This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Muscatello, G.
Right arrow Articles by Browning, G. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Muscatello, G.
Right arrow Articles by Browning, G. F.

 Previous Article  |  Next Article 

Journal of Clinical Microbiology, March 2009, p. 734-737, Vol. 47, No. 3
0095-1137/09/$08.00+0     doi:10.1128/JCM.01395-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Detection of Virulent Rhodococcus equi in Exhaled Air Samples from Naturally Infected Foals{triangledown}

G. Muscatello,{dagger} J. R. Gilkerson, and G. F. Browning*

Equine Infectious Disease Laboratory, School of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia

Received 21 July 2008/ Returned for modification 12 October 2008/ Accepted 3 January 2009

Virulent Rhodococcus equi causes pyogranulomatous bronchopneumonia in foals. The route of infection of foals has been considered to be inhalation of aerosolized bacteria from soil that is contaminated with equine feces. Thus, disease caused by R. equi has been regarded as an opportunistic infection of environmental origin and not a contagious disease. In this study, we report the exhalation of virulent R. equi from the respiratory tract of naturally infected foals. A handheld air-monitoring system was used to recover virulent R. equi from the exhaled breath of foals, and the concentration of virulent R. equi organisms in exhaled air was compared to the concentration in environmental air samples taken from the holding pens and lane areas on farms. R. equi strains carrying the vapA gene of the virulence plasmid were detected by using colony blotting and DNA hybridization techniques in cultures of exhaled air from 67% (37/55) of foals tested. The concentration of virulent R. equi organisms in exhaled air from foals was significantly higher than that in environmental air (P < 0.001). There were no significant differences in the median concentrations of virulent R. equi bacteria exhaled by clinically healthy or diseased foals. The high concentrations of virulent R. equi bacteria in exhaled air suggested that aerosol transmission between foals is possible and may have a significant impact on the prevalence of R. equi pneumonia on farms. The air sampling technique described is potentially useful as a noninvasive method for the detection and quantification of virulent R. equi in the respiratory tract of foals.

* Corresponding author. Mailing address: School of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia. Phone: 61 3 8344 7342. Fax: 61 3 8344 7374. E-mail: glenfb{at}unimelb.edu.au

{triangledown} Published ahead of print on 14 January 2009.

{dagger} Present address: Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales 2006, Australia.

Journal of Clinical Microbiology, March 2009, p. 734-737, Vol. 47, No. 3
0095-1137/09/$08.00+0     doi:10.1128/JCM.01395-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»