Indirect Hemagglutination Test in the Detection of Antibodies against Toxoplasma gondii in Venezuelan Felids / Prueba de hemaglutinación indirecta en la detección de anticuerpos contra Toxoplasma gondii en félidos venezolanos

Abstract Current knowledge of Toxoplasma gondii infection in Venezuelan ecosystems is limited. Mammals and birds are intermediate hosts, and felid species are definitive hosts. In most human-altered habitats, the domestic cat is the predominant definitive host. Cats are important in the epidemiology of T. gondii infection because they are the only hosts that can excrete environmentally resistant oocysts. Other carnivores can be infected consuming tissue cysts when feeding on infected animals and by incidental ingestion of oocysts from environmental contamination. This study aimed to quantify the values of antibodies for T. gondii in blood serum of some felids' species employing the technique of indirect hemagglutination. In the present study, seropositivity of T. gondii was determined in serum of 35 animals (22 stray cats and 13 wild cats) from Venezuela, South America. Antibodies to T. gondii were found in 21 of 22 (95.45 %) stray cats' titers of 1:64 in four, 1:128 in four, 1:256 in one, 1:512 in one, 1:1024 in three, and 1:2048 or higher in eight. In four of six (66.67 %) ocelots' titers of 1:64 in one, 1:256 in one, 1:1024 in one, and one with titers 1:2048. In three of four (75.00 %) jaguars' titers of 1:512 in one, and two with titers 1:2048. The Kruskal-Wallis test showed a statistically significant difference between species (H = 8.413, p = 0 .015).

Resumen El conocimiento actual de la infección por Toxoplasma gondii en los ecosistemas venezolanos es limitado. Los mamíferos y las aves son hospedadores intermedios y los félidos son hospedadores definitivos. En la mayoría de los hábitats alterados por el hombre, el gato doméstico es el hospedador definitivo predominante. Los gatos son importantes en la epidemiología de la infección por T. gondii porque son los únicos hospedadores que pueden excretar los ooquistes resistentes al medio ambiente. Otros carnívoros pueden infectarse por el consumo de quistes tisulares al alimentarse de animales infectados y por la ingestión incidental de ooquistes procedentes de la contaminación ambiental. Este estudio tuvo como objetivo cuantificar los valores de anticuerpos para T. gondii en el suero sanguíneo de algunas especies de félidos mediante la técnica de hemoaglutinación indirecta. En el presente estudio se determinó la seropositividad de T. gondii en el suero de 35 animales (22 gatos callejeros y 13 felinos silvestres) de Venezuela, Sudamérica. Los anticuerpos contra T. gondii se encontraron en 21 de 22 (95,45 %) gatos callejeros con títulos de 1:64 en cuatro, 1:128 en cuatro, 1:256 en uno, 1:512 en uno, 1:1024 en tres y 1:2048 o más en ocho. En cuatro de seis (66,67 %) ocelotes con títulos de 1:64 en uno, 1:256 en uno, 1:1024 en uno, y uno con títulos 1:2048. En 3 de 4 (75,00 %) jaguares con títulos de 1:512 en uno, y dos con títulos 1:2048. La prueba de Kruskal-Wallis mostró una diferencia estadísticamente significativa entre las especies (H = 8,413, p = 0,015).

First molecular detection of Trypanosoma cruzi, T. rangeli and Leishmania spp. in capybaras.

Hydrochoerus hydrochaeris (capybara), is a widely distributed rodent in Latin America, with exploitation for food purposes and also used in leather industry products. The infection of this rodent by trypanosomatids may not be detected by parasitological methods, due to low parasitemias. The Capybaras blood samples from the Apure State were collected on filter paper, DNA was extracted and PCR was performed. The PCR technique was used for the detection of Trypanosoma cruzi satellite and kinetoplast DNA, T. rangeli miniexon, T. evansi RIME sequence, and DNA encoding ribosomal RNA and internal transcribed spacer 1 from Leishmania spp. Of the 16 evaluated samples, 12 (75%) were positive for T. cruzi, two for T. rangeli (12.5%), one for Leishmania spp. (6.3%) and none for T. evansi. Regarding coinfection, the two specimens infected with T. rangeli were also infected with T. cruzi (12.5%) and the positive sample for Leishmania spp. was also infected with T. cruzi (6.3%). The results shown in this study represent the first finding of T. cruzi infection, detected by molecular methods, world-wide and the first time that T. rangeli and Leishmania spp. have been found in capybaras. In addition, we report coinfections by T. cruzi/T. rangeli and T. cruzi/Leishmania spp. in H. hydrochaeris for the first time world-wide. Capybaras are widely managed as a source of animal protein, the results obtained require evaluating their possible role as a reservoir in trypanosomiasis and leishmaniasis. A 'One Health' approach through combination of ecological, veterinary and human health including the diagnosis and treatment of diseases of both humans and animals is essential for the development of more successful health programs.

