To cool or not to cool? Intestinal coccidians disrupt the behavioral hypothermia of lizards in response to tick infestation.

It is generally accepted that parasites exert negative effects on their hosts and that natural selection favors specific host responses that mitigate this impact. It is also known that some components of the host immune system often co-evolve with parasite antigens resulting in a host-parasite arms race. In addition to immunological components of the anti-parasitic response, host behavioral responses are also important in this arms race and natural selection may favor avoidance strategies that preclude contact with parasites, or shifts in the host's thermoregulatory strategy to combat active infections (e.g., behavioral fever). Ticks are widespread parasites with direct and indirect costs on their vertebrate hosts. Their saliva provokes hemolysis in the blood of their hosts and can transmit a plethora of tick-borne pathogens. We enquired whether tick infestation by Ixodes pacificus can provoke a thermoregulatory response in Sceloporus occidentalis. For this, we compared the thermoregulatory behavior of tick-infested lizards against tick-infested lizards co-infected with two different species of coccidians (Lankesterella occidentalis and Acroeimeria sceloporis). After this, lizards were kept in individual terraria with a basking spot and fed ad libitum. We found that tick-infested lizards sought cooler temperatures in proportion to their tick load, and this response was independent of the co-infection status by L. occidentalis. This was consistent in April and June (when tick loads were significantly lower) and suggests a conservative strategy to save energy which might have been selected to overcome tick infestations during phenological peaks of this parasite. However, this behavior was not observed in lizards co-infected with A. sceloporis, suggesting that co-infection with this intestinal parasite prompt lizards to be active. Cost of tick infestation was confirmed because housed lizards lost weight at a constant ratio to initial tick load, independently of other infections. The broader implications of these findings are discussed in the context of climate change.

Water-related parasitic diseases in China.

Water-related parasitic diseases are directly dependent on water bodies for their spread or as a habitat for indispensable intermediate or final hosts. Along with socioeconomic development and improvement of sanitation, overall prevalence is declining in the China. However, the heterogeneity in economic development and the inequity of access to public services result in considerable burden due to parasitic diseases in certain areas and populations across the country. In this review, we demonstrated three aspects of ten major water-related parasitic diseases, i.e., the biology and pathogenicity, epidemiology and recent advances in research in China. General measures for diseases control and special control strategies are summarized.

[Coccidia (Eimeriida) from fishes of the continental waters of Russia].

Data on the Coccidia parasitizing fishes of 12 orders (Acipenseriformes, Clupeiformes, Salmoniformes, Anguilliformes, Siluriformes, Atheriniformes, Gadiformes, Gasterosteiformes, Syngnatiformes, Mugiliformes, Scorpaeniformes, and Pleuronectiformes) are given. Authors and year of description, synonymy, morphofunctional organization of exogenic stages, and list of hosts are presented for each coccidian species.

Host specificity of Calyptospora funduli (Apicomplexa: Calyptosporidae) in atheriniform fishes.

Calyptospora funduli has a broad host specificity, infecting at least 7 natural and 10 additional experimental definitive hosts, all atheriniform fishes within 5 families, but most in the genus Fundulus. Barriers, apparently innate ones, prevent any development of C. funduli in perciform fishes but allow incomplete or abnormal development of the parasite in a few unnatural atheriniform hosts. In the freshwater species Fundulus olivaceus and Fundulus notti, these abnormalities consisted of asynchronous development, degeneration of the parasite in early stages of development, and the formation of numerous macrophage aggregates. Rivulus marmoratus has the ability to eliminate infections with a granulomatous inflammatory response. Additional barriers that limit natural infections of C. funduli in other hosts include feeding behavior, environmental conditions, and geographic isolation.

Experimental modes of Caryospora bigenetica (Apicomplexa: Eimeriidae) infection in swine and the effects of temperature and salinity on parasite infectivity in porcine tissue.

Four crossbred pigs (Sus scrofa) were inoculated orally with Caryospora bigenetica oocysts derived from snake and mouse feces, and with C. bigenetica infected mouse tissue. One pig also was given i.m. injections of methylprednisolone acetate. All four pigs displayed clinical signs including erythema, edema, and lethargy. Caryocysts were observed histologically in numerous tissues including ear, tongue, jowl, shoulder, loin, intercostal, ham, hock, and feet. The four pigs each were butchered into six commercial cuts: shoulder, loin, side, ham, hock, and feet. Raw 10 g samples from each cut were bioassayed by pepsin digestion and s.c. inoculation into 12 Swiss-Webster mice (Mus musculus) and 12 cotton rats (Sigmodon hispidus). Seventeen of 24 mice and cotton rats exhibited clinical signs and C. bigenetica tissue infections. Remaining portions of the six commercial cuts were temperature or saline treated, and 10 g samples were bioassayed in 16 mice and 12 cotton rats. No clinical sign or tissue infection was observed in these animals. Our study presents evidence that swine can be infected with C. bigenetica by ingesting oocysts present in snake feces or mouse feces (following inoculation of mice with snake-derived oocysts) or by ingesting C. bigenetica infected rodent tissue, that endogenously produced C. bigenetica oocysts are not excreted in the feces of swine, and that C. bigenetica in pork can be rendered noninfective by freezing at -20 degrees C (-4 degrees F) for 21 days, frying at 84 degrees C (183 degrees F) for 17 min, microwaving at 88 degrees C (190 degrees F) for 17 min, grilling at 82 degrees C (180 degrees F) for 48 min, baking at 95 degrees C (203 degrees F) for 230 min, boiling at 100 degrees C (212 degrees F) for 60 min, or by curing at 4 degrees C (39 degrees F) for 20 days.

Investigation of transplacental transmission of Caryospora bigenetica (Apicomplexa: Eimeriidae) in mice.

Five pairs of female Swiss-Webster mice were caged with 5 males (2 females/1 male). Eight females were inoculated orally with 2.6 x 10(5) Caryospora bigenetica oocysts either 3 days before mating, 3 days after mating (PMD), 9 PMD, or 16 PMD. The remaining 2 females were inoculated orally with Hanks' balanced salt solution and served as controls. One female from each cage delivered naturally at full term and the second female delivered by cesarean section on postmating day 18. The number of offspring per litter ranged from 7 to 12. One female produced a litter of 3 stillborn and 5 liveborn offspring. Seven of 8 female mice exhibited swollen muzzles and footpads 8 days after inoculation. Caryospora bigenetica was identified in tissues of muzzle, tongue, footpad, uterus, and placenta at necropsy. This is the first report of C. bigenetica in uterus and placenta. Clinical signs and tissue infections were not observed in control mice or in any offspring of the 10 female mice. This study presents evidence that C. bigenetica is not transmitted transplacentally.