Sigmodontinae rodents as hosts for larvae and nymphs of Ixodes loricatus Neumann, 1899 (Acari: Ixodidae)

Larvae and nymphs of Ixodes loricatus Neumann, 1899 ticks (confirmed by morphological characters and by comparison of 16S mitochondrial rDNA sequences) were collected from Sigmodontinae Wagner, rodents in central and northern Argentina and Uruguay. A total of 100 larvae and 38 nymphs of I. loricatus were collected on the genera Akodon Meyen (n = 36 individuals), Calomys Waterhouse (n = 2), Oligoryzomys Bang (n = 12), Oxymycterus Waterhouse (n = 9), and Scapteromys Waterhouse (n = 13). 72 larvae and 18 nymphs were collected on Akodon. Adults of I. loricatus were found in central Argentina and Uruguay on Didelphimorphia of the genera Didelphis Linnaeus and Lutreolina Thomas. Ixodes loricatus has been considered a species with strict total specificity to Didelphimorphia. Our results show that this statement may not be justified. Sigmodontinae rodents are sympatric and share habitats with the phylogenetically distant Didelphimorphia; infestation with I. loricatus seems to be its consequence. We tentatively consider I. loricatus moderately specific to Didelphimorphia.Centro de Estudios Parasitológicos y de Vectore

Sigmodontinae rodents as hosts for larvae and nymphs of Ixodes loricatus Neumann, 1899 (Acari: Ixodidae)

Larvae and nymphs of Ixodes loricatus Neumann, 1899 ticks (confirmed by morphological characters and by comparison of 16S mitochondrial rDNA sequences) were collected from Sigmodontinae Wagner, rodents in central and northern Argentina and Uruguay. A total of 100 larvae and 38 nymphs of I. loricatus were collected on the genera Akodon Meyen (n = 36 individuals), Calomys Waterhouse (n = 2), Oligoryzomys Bang (n = 12), Oxymycterus Waterhouse (n = 9), and Scapteromys Waterhouse (n = 13). 72 larvae and 18 nymphs were collected on Akodon. Adults of I. loricatus were found in central Argentina and Uruguay on Didelphimorphia of the genera Didelphis Linnaeus and Lutreolina Thomas. Ixodes loricatus has been considered a species with strict total specificity to Didelphimorphia. Our results show that this statement may not be justified. Sigmodontinae rodents are sympatric and share habitats with the phylogenetically distant Didelphimorphia; infestation with I. loricatus seems to be its consequence. We tentatively consider I. loricatus moderately specific to Didelphimorphia.Centro de Estudios Parasitológicos y de Vectore

Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species

PLAN DE ACCIÓN PARA LA CONSERVACIÓN DEL AGUARÁ GUAZÚ EN SANTA FE VERSIÓN 01 PERÍODO 2009 – 2014

El presente plan fue realizado usando de base los capítulos 1, 2, 3 y 4 del trabajo: Estado  de  conocimiento  y  conservación  del  aguará  guazú  (Chrysocyon  brachyurus)  en  la  provincia  de Santa Fe, Argentina. . Se tomó como base orientaciones generales de Margoluis y Salafsky (1998) y en la estructura general se siguió de modelo práctico a Jiménez Pérez (2006). Para asignar la prioridad se utilizaron las categorías desarrolladas por el Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (Baz Hughes, et al. 2006), estas son: Esencial: una actividad específica cuyo cumplimiento es necesario para evitar una declinación de las poblaciones que pueda llevar a la extinción de la especie en la naturaleza y/o en cautiverio. Alta: una actividad específica cuyo cumplimiento es necesario para evitar una declinación poblacional de más del 20% de una población en 20 años o menos. Media: una actividad específica cuyo cumplimiento es necesario para evitar una declinación poblacional de hasta el 20% de una población en 20 años o menos. Baja: una actividad específica cuyo cumplimiento es necesario para prevenir declinaciones poblacionales  locales o que se estima que dicha acción apenas tiene un pequeño impacto sobre las poblaciones en un área grande. Se trata de una planificación para cinco años pues la experiencia indica que a Santa Fe le falta mucho  trabajo  y experiencia para  fortalecer  su  forma de  ver  y de actuar en  la  recuperación de  las especies amenazadas.  Por ejemplo muchas de  las amenazas  indirectas (generadoras de amenazas directas) que afectan a esta especie son producto de  la  falta de coordinación, compromiso, metas y objetivos comunes entre  los profesionales de  la conservación, sea sociedad civil u organismos estatales. Es así como se pretende en un corto plazo y monitoreando constantemente, las acciones y sus resultados, lograr un plan a futuro de mediano y largo plazo.Fil: Biassati, R. Secreataría de Medio Ambiente de Santa Fe; ArgentinaFil: Larriera, Alejandro. Secretaría de Medio Ambiente de Santa Fe; ArgentinaFil: Mosso, E.. Secretaría de Medio Ambiente de Santa Fe; ArgentinaFil: Rozztti, J.C.. Secretaría de Medio Ambiente de Santa Fe; ArgentinaFil: Moggia, L.. Secretaría de Medio Ambiente, Santa Fe; ArgentinaFil: Pautasso, A.. Museo de Cs Naturales Florentino Ameghino; ArgentinaFil: Nebozuk, M. A.. Museo Provincial de Ciencias Naturales Ángel Gallardo; ArgentinaFil: Walker, C.. Universidad Nacional del Litoral; ArgentinaFil: Ramirez, C.. Universidad Nacional del Litoral; ArgentinaFil: Mirol, P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Raimondi, Vanina Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Beldomenico, Pablo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Ciencias Veterinarias del Litoral; Argentina. Laboratorio de Ecología de Enfermedades; ArgentinaFil: Eberhardt, María Ayelen Teresita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Ciencias Veterinarias del Litoral; Argentina. Laboratorio de Ecología de Enfermedades; ArgentinaFil: Manzzoli, D.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Ciencias Veterinarias del Litoral; Argentina. Laboratorio de Ecología de Enfermedades; ArgentinaFil: Correa, A.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Terragona, E.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Magni, C.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Alvarado, S.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Barengo, E.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentin

True versus False Parasite Interactions: A Robust Method to Take Risk Factors into Account and Its Application to Feline Viruses

International audienceBACKGROUND: Multiple infections are common in natural host populations and interspecific parasite interactions are therefore likely within a host individual. As they may seriously impact the circulation of certain parasites and the emergence and management of infectious diseases, their study is essential. In the field, detecting parasite interactions is rendered difficult by the fact that a large number of co-infected individuals may also be observed when two parasites share common risk factors. To correct for these "false interactions", methods accounting for parasite risk factors must be used. METHODOLOGY/PRINCIPAL FINDINGS: In the present paper we propose such a method for presence-absence data (i.e., serology). Our method enables the calculation of the expected frequencies of single and double infected individuals under the independence hypothesis, before comparing them to the observed ones using the chi-square statistic. The method is termed "the corrected chi-square." Its robustness was compared to a pre-existing method based on logistic regression and the corrected chi-square proved to be much more robust for small sample sizes. Since the logistic regression approach is easier to implement, we propose as a rule of thumb to use the latter when the ratio between the sample size and the number of parameters is above ten. Applied to serological data for four viruses infecting cats, the approach revealed pairwise interactions between the Feline Herpesvirus, Parvovirus and Calicivirus, whereas the infection by FIV, the feline equivalent of HIV, did not modify the risk of infection by any of these viruses. CONCLUSIONS/SIGNIFICANCE: This work therefore points out possible interactions that can be further investigated in experimental conditions and, by providing a user-friendly R program and a tutorial example, offers new opportunities for animal and human epidemiologists to detect interactions of interest in the field, a crucial step in the challenge of multiple infections