Interpretation of Results

1. Recovery index of infectant larvae (L3). This index is considered to be the relationship between the number of L3 larvae obtained, and the egg counts by gram of feces (eggs per gram [epg]) multiplied by 3. Significant differences between the recovery indices obtained from control and test coprocultures are calculated, to establish the possible action of probiotic bacteria on parasitic eggs or first larval stages.

2. Dead L3 larvae number. Compare control and test coprocultures for dead L3 larvae numbers. A statistically significant difference between them indicates a larvicidal action from the bacteria studied (see Note 5).

4. Notes

1. Make notes of (1) the date of sample collection; (2) the time (mainly if the sample doesn't take chemical preserving because some helminthic eggs evolve quickly, which can make later identification difficult); (3) the animal species; (4) identification of the animal (for individual samples) or number of animals (for a flock); (5) sample consistency; (6) presence of mature parasites or blood, or any other fact that you consider important to remember.

2. This procedure allows separation of cysts, eggs, and other parasitic structures by employing a liquid of a higher specific weight that those of the parasites. Then parasites are recovered from the surface, and organic matter remains at the bottom of the recipient.

3. NaCl-saturated solution is the most utilized, but others hypersatured solutions such as magnesium sulphate (density 1.3 g/L), or zinc sulfate (density 1.2-1.25 g/L) can be used.

4. The fecal samples collected for coprocultures do not contain preserving solutions. The use of preserving solutions is only for to obtaining from fecal eggs different larval nematodes that are so similar they cannot be identified. On the other hand, observation of larvae obtained, allows systematic classification of different nematode parasites.

5. All laboratory material must be washed with water and hypochlorite sodium after use.

6. If it is not possible to identify all the larvae the same day, the assay tube can be maintained under refrigeration (12-14°C) for up to 4 mo.

References

1. Le Jambre, L. F. and Royal, W. M. (1976) A comparison of worm burdens in grazing Merino sheep and Angora goats. Aust. Vet. J. 52, 181-183.

2. Pomroy, W. E., Lambert, M. G., and Betteridge, K. (1986) Comparison of faecal strongylate egg counts of goats and sheep on the same pasture. N.Z. Vet. J. 37, 23-26.

3. Jallow, O. A., McGregor, B. A., Anderson, N., and Holmes, J. H. G. (1994) Intake of trichostrongylid larvae by goats and sheep grazing together. Aust. Vet. J. 71, 361-364.

4. Hoste, H. and Chartier, C. (1998) Response to challenge infection with Haemonchus contortus and Trichostronylus colubriformis in dairy goats. Consequences on milk production. Vet. Parasitol. 74, 43-54.

5. Romero, J. R. (2000) Selection of sheep with lower necessity of anthelmintic treatment. III Congreso Argentino de Parasitología, November, 2000, Mar del Plata, Argentina.

6 Eddi, C., Caracostantologo, J., Peña, M., et al. (1996) The prevalence of anthelmintic resistance in nematode parasites in sheep in southern Latin America: Argentina. Vet. Parasitol. 62, 189-197.

7. Fiel, C. A., Saumell, C. A., Steffan, P. E., Rodríguez, E. M., and Salaberry, G. (2000) Resistencia de los nematodes trichostrongylideos—Cooperia y Trichostrongylus—a tratamientos con avermectinas en bovinos de la Pampa Húmeda, Argentina. Rev. Med. Vet. 81, 310-315.

8. Saumell, C. A. (2000) No chemical methods for the control of helminths in veterinary practice. III Congreso Argentino de Parasitología, November, 2000, Mar del Plata, Argentina.

9 Bone, L. W., Bottjer, K. P., and Gill, S. S. (1985) Trichostronylus colubriformis: egg lethality due to Bacillus thuringiensis crystal toxin. Exp. Parasitol. 60, 314-322.

10 Bottjer, K. P., Bone, L. W., and Gill, S. S. (1985) Nematoda: susceptibility of the egg to Bacillus thuringiensis toxins. Exp. Parasitol. 60, 239-244.

11. Raibaud, P., Caulet, M., Galpin, J. V., and Mocquot, G. (1961) Studies on the bacterial flora of the alimentary tract of pigs. II. Streptococci: selective enumeration and differentiation of the dominant group. J. Appl. Bacteriol. 24, 285-291.

12. Willis, H. H. (1921) A simple levitation method for the detection of hookworm ova. Med. J. Aust. 8, 375.

13. Raynaud, J. P. (1970) Etude de l'efficacité d'une technique de coproscopie quantitative pour le diagnostic de routine et le controle des infestations parasitaires des bovins, ovins, equins et porcins. Ann. Parasitol. Hum. Comp. 45, 321-342.

Was this article helpful?

0 0

Post a comment