CENID Microbiología-INIFAP, México
Campo Experimental Pichucalco-INIFAP, México

Use of polymerase chain reaction for the identification of Leptospira sp. in urine of carriers

Dr. Víctor Manuel Banda Ruiz,¹ Dra. Laura Elena Orozco Vega² y Téc. Rosa María Urrutia Velázquez³

Summary

The objectives of the present work were to detect Leptospira seropositive animals. The ELISA results report only IgG antibodies, which could be attributable to chronic infections or else, that they are healthy carriers. All polymerase chain reaction positive animals should be considered potential sources of infection.

Key words: Leptospira, PCR, ELISA, healthy carrier.

From a previous study in Chiapas state, 81.8 % of the animals with known reproductive problems, were positive for Leptospira at the microagglutination test (AM).¹ The objectives of the present work were a) to detect Leptospira seropositive animals and b) those which eliminated the rickettsia in the urine in Chiapas State.

In the present study, 316 bovine females in milking stage, were used, the animals were bled from the jugular vein and the serum was tested by the ELISA for the presence of antibodies anti-leptospira. For this test, antigen from the Leptospira interrogans serovar hardjo strain hardjoprajitmo, was used to detect IgG. In order to determine the cutoff a positive serum to AM, ELISA and PCR (in urine); all positive and transition animals were sampled for urine and, which was analyzed by PCR, to identify those eliminating Leptospira sp in urine. All during the development of the study productive and reproductive record were taken of each animal in study.

Of the analysis of serum samples by the ELISA, globally 40.8 % of positive animals at a optic density (OD) greater to 1,0 and 20.1 % in transition with DO between 0.900 and 0.700. With regards to PCR only 13.1 % of animals eliminated the rickettsia in the urine (Table).

The main reproductive problems in ELISA reactors were: abortion (3.4 %), placental retention (2.2 %) and subclinical mastitis (1.7 %), the 92,7 % remainder did not show any specific problem.

The ELISA results report only IgG antibodies, which could be attributable to chronic infections or else, that they healthy carriers. All PCR positive animals should be considered potential sources of infection.

Uso de la reacción en cadena de la polimerasa para la identificación de Leptospira sp. en orina de portadores

Resumen

Se trazó como objetivo detectar los animales seropositivos a Leptospira. Los resultados del ELISA reportaron solo anticuerpos IgG, lo cual puede atribuirse a infecciones crónicas o bien a que sean portadores saludables. Todos los animales positivos a la reacción en cadena de la polimerasa deben considerarse fuentes potenciales de infección.

Palabras clave: Leptospira, RCP, ELISA, portador sano.

References

1. Orozco VLE, Alvarado IA, López FR, Mejía SP, Quiroz VJ, Gónzalez HM. Enfermedades y factores de riesgo relacionados con problemas reproductivos en bovinos de Chiapas. México: I Congreso Internacional de Investigación y Transferencia de Tecnología Agropecuaria Chiapas 2002 Tuxtla Gutiérrez; 2002. p.108.

Recibido: 27 de diciembre de 2004. Aprobado: 10 de marzo de 2005.
Dr. Víctor Manuel Banda Ruiz. CENID Microbiología-INIFAP, México. Correo electrónico: leorozco@yahoo.com.mx

¹ Maestro en Ciencias. CENID Microbiología-INIFAP, México.
² Maestra en Ciencias. Campo Experimental Pichucalco-INIFAP, México.
³ Técnico. Campo Experimental Pichucalco-INIFAP, México.