Study on the species-specificity of Isospora michaelbakeri by experimental infection

Abstract

Isospora michaelbakeri is one of the Isospora species most commonly found in the wild field, which can cause severe infection and mortality in young sparrows. In this study, we selected I. michaelbakeri (Chung Hsing strain) as a pathogen to orally inoculate russet sparrows (Passer rutilans), spotted munia (Lonchura punctulata), canary (Serinus canaria), Java sparrows (Padda oryzivora), chicken (Gallus domesticus), ducks (Anas platyrhynchos) and BALB/c mice. The results indicated that I. michaelbakeri infected only russet sparrows. Infected sparrows displayed lethargy, muscular weakness and fluffy feathers, followed by rapid death. Liver and spleen enlargement was seen in the infected birds. Schizonts were identified in thin smears from the venous blood, enlarged livers and spleens. Histopathological examination revealed schizonts and merozoites from the liver and spleen of infected russet sparrows, but not from other species experimentally inoculated with I. michaelbakeri in the present study.

Coccidia of New World passerine birds (Aves: Passeriformes): a review of Eimeria Schneider, 1875 and Isospora Schneider, 1881 (Apicomplexa: Eimeriidae)

“…In these experiments, oöcysts of I. michaelbakeri Grulet, Landau & Baccam, 1982, a parasite of the sparrow Passer rutilans (Temminck), were used to inoculate their natural host and the following birds: the estrildids passerines Lonchura punctulata (L.) and Padda oryzivora (L.); the fringillid passerine Serinus canaria; the galliform Gallus gallus (L.); and the anseriform Anas platyrhynchos (L.). In support of the genus-specific concept, only the sparrow P. rutilans developed an infection (Tung et al, 2007).…”

“…These authors put forward the concept of intra-familial specificity when they suggested that a new coccidian species should be compared in detail with the coccidian species that is most structurally similar to it within the same host family. However, Tung et al (2007) considered that this concept should be genus-specific based on data from studies of experimental infection. In these experiments, oöcysts of I. michaelbakeri Grulet, Landau & Baccam, 1982, a parasite of the sparrow Passer rutilans (Temminck), were used to inoculate their natural host and the following birds: the estrildids passerines Lonchura punctulata (L.) and Padda oryzivora (L.); the fringillid passerine Serinus canaria; the galliform Gallus gallus (L.); and the anseriform Anas platyrhynchos (L.).…”

Afternoon shedding of a new species ofIsospora(Apicomplexa) in the endangered Regent Honeyeater (Xanthomyza phrygia)

“…It has been experimentally documented that it represents an adaptive trait against desiccation and ultraviolet radiation (Martinaud et al 2009). Little information exists about the pathology caused by Isospora species in birds, despite significant impact of parasites on bird's fitness and reproductive success (Grulet et al 1986b;McGraw et al 2002;Hõrak et al 2004;Tung et al 2007). Avian Isospora prevalence surveys that do not take into account the diurnal periodicity of the oocyst shedding will lead to incorrect results (Filipiak et al 2009).…”

Investigation of systemic isosporosis outbreaks in an aviary of greenfinch (Carduelis chloris) and goldfinch (Carduelis carduelis) and a possible link with local wild sparrows (Passer domesticus)

“…A study of 12 species of Isospora found in sparrow showed that these species are considered highly specific because transmission of infection could not be repeated in several captive species . Another study of Isospora michaelbakeri from russet sparrows ( Passer rutilans ) showed that this species failed to infect spotted munias ( Lonchura punctulate ), canaries ( Serinus canaria ), Java sparrows ( Padda oryzivora ), chickens ( Gallus domesticus ) or ducks ( Anas platyrhynchos ) . Prevalence studies and case studies indicate that Isospora has a worldwide distribution, with a high prevalence (up to 90%) reported in greenfinches in Estonia, blackbirds ( Turdus merula ) in Germany, sparrows in Israel and a range of passerines in New Zealand …”