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PubMed2000

Rapid detection of contagious caprine pleuropneumonia using a Mycoplasma capricolum subsp. capripneumoniae capsular polysaccharide-specific antigen detection latex agglutination test.

Latex microspheres (diameter, 8 microm) were coated with anti-Mycoplasma capricolum subsp. capripneumoniae polyclonal immunoglobulin G (IgG) antiserum (anti-F38 biotype). The coated microspheres, when used in a latex agglutination test (LAT), detected M. capricolum subsp. capripneumoniae antigen in the serum of goats with contagious caprine pleuropneumoniae (CCPP). Beads also agglutinated strongly in the presence of purified M. capricolum subsp. capripneumoniae capsular polysaccharide (CPS). Preabsorption of CPS-specific antibodies prior to coating of the beads removed agglutinating activity in the presence of M. capricolum subsp. capripneumoniae, strongly suggesting that CPS is the likely soluble antigen recognized by the test. In addition, the specificity of the LAT exactly mirrored that of an M. capricolum subsp. capripneumoniae CPS-specific monoclonal antibody (WM25): of the 8 other mycoplasma species tested, agglutination was observed only with bovine serogroup 7. The LAT detected all 11 strains of M. capricolum subsp. capripneumoniae examined in this study, with a sensitivity level of 2 ng of CPS, or the equivalent of 1.7 x 10(4) CFU, in a reaction volume of 0.03 ml of serum. With field sera from goats with CCPP, the results of the LAT exhibited a 67% correlation with the results of the currently used complement fixation test (CFT), with the main discrepancy in diagnosis resulting from the increased sensitivity of the LAT compared to that of CFT. This antigen-detection LAT should prove particularly useful in identifying animals in the earliest stages of CCPP and combines sensitivity and low cost with ease of application in the field, without the need for any specialist training or equipment.

Animals↗
PubMed1977

Rheumatoid factor: a cause of fals positive histoplasmin latex agglutination.

Ten of thirteen patients with positive histolatex agglutination titers of 1:32 or greater had no evidence of acute histoplasmosis. Three of these false positives had rheumatoid arthritis. A fourth had a rising mycoplasma complement fixation titer, and the fifth had a high titer of cold agglutinins. All of these are associated with abnormal immunoglobulin M production. To evaluate the role of rheumatoid factor in producing false positive histolatex agglutination, the histolatex test was performed on sera from 32 patients having rheumatoid factor at a titer of 1:40 or greater. Four of these sera agglutinated the histoplasmin-coated latex particles at titers of 1:32 or greater. Review of clinical records suggests the this reactivity is nonspecific. It is our purpose to call attention to rheumatoic factor as a cause of false positive histolatex agglutination.

False Positive Reactions↗
PubMed1990

Use of latex agglutination technique for detecting Legionella pneumophila (serogroup 1) antibodies.

Following the outbreak of Legionnaires' disease in Stafford in 1985, 500 serum samples were submitted to the indirect immunofluorescence antibody test and a latex agglutination. Latex agglutination using ultrasonically disrupted Legionella pneumophila antigens coupled to latex particles, proved a rapid, simple method for detecting circulating antibodies to L pneumophila in a one minute slide latex agglutination test. There was good correlation with the indirect immunofluorescence antibody test (IFAT), and the specificity and sensitivity with respect to a diagnostic result were 98.3% and 97.6%, respectively, using a series of well characterised sera. The latex agglutination test seems well suited as a screening test for presumptive cases of Legionnaires' disease; the latex reagent is easy to prepare and seems to remain stable at 4 degrees C for up to six months.

Antibodies, Bacterial↗
PubMed1987

A latex agglutination test for field diagnosis of contagious caprine pleuropneumonia.

Latex beads were sensitised with a polysaccharide isolated from a F38 culture supernatant and used in a slide agglutination test to detect serum antibodies in goats with contagious caprine pleuropneumonia. The latex agglutination test detected antibodies in the sera of goats by 22 +/- 2 (mean +/- 1 sd) days after contact exposure to contagious caprine pleuropneumonia, whereas the complement-fixation test detected antibodies by 24 +/- 4 days after contact exposure. Both tests were negative with 181 sera from a farm which was free of the disease. When the same tests were done on 763 sera from two different farms with outbreaks of classical contagious caprine pleuropneumonia, 63 per cent were positive by the latex agglutination test and 23 per cent were positive by the complement-fixation test. Besides being more sensitive than complement fixation, the latex agglutination test can be performed in the field using undiluted serum or whole blood and a result obtained within two minutes.

