Slide Flocculation Test Research Articles

A re-evaluation of the slide flocculation test for the diagnosis of schistosomiasis with adult worms as antigen.

The present study was conducted to determine whether extracts from adult Schistosoma mansoni could be coated onto cholesterol-lecithin crystals. Of particular interest was the use of stunted schistosomes (SS) recovered from rabbits. The reactions obtained with this antigen in this slide flocculation (SF) test were compared with those employing antigens from cercariae and mature adult worms. The stunted schistosome SF test (SFSS) showed a high sensitivity and specificity while cercarial antigen showed extensive cross reaction with Trichinella spiralis, Ascaris lumbricoides, and Echinococcus granulosus antisera. Both SS and cercarial antigens reacted with syphilitic sera, but the former only with high titer sera. The antigen from mature adult worms could not be coated onto cholesterol crystals, a finding which is in agreement with previous investigations. The relative simplicity of the SFSS test and its apparent high sensitivity and specificity indicates that the test may be an ideal epidemiological tool for schistosomiasis surveys. The results obtained should encourage additional study of the procedure involved and investigation into the role of lipids in flocculation tests. In addition, the findings should stimulate immunological studies of the stunted schistosomes.

Potato Virus M Found in Japan

A virus was isolated from apparently healthy plants of potato varieties, USDA seedling 41956 and Kintoki-imo. The virus was transmitted by sap, but not by aphids so far as the present study concerned. By sap inoculation, it produced ring-like local lesions on the inoculated leaves of Nicotiana debneyi, while it caused systemic infection without symptoms in tomato and egg plant. Other plants such as Solanum demissum, S. villosum, Chenopodium amaranticolor, C. capitatum, C. murale, and Gomphrena globosa were also susceptible to the virus. Several potato varieties also became infected systemically.The virus was inactivated in 10 minutes between 65 and 70°C, and between 2 and 3 days, at room temperature (ca. 20°C). Dilution end point was shown to lie between 1:5, 000 and 1:10, 000. In electron microscopy using direct negative staining method devised by Doi et al. (1965), elongated particles of about 650mμ were observed. The virus was identified with potato virus M (PVM), because of its similarity to the description of PVM by Bagnall et al. (1956) in host range, mode of transmission, symptomatology, physical properties, and particle morphology. Antisera against PVM and PVS (potato virus S) were prepared by intravenous injections of rabbits with partially purified virus preparations. The antiserum against PVM was shown to have a homologous titre of 1:256 in precipitation test, and to be applicable to slide flocculation test. Result of cross precipitation tests between PVM-antiserum and PVS, and vice versa, showed some serological relationship between PVM and PVS. In the potato varieties Norin No.1, Oojiro, and Kennebec, mild to severe symptoms were observed on field-grown plants, naturally infected with PVM. The characteristic symptoms associated with PVM were of veinal streak, glossy appearance of leaf surface, crinkling, and downward curling of leaflets. Percentages of infection by PVM in seed potatoes maintained by the Tsumagoi National Potato Foundation Seed Farm were 11% in Norin No.1, 50% in Oojiro, 14% in Kennebec, 31% in Danshaku-imo, and almost 100% in Saco, USDA seedling 41956, and Kintoki-imo variety, respectively. With an exception of Norin No.1, these varieties were often symptomless carriers of PVM under field conditions.

Tobacco Ringspot Virus Isolated from Crotalaria (Crotalaria spectabilis).

Two causal viruses were isolated from crotalaria (Crotalaria spectabilis) showing yellow ringspot and mosaic symptoms. The first virus was identified with bean yellow mosaic virus. The virus was transmitted mechanically and also by Myzus persicae. The hosts of this virus were crotalaria, broad bean, bean, soybean and Chenopodium amaranticolor. In electron microscopy using dip method, long flexuous thread-like particles were observed, and the length of them was 700-800mμ. Juice from diseased broad bean leaves reacted positively with antiserum of bean yellow mosaic virus (Komuro and Tochihara, 1964) in a slide flocculation test. The second virus was identified with tobacco ringspot virus. The virus was transmitted mechanically and also by Myzus persicae. The host range of this virus was comparatively wide, namely, aster, zinnia, Nicotiana tabacum (Bright Yellow, Xanthi), N. glutinosa, petunia, okra, broad bean, crotalaria, bean, soybean, turnip, New Zealand spinach, Gomphrena globosa, C. amaranticolor, beet and others. Characteristic ring-like pattern symptoms were observed on N. tabacum (Bright Yellow, Xanthi), N. glutinosa, and Datura stramonium, and these symptoms had a tendency to be masked under high temperature conditions. This virus isolate showed some differences from the hitherto reported tabacco ringspot viruses in noninfectivity to cucurbitaceous plants and in the symptoms on soybean. In electron microscopy using direct negative stain methond, spherical particles of about 26mμ in diameter was observed. The virus in vitro withstood heating at 65°C for 10 minutes, dilution to 5, 000 and 7 day's aging at room temperature.Kahn et al. (1963) reported that bean yellow mosaic virus was isolated from crotalaria, but the disease of crotalaria by tobacco ringspot virus has not yet been reported. This is also the first report in recognition of tobacco ringspot virus in Japan.

