Observations on the epidemiology and interactions between myxomatosis, coccidiosis and helminth parasites in a wild rabbit population in Scotland

A study of the epidemiology of myxomatosis and the protozoan liver parasite, Eimeria stiedae, in a population of wild rabbits in Scotland from 1977 to 2010 is reported. Rabbits were collected on a monthly basis resulting in a total of 5,337 animals examined for the infections. The investigation showed that within any 1 year over the 34 years of the investigation the percentage of rabbits with myxomatosis varied between 0 and 24 %, while for E. stiedae infections fluctuated between 3 and 42 %. There were strong seasonal trends in the prevalence of myxomatosis with over 16 % being infected in September and October, and for E. stiedae, peaks of over 40 % of livers infected were recorded in July. From 2007 to 2010, faeces were also examined for coccidia oocysts and parasitic nematode eggs. Rabbits infected with the myxoma virus had mean oocyst counts of 73,665 per gram faeces, while rabbits not infected with the myxoma virus had counts of 31,952 oocysts per gram. Comparable figures for nematode faecal egg counts were 911 per gram in myxomatosis-infected animals and 427 per gram in uninfected animals. The elevated nematode faecal egg counts in rabbits with myxomatosis reflects increased worm burdens already reported, but the elevated counts of coccidial oocysts have not previously been reported. This would suggest that myxomatosis could compromise rabbit immunity to nematodes and coccidia.     

Enzyme levels in homogenates of liver from mice infected with Schistosoma mansoni and from uninfected mice

Enzymatic and histopathological study of the livers of 300 white mice infected with Egyptian strain of Schistosoma mansoni and of 100 noninfected control animals was carried out for a follow up period of 6 months.Significant diminution of pseudocholine esterase activity was noticed as early as the second week after infection, denoting defective synthetic function of the liver. Significant decrease of transaminases was also noticed during the fifth week, and showed correlation with the histopathological findings of cell necrosis. Glutamic oxalacetic transaminase appears to be a better index of liver cell integrity than glutamic pyruvic transaminase.Lactic dehydrogenase was only moderately diminished during the third and fourth months.Alkaline phosphatase was strikingly increased in hepatic schistosomiasis and occurred as early as the second week. Increased enzyme production and release in the circulation has been suggested.These results confirm the affection of the liver cell during infection with Schistosoma mansoni.     

Serum enzyme and tissue changes in shaven rabbits exposed to cold

Shaven rabbits were exposed to ?5 °C from 6 to 16 hr. With maximum exposure 50% became severely hypothermic, and the rest either became moderately hypothermic or remained normothermic. In severely hypothermic rabbits, marked elevations in serum concentrations of glutamic oxalacetic transaminase, glutamic pyruvic transaminase, aldolase, creatine phosphotransferase, and lactic dehydrogenase developed within 10–16 hr. Serum enzyme concentrations reached peak levels within 1 day after removal from cold and returned to normal within 6 days. Serum levels of isoenzyme lactic dehydrogenase 5 (SLDH₅) greatly increased and SLDH₁ decreased in severely hypothermic rabbits. This indicated that striated muscle tissue contributed to serum concentration of lactic dehydrogenase. About one-half of the rabbits showed foci of cardiac necrosis multiple pulmonary hemorrhages, and fatty changes in the liver, kidney, and striated and heart muscles. It is apparent that serum enzymes reached peak concentrations within the first day after cold exposure at a time when fatty changes and necrosis were found in the heart and other organs. The tissue changes were most frequent and severe in the hypothermic rabbits with the highest serum enzyme concentrations. Within 3–6 days fatty changes had largely disappeared, but the myocardial lesions persisted in the form of granulation and scar tissue.     

