Agar Gel Diffusion Test Research Articles

Antibody response to and maternal immunity from an experimental psittacine beak and feather disease vaccine

SUMMARY Adult umbrella cockatoos, Moluccan cockatoos, African grey parrots, and a yellow-headed Amazon parrot were inoculated im or sc with β-propiolactone-treated psittacine beak and feather disease (pbfd) virus. Thirty- to 45-day-old African grey parrot, umbrella cockatoo, and sulphur-crested cockatoo chicks also were vaccinated with the same inoculum. The hemagglutination inhibition (hi) and agar-gel diffusion tests were used to assay for post-vaccination development of anti-pbfd virus antibodies. All adult vaccinates seroconverted and had increases in hi and precipitating antibodies. The vaccinated chicks had increased concentrations of hi antibodies, but precipitating antibodies could not be detected. To demonstrate that chicks from vaccinated hens are protected from pbfd virus challenge, 3 African grey parrot chicks and 2 umbrella cockatoo chicks from vaccinated hens and 1 African grey parrot chick and 1 umbrella cockatoo chick from nonvaccinated hens were exposed to purified pbfd virus. Chicks from the vaccinated hens remained clinically normal during the 50-day test period. Chicks from the nonvaccinated hens developed clinical and histologic lesions of pbfd. Infected tissues from these birds were confirmed to contain viral antigen, using immunohistochemical staining techniques. The pbfd virus was recovered from the affected birds. These findings indicate that adult and 30- to 45-day-old psittacine birds will seroconvert following vaccination with β-propiolactone-treated pbfd virus. Also, hens inoculated with β-propiolactone-treated pbfd virus produce chicks that are, at least temporarily, resistant to virus challenge.

Adenovirus precipitating antibodies in the sera of brush-tailed possums in New Zealand

Sera collected from the Australian brush-tailed possum Trichosurus vulpecula in New Zealand in 1975 and 1989 were tested for the presence of antibodies to adenovirus. Of the 231 sera tested in an agar gel diffusion test, eight (3.5%) had precipitating antibodies to the group specific antigen of mammalian adenoviruses. Available data allowed 99/231 sera to be classified as being obtained from either adult (total 62) or sexually immature (total 37) possums. From the adult animals, 4/62 (6.5%) sera were positive, while no reactive sera were detected among the 37 immature animals. The results provide evidence that natural infection by an adenovirus occurs in possums in New Zealand. Further work needs to be carried out to isolate this adenovirus to enable detailed serological and epidemiological studies to be performed. A species-specific possum adenovirus could have potential in the biological control of this species.

Première relation d’un foyer de bursite infectieuse (maladie de Gumboro) dans l’Etat d’Anambra au Nigeria

Infectious bursal disease was reported in a flock of 7-week old vaccinated chickens. Clinical findings and post-mortem changes were classical as well as the microscopic pathology of the bursa. Bursal homogenates from dead birds were positive for IBD virus antigen in agar gel diffusion test (AGDT). Convalescent sera obtained from birds 14 days following the onset of clinical signs were also positive for IBD virus antibody in AGDT. Seven-week old susceptible birds, each infected i/m with 0.1 ml of a bursal preparation from the outbreak, showed clinical signs of IBD on the 3rd day and were all dead by the 6th day. Their bursae were also positive for IBD virus antigen in AGDT. This is the first recorded outbreak of IBD in Southern Nigeria following inoculation with a locally produced vaccine.

Mycoplasmas and acholeplasmas isolated from ducks and their possible association with pasteurellas.

