Bacteriophages

Question 1

New pproaches to antimicrobial therapy can include bacteriophages

Answer 1

Eastern European countries use mixtures of bacteriophages as medicine, but these drugs have never been approved for use in the West.
Biophage-PA used to treat ear infections caused by Pseudomonas aeruginosa biofilms
Other researchers are incorporating bacteriophages into wound dressings.
Advantage to bacteriophage is their narrow specificity; only infect one species of bacterium

Question 2

Probiotics:

Answer 2

Preparations of live microorganisms fed to animals and humans to improve intestinal biota
Can replace microbes lost during antimicrobial therapy
Augment biota already there
Safe and effective
Useful in the management of food allergies

Question 3

Prebiotics:

Answer 3

Nutrients that encourage the growth of beneficial microbes

Fructans encourage the growth of Bifidobacterium in the large intestine and discourage the growth of pathogens.

Question 4

Fecal transplants:

Answer 4

Used to treat recurrent Clostridium difficile infection and ulcerative colitis.
Transfer of feces from a healthy patient via colonoscopy
Work is underway to develop a pill containing the species to re-colonize the colon.

Question 5

Drug is administered to the host even though its target is a microbe. The effect of the drug on the host must be considered.
What is ideal, what does chemotherapy involve?
How many people may face adverse effects?

Answer 5

Drug is administered to the host even though its target is a microbe. The effect of the drug on the host must be considered.
Selective toxicity is the ideal, but chemotherapy involves contact with foreign chemicals that can harm the host:
Five percent of all persons taking an antimicrobial drug will experience an adverse side effect.

Question 6

Drugs can adversely affect the following organs:

Answer 6

Liver (hepatotoxic)
Kidneys (nephrotoxic)
Gastrointestinal tract
Cardiovascular system and blood forming tissue (hemotoxic)
Nervous system (neurotoxic)
Respiratory tract
Skin
Bones and teeth

Question 7

What is an allergy? Provoked by? Sesitization? Second exposure?

Answer 7

Heightened sensitivity to a drug
Drug acts as an antigen that stimulates the allergic response
Can be provoked by the intact molecule or by substances that develop from the metabolic alteration of the drug
Allergies have been reported for every major type of drug, but allergy to penicillins is most common.
Sensitization occurs during the first contact with the drug.
Second exposure can lead to hives, respiratory inflammation, or anaphylaxis.

Question 8

Describe a healthy human biota

Answer 8

Normal microbial colonists of healthy body surfaces
Normally consist of harmless or beneficial bacteria
A few may be pathogens
Broad-spectrum antimicrobials destroy healthy biota along with pathogens.

Question 9

What is a superinfection?

Answer 9

microbes that were once small in number overgrow when normal resident biota are destroyed by broad-spectrum antimicrobials

Question 10

Examples of superinfeaction include

Answer 10

Urinary tract infection caused by E. coli treated with antibiotics:
Lactobacilli in the female vagina are killed by the broad-spectrum cephalosporin used to treat the UTI.
Overgrowth of Candida albicans occurs, causing a vaginal yeast infection or oral thrush.

Antibiotic-associated colitis:
Oral therapy with tetracyclines, clindamycin, and broad-spectrum penicillins kills off normal biota of the colon.
Overgrowth of Clostridium difficile invades the intestinal lining and releases toxins that cause diarrhea, fever, and abdominal pain.