Editing Broad-spectrum antibiotic

{{Short description|Treatment for a wide range of bacteria}}
[[File:Neutrophil MRSA II.jpg|thumb|A colored electron microscopy image of methicillin-resistant staphylococcus aureus ([[Methicillin-resistant Staphylococcus aureus|MRSA]]), a bacterium commonly targeted by broad-spectrum antibiotics]]
A '''broad-[[antimicrobial spectrum|spectrum]] antibiotic''' is an [[antibiotic]] that acts on the two major bacterial groups, [[Gram-positive]] and [[Gram-negative]],<ref>{{cite journal | vauthors = Ory EM, Yow EM | title = The use and abuse of the broad spectrum antibiotics | journal = JAMA | volume = 185 | issue = 4 | pages = 273–9 | date = July 1963 | pmid = 13940450 | doi = 10.1001/jama.1963.03060040057022 }}</ref> or any antibiotic that acts against a wide range of disease-causing [[bacteria]].<ref>{{cite book |editor=Clayton L. Thomas |year=1993 |title=Taber's Cyclopedic Medical Dictionary |edition=17th |isbn=978-0-8036-8313-6 |publisher=F.&nbsp;A. Davis Co.}}</ref> These medications are used when a bacterial infection is suspected but the group of bacteria is unknown (also called [[empiric therapy]]) or when infection with multiple groups of bacteria is suspected. This is in contrast to a [[narrow-spectrum antibiotic]], which is effective against only a specific group of [[bacteria]].<ref name="Hopkins">{{cite book | vauthors = Hopkins SJ |year=1997 |title=Drugs and Pharmacology for Nurses |edition=12th |isbn=978-0-443-05249-1 |publisher=Churchill Livingstone}}</ref> Although powerful, broad-spectrum antibiotics pose specific risks, particularly the disruption of native, normal bacteria and the development of [[antimicrobial resistance]]. An example of a commonly used broad-spectrum antibiotic is [[ampicillin]].<ref name="Hopkins"/>

== Bacterial targets ==
Antibiotics are often grouped by their ability to act on different bacterial groups. Although bacteria are biologically classified using [[Bacterial taxonomy|taxonomy]], disease-causing bacteria have historically been classified by their microscopic appearance and chemical function. The morphology of the organism may be classified as [[Coccus|cocci]], [[Diplococcus|diplococci]], [[bacilli]] (also known as "rods"), spiral-shaped or pleomorphic. Additional classification occurs through the organism's ability to take up the [[Gram stain|Gram stain and counter-stain]]; bacteria that take up the crystal violet dye stain are referred to as "gram-positive," those that take up the counterstain only are "gram-negative," and those that remain unstained are referred to as "atypical."  Further classification includes their requirement for oxygen (i.e., aerobic or anaerobic), [[Hemolysis (microbiology)|patterns of hemolysis]], or other chemical properties. The most commonly encountered groupings of bacteria include gram-positive cocci, gram-negative bacilli, atypical bacteria, and anaerobic bacteria.<ref name=":1">{{Cite book|title=Harrison's principles of internal medicine. |isbn=9780071802154|edition=19th |location=New York|oclc=893557976|last1 = Kasper|first1 = Dennis L.|last2=Larry Jameson|first2=J.|last3=Hauser|first3=Stephen L.|last4=Loscalzo|first4=Joseph|last5=Fauci|first5=Anthony S.|last6=Longo|first6=Dan L. | name-list-style = vanc |date=2015-04-08}}</ref>

== Empiric antibiotic therapy ==
{{Main|Empiric therapy}}
[[File:Antibiotic chart.svg|thumb|395x395px|Simplified diagram showing common disease-causing bacteria and the antibiotics which act against them.]]
Empiric antibiotic therapy refers to the use of antibiotics to treat a suspected bacterial infection despite lack of a specific bacterial diagnosis. Definitive diagnosis of the species of bacteria often occurs through [[Growth medium|culture]] of blood, sputum, or urine, and can be delayed by 24 to 72 hours.<ref name=":0">{{cite journal | vauthors = Leekha S, Terrell CL, Edson RS | title = General principles of antimicrobial therapy | journal = Mayo Clinic Proceedings | volume = 86 | issue = 2 | pages = 156–67 | date = February 2011 | pmid = 21282489 | pmc = 3031442 | doi = 10.4065/mcp.2010.0639 }}</ref> Antibiotics are generally given ''after'' the culture specimen has been taken from the patient in order to preserve the bacteria in the specimen and ensure accurate diagnosis.<ref name=":1" /> Alternatively, some species may be identified through a urine or stool test.<ref name=":1" />

