Protozoa II: Ciliphora

Question 1

What are the characteristics of the phylum Ciliophora?

Answer 1

2 types of nuclei (macronucleus and micronucleus)
Ciliated body
Food ingested through cytostome
Reproduces by binary fission
Majority are free living

Question 2

What is the largest parasitic protozoan in humans?

Answer 2

Balantidium coli

Question 3

How many species are hosts of Balantidium coli?

Answer 3

50

Question 4

What are some of the hosts of Balantidium coli?

Answer 4

Pigs*, humans, other primates, horses, bovine, rodents

Question 5

What is the distribution of Balantidium coli?

Answer 5

Worldwide

Question 6

What is the location of Balantidium coli in the host?

Answer 6

Large intestine

Question 7

What kind of life cycle does Balantidium coli have?

Answer 7

Direct life cycle

Question 8

Describe the direct life cycle of Balantidium coli

Answer 8

Cysts in host feces
Cysts are ingested by host
Trophozoites exist in the small intestine
Trophozoites usually colonize the large intestine and undergo binary fission
Encystation in large intestine and cyst formation occurs
Cyst, trophozoites are excreted
Cysts are ingested
—Infective stage

Question 9

How long does it take for the life cycle of Balantidium coli to complete?

Answer 9

4-5 days

Question 10

What is the reproduction of Balantidium coli?

Answer 10

Asexual (transverse binary fission)

Question 11

What is the infective stage of Balantidium coli?

Answer 11

Cyst in feces

Question 12

What is the route of infection of Balantidium coli?

Answer 12

Fecal-oral

Question 13

Describe the Balantidium coli trophozoites

Answer 13

Horseshoe shaped macronucleus
Ciliated
Fresh fecal sample
Direct smear: looking for motile ciliated trophozoites

Question 14

Describe the Balantidium coli cyst

Answer 14

Shed in feces
Detection by flotation (zinc sulfate)
Large horseshoe shaped macronucleus

Question 15

What are the clinical signs of Balantidium coli in domestic/wild pigs?

Answer 15

Usually asymptomatic

Diarrhea, colitis

Question 16

What is the treatment of Balantidium coli?

Answer 16

Not usually treated in swine

Zoonotic potential

Question 17

How is Balantidium coli controlled?

Answer 17

Interrupt fecal-oral transmission

Question 18

What are the at risk populations for Balantidium coli?

Answer 18

Rural, institutionalized groups

Immunosuppressed

Question 19

What is the reservoir host of Balantidium coli?

Answer 19

Pigs

Question 20

What are the other potential routes of infection of Balantidium coli?

Answer 20

Watreborne or food contamination

Question 21

What is the largest parasitic protozoan in fish?

Answer 21

Ichthyopthirius multifiliis

Question 22

What is the parasitic fish stage of Ichthyophthirius multifiliis?

Answer 22

Motile ciliated trophont with a distinct horseshoe shaped macronucleus

Question 23

What does Ichthyophthirium multifiliis have outbreaks and high mortalities in?

Answer 23

Aquacultured fish species

Question 24

What stage of the Ichthyophthirius multifiliis life cycle is treatable with chemotherapeutics?

Answer 24

Theront

Question 25

Describe Ichthyophthiriys multifiliis trophonts

Answer 25

Parasitic fish stage
Sites of infection: gills, fins, and skin
Protected from chemical treatments
Mature on fish and drop off into the water
Encyst

Question 26

Describe Ichthyophthirius multifiliis tomonts

Answer 26

Protected and encysted stage in water

Binary fission within the tomont produces tomites

Question 27

Describe Ichthyophthirius multifiliis tomites

Answer 27

Furter develop into theronts

Release of theronts

Question 28

Describe Ichthyophthirius multifiliis theronts

Answer 28

Motile, ciliated stage
Theronts emerge from the tomont into the water column
Encounter a fish host
Targeted stage
Penetrate epithelium of fish and develop into trophonts
At normal ambient temperatures, 24-27 deg. C, they must contact a fish host within 48-72 hours

Question 29

What is the completion of the Ichthyophthirius multifiliis life cycle dependent on?

Answer 29

Temperature (lower temperatures)

Question 30

What is the optimal temperature range for the Ichthyophthirius multifiliis life cycle?

Answer 30

24-25 deg. C

Question 31

What are the signs of Ichthyophthirius multifiliis?

Answer 31

Small white nodules on skin/gills/fins
Epithelial erosion, sloughing of epidermis, focal necrosis, ulcerations, excess mucus production
Gills: oxygen exchange compromised
Flashing (abnormal swimming behavior)
Lethargy, anorexia
Mortalities

Question 32

What are the Ichthyophthirius multifiliis diagnostic methods?

Answer 32

Live/freshly dead fish
Mucus from suspect area
Direct smear with dechlorinated water
Looking for trophont stage
Wet mount
Histology (H and E)

Question 33

What is the treatment of Ichthyophthirius multifiliis for home aquaria/ornamental fish?

Answer 33

Treat for at least a week
Gradually increase temperature to suboptimal temperature
Multiple treatments may be necessary

Question 34

What are the over-the-counter treatments available for Ichthyophthirius multifiliis?

Answer 34

Malachite green/formalin (Quick Cure)
Copper sulfate
Potassium permanganate
Formalin
Methylene blue

Question 35

What is the treatment of Ichthyophthirius multigiliis for aquaculture (food fish)?

Answer 35

Copper sulfate
Potassium permanganate
Formalin
Salt

Question 36

What is the prevention and control of Ichthyophthirius multifiliis for home aquaria?

Answer 36

Quarantine fish
Don’t add travel water to tank display
Keep temperatures stable and reduce stress
Purchase plants from tanks with no fish
Disinfect all items from other aquaria
Do not purchase from tanks with sick or dead/dying fish

Question 37

What is the prevention and control of Ichthyophthirius multifiliis for aquaculture?

Answer 37

Prevent wild fish from entering the pond
Ground water v. surface water
Allow pond to remain unstocked for 3-4 days after filling
Disinfect equipment
Avoid cross-contamination

Question 38

What is Cryptocaryon irritans similar to?

Answer 38

Ichthyophthirius multifiliis