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)

Protozoa – life cycle

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

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

Groups based on locomotion & reproduction ______________– flagellates ______________– amebas ______________– ciliates ______________–motility not well developed but some move by gliding/flexing

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

Figure 5.28 7 7

Termite flagellates Mutualistic symbiosis Digests wood for insect Mastigophora Termite flagellates Mutualistic symbiosis Digests wood for insect ______________ (many flagella!) Trichonympha

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

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.

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

Trypanosoma species Mastigophora Transmitted by insects – Africa (tsetse flies, African Sleeping Sickness); South America (kissing bugs – Chagas’ disease) Lives extracellularly (African) and intracellularly (SA )

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

Sarcodina pseudopods 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

Figure 5.29 Sarcodina General structure 16 16

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

Sarcodina

Geographic Distribution: Worldwide, with higher incidence of amebiasis in developing countries.  In industrialized countries, risk groups include male homosexuals, travelers and recent immigrants, and institutionalized populations. WHY????

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

Basic structure of ciliates Ciliophora

ciliophora Balantidium coli cyst trophozoites

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)

General structure of Apicomplexa

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

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

Cryptosporidium spp. Modified acid-fast stain of oocysts in fecal smear

31 31

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