A narrow-
spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors ...
antibiotic is an
antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...
that is only able to kill or inhibit limited species of bacteria.
Examples of narrow-spectrum antibiotics include
fidaxomicin and
sarecycline
Sarecycline is a narrow-spectrum tetracycline-derived antibiotic. It is specifically designed for the treatment of acne, and was approved by the FDA in October 2018 for the treatment of inflammatory lesions of non-nodular moderate to severe acne ...
.
Advantages
* Narrow-spectrum antibiotic allow to kill or inhibit only those bacteria species that are unwanted (i.e. causing disease). As such, it leaves most of the beneficial bacteria unaffected, hence minimizing the collateral damage on the
microbiota
Microbiota are the range of microorganisms that may be commensal, symbiotic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been found ...
.
*Low propensity for
bacterial resistance development.
Disadvantages
Often, the exact species of bacteria causing the illness is unknown, in which case narrow-spectrum antibiotics can't be used, and broad-spectrum antibiotics are used instead. To know the exact species of bacteria causing the illness, clinical specimens need to be taken for antimicrobial susceptibility testing in a
clinical microbiology
Medical microbiology, the large subset of microbiology that is applied to medicine, is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies vario ...
laboratory.
See also
*
Broad-spectrum antibiotic
A broad-spectrum antibiotic is an antibiotic that acts on the two major bacterial groups, Gram-positive and Gram-negative, or any antibiotic that acts against a wide range of disease-causing bacteria. These medications are used when a bacterial ...
s
References
Further reading
Repurposing CRISPR-Cas systems as DNA-based smart antimicrobials
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Antibiotics