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Applied and Environmental Microbiology, July 2007, p. 4357-4358, Vol. 73, No. 13
0099-2240/07/$08.00+0     doi:10.1128/AEM.00202-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Urban Feral Pigeons (Columba livia) as a Source for Air- and Waterborne Contamination with Enterocytozoon bieneusi Spores{triangledown}

Thaddeus K. Graczyk,1,2* Deirdre Sunderland,1 Ana M. Rule,1 Alexandre J. da Silva,3 Iaci N. S. Moura,3,4 Leena Tamang,1 Autumn S. Girouard,2 Kellogg J. Schwab,1 and Patrick N. Breysse1

Division of Environmental Health Engineering, Department of Environmental Health Sciences,1 Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205,2 Division of Parasitic Diseases, National Center for Zoonotic, Vector-borne, and Enteric Diseases, Centers for Disease Control and Prevention, Public Health Service, U.S. Department of Health and Public Services, Atlanta, Georgia 30341,3 Atlanta Research and Education Foundation and Atlanta VA Medical Center, Decatur, Georgia 303334

Received 25 January 2007/ Accepted 27 April 2007


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ABSTRACT
 
This study demonstrated that a person with 30 min of occupational or nonoccupational exposure to urban feral pigeons, such as exposure through the cleaning of surfaces contaminated with pigeon excrement, could inhale approximately 3.5 x 103 Enterocytozoon bieneusi spores and that 1.3 x 103 spores could be inhaled by a nearby person.


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INTRODUCTION
 
Microsporidia are on the Contaminant Candidate List of the U.S. Environmental Protection Agency due to their unknown transmission routes, the challenging spore identification process (14), and the complex treatment of infections with these organisms (5). The zoonotic transmission of Enterocytozoon bieneusi remains a possibility as this species infects a wide range of mammals (4, 13) and birds (9, 10, 12, 13, 15). Most metropolitan cities are inhabited by large populations of feral pigeons, creating the opportunity for frequent contact with humans (8). Thus, there is a potential risk of spore transmission from feral pigeons to people through occupational exposure or casual interactions. The purpose of the present study was to determine if long-term feral pigeon congregation sites present any public health or occupational risks for the transmission of E. bieneusi spores to human populations.

The study site was a surface depression on the flat, tar paper-covered roof (12 by 48 m, i.e., 576 m2) of a three-floor townhouse in Baltimore, MD (76°35'21.42''W, 39°17'52.71''N). The rooftop depression was a visible, permanent, and undisturbed gathering site for large numbers of feral pigeons (Columba livia). Feral pigeons used this site throughout the year for bathing, defecating, sheltering, and cooling down, and the pigeon population fluctuated between 10 and approximately 550 daily. After several years, such conditions resulted in a thick (approximately 10-cm) deposition of pigeon excreta, i.e., guano. Five 1-liter water samples with sediments and two samples (approximately 0.5 kg each) of guano were collected at approximately 3-week intervals. Air was sampled during dry weather while the rooftop depression was swept with a heavy-duty contractor broom to simulate conditions of heavy disturbance. Air was sampled continuously during the 30-min sweeping period by using two personal air samplers and an area sampler, i.e., Biosampler (3, 11).

Water and guano samples were gravity sedimented overnight at 4°C (2), 50 ml of the top layer was collected into a sterile plastic tube and centrifuged (5,000 x g for 10 min), the supernatant was discharged, and the pellet was processed by sugar-phenol flotation (2). The phosphate-buffered saline (PBS) from the Biosampler was centrifuged (5,000 x g for 10 min), the supernatant was discharged, and the pellet was resuspended in 100 µl of sterile PBS. Air filters from the personal sampling devices were dissolved in 1.5 ml of sterile PBS in a water bath at 45°C. The suspension was centrifuged at 45°C (5,000 x g for 10 min), the supernatant was discharged, and the pellet was resuspended in 100 µl of sterile PBS. Duplicate direct wet smears prepared from all samples were air dried, fixed with methanol, and stained with Chromotrope-2R and calcofluor white M2R (2). The remaining samples were coded, and multiplex fluorescence in situ hybridization assays for E. intestinalis, E. hellem, E. cuniculi, and E. bieneusi in 1.5-ml microcentrifuge tubes were carried out as described previously (6, 7, 16). For confirmation, one combined sample of water and two air samples were assayed by PCR (6).

