medarbor Diagnostics, we’re committed to revolutionizing sexual health diagnostics. Our cutting-edge PCR-based tests not only detect key sexually transmitted organisms but also provide critical information about antibiotic susceptibility. Because there are a large number of STD pathogens which can generate coinfections, their simultaneous detection in a unique sample is very important. Polymerase chain reaction (PCR) is an advanced method of molecular biology which allows for simultaneous detection of multiple pathogens in the same sample.

Specimen Types

  • Urine in C&S Tube
  • E-Swab (Oral swab, rectal swab, vaginal swab)
  • Cervical Brush w/ Pap Smear media

Turnaround time:

  • 24 hour turn-around time from the time the lab receives the sample

We know better patient outcomes are achieved through Fast, Accurate and Reliable laboratory results.

Clinical Significance of Target Organisms

1. Neisseria gonorrhoeae (Gonorrhea):

Why It Matters:

  • Gonorrhea is a prevalent bacterial STI affecting both men and women.
  • It can cause urethritis, cervicitis, and pelvic inflammatory disease (PID).
  • Untreated gonorrhea can lead to serious complications, including infertility and disseminated infections.
  • The CDC recognizes drug-resistant N. gonorrhoeae as an urgent public health concern.
  • Rapid development of resistance necessitates judicious antibiotic use.

Our Approach:

  • Our PCR test detects N. gonorrhoeae DNA directly in the sample.
  • Early identification allows for timely treatment and prevention of complications.
  • Our assay aligns with the UK national guideline for N. gonorrhoeae management.
  • At initial diagnosis, we assess the gyrA S91 mutation status using PCR.
  • Wild-type strains predict sensitivity to ciprofloxacin, guiding treatment decisions.

2. Chlamydia trachomatis (Chlamydia):

Why It Matters:

  • Chlamydia is the most common bacterial STI globally.
  • Often asymptomatic, it can cause pelvic inflammatory disease, tubal scarring, and infertility.

Our Approach:

  • Our PCR assay accurately detects C. trachomatis DNA directly in the sample.
  • Early diagnosis facilitates prompt intervention.

3. Mycoplasma Genitalium:

Why It Matters:

  • M. genitalium is an emerging STI associated with urethritis and cervicitis.
  • It can be resistant to common antibiotics such as Macrolide, necessitating tailored treatment.
  • Empiric therapy with macrolides is risky due to prevalent resistance.

Our Approach:

  • Our PCR test identifies M. genitalium DNA directly in the sample.
  • Combined with antibiotic susceptibility testing, we guide clinicians toward effective therapies.
  • We target 23S rRNA mutations (A2058T, A2058C, A2058G, A2059G).
  • Wild-type variants predict sensitivity to doxycycline–azithromycin.
  • Detection of variants suggests doxycycline–moxifloxacin treatment.

4. Trichomonas vaginalis (Trichomoniasis):

Why It Matters:

  • Trichomoniasis often goes undiagnosed.
  • It causes vaginitis, urethritis, and adverse pregnancy outcomes.

Our Approach:

  • Our PCR assay sensitively detects T. vaginalis DNA.
  • Early identification enables targeted therapy.

Benefits of PCR-Based Antibiotic Susceptibility Testing:


  • PCR offers unparalleled sensitivity and specificity.
  • It detects even low levels of pathogen DNA.
  • PCR identifies specific genetic markers associated with antibiotic resistance.
  • Clinicians make informed decisions, avoiding unnecessary broad-spectrum antibiotics.

Rapid Turnaround Time:

  • Results within 24 hours allow for swift clinical decision-making.
  • Early treatment initiation prevents complications.

Comprehensive Reports for effective treatments:

  • Our detailed reports empower clinicians with actionable information.
  • Antibiotic susceptibility data guide personalized treatment plans.
  • Effective antibiotics are prescribed, minimizing treatment failures.
  • Single-dose oral ciprofloxacin, guided by gyrA 91 genotyping, proves highly effective against N. gonorrhoeae infections.

Reduced Resistance Emergence:

  • By avoiding inappropriate antibiotics, we contribute to combating resistance.
  • Rational use preserves last-line options for severe infections.

Reference: CDC. Antibiotic Resistance Threats in the United States 2019. : Fifer, H., Saunders, J., Soni, S., Sadiq, S. T., & FitzGerald, M. (2020). UK national guideline for the management of infection with Neisseria gonorrhoeae. International Journal of STD & AIDS, 31(1), 4–15. : Ebeyan, S. et al. (2019). Evaluation of the ResistancePlus GC (beta) assay: a commercial diagnostic test for the direct detection of ciprofloxacin susceptibility or resistance in Neisseria gonorrhoeae. Journal of Antimicrobial Chemotherapy, 74(7), 1820–1824. Resistance-Guided Treatment of Gonorrhea: A Prospective Clinical Study. Clin Infect Dis. 2021 Jul 15;73(2):298-303.