Innate and adaptive immune response of Rainbow trout (Oncorhynchus mykiss) naturally infected with Yersinia ruckeri.

Rainbow trout is an important fish species for Peruvian artisanal aquaculture, comprising over 60% of the total aquaculture production. However, their industry has been highly affected by several bacterial agents such as Yersinia ruckeri. This pathogen is the causative agent of Enteric Redmouth Disease, and causes high mortality in fingerlings and chronic infection in adult rainbow trout. To date, the immune response of rainbow trout against Y. ruckeri has been well studied in laboratory-controlled infection studies (i.e. intraperitoneal infection, bath immersion), however, ,the immune response during natural infection has not been explored. To address this, in this study, 35 clinically healthy O. mykiss without evidence of lesions or changes in behavior and 32 rainbow trout naturally infected by Y. ruckeri, were collected from semi-intensive fish farms located in the Central Highlands of Peru. To evaluate the effect on the immune response, RT-qPCR, western blotting, and ELISA were conducted using head kidney, spleen, and skin tissues to evaluate the relative gene expression and protein levels. Our results show a significant increase in the expression of the pro-inflammatory cytokines il1b, tnfa, and il6, as well as ifng in all three tissues, as well as increases in IL-1ß and IFN-γ protein levels. The endogenous pathway of antigen presentation showed to play a key role in defense against Y. ruckeri, due to the upregulation of mhc-I, tapasin, and b2m transcripts, and the significant increase of Tapasin protein levels in infected rainbow trout. None of the genes associated with the exogenous pathway of antigen presentation showed a significant increase in infected fish, suggesting that this pathway is not involved in the response against this intracellular pathogen. Finally, the transcripts of immunoglobulins IgM and IgT did not show a modulation, nor were the protein levels evaluated in this study.

Environmental and individual determinants of fecal avoidance in semi-free ranging woolly monkeys (Lagothrix lagotricha poeppigii).

OBJECTIVES: Parasite selection pressures have driven the evolution of numerous behavioral defenses in host species, but recent studies revealed individual variation in their expression. As little is known about the factors causing heterogeneity among individuals in infection-avoidance behaviors, we investigated in woolly monkeys (Lagothrix lagotricha poeppigii) the influence of several environmental and individual characteristics on the tendency to avoid food contaminated by soil and by their own and conspecifics' feces. MATERIALS AND METHODS: We conducted feeding tests on 40 semi-free ranging individuals rescued from the pet trade. Using generalized linear mixed models, we investigated the effect of season, sex, age, dominance rank, and exposure to non-natural living conditions on feeding decisions. RESULTS: Woolly monkeys did not avoid soil-contaminated food and equally avoided food contaminated by their own and conspecifics' feces. Individuals varied greatly in their level of fecal avoidance. Only females exhibited strong avoidance of fecally contaminated food, but adapted their behavior to food availability, highlighting the trade-off between nutritional intake and parasite avoidance. Additionally, low-ranking females, less competitive over food resources, exhibited lower avoidance than dominant ones. Juveniles were more cautious than adults, possibly to compensate for a higher parasite susceptibility. Finally, we reported an unknown effect of exposure to non-natural living conditions on behavioral defenses, as animals kept as household pets for an extended period apparently lost their ability to avoid fecally contaminated food. CONCLUSION: We argue that striving to understand variation in infection-avoidance behaviors in natural populations is crucial to predict disease spread and inform conservation policies.

Draft Genome Sequence of Aeromonas sobria Strain CHT-30, Isolated from a Diseased Rainbow Trout (Oncorhynchus mykiss) in Peru.

The Gram-negative bacterium Aeromonas sobria is an opportunistic pathogen that affects humans and animals, including fish. Here, we report the draft genome of strain CHT-30, which was isolated from a diseased rainbow trout in Peru. The genome size is 4.91 Mb, with a G+C content of 57.7%, and the genome includes 4,820 coding sequences.

Local regulation of immune genes in rainbow trout (Oncorhynchus mykiss) naturally infected with Flavobacterium psychrophilum.

