Parasitology

Research Article

Antagonistic activity of the fungus Pochonia chlamydosporia on mature and immature Toxocara canis eggs

A. S. MACIELa1 c1, L. G. FREITASa1, L. D. FIGUEIREDOa1, A. K. CAMPOSa2 and I. N. K. MELLOa3

a1 Laboratório de Controle Biológico de Nematóides, Instituto de Biotecnologia Aplicada à Agropecuária, Universidade Federal de Viçosa, Minas Gerais, 36570-000, Brazil

a2 Instituto de Ciências da Saúde, Universidade Federal do Mato Grosso, Mato Grosso, 78550-000, Brazil

a3 Laboratório de Parasitologia, Departamento de Veterinária, Universidade Federal de Viçosa, Minas Gerais, 36570-000, Brazil

SUMMARY

In vitro tests were performed to evaluate the ability of 6 isolates of the nematophagous fungus Pochonia chlamydosporia to infect immature and mature Toxocara canis eggs on cellulose dialysis membrane. There was a direct relationship between the number of eggs colonized and the increase in the days of interaction, as well as between the number of eggs colonized and the increase in the concentration of chlamydospores (P<0·05). Immature eggs were more susceptible to infection than mature eggs. The isolate Pc-04 was the most efficient egg parasite until the 7th day, and showed no difference in capacity to infect mature and immature eggs in comparison to Pc-07 at 14 and 21 days of interaction, respectively. Isolate Pc-04 was the most infective on the two evolutionary phases of the eggs at most concentrations, but its ability to infect immature eggs did not differ from that presented by the isolates Pc-07 and Pc-10 at the inoculum level of 5000 chlamydospores. Colonization of infective larvae inside or outside the egg was observed in treatments with the isolates Pc-03, Pc-04, Pc-07 and Pc-10. The isolate Pc-04 of P. chlamydosporia has great biological capacity to destroy immature and mature T. canis eggs in laboratory conditions.

(Received October 05 2011)

(Revised January 08 2012)

(Revised February 13 2012)

(Accepted February 14 2012)

(Online publication March 23 2012)

Correspondence:

c1 Corresponding author: Laboratório de Controle Biológico de Nematóides, Bioagro, Universidade Federal de Viçosa, Minas Gerais, 36570-000, Brazil. Tel: +55 31 38992925. E-mail: ale_spalenza@yahoo.com.br

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