broad spectrum antibiotic

(noun)

A type of antibiotic that can affect a wide range of bacteria.

Related Terms

Examples of broad spectrum antibiotic in the following topics:

  • Spectrum of Antimicrobial Activity

    • The range of bacteria that an antibiotic affects can be divided into narrow spectrum and broad spectrum.
    • Broad spectrum—antibiotics act against gram positive and gram negative bacteria, for example amoxicillin.
    • A broad spectrum antibiotic acts against both Gram-positive and Gram-negative bacteria, in contrast to a narrow spectrum antibiotic, which is effective against specific families of bacteria.
    • An example of a commonly used broad-spectrum antibiotic is ampicillin.
    • Broad spectrum antibiotics are also used for drug resistant bacteria that do not respond to other, more narrow spectrum antibiotics and in the case of superinfections, where there are multiple types of bacteria causing illness, thus warranting either a broad-spectrum antibiotic or combination antibiotic therapy.

  • Organ Toxicity

    • Use of some antibiotics, such as gentamicin, can cause a lose of hearing, or tinnitus ("ringing in the ears").
    • Ototoxicity is usually temporary with antibiotics, but permanent hearing damage, while rare, has been reported.
    • Broad-spectrum antibiotics in the family of fluoroquinolones can cause neurotoxicity by directly damaging neuronal receptors.
    • However, it should be noted that the side-effects due to broad-spectrum antibiotics are actually quite rare, with organ damage being even more rare.The potential side-effects of antibiotics or other antimicrobial drugs are offset by the benefits of combating the microbial infection.
    • This rash seen on a forearm is a typical reaction observed when an antibiotic causes phototoxicity.

  • Antibiotic Classifications

    • Bactericidal antibiotics kill bacteria; bacteriostatic antibiotics slow their growth or reproduction.
    • Antibiotics can be divided into two classes based on their mechanism of action.
    • Bactericidal antibiotics kill bacteria; bacteriostatic antibiotics inhibit their growth or reproduction.
    • However, there is not always a precise distinction between them and bactericidal antibiotics.
    • "Narrow-spectrum" antibacterial antibiotics target specific types of bacteria, such as Gram-negative or Gram-positive bacteria, whereas broad-spectrum antibiotics affect a wide range of bacteria, usually both gram positive and gram negative cells.

  • Nongonococcal Urethritis (NGU)

    • Since many different infectious agents can be causing NGU, the initial treatment should be with a broad spectrum antibiotic.
    • The structure of azithromycin, a microlide antibiotic used to treat NGU.

  • Antibiotics and Selective Toxicity

    • Antibiotics are able to selectively target specific types of bacteria without harming the infected host.
    • Antibiotics are commonly classified based on their mechanism of action, chemical structure, or spectrum of activity.
    • More specifically, narrow spectrum antibiotics target specific types of bacteria, such as Gram-negative or Gram-positive bacteria, whereas broad spectrum antibiotics affect a wide range of bacteria.
    • Useful antibiotics are often discovered using a screening process.
    • Most antibiotics identified in such a screen are already known and must therefore be disregarded.

  • Kirby-Bauer Disk Susceptibility Test

    • Kirby-Bauer antibiotic testing (also called KB testing or disk diffusion antibiotic sensitivity testing) uses antibiotic-containing wafers or disks to test whether particular bacteria are susceptible to specific antibiotics.
    • A larger zone of inhibition around an antibiotic-containing disk indicates that the bacteria are more sensitive to the antibiotic in the disk.
    • Clinicians can use KB test results to choose appropriate antibiotics to combat a particular infection in a patient.
    • Administering antibiotics that specifically target the particular bacteria that are causing the infection can avoid using broad-spectrum antibiotics, which target many types of bacteria.
    • In Kirby–Bauer testing, discs containing antibiotics are placed on agar where bacteria are growing, and the antibiotics diffuse out into the agar.

  • Minimal Inhibitory Concentration (MIC)

    • In microbiology, minimum inhibitory concentration (MIC) is the lowest concentration of an antimicrobial (like an antifungal, antibiotic or bacteriostatic) drug that will inhibit the visible growth of a microorganism after overnight incubation.
    • The minimum inhibitory concentration of the antibiotic is between the concentrations of the last well in which no bacteria grew and the next lower dose, which allowed bacterial growth.
    • Clinicians use MIC scores to choose which antibiotics to administer to patients with specific infections and to identify an effective dose of antibiotic.
    • This is important because populations of bacteria exposed to an insufficient concentration of a particular drug or to a broad-spectrum antibiotic (one designed to inhibit many strains of bacteria) can evolve resistance to these drugs.
    • To identify the lowest concentration required for a given antibiotic to inhibit bacterial growth, an identical amount of bacteria is introduced into wells of liquid media containing progressively lower concentrations of the drug.

  • Damage to Proteins and Nucleic Acids

    • Depending on their application, bacteriostatic antibiotics, disinfectants, antiseptics, and preservatives can be distinguished.
    • Bacteriostatic antibiotics limit the growth of bacteria by interfering with bacterial protein production, DNA replication, or other aspects of bacterial cellular metabolism.
    • However, there is not always a precise distinction between them and bactericidal antibiotics.
    • Tetracycline is a broad-spectrum polyketide antibiotic produced by the Streptomyces genus of Actinobacteria, indicated for use against many bacterial infections.
    • It is also used to produce several semisynthetic derivatives, which together are known as the tetracycline antibiotics.

  • Suppression and Alteration of Microbiota by Antimicrobials

    • This is especially a problem when broad-spectrum antimicrobial agents are used, as antimicrobial treatments while helping to clear up pathogenic microbes from the body will often kill symbiotic bacteria.
    • The treatment of translocated or pathogenic bacteria may necessitate the use of antibiotics that will kill symbiotic bacteria.
    • C. albicans is normally harmless, but when women take some antibiotics this can kill beneficial bacteria, specifically lactobacilli, in the vulvo-vaginal area.
    • Fortunately there are antimicrobial agents that specifically target pathogenic bacterial species, which opposed to broad-spectrum treatments can reduce harmful effects on beneficial microbes.
    • Sometimes the use of broad-spectrum antimicrobial agents is unavoidable; in these situations, consuming foods such as yogurt which contains beneficial bacteria can replenish the body's symbiotic microbes.

  • Antimicrobial Peptides

    • In contrast to the clonal, acquired adaptive immunity, endogenous peptide antibiotics or antimicrobial peptides provide a fast and energy-effective mechanism as front-line defense.
    • Antimicrobial peptides (AMPs) are small molecular weight proteins with broad spectrum antimicrobial activity against bacteria, viruses, and fungi.
    • These peptides qualify as innovative drugs that might be used as antibiotics, anti-lipopolysaccharide drugs, or modifiers of inflammation reactions.