Akademik

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A genus of nonmotile, nonspore-forming, aerobic to facultatively anaerobic bacteria (family Micrococcaceae) containing Gram-positive, spherical cells, 0.5–1.5 μm in diameter, which divide in more than one plane to form irregular clusters. These organisms are chemoorganotrophic, and their metabolism is respiratory and fermentative. Under anaerobic conditions, lactic acid is produced from glucose; under aerobic conditions, acetic acid and small amounts of CO₂ are produced. Coagulase-positive strains produce a variety of toxins and are therefore potentially pathogenic and may cause food poisoning. These organisms are usually susceptible to antibiotics such as the β-lactam and macrolide antibiotics, tetracyclines, novobiocin, and chloramphenicol but are resistant to polymyxin and polyenes. They are susceptible to antibacterials such as phenols and their derivatives, surface-active compounds, salicylanilides, carbanilides, and halogens (chlorine and iodine) and their derivatives, such as chloramines and iodophors. They are found on the skin, in skin glands, on the nasal and other mucous membranes of warm-blooded animals, and in various food products. The type species is S. aureus. [staphylo- + G. kokkos, a berry]

- S. aureus a common species found especially on nasal mucous membrane and skin (hair follicles); bacterial species that produces exotoxins including those that cause toxic shock syndrome, with resulting skin rash, and renal, hepatic, and central nervous system disease, and an enterotoxin associated with food poisoning; it causes furunculosis, cellulitis, pyemia, pneumonia, osteomyelitis, endocarditis, suppuration of wounds, other infections; also a cause of infection in burn patients; humans are the chief reservoir. The type species of the genus S.. SYN: S. pyogenes aureus.

- S. epidermidis a species of bacteria, the most common of the coagulase-negative S. group.

- S. haemolyticus coagulase-negative s. indigenous to human and mammalian hosts.

- S. hominis coagulase-negative s. indigenous to human and mammalian hosts.

- S. pyogenes albus a name formerly applied to the organisms that are now regarded as the mutants of S. aureus that form white colonies.

- S. pyogenes aureus SYN: S. aureus.

- S. saprophyticus a coagulase negative species that causes urinary tract infections.

- S. simulans coagulase-negative s. indigenous to human and mammalian hosts.

- S. species, coagulase-negative includes a group of species present as normal flora of human skin, respiratory, and mucous membrane surfaces. Although a normal commensal, strains are prominent causes of nosocomial infections, especially in patients with implanted intravenous access devices; some strains are abscess forming and cause diverse infections including sinusitis, wound infections, and osteomyelitis.

staph·y·lo·coc·cus .staf-ə-lō-'käk-əs n

1) cap a genus of nonmotile gram-positive spherical bacteria of the family Micrococcaceae that occur singly, in pairs or tetrads, or in irregular clusters and include causative agents of various diseases and disorders (as food poisoning, skin infections, and endocarditis)

2) pl -coc·ci -'käk-.(s)ī any bacterium of the genus Staphylococcus broadly MICROCOCCUS (2)

a genus of Gram-positive nonmotile spherical bacteria occurring in grapelike clusters. Some species are saprophytes; others parasites. Many species produce exotoxin. The species S. aureus is commonly present on skin and mucous membranes; it causes boils and internal abscesses. More serious infections caused by staphylococci include pneumonia, bacteraemia, osteomyelitis, and enterocolitis. See also MRSA.