Editing Staphylococcus aureus (section)

== Role in disease ==
{{Further|Coagulase-positive staphylococcal infection}}
[[File:3D Medical Animation Staphylococcus Aureus.jpg|alt=3D Medical Animation still shot of Osteomyelitis bone|thumb|251x251px|3D medical animation still shot of osteomyelitis bone]]
[[Image:MRSA7820.jpg|thumb|250px|This 2005 [[scanning electron micrograph]] (SEM) depicts numerous clumps of [[Methicillin-resistant S. aureus|methicillin-resistant ''S. aureus'']] (MRSA) bacteria.]]

While ''S. aureus'' usually acts as a [[commensal bacterium]], [[Asymptomatic infection|asymptomatically]] [[Bacterial colony|colonizing]] about 30% of the human population, it can sometimes cause disease.<ref name=Tong2015>{{cite journal | vauthors = Tong SY, Davis JS, Eichenberger E, Holland TL, Fowler VG | title = ''Staphylococcus aureus'' infections: epidemiology, pathophysiology, clinical manifestations, and management | journal = Clinical Microbiology Reviews | volume = 28 | issue = 3 | pages = 603–661 | date = July 2015 | pmid = 26016486 | pmc = 4451395 | doi = 10.1128/CMR.00134-14 }}</ref> In particular, ''S. aureus'' is one of the most common causes of [[bacteremia]] and [[infective endocarditis]]. Additionally, it can cause various [[skin infection|skin]] and [[soft-tissue]] infections,<ref name=Tong2015/> particularly when skin or [[Mucosal immunology|mucosal barriers]] have been breached.

''Staphylococcus aureus'' infections can [[Transmission (medicine)|spread]] through contact with [[pus]] from an infected wound, skin-to-skin contact with an infected person, and contact with objects used by an infected person such as towels, sheets, clothing, or athletic equipment. [[Joint replacement]]s put a person at particular risk of [[septic arthritis]], staphylococcal [[endocarditis]] (infection of the heart valves), and [[pneumonia]].<ref name="pmid15963281">{{cite journal | vauthors = Kuehnert MJ, Hill HA, Kupronis BA, Tokars JI, Solomon SL, Jernigan DB | title = Methicillin-resistant-''Staphylococcus aureus'' hospitalizations, United States | journal = Emerging Infectious Diseases | volume = 11 | issue = 6 | pages = 868–872 | date = June 2005 | pmid = 15963281 | pmc = 3367609 | doi = 10.3201/eid1106.040831 }}</ref>

''Staphylococcus aureus'' is a significant cause of chronic biofilm infections on [[medical implants]], and the [[repressor]] of toxins is part of the infection pathway.<ref name="KavanaughHorswill2016">{{cite journal | vauthors = Kavanaugh JS, Horswill AR | title = Impact of Environmental Cues on Staphylococcal Quorum Sensing and Biofilm Development | journal = The Journal of Biological Chemistry | volume = 291 | issue = 24 | pages = 12556–64 | date = June 2016 | pmid = 27129223 | pmc = 4933443 | doi = 10.1074/jbc.R116.722710 | type = Review | doi-access = free }}</ref>

''Staphylococcus aureus'' can lie dormant in the body for years undetected.  Once symptoms begin to show, the host is contagious for another two weeks, and the overall illness lasts a few weeks. If untreated, though, the disease can be deadly.<ref>{{cite web|url=https://www.cdc.gov/hai/organisms/staph.html|title=''Staphylococcus aureus'' in Healthcare Settings {{!}} HAI|website=CDC|access-date=19 April 2017}}</ref> Deeply penetrating ''S. aureus'' infections can be severe.{{citation needed|date=December 2022}}

=== Skin infections ===
[[List of cutaneous conditions#Bacterium-related|Skin infections]] are the most common form of ''S. aureus'' infection. This can manifest in various ways, including small benign [[boil]]s, [[folliculitis]], [[impetigo]], [[cellulitis]], and more severe, invasive soft-tissue infections.<ref name=medlineplus/><ref name=Tong2015/>