Two hundred and sixty-three cases of clinically diseased ducks of all ages were examined for the presence of mycoplasmas. Mycoplasmas and acholeplasmas belonging to more than eight serogroups were cultured from 68 of them, and comprised 12 M anatis, one M columbinasale, two M gallinaceum, two M gallinarum, nine M synoviae, three unidentified Mycoplasma species, 37 Acholeplasma laidlawii and one unclassified acholeplasma belonging to each of serogroups 7 and 8. They were identified by biochemical characterisation, disc growth inhibition and agar gel diffusion tests. Fifty-three (78 per cent) of the isolates occurred with species of Pasteurella: 33.8 per cent with Pasteurella anatipestifer, 32.4 per cent with P multocida and 11.8 per cent with both P anatipestifer and P multocida. Nine of the isolates (13.2 per cent) were in pure culture and six (8.8 per cent) with other agents. Of the ducks negative for mycoplasmas 33.3 per cent were infected with P anatipestifer, 25.1 per cent with P multocida and 14.4 per cent with both P anatipestifer and P multocida. There was no correlation between the infections with mycoplasmas and P anatipestifer but there was a weak association between the infections with mycoplasmas, especially M anatis and P multocida.

RINDERPEST IN CATTLE IN MOSUL AREA: CLINICAL OBSERVATIONS AND SEROLOGICAL DIAGNOSIS

Outbreaks of rinderpest in cattle occurred in Mosul area between February to June 1987. The morbidity and mortality rates were 45.9% and 19.3%, respectively. The disease was characterized by pyrexia, nasal discharge, lacrimation, hyperemic mucous membranes, anorexia, diarrhoea, lesions in the buccal cavity, respiratory distress and reduced rumen motility. Haematological studies revealed leukopenia and concurrent infection with theileriosis and anaplasmosis in 26.6% of RP affected cattle. Rinderpest viral antigens were detected in mesentric and visceral lymphnodes and spleen of the affected animals by agar gel diffusion test

Serological reactions in sheep and cattle experimentally infected with three Australian isolates of bluetongue virus

Serums from 103 sheep and 24 cattle experimentally infected with one of 3 serotypes of bluetongue virus isolated in Australia were tested for antibody to bluetongue virus in the serum neutralisation test and the agar gel diffusion precipitin test. Antibody to bluetongue virus was first detected by these tests 8 to 10 days after intravenous infection in 4 sheep that were bled daily for serum analysis. The agar gel diffusion test failed to detect antibody in 28% (29/103) of sheep which had seroconverted in the serum neutralisation test. A further 7% (7/103) of sheep serums were negative in both tests 14 to 22 d after infection. Both tests detected antibody to bluetongue virus in all cattle serums by 10 days after detection of viraemia. In comparison with the intravenous route of infection, extended prepatent periods for the commencement of viraemia resulting from intradermal, subcutaneous and intrauterine routes of infection in the cattle caused corresponding delays in the detection of antibody. For example, one cow that was infected by intrauterine inoculation did not become viraemic until 22 d after inoculation and antibody was not detected until 32 d after inoculation.

<I>Actinomyces pyogenes</I>が分離された乳用牛の流産

Four cases of abortion occurred consecutively on a dairy farm in Hiroshima Prefecture from January to May, 1988. An aborted fetus and dam's fresh lochia of the last case were examined bacteriologically and serologically as a diagnostic service. Actinomyces pyogenes was isolated purely from the lungs, brain, spinal cord, thoracic fluid, contents of digestive organs, and lochia, and it was presumed to be the causative agent in this abortion. However, the aborted fetus could not be examined histopathologically due to severe autolysis. A serological survey on A. pyogenes infection was carried out on four aborted dams and raising cows at this farm, using the agargel diffusion test for protease antibodies against A. pyogenes. The antibody was demonstrated in high titer as 1: 64 in the serum of he dam that was aborted in May, and it was increased to 1: 128 after one month. Twenty-two out of 30 cows on the same farm were revealed to be positive reacters by this test, and nine cows including the three other aborted dam had levels of A. pyogenes protease antibody titers of >8 in ser

An agar gel diffusion test for differentiating between strains of type 1 IBD virus.

An agar gel diffusion test for differentiating between strains of type 1 IBD virus.

