Microbiology Chapter 5: Eukaryotic Cells

Endosymbiotic Theory

Endosymbiotic Theory

evolution of eukaryotic organisms from prokaryotic organisms by symbiosis; organelles originated form prokaryotic cells trapped inside them

Rough endoplasmic reticulum

synthesis of proteins

Smooth endoplasmic reticulum

synthesis and storage of lipids

Molds

MULTIcellular

Yeast

UNIcellular

Superficial Fungal Infections

on surface of body, not invasive

Systematic Fungal Infections

deeply invasive; can invade lungs and other tissues

Trichophyton, Microsporum, and Epidermophyton

fungi that occur naturally in the soil and on animals, can cause infections of the epidermis (dermatophytes)

Ex. tinea corporis (ringworm)

Candida albicans

yeas that occurs naturally on the body, can cause opportunistic infections of the epidermis

Ex. candidiasis (thrush) - common fungal infection of mucus membranes, skin, and nails

Cryptococcus neoformans

found in soil, decaying wood, tree hollows, or bird droppings and acquired through inhalation of spores; can cause no infection, latent infection, or systemic disease in immunocompromised hosts

Mastigophorans defintion

flagellated and single nucleus pathogens, most form cyst and are free-living

Examples of Matigophoran Pathogens

Trypanosoma - causes African Sleeping Disease and spread by insect vectors

Giardia - causes giardiasis and spread by water contaminated with feces

Trichomonas - a parasite of reproductive tract, causes trichomoniasis (STD) and spread by sexual contact

Amoebas (Sarcodina)

major locomotors are pseudopods, asexual repoduction by fission, mostly uninucleate, free-living and not infectious

Examples of Amoeba Pathogens

Entamoeba histolytica - causes bloddy diarrhea

Ciliphorans

trophozoites are motile by cilia, some have cilia in tufts for feeding and attachment, most develop cysts

Examples of Ciliphoran Pathogens

Balantidium coli - cause intestinal infection called balantidiasis which causes diarrhea and abdominal pain

Apicomplexans (Sporozoa)

motility is absent in most cells, complex life cycles with asexual and sexual stages

Examples of Apicomplexan Pathogens

Plasmodium - cause Malaria and infected by mosquitoes

Toxoplasma gondii - causes an acute infection called toxplasmosis and acquired from cats

Cryptosporidium - causes cryptosporidiosis transmitted by contaminated water causing diarrhea

Flatworms

flat, no definite body cavity, digestive tract a blind pouch, simple excretory and nervous systems

Ex. Cestodes (tapeworms), trematodes (flukes with sucking mouthparts)

Roundworms

also called nematodes, round, complete digestive tract, spines and hooks on mouth, excretory and nervous systems poorly developed

Ex. Enterobius vermicularis (Pinworm)

Medical Importance of Helminth Infections

• distributed worldwide

• affections billions of humans

• acquired through…

  • ingestion of larvae or eggs in food

  • soil or water

  • insect vectors