Author
Becnel, James | |
White, Susan | |
Shapiro, Alexandra |
Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 7/16/2004 Publication Date: 7/16/2004 Citation: 1st United NATO sponsored workshop "Emergent Pathogens in the 21st Century: First United Workshop on Mocrosporidia from Invertebrate and Vertebrate Hosts". Ceske Budejovice, Czech Republic, July 11-16, 2004. Interpretive Summary: N/A. Technical Abstract: Detailed studies on microsporidia can be extremely difficult due to the inability to easily manipulate the parasite and the host organism. Some of these obstacles can be overcome by the study of microsporidia in mosquitoes. Most mosquitoes have relatively short life cycles (2 3 weeks), are readily manipulated in the laboratory, and many can be easily colonized. Microsporidia are common in mosquitoes and include diverse groups with both simple and complex life cycles. For these reasons, the study of microsporidia in mosquitoes has provided many new details on the developmental cycles of microsporidia in general as well as insights into their biological relationships with the host. Microsporidia in mosquitoes can be divided into two categories based on their life cycles and host-parasite relationships. Some species of microsporidia exhibit simple life cycles with one spore type responsible for oral transmission. They affect only one generation of the mosquito and are not usually host or tissue specific. Brachiola algerae (Vavra and Undeen, 1970) and Vavraia culicis (Weiser, 1947) are examples of species with relatively straightforward life cycles (one spore type) and simple host-parasite relationship. Each of these species has been isolated from vertebrate (humans) and invertebrate (mosquito) hosts but possible mechanisms for transmission between hosts is unknown. Heterosporous (polymorphic) microsporidia are characterized by complex life cycles involving multiple spore types responsible for horizontal and vertical transmission. They affect two generations of the mosquito and some involve an obligate intermediate host. Heterosporous microsporidia are generally very host and tissue specific with complex developmental sequences comprised of unique stages and events. The microsporidium Edhazardia aedis (Kudo, 1930) is a pathogen of Aedes aegypti and does not require an intermediate host. The developmental cycle of E. aedis is characterized by four sporulation sequences, two in the parental host and two in the filial generation. Each sequence occurs in specific tissues and stages of the host that can be altered by biological and physiological conditions of the host. |