Cultivation of Free-Living Stages of Trichostrongylus colubriformis in Media without Bacteria, Animal Tissue Extract, or Serum

1985 ◽  
Vol 71 (2) ◽  
pp. 200 ◽  
Author(s):  
Willem Dorsman ◽  
Arend C. Bijl
2012 ◽  
Vol 21 (4) ◽  
pp. 372-378 ◽  
Author(s):  
Raquel Abdallah da Rocha ◽  
Patrizia Ana Bricarello ◽  
Gilberto Pedroso da Rocha ◽  
Alessandro Francisco Talamini do Amarante

This experiment aimed to assess the recovery of infective larvae (L3) of Trichostrongylus colubriformis from Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross and Panicum maximum cv. Aruana. The experimental module comprised six plots, with two plots per herbage species. Larval survival was assessed from autumn to winter, under the effect of two herbage-paring heights (5 and 30 cm). TThe paring was carried out immediately before contamination with faces containing T. colubriformis eggs. The feces and herbage were collected at one, two, four, eight, 12 and 16 weeks after feces had been deposited in the experimental plots. In general, larvae were recovered from both herbage and feces until the 16th week. The longer persistence of these larvae in the environment was probably due to warmer temperatures. The number of L3 recovered from the pasture was not influenced by the height of plants, except for Brachiaria and Aruana herbage in the fourth week. Regarding the concentrations of larvae per kg of dry matter (L3/kg DM), recovery was higher from low pasture in all three herbage species. During the autumn, the development and survival of the T. colubriformis free-living stages were not affected by the different herbage species.


1978 ◽  
Vol 64 (6) ◽  
pp. 1024 ◽  
Author(s):  
Z. I. Khan ◽  
W. Dorsman

1966 ◽  
Vol 52 (4) ◽  
pp. 713 ◽  
Author(s):  
Ferron L. Andersen ◽  
Guang-Tsan Wang ◽  
Norman D. Levine

Parasitology ◽  
1982 ◽  
Vol 84 (3) ◽  
pp. 455-462 ◽  
Author(s):  
D. A. Wharton

SummaryThe survival of the free-living stages of Trichostrongylus colubriformis under defined conditions of temperature and relative humidity was investigated. The survival of embryonated eggs was poor at 0, 33 and 54·5 % relative humidity (rel. hum.) at 20 °C but hatching occurred from a proportion of eggs even after exposure for 104 days to 76 and 98% rel. hum. at 20 °C. Second-stage larvae were desiccation-susceptible and were killed within 6 h even at 98% rel. hum. and 20 °C. Infective larvae, dried separately or in clumps, survived prolonged exposure to desiccation at 33–98% rel. hum. and 20 °C with 50% survival times of 58–164 days. Clump formation did not enhance survival in this range. Infective larvae also survived exposure to vacuum desiccation with 50% survival times of 8·8 h in clumps and 4·5 h when dried separately. The infective larva thus readily survives desiccation and may prove a useful model for the study of anhydrobiosis.


1989 ◽  
Vol 145 (1) ◽  
pp. 353-369
Author(s):  
D. A. Wharton ◽  
G. S. Allan

1. All free-living stages of the nematode parasite of sheep, Trichostrongylus colubriformis Giles, survived exposure to freezing temperatures in contact with water, with the exception of the first-stage juvenile (J1). The third-stage juvenile (J3) was the most resistant stage. The order of relative survival of the different stages was different from that of the lowest F50 (the temperature at which 50% froze), suggesting that an ability to supercool was not the only determinant of survival. 2. The F50 was shown to be a good measure of the degree of supercooling and to extend greatly the lower size limit of organisms that could be measured. 3. The J3 uses a freeze-avoiding strategy by supercooling when in air or covered by liquid paraffin. In water it uses a mixture of freeze-avoiding and freeze-tolerant strategies, with a proportion of the population surviving freezing caused by exogenous ice nucleation. 4. Removal of the J3 sheath results in a shift from freeze avoidance to freeze tolerance, with an overall reduction in survival. A major function of the sheath may be to reduce the probability of exogenous ice nucleation.


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