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Testing the susceptibility of Staphylococcus aureus to antibiotics by the KirbyBauer disk
diffusion method. Antibiotics diffuse out from antibioticcontaining disks and inhibit growth of S.
aureus resulting in a zone of inhibition.
In modern usage, an antibiotic is a chemotherapeutic agent with activity against microorganisms
such as bacteria, fungi…

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antibiotic. Some antibacterial antibiotics destroy bacteria (bactericidal), whereas others prevent
bacteria from multiplying (bacteriostatic).
Oral antibiotics are simply ingested, while intravenous antibiotics are used in more serious cases,
such as deepseated systemic infections. Antibiotics may also sometimes be administered
topically, as with eye drops or ointments.
In the last few…

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Points of attack on bacteria by antibiotics
At the highest level, antibiotics can be classified as either bactericidal or bacteriostatic.
Bactericidals kill bacteria directly where bacteriostatics prevent cell division. However, these
classifications are based on laboratory behavior in practice, both of these are capable of ending
a bacterial infection.[2] The…

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reactions including photodermatitis.[citation needed] One of the more common side effects is
diarrhea, sometimes caused by the anaerobic bacterium Clostridium difficile, which results
from the antibiotic disrupting the normal balance of the intestinal flora,[8] Such overgrowth of
pathogenic bacteria may be alleviated by ingesting probiotics during a course of

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Microbiology (ASM), American Public Health Association (APHA) and the American Medical
Association (AMA)) have called for restrictions on antibiotic use in food animal production and
an end to all nontherapeutic uses.[citation needed] However, delays in regulatory and legislative
actions to limit the use of antibiotics are common, and may include…

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resistance which may result in coresistance to multiple antibiotics.[28][31] These plasmids can
carry different genes with diverse resistance mechanisms to unrelated antibiotics but because
they are located on the same plasmid multiple antibiotic resistance to more than one antibiotic is
transferred.[31] Alternatively, crossresistance to other antibiotics within the bacteria results…

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Bacteriocins are also a growing alternative to the classic smallmolecule antibiotics [34]. Different
classes of bacteriocins have different potential as therapeutic agents. Small molecule
bacteriocins (microcins, for example, and lantibiotics) may be similar to the classic antibiotics
colicinlike bacteriocins are more likely to be narrowspectrum, demanding new molecular
diagnostics prior…


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