Bacteria and antibiotics

Types of bacteria

archaebacteria and eubacteria

What are archaebacteria?

Bacteria that exist and thrive in extreme conditions, like (Extremophiles)

high temperatures,

acidic and sulphur-rich environments,

salty environments, where salt exists in high concentrations that are deadly to most forms of life

What are Eubacteria?

True bacteria. They have peptidoglycan in their cell walls. (Common bacteria we see every day)

Cell parts in a bacterium

Cell wall

Plasma membrane

Cytoplasm

Nucleoid

Ribosomes

Capsule

Flagella

Pili (fimbriae)

Plasmids

What does the cell wall do in bacteria, and what is it made for?

It is a thick, rigid outer layer that provides shape and protection, it is made of peptidoglycan.

Plasma membrane. (function, what does it enclose, and why can it perfrom that function)

Encloses the cytoplasm and regulates the movement of substances going in and out of the cell as it is partially permeable.

Cytoplasm, what is it made of, what does it contain and what occurs there?

Gel-like substances containing water, enzymes, nutrients, and other molecules, where cellular processes occur.

Nucleoid what does it contain, and what encloses it? (or is it not enclosed?)

The region containing the bacteria’s chromosome (DNA), which is not enclosed by a membrane (suspended within the cytoplasm)

Ribosomes (functions)

The structure responsible for protein synthesis, found in the cytoplasm. (Uses DNA to make proteins)

Capsules (functions, location and what cells has it)

A layer outside the cell wall, providing protection and aiding in attachment to surfaces

EXISTS USUALLY IN PATHOGENIC BACTERIA (not all bacterial cells have it)

Flagella/flagellum (plural/singular) (function)

Long, whip-like appendages used for motility(movement)

Pili (frimbriae/fimbria) (plural/singular) (functions and characteristics) (not in syllabus, but good to know)

Short, hair-like structures that aid in attachment to other cells or surfaces

Plasmids (function and characteristics)

Small, circular DNA molecules that can carry genes for antibiotic resistance or other beneficial traits (to give them a selective advantage)

shape of bacteria

Cocci/coccus (circular)

Bacilli (rod)

Spriochetes(more turns)/spirilla (helical)

Vibrios (curved)

Arrangement of bacteria

Strepto- (in chains)

Staphylo- (clusters)

Diplo- (in pairs)

Types of bacteria (disease grouping)

Pathogenic bacteria (pathogens)

non-pathogenic bacteria (non harm-causing)

What is a pathogen

organisms that cause disease to its host

Non-pathogenic bacteria resides on? Also, what do they form?

Often resides on the surface of animals without causing harm (either on body surfaces or lining the digestive tract.)

(They usually form the normal flora of the organism. Some are beneficial and are involved in the manufacture of various foods.)

Escherichia coli function in ldigestive system

They reside in the large and small intestine, which breakdown undigested sugars and produce biotin and vitamin K

How do bacterial infections spread? (ways)

Airborne/droplet

Direct/indirect contact

Vector

Vehicular

Airborne/droplet (how it spreads bacteria)

Contaminated dust/droplets of water/mucus (inhalation/contact)

Direct/indirect contact (how it infects)

Skin/mucous membrane contact contaminated surfaces (indirect contact)

Skin/mucous membrane contact other infected animals (direct contact)

Vector (how it infects)

A living organism (usually an insect or arthropod) that carries and transmits a pathogen between hosts, typically without getting sick itself.

they transfer the pathogen to us when they bite/feed on us

Vehicular (how it infects us)

Consumption of contaminated food or water

How do we easily get salmonella

Eating uncooked/undercooked meat/poultry/seafood/eggs

Eating contaminated fruits and vegetables

Drinking contaminated water/unpasteurized milk

Not washing hands while preparing/consuming food.

Cholera can spread in places with? Where does it live in? How does it spread? Does direct contact risk contraction?

Inadequate water treatment, poor sanitation and inadequate hygiene.

They live in brackish rivers and coastal waters

People can contract cholera when they consume contaminated food/water

Direct contact is not a risk factor for transmission.

STDs (contraction ways)(Chlamydia)

Having sexual intercourse with someone who has STD.

An infected person who is pregnant can give the infection to their baby during childbirth

Non-pathogenic bacteria. What are their characteristics?

They do not cause disease/death/harm to organisms.