Flavobacterium psychrophilum is the etiological agent of bacterial cold water disease (BCWD), also referred to as rainbow trout fry syndrome (RTFS), a disease with great economic impact in salmonid aquaculture. Despite this, to date, not many studies have analyzed in depth how the immune system is regulated during the course of the disease. In the current study, we have studied the transcription of several immune genes related to T and B cell activity in the skin of rainbow trout (Oncorhynchus mykiss) naturally infected with F. psychrophilum in a farm located in Lake Titicaca (Peru). The levels of expression of these genes were tested and compared to those obtained in asymptomatic and apparently healthy rainbow trout. In the case of symptomatic fish, skin samples containing characteristic ulcerative lesions were taken, as well as skin samples with no lesions. Our results pointed to a significant local up-regulation of IgD, CD4, CD8, perforin and IFNγ within the ulcerative lesions. On the other hand, no differences between the levels of expression of these genes were visible in the spleen. To confirm these results, the distribution of IgD+ and CD3+ cells was studied through immunohistochemical techniques in the ulcerative lesions. Our results demonstrate a strong local response to F. psychrophilum in rainbow trout in which IgD and T cells seem to play a major role.

Parásitos gastrointestinales en cachorros caninos provenientes de la venta comercial en el Cercado de Lima / Gastrointestinal parasites in canine puppies for commercial sale in Lima downtown

Determinar la frecuencia de parásitos gastrointestinales en caninos menores de seis meses de edad provenientes de la venta comercial. También determinar si las variables raza, sexo y edad están asociadas a la presentación de cuadros de parasitosis. Metodología: Se recolectaron 97 muestras de heces de mascotas caninas que se comercializan en el cercado de Lima, las cuales fueron procesados mediante las técnicas de examen directo, de concentración por flotación, de concentración por sedimentación y de Ziehl Neelsen, considerándose positivas las muestras con presencia de huevos de parásito o parásitos bajo el microscopio. Resultados y Conclusiones: El 100% de las muestras analizadas fueron positivas a la presencia de parásitos. Las mayores frecuencias fueron del nemátode Toxocara canis fue (87.96%) y del protozoario Isospora canis (98.78%) ; los mismos como asociación biparasitaria (62.89%) y monoparasitarias Toxocara canis (17.56%); por primera vez se encontró una asociación de triprarasitismo de Toxocara canis - Isospora canis - Toxascaris leonina (12.37%). En los machos hubo una mayor presentación de parasitosis (57.7%) que en las hembras (42.3%). Caninos de raza pura tuvieron mayor frecuencia de presentación de parasitosis (82.5%); La edad no presentó diferencias estadísticas en los tres estratos estudiados, dándose en el estrato de mayor o igual que 8 y < 12 semanas representados por el 41.2% de casos. La parasitosis en caninos evaluados es del 100%, siendo Toxocara canis el más frecuente...

To determine the frequency of gastrointestinal parasites in canines younger that 6 months for commercial sale in Lima downtown. Methods: 97 dog fecal samples were analyzed using the techniques of direct examination, concentration by flotation, by sedimentation and Ziehl Neelsen, it was considered a positive sample the presence of parasites or parasite eggs under the microscope. Results and Conclusions: 100% of the samples tested were positive for the presence of eggs or parasites, where the nematode Toxocara canis (87.96%) and the protozoan Isospora canis (98.78%) were found more frequently; and both of them as biparasitism association (62.89%). Toxocara canis monoparasitism in (17.56%). Toxocara canis - Isospora canis - Toxascaris leonina (12.37%) triprarasitism association was found. In males there was a greater presence of parasites (57.7%) than females (42.3%). Pure breed had higher frequency of parasites (82.5%); Age does not show statistical differences in the three strata studied. 41.2% of cases were in the range of greater than or equal 8 and <12 weeks of age. The parasitism in the studied dogs is 100%, being the most common Toxocara canis...

Toxoplasma gondii and Neospora caninum seroprevalences in domestic South American camelids of the Peruvian Andes.