''Staphylococcus aureus'' is extremely prevalent in persons with [[atopic dermatitis]] (AD), more commonly known as eczema.<ref name="Monnot">{{cite journal | vauthors = Monnot GC, Wegrecki M, Cheng TY, Chen YL, Sallee BN, Chakravarthy R, Karantza IM, Tin SY, Khaleel AE, Monga I, Uwakwe LN, Tillman A, Cheng B, Youssef S, Ng SW, Shahine A, Garcia-Vilas JA, Uhlemann AC, Bordone LA, Han A, Rohde CH, Ogg G, Moody DB, Rossjohn J, de Jong A| title = Staphylococcal phosphatidylglycerol antigens activate human T cells via CD1a | journal = Nature Immunology | volume = 24 | issue = 1 | pages = 110–122 | date = January 2023 | pmid = 35265979 | doi = 10.1038/s41590-022-01375-z| s2cid = 255039948 | pmc = 10389259 }}</ref> It is mostly found in fertile, active places, including the armpits, hair, and scalp. Large pimples that appear in those areas may exacerbate the infection if lacerated. Colonization of ''S. aureus'' drives inflammation of AD.<ref>{{cite journal |vauthors=Kobayashi T, Glatz M, Horiuchi K, Kawasaki H, Akiyama H, Kaplan DH, Kong HH, Amagai M, Nagao K |date=April 2015 |title=Dysbiosis and ''Staphylococcus aureus'' Colonization Drives Inflammation in Atopic Dermatitis |journal=Immunity |volume=42 |issue=4 |pages=756–766 |doi=10.1016/j.immuni.2015.03.014 |pmc=4407815 |pmid=25902485}}</ref><ref name="Monnot" /> ''S. aureus'' is believed to exploit defects in the skin barrier of persons with atopic dermatitis, triggering [[cytokine]] expression and therefore exacerbating symptoms.<ref>{{cite journal |vauthors=Nakatsuji T, Chen TH, Two AM, Chun KA, Narala S, Geha RS, Hata TR, Gallo RL |date=November 2016 |title=''Staphylococcus aureus'' Exploits Epidermal Barrier Defects in Atopic Dermatitis to Trigger Cytokine Expression |journal=The Journal of Investigative Dermatology |volume=136 |issue=11 |pages=2192–2200 |doi=10.1016/j.jid.2016.05.127 |pmc=5103312 |pmid=27381887}}</ref> This can lead to [[staphylococcal scalded skin syndrome]], a severe form of which can be seen in [[newborns]].<ref name="Pediatrics1980-Curran">{{cite journal | vauthors = Curran JP, Al-Salihi FL | title = Neonatal staphylococcal scalded skin syndrome: massive outbreak due to an unusual phage type | journal = Pediatrics | volume = 66 | issue = 2 | pages = 285–290 | date = August 1980 | pmid = 6447271 | doi = 10.1542/peds.66.2.285 | s2cid = 21783186 }}</ref>

The role of ''S. aureus'' in causing [[itching]] in atopic dermatitis has been studied.<ref>{{Cite journal |last1=Gallo |first1=Richard L. |last2=Horswill |first2=Alexander R. |date=May 2024 |title=Staphylococcus aureus: The Bug Behind the Itch in Atopic Dermatitis |journal=[[Journal of Investigative Dermatology]] |volume=144 |issue=5 |pages=950–953 |doi=10.1016/j.jid.2024.01.001|pmid=38430083 |doi-access=free }}</ref>

