Indirect Hemagglutination Test for Chlamydial Antibodies

An indirect hemagglutination (IHA) test is described for chlamydial antibodies in psittacosis diagnostic sera; for this test tanned sheep erythrocytes sensitized with a deoxycholate extract of Chlamydia psittaci grown in Vero cell monolayers were used. Adaptation of the IHA test to the Microtiter system decreased sensitivity; nevertheless, the Microtiter-IHA test was more sensitive than the complement fixation test. Lymphogranuloma venereum antibodies also were detected by using antigen extracted from C. psittaci.     

Microtiter Plate Agglutination Test for Salmonella Antibodies

Similar results were obtained when testing human sera for Salmonella antibodies by the tube agglutination test and by the Microtiter plate agglutination test. The plate test was easier to perform and saved time, space, antigen, and serum.     

Passive Hemagglutination Assays for the Detection of Antibodies to Herpes Viruses

A simple and effective method for the detection of antibodies to herpes simplex virus (HSV), human cytomegalovirus (HCMV) and varicella-zoster virus (VZV), has been established using the passive hemagglutination assay (PHA) in combination with viral specific glycoproteins. The results obtained with the PHA were compared with those from neutralization (NT) and complement fixation (CF) tests. The PHA test for each of the herpes viruses appears to compare favorably with the other assays tested. The specificity and sensitivity of HSV PHA to NT were 100%, whereas the specificity and sensitivity of HSV CF test to NT were 98% and 100%, respectively. For HCMV, the specificity and sensitivity of PHA to NT and PHA to CF were 100%. Similarly, the specificity and sensitivity of VZV PHA to NT were 100%. Because of the low sensitivity of the VZV CF, the sensitivity of CF to NT was 83%. Furthermore, the range of antibody titers and their absolute levels obtained in the PHAs were significantly greater than those in the NT and CF tests.     

Passive Hemagglutination-Inhibition Test for Typing Foot-and-Mouth Disease Virus

In addition to currently used serological tests for the occurrence of foot-and-mouth disease virus (FMDV), a specific "passive" hemagglutination-inhibition (HAI) test has been developed as a supplement. Serial twofold dilutions of antiserum (0.05 ml) were mixed with 0.05 ml of a constant concentration of FMDV. After incubating for 30 min at 37 C, agglutinating antibodies were determined by adding 0.1 ml of 2.5% virus-sensitized erythrocytes. The minimum concentration of antiserum required to agglutinate the erythrocytes defined the inhibition in the HAI test. Similar tests using different concentrations of virus to inhibit antibodies were carried out in parallel fashion. The relationship between the logarithm of the HAI titer and the concentration of inhibiting virus was nearly first order (P > 0.25). The slope was used as a measure of the relative specificities of the antigen-antibody interaction and was independent of concentration. The HAI test was type-, subtype-, strain-, and variant-specific with the viral antigens used. In particular, typing was performed directly on bovine antisera.     

Microtiter Plate Agglutination Test for Brucella canis Antibodies

A micro-agglutination test for the antibodies to Brucella canis produced similar results to those obtained with the standard tube agglutination method in human and canine sera. The micromethod does provide an economical means of screening sera for the presence of antibodies.     

Haemagglutination durch Pockenvirus

Zusammenfassung Auf 56°C. erwärmtes Vaccinevirus erzeugt beim Meerschweinchen Antihaemagglutinine, die nur wenig schwächer sind, als die durch lebendes Virus erzeugte. Erwärmen auf 63°C. und selbst auf 100°C. schwächt wohl die immunisierende Fähigkeit, hebt sie aber keineswegs völlig auf. Auch Behandlung mit Phenol oder Formaldehyd (5 Tage bei 4°C.) wirkt nur abschwächend.     

