Related Experiment Video
Updated: Mar 14, 2026
Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291
Published on: December 10, 2016
The housefly Musca domestica as a mechanical vector of Clostridium difficile
M P Davies1, M Anderson1, A C Hilton2
1Killgerm Chemicals Ltd, Ossett, UK.
Background:
Clostridium difficile is a bacterial healthcare-associated infection that may be transferred by houseflies (Musca domestica) due to their close ecological association with humans and cosmopolitan nature.
Aim:
To determine the ability of M. domestica to transfer C. difficile both mechanically and following ingestion.
Methods:
M. domestica were exposed to independent suspensions of vegetative cells and spores of C. difficile, then sampled on to selective agar plates immediately postexposure and at 1-h intervals to assess the mechanical transfer of C. difficile. Fly excreta was cultured and alimentary canals were dissected to determine internalization of cells and spores.
Findings:
M. domestica exposed to vegetative cell suspensions and spore suspensions of C. difficile were able to transfer the bacteria mechanically for up to 4h upon subsequent contact with surfaces. The greatest numbers of colony-forming units (CFUs) per fly were transferred immediately following exposure (mean CFUs 123.8 +/- 66.9 for vegetative cell suspension and 288.2 +/- 83.2 for spore suspension). After 1h, this had reduced (21.2 +/- 11.4 for vegetative cell suspension and 19.9 +/- 9 for spores). Mean C. difficile CFUs isolated from the M. domestica alimentary canal was 35 +/- 6.5, and mean C. difficile CFUs per faecal spot was 1.04 +/- 0.58. C. difficile could be recovered from fly excreta for up to 96h.
Conclusion:
This study describes the potential for M. domestica to contribute to environmental persistence and spread of C. difficile in hospitals, highlighting flies as realistic vectors of this micro-organism in clinical areas.
Insights
Houseflies (Musca domestica) can mechanically transfer Clostridium difficile bacteria for up to 4 hours after exposure. Flies also excrete C. difficile for up to 96 hours, indicating their role in spreading infections in healthcare settings.
Area of Science:
- Medical Entomology
- Infectious Diseases
- Microbiology
Background:
- Clostridium difficile is a significant healthcare-associated infection.
- Houseflies (Musca domestica) are ubiquitous and share close ecological ties with humans.
- This association suggests houseflies may play a role in pathogen transmission.
Purpose of the Study:
- To investigate the capacity of houseflies (Musca domestica) to transfer Clostridium difficile.
- To determine if transfer occurs mechanically or after ingestion by the flies.
- To assess the duration and extent of C. difficile transfer by houseflies.
Main Methods:
- Houseflies were exposed to suspensions of vegetative C. difficile cells and spores.
- Mechanical transfer was assessed by sampling flies onto selective agar immediately and hourly post-exposure.
- Internalization and excretion were studied by culturing fly excreta and dissecting alimentary canals.
Main Results:
- Houseflies mechanically transferred C. difficile for up to 4 hours.
- Highest transfer rates occurred immediately post-exposure, with significant reduction after 1 hour.
- C. difficile was recovered from fly excreta for up to 96 hours, with detectable levels in the alimentary canal.
Conclusions:
- Musca domestica can act as mechanical vectors for Clostridium difficile.
- Flies contribute to the environmental persistence and spread of C. difficile in clinical settings.
- This highlights the importance of controlling fly populations in hospitals to prevent infection transmission.