Antibiotics are commonly used to target overgrowth of ''S. aureus'' but their benefit is limited and they increase the risk of [[antimicrobial resistance]]. For these reasons, they are only recommended for people who not only present symptoms on the skin but feel systematically unwell.<ref>{{cite journal | vauthors = George SM, Karanovic S, Harrison DA, Rani A, Birnie AJ, Bath-Hextall FJ, Ravenscroft JC, Williams HC | title = Interventions to reduce ''Staphylococcus aureus'' in the management of eczema | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | issue = 10 | date = October 2019 | pmid = 31684694 | pmc = 6818407 | doi = 10.1002/14651858.CD003871.pub3 }}</ref><ref name=":182">{{Cite report |url=https://evidence.nihr.ac.uk/collection/eczema-in-children-uncertainties-addressed/ |title=Eczema in children: uncertainties addressed |date=2024-03-19 |publisher=NIHR Evidence |doi=10.3310/nihrevidence_62438 |language=en|url-access=subscription }}</ref><ref>{{Cite web |date=2021-03-02 |title=Secondary bacterial infection of eczema and other common skin conditions: antimicrobial prescribing. NICE guideline [NG190] |url=https://www.nice.org.uk/guidance/ng190/chapter/Recommendations |access-date=2024-07-26 |website=National Institute for Health and Care Excellence}}</ref>

=== Food poisoning ===
''Staphylococcus aureus'' is also responsible for [[foodborne illness|food poisoning]] and achieves this by generating toxins in the food, which is then ingested.<ref>{{cite web |url= https://www.cdc.gov/foodsafety/diseases/staphylococcal.html |title= Staphylococcal Food Poisoning |date=4 October 2016|website=cdc.gov |publisher=hhs.gov |access-date= 23 October 2016}}</ref> Its [[incubation period]] lasts 30 minutes to eight hours,<ref>"Staphylococcus." Foodsafety.gov, U.S. Department of Health and Human Services, https://www.foodsafety.gov/poisoning/causes/bacteriaviruses/staphylococcus/.</ref> with the illness itself lasting from 30 minutes to 3 days.<ref>"Staphylococcal Food Poisoning." Food Safety, Centers for Disease Control and Prevention, 4 October 2016, https://www.cdc.gov/foodsafety/diseases/staphylococcal.html.</ref> Preventive measures one can take to help prevent the spread of the disease include washing hands thoroughly with soap and water before preparing food. The [[Centers for Disease Control and Prevention]] recommends staying away from any food if ill, and wearing gloves if any open wounds occur on hands or wrists while preparing food. If storing food for longer than 2 hours, it is recommended to keep the food [[Temperature danger zone|below 4.4 or above 60 °C]] (below 40 or above 140&nbsp;°F).<ref>{{cite web | vauthors = Woodson J |title=Centers for disease control and prevention |url= https://www.cdc.gov/foodsafety/diseases/staphylococcal.html |archive-url= https://web.archive.org/web/20160208065403/http://www.cdc.gov/foodsafety/diseases/staphylococcal.html |url-status=live |archive-date=8 February 2016 |website=Food Safety |access-date=24 October 2017 }}</ref>

=== Bone and joint infections ===
''Staphylococcus aureus'' is a common cause of major bone and joint infections, including [[osteomyelitis]], [[septic arthritis]], and infections following [[joint replacement]] surgeries.<ref name=Rasmussen2011/><ref name=Tong2015/><ref>{{cite journal |vauthors=Latha T, Anil B, Manjunatha H, Chiranjay M, Elsa D, Baby N, Anice G |title=MRSA: the leading pathogen of orthopedic infection in a tertiary care hospital, South India |journal=Afr Health Sci |volume=19 |issue=1 |pages=1393–1401 |date=March 2019 |pmid=31148966 |pmc=6531934 |doi=10.4314/ahs.v19i1.12 }}</ref>

=== Bacteremia ===
''Staphylococcus aureus'' is a leading cause of [[bloodstream infection]]s throughout much of the industrialized world.<ref name=Rasmussen2011>{{cite journal | vauthors = Rasmussen RV, Fowler VG, Skov R, Bruun NE | title = Future challenges and treatment of ''Staphylococcus aureus'' bacteremia with emphasis on MRSA | journal = Future Microbiology | volume = 6 | issue = 1 | pages = 43–56 | date = January 2011 | pmid = 21162635 | pmc = 3031962 | doi = 10.2217/fmb.10.155 }}</ref> Infection is generally associated with breaks in the skin or mucosal membranes due to surgery, injury, or use of [[intravascular]] devices such as [[cannula]]s, [[hemodialysis]] machines, or [[hypodermic needle]]s.<ref name=Tong2015/><ref name=Rasmussen2011/> Once the bacteria have entered the bloodstream, they can infect various organs, causing [[infective endocarditis]], [[septic arthritis]], and [[osteomyelitis]].<ref name=Rasmussen2011/> This disease is particularly prevalent and severe in the very young and very old.<ref name=Tong2015/>

