Bacterial Infections of the Genital Tract

Bacterial Infections of the Genital Tract

• Sexually transmitted infections (STIs) or sexually transmitted diseases (STDs) often lack initial symptoms.
• Common symptoms include vaginal or penile discharge, ulcers on genitals, and pelvic pain.
• Over 30 different pathogens, including bacteria, viruses, and parasites, can cause STIs.
• Key bacterial STIs include Chlamydia trachomatis, Neisseria gonorrhoeae, Klebsiella granulomatis, Mycoplasma genitalium, Mycoplasma hominis, Treponema pallidum, and Ureaplasma.

Transmission of STIs

• Most STIs spread through sexual contact; some can be transmitted via contaminated blood, breastfeeding, or childbirth.

Genus Neisseria

• Contains gram-negative aerobic cocci; includes pathogenic species Neisseria gonorrhoeae and Neisseria meningitidis.
• Gonococcus causes gonorrhea; meningococcus is associated with meningitis.
• Both species are non-motile diplococci and difficult to distinguish microscopically but differ by sugar-use patterns.

Neisseria gonorrhoeae

• Responsible for gonorrhea, a highly reported infectious disease.
• Infections often observed with gram-negative diplococci within neutrophils in clinical samples.
• Transmitted primarily through sexual contact and during childbirth.
• Highly sensitive to dehydration, limiting survival outside the human body.

Laboratory Identification of Gonorrhea

• In males, a smear showing numerous neutrophils and gram-negative diplococci suggests gonorrheal infection; treatment is indicated.
• In females and non-urethral sites in males, positive culture is necessary for diagnosis.

Growth Conditions and Media

• N. gonorrhoeae thrives in aerobic conditions; requires CO2 for optimal growth.
• Selective media like Thayer-Martin agar is essential for isolating gonococci from normal flora.

Chlamydia trachomatis

• Major cause of STIs and the most commonly reported infectious disease worldwide.
• Symptoms include abnormal discharge and painful urination, with many cases being asymptomatic.
• Can lead to serious complications, such as pelvic inflammatory disease (PID) if untreated.

Laboratory Identification of Chlamydia

• Diagnosed via direct tests (fluorescent antibody staining for cellular inclusions) or culturing in human cell lines.
• DNA amplification techniques demonstrate high sensitivity for detection in urine specimens.

Treponema pallidum (Syphilis)

• Caused by Treponema pallidum subspecies pallidum; known for four stages: primary, secondary, latent, and tertiary.
• Primary symptoms: painless chancre; secondary: diffuse rash; tertiary: gummas and potential neurological damage.
• Transmission occurs through sexual contact or from mother to fetus.

Laboratory Identification of Syphilis

• Challenging to diagnose early; diagnosed through blood tests or dark-field microscopy for treponemes in lesions.
• Blood tests classify as non-treponemal (false positives common) and treponemal (for confirmation).

Other Bacterial Infections

• Genital tract infections can manifest as genital discharge or ulceration:
  • Neisseria gonorrhoeae: Gonorrhea
  • Chlamydia trachomatis: Urethritis, cervicitis, Lymphogranuloma venereum (LGV)
  • Ureaplasma: Urethritis
  • Gardnerella vaginalis: Vaginitis
  • Treponema pallidum: Syphilis

Neurosyphilis Diagnosis

• Confirmed by elevated leukocyte counts (lymphocytes) and high protein levels in cerebrospinal fluid in known syphilis patients.

This quiz covers the key bacterial infections affecting the genital tract, focusing on STIs such as Chlamydia and Gonorrhea. Learn about their symptoms, transmission methods, and the pathogens responsible for these sexually transmitted diseases. Test your knowledge on the Genus Neisseria and its role in STIs.