Micrococcus luteus

Micrococcus luteus is a round G + / Gram variable coccus of the genus Micrococcus. It is grouped in tetrads and packets just like other micrococci. Studies suggest that these bacteria are protective for humans and reduce the risk of skin cancers. . It occurs as a physiological component of mammalian microflora, in soil, dust, water and air. Micrococcus luteus colonizes the human sweat glands, where it metabolizes effusions and changes their character and odor. Bacteria also colonize the human mouth, oropharyngeal mucosa and upper respiratory tract.

Cultivation and staining

Micrococcus luteus produce a specific pigment that absorbs electromagnetic radiation at wavelengths of 350 to 475 nanometers, which corresponds to ultraviolet radiation. It appears blue to dark purple on Gram-stained slides. The name "luteus" (Latin yellow) corresponds to the appearance under a microscope. Micrococcus luteus forms yellow colonies on agar with mannitol salt. When culturing Micrococcus luteus on toxic organic substances, they overproduce riboflavin, pyridine (an organic aromatic heterocyclic compound of carbon, hydrogen and nitrogen).

Diagnostics

To differentiate from Staphylococcus aureus, a bacitracin sensitivity test (Bacitracin test) can be performed.

Links

References

• VOTAVA, Miroslav. General medical microbiology. 2nd edition. NEPTUN, 2005. 351 p.
• WIKIPEDIA®,. Micrococcus luteus [online]. [cit. 2018-10-05]. <en.wikipedia.org/wiki/Micrococcus_luteus>