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Biomedical subjects

J Pohlenz

Publications and source records attributed to J Pohlenz.

At least 91 records · Page 5Linked to original sources

Role of nutrition in the pathogenesis of porcine Escherichia coli enterotoxaemia.

The role of nutrition in the pathogenesis of E. coli enterotoxaemia was studied in weaned pigs inoculated with a field strain of E. coli O139:K82(B):H 4. Feeds extremely low in nutrients (5% crude protein, 4.6 MJ/kg digestible energy, 17% crude fibre) completely prevented the disease by inhibiting proliferation of the pathogenic bacteria in the intestine. This protective effect of the diet could not be used for disease control, because the pigs did not develop immunity. A diet moderately low in nutrients (8% crude protein, 9 MJ/kg digestible energy, 11% crude fibre) allowed proliferation of the inoculated bacteria to the point, where most of the pigs developed solid immunity and losses were significantly reduced. This diet combined with inoculation of the pigs with herd specific organisms allowed control of the disease in the field.

Animal Feed↗

Pathogenic relationships of rotavirus, Escherichia coli, and other agents in mixed infections in calves.

Infection with agents interpreted as causing or contributing to diarrhea (rotavirus, coronavirus, enterotoxigenic Escherichia coli, and cryptosporidia) were demonstrated in 24 of 32 newborn calves that had naturally occurring diarrheal disease. The calves were from 12 herds in Iowa. Infections as well as enteric lesions and hypoglobulinemia occurred more frequently among diarrheal calves than among nondiarrheal calves from these same herds. In most calves, infections were mixed; ie, both viruses, one or both viruses plus cryptosporidia, or rotavirus plus enterotoxigenic E coli.

Animals↗

Bovine cryptosporidiosis: a transmission and scanning electron microscopic study of some stages in the life cycle and of the host-parasite relationship.

Transmission and scanning electron microscopy of the ileal mucosae from 12 calves infected with Cryptosporidium sp. showed cryptosporidia free in the lumen and attached to epithelium. The attached parasites were interpreted to be extracellular and adherent to the microvillous border of epithelial cells. Stages of the organism included crescentic-free merozoites, trophozoites, schizonts, gametes and oocysts. Attached parasites were detected chiefly at villous tips and all stages were present on a single villus. Attachment sites were characterized by absence or disintegration of microvilli, disorganization of the terminal web and development of a specialized attachment zone. There were increased numbers of lysosomes and irregularities in the nuclear membrane of parasitized epithelial cells. It was concluded that cryptosporidia exist in bovine intestine as extracellular parasites and cause epithelial changes that in turn probably cause or contribute to diarrheal disease.

Animals↗

[On the effect of mebendazole on metacestodes of Mesocestoides corti and Echinococcus multilocularis (author's transl)].

Mebendazole (5-benzoyl-2-methoxycarbonylaminobenzimidazole) was highly effective against tetrathydridia of Mesocestoides corti in the peritoneal cavity, liver and in the subcutis of mice when administered orally in the food (450 or 465 ppm) from days 7 or 40/50 post infectionem (p.i.) for 10 or 20 days in total doses of approximately 660-1660 mg/kg body weight (b.w.). All tetrathyridia were killed when treatment began at day 7 p.i., and only some survived when medication was started on days 40/50 p.i. A treatment of 5 days was only partially effective. In experiments with Echinococcus multilocularis laboratory animals were intraperitoneally infected with metacestode tissue transplants. Beginning on days 4-7 p.i. or on day 40 p.i. the animals were treated for 5, 10 or 20/21 days with mebendazole medicated food. In mice a treatment for 10 or 20/21 days with total mebendazole doses of approximately 660-2180 mg/kg b.w. caused an average reduction on metacestode weight of 61-89%. An average reduction between 58 and 84% was achieved in Meriones after a treatment for 20/21 days with total doses of approximately 650/530 mg/kg b.w. However, histological examinations and transplantation experiments revealed that in most of the treated animals metacestode tissue survived and retained its capability for budding. On the other hand, indications for a partial destruction of the parasite tissue were found in some of the treated animals. The oral mebendazole treatment was well tolerated. After intraperitoneal injection of 3 X 150 mg/kg b.w. mebendazole - as applied by Campbell et al. (1975) - all of 36 mice or Meriones died.

Animals↗