Dynamics of protozoan population density, plasma glutamic oxalacetic transaminase and plasma bilirubin concentrations during histomoniasis in turkeys

Density of populations of Histomonas meleagridis in ceca of infected turkeys was recorded daily for the first 17 days postinoculation with 20,000 protozoa. The major features of population growth were a 5-day lag period followed by rapid growth and plateau on the order 10⁷ protozoa/ml. Protozoan populations in hosts that failed to develop clinical histomoniasis remained close to the lag period density for the duration of the experiment. Plasma concentrations of glutamic oxalacetic transaminase (GOT) were found to be only weakly associated with the occurrence of clinical symptoms. Those results suggest that clinical symptoms are a cecal phenomenon, dependent on high population density of H. meleagridis. Evidence for elevation of both conjugated (direct) and protein-bound (indirect) bilirubin during histomoniasis suggests hemolytic jaundice, complicated with liver daage.     

Liver function tests during amoebic liver abscess formation in indomethacin-treated hamsters

Establishment of Entamoeba histolytica infection is facilitated through macrophage effector disruption by a prostaglandin E2 (PGE2)-mediated mechanism. Infection severity may be measured by weight of abscess formed. Indomethacin (Indo) treatment of infected hamsters reduced abscess weight by 30% at 7 days post-infection presumably by inhibition of PGE2. To explain reductions in abscess development by Indo treatment, we determined liver functionality in Indo-treated or untreated animals, either healthy or infected. Determinations of serum glutamic oxaloacetic (SGOT) and glutamic pyruvic (SGPT) transaminases, serum alkaline phosphatase (SAP), total serum protein (TSP), and bilirubinemia were done. SGOT, SGPT, and SAP activities showed a significant increase in their values by 600% at seven days post-infection in infected animals in both conditions; nonstatistical differences were found between animals treated or not. This increase did not correlate with the percentage of damage. Infected nontreated hamsters showed TSP levels 30% below normal group (P < 0.05). Infected Indo-treated hamsters had no significant differences compared to normal values. Infected nontreated animals showed an increase in bilirubin, particularly in indirect bilirubin, whereas infected Indo-treated hamsters showed total bilirubin values lower than normals (P < 0.05), with a decrease in direct bilirubin levels. Our results demonstrated that E. histolytica infection in hamsters produces similar abnormalities in liver function as it does in humans, and that the beneficial effect of Indo treatment on amoebic abscess development is not related with an improvement of liver functionality.     

Phylogenetic relationships among Eimeria spp. (Apicomplexa, Eimeriidae) infecting rabbits: evolutionary significance of biological and morphological features

Monophyly of all 11 valid Eimeria species from rabbits (Oryctolagus cuniculus Linnaeus, 1758) was revealed based on nuclear 18S rDNA sequence data. This finding implies that these species, which vary considerably in terms of their morphology and biology, diversified on a single host or several closely related species. Phylogenetic analysis divided rabbit Eimeria species into 2 sister lineages, corresponding to the presence/absence of the oocyst residuum. Other morphological or biological traits (oocyst shape and size, presence/absence of oocyst inner structures, pathogenicity, infection site, pre-patent and patent periods, sporulation time, and number of asexual generations) do not explicitly correlate with the phylogeny of rabbit coccidia.     

Factors influencing the fecal egg and oocyst counts of parasites of wild European rabbits Oryctolagus cuniculus (L.) in Southern Western Australia

Abundance of intestinal parasites was monitored by fecal egg and oocyst counts for samples of wild rabbits Oryctolagus cuniculus with different levels of imposed female sterility from 12 populations in southwestern Australia. Differences in egg counts of Trichostrongylus retortaeformis between seasons and age groups were dependent on the sex of the host. Pregnancy may have been responsible for these differences because egg counts were consistently higher in intact females than in females surgically sterilized by tubal ligation. Egg counts for Passalurus ambiguus were influenced by season and host age but there were no differences between sexes or between intact and sterilized female rabbits. No differences were detected in the oocyst counts of the 8 species of Eimeria between male and female rabbits or between intact and sterilized females. Seasonal differences were detected in oocyst counts of Eimeria flavescens and Eimeria stiedai. The overwhelming determinant of coccidian oocyst counts was host age, with 6 species being much more abundant in rabbits up to 4 mo of age. There was a suggestion that egg counts of T. retortaeformis and oocyst counts of several species of Eimeria were reduced in populations where rabbit numbers had been depressed for at least 2 yr, but there was no evidence that short-term variations in rabbit numbers had a measurable effect on parasite abundance.     

