topic empat belas protozoa parasites parasitology

parasite

1. TOPIC 12: PROTOZOA NS1122 BASIC SCIENCE 3: PARASITOLOGY DIPLOMA IN NURSING MDM SITI BAINUN BINTI MOHD DALI

2. LEARNING OUTCOME At the end of this lecture, students should be able to: Identify characteristics of protozoa Describe FOUR different classification of protozoa Identify and explain the morphology, life cycles, diseases, symptom, prevention of the amoeba and flagellate parasites

3. INTRODUCTION One-celled animals Infections of protozoa can be ranged form asymptomatic to life threatening

4. GENERAL CHARACTERISTICS OF PROTOZOA They are motile and can move by: Cilia – tiny hair like structure Flagella – long thread-like structures that extend from the cell surface Amoeboid movement – organism moves by sending out pseudopodia

5. CILIA

6. FLAGELLA

7. Ameboid movement

8. GENERAL CHARACTERISTICS OF PROTOZOA Habitat: found in aquatic environment; freshwater or oceans Size and shape: vary greatly Lack a rigid cell wall; flexible and found in various shapes Nutrition They ingest foods by phagocytosis Reproduction: Reproduce by asexual means. Multiply by binary fission, longitudinal fission, transverse fission or budding

9. Budding

10. CLASSIFICATION OF PROTOZOAN PARASITES Protozoan parasites of medical importance can be classifies into FOUR (4) broad groups: Amoeba: structurally simple and can assume any shape. Eg : Entamoeba Histolytica Flagellates: possess whip-like appendages called flagella which are organs of locomotion. Eg : Trypsonoma brucei, Trypsonoma cruzi , Leshmania donovani , Leshmana tropica , Leshmania brasiliensi , Giardia lamblia, Trichomonas vaginalis Sporozoa : characterized by production of spore-like oocysts containing sporozoites. Eg : plasmodium sp., Toxoplasma gondii, Cryptosporidium parvum Ciliates: motile by means of cilia which cover their entire body surface. Eg : Balantidium coli.

11. amoebae

12. INTESTINAL AMOEBAE There are six (6) types of amoeba: Entamoeba histolytica Entamoeba coli Entamoeba hartmanni Endolimax nana Iodamoeba butschii Blastocystis hominis The only truly significant pathogen among amoeba is Entamoeba histolytica.

13. ENTAMOEBA HISTOLYTICA

14. MORPHOLOGY E. histolytica exists in three forms: Active trophozoites Inactive cyst Intermediate precyst

15. 1. Trophozoites 10-60 µm Cytoplasm : finely granular, may contain inclusions. Differentiated into: Ectoplasm: clear with well developed pseudopodia Endoplasm: dense and fine granular enclosing Nucleus: spherical and 4 µm containing central karyosome and peripheral evenly distributed small chromatin dots Food vacuoles : containing leukocytes – bacteria- RBCs

16. 2. Precyst 10 - 20 µm Round or oval with a blunt pseudopodia Absent cyst wall Single nucleus present and endoplasm free from RBC

17. 3. Cyst Round and 10-20 µm average It is surrounded by highly refractile membrane called cyst wall Nuclear structure is similar to trophozoite Four nuclei are present in mature quadrinucleated cyst Glycogen mass and chromatoid bodies are present in immature cysts – disappear in mature ones

18. LIFE CYCLE

19. TRANSMISSION AND PATHOGENESIS Infective form : mature quadrinucleated cyst passed in faeces of convalescents and carriers Transmission as sexually transmitted disease by male homosexual has occurred. Mode of transmission : man acquires infection by swallowing food and water contaminated with cyst Cyst wall is resistant to gastric juice. Incubation period: several days to months

20. TRANSMISSION AND PATHOGENESIS Symptoms: Abdominal pain and diarrhea Bloody diarrhea may ensue when dysentery develops Ulcers in appendix, cecum and other parts of colon May invade wall of colon and enter circulation, and spread hematogenous  extra intestinal abscesses Multiple amoebic abscesses : especially in liver, brain or lung

21. LABORATORY DIAGNOSIS Stool examination L trophozoites are found in diarrheic stool. Cysts are found in formed stool Wet preparation Iodine stained Permanent stain with iron haematoxylin or trichome Concentration techniques for cysts Culture studies Serological tests Proctosigmoidoscopy Liver biopsy Metronidazole Chloroquine Tinidazole Dialoxanide furoate Emetine Secnidazole TREATMENT

22. FLAGELLATES

23. Giardia lamblia

24. MORPHOLOGY Giardia lamblia occurs in TWO (2) forms: Trophozoite Cyst

25. 1. Trophozoite In flat view racket -shaped Side view resembles a split pear Bilateral symmetrical 14µm long and 7µm broad Anterior end broad Contains two axostyles , two nuclei, four pairs of flagella and two sausage-shaped parabasal bodies

26. 2. Cyst Oval shaped 12 µm long and 7 µm broad Axostyle lie diagonally 4 nuclei Remaining flagella and margin of the sucking disc

27. LIFE CYCLE

28. LIFE CYCLE Giardia cysts swallowed form contaminated water, food, hands, surface or objects. Each Giardia cysts releases two trophozoites through process excystation once they reached the small intestine . The trophozoites feed off and absorb nutrients from infected person Giardia trophozoites multiply by longitudinal binary fission , they remain in small intestine: free or attached inside lining of small intestine Giardia trophozoites then move toward the colon and transform intro cyst form through process called encystation . Cyst stage most commonly found in stool Both trophozoites and cyst can be found in stool , and be microscopically diagnosable. Cyst stage can survive several months in cold water or soil.