Without antibiotic treatment, ''S. aureus'' bacteremia has a [[case fatality rate]] around 80%.<ref name=Tong2015/> With antibiotic treatment, case fatality rates range from 15% to 50% depending on the age and health of the patient, as well as the antibiotic resistance of the ''S. aureus'' strain.<ref name=Tong2015/>

===Medical implant infections===
''Staphylococcus aureus'' is often found in [[biofilm]]s formed on medical devices implanted in the body or on human tissue. It is commonly found with another pathogen, ''[[Candida albicans]]'', forming multispecies biofilms. The latter is suspected to help ''S. aureus'' penetrate human tissue.<ref name="pmid25332378"/> A higher mortality is linked with multispecies biofilms.<ref>{{cite journal | vauthors = Zago CE, Silva S, Sanitá PV, Barbugli PA, Dias CM, Lordello VB, Vergani CE | title = Dynamics of biofilm formation and the interaction between Candida albicans and methicillin-susceptible (MSSA) and -resistant ''Staphylococcus aureus'' (MRSA) | journal = PLOS ONE | volume = 10 | issue = 4 | pages = e0123206 | year = 2015 | pmid = 25875834 | pmc = 4395328 | doi = 10.1371/journal.pone.0123206 | doi-access = free | bibcode = 2015PLoSO..1023206Z }}</ref>

''Staphylococcus aureus'' biofilm is the predominant cause of orthopedic implant-related infections, but is also found on cardiac implants, [[Vascular bypass|vascular grafts]], various [[catheter]]s, and cosmetic surgical implants.<ref name=":1">{{cite journal | vauthors = Nandakumar V, Chittaranjan S, Kurian VM, Doble M | date = 2013 | title = Characteristics of bacterial biofilm associated with implant material in clinical practice |journal=Polymer Journal|volume=45|issue=2|pages=137–152|doi=10.1038/pj.2012.130 | doi-access = free }}</ref><ref name="Archer_2011">{{cite journal | vauthors = Archer NK, Mazaitis MJ, Costerton JW, Leid JG, Powers ME, Shirtliff ME | title = ''Staphylococcus aureus'' biofilms: properties, regulation, and roles in human disease | journal = Virulence | volume = 2 | issue = 5 | pages = 445–459 | date = 1 September 2011 | pmid = 21921685 | pmc = 3322633 | doi = 10.4161/viru.2.5.17724 }}</ref> After implantation, the surface of these devices becomes coated with host proteins, which provide a rich surface for bacterial attachment and biofilm formation. Once the device becomes infected, it must be completely removed, since ''S. aureus'' biofilm cannot be destroyed by antibiotic treatments.<ref name="Archer_2011"/>

Current therapy for ''S. aureus'' biofilm-mediated infections involves surgical removal of the infected device followed by antibiotic treatment. Conventional antibiotic treatment alone is not effective in eradicating such infections.<ref name=":1" /> An alternative to postsurgical antibiotic treatment is using antibiotic-loaded, dissolvable calcium sulfate beads, which are implanted with the medical device. These beads can release high doses of antibiotics at the desired site to prevent the initial infection.<ref name="Archer_2011"/>

