http://www.umanitoba.ca/science/zoology/faculty/dick/z346/balanhome.html Balantidiosis is acquired by humans via the fecal-oral route from the normal host, the pig, where it is asymptomatic. divide by transverse binary fission.
In areas where pigs are the main domestic animal, the prevalence of human infection can be high. Pig farmers, butchers or people working in slaughterhouses are particularly susceptible to infection. Human infection is fairly rare in temperate areas, although once the infection is established, it can spread to others, particularly where poor environmental sanitation and personal hygiene are found. The organism is cosmopolitan and can be found wherever pigs are found. Disease appears to be a problem mostly of developing countries, where water sources may be contaminated with porcine or human feces. B. coli can become an opportunistic parasite in immunosuppressed hosts living in urban environments, where pigs are not a factor in infection.
Trophozoite is the disease-producing stage, while the cyst is the infective stage. Both cysts and trophozoites pass in the feces, but only the environmentally-resistant cyst can survive outside the body and contaminate food and water. bean-shaped macronucleus. The mouth (oral apparatus) is located at the tapering anterior end, and the cytopyge (anus) is at the rounded posterior end
The cyst of Balantidium is the transmissive stage of the organism. Because of its thickened wall, it is protected from desiccation and other environmental stress. It survives best in humid surroundings protected from direct sunlight. The trophic ciliate is reportedly unable to survive passage through the stomach because of the low pH of gastric fluid. Cysts, however, were not produced in cultures of balantidia (32, 80), nor are they produced in cases of acute dysentery.
When the cyst is eaten, it “hatches” (excysts) in the host’s intestine, releasing the motile form that begins to feed on cell fragments, starch grains and other organic matter. Balantidium has a simple life cycle, as follows: dormant cyst to trophozoite and trophozoite to cyst. Transmission is direct, from a contaminated water or food supply to humans (Fig. 1). No intermediate host, as occurs with many other parasitic species, is needed.
Balantidium coli is an intestinal protozoan parasite. The life cycle of this parasite is very similar to that of Entamoeba histolytica . Unlike Entamoeba histolytica , the Balantidium coli trophozoites can encyst after being passed in the faeces. Balantidium coli can infect many species of mammal and human infections are most likely acquired by infection from a reservoir host. Death is an infrequent consequence of balantidiosis, but in developing countries with undernourished and overparasitized populations, it can make the difference between a healthy life and chronic debilitation.
Sexual reproduction as conjugation has been reported for Balantidium , but information is lacking about details of nuclear events.
The cyst of Balantidium is the transmissive stage of the organism. Because of its thickened wall, it is protected from desiccation and other environmental stress (Fig. 4). It survives best in humid surroundings protected from direct sunlight. The trophic ciliate is reportedly unable to survive passage through the stomach because of the low pH of gastric fluid, but Balantidium trophozoites inoculated into the stomach of guinea pigs have been found in the colon (56). The process of encystment begins in the colon and rectum of the host, and cysts are generally found in formed feces (56). Cysts, however, were not produced in cultures of balantidia (32, 80), nor are they produced in cases of acute dysentery.
Lab 13 balantidiasis
University of Sulaimani School of Science Department of Biology Practical Parasitology 2 nd stage Lab 13: Balantidiasis Ciliates: Balantidium coli
Ciliates: Balantidium coli <ul><li>Objectives: Students should be able to: </li></ul><ul><li>Describe trophozoite and cyst stages of Balantidium coli. </li></ul><ul><li>Explain methods of transmition and diagnosis of Balantidium coli. </li></ul>
Ciliophora (Ciliates) <ul><li>Feed on particulate food, small bacteria; other feed on large organisms. </li></ul><ul><li>Possess simple cilia during some part of their life cycle. </li></ul><ul><li>Most species have 2 kinds of nuclei: macronuclei and micronuclei. </li></ul><ul><li>Most ciliates are free-living. A few groups are commensals or parasitic. </li></ul>
<ul><li>Balantidium is the only ciliated protozoan known that is pathogenic in humans </li></ul><ul><li>and the largest protozoan infecting human. </li></ul><ul><li>Primarily a zoonotic intestinal parasite (pigs). </li></ul>cyst Balantidium coli
Final host : Human. Reservoir host : pigs (Zoonotic). Habitat : cecum and colon. Transmission : faecal-oral route and pigs appear to be the source of most human cases. G.D. Cosmopolitan and can be found wherever pigs are found Disease : Balantidiasis or balantidial dysentry Pig farmer. Balantidium coli
<ul><li>Trophozoites are oval in shape with 50-100 µm long by 40-70 µm wide. </li></ul><ul><li>An anterior funnel shaped cytosome is usually visible. </li></ul><ul><li>At the posterior end is an excretory opening called cytopyge. </li></ul><ul><li>Short cilia cover the cell surface. </li></ul><ul><li>Internally, a horse-shoe or sausage-shaped or kidney-shaped macronucleus is prominent; the adjacent round micronucleus is not. </li></ul>Balantidium coli: T rophozoite
<ul><li>Cysts are usually spherical or slightly ovoid and have a diameter of 45-65 µm </li></ul><ul><li>There is a cyst wall and the cilia are absent </li></ul><ul><li>As in the trophozoite, the macronucleus is prominent , but the micronucleus may not be. </li></ul>CYST - formed as feces dehydrate in the colon or rectum Balantidium coli: Cyst
Balantidium coli Life Cycle Ingestion of Cyst : infective stage
<ul><li>Active – </li></ul><ul><li>Trophozoite Stage. </li></ul>Cyst Phase. Encystation Excystation occurs in the small intestine The trophozoite inhabits the cecum and colon of humans.
Trophozoites are tissue invaders. They secrete proteolytic enzymes ( Hyaluronidase) which digest the epithelium of the large intestine. Ulceration results in bleeding and secondary bacterial infection. Perforation of the large intestine has occurred in some fatal cases. Balantidium coli: Pathology
1. Examination of stool samples, looking for trophozoites and cysts, which are readily identified because of their large size. Cyst Trophozoite Laboratory diagnosis
2. Biopsy of the colon: Numerous trophozoites in intestinal tissue.
References <ul><li>Schuster, FL. and Ramirez-Avila, L. Current World Status of Balantidium coli. (2008). Clin. Mic. Rev. 21(4): 626–638. </li></ul><ul><li>Schmidt GD, & Roberts LS. (2005). Foundations of Parasitology. 7th ed. McGraw Hill. Boston. </li></ul><ul><li>http://www.cdfound.to.it/html/bal1.htm </li></ul><ul><li>http://www.dpd.cdc.gov/dpdx/HTML/Balantidiasis.ht </li></ul><ul><li>http://www.stanford.edu/group/parasites/ParaSites2006/ </li></ul>http://www.tntech.edu/wrc/119.htm 6.http://parasitewonders.blogspot.com/2009_10_0 _archive.htm 7.http://pathmicro.med.sc.edu/parasitology/intest-protozoa.htm 8.http://www.umanitoba.ca/science/zoology/faculty/dick/z346/balanhome.html 9.http://www.ufrgs.br/parasito/dinamica/parasitos/protozoa/ciliophora/balantidium/balantidium.html 10.http://www.kstate.edu/parasitology/625tutorials/Ciliates.html 11.http://www.stanford.edu/group/parasites/ParaSites2003/Balantidium/Animal_Reservoir.htm
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