Trichomonas vaginalis

Question 1

Trichomonas vaginalis

Answer 1

• extracellular organism
• faculatative anaerobe/ mricroerophilic
• motile with rapid and jerky movements
• has the largest genome of proteazoans, 6 chromosomes)
• can phagocytose human cells, bacteria, and yeast cells
• Needs Fe for growth and maintence of infection (human vagina is Fe rich)
• increases the aquisision of HIV and increases the shedding of HIV viruses

Question 2

Describe the morphology of Trichomonas vaginalis.

Answer 2

• pyriform shape in culture
• 4 anterior flagella
• undulating membrane containing the recurrent flagellum
• has a prominent nucleus
• no mitochondria, has a hydrogenosomes
• 7-23 um long and 5-15um wide

Question 3

Describe the lifecycle of Trichomonias.

Answer 3

1. Trophozoite form in vaginal and prostatic secretes and in the urine multiplys via longitudial binary fission
2. The trophozoite in vagina/ urethracan infect a new host via sexual contact/ formites

Question 4

How long can Trichomonas vaginalis survive in the enviroment?

Answer 4

Air: 5-20 min
Urine/seman/ vaginal fluid/ swimming pool: 6-24 hours

optimal pH: 6-6.3

Question 5

Who is the host for Trichomonas vaginalis?

Answer 5

Humans are the only natural host

Question 6

Describe the pathogenesis of Trichomonas vaginalis.

Answer 6

• when it comes in contact with human cells it changes in morphology as it adheres (flattens) and spreads over the host cells
• Disrupts the host tissue allowing it to attach to host basement membrane proteins (fibronectin and laminin)
• Urogenital cells release proinflammatory cytokines causeing the recruitment of neutrophils, immunity is short lived and IgA,IgM, and IgG is detected in woman
• Virulence factors include: mucinase (penetrates epithelial layer), adhesins, cytolytic enzymes, and proteinases (degrade immunoglobulins)

Question 7

What are the host defense evasion mechanisms?

Answer 7

• mucinase assists the organism in penetrating the tick mucous layer coating the vagina and cervix
• acidic pH in the vagina helps with adhesion of organism and the pH increases after adhesion
  -can phagocytose human cells ad defense proteins
• coats itself with host plasma proteins and produces surface proteins that are homologous to host proetins
• capable of phenotypic variation
• downregulates the IL-8 response in ectocervical cells

Question 8

Describe the clinical manifestations of Trichomonas vaginalis.

Answer 8

Female: 50-85% symptomatic, infects the vagina, cervix, urethra, and pelvic cavity, may have copious frothy vaginal discharge which is itch and foul smelling, can have negative effects on pregnancy, and is associated with infection of newborn babies

Male: 70-85% asymptomatic, infection of urthethra, can spread to the epidymis and prostate gland

Implicated as a cause of male/femal infertility

Question 9

How is a Trichomonas vaginalis infection diagnosed?

Answer 9

• microscopy of wet mounts of vaginal fluids (within 10-20 min after collection) stained with Gram or Giesma
• culture on dimonds media
• antigen tests
• molecular methods such as PCR

Question 10

How is a Trichomonas vaginalis infection treated?

Answer 10

• single dose of antibiotics (most often) and a 7 day course may be required for reccurent disease
  -AMR detected