Parasitology PDF - Topic IV: Flagellates

TOPIC IV: FLAGELLATES INTESTINAL AND GENITAL FLAGELLATES TAXONOMY Species are lumen parasites KINGDOM Animalia Species are non-tissue parasites but at times...

TOPIC IV: FLAGELLATES INTESTINAL AND GENITAL FLAGELLATES TAXONOMY Species are lumen parasites KINGDOM Animalia Species are non-tissue parasites but at times G.lablia in the duodenum and T.vaginalis in SUBKINGDOM Protozoa the vagina erode the epithelial lining of their PHYLUM Sarcomastigaphora respective organs and evolve symptoms. SUBPHYLUM Mastigophora CLASS Zoomastigophora INTESTINAL FLAGELLATE ORDER Diplomonadida FAMILY Hexamitidae GIARDIA DUODENALIS GENUS Giardia Traveller’s diarrhea SPECIES Lamblia Beaver Fever Steatorrhea Malabsorption Syndrome HISTORY Gay Bowel Syndrome 1681- 1ST o by Antoine van Leeuwenhoek in his INTRODUCTION stool. Classified as Flagellates 1859 – 1st Easily recognized because they have two (2) o discovered by Lambl and called it identical nuclei lying side by side. Cercomonas intestinalis Movement is made possible by the presence of 1915 flagella o Stiles later renamed it to Giardia lamblia Widespread occurrence causing infections in people from all nations and socioeconomic levels Lacks mitochondira and golgi apparatus Lives in the duodenum, jejunum, and upper ileum of humans Of worlwide distribution (cosmopolitan) Prevalence is associated w/ poor environmental sanitation Also attributed to homosexual oro- anal practices (“Gay bowel syndrome”) Common source outbreaks are almost exclusively water-borne Exists in bothe trophozoite and cyst forms A PATHOGENIC flagellate (Traveler’s Diarrhea and Gardiasis) Has “Falling Leaf” motility Commonly found in FLUID STOOLS MORPHOLOGY OTHER NAMES Giardia lamblia TROPHOZOITE Giardia intestinalis 9-12 um long by 5-25 um wide Cercomonas intestinalis Pyriform or teardrop shaped, pointed posteriously Bilaterally symmetrical & binucleated Dorsal side: convex, ventral side: concave, w/ large adhesive disc for attachement 4 pairs of flagella PESANTE, BRITNEY C. 15  TOPIC IV: FLAGELLATES Divided by longitudinal binary fission produce cyst (encystation) and passed in Entire surface is covered w/ Variant- specific feces. surface proteins (VSPs) 7. These resistant cyst are the infective form and Pear shaped; kite shape; bilaterally symetrical can survive for months in warm climates. with rounded anterior and tapering posterior PATHOGENESIS The only known parasitic intestinal flagellate Incubation period: 10-36 days Parasite damages the microvilli by coating the intestinal epithelium and interferes in absorption of fats and other nutrients. Diarrhea, dehydration, abdominal cramps, anorexia, flatulence and tederness of epigastric area Steatorrhea increase in fat excretion in the stools due to malabsorption With sucking disc (ovoid, occupying around ¾ the flat central surface) With nucleus having a central karyosome “Gay Bowel Syndrome” sexually transmitted perianal and rectal disease, as well as traumas, seen amongst men who sex with men (MSM) “Beaver Fever” disease got its name after an outbreak in which hikers in Banff National Park became ill from drinking untreated stream water contaminated with Gardia DIAGNOSIS 1. Recognition of trophozoites or cysts in stained fecal smears is adequate for diagnosis 2. For benign infections, DUONEDENAL ASPIRATIONS may be necessary to demonstrate trophozoites 3. Entero-Test (String Test) one type of test used to detect the presence of parasites in the upper CYST part of the small intestine can also be Ovoid; 8-12 um long by 7-10 um wide performed Young cyst: 2 nuclei 4. Polymerase Chain Reaction (PCR) a Mature cyst: 4 nuclei (infective stage) laboratory technique used to amplify DNA Characterized by flagella retracted in sequences 5. Gold Standard: Direct fluorescent antibody AXONEMES assay (immunodiagnostic method relying of Surrounded by tough hyaline cyst wall secreted detection of serum antibodies from condensed cytoplasm TREATMENT LIFE CYCLE Flagyl (Metronidazole) 1. Human ingest Giardia lamblia cyst through o antiamoebic and anti-infective contaminated fluid or water. Pregnant women are advised not to take 2. Will travel to the esophagus down to the metronidazole during the 1st trimester of stomach and essentially combine to the pregnancy mucous layer of the small intestine in the duodenum. Paromomycin is an alternative and safer drug 3. In the small intestine, one cyst will become two trophozoite (excystation). PREVENTION AND CONTROL 4. Trophozoite will multiply through longitudinal 1. Proper disposal of human excreta binary fission.