The chromosomal DNA of spirochetes isolated from human, swine, dog, mouse, rat, and chicken intestine or feces was subjected to restriction enzyme analysis and hybridization with three different DNA probes, derived from a flagellin gene, a hemolysin gene, and the 16S rDNA sequence of the pathogenic swine intestinal spirochete Serpulina hyodysenteriae. This genetic analysis showed that intestina...

Recent models of ecological parapatry, where the geographical distributions of two similar species abut without overlapping, have shown that spatial gradients in intrinsic growth rates can lead to sharp boundaries when dispersal is density dependent. However, a well documented parapatric boundary in southern Australia between two tick species that parasitise a large lizard lacks one or both of ...

Zoonotic pathogens often infect several animal species, and gene flow among populations infecting different host species may affect the biological traits of the pathogen including host specificity, transmissibility and virulence. The bacterium Campylobacter jejuni is a widespread zoonotic multihost pathogen, which frequently causes gastroenteritis in humans. Poultry products are important trans...

When every individual has an equal chance of mating with other individuals, the population is classified as panmictic. Amongst metazoan parasites of animals, local-scale panmixia can be disrupted due to not only non-random mating, but also non-random transmission among individual hosts of a single host population or non-random transmission among sympatric host species. Population genetics theor...

In most aquatic ecosystems, fishes are hosts to parasites and, sometimes, these parasites can affect fish biology. Some of the most dramatic cases occur when fishes are intermediate hosts for larval parasites. For example, fishes in southern California estuaries are host to many parasites. The most common of these parasites, Euhaplorchis californiensis, infects the brain of the killifish Fundul...

Climate warming is predicted to increase the frequency of invasions by pathogens and to cause the large-scale redistribution of native host species, with dramatic consequences on the health of domesticated and wild populations of plants and animals. The study of historic range shifts in response to climate change, such as during interglacial cycles, can help in the prediction of the routes and ...

a total of 3528 specimens of freshwater turtles belonging to two families viz., geoemydidae (brown river turtle, kachuga smithi; indian saw-backed turtle, k. tecta; brahminy rrive turtle, hardella thurgi; spotted pond turtle, geoclemys hamiltonii) and trionychidae (indian soft-shell turtle, aspederates gangeticus; peacock soft-shell turtle, a.hurum; narrow-headed soft-shell turtle, chitra indic...

In the present study, six species of Bipolaris viz. B. heveae, B. neergaardii, B. papendrofii, B. zeae, B. oryzae, and B. australiensis and two species of Curvularia viz. C. intermedia and C. heteropogonicola were identified on graminicolous species. Bipolaris heveae on Echinochloa sp., Cynodon dactylon and Arundo sp., B. neergaardii on Oryza sativa, B. papendrofii on Saccharum officinarum and ...

The fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis, has been linked to catastrophic amphibian declines throughout the world. Amphibians differ in their vulnerability to chytridiomycosis; some species experience epizootics followed by collapse while others exhibit stable host/pathogen dynamics where most amphibian hosts survive in the presence of B...

Some hosts harbor diverse parasite communities, whereas others are relatively parasite free. Many factors have been proposed to account for patterns of parasite species richness, but few studies have investigated competing hypotheses among multiple parasite communities in the same host clade. We used a comparative data set of 941 host-parasite combinations, representing 101 anthropoid primate s...