The objective of this study was to investigate the presence of Toxoplasma gondii- and Neospora caninum-specific antibodies in domestic South American camelids (SAC) (llamas and alpacas) from the Peruvian Andes through a cross-sectional study. A wide panel of serum samples collected from 1,845 llamas and 2,874 alpacas from the two main SAC production areas of Peru was selected. Immunofluorescence antibody technique was employed to detect and titrate specific anti-T. gondii and anti-N. caninum immunoglobulins G in serum samples. The association between T. gondii and N. caninum seroprevalence and the geographical origin (Central and South Peruvian Andes) was evaluated. Anti-T. gondii antibodies were found in 460 (24.9 %) llamas and 706 (24.6 %) alpacas, whereas anti-N. caninum antibodies were detected in 153 (8.3 %) llamas and 425 (14.8 %) alpacas. Toxoplasma gondii infection was strongly associated with the South Peruvian Andes where moderate climate conditions, larger human population, compared to the Central region, and the presence of wildlife definitive hosts could favor horizontal transmission to SAC. In contrast, N. caninum infection was not associated with the geographical region. These results indicate that T. gondii and N. caninum infections are highly and moderately widespread, respectively, in both species of domestic SAC studied in the sampled areas and appropriate control measures should be undertaken to reduce the prevalence of both parasitic infections.

Primer reporte de Neospora caninum, en caballos de carrera de Lima, Perú / First report of Neospora caninum, in race horse from Lima, Peru

Determinar la exposición de los caballos de carrera al N. caninum, mediante la detección de anticuerpos séricos. Material y Método: Se evaluaron 163 sueros de caballos procedentes del Hipódromo de Monterrico, Lima, los cuales fueron procesados mediante el método de Inmunoflorescencia Indirecta, considerándose positivos aquellos animales cuyos sueros obtuvieron un título igual o mayor a 1:100. Se realizó la titulación del suero mediante diluciones seriadas hasta alcanzar una dilución negativa. Resultados: Se detectaron anticuerpos a N. caninum en el 12 % (19/163) de los caballos examinados, 21% presentaron títulos de 1/100, 1/800 y 1/1600, el 6% presentaron títulos de 1/200 y 1/400 y el 5% presentaron títulos de 1/3200. No se encontró asociación entre las variables sexo, edad y procedencia con la presencia de seroreactores frente a N. caninum. Conclusión: El presente estudio es el primero en confirmar la presencia de anticuerpos séricos a N. caninum en caballos de carrera de Perú...

Determine the exposure of N. caninum in racehorses with the detection of serum antibodies. Material and methods: We evaluated sera from 163 horses from the Hippodrome of Monterrico, Lima, which were processed using the indirect immunofluorescence method, considering positive animals whose sera obtained a degree equal to or greater than 1:100. Was performed by titrating the serum dilutions to reach a negative dilution. Results: Antibody to N. caninum in 12% (19/163) of the horses examined, 21% had titers of 1/100, 1/800 and 1/1600, 6% had titers of 1/200 and 1/400 and 5% had titers 1/3200. No association between sex, age and origin with the presentation seroreactors against N. caninum. Conclusions: The present study is the first to confirm the presence of serum antibodies to N. caninum in race horses from Peru...

Evaluación de la calidad lagrimal en el perro sin pelo del Perú mediante la técnica de tiempo de ruptura de la película lagrimal precorneal / Evaluation of tear quality of peruvian hairless dog through the use of the tear film break-up time

El presente estudio tuvo por objetivo evaluar la calidad lagrimal en el perro sin pelo del Perú mediante el uso de la prueba de tiempo de Ruptura de la película lagrimal precorneal (TRPLP). Material y métodos: El estudio se realizó en la ciudad de Lima entre los meses de Julio a Diciembre del año 2008. Se evaluaron 125 canes de diferentes edades, tamaños y de ambos sexos. Resultados: En los resultados de la prueba de TRPLP se observó un alto porcentaje de perros con mala calidad lagrimal: 94,4% (118/125) en el ojo derecho y el 92% (115/125) en el ojo izquierdo. No se encontró asociación entre el sexo, estrato etáreo y lado del ojo evaluado para la prueba de (TRPLP). Conclusión: Se concluye que existe un porcentaje elevado de perros sin pelo del Perú con una mala Calidad lagrimal...

The purpose of this study was to evaluate the tear quality of Peruvian hairless dog through the use of the tear film break up time (TFBUT). Material and methods: The study took place in Lima Between July 2008 and December 2008. Results: A total of 125 animals of different of poor quality: 94.4% (118/125) in the rigth eye and 92%(115/125) in the left eye and without significant difference due to sex, age and eye side evaluated. Conclusion: It is concluded that a high percentage of peruvian hairless dog a poor tear film quality...