midterms -microbiology

microbiology

The study of organisms too small to be seen by the unaided eye

Clinical Microbiology

Study of microbial pathogens considered to be health threats

Diagnostic Microbiology

Examination and identification of organisms through laboratory tests

Food Microbiology

Practical application and use of beneficial microorganisms in food processing

parasitology

study of parasites

mycology

study of fungi

bacteriology

study of bacteria

virology

study of viruses

Girolamo Frascastoro

determined that diseases can be passed in three ways rapidly and transfer from infector to the infected: direct contact, carriers (clothing), air born

Anton van Leeuwenheok

Father of Bacteriology and Protozoology, Discovered many life forms he called

‘animalcules’, made a single lens microscope

Francesco Redi

Disputed the Theory of Spontaneous Generation - experiment of decaying meat in 1668

experiment: jars and maggots

John Needham

“life force” that causes inanimate matter to spontaneously come to life = bacteria

experiment: boiled nutrients in a sealed flask=microbial growth

Lazzaro Spallanzani

Observed that microbes move through the air as possible source

of contamination and can be destroyed by boiling.

experiment: heated sealed vial=no microbial growth

Lousis Pasteur

Developed the principles of vaccination, microbial fermentation, and pasteurization

joseph lister

discovered antiseptic surgery, use of carbolic acid (phenol) as a chemical sterilizing agent

hans christian gram

Gram staining technique which distinguishes two major groups of bacteria: Gram-positive

and Gram-negative

alexander flaming

Discovered the first antibiotic, Penicillin G, from a mold, Penicillium notatum

Robert Koch

koch postulates - 4 principles to linking microorganism to disease

CELL MEMBRANE

The lipoprotein layer that surrounds the cytoplasm. Regulates the transport of solutes in and out of the cell.

CELL WALL

The semi-rigid casing that provides structural shape and support to the cell

RIBOSOMES

Site of protein synthesis. Gives granular structure to the cytoplasm

NUCLEOID

The region where the DNA is concentrated

CAPSULE

Protective layer of a bacterium that resist phagocytosis and desiccation

PILI

Hair-like proteinaceous structures that extend from the cell membrane into the external environment

two types: somatic pili and sec pili

FLAGELLUM

The structure that allows the bacteria to move

ATRICHOUS:

absence of flagellum

MONOTRICHOUS:

one polar flagellum

AMPHITRICHOUS:

single flagellum on both ends

LOPHOTRICHOUS

tuft of flagella on either end or both ends

PERITRICHOUS

flagella all around the organism

INCLUSION BODIES

Food reserves of the bacteria

Babes-Ernst bodies

Corynebacterium diphtheriae food reserves

Much’s granules

Mycobacterium tuberculosis food reserves

Sulfur granules

Nocardia and Actinomyces species food reserves

Bipolar bodies

Yersinia pestis food reserves

SPORES

Structures that allow the bacteria to resist sterilization. Composed of calcium dipicolinate

calcium dipicolinate

what spores are made of

Terminal

Clostridium tetani

Subterminal

Clostridium botulinum

Central

Bacillus anthracis

cocci

spherical bacteria shape

bacilli

rod bacteria shape

spiral

long bacteria shape

Aerobes

require oxygen for growth (obligate, facultative, microaerophilic)

Anaerobes

grow best in an atmosphere of reduced oxygen tension

Capnophiles

need 5-10% carbon dioxide to live, placed in candle jars

Autotrophs

able to make energy-containing organic molecules from inorganic raw material by using basic energy sources such as sunlight

Heterotrophs

organisms must make use of food that comes from other organisms in the form of fats, carbohydrates and proteins

Psychrophile/cryophile

0-15°C

Mesophile

20-45°C (human pathogens

Thermophile

50-60°C

Hyperthermophile

80-113°C

Acidophile

pH 0-5.5 (Sulfolobus)

Neutrophile

pH 5.5-8.0 (E.coli)

Alkalophile

pH 8.5-11.5 (Vibrio cholerae)

lag, log, stationary, death or decline

bacterial growth curve

log phase

exponential increase, second phase

lag phase

no increase in living bacterial cells, first stage

stationary phase

bacteria death and division is equal, third stage

death or decline stage

exponential decrease in bacteria, final phase

methylene blue

simple stain; used to observe size, shape, and uniformity of staining

Gram staining or acid fast

differential stain, used to distinguish between group of bacteria

crystal violet, iodine, alcohol, safranin

gram stain procedure

BACTERIOSTATIC

agents that inhibit bacterial growth

BACTERICIDAL

agents that actively kill bacteria

antibiotics

function: Inhibits cell wall, protein, and nucleic acid synthesis, Cell membrane destruction

Minimal inhibitory concentration

Lowest concentration of antimicrobial agent that inhibits bacterial growth.(bacteriostatic)

Minimal bactericidal concentration

Lowest antibiotic concentration that results in 99.9% death of the bacterial population.(bactericidal)

ANTIBIOTIC SUSCEPTIBILITY TESTING

therapeutic guidelines, Indicates which antibiotic is effective in killing the bacteria causing the infection or disease

broth dilution 

lowest concentration needed for effect

DISK DIFFUSION METHOD

Determines the susceptibility of bacterial pathogens to antimicrobial agents, zone of inhibition