What are the bacterial Sexually Transmitted Infections (STIs)?

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From the Guidelines

The main bacterial sexually transmitted infections (STIs) are gonorrhea, chlamydia, syphilis, and Mycoplasma genitalium. These infections are caused by the bacteria Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, and Mycoplasma genitalium, respectively 1.

Key Characteristics of Each Infection

  • Gonorrhea: typically treated with dual therapy of ceftriaxone 500mg IM once plus azithromycin 1g orally once
  • Chlamydia: usually treated with doxycycline 100mg twice daily for 7 days or azithromycin 1g as a single dose
  • Syphilis: requires benzathine penicillin G 2.4 million units IM once for early syphilis or weekly for three weeks for late syphilis
  • Mycoplasma genitalium infection: typically treated with doxycycline followed by moxifloxacin

Importance of Screening and Treatment

These bacterial STIs often present with symptoms like discharge, pain during urination, or genital lesions, but can also be asymptomatic, making regular screening essential for sexually active individuals 1. All sexual partners should be notified and treated to prevent reinfection, and patients should abstain from sexual activity until treatment is complete and symptoms resolve. Prompt recognition and appropriate treatment of chlamydial and gonococcal infections are crucial not only in the prevention of STD-associated HIV transmission but also in the primary prevention of STD-related infertility 1.

From the FDA Drug Label

  • Urethritis and cervicitis due to Chlamydia trachomatis or Neisseria gonorrhoeae.
  • Genital ulcer disease in men due to Haemophilus ducreyi (chancroid).
  • Neisseria gonorrhoeae
  • Haemophilus ducreyi

The bacterial STIs listed are:

  • Chlamydia trachomatis
  • Neisseria gonorrhoeae
  • Haemophilus ducreyi 2 Note that other bacterial STIs may exist but are not mentioned in the provided drug labels.

From the Research

Bacterial STIs

The following are some of the bacterial STIs:

  • Chlamydia 3, 4
  • Gonorrhea 3, 4, 5
  • Syphilis 3, 4, 5
  • Mycoplasma genitalium 3, 6, 4, 5
  • Trichomoniasis is not a bacterial infection, it is a protozoan infection 3, 5

Key Characteristics of Bacterial STIs

Some key characteristics of these bacterial STIs include:

  • Asymptomatic infections are frequent 3, 6, 4
  • Transmission occurs through direct mucosal contact 6
  • Symptoms can include urethritis, dysuria, discharge, vaginal discharge, abdominal pain, and dyspareunia 6, 4
  • Diagnosis is achievable through nucleic acid amplification testing 3, 6, 4
  • Treatment options include antibiotics such as ceftriaxone, doxycycline, penicillin, moxifloxacin, and azithromycin 3, 6, 4, 5
  • Antimicrobial resistance is a growing concern, particularly for gonorrhea and Mycoplasma genitalium 3, 6, 4, 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Bacterial sexually transmitted infections.

Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG, 2019

Research

Clinical Updates in Sexually Transmitted Infections, 2024.

Journal of women's health (2002), 2024

Research

2021 European guideline on the management of Mycoplasma genitalium infections.

Journal of the European Academy of Dermatology and Venereology : JEADV, 2022

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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