Trichomonas and Giardia - Lecture Slides |, Study notes of Bacteriology

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Trichomonads andTrichomonads and

Giardia Giardia

Chapters 5 and 6 Chapters 5 and 6

Flagellated Protozoa

Phylum: Parabasalia /Axostylata

Order: Trichomonadida

Trichomonas

Trichomona foetus

• (^) Definitive host spectrum
  • (^) primarily in cattle; occationally in pig, horse, deer
• (^) Geographic distribution
  • (^) Cosmopolitan, costing a conservative $650 million annually in the US alone.
• (^) Sites of infection
  • (^) vagina, uterine tract; preputial cavity
• (^) Pathogenesis/clinical signs
  • (^) male (bull) usually asymptomatic; female may have vaginitis; ascending infection to uterus resulting in placentitis; abortion in first trimester; usually have difficulty with conception if trichomonads remain, rendering animal potential sterile.

Diagnosis

• (^) Direct examination of material from the

reproductive tract or prepuse.

• (^) Inoculation of culture media (48 hr) to

increase the number of trichomonads present

• (^) PCR (polymerase chain reaction) of DNA

from reproductive tract.

• (^) Can also examine aborted fetus, amniotic

fluids, digestive tract, and placenta.

Trichomona vaginalis

• (^) Trichomonas vaginalis is a

sexually transmitted disease

(STD) for humans, although

transmission by other routes

(such as soiled towels) have

been documented. There is

no cyst stage in the life

cycle, so transmission is

direct via the trophozoite

stage).

Trichomoniasis in humans

• (^) Found Worldwide
• (^) 10-15% of women are infected worldwide.
• (^) Males are assumed to be similar, but data lacking.
• (^) Most people infected with trichomoniasis are asymptomatic.
• (^) If symptoms present, then characterized by a white discharge from the genital tract and itching.

Control

• (^) Treatment
  • (^) Treat infected woman
  • (^) Treat her sexual partner(s)
  • (^) Use a condom during future sexual intercourse
• (^) Control limited to symptomatic woman and their

partners. (All ♂ and most ♀ are asymptomatic)

• (^) Drugs used:
  • (^) Quinolines, Arsonic acid, Tetracyclines
  • (^) Metronidazole (low risk of cancer, but very effective)

Trichomona gallinae

• (^) Common name : Canker (chickens)
• (^) Definitive host spectrum
  • (^) avian spp., esp. in pigeons and doves, although poultry and the golden eagle may become infected
• (^) Sites of infection
  • (^) crop, esophagus
• (^) Pathogenesis/clinical signs
  • (^) earliest lesions appear as small ulcers in crop which later extend and coalesce; may involve liver, lungs; life- threatening in chicks and chronic to asymptomatic in adults

Flagellated Protozoa

Phylum Retortamonada Phylum Retortamonada

Order Diplomonidida Order Diplomonidida

Giardia Giardia

Giardia duodenalis – “ Giardiasis”

• (^) Giardia duodenalis = G. intestinalis, G. lamblia
• (^) Geography – Cosmopolitan
  • (^) Estimate 7% of North America is infested
  • (^) Giardia – The most common flagellate of

the human digestive tract.

• (^) Most common waterborne illness in United

States (100,000 to 1 million infections

annually).

Giardia duodenalis

• (^) Morphology of Trophozoite
  • (^) trophozoite = (trof-eh-ZO-ite) Active feeding stage (as opposed to inactive cyst stage)
  • (^) Size : about 15 μm in length
  • (^) General shape: Have a distinct "tear-drop" shape and two nuclei at the anterior end.

Giardia duodenalis

• (^) The two nuclei make

the protozoa look like

its staring back with

“eyes”.

• (^) Because of tear drop

shape, two nuclei, and

flagella, G. duodenalis

is one of the “easiest”

intestinal protozoans of

humans to diagnose.

Giardia duodenalis trophozoites, as seen by a scanning electron microscope. Original image by Arturo Gonzalez, CINVESTAV, Mexico. Used with permission of Javier Ambrosio, UNAM, Mexico.

Giardia duodenalis

• (^) The cysts are about 13

μm in length, oval, and

contain two nuclei (or

four) like the

trophozoites.

What you actually see