MicroBio Exam 1

Florence Nightingale

\-Founder of modern nursing

\-Demonstrated that infectious diseases resulted in high mortality rates

Robert Hooke

built the first compound microscope

Anton van Leeuwenhoek

\-first to observe single celled microbes

\-was able to get better magnification

Lassaro Spallanzani

\-tried to disprove spontaneous generation

\-sealed a flask with broth boiled it=no growth

Louis Pasteur

\-used a swan neck flask that was open on one end

\-allowed oxygen to get in, but kept boiled broth clean of microbes

\-developed the first vaccines (fowl cholera, rabies)

John Tyndall

-found opposite results as Pasteur

Robert Koch

-founder of scientific method of microbio

Richard J. Petri

developed the petri dish

Fanny Angelina Hesse

suggested agar to be used in petri dish instead of gelatin

Lady Mary Wortley Montagu

introduced the practice of smallpox inoculation

Dr. Edward Jenner

took cowpox, infected James, James got mild disease.

took smallpox, infected James, James was immune

Ignaz Semmelweis

advocated hand washing in chlorine to prevent transmission of disease

Joseph Lister

\-noted half of amputee patients died of sepsis

\-began to use antiseptic agents to treat wounds

Alexander Fleming

discovered penicillin to kill bacteria

Howard Florey & Ernst Chain

purified penicillin

Dmitri Ivanovsky

studied tobacco mosaic disease; agent of transmission could pass through a porcelain filter that blocked all known microbes

Martinus Beijerinck

the agent of tobacco mosaic disease is not a bacterium, because it passes through a filter that retains bacteria

Wendell Stanley

crystallized tobacco mosaic virus

Sergei Winogradsky

Studied microbes in their natural habitat

Lynn Margulis

\-proposed that eukaryotic organelles were able to develop complex compartments such as mitochondria and chloroplasts by engulfing and merging with bacterial cells

\-Endosymbiotic Theory

Carolus Linnaeus

called the microbial world "chaos"

Ernst Haeckel

\-determined microbes are neither plant or animal

\-called third kind of life (monera)

Herbert Copeland

divided Monera into two groups: eukaryotic protists and prokaryotic bacteria

Robert Whittaker

added Fungi as a 5th kingdom of eukaryotic microbes

Carl Woese

three domain based on r RNA (eukarya, bacteria, archaea)-2 kinds of prokaryotes

Frederick Griffith

discovered transformation in bacteria

Oswald Avery

showed that the transforming substance is DNA

Rosalind Franklin

used x-ray crystallography to determine that DNA is a double helix

James Watson & Francis Crick

discovered the complementary bases and antiparallel nature of DNA

Prokaryotes

\-lack a nuclear membrane

\-include bacteria and archaea

Eukaryotes

\-possess a nuclear membranes (nucleus)

\-include fungi, protozoa, algae, plants & animals

What are the 3 domains of life?

Bacteria (pro), Archaea (pro), Eukarya (euk)

What are viruses?

\-noncellular

\-4-100nm in size

\-can cause disease

What is the endosymbiotic theory?

-both mitochondria and chloroplasts contain their own DNA sequences

normal microbiota

collection of bacteria, archaea, and eukaryotic microbes usually colonizing our bodies

mutualism

relationship in which community members and host both benefit

colonization

ability of a microbe to stay affixed to a body surface and replicate

adhesions

proteins on surface of microbes that allow them to attach to and colonize epithelial cells lining mucous membranes

environmental factors

Different strains can enter/leave our bodies depending on what we eat, how we exercise, and whom we meet

Susceptibility to pathogens

As our microbiota changes, it can make up moresusceptible to pathogens, affect our immune system,and even change our weight

Pathogenicity

The ability of an organism to cause disease

Parasite

Any organism that colonizes and harms its host

Infection

Occurs when a pathogen or parasite enters or begins togrow in/on a host

Primary pathogens

Able to breach defenses of a healthy host

Opportunistic pathogens

Cause disease in a compromise host

Latent stage

Organism within a host but can not be detected by culture

Virulence

How well a pathogen can fight/off the host defenses/ how harmful the pathogen is to the host

Infectious dose 50% (ID50)

The number of bacteria or virions required to cause disease symptoms in 50% of an experimental group of hosts

Lethal dose 50% (LD50)

