William L. Current

Human cryptosporidiosis in immunocompetent and immunodeficient persons. Studies of an outbreak and experimental transmission.

Infection with cryptosporidium occurred in 12 immunocompetent persons who had direct contact with the feces of infected calves during three unrelated outbreaks of calf cryptosporidiosis. Nine of the twelve subjects had diarrhea and abdominal cramps that lasted 1 to 10 days. Infections were diagnosed and monitored by detection of oocysts in feces, with a modified Sheathers flotation technique and phase-contrast microscopy. Oocysts of cryptosporidium were isolated from calves but not from other animals with which these subjects had been in contact. Oocysts of cryptosporidium were also detected during repeated examinations of feces from two immunodeficient patients with persistent cryptosporidiosis. An apparently identical infection was transmitted to calves and mice, using oocysts from infected calves and human beings. Oocysts from an immunodeficient person also produced infections in kittens, puppies, and goats. This study shows that cryptosporidium may produce a moderate self-limited illness in immunocompetent persons, which contrasts sharply with the prolonged severe diarrhea in immunocompromised patients who contract cryptosporidiosis. Calves with diarrhea should be considered a potential source of human infection, and immunocompromised persons should avoid contact with such animals.

The species of Cryptosporidium (Apicomplexa: Cryptosporidiidae) infecting mammals.

Oocysts of Cryptosporidium muris (Apicomplexa: Cryptosporidiidae) were obtained from the feces of naturally infected calves. Oocysts were fully sporulated in fresh feces, measured 7.4 X 5.6 (6.6 - 7.9 X 5.3 - 6.5) micron, and possessed a longitudinal suture along one pole of the oocyst wall. Morphologic and biologic evidence obtained from this study demonstrated that C. muris is a species distinct from Cryptosporidium parvum, which has smaller oocysts.

Cryptosporidium: Its biology and potential for environmental transmission

Protozoans of the genus Cryptosporidium are small (2 to 6 μm, depending on life cycle stage) coccidian parasites that reside within the microvillous region of the mucosal epithelium of man and a variety of animals. Infections with Cryptosporidium spp. were considered rare in animals, and in man they were thought to be the result of a little‐known opportunistic pathogen outside its normal host range. Our concept of Cryptosporidium has changed within the past 4 years to that of a significant and widespread cause of diarrheal illness in several animal species, especially calves and humans. In immunocompetent humans, this protozoan may produce a mild to severe diarrheal illness lasting from several days to more than 1 month. In immune‐deficient persons, especially those with the acquired immune deficiency syndrome (AIDS), cryptosporidiosis usually presents a prolonged, life‐threatening, cholera‐like illness. Treatment of cryptosporidiosis, especially in immune‐deficient persons, has been for the most part uns...

Infection dynamics of Cryptosporidium parvum (Apicomplexa: Cryptosporiidae) in neonatal mice (Mus musculus).

maintained alive in a dechlorinated city water supply. Based on their size and immaturity, the hosts collected in the 1982 survey likely had not spent any time at sea. Anadromous fishes, such as eulachon (Thaleichthys pacificus (Richardson)) or possibly salmonids, that had returned to fresh water to spawn after a period of marine life were probably the source of the marine parasites found in the sturgeon. Semakula and Larkin (1968, loc. cit.) noted that eulachon form an important part of the diet of Fraser River white sturgeon. As mentioned above, Becker (1970, loc. cit.) offered a similar explanation for the occurrence of T. lindbergi in Columbia River white sturgeon. For reasons unexplainable at present, Corynosoma strumosum was found only in female sturgeon (9/21 examined), the difference in prevalence of infection between the sexes being statistically significant (Fishers exact probability test, P = 0.0083). There were no statistically significant host sex differences in prevalence of the other parasite species encountered. The present report represents the first on parasites of the Fraser River stock of white sturgeon, which is one of the major stocks of this North American sturgeon species. Voucher specimens of the parasites reported herein have been deposited in the National Museum of Natural Sciences, Invertebrate Collection (Parasites), Ottawa, Canada, and bear the following numbers: Crepidostomum auriculatum, NMIC(P) 1985-0115; Diphyllobothrium sp., NMIC(P) 1985-0116; Amphilina bipunctata, NMIC(P) 1985-0117; Corynosoma strumosum, NMIC(P) 1985-0118; Cystoopsis acipenseris, NMIC(P) 1985-0119; Anisakis simplex, NMIC(P) 1985-0120; undetermined nematode larvae, NMIC(P) 1985-0121. In addition, 4 specimens of C. auriculatum have been deposited in the Harold W. Manter Laboratory, University of Nebraska State Museum, Lincoln, Nebraska (No. 22983), and specimens of all species, except Diphyllobothrium sp. and A. bipunctata, are retained in the collection of the Pacific Biological Station. Specimens of A. bipunctata were given to Dr. G. Malmberg, University of Stockholm. We are pleased to acknowledge the assistance of Dr. Mary Hanson Pritchard and Dr. Janine Caira (Harold W. Manter Laboratory, University of Nebraska) in verifying the identification of C. auriculatum.

