Lecture 1 - Hematology and Parasitology (BCh 507) - Protozoology - Damanhour University PDF

Damanhour University Faculty of Science Zoology Department Course: Hematology and Parasitology (BCh 507) Part : Protozoology Lecture 1 Protozoa and Entamoeba sp. Prepared by: Dr. Samir El-Abbassy...

Damanhour University Faculty of Science Zoology Department Course: Hematology and Parasitology (BCh 507) Part : Protozoology Lecture 1 Protozoa and Entamoeba sp. Prepared by: Dr. Samir El-Abbassy 1  Parasitic Protozoa 1-One cell performing all vital functions ( Nutrition, reproduction, respiration, excretion etc…) 2-Mass of protoplasm composed of plasma membrane ,cytoplasm and Nucleus. 3-The cytoplasm is differentiated into an outer layer called ectoplasm and inner layer called endoplasm. 4-Functions of the plasma membrane and ectoplasm are protection, respiration, excretion, locomotion and ingestion.  5-The endoplasm contains nucleus, contractile(excretory) vacuoles and food vacuoles. 6-The nucleus consists of an endosome( karyosome), nuclear envelope, chromatin patches and nuclear fluid. 7-Locomotion : pseudopdia, cilia and flagella. 8-Respiration: aerobic or anaerobic. 9- Excretion and osmoregulation by either diffusion or by contractile vacuoles. 10-Nutrition : absorption of food through the plasma membrane. Solid food is engulfed by pseudopodia (Amaebae,) or ingested through a cytostome (ciliates and flagellates), or by diffusion. 11-Reproduction : A) – Asexual : by binary fission, multiple fission or schizogony and budding. B)- Sexual : * Syngamy : complete fusion of two gametes *Conjugation :Temporary union of two individuals of the same species. 12-Encystement : The trophozoite secretes a cyst around itself to survive outside the host.  Parasitic Protozoa Phylum : Sarcomastigophora 1-E. histolytica :Large intestine of humans. (Pseudopodia) 2-E. coli : Large intestine of humans (Pseudopodia 3- Giardia lambelia: Small intestn (Flagellates 4-Trichomonas vaginalis: urogenital tract ( Flagellates). Phylum : Ciliophor : )Cilia) 1- Balantidium coli :Large intestine of humans. Phylum: Apicompexa (does not possess means of locomotion) 1- Cryptosporidium: Small intestine 2-Toxoplasma gondii: brain, muscles, eyes, and lymph nodes Phylum : Sarcomastigophora 1-E. histolytica : intestine of humans. 2-E. coli : intestine of humans. Morphology of E. histolytica : 2 main forms A- Trophzoite: 12-30um and move with pseudopodium cyoplasm is differentiated into ectoplasm and endoplasm A single nucleus with nuclear membrane , centeric endosome and chromatin patches *Cytoplasm with food Vacuoles containing RBC’s. B-Cyst (10-20um): *Mature cyst contains four nuclei, immature- one or two. *Endosome is small and centrally located. *Cytoplasm contains chromatoid bodies and glycogen vacuole  1-Entamoeba coli morphology The trophozoite :measures 20-40 µm and possesses many pseudopodia.  The cytoplasm is not differentiated into ectoplasm and endoplasm.  It contains a single nucleus with peripheral endosome. The food vacuoles have no erythrocytes but contain bacteria and undigested food. The mature cyst: represents the infective stage and measures 20-30 µm and contains 8 nuclei. E. coli has no pathogenic effects. Morphology of Entamoeba species  Main differences between human Amoebae Charactcer E.histolytica E.coli 1. Habitat Intestine of man Intestine of man 1. Trophozoite A. Size 10-30 µm. 20-40 µm. B. Cytoplasm Differentiated Not differentiated C. Food vacuole With erythrocytes and bacteria With food and bacteria D. Nucleus: Small and centeric Large and eccenteric (peripheral ) Karyosome Present Present 1. Mature cyst Present Present A. Size 10-15 µm. 20-30 µm. B. No. Nuclei Four Eight 1. Disease Pathogenic Non-pathogenic 1. Infective stage Mature cyst Mature cyst Life cycle of E.histolytica Life cycle of E.histolytica 1- In intestine of man, the trophozoite reproduces asexually by binary fission to form trophozoites. 2-The trophozoite performs either virulent(invasive) or non-virulent (noninvasive) cycle. 