Trichomonas

Question 1

T. vaginalis

Answer 1

human pathogen

Question 2

T. TENAX

Answer 2

oral/gingival and tracheobroncial site; nnon-pathogenic

Question 3

Peentatrichomonas hominis

Answer 3

intestinal tract; non pathogenic

Question 4

T. FAETUS

Answer 4

bovine, feline, swine population

Question 5

Describe T. vaginalis

Answer 5

• extracellular parasite; does not invade tissue’s mucosal surfaces
• microaerophilic, requires enzymes to neutralize O2 such as sulphur oxide dismutase, reductases, and thioredoxins.
• motile; jerky, rapid movements
• largest known protozoan genome = 6 chromosomes with 60 000 protein coding genes
• receptor med endocytosis to phagocytose human cells, bacteria, yeast to obtain nutrients
• iron = essential element for growth and maintain infection

Question 6

striucture of T. vaginalis troph

Answer 6

• pyriform or pear shape
• 4 anterior flagella
• undulating membrane containing the recurrent flagellum (stops halfway down)
• pelot = chinetosomal complex at anterior of organism from which the costa, recurring flagella and undulating membrane originate
• prominent nucleus
• hydrogenosomes =mitochondria-like; double membrnae, producte ATP and have similar metbaolic activity; using H+ as e- acceptor
• axostyle (ant to posterior)
• 7-23 um long and 5-15 um wide

Question 7

T or F. T. vaginalis has no cyst stage

Answer 7

T

Question 8

life cycle of T. vaginalis

Answer 8

simple long binary fission every 8-12 hours

no cyst stage = vulnerable to harsh environmental conditions

can only survive 20-30 mins in air, but 6-24 hrs in urine, semen and swimming pool water

can grow at a wide pH but optimal is pH 6-6.3

Question 9

epidemiology of T. vaginalis

Answer 9

• humans are only known natural host
• sexual contact = main mode of transmission = STI
• non-sexual transmission not common but can occur with contaminated fomites such as towels, washcloths and bath water

predominates in females (F:M 10:1)

most prevalent non-viral STI worldwide; not reportabe = neglected STI

known to increase acquisition of HIV and shedding of virus

Question 10

pathogenis of T. vagnalis

Answer 10

• contact with host cells - adherent; mediated by surface lipoglycan and membrane proteins => cytoskeletal changed from pear shape to flattened spreading amoeboid shape

amoeboid = key player of pathogenesis

adherence = cytotoxicity; not full understood

local immune response = pro-inflammatory cytokines from urogenital cells; predominantly neutrophils in vaginal discharge; lymps and macs also present

humoral rsponse = IgA (local), M&G too but short-lived and does prevent re-nifections

mucinase allows organism to penetrate mucus barrier, coating epi surfaces of vagina and cervix

adhesins and cytolytic enzymes and proteinases (degrade Igs to make chronic infection)

Question 11

T. vaginalis microbiome

Answer 11

2 Mycoplasma species and some have up to 4 viruses within it => contribute to its pathogenesis and virulence

Question 12

host defense evasion mechanisms of T. vaginalis for chronic infection

Answer 12

• mucinase assists organism in penetrating mucus layer of vagna
• acidic pH of vagina helps with adhesion of organism, then it increases pH once adhered (up fro 4.5)
• T. vag also phagocytose human cells and hot defense proteins
• resistant to complement when in an iron-rich environment
• coats itself with host plasma proteins
• produces surface proteins which are homologous to host proteins
• capable of phenotypic variation
• exosomes induce IL-6 response = downregulation of IL-8 response in ectocervical cell = reduces neuts recruitment

Question 13

females symptoms of T. vaginalis

Answer 13

50-85 % asymptomatic

infection of vagina, cervix. urethra, pelvic cavity; strawberry cervix

may have copious frothy vagina discharge = itchy and foul smelling

can have negative effect on pregnancy

associated with infection in newborn babies (neonatal pneumonia)

Question 14

male symptoms T. vaginalis

Answer 14

70-85% asymptomatic
urethra is affected
can spread to epididymis and prostate glands

Question 15

T or F. T. vaginalis has been implicated as a cause of male and female infertility

Answer 15

T

Question 16

incubation period of T. vaginalis

Answer 16

5-28 days

Question 17

diagnosis of T. vag

Answer 17

light microscopy; wet prep most common
> vag fluid must be examined within 10-20 mins of collection for motility
> highly insensitive

stained smear (Gram or Giemsa) but can distort organisms due to fixation (even lower sensitivity)

can culture = previous gold std on diamond’s media

antigen test

molecular methods (current gold std) = PCR based; targets RNA or DNA of parasite

Question 18

T or F. There has been antimicrobial resistance seen from T. vaginalis

Answer 18

T