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Biomedical subjects

W R Kelly

Publications and source records attributed to W R Kelly.

At least 19 recordsLinked to original sources
PubMed2004

The pathology of peracute experimental Clostridium perfringens type D enterotoxemia in sheep.

The pathological findings in sheep with peracute experimental Clostridium perfringens type D enterotoxemia are described. Of 16 animals inoculated intraduodenally with a whole culture of this microorganism and a starch solution in the abomasum, 12 developed clinical signs including increased respiratory efforts, recumbency, paddling, bleating, convulsions, blindness, and opisthotonus. Diarrhea was not observed in any of the animals. The time lapse between the beginning of intraduodenal infusion and onset of clinical signs varied between 30 minutes and 26 hours, and the clinical course varied between 1 and 9 hours. Gross postmortem changes were observed in these 12 animals and included pulmonary edema; excess pericardial, peritoneal, or pleural fluid with or without strands of fibrin; liquid small intestinal contents; leptomeningeal edema; cerebellar coning; and subcapsular petechiae on kidneys. Histological changes consisted of severe edema of pleura and interlobular septa and around blood vessels and airways and acidophilic, homogeneous, proteinaceous perivascular edema in the brain. Five of 12 animals (42%) with clinical signs consistent with enterotoxemia lacked specific histological lesions in the brain. None of the intoxicated or control animals developed nephrosis. Glucose was detected in the urine of 3 of 6 animals that were tested for this analyte. These results stress the importance of the use of histological examination of the brain, coupled with epsilon toxin detection, for a definitive diagnosis of C. perfringens type D enterotoxemia in sheep.

Animals↗
PubMed2003

Comparison of four techniques for the detection of Clostridium perfringens type D epsilon toxin in intestinal contents and other body fluids of sheep and goats.

Polyclonal capture enzyme-linked immunosorbent assay (PC-ELISA), monoclonal capture ELISA (MC-ELISA), mouse neutralization test (MNT), and counterimmunoelectrophoresis (CIEP), were compared for their ability to detect epsilon toxin in intestinal contents and body fluids of sheep and goats. When used to evaluate intestinal contents of sheep artificially spiked with epsilon prototoxin, PC-ELISA detected 0.075 mouse lethal dose (MLD)50/ml, whereas the MNT, MC-ELISA, and CIEP detected 6, 25, and 50 MLD50/ml, respectively. Amounts of epsilon toxin detected by PC-ELISA, MC-ELISA, MNT, and CIEP in sheep pericardial fluid artificially spiked with epsilon prototoxin were 0.075, 0.75, 6, and 200 MLD50/ml, respectively. For assaying epsilon toxin in aqueous humor, PC-ELISA and MC-ELISA detected 0.075 MLD50/ml, whereas CIEP detected 200 MLD50/ml (MNT was not evaluated). When 51 samples of intestinal contents of sheep and goats (32 positive and 19 negative to MNT) were analyzed by the other 3 techniques, the relative sensitivity of PC-ELISA, MC-ELISA, and CIEP was 93.75, 84.37, and 37.50%, respectively. The specificity of PC-ELISA, MC-ELISA, and CIEP was 31.57, 57.89, and 84.21%, respectively. The absolute sensitivity of PC-ELISA, MC-ELISA, CIEP, and MNT was 90.90, 69.69, 15.15, and 54.54%. The absolute specificity of the 4 techniques was 100%. These results show that there is a marked inconsistency among techniques routinely used to detect Clostridium perfringens epsilon toxin. Until more consistent results are achieved, the diagnosis of enterotoxemia should not only be based solely on epsilon toxin detection, but also on clinical and pathological data.

Animals↗
PubMed2002

A study of "white spotted kidneys" in cattle.

A study was performed at an abattoir in Australia, in an attempt to correlate focal chronic interstitial nephritis (FCIN) producing the so-called "white spotted kidney", with Leptospira spp. and other pathogens in cattle. Samples of kidneys, urine and blood were collected immediately after slaughter from 46 two-year-old heifers, and 72 cows and bulls with gross lesions consistent with FCIN. The same samples were also collected from nine heifers and 12 cows with no gross kidney lesions. Aqueous humour was also collected from the eye of 17 of the adult animals. The sera were processed by a microscopic agglutination test for leptospira antibodies, while all the other samples were cultured for Leptospira spp. and also processed for routine aerobic and anaerobic culture for other pathogens. Sub-samples from all the kidneys were fixed in 10% buffered formalin and processed histologically. Antibody titers of 1:400 or higher for Lepstospira borgpeterseni serovar hardjo were found in six adult animals with FCIN and in one adult animal with no gross kidney changes, while antibody titers of 1:400 to L. borgpeterseni serovar tarassovi were found in only one animal with FCIN. L. borgpeterseni serovar hardjo was isolated from the urine and kidney of one adult animal and from the urine of another adult animal, both with FCIN. No pathogens were isolated from any of the other samples. The histological lesions were consistent in most cases with FCIN. The results suggest that neither Leptospira spp. nor active infection by other bacteria are associated with the so-called "white spotted kidneys".

