STD's III

Question 1

describe the life cycle of chlamydia

Answer 1

1- infectious form (elementary body): smaller, metabolically inert, and replicates extracellularly.
2- replicative form (reticulate body): larger, metabolically active, pleomorphism, intracellular -R, and non-infectious.

Question 2

general characteristics of chlamydia (5)

Answer 2

• obligate intracellular bacteria
• gram-negative
• no peptidoglycan layer
• cannot be cultured
• common LPS structure, OMP

Question 3

what are the clinical manifestations of chlamydia in males?

Answer 3

non-specific urethritis, epididymitis, and proctitis.

Question 4

what are the clinical manifestations of chlamydia in females?

Answer 4

Vaginal discharge, cervicitis, salpingitis, ectopic pregnancy.

Question 5

what is lymphogranuloma venerium, what causes it, and how to diagnose it?

Answer 5

• Caused by Chlamydia trachomatis L1, L2, and L3 serotypes.
• characterized by painless genital ulcer followed by suppurative lymphadenopathy
• Frei test used in diagnosis
• Newborn inclusion conjunctivitis→ blindness

Question 6

how to culture chlamydia?

Answer 6

• isolation McCoy cell culture
• stained with fluorescent antibodies to recognize the large intracytoplasmic inclusion.

Question 7

how do you treat chlamydia?

Answer 7

No peptidoglycan layer ( so we can’t use penicillin or beta-lactam antibiotics):
- Tetracycline and doxycycline.
- Macrolides: Erythromycin and azithromycin.
- Ofloxacin.
- Sulfonamide

Question 8

what are the virulence factors of E. coli

Answer 8

• Adherence factors (adhesins)
  Type 1 pili (D-mannose), type p (gal-gal): allow the bacteria to attach to the uroepithelium and colonize it
• K capsular antigens →protect bacteria from phagocytosis

Question 9

how do we collect a urine specimen for E. coli diagnosis?

Answer 9

• clean-voided
  midstream urine.
• Suprapubic aspiration > any growth is significant

Question 10

specimen collection in prostatitis

Answer 10

collect urine in 4 segments (VB1, VB2, EPS ,VB3)
1. VB1 (initial voiding urine) →assess urethritis
2. VB2 (midstream urine) → assess cystitis
3. EPS (expressed prostatic secretions) → assess prostatitis
4. VB3 → post prostatic massage urine specimen →ask the patient to urinate again
(the most important)

Question 11

treatment of UTI caused by E.coli

Answer 11

TMP- SMX (trimethoprim / sulfamethaxazole) → DOC
- Flouroquinolones, Nitrofurantion, empirical therapy.

Question 12

what is the diagnostic test for Candida albicans

Answer 12

Germ tube production test