Unit 1

Chapters 1,3,9,7,15

Koch’s postulates step 1

the same organism must be present in every case of the disease but not present in healthy individuals

Koch’s postulates step 2

the organism must be isolated from the diseased host and grown as a pure culture

Koch’s postulates step 3

the isolated organism should cause the disease in question when it is inoculated into a susceptible host

Koch’s postulates step 4

the organism must be re isolated from the inoculated, diseased animal

epidemiology

incidence, distribution, and control of disease in a population

reservoir

animate or inanimate habit where a pathogen is naturally found that serves as a potential source of infection for susceptible hosts

vehicle transmission

contact with pathogen through a contaminated object or ingesting from food or water

vector transmission

pathogen has part of its life cycle in an arthropod ex) mosquitos

mortality rate

the number of deaths during a spcific time period

morbidity

the presence of disease in a population measured by incidence and prevalence rates

incidence rates

number of new cases of disease in a defined population during a defined time period

prevalence rate

how many cases exist during a given time frame in a given time frame

stages of disease

incubation, prodromal, acute, period of decline, convalescent

Louis Pasteur’s Swan-Neck Flask experiment

used to disprove spontaneous generation and use biogenesis

1 pure broth is heated and cooled with microbes trapped in the s neck, after days the broth is still pure

2 microbes trapped in s neck enter broth and broth is contaminated

3 airborne microbes enter broth and break flask neck and broth contaminated

concluded that microbe’s came from preexisting microbes in the environment

Redi’s experiment

seeing if maggots could arise from meat without flies, one jar was exposed to flies and maggotsd arise, another jar wasn’t exposed to flied and there were no maggots. This supported biogenesis theory

Needham boiled broth experiment

boiled broth is sealed in flasks and microbes arise , supporting spontaneous generation,

Spallanzani experiment

repeat of Needham, boiled brother for longer and used semipermeable barriers so air could not enter flasks, supporting biogenesis

Gram staining

staining technique to classify gram positive and negative bacteria based on their cell wall stricture (purple stain, iodine treatment, decolorization with alc or acetone, red dye applied for gram negative)

Gram negative

thin peptidoglycan layer, periplasmic space, outer membrane with lipopolysaccharides, stains red or pink

Gramp positive

thick peptidoglycan layer, no outer membrane, stains purple

shapes of bacteria

bacillus (rod), coccus (circle). coccobacillus, vibrio (comma), spirochetes (spiral)

arrangement of bacteria

diplococci (paired cocci), streptococci (chains of cocci), staphylococci (grapelike cluster of cocci), diplobacilli (paired bacillus) streptobacilli (chains of bacilli), palisade (cluster of bacilli)

flagella

mobility, gram positive have two rings used to secure to the flagella and gram negative have four rings used for anchoring, use the run and tumble to response to stimulus, lophotrichous (cluster of flagella at one pole), amphitrichous (flagella at both ends), and peritrichous (flagella all over the cell surface)

fimbriae

short bristle-like structures that use adhesive properties to stick to others or surfaces to create biofilm, common in gram negative

pilli

longer, more rigid and numerous than fimbriae, aid in gene transfer

glycocalyx

sticky carbohydrate layer that sticks to host tissues or surfaces and aids in protection

slime layer

unorganized and is loosely attached to the glycocalyx

capsule

organized and is highly associated with the glycocalyx

carboxysomes

inclusion body that contains carbon fixing enzymes

magnetosomes

inclusion bodies that accumulate magnetic iron

endospores

metabolically inactive structures that allow certain cells to enter a dormant state, when conditions become favorable spores germinate back into vegetative cells (actively growing)

sporulation

processes of forming an endospore (dna copy, package dna and ribosomes, surround spore core with heat and chemicals resistant layers, release)

Sodium potassium pump

pumps three sodium ions out of the cell and two potassium ions into the cell using one atp per cycle

bacteria growth phase

lag (delay so cells can adjust to their environment), log (rapid exponential growth), stationary (nutrients are depleted and waste accumulates and growth rate levels off), death (cell death is exponential)

Cell nutrient requirements

carbon, hydrogen, nongaseous oxygen, nitrogen

also s, p, k,na, c, mg, cl

cell count

direct method of counting individual cells or colonies, automated or manual procedures

coulter counter

direct method, machine that counts the number of cells as they pass through a thin tube

flow cytometer

direct method, laser light to detect cells passing through a narrow channel

viable plate count

direct count, direct enumeration of bacteria using agar plates using spread plate or pour plate method

turbidity

cloudiness, indirect counting cells methods, cloudy means more cells, less cloudily means less cloudy

therapeutic index

the maximum safe dose found by doing the maximum tolerated dose divided by minimal effective dose

toxicity

kidneys and liver are key organs that metabolize and eliminate drugs, making them susceptible to damage by drug

nephrotoxic

kidney toxic, leading cause is antimicrobials, aminoglycosides and extended use of nonsteroidal anti-inflammatory drugs

hepatoxic

liver damage, antimicrobial drugs are leading agents of drug induce liver injury (DILI)

½ life

time it takes for half of a dose to be eliminated by the body, determines frequency of administration, short one requires frequent administration, long vise versa

quinolones/fluroquinolones

target DNA replication, cause headache, dizzy, insomnia, tendon rupture

Rifamycin’s

bind to RNA polymerase, broad spectrum, side effects incluse gi upset, fatigue, dizzy

sulfonamides

folic acid target, broad spectrum and bacteriostatic, cause uv light sensitivity, oral/iv/topical

ribosome drug target

target is 70S ribosome and 30S subunit, drugs block binding of tRNA, macrolides, tetracyclines (broad, bacteriostatic), aminoglycosides (narrow, short half-life, causes hearing loss and nephrotoxicity), lacosamide, phenicol

membrane structure drug target

polypeptides, narrow

ways microbes can evade antimicrobial drugs

altering a drug’s target, inactivating the drug, or reducing the drug concentration

antimicrobial resistance

microbe is not affected by a drug intended to inhibit or eliminate the pathogen

cell wall synthesis drug target

beta-lactams including penicillins, cephalosporins, carbapenems, and monobactams

penicillins

for gram + and select gram - , semi synthetic are absorbed better, can have allergic reactions, p. chrysogenum

Cephalosporins

A. chrysogenum, largest collection of beta-lactam drugs, broad, bactericidal, rash and Gi upset, used for patient’s w penicillin allergy or resistance, 5th gen can combat MRSA/ORSA

Carbapenems

broad, only injectable, effective against multidrug resistant bacterial strains, rash and Gi, for healthcare acquired infections (HAI’s) and patients who have infections that didn’t response to first-line therapies

Monobactams

narrow, promotes cell lysis, effective against gram - , only Aztreonam,

Non-Beta Lactams that target cell wall synthesis

glycopeptides, polypeptides, combo

glycopeptides

lack the beta lactam ring making them not susceptible to beta lactamases, narrow spectrum, cause nausea and hearing issues

polypeptides

narrow spectrum for gram + (staph), mild itching ex) bacitracin

combination

combo drugs can interfere with mycolic acid and cause liver toxicity ex) isoniazid