title: In vitro ovicidal and cestocidal effects of toxins from Bacillus thuringiensis on the canine and human parasite Dipylidium caninum.
abstract: Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. This bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum). Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 μ g/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. The lethal concentration of toxins on eggs was 600 μ g/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. The motility was inhibited by 100% after 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. Thus, B. thuringiensis is proposed as a potential biological control agent against this zoonosis.
authors.affiliation: Centro de Investigaciones Biológicas, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, 62209 Cuernavaca, MOR, Mexico.
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Peña
authors.forename: Fortino Agustín
authors.initials: FA
authors.lastname: Aguilar Jiménez
authors.forename: Claudia
authors.initials: C
authors.lastname: Hallal-Calleros
authors.forename: Jorge
authors.initials: J
authors.lastname: Morales-Montor
authors.forename: Víctor Manuel
authors.initials: VM
authors.lastname: Hernández-Velázquez
authors.forename: Fernando Iván
authors.initials: FI
authors.lastname: Flores-Pérez
mesh_terms: D000818:Animals; D000923:Anticestodal Agents / Q000737:chemistry / Q000494:pharmacology*; D001413:Bacillus thuringiensis / Q000737:chemistry*; D001427:Bacterial Toxins / Q000737:chemistry / Q000494:pharmacology*; D002589:Cestoda / Q000378:metabolism*; D002590:Cestode Infections / Q000378:metabolism / Q000517:prevention & control; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008124:Locomotion / Q000187:drug effects; D010063:Ovum / Q000378:metabolism; D015047:Zoonoses / Q000469:parasitology
chemical_list: D000923:Anticestodal Agents; C049673:Bacillus thuringiensis ovicidal toxin; D001427:Bacterial Toxins