Dialister spp.
| Characteristics | |
|---|---|
| Morphology | Four species are currently described in the genus Dialister: Dialister pneumosintes, Dialister invisus, Dialister micraerophilus, and Dialister propionicifaciens. They are small, anaerobic or microaerophilic, non-fermentative, gram-negative coccobacilli that grow as small, circular, tiny, and transparent colonies. Many of the strains may be difficult to distinguish from other tiny, gram-negative anaerobic cocci. Due to their biochemical characteristics (i.e., asaccharolytic and nonreactive in conventional biochemical tests), identification often requires molecular methods such as 16S rRNA gene sequencing. |
| Growth Conditions | Dialister species cultures can be grown on Columbia blood agar |
| Health Hazards | |
|---|---|
| Host Range | Humans |
| Modes of Transmission | Due to being a part of normal flora, infections occur when a patient is immunocompromised or when bacterial invasion of sensitive tissue occurs |
| Signs and Symptoms | D. pneu-mosintes and D. invisus have been mainly implicated in oral diseases such as periodontitis, acute necrotizing ulcerative gingivitis, and endodontic infections. More rarely, D. pneumosintes has been isolated from bite wound infections, during respiratory tract and head/neck infections, and in brain abscesses. D. invisus has also been identified in urinary tract specimens from renal transplant recipients. D. micraerophilus strains have been characterized from various human clinical specimens, including bone and blood cultures, whereas the four D. propionicifaciens isolates currently reported were from cutaneous infections and semen. |
| Infectious Dose | Unknown |
| Incubation Period | Will vary based on patient status and site of infection |
| Medical Precautions/Treatment | |
|---|---|
| Prophylaxis | None readily available |
| Vaccines | None readily available |
| Treatment | Antibiotic treatment is available |
| Surveillance | Monitor for symptoms. Nucleic acid-based assays (PCR and DNA hybridization methods) are used for the detection and strain identification |
| 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 Dialister species. BSL-2 practices, containment equipment, and facilities are recommended for activities using clinical materials and diagnostic quantities of infectious cultures. It is recommended that special emphasis be placed on personal protective equipment, handwashing, manipulation of faucet handles, and decontamination of work surfaces to decrease the risk of exposure. |
| 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.
Dialister species are not known to be spread via aerosols, but 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 the bacteria (bleach, ethanol, 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.) |
| 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, 2% glutaraldehyde, 70% ethanol |
| Inactivation | Most vegetative bacteria can be inactivated by moist heat (121°C for 15 min- 30 min) and dry heat (160-170°C for 1-2 hours) |
| Survival Outside Host | Stability data is limited, but due to colonizing human genitourinary regions it can be suggested that they can survive on other surfaces for at least 1 day |
| 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 Dialister spp. 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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