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Staphyloxanthin is a 
When comparing a normal strain of ''S. aureus'' with a strain modified to lack staphyloxanthin, the wildtype pigmented strain was more likely to survive incubation with an oxidizing chemical such as
Staphyloxanthin on www.genome.jp
Carotenoids Glucosides Staphylococcus
carotenoid
Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, cana ...
pigment
A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...
that is produced by some strains of ''Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posi ...
'', and is responsible for the characteristic golden color that gives ''S. aureus'' its species name. Staphyloxanthin also acts as a virulence factor. It has an antioxidant
Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...
action that helps the microbe evade death by reactive oxygen species
In chemistry and biology, reactive oxygen species (ROS) are highly Reactivity (chemistry), reactive chemicals formed from diatomic oxygen (), water, and hydrogen peroxide. Some prominent ROS are hydroperoxide (H2O2), superoxide (O2−), hydroxyl ...
produced by the host immune system.
When comparing a normal strain of ''S. aureus'' with a strain modified to lack staphyloxanthin, the wildtype pigmented strain was more likely to survive incubation with an oxidizing chemical such as hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...
than the mutant strain was. Colonies of the two strains were also exposed to human neutrophils. The mutant colonies quickly succumbed while many of the pigmented colonies survived. Wounds on mice were inoculated with the two strains. The pigmented strains created lingering abscess
An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pre ...
es. Wounds with the unpigmented strains healed quickly. These tests suggest that the staphyloxanthin may be key to the ability of ''S. aureus'' to survive immune system attacks.
Drugs designed to inhibit the bacterium's production of the staphyloxanthin may weaken it and renew its susceptibility to antibiotics. In fact, because of similarities in the pathways for biosynthesis of staphyloxanthin and human cholesterol
Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils.
Cholesterol is biosynthesis, biosynthesized by all anima ...
, a drug developed in the context of cholesterol-lowering therapy was shown to block ''S. aureus'' pigmentation and disease progression in a mouse infection model.
Genomically, the ''crt'' operon primarily underlies the biosynthesis of staphyloxanthin; however, another enzyme, AldH, found outside of the operon, was later identified as also needed for the carotenoid’s production. Recent comparative genomics research has further revealed that the ''crt'' operon is widespread across the ''Staphylococcus'' genus. Non-aureus pigmented staphylococci have long been noted and experimental support for staphyloxanthin production now exists in ''Staphylococcus xylosus'', ''Staphylococcus warneri'', ''Staphylococcus epidermidis'''','' and ''Staphylococcus capitis''. Further, some lineages of ''S. aureus'' have been found to lack ''crt'' genes and some non-aureus staphylococcal isolates have been found to feature multiple copies of ''crt''.
References
{{reflistExternal links
Staphyloxanthin on www.genome.jp
Carotenoids Glucosides Staphylococcus