== Risks ==

=== Disruption of normal  microbiome ===
{{See also|Antibiotic misuse}}
There are an estimated 38 trillion microorganisms that colonize the human body.<ref>{{cite journal | vauthors = Sender R, Fuchs S, Milo R | title = Revised Estimates for the Number of Human and Bacteria Cells in the Body | journal = PLOS Biology | volume = 14 | issue = 8 | pages = e1002533 | date = 2016 | pmid = 27541692 | pmc = 4991899 | doi = 10.1371/journal.pbio.1002533 | doi-access = free }}</ref> As a side-effect of therapy, antibiotics can change the body's normal [[microbiota|microbial content]] by attacking indiscriminately both the pathological and naturally occurring, beneficial or harmless bacteria found in the intestines, lungs and bladder.<ref name="Martin">{{cite book | vauthors = Martin EA |year=2003 |title=Oxford Concise Medical Dictionary |edition=6th |isbn=978-0-19-860753-3 |publisher=Oxford University Press}}</ref> The destruction of the body's normal bacterial [[flora]] is thought to disrupt immunity, nutrition, and lead to a relative overgrowth in some bacteria or fungi.<ref>{{cite journal | vauthors = Rafii F, Sutherland JB, Cerniglia CE | title = Effects of treatment with antimicrobial agents on the human colonic microflora | journal = Therapeutics and Clinical Risk Management | volume = 4 | issue = 6 | pages = 1343–58 | date = December 2008 | pmid = 19337440 | pmc = 2643114 | doi = 10.2147/tcrm.s4328 | doi-access = free }}</ref> An overgrowth of drug-resistant microorganisms can lead to a secondary infection such as ''[[Clostridioides difficile (bacteria)|Clostridioides difficile]]'' ("C. diff") or [[candidiasis]] ("thrush").<ref name="Hopkins" /> This side-effect is more likely with the use of broad-spectrum antibiotics, given their greater potential to disrupt a larger variety of normal human flora.<ref name="Martin" /> The use of [[doxycycline]] in [[acne vulgaris]] has been associated with increased risk of [[Crohn's disease]],<ref>{{Cite journal|last1=Margolis|first1=David J.|last2=Fanelli|first2=Matthew|last3=Hoffstad|first3=Ole|last4=Lewis|first4=James D.|date=2010|title=Potential association between the oral tetracycline class of antimicrobials used to treat acne and inflammatory bowel disease|url=https://pubmed.ncbi.nlm.nih.gov/20700115/|journal=The American Journal of Gastroenterology|volume=105|issue=12|pages=2610–2616|doi=10.1038/ajg.2010.303|issn=1572-0241|pmid=20700115|s2cid=20085592}}</ref> although a later study indicated a link between [[acne vulgaris]] and [[Irritable bowel syndrome|IBS]] irrespective of the use of antibiotics.<ref>{{Cite journal |last1=Taylor |first1=Matthew T. |last2=Margolis |first2=David J. |last3=Kwatra |first3=Shawn G. |last4=Barbieri |first4=John S. |date=April 2023 |title=A propensity score matched cohort study identifying an association of acne, but not oral antibiotic or isotretinoin use, with risk of incident inflammatory bowel disease |journal=Journal of the American Academy of Dermatology |volume=88 |issue=4 |pages=841–847 |doi=10.1016/j.jaad.2023.01.014 |issn=1097-6787 |pmid=36682724|pmc=10033360 }}</ref> Likewise, the use of [[minocycline]] in acne vulgaris has been associated with skin and gut dysbiosis.<ref>{{Cite journal|last1=Thompson|first1=Katherine G.|last2=Rainer|first2=Barbara M.|last3=Antonescu|first3=Corina|last4=Florea|first4=Liliana|last5=Mongodin|first5=Emmanuel F.|last6=Kang|first6=Sewon|last7=Chien|first7=Anna L.|date=2020-02-01|title=Minocycline and Its Impact on Microbial Dysbiosis in the Skin and Gastrointestinal Tract of Acne Patients|journal=Annals of Dermatology|language=en|volume=32|issue=1|pages=21–30|doi=10.5021/ad.2020.32.1.21 |pmid=33911705| pmc=7992645 |issn=1013-9087|doi-access=free}}</ref>

== Examples of broad-spectrum antibiotics ==
In [[humans]]:{{cn|date=February 2023}}
* [[Doxycycline]]
* [[Minocycline]]
* [[Aminoglycosides]] (except for [[streptomycin]])
* [[Ampicillin]]
* [[Amoxicillin/clavulanic acid]] (Augmentin)<ref>{{cite journal | vauthors = Coon ER, Quinonez RA, Morgan DJ, Dhruva SS, Ho T, Money N, Schroeder AR | title = 2018 Update on Pediatric Medical Overuse: A Review | journal = JAMA Pediatrics | volume = 173 | issue = 4 | pages = 379–384 | date = April 2019 | pmid = 30776069 | doi = 10.1001/jamapediatrics.2018.5550 | s2cid = 73495617 }}</ref>
* [[Azithromycin]]<ref>{{cite journal | vauthors = McMullan BJ, Mostaghim M | title = Prescribing azithromycin | journal = Australian Prescriber | volume = 38 | issue = 3 | pages = 87–9 | date = June 2015 | pmid = 26648627 | pmc = 4653965 | doi = 10.18773/austprescr.2015.030 }}</ref>
* [[Carbapenems]] (e.g. [[imipenem]])
* [[Piperacillin/tazobactam]]
* [[Quinolone antibiotic|Quinolones]] (e.g. [[ciprofloxacin]])
* [[Tetracycline antibiotics|Tetracycline-class drugs]] (except [[sarecycline]])
* [[Chloramphenicol]]
* [[Ticarcillin]]

* [[Trimethoprim/sulfamethoxazole]] (Bactrim)
* [[Ofloxacin]]
In [[veterinary medicine]], [[co-amoxiclav]], (in small animals); [[penicillin]] & [[streptomycin]] and [[oxytetracycline]] (in farm animals); [[penicillin]] and [[sulfonamide (medicine)|potentiated sulfonamides]] (in horses).

== References ==
{{reflist}}

[[Category:Antibiotics]]