Clostridium difficile is a bacterial healthcare-associated infection, which houseflies Musca domestica
may transfer due to their synanthropic nature. The aims of this thesis were to determine the ability of
M. domestica to transfer C. difficile mechanically and to collect and identify flying insects in UK
hospitals and classify any associated bacteria. M. domestica exposed to independent suspensions of
vegetative cells and spores of C. difficile were able to mechanically transfer the bacteria on to agar for
up to 4 hours following exposure. C. difficile could be recovered from fly excreta for 96hrs and was
isolated from the M. domestica alimentary canal. Also confirmed was the carriage of C. difficile by M.
domestica larvae, although it was not retained in the pupae or in the adults that subsequently
developed. Flying insects were collected from ultra-violet light flytraps in hospitals. Flies (order
Diptera) were the most commonly identified. Chironomidae were the most common flies, Calliphora
vicina were the most common synanthropic fly and ‘drain flies’ were surprisingly numerous and
represent an emerging problem in hospitals. External washings and macerates of flying insects were
prepared and inoculated onto a variety of agars and following incubation bacterial colonies identified
by biochemical tests. A variety of flying insects, including synanthropic flies (e.g. M. domestica and
C. vicina) collected from UK hospitals harboured pathogenic bacteria of different species.
Enterobacteriaceae were the group of bacteria most commonly isolated, followed by Bacillus spp,
Staphylococci, Clostridia, Streptococci and Micrococcus spp. This study highlights the potential for
M. domestica to contribute to environmental persistence and spread of C. difficile in hospitals. Also
illustrated is the potential for flying insects to contribute to environmental persistence and spread of
other pathogenic bacteria in hospitals and therefore the need to implement pest control as part of
infection control strategies.
Date of Award | 12 Feb 2015 |
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Original language | English |
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Supervisor | Anthony Hilton (Supervisor) |
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- musca domestica
- flies
- pest control
- infection control
- disease
Isolation and characterisation of bacteria associated with flying insects in hospitals, with particular emphasis on Clostridium difficile
Davies, M. (Author). 12 Feb 2015
Student thesis: Doctoral Thesis › Doctor of Philosophy