This document discusses two genera of ciliates - Balantidium and Buxtonella. Balantidium coli infects the large intestines of humans, pigs, rats and monkeys. It causes balantidial dysentery through tissue invasion and damage. Symptoms include diarrhea and dysentery. Buxtonella sulcata infects the large intestines of cattle and buffaloes but may not cause pathology. It can be differentiated from B. coli by its trophozoite morphology which has a prominent curved groove.

1. Phylum – Ciliophora

2.  Organisms with cilia as locomotor organelles.
 Highly organized forms with one large macronucleus which conducts
the cytoplasmic activities and a small vesicular micronucleus for
reproduction function.
 They are heterokaryoitc (2 kinds of nuclei).
 Asexual reproduction is by transverse binary fission and sexual
reproduction by conjugation.
 Ciliates are free living, commensals or symbionts.
 Rumen ciliates are useful in digestion.
 Caecal and colon ciliates are commensals in equines.
Introduction

3. Genus – Balantidium
 B.coli occurs in the large intestine of man, pig, rats and monkeys.
Rodents can be experimentally infected. Caecum and colon are
preferred habitats. Large sized trophozoites are 50-60m long and
are oval or pear shaped. Cilia are arranges in longitudinal rows,
persistome is subterminal and located at the narrower end which
leads to mouth or cytostome. The post end leads to the excretory
opening or cytopyge.
 The macronucleus is kidney shaped and micronucleus is small
and round and lies in the notch of the macronucleus. Food and
contractile vacuoles are found in the cytoplasm and trophozoites
are actively motile.
 Cysts are ovoid or round 40-60m. The macronucleus is very
distinct in cysts which have 2 cell membranes and are resistant in
nature.

4. Life cycle
Infection is faeco oral through ingestion of cysts but
trophozoites are also sufficiently resistant to pass
through the stomach and reach the small intestine.
The organism reproduces by transverse binary fission
in the large intestine of the host.
Conjugation has been studied in culture.

5.  Pathogenecity: In pigs B. coli are commensales in the
intestinal tract and cause disease under predisposing
conditions.
 Trophozoits penetrate the intestinal mucosa by secreting a
proteolytic enzyme called hyaluronidase.
 They ingest bacteria in the intestine, tissue debris, RBCs,
WBCs etc.
 Due to penetration they cause superficial to deep ulcerations
in the mucosa leading to mild to severe haemorrhagic
enteritis known as balantidial dysentery.
 The muscular layer may also be invaded and lesions similar to
those of amoebiosis are produced, but they do not spread,
are smaller in size and other organisms are not invaded.
 Infections may be associated with helminths and or bacteria.

6. Symptoms as of amoebiosis. In man B. coli is
invasion, infection is acquired from pigs and it
damages the large intestine leading to diarrhoea,
dysentery and ulceration of tissue. Sometimes
organisms may be found in extraintestinal sites.
Higher primates (nonhuman) have their own B. coli.
Sometimes dog may get infected.
Diagnosis: Faecal examination, direct examination,
floatation NaCl or ZnSO4.
Treatment: Tetracycline, carbarsone, metromidazole
acute enteritis characterized by eatery diarrhoea and
lethargy in gorillas and good response was seen with
I/M injections of dehydroemetine HCl.

7. Buxtonella sulcata
 It occurs in the large intestine of cattle and buffaloes. Trophozoites
are ovoid, uniformly ciliated with a prominent curved groove
bordered by 2 ridges. Cytostome is near anterior end. Measure 60-
138 x 46-100m. Cysts are thin walled ovoid and spherical 47-
76m. Cyst encloses a coarsely granular cytoplasm which is pale
yellow brown.
 It is easy to differentiate trophozoites of Buxtonella and B. coli but
cysts are morphologically very similar. They may not cause any
pathogenecity at all. Heavy infections have been found to cause
enteritis.
 Treatment: Furazolidone

8. THANKS