Permanent Light Microscopy Slides of \u3ci\u3eEimeria nieschulzi\u3c/i\u3e Oocysts

The methods described here allow for the preparation of light microscopy slides of coccidian oocysts and thus, provide a durable sample and record for research and teaching. These methods used only one species, Eimeria nieschulzi; however, it is likely that use of other coccidian oocysts would produce similar results

On the Status of \u3ci\u3eEimeria nieschulzi\u3c/i\u3e Oocysts Embedded in Resin Eleven Years Ago: A Permanent Method for Preserving Coccidian Oocysts

Sporulated oocysts of Eimeria nieschulzi that were fixed and mounted on glass slides in polymerized resin in 1976 are examined. Size, shape, and integrity of oocysts and sporocysts are compared to similar observations we made in 1977 and reported in 1978 (Journal of Parasitology 64: 163-164). Our conclusion is that the methods we reported on in 1978 provide one opportunity to produce permanent specimens of sporulated oocysts that could be made available for deposit in nationally accredited museums

Prevalence of Antibodies to \u3ci\u3eToxoplasma gondii\u3c/i\u3e in Wild and Domestic Animals of New Mexico, Arizona and Colorado

Using the Sabin-Feldman dye test, sera from wild and domestic animals in New Mexico, Arizona and Colorado were tested for the prevalence of antibodies to Toxoplasma gondii. The prevalence of positive titers (≥ 1:8) in animals from these areas was: New Mexico (178 of 569, 31%), Arizona (11 of 56, 20%), and Colorado (2 of 7, 29%). The overall prevalence of antibodies to Toxoplasma was 30% (191 of 632). Nine of 17 fecal samples from wild zoo felines contained Toxoplasma-like oocysts which were inoculated per os and intraperitoneally into mice. Mice from six of these nine inoculations later showed positive dye test titers and tissues from five of these six groups had tissue cysts when examined histologically

Scanning and Transmission Electron Microscopy of the Oocyst Wall of \u3ci\u3eIsospora lacazei\u3c/i\u3e

The oocyst wall of Isospora lacazei from sparrows was studied with scanning (SEM) and transmission (TEM) electron microscopy. In TEM, t he oocyst wall consisted of four distinct layers (Ll-4). The innermost layer, Ll, was moderately electron-lucent and 240-285 nm thick; L2 was electronJense and 210-240 nm thick; L3 was moderately electron-lucent and 15-150 nm thick; L4, the outer most layer, was discontinuous and consisted of electron-dense discoid bodies which measured 180-220 nm x 320-840 nm. The discoid bodies of L4 as seen by TEM appeared spheroid in shape when observed by SEM. One or two membranes were situated on or between various layers of the oocyst wall. One such membrane occurred on the inner margin of Ll, two closely applied membranes were interposed between LI and L2, one membrane occurred between L2 and L3, and one membrane on the outer margin of L3

Ultrastructure of the Sporocyst Wall during Excystation of \u3ci\u3eIsospora endocallimici\u3c/i\u3e

Sporocysts of Isospora endocallimici, a parasite of marmosets, were exposed to minimal essentials medium (MEM) or a trypsin-bile salt solution (TBS) and then fixed and prepared for trans- mission electron microscopy. Excystation occurred in TBS but not MEM. The sporocyst wall has 2 layers, a thin outer layer (15 to 110 nm thick) and a thick inner layer (65 to 180 nm thick), which is composed of 4 separate curved plates. The outer layer consists of 1 to 3 membranes interspersed with lipid droplets. In the inner layer, a thin layer of material connects the peripheral margins of 2 apposing plates. Immediately beneath this layer, a thin strip of material is interposed between the 2 apposing plates. Ultrastructural changes preparatory to excystation occur primarily in the inner layer of the sporocyst wall. The TBS acts upon the site of apposition between 2 plates causing the interposed strip to swell and separate from the margin of each plate which leads to collapse of the sporocyst. As the sporocyst collapses, the margins of each curved plate curl inward toward the center of the sporocyst

Ultrastructure of \u3ci\u3eSarcocystis\u3c/i\u3e Sporocysts from Passerine Birds and Opossums: Comments on Classification of the Genus \u3ci\u3eIsospora\u3c/i\u3e

