Microbiology Lec Exam 1

microbial ecology

microbes and the enviroment

bioremediation

microbes to clean up pollutants

food microbiology

microbes and food

applies/industrial microbiology

microbes to produce enzymes, vitamins, pharmaceuticals, etc.

medical microbiology

microbes & disease

normal flora

microbes found in/on body that don’t usually cause disease

resident flora

colonize on body

transient flora

on body for short period of time; don’t colonize

microbiome

all microbes residing on human body — varies

intestinal microbes

aid with digestion and vitamin synthesis

epidemiology

science of when/where diseases occur and how they spread

etiological agent

cause of disease

pathogen

disease-causing microorganism

host

organism that harbors the pathogen

reservoir

continual source of pathogen

zoonosis

disease transmitted from animal to human

pathogenesis

manner in which disease develops

direct contact transmission (person-to-person transmission)

direct transmission by physical contact

indirect contact transmission

spread by nonliving object

fomite

nonliving object involved in spread of infection

droplet transmission

spread by droplets that travel short distances

vehicle transmission

transmission of etiological agent by a vehicle

airborne transmission

spread via water droplet nuclei or other small particles

dry, smaller than respiratory droplets, can travel greater than 1 m

waterborne transmission

spread via water

foodborne transmission

spread via food

fecal-oral transmission

pathogen shed in feces —> contaminate food/water —> ingested

vector

animal that carries pathogen from one host to another

vector transmission

spread by vector

Carl Linneaus

father of binomial nomenclature and taxonomy

scientific nomenclature

each organism gets 2 names: Genus species

prokaryotes

no nucleus, no membrane bound organelles, unicellular

eukaryotes

nucleus, membrane-bound organelles, unicellular or multicellular

bacteria

prokaryotes, unicellular, no nucleus (genetic material in nucleoid), cell wall (peptidoglycan)

Legionella pneumophila

gram-negative rod, lives in freshwater, causes Legionnaires’ Disease, airborne transmission

Legionella pneumophila Pathogenesis

inhaled - lungs - alveolar - alveolar macrophages - alveolar macrophages destroyed - bacteria released - infect more alveolar macrophages

Legionella pneumophila Signs and Symptoms

fever, muscle aches, cough, shortness of breath

Archaea

prokaryotes, often in extreme environments, not known to cause disease in humans, no peptidoglycan in cell wall

methanogens

produce methane

extreme halophiles

live in extremely salty environments

extreme thermophiles

live in hot sulfurous water

fungi

eukaryotes, unicellular or multicellular, cell wall (chitin)

protozoa

eukaryotes, unicellular, variety of shapes, can be free-living or pathogenic, no cell wall

Naegleria fowleri

lives in freshwater, causes Primary Amebic Meningoencephalitis, waterborne(up the nose) transmission

Naegleria fowleri Pathogenesis

nasal mucosa —> brain —> destroys brain tissue

Primary Amebic Meningoencephalitis Signs/Symptoms

early: headache, fever, nausea, vomiting

later: stiff neck, confusion, lack of attention, loss of balance, seizures, hallucinations

microscopic algae

photosynthetic eukaryotes, common in fresh/saltwater, variety of shapes

multicellular animal parasites

eukaryotes, parasitic worms — helminths

Hookworm

Necator americanus, Ancylostoma duodenale, transmitted when larvae burrow through skin

Hookworm signs/symptoms

itching/redness at initial site of infection, cough, abdominal pain, diarrhea, anemia (low RBC)

viruses

acellular, can only reproduce using a host cell’s machinery, nucleic acid core (DNA or RNA), protein coat, envelope (sometimes)

Hantavirus

causes Hantavirus Pulmonary Syndrome, airborne transmission, reservoir: rodents (urine or feces is inhaled)

Hantavirus Pathogenesis

inhaled —> endothelial cells in lungs —> vasodilatation and increased blood vessel permeability