Ultrastructure of Interlamellar Henneguya exilis in the Channel Catfish

Ultrastructural aspects of interlamellar Henneguya exilis infections in channel catfish are reported. The plasmodium wall of this form differs from that of other species in that it is composed of two outer unit membranes which give rise to a zone of numerous pinocytic canals. Single-membraned canals appeared to be a stable feature of the wall while double-membraned canals are interpreted as those actively carrying out pinocytosis. Evidence suggests that host cellular cytoplasm as well as interstitial material is taken in by plasmodia. Plasmodium wall integrity, aggregation of parasite ectoplasmic components, numbers of pinocytic canals, and number of mitochondria proximal to the wall vary among different plasmodium profiles and may be related to plasmodium maturity. The parasite causes extensive hyperplasia of basal cells, which in turn replaces most other cell types found in noninfected gill filaments. Cytoarchitectural differences between basal cells of noninfected filaments and basal cells adjacent to plasmodia include significantly shorter microfilament bundles in the latter.

SPOROGONY OF ISOSPORA SUIS BIESTER, 1934 OF SWINE

Sporogony of Isospora suis of swine is described. Unsporulated oocysts were collected immediately after defecation, mixed in 2.5% potassium dichromate solution, incubated at various temperatures, examined at different time intervals, and classified as to stage of development. The uninucleate sporont underwent nuclear division and became binucleated, and then divided to form two round, uninucleate sporoblasts. Binucleate sporoblasts elongated to form binucleate sporocysts, each of which then gave rise to four sporozoites. Sporulation was completed within 56 hr at 20 C, 40 hr at 25 C, 16 hr at 30 C, and 12 hr at 37 C. No sporulation occurred at 4, 40, 42, 45, or 50 C. The thermal death point was between 37 and 40 C.

A review of the genus Caryospora Léger, 1904 (Apicomplexa: Eimeriidae)

SummaryThe genus Caryospora (Apicomplexa, Eimeriorina) contains 30 species of coccidia that develop primarily in reptiles and predatory birds. Recent studies have shown that some species of Caryospora are heteroxenous, with both asexual and sexual phases of parasite development occurring in the intestinal epithelium of a predatory reptile or bird and in dermal connective tissues of rodents. The life-cycle of these Caryospora spp. is distinct from all known genera of the Eimeriidae. In this paper we present a review of and redefine the genus Caryospora, present succinct taxonomic descriptions, synonyms and lapsi, and provide line drawings (if available) of oocysts of each of the described species. ac]19841022

Two new species of Isospora (Apicomplexa: Eimeriidae) from passeriform birds of South America

SummaryTwo new species of Isospora (Apicomplexa: Eimeriidae) are described from the faeces of passeriform birds of South America. I. cyanocoracis n. sp. is described from Cyanocorax chrysops (Passeriformes: Corvidae) and I. paroariae n. sp. from Paroaria coronata (Passeriformes: Emberizidae). I. cyanocoracis oocysts are spherical or subspherical, 28.7×26.8 μm (25.0–30.5×24.5–29.0), with bi-layered wall about 2.0 μm thick. Micropyle and oocyst residuum are absent; large polar granule present. Sporocysts are ovoid, 19.3×11.4 μm (17.0–21.0×10.5–12.2), with smooth, single-layered wall about 0.8 μm thick. Stieda and substiedal bodies and sporocyst residuum are present. Sporozoites 12.2×4.2 μm (10.5–15.0×3.5–4.5), possess spherical anterior and posterior refractile bodies. I. paroariae oocysts are spherical or subspherical, 22.3×21.4 μm (19.5–25.5×18.5–24.0), and have bi-layered wall about 1.8 μm thick. Micropyle, polar granule, and oocyst residuum are absent. Sporocysts ovoid, 15.2×10.0 μm (14.0–16.5×8.0–11.5), possess smooth, single-layered wall about 0.7 μm thick. Stieda and substiedal bodies and sporocyst residuum are present. Sporozoites elongate, 11.3×3.4 μm (10.0–13.5×3.2–4.0), have single, large, posterior refractile body. ac]19840712

Syntheses and antifungal activities of novel 3-amido bearing pseudomycin analogues.

