Microbiology Final

scientific nomenclature

genus’s 1st letter is capitalized

species’ 1st letter is lowercase

both are italicized

ex.) Escherichia coli

bacteria

unicellular prokaryote

reproduces by binary fission

contains peptidoglycan in its cell wall

can be cocci, bacilli, or spiral

archaea

unicellular prokaryote

lives in extreme environments (methanogens/halophiles/thermophiles)

antibiotic resistant

fungi

unicellular (yeast) or multicellular (molds)

eukaryotes'

chitin in their cell wall

molds→ reproduce using spores

yeasts→ reproduce using budding

protists (protozoa)

unicellular eukaryotes

classified by motility (pseudopods/flagella/cilia)

reproduce asexually or sexually

algae

cellulose cell wall

uni or multicellular eukaryote

produces O2

viruses

noncellular

contains a protein coat

contains DNA or RNA

helminths

eukaryote

round and flat worms

uses of microbes

bioremediation→ cleaning up toxic substances (ex. oil spill, mercury)

producing foods such as vinegar, yogurt, and cheese
human microbiota acts as a nonspecific defense

plays a role in vitamin synthesis

Hooke

observed the first cells

Leeuwenhoek

observed the first microorganisms

spontaneous generation

living things arise from nonliving material

Needham’s sealed broth supported this

biogenesis

living things only arise from preexisting cells

proved by Pasteur’s swan-neck experiment AND Redi’s meat jar experiment

Koch’s postulates

Find the microbe in every sick person but not in healthy people

Take the microbe out of the sick person and grow it in a lab

Put that microbe into a healthy host

Take the same microbe back out of the newly sick host

Semmelweis

prevented childbirth fever by implementing handwashing

lister

disinfected surgical area using phenol to prevent post-surgical infection

koch

proved germ theory by using anthrax from cattle

domains used to classify bacteria

bacteria → peptidoglycan cell wall

archaea→ no peptidoglycan

eukaryote → membrane bound organelles

biofilm

a community of microorganisms attached to a surface and enclosed in a protective matrix (slime layer)

virus

tiny infectious particle that contains DNA or RNA and must use a host cell to reproduce

total magnification

ocular lens (10x) x objective lens

parfocal

little refocusing needed when switching objectives

resolution

the ability of a microscope to distinguish two objects that are very close together as separate objects

refractive index

how much light bends when it passes through a substance

compound light microscope

used to view small specimines

ex. bacteria, fungi, protist

darkfield microscope

used to look at Treponema pallidum

fluorescence microscope

Uses fluorescent dyes on antibodies to detect and identify specific microbes

electron microscope

used to see ultra small substances

ex.) viruses

simple stain

uses dye to distinguish shape, size, and arrangement

gram stain

apply crystal violet

add mordant (iodine)

add decolorizer

add safranin

gram stain

add carbolfulxin

add acid alcohol

add methylene blue

special stains

silver stain, capsule stain, endospore stain

compound light microscope

ocular lens- piece you look through

revolving nosepiece

objective lens (different objectives)

stage

condenser- focuses light on specimen

glycocalyx

capsule or slime layer prevents phagocytosis helps the cell to adhere

axial filaments

in spirochetes help with motility

pili

short appendages that help w/ DNA transfer

inclusions

storage compartments for nutrients

flagella

protein appendage that aids in motility towards or away from stimuli

fimbriae

hair-like appendages that help w/ adherence

plasmid

circular DNA molecule found in bacteria

gram positive

thick peptidoglycan layer

contains teichoic acids

produces endotoxins

susceptible to penicillin

resists decolorization and stains purple

gram negative

thin peptidoglycan layer, thick lipid layer

contains a periplasmic space

contains outer membrane

produces endo and exo-toxins

decolorizes and stains pink

endospores

dormant, resting structures

become active through germination (endotoxin is released as well)

survive in harsh conditions

present in gram positive bacteria

resistant to chemicals, lack of water, and heat

endosymbiotic theory

states that eukaryotic cells evolved from prokaryotes

- mitochondria and chloroplasts’ size and shape resemble bacteria

-they contain circular DNA like bacteria

-they contain the same-sized ribosomes as bacteria

facitated diffusion

movement through transport protein

osmosis

movement of water passively from an area of high water to an area with low water

active transport

movement against gradient w/ use of ATP or transport protein

group translocation

substance is transported and it simultaneously starts a chemical change

hypotonic

<.85%

causes cell lysis

higher solute concentration in bacteria, water rushes in

hypertonic

>.85%

causes plasmolysis

lower solute concentration in bacteria, water rushes out

enzyme action

substrate binds to enzyme’s active site

enzyme-substrate complex forms

substrate is transformed into products

products are released and enzyme is released

enzyme components

holoenzyme (whole enzyme)

apoenzyme (protein portion)

cofactor (activator)

redox reactions

generation of ATP using oxidation (loss) and reduction (gain)

