Staphylococcus epidermidis (S. epidermidis)
| Characteristics | |
|---|---|
| Morphology | Gram-positive, catalase positive cocci belonging to the Staphylococcaceae family. Approximately 0.5-1.5 µm in diameter, nonmotile, non-spore-forming, facultative anaerobes that usually form in clusters (grape-like). Belongs to the group of coagulase-negative staphylococci (CoNS), which is distinguished from coagulase-positive staphylococci such as S. aureus. Biofilm formation occurs with initial adhesion to a foreign surface or endothelium allowing the colony to survive in harsh environments. Various immune evasion factors are also produced by the pathogen (ex. Poly-γ-glutamic acid, Phenol-soluble modulins) |
| Growth Conditions | Colonies are formed on all rich media including tryptic soy agar (TSA) at 37°C, brain heart infusion (BHI) agar and Luria Bertani (LB) agar. |
| Health Hazards | |
|---|---|
| Host Range | Humans |
| Modes of Transmission | S. epidermidis is an opportunistic pathogen that can cause virulence once it invades the human body, often via medical and prosthetic devices. It is also highly prevalent among neonates. Can also be transmitted by direct or indirect contact with a person who has a discharging wound or clinical infection of the respiratory or urinary tract, or who is colonized with the organism. |
| Signs and Symptoms | Skin infections can look like pimples or boils, sometimes there is pus or other drainage. They can turn into impetigo, which turns into a crust on the skin, or cellulitis, a swollen, red area of skin that feels hot. Bone infections can cause pain, swelling, warmth and redness in the infected area, chills, and a fever. Exposure via ingestion typically causes nausea and vomiting, diarrhea, and a fever. If you lose too many fluids, you may also become dehydrated. Respiratory infection (pneumonia) symptoms include a high fever, chills, and cough that doesn't get better. You may also have chest pain and shortness of breath. |
| Infectious Dose | Unknown |
| Incubation Period | Typically 4-10 days |
| Medical Precautions/Treatment | |
|---|---|
| Prophylaxis | Hand-hygiene, sterilization of equipment (especially if used in a medical setting) |
| Vaccines | None publically available |
| 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 bodily fluid samples aids in prescribing treatment. Rapid molecular methods include use of peptide nucleic acid (PNA) in fluorescence in situ hybridization (FISH) |
| GWU Requirements | Report all incidents to the Office of Risk Management as well as the Office of Research Safety (ORS) IMMEDIATELY FOLLOWING THE OCCURRENCE. |
| Containment | |
|---|---|
| BSL-2 | Risk Group 2 classification is applied to S. epidermidis. BSL-2 practices, containment equipment, and facilities are recommended for all activities utilizing known or potentially infected clinical materials or cultures. All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). |
| ABSL-2 | ABSL-2 facilities are recommended for studies utilizing infected laboratory animals. |
| Spill Procedures | |
|---|---|
| Small Spills (<1 liter) | If the spill occurred inside a biological safety cabinet, close the sash and allow the cabinet to operate for 15 minutes before continuing with the spill cleanup.
S. epidermidis can become aerosolized and contaminate surrounding surfaces, caution should be taken during a spill outside of a BSC. Leave the room immediately and allow the aerosols to dissipate for 15 minutes. Notify others working in the lab. Don appropriate PPE. Cover area of the spill with paper towels or any absorbent material and apply an EPA registered disinfectant effective against Gram-positive bacteria (ethanol, bleach, glutaraldehyde), working from the perimeter towards the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials. |
| Large Spills | Alert lab personnel in the laboratory to the spill and keep people out of the area to prevent spread of the contamination. Check if you have been contaminated or if any of your PPE has been breached. If so follow exposure procedures. Remove any contaminated clothing and place it the biohazard waste. Wash your hands and post a sign on the door. Notify your supervisor of the incident and call ORS (4-8258) for assistance. If the situation involves an imminently life-threatening injury or has catastrophic potential, call 911. |
| Exposure Procedures | |
|---|---|
| Mucus Membrane | Flush eyes, mouth or nose for 15 minutes at eyewash station. |
| Other Exposure | For an area not protected by skin, wash with soap and water for 15 minutes (open wounds, sores, etc.), and a minimum of 20 seconds of soap and water for areas with intact skin. |
| Reporting | Report ALL injuries to the PI immediately and reported to the Office of Risk Management at [email protected] IMMEDIATELY FOLLOWING THE OCCURRENCE. Exposures that involve a bloodborne-pathogen or recombinant DNA also need to be reported to the Office of Research Safety at [email protected]. If the injury requires immediate medical attention, call GWPD at 202-994-6111 or call 911. |
| Medical Monitoring | Seek immediate medical evaluation, treatment, and post exposure follow-up at the Employee Health Office at GWU Hospital (900 23rd St., NW, Suite G-1090, Phone: 202-715-4275). Students should go to the Students Health Office at Marvin Center. After hours treatment can be received at the GWU hospital emergency room. |
| Stability | |
|---|---|
| Disinfection | Susceptible to 10% bleach, 70% ethanol, 2% glutaraldehyde. |
| Inactivation | Sensitive to dry heat treatment of 160-170oC for at least an hour, but not to moist heat treatment |
| Survival Outside Host | Due to biofilm formation on surfaces, bacteria is quite resilient in most environments |
| Personal Protective Equipment (PPE) | |
|---|---|
| Minimum PPE Requirements | At minimum, personnel are required to don gloves, closed toed shoes, lab coat, and appropriate face and eye protection prior to working with S. epidermidis. Additional PPE may be required depending on lab specific SOPs. |
| Additional Precautions | Additional protection may be worn over laboratory clothing when infectious materials are directly handled, such as solid-front gowns with tight fitting wrists, gloves, and respiratory protection. Wash hands with soap and water after removing gloves. |
| References | |
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