Schistosomiasis Mansoni in the Chimpanzee: Parasitologic, Clinical, Serologic, Pathologic and Radiologic Observations *

Summary Studies conducted in splenectomized and intact chimpanzees (Pan satyrus) indicated that this primate is susceptible to experimental infections with Schistosoma mansoni. After a prepatent period of six to seven weeks, viable eggs appeared in the stools. The pattern of egg production remained relatively constant and sustained for the duration of the experiment. At necropsy, active and well-developed adult schistosomes were found in the distal branches of the mesenteries. Although most of the eggs were recovered in the large intestine and in the liver, viable eggs were also found in the lungs, the pancreas, the kidneys, the small intestine, the urinary bladder and the spleen. In the heavily infected chimpanzees, there was an elevation in temperature between the sixth and ninth week after exposure, anoxia, diarrhea with mucus and frank hemorrhage, and a transient marked decrease in activity and responsiveness. These symptoms were followed approximately three weeks later by transient hepatomegaly and ascites. A lymphocytic leukocytosis accompanied the first appearance of eggs in the feces and the onset of clinical symptoms. Pathologic and radiologic observations revealed changes resembling human pipestem fibrosis in a heavily infected animal, and portocaval anastomoses around the lower esophagus and diaphragm. Most of the eggs in the gut were in the mucosal layer. The course of antibody production as measured by the slide flocculation test using as antigens somatic extracts of eggs and cercariae and metabolic products of adult worms followed a pattern similar to that observed previously in mice, rabbits, monkeys and humans. Cutaneous reactivity was successfully transferred from an infected chimpanzee and from infected humans to uninfected rhesus monkeys. Reagenic antibodies, which were largely destroyed by heating the serum, were demonstrated approximately three months after exposure and persisted throughout the duration of the experiment. To the authors' knowledge this is the first time that antischistosome reagenic antibodies have been detected in humans and chimpanzees and successfully transferred to rhesus monkeys. The pattern of egg output in the feces, the distribution of eggs in various organs, the clinical course, the pathological effects and the serological response of schistosomiasis in chimpanzees followed a course similar to that which had been observed in men.

COMPARATIVE STUDIES OF SOME IMMUNOLOGIC SCREENING TESTS FOR SCHISTOSOMIASIS IN ETHIOPIA.

Abstract : A comparative study of various immunodiagnostic screening tests for schistosomiasis was conducted in 100 inhabitants of an Ethopian village located in an area highly endemic for schistosomiasis (Schistosoma mansoni). Infection of schistosomiasis was measured by applying the following independently performed test to each individual included in the study: (a) a complement-fixation test; (b) a slide flocculation test; (c) a card test for the rapid diagnosis of schistosomiasis; (d) a fluorescent antibody test; (e) a serologic test using the secretions and excretions of cercariae of S. mansoni as the antigens; (f) a skin test; and (g) stool examinations by the direct and merthiolateiodine formalin (MIF)-ether concentration technique. The results of each of these immunodiagnostic tests were compared with those of the stool examinations. (Author)

Cross absorption studies performed with Schistosoma mansoni and Trichinella spiralis antigens in sera from patients with trichinosis

The apparent one-way cross reaction between Schistosoma mansoni antigens and sera from patients with trichinosis was studied by absorption technics. When the Trichinella antiserum was absorbed with Trichinella slide flocculation test antigen, the homologous antibody was removed but the antibody reactive against cercarial slide flocculation test antigen remained. The converse was also true in that absorption of the Trichinella antiserum with schistosome antigen removed antibody serologically reactive with the schistosome antigen but failed to remove antibody reactive with Trichinella antigen.

