First histopathological study in kidneys of rodents naturally infected with Leptospira pathogenic species from Yucatan, Mexico.

OBJECTIVE: To report the renal histological lesions in synanthropic rodents, Mus musculus and Rattus rattus, naturally infected with Leptospira spp., captured in a rural community in Yucatan, Mexico. METHODS: Kidney samples of synanthropic rodents were collected from a rural community in Yucatan, Mexico. Polymerase chain reaction was used to detect Leptospira spp. infection. Tissue kidney was fixed in 10% buffered formalin, processed according to the usual techniques for paraffin inclusion, cut and stained with hematoxylin and eosin, and examined using a conventional electronic microscope. RESULTS: A total of 187 rodents were captured. Nine individuals (4.8%) were positive for Leptospira spp. in the molecular analysis. All renal lesions observed in the histopathological study had been reported previously for Leptospira spp. infection. CONCLUSIONS: The histopathological lesions are present in the kidneys, plus the results of the polymerase chain reaction confirm that these rodents are true carriers of Leptospira spp.

Parasitic Zoonoses in Humans and Their Dogs from a Rural Community of Tropical Mexico.

A cross-sectional study was made on 89 inhabitants and their dogs from a rural community of Yucatan, Mexico, to determine the serological prevalence of some zoonotic parasitic agents. Samples were taken to monitor the presence and intensity of infection with gastrointestinal parasites in dogs. In humans, the serological prevalence of T. canis, T. gondii, and T. spiralis was 29.2%, 91.0%, and 6.7%, respectively. No associations were found between positive cases and studied variables. From the total of blood samples taken from dogs, 87 (97.6%) were seropositive to T. gondii; only 52 viable fecal samples were collected from dogs of which 46.2% had the presence of gastrointestinal parasites with low to moderate intensity; from those, 12% had the presence of T. canis. This study demonstrates the presence of the studied zoonotic agents in the area particularly T. gondii which suggest a common source of infection in dogs and humans and a high number of oocyts present in the environment. Preventive measures must be designed towards good prophylactic practices in domestic and backyard animals (T. canis and T. spiralis). Contaminated sources with T. gondii (food and water) should be further investigated in order to design effective control measures.

An epidemiological study of intestinal parasites of dogs from Yucatan, Mexico, and their risk to public health.

The prevalence of intestinal parasites in dogs and factors associated were studied in a rural community of Yucatan (southern Mexico), with special attention to those gastrointestinal parasites potentially transmitted to man. One hundred thirty dogs from 91 households were studied. Fecal samples were processed by the centrifugation-flotation and the McMaster techniques. To determine factors associated with zoonotic parasites in dogs, univariate analysis was performed, using sex, age, and body condition as independent variables. Variables with p < 0.2 were analyzed by a logistic regression. Of 130 dogs, 104 were positive for the presence of intestinal parasites, representing a prevalence of 80%. Eggs of four species of helminths (Ancylostoma caninum, Thichuris vulpis, Toxocara canis, and Dipylidium caninum) and coccidian oocysts were detected. A. caninum was the most prevalent parasite (73.8%), followed by T. vulpis (25.4%), T. canis (6.2%), D. caninum (2.3%), and coccidian oocysts (2.3%). The majority of dogs were infected by only one species of parasite (70/130, 53.8%). Mixed infection caused by two or three zoonotic parasites were discovered in 21.3% (30/130) and 3.1% (4/130), respectively. A. caninum showed the highest egg output (42.3% of dogs had ≥ 500 eggs per gram). Factors associated with zoonotic parasites were age (<2 years old; odds ratio = 5.30, p = 0.029) and body condition (poor body condition; odds ratio = 6.69, p = 0.026). In conclusion, young dogs from rural Yucatan, Mexico, with poor body condition had a higher prevalence of intestinal zoonotic parasites as these factors were associated with a higher risk of becoming infected.

Caracterización antigénica de un virus de la bronquitis infecciosa, aislado en pollos de traspatio en Yucatán, México / Antigenic characterization of an infectious bronchitis virus isolated in backyard chicken in the state of Yucatan, Mexico

La producción animal de traspatio es una actividad tradicional en México, cuya finalidad es solucionar algunos problemas de la difícil situación económica de los campesinos. Los pollo son la especie más común en dicho sistema en Yucatán y son alimentados con subproductos, En estudios previos se encontró que las enfermedades respiratorias constituyen las más importantes en estos animales. En el presente estudio se obtuvo un aislamiento del virus de la bronquitis infecciosa en pollos de engorda introducidos al traspatio del poblado Sinanché, Yucatán, México; aquél se denominó SIN6. La caracterización antigénica de este aislamiento se realizó mediante la prueba de inhibición de la hemaglutinación, utilizando antígeno hemaglutinante producido a partir de 11 serotipos de referencia del virus de la bronquitis infecciosa (Massachusetts 41, Arkansas, Connecticut, Holte, CVL/9, 793/B, Holandés 274, Holandés 1466, Australiano "T", italiano 624, y Chileno 368), y antisueros contra estos serotipos y el Iowa 97; de este último no se logró obtener antígeno a pesar de repetidos intentos. El aislamiento SIN6 tuvo una relación antigénica baja con todos los serotipos de referencia, lo que indica que probablemente es un serotipo nuevo, aunque estudios de secuencia genética son necesarios para confirmarlo. El serotipo CVL/9 presentó una fuerte relación antigénica con todos los demás, esta circunstancia lo hace un candidato para la producción de una vacuna universal contra la bronquitis infecciosa

Identificación de granjas seropositivas a Mycoplasma hyopneumonie y exploración de potenciales factores de riesgo relacionados a su presentación en 33 granjas porcinas del estado de Yucatan, México / To identify forms seropositive to mycoplasma hyopneumonie and to investigate the potential risk factors on its presentation in 33 pig farms in the state of Yucatan, Mexico

Introducción. Dentro de los problema infecciosos más graves que afectan a la porcicultura intensiva en todo el mundo se encuentran los respiratorios, los cuales producen efectos adversos sobre la ganancia de peso, la eficiencia alimenticia y la mortalidad. El objetivo del estudio fue detectar la presencia de anticuerpos contra Mycoplasma hyopneumonie (M. hyopneumonie) en cerdos de engorda del estado de Yucatán, México. Material y métodos. Se realizó un estudio transversal en 33 granjas porcinas del estado de Yucatán. En cada granja se recolectó 14 muestras de sueros procedentes de cerdos de engorda (= 5 meses de edad) de líneas comerciales. Para la detección de anticuerpos contra M. hyopneumonie, se utilizó una prueba comercial de ELISA indirecta. En cada granja se aplicó un cuestionario para conocer potenciales factores que pudieran estar relacionados a la seropositividad. La seroprevalencia de M. hyopneumoie se estratificó en dos categorías (ó 30 por ciento) y (> 30 por ciento) y se utilizó la prueba de Ji cuadrada para explorar la asociación con variables contenidas en aspectos generales, de instalaciones y equipo, medidas zoosanitarias y manejo. Resultados. De las 33 granjas muestreadas, 31 (93.9 por ciento) tuvieron al menos un animal seropositivo a M. hyopneumonie. De los 462 sueros evaluados, 168 (36.4 por ciento) resultaron seropositivos. No se encontró asociación (p>0.05) entre las variables analizadas como potenciales factores de riesgo y las seroprevalencias a M. hyopneumonie. Conclusioens. La seropositividad a M. hyopneumonie se encuentra presente y ampliamente distribuida en las granjas porcinas estudiadas y que éstas realizan práctica de manejo que pueden favorecer la presencia o incremento de la seroprevalencia a M. hyopneumonie