Cilliates : Balantidium coli

Ciliates

Protozoans parasite

Cilia

Hair-like cytoplasmic extensions

Balantidium coli

Largest protozoan parasite affecting humans and the only ciliate known to cause disease in humans.

Ovoid to sac-shaped

Shape of trophozoite

Balantidium

little bag

Neobalantidium coli or Balantioides coli

Other names

Paramecium coli

Identified as ____________ by Malmsten in 1857.

Balantidiasis , balantidiosis, or balantidial desentery

Its Zoonotic disease

Pigs

Normal host

Rotary, boring motility

Motility

Covered with cilia arranged in a longitudinal pattern extending from the oral to the caudal region

Locomotion (trophozoite)

Cytostome

Oral apparatus; acquire food

Cytopyge

Waste excretion

Macronucleus and Micronucleus

2 nuclei under trophozoite

osmoregulatory organelles

Function of the 2 vacuoles

Macronucleus

Bean-shaped or kidney bean shaped; can easily be identified in stained preparations; often appear as a hyaline mask especially in unstained preparations

Micronucleus

Small dot-like nucleus; round and lies in the concavity of the macronucleus; often not readily visible even in stained preparations

Cytoplasm

May contain food vacuoles and ingested microbes

Mucocysts

Extrusive organelles; located beneath the cell membrane; might have a function in the adhesion of the parasitic ciliates; may contribute to the parasite virulence (no definitive study to prove)

Cyst

Spherical or subspherical to slightly ovoid in shape

Cyst

Are covered with thick cell walls and they are referred to as “double walled cyst”

Mature cyst

This cyst tend to lose their cilia

Cyst

Only macronucleus is seen

Cyst

Infective stage

Trophozoite and cyst stage

Diagnostic stage

Ingestion of food and/or water contaminated with Balantidium coli cysts

Mode of transmission

4-5 days

Incubation period

Small intestine

Where excystation occurs

Asexual

asymmetric binary fission (transverse binary fission

conjugation

conjugation

Lumen

Where encystation occurs

Binary fission

A method of asexual reproduction in which a single parasite divides either longitudinally or transversely into 2 or more equal number of parasite

Transverse binary fission

Mode of replication for ciliates

Longitudinal binary fission

Mode of replication for flagellates

Rounded base with wide neck ulcers

Characteristic ulcer , caused by hyaluronidase

Hyaluronidase

Lytic enzyme secreted by the trophozoite

• Intestinal perforation

• Acute appendicitis

Complications of balantidiasis

Co-infection with other organisms

may also contribute to the severity of the Balantidium coli infection

Intrinsic host factors that contribute to host susceptibility and severity of B. coli infection

• Nutritional status

• Intestinal bacterial flora

• Achlorhydria

• Alcoholisms

• Presence of chronic disease

Nutritional status

Poor nutrition can weaken the immune system

Can make the body more susceptible to infections

Intestinal bacterial flora

The balance of bacteria in the intestines can influence how easily B.coli can infect the host

An imbalance in the normal flora may make it easier for the parasite to thrive

Achlorhydria

Refers to a lack of stomach acid

Normally helps kill harmful microorganisms

Without sufficient stomach acid the body is now vulnerable to infections including B.coli

Alcoholisms

Can weaken the immune system

Also alters gut flora and may damage the gastrointestinal tract

Presence of chronic disease

Can impair immune function making it easier for infections like Balantidiasis to develop

• Asymptomatic carriers

• Fulminant Balantidiasis / Balantidial Desentery

• Chronic Balantidiasis

Clinical Manifestations

Asymptomatic carriers

Do not present with diarrhea or dysentery

May serve as parasite reservoir in the community

Fulminant Balantidiasis / Balantidial Desentery

Diarrhea with bloody and mucoid stools, sometimes may be indistinguishable from amebic dysentery

Acute cases may have 6 to 15 episodes of diarrhea per day accompanied by abdominal pain, nausea, and vomiting

Often associated with immunocompromised and malnourished states

Chronic Balantidiasis

Diarrhea may alternate with constipation

May be accompanied by nonspecific symptoms such as abdominal pain or cramping, anemia, and cachexia

• Direct Examination

• Concentration techniques

• Sigmoidoscopy

Laboratory Diagnosis

Bronchoalveolar washings

Diagnosis in cases of pulmonary infection

Lugol’s iodine

sometimes used for staining, but may obscure internal morphological features

• Tetracycline

• Metronidazole

TREATMENT

• Iodoquinol

• Doxycycline

• Nitazoxanide

Other alternative treatments