As a result of our core SAR effort, we discovered a large number of 3-amido pseudomycin B (PSB) analogues (e.g., 4e LY448212 and 5b LY448731) that retain good in vitro and in vivo (IP) activities against Candida and Cryptococcus without inherent tail vein irritation. Several dimethylamino termini bearing 3-amides (e.g., 5b) also exhibited improved potency against Aspergillus in vitro. When evaluated in a two-week rat toxicology study, it was found that all animals receiving 4e (up to 75 mg/kg) were found to be normal. On the basis of these observations, we are convinced that it is possible to broaden the antifungal spectrum and improve the safety profile of pseudomycin analogues at the same time.

Mouse-to-mouse transmission of Caryospora simplex (Apicomplexa: Eimeriidae).

Caryospora simplex Leger, 1904 (Apicomplexa: Eimeriidae) is a heteroxenous coccidium that infects the intestinal epithelium of viperid snakes (Leger, 1911, Archiv fur Protistenkunde 22: 71-88) and, experimentally, dermis of rodents (Upton et al., 1984, Journal of Protozoology 31: 392-398). When mice ingest sporulated oocysts of C. simplex of snake origin merogony, gamogony, and sporogony occur in fibroblastlike cells of the facial and tongue dermis. Unlike snake-derived oocysts, however, oocysts developing in the dermis of mice possess a much thinner wall and lack a distinct sporocyst wall, Stieda, or substieda bodies (Upton et al., 1984, loc. cit.). Sporozoites appear to exit from these thin-walled oocysts on days 12-14 post-inoculation (PI), enter macrophage-like cells within the dermis and remain dormant as a cystic stage that is presumed to be infective for the snake host. These monozoic cysts of Caryospora spp. have been termed caryocysts (Wacha and Christiansen, 1982, Journal of Protozoology 29: 272-278). The present study was undertaken to determine if caryocysts of C. simplex are infective to mice and to determine if cannibalism may play a role in the transmission and maintenance of the parasite within the rodent population. Three separate groups of 4-6 wk old, female, coccidiafree Swiss-Webster mice were used for the experiment. All mice were housed in groups of 2 in metal bottom cages, with experimentally infected animals maintained separately from controls. Bedding consisted of wood shavings and was changed at 48 hr intervals. All animals were given commercial rodent chow and water ad lib. Group A consisted of 8 mice inoculated by stomach tube with 250,000 sporulated oocysts obtained from the feces of an Ottoman viper, Vipera x. xanthina (see Upton et al., 1984, loc. cit.) and 2 uninoculated controls. Two inoculated mice were killed by cervical dislocation on days 10, 15, 18, and 25 PI and portions of the cheek dermis were examined for developmental stages of C. simplex by Nomarski interference contrast (NIC) microscopy. Examination of tissues at these intervals insured that parasite stages were developing at the same intervals as reported previously (see Upton et al., 1984, loc. cit.). Control mice killed on day 25 PI were examined similarly. Portions of cheek dermis from each of the 2 inoculated mice killed on day 25 PI were minced and equal portions were fed separately to each of 2 coccidia-free mice (Group B). Two additional coccidia-free mice in Group B received similar portions of cheek dermis from the 2 uninoculated control mice in Group A. All mice in group B were killed on day 25 post-feeding and examined for the presence of parasites as described above. Equal portions of cheek dermis from infected mice in Group B were then fed separately to 2 coccidia-free mice (Group C). Two additional mice in Group C were fed similar portions of cheek dermis from the 2 control mice in Group B. All 4 mice in Group C were examined for the presence of parasites 25 days after being fed infected or uninfected cheek tissues, as described above. Mice in Group A inoculated with oocysts from the snake had developmental stages of C. simplex on days 10, 15, 18, and 25 PI similar to those reported by Upton et al. (1984, loc. cit.). Caryocysts on day 25 PI (Fig. 1) appeared viable. No parasite stages were found in the 2 control mice of Group A. Both mice in Group B inoculated with infected cheek dermis from mice in Group A and necropsied on day 25 PI had numerous caryocysts within the cheek dermis and, although quantitative comparisons were not made, caryocysts appeared more numerous than in mice of Group A. Control mice in Group B fed cheek dermis from control mice in Group A were not infected. Mice in Group C receiving