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  • The advent of antibiotics revolutionized the means by which infectious diseases were treated.  Suddenly, common infections became easily curable and outbreaks of infectious disease were readily controlled.   However, the declaration of victory over bacterial pathogens was premature.  Antimicrobial resistance quickly emerged to reduce the clinical usefulness of each new antibiotic that was developed.  Mitigation of antimicrobial resistance is therefore necessary, and requires that veterinarians and other health professionals understand antibiotic sensitivity and resistance at the population, organism, cellular and molecular levels.
  • An antimicrobial is any substance of natural, semisynthetic or synthetic origin that kills or inhibits the growth of microorganisms while hopefully causing minimal damage to the host.  Antimicrobials can be used as therapy for bacteria (antibacterial), viruses (antiviral), fungi (antifungal) or protozoa (antiprotozoal).  The term antibiotic, however, refers to antimicrobials produced by another living microorganism.  Sulfa drugs and other synthetic antimicrobials are not classified as antibiotics, in the strictest sense of the word.
  • Antibiotics may be as classified as either broad spectrum or narrow spectrum depending on how many types of microorganism are naturally susceptible to its action; and bactericidal or bacteriostatic depending on whether the antibiotic kills or inhibits the growth of the target bacteria. Antibiotics may also be classified according to their specific targets and modes of action in that they can be inhibitors of cell wall synthesis, cell membrane function, protein synthesis, nucleic acid synthesis or other metabolic processes.
  • Antibiotics may be used therapeutically in animals for treating bacterial diseases, but they may also be utilized for non-therapeutic purposes such as growth promotion, prophylaxis and metaphylaxis.
  • On a per-weight basis, large amounts of antibiotics are used for animal agriculture.  It is a major public health responsibility of veterinarians to advocate the prudent and judicious use of antibiotics to preserve their future usefulness in treating both animals and people.



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