(Trophozoite can produce cyst). 2. Campers should be equipped with bottled 5. Trophozoite will attach to the villous surface of water the small intestine (suction disk), causing 3. Proper water treatment (chem therapy and abdominal pain, cramps and dysentery. filtration) 6. The trophozoite can actually move to the colon 4. Double strength satured iodine solution and bind to the mucosal surface their and PESANTE, BRITNEY C. 16  TOPIC IV: FLAGELLATES EDUCATIONAL VIDEO: GIARDIASIS- TRICHOMONADS GIARDIA LAMBLIA HUMAN TRICHOMONAS GIARDIASIS Trichomonas vaginalis – biggest Disease that is cause by protozoan flagellates: Trichomonas hominis Giardia intestinalis or Giardia lamblia Prominent in developing countries: Over- Trichomonas tenax – smallest crowding, unhygienic and poor water quality. Developing countries: prevalence is highest in Family Trichomonadidae children. Easily recognized for their anterior tuft of May cause by diarrhea like symptoms and flagella, a stout median rod axostyle and an abdominal pain. undulating membrane In fresh preparation, trichomonads, produce a HOW IT CAUSES AN INFECTION? characteristic jerky and twisting locomotion 1. Human ingest Giardia lamblia cyst through 10 um contaminated fluid or water. Have a tumbling motility 2. Will travel to the esophagus down to the Pear-shaped stomach and essentially combine to the Single nucleated mucous layer of the small intestine in the duodenum. Exists only in trophozoites stage 3. In the small intestine, one cyst will become two Found in intestinal or reproductive tracts of trophozoite (excystation). vertebrates and invertebrates 4. Trophozoite will multiply through longitudinal Species found in birds: Trichomonas gallinae binary fission.(Trophozoite can produce cyst). 5. Trophozoite will attach to the villous surface of Trichomonas tenax the small intestine (suction disk), causing abdominal pain, cramps and dysentery. Inhibits mouth 6. The trophozoite can actually move to the colon 7-8 um (ave: 6 um) and bind to the mucosal surface their and Smallest produce cyst (encystation) and passed in feces. Trichomonas hominis 7. These resistant cysts are the infective form and Inhibits intestines can survive for months in warm climates. Slightly larger than tenax SYMPTOMS Trichomonas vaginalis Abdominal Pain Nausea Inhibits genital tract Diarrhea 7-23 um (ave: 13 um) Rarely blood and mucus in stool Largest Chronic infection can be associated with VB12 malabsorption and lactose intolerance. STRUCTURE Flagella DIAGNOSIS Undulating axostyle Microscopic examination of cyst in the stool. Costa If negative (suspected)- string test (string is put Nucleus to the mouth going to GI tract then will take a sample in the mucus layer of the small Hydrogenosomes – membrane-bound structure intestine) then another microscopy. Cytostone TREATMENT Axoneme Metronidazole Number of flagella Length of undulating membranes Granules along the axostyle PESANTE, BRITNEY C. 17  TOPIC IV: FLAGELLATES TRICHOMONAS HOMINIS TRICHOMONAS VAGINALIS SIZE 7-13 um SIZE 7-23 um NUCLEUS Situated in the anterior NUCLEUS single end FLAGELLA 3-5 anterior, 1 FLAGELLA 5 anterior, 1 posterior posterior UNDULATING Full body length UNDULATING Extends about ½ of MEMBRANE MEMBRANE the organism Found in intestine Found in genitaltract 5 anterior + 1 posterior flagella Largest among the trichomonads Full body length undulating membrane 3-5 anterior and 1 posterior flagella Hydrogenosomes are found only along the Undulating membrane extends ½ of the body costs length Non-pathogenic Hydrosomes are constant along the costa and Fecal-oral route = mode of