Biomed 3.1

Epedemiologists

Epedemiologists

They investigate health-related matters such as disease outbreaks and chronic illnesses by gathering information, examining data, and looking for patterns. 

Endemic

disease perpetually present in a community or population within a specific geographic area.  Malaria is endemic to parts of Africa, South America, and Asia

Sporadic

disease that occurs only occasionally.  E.coli infections caused by eating tainted food...these occur now and then (and are usually in the news)

Outbreak

 sudden increase in the occurrence of a disease in a localized area.  The common flu can spread rapidly through a community

Epidemic

disease that rapidly spreads to a large number of people in a population within a short period of time.  Western Africa Ebola epidemic (2013-2015)

Pandemic

epidemic that has spread across several countries or continents and affects a large number of people.  Covid-19 Pandemic

Nosocomial Infection

a hospital-acquired infection, or HAI

Infectious Disease

Infections that are caught or contracted

transmitted to others, they are considered infectious.

Pathogens

Infectious agents that cause disease

What does a healthy microbiome / normal flora do for us?

helps us digest food, protects us from invading organisms, and even provide us with some of the vitamins we need to stay healthy.

WE NEED NORMAL FLORA TO SURVIVE

Microbes

microscopic— tiny pathogens, visible only with a powerful microscope. 

Prions

through consumption of meat, contaminated medical equipment, or by receiving corneas or organs from infected individuals.

Damage: Cause normal proteins in the brain to fold abnormally

Treatment: no cure for prion diseases, but meds can slow

Viruses

made up of an outer protein shell, called a capsid, and either DNA or RNA.

Infection may occur through touch, saliva, blood, or sexual contact.

VIRUSES CANNOT REPLICATE ON THEIR OWN and Damage: host cells and tissues get destroyed

Treatment: TAntivirals may be used under certain circumstances

Bacteria

Living, microscopic, unicellular, prokaryotic organisms

occur through sinus through a wound, by ingesting contaminated food or water, inhalation, through sexual contact, due to an imbalance in our normal flora.

Damage: Invade cells, cause tissue damage, and produce harmful toxins.

Treatment: Antibiotics

Protists

animal-like organisms.

ingestion of food or water that has been contaminated with feces from an infected organism

Damage:infect the digestive tract, blood, or organs depriving a host of essential nutrients found in food. They can also cause tissue and organ damage.

Treatment: antiprotozoal meds

Helminths

Worms

'consumption of contaminated foods or water or by being bit by an infected insect

Damage: deprive the host of essential nutrients found in food and can cause tissue and organ damage.

Treatment: Deworming meds

Fungi

infect when the spores of the fungi, the reproductive cells, are inhaled or land on a host

Damage: Tissue damage

Treatment: Antifungals

Susceptible Host

Organism vulnerable to infection due to lack of immunity or defenses.

Resevoir

Where a pathogen resides (usually a human or another animal)

Chain of infection

pathogen resides in a reservoir,exits, and transmitted and causes an infection.  

Direct Contact

susceptible host touches an infected individual or is exposed to their body fluids via direct contact

Indirect Contact

Inhales airborne particles, touches an infected object or bitten by an insect or animal

Infectious Disease

number of organisms it takes to cause illness following exposure

SARS-coV-2 vs Covid-19

SARS-CoV-2 is the virus that causes Covid-19. SARS-CoV-2 is the pathogen, while Covid-19 is the disease it causes in humans.

RNA virus vs. DNA virus

RNA virus: Genetic material is RNA, not DNA. Examples include influenza and HIV. DNA virus: Genetic material is DNA, not RNA.

Innate Immunity

1st line

Non-specific immune defense mechanisms that we are born with

Aquirred Immunity

2nd line

acquired after cells are infected by a specific pathogen.

Passive Immunity

acquired from the mother.

Active Immunity

 acquired following infection (Natural) and recovery, or from a vaccine (Artifically)

Antigen

substance that triggers an immune response in the body. It can be a virus, bacteria, or other foreign substance.

T cells

type of white blood cell that play a central role in the immune response by recognizing and killing infected cells.

B cells

type of white blood cell that produce antibodies to help the immune system fight off infections and diseases.

Antibodies

proteins produced by the immune system to identify and neutralize harmful substances like bacteria and viruses.

Memory T cells

type of immune cell that "remembers" previous infections, enabling a faster and stronger immune response upon re-exposure.

Memory B cells

type of white blood cell that "remembers" past infections and quickly produces antibodies upon re-exposure to the same pathogen.

Inflammation

body's response to injury or infection, characterized by redness, swelling, heat, and pain at the affected site.

Herd Immunity

large portion of a community is immune to a specific disease, making the spread of the disease unlikely and protecting those who are not immune.

R-Naught

R0 = Number of new cases/number of existed cases

R0<1=One person will infect less than 1 person

R0=1 One person will only infect one person

R0>1 One person will infect more than 1 person

Etiology of disease

causes or origins of diseases and disorders.

Gross Morphology

bacterial colonies on agar.

Cellular Morphology

shape of their cells when viewed under a microscope).

Metabolize

Ability to digest certain compounds (after chemical testing). 

Microbioligist

 scientist who investigates the growth, structure, development, and other characteristics of microorganisms

Gram Stain

Mount one bacterial colony from petri dish onto microscope slide;

Petri Dish

used to culture bacteria

Nutrient Agar

 growth media that bacteria can grow on

Isolation Streak

sterile technique” in the “streak-plate method” to physically separate the different species of bacteria.

Binary Fission

One bacterial cell repeatedly divides,

resulting in billions of bacterial cells that form one colony.

Similar to mitosis but less steps

Aseptic Technique

refers to a procedure performed under sterile conditions

Streak Plate Method

successively dilutes the bacteria and individual bacterium are on the end of the streak

Why do we place petri dishes upside down

ensures that condensation does not drip onto the cultures causing the isolated colonies to mix back together in a pool of liquid

Gross Morphology

Color, Size, Shape, Height and Margins

Cell Morphology

shape of the bacterial cells.

What does cocci look like

circular

can form chains or individual, Groups of 2, 4, 8

What does Bacilli look like?

Rods

What does  spirillum mean?

Spiral

Only single

Staphylo

used for clusters

Strepto

used for chain

Diplo, Tetrad, sarcina

groups of 2, 4, 6

Gram Stain

test that differentiates bacteria into one of two groups based on the composition of their cell wall.

 peptidoglycan

sugar- and amino acid-rich substance.

Gram Negative

violet color that sticks to thick peptidoglycan layer

Gram Positive

cell wall with a thin peptidoglycan layer shielded by an outer membrane.  The Gram stain only stains the outer layer pink. 

outer lipopolysaccharide layer

• hydrophobic…this means that any hydrophilic antibiotic will stay away from the bacterium.

• can also induce a severe allergic reaction called septic shock.  Septic shock can cause a drop in blood pressure & death.

• Have porin pumps that pump antibiotics OUT of bacterial cell…which means the antibiotics can’t kill them