Sporocysts were obtained from the feces of opossums (Didelphis virginiana) which had been fed muscles of passerine birds (Molothrus ater and Cassidix mexicanus) infected with Sarcocystis. Sporocysts were examined by phase microscopy and scanning and transmission electron microscopy. Ridges on the surface of the sporocysts outlined four plates. Thin sections of the sporocyst wall showed thickened regions and gaps interpreted as cross sections of the ridges. The sporocyst wall has four major layers with a thick, granular inner layer which resembles the inner layer of sporocysts of related species. Excystation structures are discussed as a basis for classifying disporocystic coccidia to correlate with Frenkel\u27s (1977) life cycle classification of this group

Parasites of the Bobcat (Lynx rufus pallescens) in Central and Southern Utah

ABSTRACT: Carcasses of 28 bobcats, Lynx rufus pallescens Merriam, 1899 (10 adult and 2 juvenile males, 11 adult and 5 juvenile females) were surveyed for helminths. In addition, six live-trapped bobcats were examined for helminths and sporozoa. Thirty-three (97.1%) of the 34 bobcats harbored one or more species of parasite. No parasites were found in one of the bobcat carcasses. Parasite species identified and their prevalence from 28 bobcat carcasses included Taenia macrocystis (Diesing, 1850) During a study of home ranges and movements of bobcats (Lynx rufus pallescens Merriam, 1899) in central and southern Utah Materials and Methods Twenty-eight bobcat carcasses were collected from trappers in four central Utah counties (Juab, Millard, Sanpete, and Utah) and one southern county (Iron) during November and December 1979. In addition, six live bobcats were trapped in Diamond Fork Canyon, Utah County. Each carcass was grossly examined to determine the sex, and the lower canines from each animal were removed for age determination. Canines from bobcats less than one year of age retain an open apical foramen. Canine teeth with a closed foramen were sectioned, stained, and examined for cementum annuli The small and large intestines were removed from the carcasses, most of which had been frozen in the field. A sample of the contents of the large intestine was removed to determine diet selection. These samples were air-dried at 22°C for at least 30 days, crumbled, and examined under a dissecting microscope. Identification of intestinal contents was accomplished by examination of hair, bones, feathers, and vegetation aided by reference collections and identification keys The small and large intestines of each animal were fixed in 10% formalin and later examined in the laboratory for helminths. Cestodes were fixed in formolalcohol (70%) for 24 hr and placed in 70% ethyl alcohol (EtOH) until they could be stained in Semichon's acetic carmine. After staining, each specimen was dehydrated to 100% EtOH, cleared in methyl salicylate or xylene, and mounted in Permount®. In order to obtain flat hooks for measurements, each rostellum of all Taenia specimens was mounted separately en face. Nematodes recovered from the intestines were fixed in 70% EtOH, stored in glycerine-alcohol, and mounted in lactophenol. A sample of the diaphragm from each of the bobcat carcasses was examined microscopically for the presence of Trichinella larvae. Fecal and serum samples from the six live-trapped bobcats were also examined. Each fecal sample was placed in 3% potassium dichromate and later examined for helminth eggs and coccidia using a standard sugar flotation method. Serum samples were tested for antibodies to Toxoplasma gondii by the indirect hemagglutination method

Metabolomic profiling of permethrin-treated Drosophila melanogaster identifies a role for tryptophan catabolism in insecticide survival

Insecticides and associated synergists are rapidly losing efficacy in target insect pest populations making the discovery of alternatives a priority. To discover novel targets for permethrin synergists, metabolomics was performed on permethrin-treated Drosophila melanogaster. Changes were observed in several metabolic pathways including those for amino acids, glycogen, glycolysis, energy, nitrogen, NAD+, purine, pyrimidine, lipids and carnitine. Markers for acidosis, ammonia stress, oxidative stress and detoxification responses were also observed. Many of these changes had not been previously characterized after permethrin exposure. From the altered pathways, tryptophan catabolism was selected for further investigation. The knockdown of some tryptophan catabolism genes (vermilion, cinnabar and CG6950) in the whole fly and in specific tissues including fat body, midgut and Malpighian tubules using targeted RNAi resulted in altered survival phenotypes against acute topical permethrin exposure. The knockdown of vermilion, cinnabar and CG6950 in the whole fly also altered survival phenotypes against chronic oral permethrin, fenvalerate, DDT, chlorpyriphos and hydramethylnon exposure. Thus tryptophan catabolism has a previously uncharacterized role in defence against insecticides, and shows that metabolomics is a powerful tool for target identification in pesticide research