Parasitic taxonomy

1. Balwant Singh
Babasaheb Bhimrao Ambedkar University Lucknow
Taxonomy of Parasites

2. What is parasite ?
 An organism that lives in a symbiotic
relationship with a phylogenetically unrelated
organism over a prolonged period of time.
 An organism which depends on other organism
for its food, shelter and protection is called a
parasite.
 A Parasite lives in or on its host.
 Relationship lasts the lifetime of the host.

3. Division of Parasites
 The Animal Kingdome is divided into two sub-
kingdoms of parasites-
1) Protozoa :- 45,000 unicellular species, each
defined in the phylum according to organelles,
locomotion, life cycle and type of reproduction.
2) Metazoa :- Multicellular organisms.

4. Subkingdom-Protozoa
 Subkingdom Protozoa is categorised in four
phylum's-
1) Sarcomastigophora Subphylum =
Sarcodina
Subphylum =
Mastigophora
2) Apicomplexa
3) Ciliophora
Movement with pseudopodia e.g. -
Entamoeba
Movement with flagella e.g.- Giardia,
Trichomonas
Apical complex, No locomotor apparatus; Sexual reproduction e.g.-
Plasmodium
Movement with cilia e.g.-
Balantidium
e.g.- Enterocytozoan
(microsporidium)

5. Subkingdom-Metazoa
 Subkingdom Metazoa is categorised into three phylum's-
1) Nematoda
2) Platyhelminthes Class = Cestoidea
Class = Trematoda
Round worms, Round in cross section; Separate
sexes; Complete digestive tract; 500,000 species only
a few parasitic to man e.g.- Ancylostoma (hookworm)
Tapeworms; Segmented bodies each segment
containing complete set of male and female
reproductive organs; No alimentary tract, nutrition by
absorption through body wall e.g.- Taenia (tapeworm)
Flukes; Leaf shaped Unsegmented body,
Complex life cycle e.g.- Clonorchis (liver
fluke)
Flat worms; Incomplete or
absent digestive tract; No
body cavity; Mostly
hermaphroditic

6. Subkingdom-Metazoa
 3) Arthropoda
Multicellular, Male female septet, Always ectoparasite,
Digestive system complete e.g.- Bed bugs, Mites, Teaks

7. Intestinal Protozoa
 Pathogenesis: in small intestine : Giardia,
Microsporidia, Cryptosporidia, Cyclospora
in large intestine : Entamoeba histolytica
 Epidemiology: Zoonoses
Carrier states
Fecal-Oral transmission
 Clinical features: Acute
Chronic
Asymptomatic carrier states
Opportunism in the
immunocompromised

8. Intestinal Protozoa
 Diagnosis: Stool examination
Stains
Transport preservatives
 Treatment: Metronidazole
Diodoquine
Trimethoprim/sulfa
 Problems: Drug resistance
Pathogenesis
Laboratory identification

9. List of Intestinal Parasites
Sarcodina: Entamoeba histolytica**
Entamoeba dispar
Iodomoeba butschlii
Endolimax nana
Entamoeba coli
Entamoeba hartmani
Dientamoeba fragilis**
Apicomplexa: Cryptosporidium parvum.**
Isospora belli **
Cyclospora cayetanensis**
(**=pathogenic)

10. Cont…
Mastigophora: Giardia lamblia**
Trichomomas hominis
Chilomastix mesnili
Ciliophora: Balantidium coli**
Microsporidia: Enterocytozoon bienusi**
(**=pathogenic)

11.  Vaginal protozoa
Trichomonas vaginalis
 This protozoan parasite belong to subphylum
Mastigophora.
 A unicellular (av. 13 µm) flagellate which moves with
3-4 terminal flagella and a flagella in an undulating.
 No cystic form
 multiples by binary fision
 lives in close association with vaginal, urethral and
prostatic tissue

12.  Vaginal protozoa
 Pathophysiology:
Causes degeneration and desquamation of local tissues
Mechanism unclear
 Epidemiology:
Found in 3-5% of female population of N.A.
Increased in STD clinics (50%)
Prostitutes 50-75%
Only in humans; no animal reservoir
Sexual transmission, but also on fomites
Can persist for 2 years in host
 Clinical: Asymptomatic
Symptomatic
Vast majority
Vaginitis, prostatitis, urethritis

13.  Vaginal protozoa
 Diagnosis:
“Wet mount" of vaginal secretions, urine
sediment or prostatic massage; characteristic fast (darting)
movement
 Treatment: Metronidazole

14. Some other Intestinal
Protozoan's
 Pathogenic
1) Balantidium coli (large intestine, Ciliata)
2) Isospora belli (small intestine, Apicomplexa)
3) Dientamoeba fragilis (small intestine,
Mastigophora)
4) Enterocytozoon bienusi (small intestine,
Microspora)
 Nonpathogenic
1) Entamoeba dispar 5) Blastocystis hominis
2) Entamoeba coli 6) Trichomonas hominis
3) Endolimax nana 7) Enteromonas hominis
4) Iodomoeba butschlii

15. Thank You
Mr. Balwant Singh
M.Sc.(Applied Animal Science)
Department of Applied Animal Science
Babasaheb Bhimrao Ambedkar
University Lucknow-226025 INDIA