29. TRANSMISSION AND PATHOGENESIS Found world widely in: Mammals including humans Water source; ponds, lakes, streams, etc Contaminated fruit and raw vegetables Generally resistance to chlorine, filtration is necessary to eliminate contamination Mode of transmission : eat or drink contaminated food source, person-to-person contact trough oral-anal sexual practices Incubation period: 2 – 3 weeks

30. TRANSMISSION AND PATHOGENESIS Symptoms: Watery, foul-smelling diarrhea Abdominal cramps Flatulence Anorexia Nausea Fat-soluble vitamin deficiency, folic acids deficiency Hypoproteinemia , with hypogammaglobulinemia Structural change in intestine villi In severe case, malabsorption syndrome occur Weight loss Patient are often asymptomatic

31. LABORATORY DIAGNOSIS Stool examination Immunofluorescence ELISA PCR Metronidazole Chloroquine Tinidazole Secnidazole Ornidazole TREATMENT

32. Trichomonas vaginalis

33. MORPHOLOGY Trichomonas vaginalis occurs in trophozoite form only

34. 1. Trophozoite Round anterior end, tapered posterior end 4-6 flagella originate from anterior end Undulating membrane halfway down the side Axostyle Evenly distributed chromatin Single nucleus In wet preps, parasite exhibit jerky and rapid moves

35. LIFE CYCLE Trichomonas vaginalis does not appear to have a cyst form They do not survive well in the external environment

36. LIFE CYCLE

37. TRANSMISSION AND PATHOGENESIS Infection is known as trichomoniasis Mode of transmission : sexual contact Incubation period: 5 to 28 days

38. TRANSMISSION AND PATHOGENESIS Symptoms IN WOMEN Burning, itching and irritation Produce foul-smelling, yellow discharge Red lesion on vulvar and cervical Abdominal pain Dysuria IN MEN Urethritis Prostatitis In severe case, prostate tenderness and swelling

39. LABORATORY DIAGNOSIS Microscopic examination of wet mounts Immunofluorescent Culture Metronidazole Prevention by avoidance of unprotected sex, as well as prompt treatment and diagnosis of asymptomatic men TREATMENT

40. Leishmania spp.

41. INTRODUCTION Flagellated protozoa that parasitize the blood and tissues of human host They are known as hemoflagellates Transmitted by insects vector Endemic in parts on India, China, South America, Africa and southern Europe

42. Leishmania PARASITES AND DISEASES

43. MORPHOLOGY Depending on the species, may exist in two or more of the four morphologic forms: Amastigote Promastigote Epimastigote Trypomastigote

44. LIFE CYCLE

45. LIFE CYCLE Sandflies inject the infective stage ( Promastigotes ) from their proboscis during blood meals Promastigotes that reach the puncture wound are phagocytized by macrophages Promastigotes transform in these cells into the tissue stage of the parasite ( amastigotes) Amastigotes multiply by simple division and proceeds to infect other mononuclear phagocytic cells Parasites, host, and other factors affect whether the infection becomes symptomatic and whether cutaneous or visceral leishmaniasis results Sandflies become infected by ingesting infected cells during blood meals In sandflies, amastigotes transform into promastigotes and develop in the gut Promastigote the migrate to the proboscis

46. TRANSMISSION AND PATHOGENESIS Mode of transmission : introduced into the skin by the bite of an infected sandfly, promastigotes Incubation period: vary, from several weeks to as long as three years Infection can result in two main forms; cutaneous leishmaniasis and visceral leishmaniasis (Kala-azar), depending on the Leishmania spp.

47. TRANSMISSION AND PATHOGENESIS Cutaneous leishmaniasis Lesion on areas where sandflies fed Have one or more sores on their skin Sores can change in size and shape over the time sores looked like volcano, with raised edge and central crater Scab covers some sores Sores can be painless or painful Some people have swollen glands near the sores Visceral leishmaniasis Fever Weight loss Enlarged spleen and liver Swollen glands Certain blood tests are abnormal; low RBCs, low WBCs, low platelet count Develop post kala-azar dermal leishmaniasis

48. LABORATORY DIAGNOSIS Microscopic examination of tissue specimen Isoenzyme analysis Serology Molecular diagnosis Depends on part on host and parasite factors TREATMENT

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