In vitro action of normal and immune sera on the larval and adult stages of Ancylostoma caninum
Banerjee, D.; Prakash, O.
Indian Journal of Medical Research 60(8): 1111-1119
1972
ISSN/ISBN: 0019-5340 PMID: 4676816 Document Number: 51829
The survival and development of Ancylostoma caninum infective larvae and adult worms was studied in vitro in sera from infected and uninfected dogs. Larvae survived longer in the normal sera (54 days) than in the immune sera (9 days); larvae failing to exsheath died more rapidly. 50% dilution of the sera with Krebs-Ringer bicarbonate solution increased survival of larvae in immune sera (more than 31 days) but did not alter survival in normal sera. Addition of merthiolate at 0.01% to the medium improved survival in all the above experiments. Circumoral and sometimes excretory pore precipitates developed around larvae in immune sera, but not in normal sera; no significant development beyond the 3rd stage was observed in any case. In general, adult worms survived longer in normal sera preparations than in those of immune sera in similar experiments, although the results are somewhat varied; in no case was any precipitation observed. 2 rhabditiform larvae were recovered from a normal serum preparation, as well as 35 to 40 from the uterus of a dead adult worm, indicating egg-laying activity. It is concluded that the precipitations observed in the immune sera indicate the presence of a precipitin type antibody, stimulated by the excretory and secretory products of invasive and migratory larvae and subsequently active against infective larvae, but not adult worms.