Microbes Flashcards
General classes of organisms that can cause infectious disease
Bacteria Fungi (eukaryote) Protozoa (Eukaryote) Arthropods (eukaryote) Helminths (eukaryote) Viruses Prions
Names of unicellular and multicellular fungi
Yeast; Hyphae (mold)
Examples of parasites and their class
Scabies mite (arthropod)
Malaria (protozoan)
Giardia (protozoan)
Trichuriasis trichuria (AKA whipworm, helminth)
Disease associated with prions
spongiform encephalopathies including:
Kuru
Creutzfeldt-Jacob Disease (CJD)
Mad Cow Disease
Relative size of medically important organisms
virus < bacteria < protozoa < helminths
Serogroup, serotype, biotype are all synonymous with…
strain
Classification of bacteria is according to…
gram + or -, shape, respiration, reproduction (spores?)
Classification of viruses is according to…
nucleic acid type and sense, presence of envelope, symmetry
Pathogenicity vs.Virulence
Pathogenicity: the quality of being pathogenic
Virulence: the intensity of the pathogenicity
Contrast colonization and infection
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Medical examples of mutualism, commensalism and parasitism
Mutualism: gut bacteria that make vitamin K for us
Commensalism: gut bacteria that get a free place to live
Parasitism: worms
Strict pathogens vs. opportunistic pathogens
Strict pathogens always cause disease, opportunistic pathogens are not normally pathogenic, but can become so in abnormal situations (e.g. in immunocompromised individuals)
Development of normal flora
skin, oropharynx and GI are colonized during passage through birth canal and first few days of life (including breastmilk)
Influences on normal flora
oxygen levels
antibacterial substances (e..g lysozyme)
Other flora
Benefits of normal flora
Food metabolism
Produce vitamins (B and K)
Normal immune system development
Exclusion of pathogenic microbes via competition of secretiong of toxic metabolites
Examples of bacterial metabolites that alter their environment
Lactobacilli –> acidic env. in vagina
Bifidobacterium–> decrese gastric pH in breastfed infants
Bacteriocins (antibacterial factors)
Probiotics vs. Prebiotics
Live bacteria (e..g bifidobacterium, lactobacillus) (…can also be fecal transplant)
Non- digestable food ingredients that stimulate the growth of a select group of microbes (e.g soluble and dietary fiber, inulin)
Examples of immunocompromised individuals
Bone marrow transplant pts are on prophylactic antibiotics
HIV/AIDS