Editing Tetracycline (section)

==Medical uses==

=== Spectrum of activity ===
Tetracyclines have a broad spectrum of antibiotic action. Originally, they possessed some level of bacteriostatic activity against almost all medically relevant [[Aerobic bacteria|aerobic]] and [[Anaerobic bacteria|anaerobic]] bacterial genera, both [[Gram-positive bacteria|Gram-positive]] and [[Gram-negative bacteria|Gram-negative]], with a few exceptions, such as ''[[Pseudomonas aeruginosa]]'' and [[Proteus (bacterium)|''Proteus'' spp.]], which display intrinsic resistance. However, acquired (as opposed to inherent) resistance has proliferated in many [[pathogenic organisms]] and greatly eroded the formerly vast versatility of this group of antibiotics. Resistance amongst [[Staphylococcus|''Staphylococcus'' spp.]], [[Streptococcus|''Streptococcus'' spp.]], ''[[Neisseria gonorrhoeae]]'', anaerobes, members of the [[Enterobacteriaceae]], and several other previously sensitive organisms is now quite common. Tetracyclines remain especially useful in the management of infections by certain obligately intracellular bacterial pathogens such as ''[[Chlamydia (genus)|Chlamydia]]'', ''[[Mycoplasma]]'', and ''[[Rickettsia]]''. They are also of value in [[Spirochete|spirochaetal]] infections, such as [[syphilis]], and [[Lyme disease]]. Certain rare or exotic infections, including [[anthrax]], [[Plague (disease)|plague]], and [[brucellosis]], are also susceptible to tetracyclines. Tetracycline tablets were used in the plague outbreak in India in 1994.<ref>Lippincott's Illustrated Reviews: Pharmacology, 4th ed. Harvery RA, Champe, PC. Lippincott, Williams & Wilkins, 2009</ref>  Tetracycline is first-line therapy for [[Rocky Mountain spotted fever]] (''Rickettsia''), [[Lyme disease]] (''B. burgdorferi''), [[Q fever]] (''Coxiella''), [[psittacosis]], ''[[Mycoplasma pneumoniae]]'', and nasal carriage of [[Neisseria meningitidis|meningococci]].{{cn|date=March 2023}}

It is also one of a group of antibiotics which together may be used to treat [[Peptic ulcer#H. pylori 2|peptic ulcers]] caused by bacterial infections. The mechanism of action for the antibacterial effect of tetracyclines relies on disrupting protein translation in bacteria, thereby damaging the ability of microbes to grow and repair; however, protein translation is also disrupted in eukaryotic [[mitochondria]] leading to effects that may [[confound]] experimental results.<ref name="pmid25772356">{{Cite journal |vauthors=Moullan N, Mouchiroud L, Wang X, Ryu D, Williams EG, Mottis A, Jovaisaite V, Frochaux MV, Quiros PM, Deplancke B, Houtkooper RH, Auwerx J |date=March 2015 |title=Tetracyclines Disturb Mitochondrial Function across Eukaryotic Models: A Call for Caution in Biomedical Research |journal=Cell Reports |volume=10 |issue=10 |pages=1681–1691 |doi=10.1016/j.celrep.2015.02.034 |pmc=4565776 |pmid=25772356}}</ref><ref name="pmid26475870">{{Cite journal |vauthors=Chatzispyrou IA, Held NM, Mouchiroud L, Auwerx J, Houtkooper RH |date=November 2015 |title=Tetracycline antibiotics impair mitochondrial function and its experimental use confounds research |journal=Cancer Research |volume=75 |issue=21 |pages=4446–4449 |doi=10.1158/0008-5472.CAN-15-1626 |pmc=4631686 |pmid=26475870}}</ref>

The following list presents [[Minimum inhibitory concentration|MIC]] susceptibility data for some medically significant microorganisms:
* ''[[Escherichia coli]]:'' 1 {{abbr|μg|microgram}}/{{abbr|mL|mililiter}} to >128 μg/mL
* ''[[Shigella]]'' {{abbr|spp.|subspecies}}: 1 μg/mL to 128 μg/mL<ref>{{Cite web |date=8 September 2015 |title=Tetracycline hydrochloride |url=http://www.toku-e.com/Assets/MIC/Tetracycline%20hydrochloride.pdf |archive-url=https://web.archive.org/web/20150908102809/http://www.toku-e.com/Assets/MIC/Tetracycline%20hydrochloride.pdf |archive-date=8 September 2015 |website=Susceptibility and Minimum Inhibitory Concentration (MIC) Data |publisher=TOKU-E}}</ref>

===Anti-eukaryote use===
The tetracyclines also have activity against certain [[Eukaryota|eukaryotic]] parasites, including those responsible for diseases such as [[Amoebic dysentery|dysentery]] caused by an [[amoeba]], [[malaria]] (a [[plasmodium]]), and [[balantidiasis]] (a [[ciliate]]).{{cn|date=March 2023}}

===Use as a biomarker===
[[File:Tetracycline-HCl substance photo.jpg|thumb|Tetracycline hydrochloride is available as yellow crystalline powder.]]
Since tetracycline is absorbed into bone, it is used as a marker of bone growth for [[biopsies]] in humans. Tetracycline labeling is used to determine the amount of bone growth within a certain period of time, usually a period around 21 days. Tetracycline is incorporated into mineralizing bone and can be detected by its [[fluorescence]].<ref name="mayton">{{Cite web |title=Tetracycline labeling of bone |url=http://www.histosearch.com/histonet/Dec02/TetracyclinelabelingofbonA.html |archive-url=https://web.archive.org/web/20070312193518/http://www.histosearch.com/histonet/Dec02/TetracyclinelabelingofbonA.html |archive-date=12 March 2007 |vauthors=Mayton CA}}</ref> In "double tetracycline labeling", a second dose is given 11–14 days after the first dose, and the amount of bone formed during that interval can be calculated by measuring the distance between the two fluorescent labels.<ref>{{Cite web |date=8 January 2001 |title=Tetracycline Labeling |url=http://pathology2.jhu.edu/bonelab/4cycline.htm |archive-url=https://archive.today/20121215013608/http://pathology2.jhu.edu/bonelab/4cycline.htm |archive-date=15 December 2012 |website=The Johns Hopkins Medical Institutions.}}</ref>

Tetracycline is also used as a biomarker in [[wildlife]] to detect consumption of medicine- or [[vaccine]]-containing baits.<ref>{{Cite journal |vauthors=Olson CA, Mitchell KD, Werner PA |date=October 2000 |title=Bait ingestion by free-ranging raccoons and nontarget species in an oral rabies vaccine field trial in Florida |url=http://www.jwildlifedis.org/cgi/reprint/36/4/734 |url-status=dead |journal=Journal of Wildlife Diseases |volume=36 |issue=4 |pages=734–743 |doi=10.7589/0090-3558-36.4.734 |pmid=11085436 |s2cid=35102508 |archive-url=https://archive.today/20130415041932/http://www.jwildlifedis.org/cgi/reprint/36/4/734 |archive-date=15 April 2013}}</ref>