Occurrence of Southern Bean Mosaic Virus on Cowpea in Senegal

AbstractFor identification of cowpea viruses existing in Senegal, 180 samples collected from 4 different locations were examined. Initially agar gel diffusion tests were employed to identify the viruses present in these samples using antisera to 3 beetle‐transmitted viruses viz. CPMV, SBMV and CMeV. The results indicated the presence of SBMV in 78 samples mostly from Casamance while none of these viruses were detected in the samples collected from northern Senegal. These results were later confirmed by Enzyme‐linked Immunosorbent Assay (ELISA). This is the first report of occurrence of SBMV in Senegal.

Diagnosis of Rhodococcus equi infection in foals by the agar gel diffusion test with protein antigen

A protein antigen that reacted in the agar gel diffusion (AGD) test and which had equi factor(s) activity, was partially purified from the culture supernatant of Rhodococcus equi by successive column chromatography on diethylaminoethyl cellulose and Sepharose 4B. Employing a standard foal serum, the concentration of this antigen was adjusted for the AGD test. Optimal dilutions of the antigen reacted in the AGD test with sera from foals naturally infected with serologically different R. equi. The antigen prepared was considered suitable for use in field surveys of R. equi infection Accordingly, four groups of sera were tested: those from 18 foals diagnosed as being infected with R. equi, those from 54 control foals with culture-negative R. equi pneumonia, arthritis or cellulitis, those from 46 diseased foals suspected of having R. equi infection and those from 51 clinically normal foals. A positive precipitation reaction was observed with sera from 100% of the first group, 69.5% of the third group and 17.7% of the fourth group. A negative reaction was obtained with sera from 100% of the second group.

Isolation and characterization of Actinobacillus seminis strains from ovine semen samples and epididymitis.

SummaryEighteen strains of Actinobacillus seminis isolated from ovine semen samples and epididymitis were characterized according to their cultural and biochemical behaviour. The semen samples were collected from young, unmated and mature breeding rams suffering from epididymitis or subclinical genital infection.All A. seminis strains were non‐motile, non spore‐forming, uncapsulated, Gram‐negative pleomorphic rods, approximately 1–8 μm × 0.8‐1 μm. On bovine blood agar they formed low convex, greyish‐white, non‐adherent and non‐haemolytic colonies, which grew under aerobic conditions, but more luxuriantly when cultures were incubated in an atmosphere containing 10% CO2 at 37°C.All strains were catalase, oxidase, nitrate and ornithine decarboxylase positive, but indole, urease, phosphatase and beta‐galactosidase (ONPG) negative. They were fermentative in the O/F test and usually produced acid within 1 to 3 days from glucose, arabinose, fructose, maltose and xylose, but not from lactose, mannose and sucrose.In the agar gel diffusion test, antigenic differences were demonstrated among the isolates. On the basis of the cultural, morphological and biochemical characteristics, A. seminis can be differentiated from other Gram‐negative bacteria (e.g. Brucella ovis, Histophilus ovis etc.) involved in genital infections in rams.

Serological specificity of Pseudomonas glumae, the pathogenic bacterium of grain rot disease of rice.

Serological specificity of Pseudomonas glumae, the pathogenic bacterium of grain rot disease of rice, was tested by means of the agglutination and agar gel diffusion methods using rabbit antisera prepared by injecting living whole cell suspension of Ps. glumae strains, Ku8101, N7505 and N7501. In agglutination method, the antisera were not completely specific to Ps. glumae but their titers obtained with the bacteria other than Ps. glumae were extremely low. Agar gel diffusion test indicated that serological specificity of Ps. glumae depended upon the kind of antisera used, viz., anti-N7501-serum prepared with living whole cells of the strain N7501 was completely specific for Ps. glumae producing no precipitin band with any bacteria other than Ps. glumae. The other two antisera also produced specific band with Ps. glumae strains, suggesting the existence of some antibodies specific to Ps. glumae in these antisera, but they also produced faint precipitin bands with many pseudomonads. When antigens heated at 100C for 1hr were used, all of the three antisera showed almost complete specificity to Ps. glumae in agar gel diffusion test.