Diminutive, degraded but dissimilar: Wolbachia genomes from filarial nematodes do not conform to a single paradigm.

Wolbachia are alpha-proteobacteria symbionts infecting a large range of arthropod species and two different families of nematodes. Interestingly, these endosymbionts are able to induce diverse phenotypes in their hosts: they are reproductive parasites within many arthropods, nutritional mutualists within some insects and obligate mutualists within their filarial nematode hosts. Defining Wolbachia 'species' is controversial and so they are commonly classified into 17 different phylogenetic lineages, termed supergroups, named A-F, H-Q and S. However, available genomic data remain limited and not representative of the full Wolbachia diversity; indeed, of the 24 complete genomes and 55 draft genomes of Wolbachia available to date, 84 % belong to supergroups A and B, exclusively composed of Wolbachia from arthropods. For the current study, we took advantage of a recently developed DNA-enrichment method to produce four complete genomes and two draft genomes of Wolbachia from filarial nematodes. Two complete genomes, wCtub and wDcau, are the smallest Wolbachia genomes sequenced to date (863 988 bp and 863 427 bp, respectively), as well as the first genomes representing supergroup J. These genomes confirm the validity of this supergroup, a controversial clade due to weaknesses of the multilocus sequence typing approach. We also produced the first draft Wolbachia genome from a supergroup F filarial nematode representative (wMhie), two genomes from supergroup D (wLsig and wLbra) and the complete genome of wDimm from supergroup C. Our new data confirm the paradigm of smaller Wolbachia genomes from filarial nematodes containing low levels of transposable elements and the absence of intact bacteriophage sequences, unlike many Wolbachia from arthropods, where both are more abundant. However, we observe differences among the Wolbachia genomes from filarial nematodes: no global co-evolutionary pattern, strong synteny between supergroup C and supergroup J Wolbachia, and more transposable elements observed in supergroup D Wolbachia compared to the other supergroups. Metabolic pathway analysis indicates several highly conserved pathways (haem and nucleotide biosynthesis, for example) as opposed to more variable pathways, such as vitamin B biosynthesis, which might be specific to certain host-symbiont associations. Overall, there appears to be no single Wolbachia-filarial nematode pattern of co-evolution or symbiotic relationship.

Inmovilización química, hematología y química sanguínea de jaguares (Panthera onca) en zoológicos de Venezuela: estudio retrospectivo, 1996-2009 / Chemical immobilization, hematology, and blood chemistry in jaguars (Panthera onca) in Venezuelan zoos: A retrospective study, 1996-2009 / Imobilização química, hematologia e química sanguínea de onças-pintadas (Panthera onca) em zoológicos de Venezuela: estudo retrospectivo, 1996-2009

Resumen Veintidós jaguares (Panthera onca) (12 machos y 10 hembras) mantenidos en cautiverio entre 1996 y 2009, con edades de entre 3 y 17 años y con una variación de peso entre 40 y 87 kg, fueron inmovilizados químicamente con una combinación de ketamina (100 mg/ml)-xilacina (100 mg/ml) a una dosis constante de 4,0-2,0 mg/kg, respectivamente. El tiempo del efecto inicial varió de 9 a 55 min, y el tiempo de recumbencia lateral o esternal varió de 25 a 155 min. Todos los jaguares inmovilizados mostraron buen relajamiento muscular. Se observó salivación y arqueos en nueve de los jaguares. El vómito se presentó en cuatro animales. Generalmente, la inducción anestésica con la combinación de ketamina-xilacina fue rápida y suave; el tiempo de recuperación osciló de 2 a 35 min. La verificación continua de la frecuencia cardíaca, la frecuencia respiratoria y la temperatura corporal no indica respuestas fisiológicas adversas a esta combinación de fármacos. Todos los jaguares parecían normales y regresaban a sus actividades después de la recuperación.