Characterization of Eimeria species. I. Isolation and study of pathogenicity of a pure strain of Eimeria perforans (Leuckart, 1879; Sluiter and Swellengrebel, 1912)

Eimeria perforans was isolated in pure strain by utilizing specific biological characters and specific-pathogen free rabbits. The purity of this strain was demonstrated by measurements of oocysts, derived from a line, started by infection from a single oocyst. The parasite, when inoculated in large numbers, causes a mild disease response for only about two days.     

Conservation of proteins involved in oocyst wall formation in Eimeria maxima, Eimeria tenella and Eimeria acervulina

Vaccination with proteins from gametocytes of Eimeria maxima protects chickens, via transfer of maternal antibodies, against infection with several species of Eimeria. Antibodies to E. maxima gametocyte proteins recognise proteins in the wall forming bodies of macrogametocytes and oocyst walls of E. maxima, Eimeria tenella and Eimeria acervulina. Homologous genes for two major gametocyte proteins - GAM56 and GAM82 - were found in E. maxima, E. tenella and E. acervulina. Alignment of the predicted protein sequences of these genes reveals that, as well as sharing regions of tyrosine richness, strong homology exists in their amino-terminal regions, where protective antibodies bind. This study confirms the conservation of the roles of GAM56 and GAM82 in oocyst wall formation and shows that antibodies to gametocyte antigens of E. maxima cross-react with homologous proteins in other species, helping to explain cross-species maternal immunity.     

Activities of twelve enzymes in the blood plasma of rainbow trout and tench subjected to various forms of thermal disturbance

The levels of ornithine carbamyl transferase, acid phosphatase, alkaline phosphatase, leucine amino peptidase, creatine kinase, amylase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, lactate deshydrogenase, hydroxybutyrate deshydrogenase, glutamate deshydrogenase and malate deshydrogenase were determined in the plasma of Rainbow Trout and Tench submitted to water temperature increases. In the Rainbow Trout a thermal shock from 12 to 21 degrees, increases activities of some enzymes while temperature increase up to pre-mortem stage causes very important changes in enzymatic levels. In the Tench a thermal shock from 12 to 28 degrees causes more changes of enzymatic activities than a shock from 12 to 25 degrees. In Tench acclimated to 25 degrees, various enzyme levels are increased in comparison with 12 degrees control animals. A high potassium level in water causes complex changes in enzyme levels. The most sensitive enzymes to thermal disturbance are GOT and GPt transaminases which increase whatever the aggression form, amylase when thermal disturbance is moderate, alkaline phosphatase and malate deshydrogenase in case of strong thermal stress. The study of these enzymes is recommended for watching the state of fishes living in artificially heated waters.     

Concurrence of Eimeria and helminth parasitic infections in West African Dwarf kids in Ghana

The sequence of appearance of Eimeria and helminths, in 20 West African Dwarf kids from birth and the pattern of oocyst and strongyle worm egg output for 1.5 years are described. Eimeria oocysts appeared early about 20 days after birth and oocyst output in some kids reached 2.7 million oocysts per gram (opg) of faeces about 39 days after birth and showed a group mean oocyst output of 443,540 opg in the second month but this declined further to 23,840 opg after 5.5 months. Eimeria arloingi (20.50%), Eimeria ninakohlyakimovae (17.02%), Eimeria alijevi (15.07%), Eimeria caprina (12.65%), Eimeria jolchijevi (11.42%), Eimeria apsheronica (8.70%), Eimeria pallida (5.31%), Eimeria caprovina (3.29%), Eimeria hirci (3.20%) and Eimeria christenseni (2.84%) were seen in a descending order of prevalence. Strongyle worm ova were seen 53 days after birth and peaked soon after the fall in Eimeria oocyst output but thereafter fluctuated. The eggs of cestode, Moniezia spp. appeared later but was transient. Both oocyst and worm egg output declined and were almost absent when the kids were about 1 year old. Faecal larval cultures were made and the L₃s identified with the dominant ones being Haemonchus spp. and Trichostrongylus spp. Sixty percent of the kids in this study died when they were 7 months old and a total of 70% of the kids had died before they were 1 year old.     