Serological Activity of Protein A of Staphylococcus aureus: the Precipitinogen as an Antigen for Determining Antibodies by the Passive Hemagglutination Test

Tanned sheep erythrocytes have been considered incapable of sensitization with the precipitinogen of protein A of Staphylococcus aureus, so that the activity of this antigen in serological reactions has so far been studied by means of the agar diffusion test (ADT) only. The precipitinogen of the protein A in this study was found to become attached to the tanned erythrocytes and to sensitize them for the passive hemagglutination test (PHT). It was determined that, in contrast to nonspecific reactivity between normal human serum and the precipitinogen in the ADT, the reaction in the PHT was of specific nature. Of seven species studied, all normal human, dog, and hog sera tested were positive in the PHT. However, the hemagglutinin titers of the sera of the two animal species by far exceeded those of the human sera. The data emphasized the usefulness of the highly sensitive PHT for assaying antibodies to protein A.     

Haemagglutination durch Pockenvirus

Zusammenfassung In dem Lungenextrakt verschiedener Tierspecies findet sich ein Stoff, der die Vaccine-Haemagglutination hemmt. Dieses Inhibin ist thermolabil und wird bei 56° oder 63° C. nach 30 Minuten zerstört. In der Lunge des Menschen findet sich daneben noch ein thermostabiler Stoff, der im Eisschrank schnell verschwindet.Durch Immunisierung mit Lungenextrakt lässt sich vom Kaninchen Antiserum gegen die Inhibine nicht nur aus Mäuselunge, sondern auch gegen solche aus Lungen anderer Tierarten gewinnen.Es wird die Bedeutung dieser die Haemagglutination hemmenden Stoffe als Virus-Acceptoren besprochen, die jedenfalls für das Zustandekommen der Infektion von Bedeutung sind.Mitteilung 5: Antonie van Leeuwenhoek15, 53, 1949.     

Haemagglutination of Bacteroides fragilis

Abstract The relationship between the ability to cause haemagglutination (HA) and the presence of capsules and/or pili was examined for 50 clinical isolates of Bacteroides fragilis . HA was tested using a slide technique, and bovine, porcine, guinea pig, rat, rabbit, horse, human, chicken and pigeon erythrocytes. Chicken and pigeon erythrocytes were the best indicators for HA with 43 (86%) of the strains tested causing HA and 39 (78%) with strong reactions. Capsule staining showed that the same 43 strains causing HA also produced a demonstrable capsule. No pili were found on either encapsulated or non-encapsulated strains using transmission electron microscopy. These results suggest that adherence of B. fragilis is related to the presence of capsular material, not pili.     

Indirect Hemagglutination Test for Detection of Antibodies to Cytomegalovirus

An indirect hemagglutination test has been adapted for use with cytomegalovirus. The test is highly sensitive and reproducible. Both immunoglobulin M and immunoglobulin G antibodies can be detected by this method. The hemagglutination reaction can be inhibited by small amounts of homologous antigen. This principle permits early identification of virus isolated from diagnostic specimens.     

Microtiter Hemagglutination-Inhibition Test for the Detection of Encephalomyocarditis Virus Antibodies

Several variables were found to affect the agglutination of sheep erythrocytes by encephalomyocarditis virus. A satisfactory and reliable microtiter hemagglutination-inhibition test is described.     

Plate Hemolysin Test for the Rapid Screening of Toxoplasma Antibodies

A plate hemolysin test was developed to screen serum specimens for the presence of toxoplasma antibodies. When we tested 130 sera by both this test and the standard toxoplasma dye test, we found the plate hemolysin test to be a rapid, sensitive, and economical method for detecting toxoplasma antibodies. In all but one instance it paralleled the dye test. A comparison of the results of testing six sera by the hemolysin, hemagglutination, and dye-test techniques suggested that the hemolytic antibodies were more closely related to hemagglutinating antibodies than to dye-test antibodies. We could not store sheep erythrocytes sensitized with toxoplasma lysate for more than 3 days without altering the sensitivity of the test. Concanavalin A proved to be an effective coupling agent for binding toxoplasma antigens to red-cell membranes, a quality attributed to its affinity for specific polysaccharide-combining sites.