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Biomedical subjects

D J Forrester

Publications and source records attributed to D J Forrester.

At least 37 records · Page 2Linked to original sources

Hemoparasites of raccoons (Procyon lotor) in Florida.

Four hemoparasite species (Babesia lotori, Trypanosoma cruzi, Dirofilaria tenuis and Mansonella llewellyni) were found in raccoons (Procyon lotor) collected from 1972 to 1974 in Duval (n = 14) and Collier (n = 170) counties, Florida (USA). Trypanosoma cruzi was found in thin blood smears from one raccoon at each locality. The prevalence of B. lotori was 79% and 80% in samples taken in December 1973 in Collier and Duval counties, respectively. No patent infections by B. lotori were detected in raccoons collected in Collier County in December 1972, but 42% of the raccoons examined in September 1973 were infected. In Collier County there were no significant differences in the prevalence of B. lotori by host sex or age. In Duval County, overall D. tenuis prevalence was 7%, whereas that of M. llewellyni was 14%; the latter species was not found in Collier County. Adult raccoons had a significantly greater prevalence of D. tenuis (32%) than did subadults and juveniles (7%), and male raccoons showed a significantly greater prevalence (51%) than did females (8%).

Animals↗

Cysticerci (Cestoda: Taeniidae) from white-tailed deer, Odocoileus virginianus, in southern Florida.

Metacestodes (cysticerci) of Taenia omissa Lühe, 1910, and Taenia hydatigena Pallas, 1776, were found in 9 and 1 of 124 white-tailed deer, respectively, in southern Florida in 1984-1986. Intensities of T. omissa varied from 1 to 15 (mean = 4.6); only 1 cysticercus of T. hydatigena was collected. No significant difference in the prevalences of T. omissa according to sex, age, or locality was observed.

Age Factors↗

Intestinal coccidia of white-tailed deer in southern Florida.

From 1984 to 1986 110 white-tailed deer (Odocoileus virginianus) from Big Cypress National Preserve in southern Florida were examined for intestinal coccidial infections. Three species of Eimeria (E. mccordocki, E. madisonensis, and E. odocoilei) were found in low prevalences. There were no differences in prevalence due to age, sex, season of collection or specific locality within the Preserve.

Animals↗

Pathogenicity of Haemoproteus meleagridis (Haemosporina: Haemoproteidae) in experimentally infected domestic turkeys.

Sporozoite-induced experimental infections of Haemoproteus meleagridis produced a moderate to severe myositis and significant effects on weight gain and growth in domestic turkey poults. Pathological effects occurred in both low- and high-dose infections (4,400 and 57,500 sporozoites, respectively). Low-dose birds weighed significantly less than controls at 3 wk postinfection (PI) when peripheral parasitemia reached a peak and had significantly shorter tarsometatarsal lengths at both 1 and 3 wk PI. High-dose birds were significantly lighter and smaller than control and low-dose birds throughout the course of the 8-wk study. Infected birds were not anemic in spite of high parasitemias that often exceeded 50% of circulating erythrocytes. The most serious pathological effects occurred prior to patency and were associated with development of megaloschizonts in skeletal muscle. Microscopic lesions in 4 high-dose birds that died between 19 and 22 days PI were characteristic of a severe, acute hemorrhagic myositis. Megaloschizonts were surrounded by a hemorrhagic inflammatory infiltrate composed of macrophages, heterophils, giant cells, and red blood cells. Muscle fibers adjacent to megaloschizonts were swollen, hyaline, and contained prominent calcium deposits. Other observations included enlargement of the spleen, deposition of pigment in macrophages of the lung and spleen, and secondary bacterial and fungal infections in the intestine and lungs. Necrotic and calcified muscle fibers and degenerating megaloschizonts were still present at 8 wk PI when the experiment ended. Our results demonstrated significant pathological changes in H. meleagridis-infected domestic turkeys that were associated primarily with preerythrocytic stages of development.

Animals↗

Helminths of the Florida manatee, Trichechus manatus latirostris, with a discussion and summary of the parasites of sirenians.

We examined 215 Florida manatees (Trichechus manatus latirostris) at necropsy to determine the helminth fauna. Six species were identified: Heterocheilus tunicatus (Nematoda: Ascaridoidea); Anoplocephala sp. (Cestoda: Cyclophyllidea); and 4 species of trematodes, Cochleotrema cochleotrema (Digenea: Opisthotrematidae), Chiorchis fabaceus (Digenea: Paramphistomatidae), Nudacotyle undicola (Digenea: Nudacotylidae), and Moniligerum blairi (Digenea: Opisthotrematidae). Seventy-three percent of the manatees examined were infected with at least 1 species of helminth. The mean number of species of helminths per infected manatee was 1.9 with a range of 1-4. Fifty-nine manatees were helminth-free; 30 of these were calves. No associations were found between the intensity of helminth infections and host sex, age class, season, and geographic location of recovery, or cause of death. Differences in parasite prevalence between age classes were highly significant for Chiorchis, Cochleotrema, and Heterocheilus, due to a low number of infected calves. A higher prevalence of Cochleotrema was found in manatees recovered from eastern Florida, and Heterocheilus was evident in significantly more manatees from western and souther Florida. Comparisons in the parasite fauna are made among Florida manatees and other sirenian populations, and a brief review of sirenian parasites is included.

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Myopathy associated with megaloschizonts of Haemoproteus meleagridis in a wild turkey from Florida.