3- In virulent (invasive) cycle, the trophozoites attack the intestinal wall and pass to blood circulation where they infect some organs like brain, lung and liver. 4- In nonvirulent (noninvasive) cycle, the trophozoite changes to precystic form which makes encystation and forms mononucleate cyst containing a single nucleus, chromatoid bodies and glycogen vacuole. 5- The nucleus of mononucleate cyst reproduces twice to form mature cyst with 4 nuclei, chromatoid bodies and glycogen vacuole (infective stage). 6- The mature cyst comes out with the faeces. 7- Infection takes place by : A- Eating food or drinking water contaminated with the mature cysts. B- Mechanical transmission by flies and cockroaches (which act as vectors of cysts). C- Autoinfection: Feco-oral route (hand to mouth contact). 8- Excystation occurs in intestine and metcystic form with 4 nuclei is formed. 9- The nuclei reproduce by binary fission to form metacyst with 8 nuclei. 10- The cytoplasm divides and 8 trophozoites are formed.  Cytoplasmic division P Binnary Nuclei division fission N FV Metacyst Trophozoite with 8 nuclei 8Trophozoites in intestine Metacyst Brain (with 4 nuclei) Virulent(invasive) cycle Liver Blood Attack circulation intestinal wall 2 Trophozoites Non-virulent Lung (noninvasive cycle) Excystation in CW CB small intestine GV Encystation N Come out Infection by with faeces eating food or drinking water Mature cyst Pre-cystic contaminated with Binucleate Mononucleate with 4nuclei form mature cyst cyst cyst (infective stage) CW=Cyst wall, CB=Chromatoid bodies ,GV=Glycogen vacuole, Life cycle of Entamoeba histolytica FV= Food vacuole, N=Nucleus, P=Pseudopodium, Pathogenesis and symptoms: - Flask-shaped ulcers. - Intestinal amoebiasis (Amoebic dysentery) symptoms: a- Stool containing blood and mucus. b- Abdominal pain. c- Diarrhea with blood. - Secondary extra intestinal amoebiasis: Amoebae are carried from intestinal tissues to extra intestinal organs via the portal circulation producing : * Hepatic amoebiasis in the liver. * Pulmonary amoebiasis in the lung. *Amoebic brain abscess in the brain. Extraintestinal Amebiasis metastasis via blood stream ‫انتقال المرض عبر مجرى الدم‬ primarily liver (portal vein).)‫الكبد هو الموقع األساسي لإلصابة (عبر الوريد البابي‬ other sites less frequent high antibody titers humenhealth.com ‘flasked-shaped ulcer’  Amebic Liver Abscess is caused by infection with the parasite Entamoeba histolytica The abscess forms when trophozoites migrate from the intestines to the liver via the portal circulation. Once in the liver, the parasites destroy liver tissue, leading to the formation of necrotic (dead) areas that accumulate fluid, resulting in an abscess.  Main Causes of Amebic Liver Abscess Trophozoite migration: The parasites move from the intestines to the liver through the portal vein. Tissue destruction: Upon entering the liver, the parasite causes liver cell damage and necrosis. Inflammatory response: The liver mounts an immune response to eliminate the parasite, leading to the accumulation of fluid and pus (which is usually chocolate-colored).  Symptoms of Amebic Liver Abscess  Fever  Pain in the upper right side of the abdomen  Enlarged liver  Weight loss  Amebic Liver Abscess chocolate-colored ‘pus’ necrotic material further metastasis, direct extension or fistula humenhealth.com Diagnosis A) Intestinal amoebiasis: * Examination of unstained faecal saline smear to detect trophozoites and cysts. Examination of faecal stained eosin (0.5%) smears to detect trophozoites and cysts. Examination of faecal stained Iodine (1%) smear to observe the internal organs of both trophozoites and cysts. * Examination of fixed faecal smear stained with iron hematoxiline or trichrome. * Concentration method using Zink sulphate centrifugal floatation technique for detecting the cysts. * Making stool culture to detect cysts. * Making sigmoidoscopy to visualize lesions and take aspirate or biopsy from ulcers to show amoebic trophozoites. * Indirect sero-diagnosis