Novel treatments for ''S. aureus'' biofilm involving nano silver particles, [[bacteriophage]]s, and plant-derived antibiotic agents are being studied. These agents have shown inhibitory effects against ''S. aureus'' embedded in biofilms.<ref>{{cite journal | vauthors = Chung PY, Toh YS | title = Anti-biofilm agents: recent breakthrough against multi-drug resistant ''Staphylococcus aureus'' | journal = Pathogens and Disease | volume = 70 | issue = 3 | pages = 231–9 | date = April 2014 | pmid = 24453168 | doi = 10.1111/2049-632x.12141 | doi-access = free }}</ref> A class of [[Enzyme|enzym]]es have been found to have biofilm matrix-degrading ability, thus may be used as biofilm dispersal agents in combination with antibiotics.<ref>{{cite journal | vauthors = Hogan S, Zapotoczna M, Stevens NT, Humphreys H, O'Gara JP, O'Neill E | title = Potential use of targeted enzymatic agents in the treatment of ''Staphylococcus aureus'' biofilm-related infections | journal = The Journal of Hospital Infection | volume = 96 | issue = 2 | pages = 177–182 | date = June 2017 | pmid = 28351512 | doi = 10.1016/j.jhin.2017.02.008 }}</ref>

=== Animal infections ===
''Staphylococcus aureus'' can survive on dogs,<ref name="Epidemiol2008-Boost">{{cite journal | vauthors = Boost MV, O'Donoghue MM, James A | title = Prevalence of ''Staphylococcus aureus'' carriage among dogs and their owners | journal = Epidemiology and Infection | volume = 136 | issue = 7 | pages = 953–964 | date = July 2008 | pmid = 17678561 | pmc = 2870875 | doi = 10.1017/S0950268807009326 }}</ref> cats,<ref name="CanVet2009-Hanselman">{{cite journal | vauthors = Hanselman BA, Kruth SA, Rousseau J, Weese JS | title = Coagulase positive staphylococcal colonization of humans and their household pets | journal = The Canadian Veterinary Journal | volume = 50 | issue = 9 | pages = 954–8 | date = September 2009 | pmid = 19949556 | pmc = 2726022 }}</ref> and horses,<ref name="CanVet2008-Burton">{{cite journal | vauthors = Burton S, Reid-Smith R, McClure JT, Weese JS | title = ''Staphylococcus aureus'' colonization in healthy horses in Atlantic Canada | journal = The Canadian Veterinary Journal | volume = 49 | issue = 8 | pages = 797–9 | date = August 2008 | pmid = 18978975 | pmc = 2465786 }}</ref> and can cause [[bumblefoot (infection)|bumblefoot]] in chickens.<ref>{{cite web |title=Staphylococcosis, Staphylococcal Arthritis, Bumble Foot |publisher=The Poultry Site |url=http://www.thepoultrysite.com/diseaseinfo/143/staphylococcosis-staphylococcal-arthritis-bumble-foot |access-date=22 October 2013}}</ref> Some believe health-care workers' dogs should be considered a [[Disease vector|significant source]] of antibiotic-resistant ''S. aureus'', especially in times of outbreak.<ref name="Epidemiol2008-Boost" /> In a 2008 study by Boost, O'Donoghue, and James, it was found that just about 90% of ''S. aureus'' colonized within pet dogs presented as resistant to at least one antibiotic. The nasal region has been implicated as the most important site of transfer between dogs and humans.<ref>{{cite journal | vauthors = Boost MV, O'Donoghue MM, James A | title = Prevalence of ''Staphylococcus aureus'' carriage among dogs and their owners | journal = Epidemiology and Infection | volume = 136 | issue = 7 | pages = 953–964 | date = July 2008 | pmid = 17678561 | pmc = 2870875 | doi = 10.1017/s0950268807009326 | hdl = 10397/7558 }}</ref>

''Staphylococcus aureus'' is one of the causal agents of [[mastitis]] in dairy [[cow]]s. Its large [[polysaccharide]] capsule protects the organism from recognition by the cow's [[Immune system|immune defenses]].<ref>{{cite journal | vauthors = Cenci-Goga BT, Karama M, Rossitto PV, Morgante RA, Cullor JS | title = Enterotoxin production by ''Staphylococcus aureus'' isolated from mastitic cows | journal = Journal of Food Protection | volume = 66 | issue = 9 | pages = 1693–6 | date = September 2003 | pmid = 14503727 | doi = 10.4315/0362-028X-66.9.1693 | doi-access = free | url = http://meridian.allenpress.com/jfp/article-pdf/66/9/1693/1676680/0362-028x-66_9_1693.pdf }}</ref>