W. R. Kelly

Bio: W. R. Kelly is an academic researcher from University of Queensland. The author has contributed to research in topics: Clostridium perfringens & Clostridium perfringens epsilon toxin. The author has an hindex of 24, co-authored 66 publications receiving 1745 citations. Previous affiliations of W. R. Kelly include Universidade Federal de Minas Gerais.

Improved competitive enzyme immunoassay for the diagnosis of bovine brucellosis.

Abstract: A modification of the competitive enzyme-linked immunosorbent assay (C-ELISA) for differentiating the antibody response of cattle vaccinated with Brucella abortus strain 19 and B. abortus infected cattle is described. This assay utilizes lipopolysaccharide as the antigen, immobilized on a polystyrene matrix, and a monoclonal antibody (M84) with specificity for an epitope of the O-polysaccharide. A goat anti-mouse IgG antibody-enzyme conjugate is used for detection. The specificity of the modified assay was 99.7% when 1446 sera from brucellosis free herds were tested and it correctly identified 636 sera from B. abortus infected cattle as positive, using a cut-off of 30% inhibition, for a sensitivity estimate of 100%. No reactions were noted among 261 sera from vaccinated cattle. However, in testing 1147 sera that gave positive reactions in the buffered plate antigen test, the indirect ELISA, the complement fixation test or a combination of these tests from the serum bank, 31 gave positive reactions. Twenty-seven of the 31 sera originated from recently vaccinated cattle. The overall specificity for sera from vaccinated cattle was 97.3%. Because of the sensitivity and specificity of this procedure and its ease of performance, it would be a reasonable alternative as a single assay for serological diagnosis of brucellosis.

Comparison of enzyme immunoassays for the diagnosis of bovine brucellosis

Abstract: The indirect enzyme immunoassay for measurement of bovine antibody to Brucella abortus was tested on 15 716 Canadian sera to assess the specificity. These sera were also tested by the buffered plate antigen test. Two enzyme-linked immunosorbent assay (ELISA) formats were used for assessment of data: the targeting procedure using a positive control serum allowed to develop to an optical density of 1.0 and the use of a positive control serum to determine relative positivity at a set time. Two different cut-off values were also assessed for each assay. A total of 763 sera gave reactions above established cut-off values in the ELISA while 216 were positive in the buffered plate antigen test (BPAT). A modification of the indirect ELISA employed divalent cation chelating agents (EDTA/EGTA) incorporated into the serum incubation stage to eliminate some non-specific reactions. This method was applied only to the 763 indirect ELISA reactor sera and it eliminated all but 93 or 37, depending on the cut-off selected, of the reactions. Sensitivity was assessed by testing 424 sera from B. abortus culture positive cattle. The indirect ELISA classified all 424 sera as positive by either method of data handling and with or without addition of EDTA/EGTA for a specificity estimate of 100%. In the BPAT, 412 sera gave a positive agglutination reaction. Ten percent of the 15 716 sera were randomly selected and tested by two different competitive ELISAs and by the complement fixation test. One competitive ELISA used B. abortus O -polysaccha-ride as the antigen and an enzyme conjugated monoclonal antibody to the O -polysaccharide for competition and detection. Of the sera tested, 34 gave false positive reactions. On a retest, the false positive reactions were reduced to two. The second competitive ELISA used lipopolysaccharide as the antigen, a different monoclonal antibody but also specific for the O -polysaccharide for competition and commercially available goat anti-mouse IgG enzyme conjugate for detection. In the initial assessment, this test gave rise to five false positive reactions. This number was reduced to two when retesting the sera. The complement fixation test used was a micro format test and three sera gave false positive reactions. A total of 654 sera from animals from which B. abortus was isolated was tested by the first competitive ELISA. Of these, nine sera were negative on the initial test. This number was reduced to three on repeat testing. All 636 sera tested by the second competitive ELISA were positive. Fifteen of 636 sera gave sufficient prozoning in the complement fixation test to be considered diagnostically negative and 59 sera were anticomplementary. Sensitivity and specificity are summarized in the table. Cut-off values for each assay were initially established by visual observation of frequency distributions of positive and negative serum samples. These cut-off values were confirmed by receiver operating characteristics (ROC) analysis. In addition, an index of performance ( accuracy ) was established for each assay in order to allow direct comparison. Accuracy estimates were based on the sensitivity, specificity and disease prevalence for the data.