Quantification of the crowding effect during infections with the seven Eimeria species of the domesticated fowl: its importance for experimental designs and the production of oocyst stocks.

The 'crowding effect' in avian coccidia, following administration of graded numbers of sporulated oocysts to na?ve hosts, is recognisable by two characteristics. First, increasing doses of oocysts give rise to progressively higher oocyst yields, until a level of infection is reached (the 'maximally producing dose') above which further dose increases result in progressive decreases in oocyst yields. Second, the number of oocysts produced per oocyst administered (the 'reproductive potential') tends to decrease as the oocyst dose is increased. The dose that gives the maximal reproductive potential is the 'crowding threshold' and doses exceeding this are 'crowded doses'. Graded doses of Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox or Eimeria tenella were given to chickens of the same breed, sex and age, reared on the same diet, under identical management. The two characteristics of the crowding effect were demonstrated graphically and, by interpolation, the estimated crowding thresholds were 903, < or =16, 39, < or =14, < or =16, < or =16 or 72 sporulated oocysts, respectively, for the seven Eimeria species enumerated above. This is apparently the first report of definitive experiments to quantify a crowding effect in E. brunetti, E. maxima, E. mitis, E. necatrix and E. praecox. Maximum experimental reproductive potentials were considerably lower than the theoretical reproductive potentials for all seven species. The interaction between availability of host intestinal cells and immunity contributing to the crowding effect is discussed. Standard curves obtained under specified conditions should be used to estimate appropriate infective doses for experimental designs or in vivo production of oocyst stocks. For experiments on effects of chemotherapy or immunisation on oocyst production, an infective dose lower than the crowding threshold should be used. For efficient production of laboratory or factory oocyst stocks, the maximally producing dose (which is greater than the crowding threshold), should be used.     

Eimeria (Protozoa: Eimeriidae) of the Cottontail Rabbit Sylvilagus audubonii in Northeastern Colorado, with Descriptions of Three New Species

SYNOPSIS. All of 100 cottontail rabbits Sylvilagus audubonii were found to be infected with 1-6 species of Eimeria. Three new species, E. audubonii, E. neoirresidua and E. poudrei are described from this host. Sub-spherical oocysts of E. audubonii average 21.2 by 17.1 μ; polar body, micropyle, oocyst residuum and sporocyst residuum are all absent; ellipsoidal sporocysts average 12.9 by 5.8 μ. Ovoid to ellipsoidal oocysts of E. neoirresidua average 25.7 by 17.9 μ; polar body and oocyst residuum are absent; micropyle and sporocyst residuum are present; ellipsoidal sporocysts average 14.5 by 6.4 μ. Ovoid to ellipsoidal oocysts of E. poudrei average 26.0 by 18.1 μ; polar body is lacking; micropyle, oocyst residuum and sporocyst residuum are present; ellipsoidal sporocysts average 14.4 by 6.4 μ. Three species of Eimeria previously described in the literature, E. maior Honess, 1939, E. media form honessi Carvalho, 1943 and E. environ Honess, 1939 are redescribed. A detailed structural and statistical analysis of each species is presented with at least 200 sporulated oocysts measured in each instance. A host list and a key to the Eimeria of cottontails is given. The use of detailed studies of oocyst size and structure as a tool for specific diagnosis of the Eimeria of cottontails is discussed.     