for detection of copro- antigen (i.e. E.histolytica antigens in stool) B) - Extra-intestinal amoebiasis 1- Trophozoites can be detected in: * Aspirates from the liver abscess. * Sputum in case of lung abscess. *Cerebrospinal fluid (C.S.F.) in case of brain abscess. * Radiography for detection of abscess cavities in the liver, lung or brain. *Ultrasonography for liver. Intestinal Flagellates Giardia lambelia Trichomonas vaginalis  Intestinal Flagellates Giardia lambelia Distribution : Cosmopolitan Host : Human Habitat : Small Intestine Morphology Two forms : Trophozoite and Cyst Transmission: By eating food or drinking water contaminated with the mature cyst Owel Giardia lambelia A)Trophozoites (10-20um) Pear-shaped Bilaterally symmetrical 2 nuclei 2 median bodies Four pairs of flagella (one anterior, one posterior,one ventral and one caudal) # Adhesive disc serves for attachment to the mucosal epithelium B) Cyst (10-12um) 4 nuclei. 4 median bodies. 2 ventral grooves.  Adhesive discs(2) Nuclei(2) Cyst wall Nuclei(4) Anterior flagella Ventral grooves(2) Posterior flagella Median bodies(4) Median bodies Ventral flagella Ventral groove B- Mature cyst Infective stage) Caudal flagella A- Trophozoite Infection : by eating food or drinking water contaminated with the mature cyst (infective stage) Morphology of Giardia lambelia  1-GIARDIA LAMBLIA Morphology http://www.k-state.edu/parasitology/  cdc.gov Giardia lamblia trophozoites, as they appear with the scanning electron microscope.  Life cycle of Giardia * Trophozoites reproduce by simple binnary fission * Trophozoites are transformed into cysts(infective stage) * Cysts are passed out with the faeces * Water and food become contaminated with the cysts * Man gets infected by eating food or drinking water contaminated with the mature cysts * In intestine of infected person, excystation occurs and two trophozoites come out of each cyst.  Pathogenicity and clinical picture : 1- Giardiasis causes acute diarrhea. 2-Inflammation in the duodenal wall 3- Abdominal cramps. 4-Abdominal distention 5-Vomiting. 6- Loss of weight 7-In acute stage trophozoites attack liver throug billiary duct and cause Jundice and biliary colic. Laboratory diagnosis: A-Direct stool examination to detect trophozoites &cysts. B- Examination of duodenal aspirate for trophozoites. C-Detection of coproantigen of Giardia using an immunoassay.  Trichomonas vaginalis Distribution : Cosmoplitan Dfinitive host : Humans Intermediate/ vector host : None Habitat : * Man : Urethra, urinary bladder, prostate gland and seminal vesicle * Woman : Vagina, urethra, cervix, uterus and urinary bladder Morphology * Tophozoite and no cyst(17 micron) Morphology It is found only in trophozoite form which measures 17 -20 µm. Trophozoite is pear-shaped and moves by 5 flagellae, 4 anterior and one poaterior forming an undulating membrane with the anterior half of the body. The axostyle extends from the kinetosome region to the posterior region and extends outside the body. The cytoplasm contains one nucleus, one parabasal fibril, one parabasal body and costa.  Anterior flagella (4) Kinetosome Undulating membrane Nucleus Posterior flagellum Parabasal body Coasta Parabasal fibril Axostyle Infection : sexual intercourse Morphology of Trichomonas vaginalis  Transmissin 1-Direct through sexual intercourse 2- Indirectly through the use of contaminated inner clothes, toilet articles and toilet seats. 3- Some infections in babies are acquired while passing through the birth canal of their mothers. Pathogenesis & Clinical picture: Vaginitis (Burning sensation and itching of the vagina & creamy discharge( Inflamation in genital organs of both male and female. Laboratory Diagnosis: 1- Microscopic examination of fresh vaginal discharge,fresh semen, prostatic secretions and urine for trophozoites. 2- Cultures of discharge to detect trophozoite. 3- Immunological tests: A- Direct fluorescent antibody test using labeld monoclonal antibodies. B- Enzyme immunoassay. C-Molecular technique as DNA probe.