Proc. Helminthol. Soc. Wash. 52(1), 1985, pp. 138-139

Research Note

Attempts to Stimulate Resistance to in Calves with mansoni Cercariae

ROBERT A. KNIGHT Parasitology Institute, Agriculture Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705

Sirag et al., demonstrated resistance to Fas- postinoculation with F. hepatica. Calves inocu- ciola hepatica in calves that harbored patent lated with S. mansoni cercariae were examined (1981, J. Helmin- at necropsy for schistosomes. Results were sub- thol. 55:63-70). Cross-reactive antigens have jected to analysis of variance for significance. been reported in F. hepatica and Schistosoma EXPERIMENTAL DESIGN: Experiment 1. Five mansoni (Hillyer, 1981, Bol. Asoc. Med. Puerto calves were assigned to groups of three and two Rico 73:150-161), and mice have been protected calves each. The three calves of Group 1 were from challenge infections with S. mansoni by inoculated with S. mansoni cercariae as follows: prior inoculation with various F. hepatica anti- one received 17,000 cercariae 6 wk before F. gens (Hillyer and Serrano, 1982, J. Inf. Dis. 145: hepatica challenge; one received 36,000 cercariae 728-732). Christensen et al. (1980, Exp. Paras- 3 wk before challenge; one received 17,000 and itol. 49:116-212) reported patent S. mansoni in- 36,000 cercariae 6 and 3 wk, respectively, before fections in mice resulted in resistance to F. he- challenge. Calves of Group 2 were not inoculated patica infections. Natural infections of cattle with with S. mansoni cercariae. Three weeks after the S. mansoni have been reported in Brazil (Bar- bosa et al., 1962, Science 138:831), and because cattle become resistant to reinfection with F. he- patica (Nansen, 1974, Nord. Vet. Med. 26:18- Table 1. Numbers of Fasciola hepatica recovered at 20; Kendall et al., 1978, J. Comp. Pathol. 88: necropsy from calves inoculated with Schistosoma 115-122), conceivably a protective resistance to mansoni cercariae compared with control calves. by F. hepatica through prior inocula- tion with S. mansoni could be developed. Re- No. % ported herein are results of tests attempted to Calves F. hepatica Inoculum produce such a protective resistance in calves Experiment 1 against F. hepatica by inoculations with S. man- S. mansoni calves 78 16 soni cercariae. 73 15 Two experiments were conducted using F. he- 86 17 patica-naive Holstein bull calves ranging in age Average 79 16 from 6 mo to 1 yr. They were fed a maintenance Control calves 100 22 ration of alfalfa hay and water ad lib. 155 31 The S. mansoni cercariae were freshly shed Average 133 27 when obtained from the Biomedical Research Experiment 2 Institute in Rockville, Maryland. Cercariae were S. mansoni calves 103 29 counted and calves were inoculated subcutane- 111 32 62 18 ously by syringe with cercariae suspended in dis- 48 14 tilled water. After the experimental regimen for 53 15 schistosome exposure, all calves within an ex- Average 75 21 periment were challenged with oral inoculation Control calves 44 13 of F. hepatica cysts on filter paper in gelatin cap- 54 15 sules. Necropsies of challenged calves were made 54 15 15 wk postinoculation of cysts. Fecal samples 43 12 were collected for egg counts (Knight, 1985, Proc. 42 12 Helminthol. Soc. Wash. 51:349-351) 13 weeks Average 42 12

Copyright © 2011, The Helminthological Society of Washington 139

last administration of cercariae all calves were longer period of time to provide greater antigenic challenged with 500 F. hepatica cysts. stimulation. At necropsy, however, no significant Experiment 2. Ten calves were assigned to two difference was found between experimental and groups of five calves each. The calves of Group control groups. 1 were each inoculated weekly with 12,500 S. None of the calves in either experiment de- mansoni cercariae for 6 wk, totaling 75,000 cer- veloped a patent S. mansoni infection; only eggs cariae per calf; calves of Group 2 were not in- of F. hepatica were found, and no schistosomes oculated with S. mansoni cercariae. Three weeks were recovered at necropsy. Christensen et al. after the last administration of cercariae all calves (1980, op. cit.) found that patent infections of were challenged with 350 F. hepatica cysts. both sexes of S. mansoni with resultant egg pro- The numbers of flukes at necropsy are pre- duction were necessary to produce resistance in sented in Table 1. In Experiment 1, the average mice to F. hepatica. Likewise, resistance report- number of F. hepatica recovered from control ed by Sirag et al. (1981, op. cit.) resulted from a calves was higher than the average number re- patent infection of 5*. bovis. In the tests reported covered from calves inoculated with S. mansoni, here, no resistance to F. hepatica was produced and though the difference was not statistically by exposure to S. mansoni cercariae, supporting significant it seemed to warrant further tests. In the concept that patent infections with S. man- Experiment 2, calves were inoculated with a soni are necessary to stimulate resistance to F. greater number of S. mansoni cercariae over a hepatica.

Proc. Helminthol. Soc. Wash. 52(1), 1985, pp. 139-140

Research Note Two Rare Helminths in an Osprey, Pandion haliaetus, in Mexico

GERALD D. SCHMIDT AND PAULINE M. HUBER Department of Biological Sciences, University of Northern Colorado, Greeley, Colorado 80639

In October 1981, an adult male osprey, Pan- Gruzinsk. SSR, 14:105-145). This, then, is its dion haliaetus, was found impaled on a television first record in North America. Voucher speci- antenna in the town of Puerto Penasco, Sonora, mens are deposited in USNM Helm. Coll. Mexico. This small village is located near the (USDA, Beltsville, Maryland) No. 77183. northern end of the Gulf of California, 98 mi Thirty-five Scaphanocephalus expansus south of Lukeville, Arizona. The still-living bird (Creplin, 1842) Jagerskiold, 1903 (: Het- was brought by a resident to the Center for the erophyidae) were recovered from the small in- Study of Deserts and Oceans, where it died the testine. This parasite has been reported from os- same night. Examination of the digestive tract preys in Europe, Asia, and Africa. There are three revealed two species of helminths, both so rare prior records of it in North America. Hoffman that their occurrence should be recorded. (1953, J. Parasitol. 39:568) found adult worms Eighteen adult Sexansocara skrjabini Sobolev in an osprey in Iowa (USNM Helm. Coll. No. et Sudarikov, 1939 (Nematoda: Acuriidae) were 46437). This is the only prior record of adults in found in the proventriculus. This species was first North America. Metacercariae were found en- discovered in Gorkii, Russia (Sobolev and Su- cysted in the , fins, gills, and eyes of marine darikov, 1939, Tr Gor'k. Gos. SeFskokhoz. Inst. fishes in Florida by Hutton (1964, Trans. Am. 39:97-103) in the same . It was also reported Microsc. Soc. 83:439-447), and by Skinner (1979, from the osprey from Georgian SSR (Kurashvili, Bull. Mar. Sci. [for 1978] 28:590-595). This is [1954], Rabot. Gel'mintol. 75-Let. Skrjabin, pp. the second record of adult S. expansus in the 340-346; 1956, Trudy Inst. Zool. Akad. Nauk Western Hemisphere and the first of the species

Copyright © 2011, The Helminthological Society of Washington