Necropsy of an emaciated adult wild turkey (Meleagris gallopavo osceola) that died in captivity soon after capture revealed numerous macroscopic 1-2 mm white cysts in the pectoral muscles. Microscopic, aseptate protozoan megaloschizonts, 50-150 microns in diameter, corresponded to the cysts in histological sections. The megaloschizonts were surrounded by a thick, hyaline wall and packed with spherical merozoites less than 1 micron in diameter. Muscle fibers surrounding most of the megaloschizonts exhibited early signs of dystrophic calcification. The fibers were swollen, pale and hyaline and contained scattered basophilic granules. The megaloschizonts were morphologically distinct from sarcocysts of Sarcocystis sp. and Besnoitia sp. and the thin-walled tissue cysts of Toxoplasma gondii. They were identical in structure and host reaction to the second-generation megaloschizonts of Haemoproteus meleagridis, reported previously from experimentally infected domestic turkeys. While the precise cause of death of the wild turkey could not be determined, the most prominent lesions were associated with the numerous intramuscular megaloschizonts.

Animals↗

Pre-erythrocytic development and associated host responses to Haemoproteus meleagridis (Haemosporina: Haemoproteidae) in experimentally infected domestic turkeys.

Two generations of pre-erythrocytic schizogony occurred in skeletal and cardiac muscle of domestic turkeys infected with sporozoites of Haemoproteus meleagridis. First generation schizonts reached maturity approximately five days post-inoculation (DPI) and developed in capillary endothelial cells and myofibroblasts. The schizonts ranged from 12 to 20 microns in diameter and produced long (5-6 microns), slender merozoites. Early second generation schizonts were first detected in capillary endothelial cells between 5 and 8 DPI. They were cylindrical and ranged in size from 5 to 8 microns in diameter and up to 28 microns in length. Second generation schizonts which reached maturity by 17 DPI were surrounded by a thick, hyaline wall and were packed with numerous spherical merozoites less than 1 micron in diameter. Mature megaloschizonts were fusiform, ranged from 30 to 113 microns in diameter, and extended as much as 465 microns along the long axis of muscle fibers. Merozoites developed as buds from cytomeres that formed between 8 and 14 DPI. Infected turkeys developed a moderate to severe myositis within 5 DPI and were lame in one or both legs. The myositis was associated with the necrosis of scattered groups of muscle fibers. Muscle fibers surrounding mature megaloschizonts were swollen and hyaline. Megaloschizonts were surrounded occasionally by fibroblasts and infiltrates of mononuclear cells. The morphology and site of development of mature megaloschizonts of Haemoproteus meleagridis are contrasted with those of other avian haemosporidians.

Animals↗

Residues of chlorinated hydrocarbons in tissues of raptors in Florida.

Dead or moribund raptors (n = 75) representing 11 species were collected between 1971 and 1981 from various locations in Florida. Samples of bran, muscle, liver and adipose tissue were analyzed for DDT, DDE, DDD, dieldrin, and PCB's. Detectable concentrations of DDT or its metabolites were found in 100% of all samples of muscle and liver, and 77% all samples of brain. Dieldrin was determined to be present in 91%, 93%, 87% and 78% of all samples of brain, muscle, liver and adipose tissue, respectively. Lethal or hazardous concentrations of dieldrin were found in brain samples from three birds, but DDT and PCB's were present at sublethal concentrations. When species were grouped according to their dietary habits, it was not possible to identify any trends in pesticide concentrations.

Adipose Tissue↗

Experimental transfer of Trichomonas gallinae (Rivolta, 1878) from white-winged doves to mourning doves.

Isolates of Trichomonas gallinae (Rivolta, 1878) from white-winged doves, Zenaida asiatica (L.), were transferred experimentally to young mourning doves, Zenaida macroura (L.). Twenty-three of 25 mourning doves developed infections with isolates of T. gallinae from 25 white-winged doves. In addition, eight of eight rock doves (Columba livia Gmelin) were infected with duplicate isolates. All infected recipient birds harbored avirulent isolates except for one mourning dove which died from extensive oral lesions. However, repeated attempts using this isolate of T. gallinae to produce lesions in additional recipients were unsuccessful. Despite the findings of this study, it was suggested that future dove management strategies consider the possibility of disease outbreaks involving white-winged doves and susceptible populations of mourning doves.

Animals↗

Lungworms of feral swine in Florida.

Metastrongylus apri, M salmi, and M pudendotectus were found in 94%, 76%, and 64%, respectively, of 90 feral swine from a study area in southern Florida. The mean number of worms per infected animal was 155, with a range of 1-1,980 (1 or more species). Metastrongylus apri was found singly or in combination with 1 or both of the other species. Single or concurrent infections of M salmi and M pudendotectus were not found. Male hogs had significantly (P less than 0.05) higher intensities of M apri infection. Juvenile animals were infected with M apri only, but subadults and adults were infected with all 3 species. Hogs examined during October, November, and December had significantly (P less than 0.05) higher intensities of infection of all 3 species, compared with hogs examined at other times of the year. There were significant (P less than 0.05) interactions between host sex, host age, and season for intensities of infection with M pudendotectus.

Animals↗

Experimental transmission by mosquitoes of Plasmodium hermani between domestic turkeys and pen-reared bobwhites.

Plasmodium hermani was experimentally transmitted from domestic turkey poults (Meleagris gallopavo) to pen-reared bobwhites (Colinus virginianus) and then from these bobwhites back to domestic turkey poults. Transmission was achieved by Culex nigripalpus both by bites of the mosquito and by intraperitoneal injection of sporozoites. All of the 23 bobwhites and the 13 turkeys exposed to sporozoites became infected. These results indicate that the bobwhite might be a reservoir host for this malaria of wild turkeys in nature.

Animals↗