<I>Staphylococcus hyicus</I>subsp.<I>hyicus</I>による新生豚の化膿性関節炎および死産の発生

Staphylococcus hyicussubsp. hyicus was isolated in pure culture from the joints of two newborn piglets with arthritis and the lung and the stomach of a stillbirth in Torrori Prefecture during October, 1982 to January, 1983.Arthritis broke out in piglets 2 or 3 days old of the same litter on two farms. Stillbirth occurred in a sow on another farm.On these farms, S. hyicuswas also isolated from 17 of 21 swabs collected from the skin of dams.In the cross agglutination test, three strains ofS. hyicusisolated from the three farms showed a remarkable cross reaction with one another, but a one-sided reaction to the reference strain of ATCC 11249. On the contrary, all the 23 strains isolated from these farms and the reference strain produced an identical precipitation line in the agar gel diffusion test.

Ancylostoma ceylanicum (Looss, 1911) in golden hamsters (Mesocricetus auratus): pathogenicity and humoral immune response to a primary infection.

The response of hamsters to Ancylostoma ceylanicum was studied between days 13 and 200 after infection. The infected hamsters showed signs of anaemia, particularly between the 13th and 60th days. A significant loss in body-weight in the infected animals was also observed during this period. Serological studies with agar gel-diffusion, counterimmunoelectrophoresis and indirect haemagglutination tests revealed positive reactions between the 20th and 60th days followed by a negative response in the latent period between the 60th and 200th days of infection, counterimmunoelectrophoresis test remained positive for a period of 150 days in this experimental model.

Detection of influenza antibody in animal sera from Kassala region, Sudan, by agar gel diffusion test.

Detection of influenza antibody in animal sera from Kassala region, Sudan, by agar gel diffusion test.

Production of leukocidin by clinical isolates of Pseudomonas aeruginosa and antileukocidin antibody from sera of patients with diffuse panbronchiolitis.

The ratio of leukocidin-producing strains to clinical isolates of Pseudomonas aeruginosa was investigated together with the production of protease, elastase, and exotoxin A. We also examined whether these strains contain the common antigen which resides in the cell wall. By using the agar gel diffusion test with specific antisera, we found that 87 of 90 (96.7%) of clinical isolates produced leukocidin. Protease, elastase, and exotoxin A were also produced at high percentages. The common antigen was found to exist in all strains. Next, to estimate antileukocidin antibody in the sera of patients, we used an enzyme-linked immunosorbent assay with horseradish peroxidase-protein A. The sera of 39 patients with diffuse panbronchiolitis (DPB) were investigated for antileukocidin antibody. The mean antileukocidin titer in the sera of 17 DPB patients who were not infected with P. aeruginosa and 5 DPB patients who were transiently infected with the bacteria was about the same as the mean antileukocidin titer in the sera of 11 healthy controls, whereas the mean antileukocidin titer in the sera of 17 DPB patients who were persistently colonized was significantly higher than that in healthy controls. These results indicate that leukocidin was produced at the local site of infection in DPB patients.

Purification and Characterization of a Jordanian Isolate of Watermelon Mosaic Virus

AbstractThe Jordanian isolate of watermelon mosaic virus‐2 (WMV‐2Jo) was purified from infected Cucurbita pepo cv. Top Capi by extraction in 0.05 M sodium citrate buffer containing 0.01 M sodium diethyl dithiocarbamate and 0.01 M cysteine hydrochloride (0.01 M D + C), clarification with chloroform and n‐butanol, sedimentation by ultracentrifugation, and rate‐zonal centrifugation in 10–40% sucrose gradient. The purified virus had an ultraviolet absorption spectrum typical of a nucleoprotein with a low nucleic acid content. Homologous antiserum had a titre of 1: 256, as determined by the ring interface test. Electron microscopy of negatively stained purified virus revealed flexuous particles with a normal length of 750 nm. Cytoplasmic spindle‐shaped inclusions were readily detectable in infected epidermal cells under the light microscope. Thin sections of infected tissue revealed the presence of laminated aggregates, pinwheel and scroll inclusions. The virus reacted with antisera prepared to the Florida strain of WMV‐2 and zucchini yellow mosaic virus in a sodium dodecyl sulfate (SDS) agar gel diffusion test. Using the Derrick‐decoration combined technique of immune electron microscopy, the virus reacted strongly with the homologous antiserum and zucchini yellow mosaic virus antiserum, but less with antiserum prepared to the Florida strain of WMV‐2.