Abstract Twenty-two jaguars (Panthera onca) (12 males and 10 females) kept in captivity between 1996 and 2009, between 3 and 17 years of age, and with a weight variation between 40 and 87 kg, were chemically immobilized with a combination of ketamine (100 mg/ml)-xylazine (100 mg/ml) at a constant dose of 4.0-2.0 mg/kg, respectively. Initial effect time varied from 9 to 55 min, and lateral or sternal recumbency time varied from 25 to 155 min. All the immobilized jaguars showed good muscle relaxation. Salivation and arching were observed in nine jaguars. Four animals presented with vomiting. Generally, anesthetic induction with the combination of ketamine-xylazine was quick and smooth; recovery time ranged from 2 to 35 min. The continuous monitoring of heart rate, respiratory rate, and body temperature did not indicate adverse physiological responses to this combination of drugs. All the jaguars seemed normal and returned to their activities after recovery.

Resumo Vinte e duas onças-pintadas (Panthera onca) (12 machos e 10 fêmeas) mantidos em cativeiro entre 1996 e 2009, com idades entre 3 e 17 anos e com variação de peso entre 40 e 87 kg, foram quimicamente imobilizadas com uma combinação de cetamina (100 mg/ml)-xilacina (100 mg/ml) em una dose constante de 4,0-2,0 mg/kg, respetivamente. O tempo de efeito inicial variou de 9 a 55 min, e o tempo de decúbito lateral ou esternal variou de 25 a 155 min. Todas as onças-pintadas imobilizadas mostraram bom relaxamento muscular. Observou-se salivação e arcos em nove dos jaguares. Vómitos ocorreram em quatro animais. Geralmente, a indução anestésica com a combinação de cetamina-xilacina foi rápida e suave. O tempo de recuperação oscilou de 2 a 35 min. A verificação continua da frequência cardíaca, frequência respiratória e temperatura corporal não indica respostas fisiológicas adversas a esta combinação de fármacos. Todos os jaguares pareciam normais e voltaram a suas atividades após da recuperação.

Shaking the Tree: Multi-locus Sequence Typing Usurps Current Onchocercid (Filarial Nematode) Phylogeny.

During the past twenty years, a number of molecular analyses have been performed to determine the evolutionary relationships of Onchocercidae, a family of filarial nematodes encompassing several species of medical or veterinary importance. However, opportunities for broad taxonomic sampling have been scarce, and analyses were based mainly on 12S rDNA and coxI gene sequences. While being suitable for species differentiation, these mitochondrial genes cannot be used to infer phylogenetic hypotheses at higher taxonomic levels. In the present study, 48 species, representing seven of eight subfamilies within the Onchocercidae, were sampled and sequences of seven gene loci (nuclear and mitochondrial) analysed, resulting in the hitherto largest molecular phylogenetic investigation into this family. Although our data support the current hypothesis that the Oswaldofilariinae, Waltonellinae and Icosiellinae subfamilies separated early from the remaining onchocercids, Setariinae was recovered as a well separated clade. Dirofilaria, Loxodontofilaria and Onchocerca constituted a strongly supported clade despite belonging to different subfamilies (Onchocercinae and Dirofilariinae). Finally, the separation between Splendidofilariinae, Dirofilariinae and Onchocercinae will have to be reconsidered.

Isolation and molecular identification of Leishmania chagasi from a bat (Carollia perspicillata) in northeastern Venezuela.

This report describes the isolation of a Leishmania chagasi strain from a bat (Carollia perspicillata), and its identification using biological methods and molecular characterization. The parasites were isolated in an artificial culture medium from a blood sample extracted from a bat heart. The isolate was then inoculated into the footpads of Balb/c mice, which subsequently developed a typical nodular leishmanial lesion; the parasites were confirmed as Leishmania by smear and histopathology. Molecular characterization of the parasites was performed by polymerase chain reaction with species-specific primers, kDNA restriction pattern following Hae III endonuclease digestion and dot blot hybridization using a kDNA probe. This report demonstrates that bats can be hosts for L. chagasi species and suggests the need for studies to determine whether they may be involved in foci of visceral leishmaniasis.

Isolation and molecular identification of Leishmania chagasi from a bat (Carollia perspicillata) in northeastern Venezuela

This report describes the isolation of a Leishmania chagasi strain from a bat (Carollia perspicillata), and its identification using biological methods and molecular characterization. The parasites were isolated in an artificial culture medium from a blood sample extracted from a bat heart. The isolate was then inoculated into the footpads of Balb/c mice, which subsequently developed a typical nodular leishmanial lesion; the parasites were confirmed as Leishmania by smear and histopathology. Molecular characterization of the parasites was performed by polymerase chain reaction with species-specific primers, kDNA restriction pattern following Hae III endonuclease digestion and dot blot hybridization using a kDNA probe. This report demonstrates that bats can be hosts for L. chagasi species and suggests the need for studies to determine whether they may be involved in foci of visceral leishmaniasis.