Transcript Antibacterials! - Littleton High School

Antibacterials!
By, Becky Luoma
Definition:
• Antibacterials are chemicals, which prevent the
growth and multiplication of bacteria
Infectious Organisms
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The types of micro-organisms that can cause different types of diseases are:
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The most typical bacterium are made of:
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They will most likely be found inside of the body
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Bowel
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Stomach
There are a lot of bacteria that are actually beneficial to the body and do not cause disease
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They will most likely be found infecting surface areas
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Skin
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Respiratory tract
Anaerobic bacterium are much more dangerous because they need either either very little oxygen or no oxygen at all
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A single cell
Protective wall
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Proteins
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Sugars
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Lipids
Cytoplasm
Granules of glycogen
Lipids
Other food reserves
Each cell has a single chromosome that consists of a deoxyribonucleic acid (DNA) strand
Some may have flagellum
There are some aerobic bacterium that require oxygen to thrive
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Bacteria
Viruses
Fungi
Yeasts
Protozoa
Some exist in or on the body but don’t do anything at all
Some cannot even live in or one the body
The average size of a bacterium is 0.001mm wide
Narrow and Broad Spectrum
Antibiotics:
• Narrow antibiotics can only fight against certain types of bacteria
▫ All penecillins are narrow antiobiotics
• Broad spectrum antibiotics are effective when used against many
different types of bacteria
▫ Tetracyclines
 Aureomycin
 Terramycin
• To determine what antibiotics must be given to the patient, blood,
sputum (mucus), urine, pus, or stool samples must be taken
▫ Because this takes time to do, broad spectrum antibiotics are generally
prescribed at first
 Once the bacteria that is infecting the body is known, it may be switched to
a narrow spectrum antibiotic to target a specific bacterium
Mechanism of Action of Antibiotics:
• Two main mechanisms to destroy bacteria that
antibiotics use
▫ Penicillins and the cephalosporins don’t allow from
bacteria to make normal cell walls
 It does this by inactivating an enzyme necessary for the
cross linking of bacterial cell walls. The enzyme is known
as transpeptidase. It accepts the penicillin as a substrate
into the active site and then makes the enzyme
completely inactive and deteriorates the cell wall
▫ Other antibiotics go inside of the bacteria and interfere
with the chemical activities that must be taken out to
sustain their life
 Can prohibit the bacteria from turning glucose into
energy
Discovery of Penicillin:
• The first antibacterial that worked was called dye trypan red
and was created by Paul Ehrlich as a cure for sleeping sickness
▫ Sleeping sickness is caused by the bite of a tsetse fly in Africa
where it inserts trypanosomes
 The cure contained an arsenic compound (salvarsan) which is
effective against syphilis
• The first ‘sulfa duh’ prontosil was created which is effective
against streptococcal bacteria (strep)
• Alexander Fleming left a Petri dish containing one of the
culture in the laboratory when he went on a holiday
▫ Mold had developed on the cultures, and he realized that the
growth of the bacterium had been stopped
 The mold inhibited the growth of bacteria
 Called Penicillin
Discovery of Penicillin (continued):
• Even though Fleming found this, he did not
pursue this amazing discovery
▫ Howard Florey and Ernest Chain isolated and
purified penicillin after Fleming found it
 Tried to use on a police man who had septicaemia
 Not enough penicillin because it was only grown in
Petri dishes
▫ Police man died, but then penicillin started to be made in
bulk
Penicillin
• Now, penicillin is produced in bulk because it
took a very long time to make a supple amount
of it from Petri dishes
▫ Grown in large tanks containing corn-steep liquor
▫ Different types of penicillin and antibiotics can be
made in laboratories because the structure was
determined
Penecillin’s structure: (polar)
Overuse and Resistance to Penicillins
• Penicillinase allows for certain bacteria to be
resistant to the penicillin so that they can multiply
▫ Can deactivate penicillin G (the original penicillin)
▫ So chemists have made it so that other penicillins can
keep the active part of these bacteria the same, but
completely morph their side chain so that they can’t
carry out their actions and so that they are more
resistant to the penicillinase
 Bacteria multiply and mutate too fast, so antibiotics and
medicines that are completely effective are hard to come
by and are even more resistant breeds
 Called ‘super bugs’
Overuse and Resistance to Penicillins
(continued):
• Antibiotics are given to animals in feedstocks so
that they are less likely to get certain bacterium
that are common there (even healthy ones are
given them!!)
▫ The antibiotics are passed through meats and
dairy products to humans
 Many problems with this:
 Too many antibiotics is not good for the body
 Increases the development of resistant bacteria in the
body
▫ Creates even more ‘super bugs’
▫ Hurts more than in helps!
Differences between Penicillins (and
Cephalosporins) and Sulfa Drugs
• Sulfa drugs:
▫ Stop bacteria from growing
 However, they do not kill the
bacteria
▫ The first antibiotics created
▫ Completely manmade and
natural
▫ Have many different effects on
the people using them
 More common to have
problems than in Penicillins
 Taken with another drug
(erythromycin or
trimethropin)
 More allergic reactions
 Some even life-threatening
• Penicillins:
▫ Kill the bacteria by removing
the cell wall
▫ Less common to have allergies
 But more severe when had
 Diarrhea
 Rashes
 Hives
 Anaphylactic shock
▫ Airways swell up to the
point of not being able to
breathe
▫ Epinephrine must be
administered if this
happens
▫ Which we just learned
is actually adrenaline 
Patient Compliance:
• Because so many different drugs are being used
to treat many infections, the patient must
comply
▫ The number of allergies and responses to
antibiotics is so high that death could possibly
occur
• Resistance problems (caused by the feedstocks
as previously talked about)
Citations:
• http://www.chm.bris.ac.uk/webprojects2002/th
ornton/how_does_penicillin_work.htm
• http://health.howstuffworks.com/healthillness/treatment/medicine/medications/questi
on88.htm
• http://www.drreddy.com/antibx.html#sulfa
• http://www.detectingdesign.com/images/Antibi
otics_Viruses/lactam1.jpg
• http://www.uen.org/utahlink/activities/view_a
ctivity.cgi?activity_id=3023