Studies on strains of Pasteurella haemolytica not typable by the indirect haemagglutination test

Thirty strains of Pasteurella haemolytica which were untypable by the indirect haemagglutination (IHA) test were examined serologically by rapid plate agglutination (RPA), agar gel diffusion (AGD), crossed immunoelectrophoresis (CIE) and counter current immunoelectrophoresis (CCIE) tests. Nine serogroups were identified by CCIE. Serogroup specificity, dependent on two antigens, was present in heated saline extracts of cells. Single representative strains from two serogroups were not pathogenic for specific pathogen-free lambs.

Specificity controls on commercial serologic reagents for meat speciation by agar gel diffusion tests.

Specificity controls on commercial serologic reagents for meat speciation by agar gel diffusion tests.

Untersuchungen zur Erfassung des latenten Befallsstadiums von Corynebacterium sepedonicum (Spieck. et Kotth.) Skapt. et Burkh. im Kartoffelgewebe

The causal agent of potato ring rot, Corynebacterium sepedonicum (Spieck. et Kotth.) Skapt. et Burkh., is well-known for its long incubation period. Often its inoculum concentration in the tissue of the host does not reach to induce distinct symptoms. Thus, during some years it can be distributed in potato material without to be detected. To inhibit the import and the seeding of potato tubers latently infected, special methods of detecting are necessary. In this paper, a sensitive technique for indicating the causal agent is proposed. It is suitable for analysing sprouts and tubers on potato ring rot. The material under test must be crushed and thereafter inoculated in young egg plant (Solanum melongena L.) for enrichment of the causal agent. Simultaneously, the samples homogenized are to analyse microscopically (Gram staining) and serologically (agargel-diffusion test from Ouchteelony). By suitable varieties of eggplant, for example “Frühviolette” and “Black Beauty”, very low cell concentration (less than 10 cells/ml) in plant tissue can be indicated. Following this test on latent infestation by C. sepedonicum, it is possible to use the tubers for further plant breeding studies. Der Erreger der Bakterienringfäule der Kartoffel, Corynebacterium sepedonicum (Spieck. et Kotth.) Skapt. et Burkh., ist für seine lange Inkubationszeit bekannt. Oft reicht seine Konzentration im Wirtsgewebe nicht aus, um eindeutige Symptome hervorzurufen. Dadurch kann er sich über Jahre hinaus unerkannt im Kartoffelanbau verbreiten. Um unter diesen Umständen einer möglichen Einschleppung vorzubeugen, sind spezifische Nachweismethoden notwendig. Es wird deshalb eine sehr empfindliche und sichere Nachweismethode für den Erreger vorgeschlagen. Sie ist sowohl für eine Kraut- als auch Knollenanalyse anwendbar. Für diesen Zweck werden die gezogenen Proben aufbereitet und über Testpflanzen (Solanum melongena L.) angereichert. Parallel hierzu erfolgt eine mikroskopisch-zytologische (Gram-Färbung) und serologische (Doppeldiffusions-Test nach Ouchterlony) Analyse. Mit geeigneten Eierfruchtsorten (z. B. „Frühviolette“, "Black Beauty") lassen sich sehr geringe Keimdichten (unter 10 Keime pro ml) im Pflanzengewebe nachweisen. Die mit Hilfe dieses Testes auf ihre latente Verseuchung mit C. sepedonicum untersuchten Knollen können anschließend züchterisch weiterverwendet werden.