Hantavirus Pulmonary Syndrome Signs/Symptoms

early: fatigue, fever, muscle aches

late: pulmonary edema, cough, shortness of breath, shock (drop in BP)

Prions

proteinaceous infectious particles, no nucleic acid, can cause slow infections (months/years/decades before symptoms start), induce abnormal folding of proteins in brain

Taxonomy

science of classificationta

taxa

groups

Carl von Nägeli

proposed bacteria and fungi be placed into Kingdom Plantae

cellulose

compose plant and algae cell wall

peptidoglycan

compose bacteria cell wall

chitin

compose fungi cell wall

domain

largest, most broad taxon

species

smallest, most specific taxon

8 taxa

1. domain

2. kingdom

3. phylum

4. class

5. order

6. family

7. genus

8. species

3 domains

1. eukarya

2. bacteria

3. archaea

ribosomes

what are the differentiation of the 3 domains based off of?

Methionine

eukarya and archaea first amino acid in protein

Formylmethionine

bacteria first amino acid in protein

sensitive to antibiotics

bacteria

not sensitive to antibiotics

eukarya and archaea

domain: eukarya

protista, fungi, plantae, animalia

strains

subtypes of species

Escherichia coli O157:H7

gram-negative rod, found in guts of animals(cattle), causes: foodborne illness and hemolytic Uremic Syndrome, transmitted though fecal-oral route

Escherichia coli O157:H7 Pathogenesis

ingested —> stomach, acid resistant —> colonies intestines—> attaches to microvilli of intestinal cells—> releases Shiga-like toxin—> disrupts protein synthesis in intestinal cells —> cell death

foodborne illness signs/symptoms

severe abdominal cramps, bloody diarrhea, and vommiting

hemolytic uremic syndrome pathogenesis

shiga-like toxin crosses from intestine —> bloodstream—> bind to RBC—> destruction of RBC —> clog kidneys

symptoms of hemolytic uremic syndrome

anemia, low platelet count, kidney failure

endosymbiotic theory

organelles developed from endosymbiotic bacteria

true nucleus formation

plasma membrane of prokaryote folded in around DNA

mitochondria formation

aerobic bacteria engulfed

chloroplasts formation

photosynthetic bacteria (cyanobacteria) engulfed

evidence for endosymbiotic theory

• double membrane surround mitochondria/chloroplasts

• mitochondria and chloroplasts have their own DNA

• mitochondrial/chloroplast ribosomes similar to bacterial ribosomes

• mitochondria/chloroplasts reproduce like bacteria

• cells can’t create mitochondria/chloroplasts on its own

phylogeny

study of evolutionary history of organisms

hypotheses on the orgin of viruses

• arose from independently replicating strands of nucleic acids

• originated as RNA or DNA that escaped from host cell

  • developed from free-living cells

influenza virus

causes flu, RNA virus (8 segments of RNA), enveloped

December - March

seasonality of influenza

hemagglutinin (H)

binds to sialic acid on host cells

neuraminidase (N)

helps virus exit cell

Influenza A

infects humans and animals, seasonal, divided into strains based on H and N

Influenza B

seasonal epidemics, infects humans only

Influenza C

lacks seasonality, common in kids, infects humans and pigs, mild respiratory illness

influenza D

infects cattle

influenza transmission

droplet, fomites, can occur before signs/symptoms start

influenza virus pathogenesis

hemagglutinin binds to sialic acid receptors on epithelial cell so respiratory tract —> replicates inside respiratory epithelial cells —> released from cells and spreads to other respiratory epithelial cells

signs/symptoms of influenza

headache, fever, sore throat, muscle aches, chills, cough

antigenetic drift

accumulation of mutations as virus moves from one host to another

antigenetic shift

result of reassortment of human, avian, and swine influenza nucleic acids

pigs

what animal can be infected with swine, human, and avian influenzas

Zacharias and Hans Janssen

invented compound microscope

Robert Hooke

first to observe cells

wrote Micrographia