transmission theaxostyle Inhabits the cecal area of large intestine Prominent axostyle Rapid and jerky motility TRICHOMONAS TENAX SIZE 5-12 um PATHOGENESIS NUCLEUS single Trichomoniasis is associated with other FLAGELLA 4 anterior, 1 posterior sexual disease like Gonorrhea UNDULATING Extends 2/3 of the Degeneration and desquamation of vaginal MEMBRANE body length epithelium followed by leukocytic inflammation which is evident via a whitedischarge Found in mouth Intense itchiness and burning sensation while Smallest among the trichomonads urinating 4 anterior + 1 posterior flagella STRAWBERRY CERVIX Undulating membrane extends 2/3 of the body 2% of cases length Foul-smelling, frothy, creamy, liquid vaginal Hydrogenosomes are found only along the secretions, greenish, or yellow in or color costa but fewer compared to T. hominis Dysuria is also possible Non pathogenic Infected individuals are given Metronidazole Inhabits the human mouth, living in the tartar around the teeth and gums DIAGNOSIS Saline preparation – quickest and most Exposure results from droplets of the mouth, inexpensive way to diagnose trichomoniasis kissing, sharing of utensils Culture (2 to 5 days) – Gold Standard; o Diamond’s modified medium o Feinberg and Whittington medium Papanicolau-stained smear MANAGEMENT Vinegar douch o Relieves inflammation and congestion; restores normal pH of vagina o 30 ml vinegar in 1000 ml of water o Hanging drop – demonstrate motility o Media prep: Trussel and Johnson’s medium PESANTE, BRITNEY C. 18  TOPIC V: CILIATES TROPHOZOITE BALANTIDIUM COLI 50-100 um by 40-50 um ciliated protozoan, and is the only one that is Ovoid, known to be pathogenic to humans with narrowed anterior end and is shaped like a sac Balantidium = little bag/little bag CYTOSTOME (mouth) CYTOPYGE (anus) 2 nuclei – macro- & micronucleus o Macronucleus: bean-shaped; easily identified in stained specimens 2 contractile vacuoles COMMON NAMES Paramecium coli Leukophyra coli Holophora coli DISEASE Balantidiasis/Balantidial dysentery Balantidiosis Balanatidial disease GEOGRPAHICAL DISTRIBUTION Cosmopolitan B.COLI Hosts: pigs, wild boars, rats, primates (including humans), horses, cattle and guinea pigs Pigs (natural host) are the most significant hosts,though they show few if any symptoms. CYST Accidental Host: HUMANS Greenish – yellow if unstained Spherical covered with thick cell walls MORPHOLOGY 45-65 um indiameter The largest intestinal ciliated protozoan of man Colonize the LARGEINTESTINE Both cyst and trophozoites are identifiable by a large “sausage shaped” macronucleus Move by means of hairlike cytoplasmic extensions called “cilia” PESANTE, BRITNEY C. 19  TOPIC V: CILIATES LIFE CYCLE DIAGNOSIS DFS; Trophs and cysts TREATMENT Diiodoiun or Carbarsome are the drugs of choice Resembles the life cycle of Entamoeba histolytica. (ciliated stage or trophozoite stage of this parasite lives in lesion in the large intestine and it erodes the tissue by eating the cell). 1. Cysts ingested with fecally contaminated food or water.(reservoir host) 2. The cyst travels to small intestine:(Excystation) 1 cyst= 2 Trophozoites in small intestine. 3. Trophozoites resides in transverse colon and inhabits the lumen, mucosa and submucosa of the large intestine primarily the cecal colon and invade tissues of colon. 4. Parasite reproduction through binary fission/ sexual reproduction (conjugation). 5. Burrow into the tissue using cilia and ingesting the cells. 6. PATHOLOGY: crater-form ulcer in colon. (dysentery) 7. Trophozoite encyst in colon during intestinal transport or after evacuation of semi formed stool. 8. Cysts (infective stage) pass with feces. TRANSMISSION Infective stage: CYST o via hog’s feces ingested with raw salads or contaminated water PATHOLOGY: BALANTIDIASIS Much larger and sturdier, thus, produces a bigger opening in the intestinal mucosa as it enters the wall Penetration is accomplished more by its boring action than by lysis (hyaluronidase) Characteristic ulcer with a round base and wide neck Vary from fulminating, sometimes fatal dysentery or profuse diarrhea PESANTE, BRITNEY C. 20