Protozoa

1
Protozoa

• ______________ animal-like protists
• 65,000 species
• most are ______________ , colonies are rare
• vary in shape
• lack a cell wall chloroplasts
• Some have a 2-stage life cycle
• ______________ - motile feeding stage
• ______________ a dormant resistant stage
• Many free-living species (have contractile
  vacuole)

2
Protozoa life cycle
3
Protozoa nutrition

• most are free-living in a moist habitat all are
  ______________
• feed by engulfing other microbes organic matter
  or absorbing through membrane
• Reproduction
• asexual and/or sexual

4
Locomotion

• most have locomotor structures
• flagella, cilia, or pseudopods
• Some have both flagella and pseudopods
• Some glide or flex

5
Groups based on locomotion reproduction

• ______________ flagellates
• ______________ amebas
• ______________ ciliates
• ______________motility not well developed but
  some move by gliding/flexing

6
Mastigophora flagellates

• Move by flagella, some also have pseudopods
• Usually single nucleus, some have multiple
• Reproduce asexually (mitosis, longitudinal
  fission) and some sexually (syngamy)
• Most are free-living, cyst-formers
• Some ___________lack certain organelles
• Many parasitic members

7
Figure 5.28
7
8
Termite flagellates
Mastigophora

• Mutualistic symbiosis
• Digests wood for insect
• ______________
• (many flagella!)

Trichonympha
9
Giardia lamblia
Mastigophora

• Intestinal parasite (______________)
• Characteristic teardrop shape
• 2 nuclei and sucking discs
• Multiple flagella and internal filaments
• Spread ______________ ______________
• Causes mucus-filled, flatulent ______________

trophozoites
cysts
10
(No Transcript)
11
Trichomonas vaginalis
Mastigophora

• ______________
• Has axostyle, undulating membrane and free
  flagella
• Parasite of the reproductive tract
• Spread ___________ (trophozoite)
• Frothy, green, purulent discharge

Men can be asymptomatic carriers.
12
Leishmania
Mastigophora

• Transmitted by insects (sandflies) Infects blood
  and organs of mammalian host
• Causes a variety of diseases, dependent on
  species
• Can live ______________

13
Trypanosoma species
Mastigophora

• Transmitted by insects Africa (tsetse flies,
  African Sleeping Sickness) South America
  (kissing bugs Chagas disease)
• Lives extracellularly (African) and
  intracellularly (SA )

14
Sarcodina amebas

• Locomotion ______________ , some have
  flagellated states
• Asexual reproduction fission
• Some amoebas have a hard shell made of minerals
  radiolarians, foraminiferans
• Most are free living

15
pseudopods
Sarcodina

• Can be lobular, blunt, branched, filamentous
  (long and pointed)
• Cytoplasm flows in pseudopod (ectoplasm)
• Used for feeding, protection and movement
• Results in constantly changing cell shape

16
Sarcodina
Figure 5.29
General structure
16
17
Entamoeba histolytica
Sarcodina

• Causes ______________ - bloody diarrhea
• Can invade extra-intestinal sites (ulcer ?
  systemic)
• ______________ found in fresh feces, host
  intestine
• Old infection or feces ______________ stage
• ______________ transmission

18
Sarcodina
19
Geographic DistributionWorldwide, with higher
incidence of amebiasis in developing countries. 
In industrialized countries, risk groups include
male homosexuals, travelers and recent
immigrants, and institutionalized populations.
WHY????
20
Ciliophora ciliates

• Use cilia for movement or feeding
• Can have more than one nucleus (macronucleus,
  micronucleus)
• Feed through a mouth like structure (oral
  groove, ______________ )
• Some reproduce sexually via conjugation and
  exchange micronuclei

21
Basic structure of ciliates
Ciliophora
22
Balantidium coli
ciliophora
cyst
trophozoites
23
Apicomplexa

• all are ______________
• Trophozoites move by gliding or flexion (see
  movie) or are non-motile
• Complex life cycles produce infective stage
  called ______________
• produce unique reproductive structures (sexual
  and asexual reproduction)

24
General structure of Apicomplexa
Apicomplexa
25
Malaria
Apicomplexa

• Caused by ______________ species
• Transmitted by mosquitoes
• Kills ______________ , infects 100-300 M
• Intracellular and extracellular stages
• ______________

26
Toxoplasmosis
Apicomplexa

• Toxoplasma gondii
• Acquired from ________
• Causes multiple symptoms pregnant
  women_______________
• ____________
• Re-emerging disease due to AIDS
• Intra and extracellular stages

27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
Cryptosporidium spp.
Modified acid-fast stain of oocysts in fecal smear
31
31
32
Protozoan ID and culture

• Morphology (cilia, flagella, etc. size, shape, )
• Location in body (such as presence of cyst or
  troph in feces)
• Number of nuclei
• May be cultured for additional ID
• Can be cultured in media or with cell/animal
  model