1. Urogenital flagellates
Mrs. Dalia Kamal Eldien Mohammed
MSC in Microbiology
Lecture NO 6

2. Objectives Classification of Urogenital flagellates
Trichomonas vaginalis as example of urogenital flagellates (distribution, mode of transmission& vector)
Morphology of Trichomonas vaginalis cyst
Life cycle of Trichomonas vaginalis
Clinical significance of Trichomonas vagantitis
Laboratory diagnosis of Trichomonas vaginalis
Treatment

3. Classification Phylum Sarcomastigophora
Subphylum Mastigophora (flagellates)
Class Zoomastigophorea
Order Trichomonadida
Genera Dientamoeba,
Trichomonas.
Pentatrichomonas

4. Urogenital flagellates
Genus Trichomonas is classified into 3 species:
1- Trichomonas hominis: inhabiting the cecal region of the large intestine where the feed on bacteria. It is thought to be non-pathogenic although it has been associated with diarrhoeic stools. It is the most commonly found flagellate next to Giardia lamblia and Dientamoeba fragilis
2- Trichomonas tenax: inhabiting the oral cavity. The typical tenax infection does not produce any notable symptoms. On a rare occasion, T. tenax has been known to invade the respiratory tract, but this appears to have mainly occurred in patients with underlying thoracic or lung abscesses of pleural exudates.
3- Trichomonas vaginalis: inhabiting the female genital tract, also found in the urinary tract of both males and females.

5. Trichomonas vaginalis
Trichomonas vaginalis, worldwide distributed flagellate, is the most common pathogenic protozoan of humans in industrialized countries with the higher prevalence among persons with multiple sexual partners or other venereal diseases.
It could be the only truly sexually transmitted parasitic infection in humans.
The location of the parasite in the host, present in Cervico-vaginal and uro-genital epithelial cells of women and uro-genital cells of men.
No vector in Trichomonas – man is the reservoir host and sexual contact is the primary method of infection.

6. Morphology Trichomonas vaginalis do not have a cystic stage.
The trophozoites measure from µm long Slightly larger than the size of a white blood cell.
It is pear-shaped and has an axostyle which runs from the nucleus down the centre of the body and extends from the end of the body.
The characteristic number of five flagella,  with four that extend outside of the cell and the fifth wrapping backwards along the surface of the organism.
They also have a single nucleus at the anterior end.
Trichomonads swim with a characteristic wobbly (Jerky and unsteady) movement, which makes them unmistakable during diagnosis

8. Life Cycle
Trichomonas vaginalis resides in the female lower genital tract and the male urethra and prostate, where it replicates by binary fission
Is transmitted among humans, its only known host, primarily by sexual intercourse.
The parasite does not appear to have a cyst form, and does not survive well in the external environment

10. Clinical significance
Trichomonas vaginalis infection in women is frequently symptomatic causing vaginitis with a purulent yellow green discharge is the prominent symptom, and can be accompanied by vulvar and cervical lesions, abdominal pain, dysuria .
In men, the infection is frequently asymptomatic; occasionally, urethritis, epididymitis, and prostatitis can occur
Nowadays, it is recognized as a factor in promoting HIV infection, causing low-weight and premature births.
The incubation period is 5 to 28 days.

11. Pathogenesis Infected vaginal discharge can contain 105 protozoa/ml.
T. vaginalis damages epithelial cells upon contact, resulting in microulcerations.
T. vaginalis activates complement therefore attracts neutrophils.
Vaginal discharge, vulvovaginal soreness or irritation. Vaginal odor may be result of coexisting bacterial infection
Parasite induces elevation of vaginal pH from 4.5 to 5.0
Parasite can infect urethra and paraurethral glands causing dysuria. Swelling of prostrate gland in males.
In extreme cases can result in gestational trichomoniasis and vaginal emphysematosa (gas filled blebs in vaginal walls)

12. Symptoms Symptoms in women can include:
Greenish-yellow, frothy vaginal discharge with a strong odor
Painful urination
Vaginal itching and irritation
Discomfort during intercourse
Lower abdominal pain (rare)
Trichomoniasis in pregnant women may cause premature rupture of the membranes that protect the baby, and early delivery. 

13. Most men who have trichomoniasis don’t have any symptoms, but you might notice:
An irritation or burning feeling inside penis.
A discharge from penis.

14. Diagnosis
The most practical and rapid method of diagnosis is the microscopic examination of wet mounts of vaginal secretion and detection of actively motile organisms between the pus cells
Or they can be detected in the sediment of spin down urine for microscopic analysis.
In either case the classic corkscrew motility is looked for when analyzing the specimen. It is very important for this motility to be detected due to the similar size that the parasite has with white blood cells
For this reason it is very important to provide prompt delivery of the specimen to the laboratory for analysis as the absence of motility will prevent the technologist from making the confirmatory identification.

15. Trophozoite

16. Trophozoite

17. Other methods of dignosis include the following: 1- Stain smear with Giemsa or field stain 2- Direct immunofluorescent antibody (DFA) 3- Culture system using Feinberg-Whittington or Diamond’s modified medium or Trichosel medium. 4- Using McCoy cells for the cultivation of T. vaginalis from clinical specimens and showed this method to be superior to the broth culture and wet-mount preparation since it was able to detect T. vaginalis at a concentration as low as 3 organisms/ml. However, cell culture is not routinely performed, because it is expensive and not convenient for rapid diagnosis.

18. 5- Molecular methods are far more sensitive then direct microscopic detection. One molecular method in particular will screen for Candida albicans and Gardnerella vaginalis simultaneously to cover the three major causative agents of vaginitis.

19. Treatment Metronidazole
Effective against anaerobes (bacteria and parasites – Entamoeba hystolitica, Giardia lamblia and Trichomonas)