Abattoirs↗
PubMed2002

Effects of intravenous injection of Clostridium perfringens type D epsilon toxin in calves.

In cattle, a neurological lesion similar to that produced in sheep and goats by Clostridium perfringens type D enterotoxaemia has been reported. However, no causal relationship has been established between this disease and the lesion in cattle. The effects of single and multiple intravenous injections of epsilon toxin in three calves aged 6 months were studied. A further calf was inoculated intravenously with saline solution and used as a control. Epsilon toxin invariably produced neurological signs within 2-60 min of the end of the injection process. Clinical signs consisted of loss of consciousness, recumbency, convulsions, paddling, opisthotonus, hyperaesthesia and dyspnoea. Gross changes consisted of severe acute pulmonary oedema, which was particularly marked in the interlobular septa. The histological lesions consisted of intra-alveolar and interstitial oedema of the lung and variable degrees of perivascular proteinaceous oedema in the internal capsule, thalamus and cerebellar white matter. No clinical or post-mortem changes were observed in the control calf. These results show that calves are susceptible to the intravenous injection of epsilon toxin, and that they can show at least some of the histological lesions produced in sheep and goats by this toxin.

Acute Disease↗
PubMed2001

An alternative method for the certification of the sulfur mass fraction in coal Standard Reference Materials.

The S mass fractions of coal SRMs 2682b, 2684b, and 2685b are certified by direct comparison with coal SRMs 2682a, 2684a, and 2685a, respectively, using high-temperature combustion analysis with infrared (IR) absorption detection. The S mass fractions of the "a" materials used for calibration were previously determined by means of isotope-dilution thermal-ionization mass spectrometry (ID-TIMS). Therefore, the comparisons performed with the combustion-IR absorption method establish direct traceability links to accurate and precise ID-TIMS measurements. The expanded uncertainties associated with the certified S mass fractions are of approximately the same magnitude as would be expected for the ID-TIMS methodology. An important aspect of these certifications is that each "b" material is essentially identical with the corresponding "a" material, because both were produced from the same bulk, homogenized coal. As a test of the efficacy of the new certification approach when calibrant and unknown are not identical, the S mass fraction of coal SRM 2683b has been determined by direct comparison to coal SRM 2683a. These two coals, which have both previously been analyzed with ID-TIMS, are different in terms of S content and other properties. Whereas the S mass fraction for SRM 2683b determined with the new methodology agrees statistically with the ID-TIMS value, there is reason for caution in such cases. In addition to the usefulness of the alternative approach for certification activities within NIST, this approach might also be an excellent way of establishing NIST traceability during the value assignment process for reference materials not issued by NIST. Further research is needed, however, to understand better the scope of applicability.

Journal Article↗
PubMed2000

An apparent outbreak of cutaneous papillomatosis in merino sheep in patagonia, Argentina.

A retrospective study was performed on skin samples from an outbreak of cutaneous papillomatosis in Merino sheep that occurred in 1995. The samples were processed for routine histology, electron microscopy and immunocytochemistry for papilloma viruses. Particles of approximately 55 nm diameter were found in some nuclei of the stratum granulosum cells, while immunocytochemistry gave positive staining of cell nuclei in this layer. This study confirms that papillomas associated with papillomaviruses occur in sheep in Patagonia.

Animals↗
PubMed1999

Antibody response in goats vaccinated with liposome-adjuvanted Clostridium perfringens type D epsilon toxoid.

A trial was performed using 20 goats to evaluate the antibody responses to a liposome-adjuvanted Clostridium perfringens epsilon toxoid vaccine (LIPV). The antibody response was compared with those produced by epsilon toxoid vaccines prepared using aluminium hydroxide (ALV) and incomplete Freud's adjuvant (FAV). The animals were allocated to four groups at the beginning of the trial. The animals in group 1 were vaccinated with ALV, while the animals in group 2 received FAV and those in groups 3 and 4 were vaccinated with LIPV. The animals in groups 1 to 3 received three doses of the corresponding vaccine at intervals of three weeks, while those in group 4 received only 1 dose of vaccine at the beginning of the trial. A blood sample was obtained from all the goats at the beginning of the trial and then weekly for 8 weeks. The samples were analysed for epsilon toxoid antibodies by an indirect ELISA technique. No major clinical abnormalities were observed in the animals after vaccination, with the exception of those that received the FAV, which experienced transient lameness. The highest antibody response was observed in the animals vaccinated with FAV, but they presented moderate to severe inflammatory tissue reactions at the injection site. Moderately high antibody responses were obtained with the ALV, with which only minor local reactions were observed. No significant antibody responses were obtained with the LIPV, nor were local reactions observed.

