Morphology Gram-positive cocci, usually occurs in clusters, nonspore forming, non-motile, coagulase positive, facultative anaerobes.
Growth Conditions Tryptic Soy Broth
Health Hazards
Host Range Humans and Animals.
Modes of Transmission  Ingestion of food containing enterotoxins, contact with nasal carriers, contact with draining lesions or purulent discharges, also spread by person-to-person contact; Indirectly by contact with fomites, Indirectly or directly by contact with infected animals.
Signs and Symptoms  Accidental ingestion: Violent onset of severe nausea, cramps, vomiting, and diarrhea if preformed enterotoxin is present. Surface infections: Impetigo, follicutis, abscesses, boils, infected lacerations. Systemic infections: onset of fever, headache, myalgia, can progress to endocarditis, meningitis, septic arthritis, pneumonia, osteomyelitis, sepsis.
Infectious Dose Virulence varies for different strains.
Incubation Period  30 minutes to 8 hours when consuming contaminated food with enterotoxin. Otherwise, typically 4 to 10 days. Disease may not occur until several months after colonization of mucosal surfaces.
Medical Precautions/Treatment
Prophylaxis Hand-hygiene; Elimination of nasal carriage by using topical mupirocin. Mupirocin also eliminates transient hand carriage by eliminating the mucosal reservoir.
Vaccines None
Treatment Incision and drainage for localized skin infections; antibiotic therapy for severe infections; Many strains resistant to antibiotics; Sensitivity must be determined for each strain.
Surveillance Monitor for signs of food poisoning when ingestion occurs. Monitor for skin inflammation; isolation of organism from wound, blood, CSF or urine.
MSU Requirements  Report any exposures
Laboratory Hazards
Laboratory Acquired Infections (LAIs) 29 reported cases up to 1973 with 1 death. Most common cause of laboratory infection was accidental self-exposure via the mucous membranes by touching contaminated hands to face or eyes.
 Sources Contaminated food, blood, abscesses, lesion exudates, CFS, respiratory specimen, feces, and urine
Supplemental References
BMBL:5th Edition
Canadian MSDS
Containment Requirements
BSL2 For all procedures involving known or potentially infected cultures.
ABSL2 For all procedures utilizing infected animals.
Spill Procedures
Small Notify others working in the lab. Remove and don new PPE. Cover area of the spill with absorbent material and add 10 % Bleach. Allow 30 minutes hour of contact time. After 30 minutes and then cleanup and dispose of materials.
Large For assistance, contact MSU's Biosafety Officer: Ryan Bartlett,, (406) 994-6733
or Safety and Risk Management (406-994- 2711).
Exposure Procedures
Mucous membrane
Flush eyes, mouth or nose for 5 minutes at eyewash station.
Other Exposures
Wash area with soap and water for 5 minutes.
Immediately report incident to supervisor, complete a first report of injury report, and submit to Safety and Risk Management.
Medical Follow-up
During business hours: Bridger Occupational Health 3406 Laramie Drive. Weekdays 8am -6pm.  Weekends 9am-5pm
After business hours: Bozeman Deaconess Hospital Emergency Room 915 Highland Blvd Bozeman, MT
Disinfection Susceptible to 10 % Bleach, 70 % ethanol, and 2 % gluteraldehyde, chlorohexadine, formaldehyde, and 0.25 % benzalkonium chloride.
Inactivation Inactivated by dry heat (1 hour at 160-170° C).
Survival Outside Host Carcass and organs – 42 days; Skin – 30 minutes to 38 days; meat products – 60 days; floor – less than 7 days; glassware – 46 hours; sunlight – 17 days; UV light – 7 hours.
Personal Protective Equipment (PPE)
Minimum PPE Requirements At minimum, gloves, closed toed shoes, lab coat, and appropriate face and eye protection prior to working with S. aureus. Additional PPE may be required depending on lab specific SOPs
Additional Precautions Avoid injuries from contaminated sharp instruments, bites and scratches from infected animals, and direct contact with open skin or lesions of skin.