Staphylococcus epidermidis - on the normal skin surface, a potentially deadly bacterium

Bifidobacteria are a resident of the large n small intestines, useful as a probiotic. MAIN FUNCTION IN THE HUMAN BODY - BREAKS DOWN DIETARY FIBRE (that we cannot break down ourselves) TO RELEASE ESSENTIAL NUTRIENTS

Brevibacterium linens - used in cheese production

Antibiotic made from a fungus (the name of the fungus and the antibiotic)

Penicillium and penicillin

Antibiotic definition

Substances produced by the natural processes of some microorganisms that can KILL or INHIBIT the growth of bacteria that are used to treat bacterial infections

Antibiotics are produced in? What are the benefits of this?

Nature by soil bacteria and fungi

gives microorganism that produces it an advantage when competing for food, water and other limited resources in a particular habitat as antibiotic kills off their competition

Bacteria can be? (beneficary spectrum)

Neutral, harmful or beneficial

Types of antibiotics

Bacteriostatic

Bactericidal

Bacteriostatic (characteristics)

Inhibit the growth of bacteria in organisms.

Bactericidal

Kill bacteria (lethal self-destruction)

Characteristics of a GOOD antibiotic

to be selectively toxic to the pathogen but non-toxic to the host’s cells

to be bactericidal rather than bacteriostatic

to be soluble and not affected by dilution

not to be broken down/excreted prematurely

not to cause allergies/predispose the host to other infections

source of antibiotics

nature is the source of most antimicrobial drugs

most antibiotics are produced by bacteria or fungi

one example each:

bacterial source:

streptomyces & bacillus

Fungal source:

Penicillium & Cephalosporium

Antibiotics can? (relating to beneficial bacteria)

kill beneficial bacteria that protect us. (and keep resistant bacteria in check)Without them, pathogens (and resistant bacteria) have an even bigger advantage due to reduced competition for resources, and this allows them to thrive and multiply.

Pathogens are (antibiotics)

susceptible to antibiotics, but they have evolved ways to survive.

antibiotics produced by the bacterial genus Bacillus (examples)

Bacitracin

Polymyxin

Staph bacteria

germs that commonly live on the skin and in the nose are called

Staphylococcus or “staph” bacteria

usually it doesnt cause any harm

BUT IF THEY GET INSIDE THE BODY THROUGH A BREAK IN THE SKIN, THEY CAUSE AN INFECTION

but it is treated with antibiotics

when common antibiotics dont kill it, the bacteria has become resistant to those antibiotics. So it is called MRSA (Methicillin-resistant staphylococcus Aureus)

Tuberculosis

results from an infection with Mycobacterium tuberculosis

• can be cured with a combination of first-line drugs taken for several months

• MDR-TB occurs when a strain of it is resistant to isoniazid and rifampin, two of the most powerful first-line drugs

• XDR-TB occurs when a strain of it is resistant to isoniazid and rifampin, as well as any fluroquinolone and atleast another injectable drugs like

• Amikacin

• Kanamycin

• Capreomycim

• (these are second line drugs^^^)

This can also be resistant to additional drugs, greatly complicating therapy

What do super bugs do? (in terms of mutation)

They constantly mutate or acquire new resistance against antibiotics

Old antibiotics such as penicillin are no longer effective

hence we need to find new antibiotics for treatment

antibiotic resistant bacteria spread way in food industry, and hence we need to?

Antibiotic resistant bacteria can spread between people, acquired through contaminated food products, contracted from animals so preventing antibiotic resistant infections requires that we all use antibiotics responsibly

Antibiotics are not effective against?

Diseases caused by viruses.

Viral infections or against blocked, running nose and common cold, flu.

Also, bronchitis (a respiratory infection) are not bacterial infections so antibiotics are not effective

correct usage of antibiotics is? (exampel)

Antibiotics for strep throat, which is caused by bacteria.

BUT NOT FOR MOST SORE THROATs → caused by viruses

How does antibiotic resistance occur?

Over-prescribing antibiotics

Patients not finishing their treatment

Overuse of antibiotics in livestock and fish farming

Poor infection control in hospitals and clinics

Lack of hygiene and poor sanitation

Lack of new antibiotics being developed

Definition of antibiotic resistance

Antibioitc resistance happens when bacteria change and become resistant to the antibiotics used to treat the infections they cause

how to prevent antibiotic resistance

Only use antibiotics when prescribed by a certified health professional

Always take the full prescription, even if you feel better

Never use left over antibiotics

never share antibiotics with others

prevent infections by regularly washing your hands, avoiding contact with sick people and lkeeping your vaccinations up to date