ATP generation

glycolysis→ 2 ATP, 2 NADH, 2 pyruvate produced

krebs cycle→ 2 ATP, 4 CO2, 6 NADH, 2 FADH

electron transport chain→ O2 is the final oxygen acceptor

chemoautotroph

carbon source: CO2

energy source: inorganic compounds

photoautotroph

carbon source: organic compounds

energy source: light

chemoheterotroph

carbon source: organic compounds

energy source: organic compounds

photoheterotroph

carbon source: organic compounds

energy source: light

aerobic respiration

O2 final electron acceptor

38 ATP produced

anerobic respiration

final electron acceptor is an inorganic compound (nitrite, nitrous oxide, sulfate, carbonate)

more than 2 less than 38 ATP produced

fermentation products

lactic acid, ethanol, acetone, isopropyl alcohol

psychrophiles

extreme cold loving

below 0 degrees Celsius

psychrotrophs

grows between 0-20 degrees celcius

causes food spoilage in fridges

mesophile

grows at 25-40 degrees celcius

human blood

MOST ORGANISMS IN THIS CLASS

thermophile

heat loving grows between 50-60 degrees celcius

extreme thermophile

grows at 80 degrees Celsius or higher

obligate aerobes

require oxygen

facultative anaerobes

growth with or without oxygen

obligate anaerobes

harmed by oxygen

aerotolerant anaerobes

not affected by oxygen

microaerophiles

require low oxygen

lag phase

intense metabolic activity, preparing for growth

log phase

exponential increase in population

stationary phase

cell birth is equal to cell death

death phase

cell death exceeds cell birth

direct methods of measuring cell growth

plate counts

filtration (pores capture bacteria)

direct microscopic count (counting bacteria)

most probable number

indirect methods of measuring cell growth

turbidity (cloudiness)

metabolic activity

dry weight

disinfection

removal of all vegetative (nonendospore-forming) bacteria on structures

heat

uses an autoclave to denature proteins at 121 degrees Celsius at 15 psi for at least 15 minutes

most common method

used with media and cultures

direct flaming/incinerators

dry heat kills by oxidation

used with metal wires and diseased animals

taxonomy

science of classifying organisms

treponema pallidum

gram negative spirochete

causes syphilis

transmitted sexually and congenitally

diagnosed by serology

treated with penicillin

borrelia burgdorferi

gram negative spirochete

causes lyme disease

transmitted through vectors

diagnosed through serology

treated with doxycycline

reservoir= field mice

vibro cholerae

gram negative bacilli

causes cholera

transmitted fecal-orally

diagnosed using selective and differential media

treated with oral rehydration

campylobacter jejuni

gram negative bacilli

causes gastroenteritis

transmitted fecal orally

diagnosed with use of CAMPY agar

treated with oral rehydration

helicobacter pylori

gram negative bacilli

causes gastric ulcers

transmitted fecal orally

diagnosed by a stool antigen test

tre4ated with Pepto-Bismol and antibiotics

pseudomonas aeruginosa

gram negative bacilli

causes wound infection

transmitted opportunistically or nosocomially (hospital)

diagnosed by bacterial culture

treated with antibiotics

legionella pneumophilia

gram negative bacilli

causes Legionnaires’ disease

transmitted through air or water (air conditioning)

diagnosed by fluorescent antibody testing

treated with erythromycin

Neisseria gonorrhea

gram negative cocci

causes gonorrhea

transmitted sexually

diagnosed by gram stain

treated with serology

Neisseria meningitis

gram negative cocci

causes meningitis

transmitted by droplets

diagnosed by CSF culture

treated with antibiotics

Eschericha coli

gram negative bacilli

causes UTI and gastroenteritis

transmitted opportunistically and nosocomially (hospital)

diagnosed by urine culture

treated with antibiotics

salmonella enterica

gram negative bacilli

causes gastroenteritis

transmitted fecal orally (consumption of raw poultry, eggs)

diagnosed by stool culture

treated with fluid replacement

salmonella typhi

gram negative bacilli

causes typhoid fever

transmitted fecal orally

diagnosed by blood culture

treated with antibiotics

shigella

gram negative bacilli

causes shigellosis

transmitted fecal orally

diagnosed by stool culture

treated with antibiotics

E. coli 057: H7

gram negative bacilli

Causes dysentery (bloody diarrhea)

transmitted by close contact with calves

diagnosed by stool culture

treated by oral rehydration

Bordetella pertussis

gram negative bacilli

causes whooping cough

transmitted by droplets

diagnosed by nasopharynx swab

treated with erythromycin

bacillus anthracis

gram positive bacilli

causes anthrax

transmitted by inhalation of endospores

diagnosed by gram stain

treated with antibiotics

needs oxygen to grow

clostridium tetani

gram positive bacilli

causes clostridium

parenteral route transmission (puncture wound)

diagnosed by detection of toxin in specimen

treated with antitoxin

staphylococcus aureus

gram positive

causes folliculitis

transmission by direct contact and droplets

diagnosed by bacterial culture

treated with antibiotics

staphylococcus epidermidis

gram positive

causes catheter infection

opportunistic pathogen

diagnosed by gram stain

treated with antibiotics