Enzyme activities in the plasma of rainbow trout, Salmo gairdneri Richardson; the effects of nutritional status and salinity

The levels of lactate dehydrogenase, hydroxy butyric dehydrogenase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, glutamate dehydrogenase, alkaline phosphatase and leucine amino peptidase were determined in the plasma of rainbow trout. The protein concentration and the amount of alkaline phosphatase were reduced in starving trout. Fed trout showed reduced lactate dehydrogenase activity. There was a significant correlation between the condition factor, most of the enzyme activities and the protein concentration. At 10 parts per thousand salinity the activities of alkaline phosphatase and leucine amino peptidase were significantly elevated, while lactate dehydrogenase activity was significantly decreased.     

Intracellular localization of nitrate reductase, nitrite reductase, and glutamic Acid dehydrogenase in green leaf tissue

Greenhouse grown seedlings of corn (Zea mays L.) and foxtail (Setaria faberii Herrm.) were used as source material in determining the intracellular localization of nitrate reductase, nitrite reductase, and glutamic acid dehydrogenase, Nonaqueous and aqueous isolation techniques were used to establish that nitrite reductase is localized within the chloroplasts, but that nitrate reductase and glutamic acid dehydrogenase are not. Nonaqueous isolation gives distribution patterns of nitrite reductase which are the same as those observed for NADP-dependent 3-phosphoglyceraldehyde dehydrogenase but which differ drastically from the patterns observed for pyruvic acid kinase. The distribution patterns for nitrate reductase are the same as those of pyruvic acid kinase. The techniques used do not eliminate the possibility that nitrate reductase and pyruvic acid kinase are localized on the external chloroplast membrane.

The data obtained establish that glutamic acid dehydrogenase of green leaves is localized within the mitochondria.

     

Enzyme activities in the serum of rainbow trout,Salmo gairdneri Richardson; the effects of water temperature*

Activities of lactate dehydrogenase, hydroxy butyric dehydrogenase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, glutamate dehydrogenase, creatinine kinase, alkaline phosphatase, and leucine amino peptidase were determined in the sera of rainbow trout. The animals had previously been adapted to temperatures of 3.5, 6, 8, 10, 12.5, 15, 17, 19, 21.5 and 23° C. Most of the enzyme activity increased with the rise in temperature. The activity of alkaline phosphatase decreased in the range 6–19° C, while the changes in the glutamate dehydrogenase activity took a complex course. The results are compared with the findings of other authors.     

Effect of static magnetic field on some enzymes activities in rats

The magnetic field of 0.008 T and 0.15 T inductions influence lasting 7 weeks (7 days a week), 1 h daily determines the increase of the activity of cytoplasmatic enzymes (glutamic pyruvic transaminase, glutamic oxalacetic transaminase, lactic dehydrogenase), the decrease of cholinesterase activity and the growth of alkaline phosphatase activity in the plasma of the examined animals. The observed changes were reversible. 2 months after the exposure had been stopped, the tested parameters were back to normal.     

Montanide™ ISA 71 VG adjuvant enhances antibody and cell-mediated immune responses to profilin subunit antigen vaccination and promotes protection against Eimeria acervulina and Eimeria tenella

The present study was conducted to investigate the immunoenhancing effects of Montanide™ ISA 71 VG adjuvant on profilin subunit antigen vaccination. Broiler chickens were immunized subcutaneously with a purified Eimeria acervulina recombinant profilin protein, either alone or mixed with ISA 71 VG, and host immune responses were evaluated. After secondary immunization, antigen-specific antibody and T-cell responses were higher in the group which received profilin plus ISA 71 VG compared with the other groups. Furthermore, body weight gains and fecal oocyst shedding were evaluated following oral challenge infection with live E. acervulina or Eimeria tenella oocysts. Vaccination with profilin plus ISA 71 VG reduced oocyst shedding compared with animals immunized with profilin alone. These results demonstrate that the recombinant profilin subunit vaccine, when given in combination with Montanide™ ISA 71 VG, augments protective immunity against E. acervulina and E. tenella.