Previous Article | Next Article 
Applied and Environmental Microbiology, September 2008, p. 5549-5555, Vol. 74, No. 17
0099-2240/08/$08.00+0 doi:10.1128/AEM.00809-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.
Prevalence and Genetic Characterization of Cryptosporidium Isolates from Common Brushtail Possums (Trichosurus vulpecula) Adapted to Urban Settings
Nichola J. Hill,*
Elizabeth M. Deane,
and
Michelle L. Power
Department of Biological Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia
Received 8 April 2008/ Accepted 9 July 2008
The common brushtail possum (Trichosurus vulpecula) is one of the most abundant native marsupials in urban Australia, having successfully adapted to utilize anthropogenic resources. The habituation of possums to food and shelter available in human settlements has facilitated interaction with people, pets, and zoo animals, increasing the potential for transmission of zoonotic Cryptosporidium pathogens. This study sought to examine the identity and prevalence of Cryptosporidium species occurring in possums adapted to urban settings compared to possums inhabiting remote woodlands far from urban areas and to characterize the health of the host in response to oocyst shedding. Findings indicated that both populations were shedding oocysts of the same genotype (brushtail possum 1 [BTP1]) that were genetically and morphologically distinct from zoonotic species and genotypes and most closely related to Cryptosporidium species from marsupials. The urban population was shedding an additional five Cryptosporidium isolates that were genetically distinct from BTP1 and formed a sister clade with Cryptosporidium parvum and Cryptosporidium hominis. Possums that were shedding oocysts showed no evidence of pathogenic changes, including elevated levels of white blood cells, diminished body condition (body mass divided by skeletal body length), or reduced nutritional state, suggesting a stable host-parasite relationship typical of Cryptosporidium species that are adapted to the host. Overall, Cryptosporidium occurred with a higher prevalence in possums from urban habitat (11.3%) than in possums from woodland habitat (5.6%); however, the host-specific nature of the genotypes may limit spillover infection in the urban setting. This study determined that the coexistence of possums with sympatric populations of humans, pets, and zoo animals in the urban Australian environment is unlikely to present a threat to public health safety.
* Corresponding author. Mailing address: Department of Biological Sciences, Macquarie University, North Ryde, NSW 2109, Australia. Phone: 612 9850 9259. Fax: 612 9850 8245. E-mail: nhill{at}bio.mq.edu.au
Published ahead of print on 18 July 2008.
Present address: The Chancellery, Australian National University, Canberra, ACT 0200, Australia.
Applied and Environmental Microbiology, September 2008, p. 5549-5555, Vol. 74, No. 17
0099-2240/08/$08.00+0 doi:10.1128/AEM.00809-08
Copyright © 2008, 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»