A Comparative Study of Detergent Effects on Ascarid Development

Abstract

The resistance of ascarid eggs to varying conditions of temperature, humidity, and to various chemical agents is well known. Seamster (1950) and Jaskoski (1952) reviewed the pertinent literature and especially that concerning eggs of the swine ascarid. Ackert and Cauthen (1931) observed the effects of varied climatic conditions on the eggs of Ascaridia galli. Christenson et al. (1942) made a comparative study of the development of eggs of Ascaridia galli and Heterakis gallinae. They reported that eggs of A. galli were slightly less resistant to nicotine alkaloid than those of H. gallinae, but that Heterakis eggs had a lower thermal death point and appeared to be viable for longer periods of time. Hartman (1923) and Ackert and Cauthen (1931) observed that the eggs of Ascaridia from chickens were less resistant than the eggs of mammalian ascarids. Owen (1928), Taylor (1924), and Otto (1929) reported on the resistance of eggs of Toxacara canis and Toxacara cati under varied soil conditions and experimental laboratory conditions where temperature and humidity could be controlled. Eggs of the common cat and dog ascarids were reported to be generally more resistant to cold than to warm, dry temperatures. Lucker (1939) observed that certain haldgenated hydrocarbons were lethal to the eggs of T. canis. Chlorosol and ethylene dichloride were found effective ovicides in the soil, the latter compound being more effective than CC14 or dichloropentane. The nature of this resistance may best be sought by examination of the three egg membranes surrounding the ascarid ovum. Chitwood (1938) observed that the outer membrane is a protein, the middle membrane a chitinous supporting layer, and the inner a lipoid membrane. Ransom and Foster (1920), Zawadowsky (1928), and Hyman (1951) pointed out that the lipoid membrane is extremely important in regard to egg resistance* and is impervious to all materials except lipoid soluble ones. Since the chemical constituents of egg membranes of most ascarids are the same, it appeared timely to test the effects of chemical agents on the eggs of several of these species. The classification by Chitwood (1950), including Heterakis in the superfamily Ascaridoidea, is used here. In preliminary work the author (1950) noted that certain commercial detergents exhibited a faster ovicidal effect if the two outer coats of the swine ascarid egg had been dissolved by a hypochlorite solution (anti-formin) before subjection to the detergents. Acknowledgement.-The author gratefully acknowledges a generous supply of the detergents used from the Monsanto Chemical Company, the Union Carbide and Carbon Corporation, the Allied Chemical and Dye Corporation, and the E. I. DuPont de Nemours and Company. Appreciation is also expressed to Armour and Company, Omaha, for a supply of swine ascarids; to Dr. K. B. Kerr and Mr. W. C. McGuire of Dr. Salsbury's Laboratories for generous supply of chicken ascarids and heterakis used. Miss Jean Bonnema assisted in the experimental work.