Cholesterol-Lecithin Slide (TsSF) and Charcoal Card (TsCC) Flocculation Tests Using an Acid Soluble Fraction of Trichinella spiralis Larvae

Two simple sensitive flocculation tests were developed employing acid soluble T. spiralis larvae antigen absorbed onto cholesterol-lecithin crystals. Washing of the emulsion greatly increased the sensitivity of the antigen in the slide flocculation test. The addition of charcoal to the antigen emulsion permitted its use in a simple card test using serum or minute amounts of plasma collected from finger puncture. Absorption of reactive sera with a single dose of washed, packed, and essentially dry antigen-cholesterol-lecithin complex resulted in a complete removal of serologically detectable antibody indicating that the tests were based upon a true antigen-antibody system. Sensitivity of both tests was excellent. In the slide flocculation test, 64 sera from 68 patients were reactive, 2 were weakly reactive and 2 were nonreactive. All 21 sera from trichinosis patients were reactive in the charcoal card test. The tests also appear to be relatively specific. Only 3 sera from a total of 96 normal persons and patients with other diseases were reactive in the slide flocculation test; 13 sera showed weak reactions. With the charcoal card test 3 reactions were obtained with sera from a total of 64 normal individuals and patients with other diseases. The tests are especially well suited to small laboratory and field conditions because they are simple to perform and utilize antigenic emulsions which may be kept for prolonged periods without apparent loss of reactivity. Slide flocculation tests are among the simplest procedures for the serodiagnosis of infections. These techniques have not yet found wide application in the field of parasitology primarily because of the difficulty in many instances of combining the parasitic antigens with the carrier (cholesterol, latex, or bentonite). Suessenguth and Kline (1944) found that an aqueous extract of Trichinella larvae coated onto cholesterol crystals could be used as antigen in a simple and rapid flocculation slide test for trichinosis. They reported that this test was more sensitive than the complement fixation test (Suessenguth et al., 1957). However, other investigators have presented evidence indicating that this test lacks the specificity of other serological tests for trichinosis (Bozicevich et al., 1951; Sadun and Norman, 1955a; Greene and Brazeale, 1951). Recently Anderson (1960) developed a slide Received for publication 26 April 1963. flocculation test for schistosomiasis using antigen prepared by coating a buffered saline extract of cercariae onto cholesterol-lecithin particles and subsequently washing this complex to remove the excess antigen. This method has been shown to be one of the most sensitive and specific serodiagnostic procedures for schistosomiasis (Anderson, 1960; Anderson and Naimark, 1960; Jachowski and Anderson, 1961). Following the development of the rapid plasma reagin card test (Portnoy et al., 1962) for syphilis, the schistosome slide flocculation te t antigen was adapted to the card procedure and evaluated under laboratory and field conditions (Sadun et al., 1963). The card test in schistosomiasis gave results comparable to those obtained with the standard slide flocculation procedure and permitted the test to be completed within a few minutes on plasma obtained by finger puncture. The purpose of the current study was to determine whether similar procedures would provide a slide flocculation test for trichinosis

A FLOCCULATION TEST FOR SALMONELLA ANTIBODIES USING SENSITIZED BENTONITE PARTICLES

A rapid slide flocculation test using bentonite particles sensitized with salmonella O somatic antigen extracts has been described. A polyvalent antigen was also prepared using a number of salmonella O extracts thereby making the test useful for the screening of either a monovalent antibody or covering a wide range of O groups. The sensitized test antigen can be lyophilized and, when rehydrated, yields reproducible results. This investigation marks the first reported successful sensitization of bentonite with polysaccharide material. The practical application of this test is now undergoing investigation.

Relationship of antibody nitrogen to titer obtained in the cercarial antigen slide flocculation test for schistosomiasis

It was possible to absorb all of the serologically reactive antibody from schistosomiasis sera with a single calculated volume of washed, packed, and essentially dry cholesterollecithin crystals coated with cercarial antigen. Micro-Kjeldahl nitrogen determinations performed on the antigen complex and on absorbed antibody-antigen complexes were used to estimate the relationship of antibody nitrogen to titer. The relationship was found to be directly proportional, since a graph of mg N/ml of sera plotted on arithmetic ordinates against the titer formed a straight line. Approximately 2.1 μg of antibody nitrogen is required in the flocculation test to give a minimal positive reaction. A possible practical application of this work is the use of the determination for nitrogen content to standardize control sera for serologic surveys.

Serologic diagnosis of Schistosoma mansoni infections. II. Sensitivity of intradermal and serologic tests on individuals with an unequivocal diagnosis of schistosomiasis.