The multiplex fluorescence in situ hybridization assays identified potentially viable E. bieneusi spores in all water, guano, and air samples (Table 1). The overall concentrations of E. bieneusi spores in water and guano samples were 3.8 x 104/liter and 3.6 x 103/g, respectively (Table 1). The total numbers of E. bieneusi spores recovered by the two personal air samplers were 1.1 x 103 and 1.0 x 103, resulting in concentrations of airborne spores of 1.8 x 104 and 1.7 x 104/m3, respectively (Table 1). The total number of E. bieneusi spores recovered from the Biosampler was 3.2 x 103, resulting in an airborne-spore concentration of 0.9 x 104/m3 (Table 1). PCR amplification confirmed the presence of E. bieneusi DNA among DNA extracted from spores in water and air samples.


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  		TABLE 1. Detection of E. bieneusi spores in water, pigeon guano, and disturbed-condition air samples collected at a long-term feral urban pigeon (C. livia) congregation site

The present study demonstrated that (i) E. bieneusi was the only microsporidian parasite recovered from the urban feral pigeon congregation site that is virulent in humans; (ii) E. bieneusi spores can be aerosolized from disturbed excrements of pigeons and may potentially be inhaled by humans as airborne particles; and (iii) air, water, and pigeon guano may contain potentially viable E. bieneusi spores and, thus, can serve as a source of air- and waterborne contamination.

Given a breathing volume of 9,600 liters/8 h for a moderately active person (1) and the concentration of airborne E. bieneusi spores determined by personal air samplers (Table 1), the present study demonstrated that a person with 30 min of occupational exposure to pigeons, e.g., through cleaning surfaces contaminated with their excrements, could inhale approximately 1.05 x 104 spores. Given the fact that approximately 30% of airborne spores were potentially viable, the number of inhaled viable spores may reach approximately 3.5 x 103. The data on the concentration of E. bieneusi spores determined by the Biosampler indicate that a person standing for 30 min within an area that contained pigeon excrements while disturbance was conducted could inhale a total of 5.4 x 103 spores, of which approximately 1.3 x 103 would be potentially viable.

The total rainfall for the study area during the sampling period (28 June 2006 to 4 October 2006) was 26.6 cm (http://www.weather.gov/climate/index.php?wfo=lwx). Given the size of the rooftop drainage of 12 by 48 m (576 m2) and the maximum volume of the rooftop depression of approximately 350 liters, the accumulation of pigeon guano at this site was flushed over 4.5 x 102 times with rainwater during the sampling period. As the average concentration of waterborne E. bieneusi spores at this site was 3.8 x 104/liter, the rainwater runoff from this pigeon congregation site delivered an enormous number of E. bieneusi spores to the nearby urban storm water runoff system.


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ACKNOWLEDGMENTS
 
We thank T. Shields for geographical coordinates and B. Steinberg and B. Piskorski for access to the study site.

The study was supported by the Johns Hopkins Center in Urban Environmental Health (grant no. P30 ES03819), the Johns Hopkins Faculty Research Innovation Fund, the University of the District of Columbia, the U.S. Environmental Protection Agency STAR Program (grant no. RD83300201), and the Fulbright Senior Specialist Fellowship (grant no. 2225 to T. K. Graczyk).

The views expressed herein have not been subjected to U.S. Environmental Protection Agency review and therefore do not necessarily reflect the views of the agency, and no official endorsement should be inferred.


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FOOTNOTES
 
* Corresponding author. Mailing address: Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205. Phone: (410) 614-4984. Fax: (410) 955-0105. E-mail: tgraczyk{at}jhsph.edu Back