Aluminum Hydroxide↗
PubMed1999

Resistance of ovine, caprine and bovine endothelial cells to Clostridium perfringens type D epsilon toxin in vitro.

Ovine, caprine and bovine endothelial cells were grown in vitro and challenged with Clostridium perfringens type D epsilon toxin to compare their susceptibility to this toxin. Madin Darby canine kidney (MDCK) cells, which are known to be susceptible to epsilon toxin, were used as a positive control. No morphological alterations were observed in any of the endothelial cell cultures tested, even after challenging with doses as high as 1200 MLD50/ml of epsilon toxin. MDCK cells showed contour rounding and nuclear condensation as early as 30 min after exposure to 100 MLD50/ml of epsilon toxin and after 60 min of exposure to 12.5 MLD50/ml of the same toxin. All the MDCK cells were dead after 3 h of exposure to all concentrations of epsilon toxin. The results indicate that ovine, caprine and bovine endothelial cells are not morphologically responsive to the action of epsilon toxin in vitro.

Animals↗
PubMed1999

PCR detection of Clostridium perfringens type D in formalin-fixed, paraffin-embedded tissues of goats and sheep.

A polymerase chain reaction (PCR) was used to identify the genes encoding the alpha, epsilon and beta toxins of Clostridium perfringens in formalin-fixed, paraffin-embedded intestinal tissues of goats and sheep. When pure cultures of Cl. perfringens types B and D were used as control templates in the PCR, products of the following sizes were observed on the agarose gel: 247 bp (alpha primers), 1025 bp (beta primers) and 403 bp (epsilon primers). When used to identify Cl. perfringens type D in formalin-fixed, paraffin-embedded intestinal tissues of goats and sheep, the PCR technique resulted in the detection of this micro-organism in 11 out of 13 samples known to be infected with Cl. perfringens. No false positive results were obtained when 13 culturally negative samples were analysed by the PCR technique.

Animals↗
PubMed1999

Comparison of the effects of Clostridium perfringens type D culture supernates in ligated intestinal loops of goats and sheep.

The effects of Clostridium perfringens type D culture supernates were compared in ligated loops of the small intestine (ileum) and colon of four goat kids and four lambs, the loops being examined histopathologically and electron microscopically 7 h after inoculation. No lesions were observed in the small intestine of any animal, or in control colonic loops. In the caprine and ovine colonic loops treated with culture supernates, most goblet cells were empty and the lumina contained a layer of mucus, polymorphonuclear leucocytes, bacteria and sloughed epithelial cells. The apical cytoplasm of the superficial epithelial cells was lost. Moderate oedema was observed in the submucosa and muscular layer. The colonic lesions were more severe in kids than in lambs. No changes were seen in vascular endothelial cells in any loop. 1999 W.B. Saunders and Company Ltd.

Animals↗
PubMed1998

Variability of serum antibody responses of goat kids to a commercial Clostridium perfringens epsilon toxoid vaccine.

Twenty-nine Angora goats were used in a trial of a commercial enterotoxaemia (pulpy kidney disease) vaccine. The animals were allocated to four groups, of which three received an initial dose of vaccine, two also received a booster of the same vaccine either 28 or 42 days after the first vaccination, and the fourth remained as an unvaccinated control group. An indirect ELISA technique was used to measure the titres of Clostridium perfringens type D epsilon antitoxin in serum samples taken before vaccination and 17, 28, 42, 59, 70, 86, 98 and 128 days after vaccination. There was a wide range of antibody titres after vaccination, and the great majority of the vaccinated animals had titres below the protective level, arbitrarily set at 0.25 iu/ml, by day 98.

Animals↗
PubMed1998

Protection of goats against experimental enterotoxaemia by vaccination with Clostridium perfringens type D epsilon toxoid.