SummaryThe relative sensitivity of four intradermal and five serologic procedures was determined on patients with an unequivocal diagnosis of Schistosoma mansoni infection. Cercarial antigen proved to give the highest sensitivity (75%) of the intradermal antigens. At this laboratory, sensitivity of all intradermal tests was considerably less than that obtained with the serological procedures. Sensitivity of the complement fixation test was 97% with adult antigen and 96% with cercarial antigen. Comparable results were obtained in the cercarial slide flocculation (98%) and the cercarial agglutination (98%) tests. However, a relatively large number (21%) of weak reactions were obtained in the agglutination test. The circumoval precipitin procedure showed a sensitivity of 88%.All schistosome infections in the group of 355 patients, on whom all tests were performed, could have been detected serologically. A combination of either complement fixation test with the slide flocculation or agglutination test would have sufficed. In a like manner a combination of the slide flocculation procedure and the agglutination test would have detected all of the infections. The complement fixation tests and the slide flocculation test showed the greatest sensitivity.

Serologic diagnosis of Schistosoma mansoni infections. I. Development of a cercarial antigen slide flocculation test.

SummaryThe reaction of cercarial antigen-cholesterol-lecithin complex with schistosome antibody provides a simple sensitive slide flocculation test for schistosome infections.Capacity of the antigen emulsion to react with homologous antibody was greatly increased by removing the antigen-cholesterol-lecithin complex from the salt solution in which it was prepared and resuspending the complex in fresh salt solution.The S. mansoni cercarial antigen used in the test also reacted with sera from patients with S. japonicum and S. haematobium infections.While specificity of the test was excellent in other helminthic diseases, cross-reactions with the S. mansoni antigen and T. spiralis anti-sera did occur. This finding is consistent with those obtained from other tests using cercarial antigens.The excellent sensitivity (98%) and simplicity of the procedure make the test ideally suited for field and survey purposes.

Flocculation tests for tularemia.

Abstract 1.1. Methods of producing a cholesterol, lecithin, turlarensis extract antigen emulsion for a microscopic slide and macroscopic tube flocculation test have been described. 2.2. The sensitivity and specificity of the antigen emulsion could be adjusted to conform to the standard antigen emulsion. Method of standardizing the antigen emulsion is described. 3.3. The procedure of making a complete antigen and the method of making the antigen emulsion using the complete antigen is given. 4.4. Data are presented showing the antigen emulsion to be specific. 5.5. The flocculation tests are rapidly performed, the results are clear-cut, and easily read. The tests give reproducible results and the titers are higher than with the agglutination test.

Comparison of the Ide and Harris (VDRL) slide flocculation tests in Nigeria.

For over 10 years the Ide test has been in use in Nigeria as a simple slide flocculation test for syphilis and yaws in hospitals and clinics, and in the field, where the Kahn and Wassermann tests are impracticable. It was thought desirable that the results obtained by the Ide test should be compared with those obtained by the newly introduced Harris (VDRL) slide flocculation test, and an estimate made of the relative values of the two tests for use in the field. The sera of 8,077 Nigerian subjects were therefore tested in parallel by the Ide, Harris, and Kahn tests. The Kahn test was used as the basis on which the comparison should be made for two reasons:

Study of the TPI test in clinical syphilis.

In previous publications it has been reported that the Treponema pallidum immobilization (TPI) test may be expected to be reactive in untreated or treated late syphilis. * This study of seroreactivity in patients having untreated and treated late syphilis was undertaken to compare the sensitivity in late syphilis of the TPI test, as modified by Portnoy, Harris, and Olansky, with other serologic tests for syphilis, e. g., Kahn quantitative, Kolmer (cardiolipin) quantitative, and VDRL slide flocculation test quantitative. CLINICAL MATERIAL One hundred and twenty patients having untreated or treated late syphilis were selected from inpatients and outpatients attendant at the Delgado Outpatient Clinic, New Orleans; Board of Health venereal disease clinic, Chicago; Mayo Clinic, Rochester, Minn.; and Macon County Health Department, Tuskegee, Ala. In all patients, spinal fluid examinations had been performed at some time, and serologic tests for syphilis were performed at

A slide flocculation test for the diagnosis of contagious bovine pleuro-pneumonia.

A slide flocculation test for the diagnosis of contagious bovine pleuro-pneumonia.

A Reliable, Sensitive, Simple, and Rapid Slide Flocculation Test for Syphilis

A Reliable, Sensitive, Simple, and Rapid Slide Flocculation Test for Syphilis