{triangledown} Published ahead of print on 4 May 2007. Back


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REFERENCES
 
    1
  1. Agency for Toxic Substances and Disease Registry. 2006. Public health assessment guidance manual. Agency for Toxic Substances and Disease Registry, Washington, DC.
    2. 2
  2. Ash, L. R., and T. C. Orihel. 1987. Parasites: a guide to laboratory procedures and identification, p. 327. ASCP Press, Chicago, IL.
    3. 3
  3. Clark Burton, N., A. Adhikari, S. A. Grinshpun, R. Hornung, and T. Reponen. 2005. The effect of filter material on bioaerosol collection of Bacillus subtilis spores used as a Bacillus anthracis stimulant. J. Environ. Monit. 7:475-480.[CrossRef][Medline]
    4. 4
  4. Dengjel, B., M. Zahler, W. Hermanns, K. Heinritzi, T. Spillmann, A. Thomschke, T. Loscher, R. Gothe, and H. Rinder. 2001. Zoonotic potential of Enterocytozoon bieneusi. J. Clin. Microbiol. 39:4495-4499.[Abstract/Free Full Text]
    5. 5
  5. Didier, E. S., J. A. Maddry, P. J. Brindley, M. E. Stovall, and P. J. Didier. 2005. Therapeutic strategies for human microsporia infections. Expert Rev. Anti-Infect. Ther. 3:419-434.[CrossRef]
    6. 6
  6. Graczyk, T. K., D. B. Conn, F. Lucy, D. Minchin, L. Tamang, L. N. S. Moura, and A. J. DaSilva. 2004. Human waterborne parasites in zebra mussels (Dreissena polymorpha) from the Shannon River drainage, Ireland. Parasitol. Res. 93:389-391.
    7. 7
  7. Graczyk, T. K., A. S. Girouard, L. Tamang, S. P. Nappier, and K. J. Schwab. 2006. Recovery, bioaccumulation, and inactivation of human waterborne pathogens by the Chesapeake Bay nonnative oyster, Crassostrea ariakensis. Appl. Environ. Microbiol. 72:3390-3395.[Abstract/Free Full Text]
    8. 8
  8. Haag-Wackernagel, D., and H. Moch. 2004. Health hazards posed by feral pigeons. J. Infect. 48:307-313.[CrossRef][Medline]
    9. 9
  9. Haro, M., F. Izquiero, N. Henriques-Gil, A. F. Alonso, S. Fenoy, and C. Del Aquila. 2005. First detection and genotyping of human-associated microsporidia in pigeons from urban parks. Appl. Environ. Microbiol. 71:3153-3157.[Abstract/Free Full Text]
    10. 10
  10. Haro, M., N. Henriques-Gil, S. Fenoy, F. Izquierdo, F. Alonso, and C. Del Aguila. 2006. Detection and genotyping of Enterocytozoon bieneusi in pigeons. J. Eukaryot. Microbiol. 53:S58-S60.[CrossRef][Medline]
    11. 11
  11. Lin, X. J., T. Reponen, K. Willeke, Z. Wang, S. A. Grinshpun, and M. Trunov. 2000. Survival of airborne microorganisms during swirling aerosol collection. Aerosol Sci. Technol. 32:184-196.[CrossRef]
    12. 12
  12. Lobo, M. L., L. Xiao, V. Cama, N. Magalhaes, F. Antunes, and O. Matos. 2006. Identification of potentially human-pathogenic Enterocytozoon bieneusi genotypes in various birds. Appl. Environ. Microbiol. 72:7380-7382.[Abstract/Free Full Text]
    13. 13
  13. Mathis, A., B. Weber, and P. Deplazes. 2005. Zoonotic potential of the microsporidia. Clin. Microbiol. Rev. 18:423-445.[Abstract/Free Full Text]
    14. 14
  14. Nwachcuku, N., and C. P. Gerba. 2004. Emerging waterborne pathogens: can we kill them all? Curr. Opin. Biotechnol. 15:175-180.[CrossRef][Medline]
    15. 15
  15. Reetz, J., H. Rinder, A. Thomschke, H. Manke, M. Schwebs, and A. Bruderek. 2002. First detection of the microsporidium Enterocytozoon bieneusi in non-mammalian hosts (chickens). Int. J. Parasitol. 32:785-787.[CrossRef][Medline]
    16. 16
  16. Slodkowicz-Kowalska, A., T. K. Graczyk, L. Tamang, S. Jedrzejewski, A. Nowosad, P. Zduniak, P. Solarczyk, A. S. Girouard, and A. C. Majewska. 2006. Microsporidian species known to infect humans are present in aquatic birds: implications for transmission via water? Appl. Environ. Microbiol. 72:4540-4544.[Abstract/Free Full Text]

Applied and Environmental Microbiology, July 2007, p. 4357-4358, Vol. 73, No. 13
0099-2240/07/$08.00+0     doi:10.1128/AEM.00202-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

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  • Bart, A., Wentink-Bonnema, E. M., Heddema, E. R., Buijs, J., van Gool, T. (2008). Frequent Occurrence of Human-Associated Microsporidia in Fecal Droppings of Urban Pigeons in Amsterdam, The Netherlands. Appl. Environ. Microbiol. 74: 7056-7058 [Abstract] [Full Text]  

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