The number of bacteria or virions required to kill 50% of an experimental group of animal hosts

Invasion

The ability of some pathogens to enter and live inside a host cell

Invasiveness

The ability of a bacterial pathogen to rapidly spread through tissues

narrow host range

can infect only humans

broad host range (zoonotic)

can infect many different animals in addition to humans

Attachment

Adhesions & their specific receptors

Immune avoidance

Altered surface antigens, secretion of"all is well" signals, apoptosis signals

Disease

Disruption of the normal structure of function of anybody part, organ, or system that can be recognized by a characteristic set of symptoms and signs

Infectious disease

A disease caused by a microorganism (bacterial, viral or parasitic) that can be transferred from one host to another Basic concepts of disease

Acute

Symptoms develop rapidly (strep throat)

Chronic

Symptoms develop gradually over weeks or months and are slow to resolve (tuberculosis)

Sub-acute

Symptoms take longer to develop than acute but arise more quickly than chronic (bacterial endocarditis)

Latent

Infection occurs after an acute episode, the organism is present but symptoms are not present (ex. cold sores due to Herpes virus)

Bacteremia

Presence of bacteria in blood, usually transient, no replication(Streptococcus mutans after dental procedure)

Septicemia

Presence and replication of bacteria in blood (bubonic plague)

Viremia

Presence of viruses in the blood (HIV)

Toxemia

Presence of toxins in the blood (diphtheria, toxic shock syndrome)

Primary infection

Infection in a previously healthy individual (syphilis)

Secondary infection

Follows primary infection (Haemophiles influenzae after viral influenza infection)

Iatrogenic infection

Infection transmitted from a health care worker to a patient (some Staphylococcal septicemias)--\> person

Nosocomial infections

Infection acquired during a hospital stay (MRSA - methicillin resistant Staphylococcus aureus)--\> location

Sign

Something that can be observed by a person examining a patient (runny nose, rash)

symptom

Something that can only be felt by the patient (pain, malaise)

syndrome

Collection of signs and symptoms that occur together and signify a particular disease or infection

incubation period

time after the microbe first infects a host but before the first signs of disease

Prodromal phase

Short period of vague symptoms and malaise, can serve as a warning of more symptoms to come but may not be noticed

Illness phase

Typical symptoms and signs of the disease appear and fever may be present, acme (climax) is the point where the disease is most severe

Decline

Symptoms begin to subside, fever resolves

Convalescence

Period after symptoms disappear and patient recovers

Opportunistic pathogen

Organisms that cause disease by taking advantage ofa host's increased susceptibility to infection

Primary pathogen

Cause disease in individuals who are healthy

Direct contact transmission

Organisms may spread directly from person to person

Indirect transmission

Organism may spread indirectly through an intermediary which may be living or non living

Carrier

Individual who harbors a potential disease agent but does not have signs or symptoms of the disease

Endemic

Always present in a community and seen at a low rate

Epidemic

Many cases developing in a community in a short time

Pandemic

An epidemic that spreads worldwide

Fecal-oral

Through mucosal surfaces of gastrointestinal tract

Skin

Through epithelial surfaces

Respiratory

Through mucosal surfaces of respiratory tract

Urogenital

Through mucosal surfaces of genital and urinary tracts

Parenteral

Through injection into blood stream

What are host factors of disease?

\-age

\-genetic makeup

\-hygiene and behavior

\-nutrition and exercise

\-underlying non infectious diseases or conditions

\-occupation

\-immune status and immunopathogeneis

what is the size of eukaryotic microbes?

10 - 100 μm

what is the size of prokaryotic microbes?

0.4 - 10 μm

what are the different microbial shapes?

\-Bacilli - rods

\-Cocci - spheres

\-Spirochetes - cork screw

\-Spirilla - spiral

Resolution

the smallest distance at which two objects can be separated and still distinguished

Magnification

an increase in the apparent size of an image to resolve smaller separations between objects

How do you calculate total magnification?

ocular (10) x objective

how do you prepare specimens for observation with a microscope?

a simple way to observe microbes is to place them in a drop of water on a slide with a cover slip (wet mount)

What are the staining techniques?

\-simple stain- adds dark color to cells, but not the medium

\-differential stain (gram stain)- stains one kind of cell but not the others

what are the different types of differential stain?

\-flagella stain

\-Ziehl-Neelson acid-fast stain

\-endospore stain