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

Abstract: 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.

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

Abstract: 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.

Report of a case and review of the literature

Abstract: Summary. A case of paraganglioma of the filum terminale is presented where normal sympathetic ganglion cells were seen in conjunction with tumour cells in a well-encapsulated tumour, suggesting a possible origin from heterotopic sympathetic ganglion.

Report of a Case and Review of the Literature

Abstract: (2) peculiar "taming" effect on monkeys in that aggression disappears, and (3) thalamic stimulation.2 Although the drug has been in clinical use since 1954, reports of toxicity have been scattered, and only one review of adverse responses has appeared.3 One death has been reported.4 The purpose of this communication is to present a case of meprobamate idiosyncrasy with skin bi¬ opsy and skin testing, to review the pub¬ lished reports to date, and to discuss possible etiologic factors in the pathogene¬ sis of the anaphylactoid reaction. The records of more than 6500 patients have been summarized to date.8"81 Twentythree cases of attempted suicide,6"19 and one hundred thirteen cases of idiosyncrasy have

OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals

Abstract: The most recent version of the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals (the Terrestrial Manual) is online: http://www.oie.int/en/international...

Ivermectin and abamectin.

Abstract: Ivermectin and abamectin, members of the avermectin family of compounds, were introduced to the market in the 1980's as a veterinary antiparasitic drug and agricultural pesticide, respectively. Their acceptance and commercial success have been remarkable; both are highly effective and in worldwide use. The efficacy of ivermectin in river blindness has expanded the interest in its use in human medicine. In response to the intense scientific and industrial interest in ivermectin and abamectin and the likelihood that they will be forerunners of an expanding family of drugs, this comprehensive monograph satisfies the need for a review and synthesis of current knowledge about the use of these substances in crop protection as well as in cattle, sheep, swine, horses, dogs, cats, birds, fish, reptiles, and in man. This overview presents chemical, biochemical, and microbiological data, as well as pharmacological, safety, and environmental aspects and covers practical use of the compounds as antiparasitic and pesticide agents, as well as the available safety data that have emerged from the clinical experience with human applications.

Rhodococcus equi: an animal and human pathogen.

Abstract: Recent isolations of Rhodococcus equi from cavitatory pulmonary disease in patients with AIDS have aroused interest among medical microbiologists in this unusual organism. Earlier isolations from humans had also been in immunosuppressed patients following hemolymphatic tumors or renal transplantation. This organism has been recognized for many years as a cause of a serious pyogranulomatous pneumonia of young foals and is occasionally isolated from granulomatous lesions in several other species, in some cases following immunosuppression. The last decade has seen many advances in understanding of the epidemiology, pathogenesis, diagnosis, treatment, and immunity to infection in foals. The particular susceptibility of the foal is not understood but can be explained in part by a combination of heavy challenge through the respiratory route coinciding with declining maternally derived antibody in the absence of fully competent foal cellular immune mechanisms. R. equi is largely a soil organism but is widespread in the feces of herbivores. Its growth in soil is considerably improved by simple nutrients it obtains from herbivore manure. About one-third of human patients who have developed R. equi infections had contact in some way with herbivores or their manure. Others may have acquired infection from contact with soil or wild bird manure. R. equi is an intracellular parasite, which explains the typical pyogranulomatous nature of R. equi infections, the predisposition to infection in human patients with defective cell-mediated immune mechanisms, and the efficacy of antimicrobial drugs that penetrate phagocytic cells.