Xth ICT, August 2000

Effect of viable or dead Lactobacillus casei organisms administered orally to mice on resistance against Trichinella spiralis infection

¹ Departamento de Parasitología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala, Col. Santo Tomás México, D.F.
² CENID-Parasitología Veterinaria, INIFAP-SAGAR, km 11.5 carretera Cuemavaca-Cuautla, Jiutepec, Estado de Morelos, México.

^** Correspondence : C.R. Bautista-Garfias, CENID-Parasitología Veterinaria, Apartado postal 206, CIVAC 62500. Edo. de Morelos, México. Tel.:00 52 73 19 28 50 - Fax : 00 52 73 20 55 44 E-mail : bautir@pavet.inifap.conacyt.mx

Abstract

The capacity of viable, dead Lactobacillus casei and supernantant from L casei culture, administered by oral route, to induce resistance in mice against Trichinella spiralis infection was evaluated. The percentage of adult worm reduction in the intestine five days after T. spiralis infection as compared with the worm burden in the control group fluctuated between between 53.1 and 58 % in mice treated with viable L. casei, while reductions in animals treated with dead lactobacilli or supernatant from L. casei culture were of 44 and 32.5 % respectively. The percentage of larvae per gram of muscle tissue reductions, as compared with controls, obtained 30 days after infection ranged from 48.4 to 70.7 % in rodents which ingested viable L. casei compared with the percentage reductions of 6 5 .9 and 24 % obtained respectively in mice treated with dead lactobacilli or with L. casei supernatant. The protective response observed in the present study may be explained on the basis of 1) lactobacilli colonization of the intestine, 2) macrophage processing of dead lactobacilli in local immune tissues and presentation of L. casei antigens to Th 1 cells which, in turn, produced IL-2 to activate B cells and other T cells.