Enterotoxaemia in goats is mainly characterized by enterocolitis, and it has been suggested that the poor efficacy of commercial vaccines in preventing the disease is due to the local action of Clostridium perfringens toxin/s within the intestine, where circulating antibodies might not exert their action. Five goat kids were vaccinated with an incomplete Freund's adjuvant C perfringens type D epsilon toxoid vaccine on three occasions at three-week intervals, four similar kids were vaccinated with a commercial enterotoxaemia vaccine at the same times, and five other unvaccinated kids were used as controls. All the animals were challenged intraduodenally, one week after the last vaccination, with C perfringens type D filtered culture supernatant. At the time of challenge, the level of epsilon toxin antibodies in the serum of the Freund's adjuvant-vaccinated kids ranged between 2.45 and 230 iu/ml, while the kids that received the commercial vaccine had levels between 0.22 and 1.52 iu/ml. No clinical or postmortem changes were observed in the kids that received the Freund's adjuvant-vaccine. Three of the four kids that received the commercial vaccine developed mild, pasty diarrhoea, with a slight reddening of the colonic mucosa being observed postmortem. All the unvaccinated kids developed severe diarrhoea, respiratory distress and central nervous system signs, and were killed humanely between six and 24 hours after challenge. The postmortem changes consisted of pseudomembranous colitis, lung oedema and perivascular oedema of the brain. Moderate to high serum levels of anti-epsilon antibody appeared to protect the goats against both the systemic and the intestinal effects of C perfringens type D toxins.

Animals↗
PubMed1998

Lesions caused by cardiovascular flukes (Digenea: Spirorchidae) in stranded green turtles (Chelonia mydas).

Evidence of infection with spirorchid flukes (Digenea: Spirorchidae) was sought at necropsy of 96 stranded green turtles, Chelonia mydas, that were examined during the course of a survey of marine turtle mortality in southeastern Queensland, Australia. Three species of spirorchid (Hapalotrema mehrai, H. postorchis, and Neospirorchis schistosomatoides) were identified. Severe disease due to spirorchid fluke infection (spirorchidiasis) was implicated as the principal cause of mortality in 10 turtles (10%), and appeared to be one of multiple severe problems in an additional 29 turtles (30%). Although flukes were observed in only 45% of stranded C. mydas in this study, presumed spirorchid fluke infection was diagnosed in an additional 53% of turtles, based principally on characteristic necropsy lesions and to a lesser extent on the histopathological detection of spirorchid eggs. Characteristic necropsy lesions included miliary spirorchid egg granulomas, which were observed most readily on serosal surfaces, particularly of the small intestine. Cardiovascular lesions included mural endocarditis, arteritis, and thrombosis, frequently accompanied by aneurysm formation. Resolution of thrombi was observed to occur via a combination of granuloma formation about indigestible components (spirorchid fluke egg shells) and exteriorization through the vessel wall, which resulted in granulomatous nodules on the adventitial surface. Septic aortic thrombosis complicated by disseminated bacterial infection, observed in five turtles, was recorded for the first time. Egg granulomas were ubiquitous in turtle tissues throughout this study. Although they generally appeared to be mild or incidental lesions, they were occasionally associated with severe multifocal granulomatous pneumonia or meningitis.

Animals↗
PubMed1998

Experimental Clostridium perfringens type D enterotoxemia in goats.

The effects of intraduodenal administration of Clostridium perfringens cultures and culture products in goats were evaluated to develop a reliable experimental model of enterotoxemia in this species. Five conventionally reared, 11-16-week-old Angora goat kids were dosed intraduodenally with whole cultures of C. perfringens type D; five similar animals were dosed with C. perfringens type D filtered culture supernatant; and a third group of five kids was dosed with C. perfringens type D washed cells. Two kids were used as controls and received sterile, nontoxic culture medium intraduodenally. All animals received starch solution into the abomasum. All five kids inoculated with whole culture and three of five dosed with culture supernatant and with washed cells developed central nervous system signs. Diarrhea was observed in two of five kids inoculated with whole culture, in all five of those dosed with culture supernatant, and in three of five of those that received washed cells. The most striking postmortem findings consisted of lung edema, necrotizing pseudomembranous colitis, and cerebral vasogenic edema. The protocol thus provided a reasonable model of naturally occurring enterotoxemia in goats, producing a range of clinical signs and postmortem changes similar to those observed in the natural disease.

Abomasum↗
PubMed1997

Caprine enterotoxaemia associated with cerebral microangiopathy.

Cerebral microangiopathy is described in naturally occurring clostridial enterotoxaemia in two goats. The two cases were selected from the files of two diagnostic laboratories in Australia, on the basis that the clinical syndrome and history were consistent with a diagnosis of enterotoxaemia, and that the diagnosis was confirmed by the identification of epsilon toxin in the intestinal contents. The lesions consisted of acute perivascular proteinaceous exudate in the brain and bilaterally symmetrical foci of encephalomalacia were observed in one of the goats. These brain lesions confirm that Clostridium perfringens type D enterotoxaemia may produce histologically detectable brain changes in goats.

Animals↗