Role of the moth fly Clogmia albipunctata (Diptera: Psychodinae) as a mechanical vector of bacterial pathogens in German hospitals.

BACKGROUND

The formerly Mediterranean moth fly species Clogmia albipunctata (Diptera: Psychodidae) is now present in Germany, where it has become a common, year-round pest in hospital buildings.

AIM: To investigate the potential of C. albipunctata to transport and transmit bacterial pathogens in infested German hospitals.

METHODS

From June 2011 to May 2012, 271 adult C. albipunctata were collected from four infested hospitals and analysed qualitatively and, in part, quantitatively, for bacterial colonization. Antimicrobial susceptibility testing was performed for selected nosocomial pathogens.

FINDINGS: Forty-five bacterial species representing 40 genera were found to be colonizing C. albipunctata. Among the bacteria isolated were Acinetobacter baumannii, Aeromonas hydrophila, Alcaligenes faecalis, Bacillus cereus, Escherichia coli, Klebsiella pneumoniae ssp. pneumoniae, Pseudomonas aeruginosa, P. fluorescens and Stenotrophomonas maltophilia, with colonization rates of 0-17.5%, 0-16.7%, 0-12.5%, 0-62.1%, 0-2.5%, 0-4.1%, 0-12.5%, 0-7.6% and 0-10%, respectively. Additionally, one strain of both Yersinia frederiksenii and Nocardia spp. was detected. Unlike 11 strains of multi-drug-resistant (MDR) S. maltophilia collected from one hospital, no MDR Enterobacteriaceae were isolated. Acinetobacter spp. colonized C. albipunctata at rates from 2.9% to 36.8%, and revealed a high affinity for the exoskeleton, with up to 2080 colony-forming units per moth fly for A. baumannii.

CONCLUSION

C. albipunctata is a potential mechanical vector of bacterial pathogens associated with nosocomial infections.