Animals↗
PubMed1995

Cell surface properties of Aspergillus fumigatus conidia: correlation between adherence, agglutination, and rearrangements of the cell wall.

Culture conditions that lead to swelling and germination dramatically influence cell surface characteristics and properties of Aspergillus fumigatus conidia. Conidial adherence to polystyrene and agglutination markedly increased during swelling, in a time-dependent manner. Agglutination appeared to be sensitive to cycloheximide and calcium. Removal of cell wall polysaccharides by lyticase or sodium metaperiodate suppressed agglutination of conidia. Proteinase K weakly decreased it whereas dithiothreitol strongly dispersed the cells. These observations suggest that both cell surface carbohydrates and proteins are involved in the agglutination process. Electron microscopic observations demonstrated that the cell wall of conidia was subject to some rearrangements during swelling, involving degradation and loss of the external convoluted layer, and subsequent exposure of underlying ligands. This was confirmed using lectins labelled with gold or fluorescein isothiocyanate, which showed that some carbohydrates, particularly those acting as ligands for peanut agglutinin, are largely exposed during the process. Finally, SDS-PAGE revealed major protein changes between resting and swollen conidia. We conclude that the ability of A. fumigatus conidia to aggregate correlates with an increase in adherence and biochemical reorganization of the cell wall.

Aspergillus fumigatus↗
PubMed1983

Rapid diagnosis of Legionnaires' disease by latex agglutination.

We developed a latex agglutination test to detect antigen(s) of serogroup 1 Legionella pneumophila in urine and evaluated its ability to diagnose legionnaires' disease. Antigen was detected in 46, or 70%, of 66 patients with serogroup 1 legionnaires' disease but in none of 51 patients with various bacteremic infections nor 60 with urinary tract infections. One of 50 patients with other pulmonary infections was antigen-positive, an immunosuppressed patient with Pneumocystis carinii infection. Seven other patients infected with P. carinii were negative. When compared with radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) using serial dilutions of a single antigen-containing urine, latex agglutination was 16-fold less sensitive. However, 82% of RIA- or ELISA-positive specimens were positive by latex agglutination. Latex agglutination is simpler and more rapid than ELISA or RIA, and it should prove valuable in situations where ELISA or RIA are unavailable or unaffordable.

Antigens, Bacterial↗
PubMed1985

Novel platelet-agglutinating protein from a thrombotic thrombocytopenic purpura plasma.

A novel platelet-agglutinating protein (PAP) was purified approximately 2,000-fold from the plasma of a patient with thrombotic thrombocytopenic purpura (TTP) by ammonium sulfate fractionation, DEAE-Sephacel and concanavalin A-Sepharose chromatographies. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with and without reduction, this preparation revealed a major protein band with a molecular weight of 37,000, and a minor band with a molecular weight of 32,000-34,000. After elution from the gel, only the 37,000-mol wt protein corresponding to the major band induced the platelet agglutination. When four normal plasmas and the recovery plasma from the same TTP patient were subjected to the similar purification steps, the 37,000-mol wt major band was absent. The 125I-PAP bound to the platelets in a concentration-dependent manner. The platelet agglutination induced by PAP was not inhibited by hirudin, heparin in the presence of antithrombin III, phenylmethylsulfonyl fluoride, apyrase, aspirin, or prostaglandin I2. However, it was inhibited by IgG from normal adults and from the same TTP patient after recovery. The anti-37,000-mol wt PAP antiserum prepared in the rabbit formed a single precipitin line against the highly purified PAP. Using this antiserum in the Western immunoblotting, the 37,000-mol wt protein band was found in the three TTP plasmas, of which the platelet-agglutinating activity was inhibited by the anti-37,000-mol wt PAP IgG. The 37,000-mol wt immunoprecipitin band was absent in the plasmas obtained from another two TTP patients, two normal subjects, two patients with idiopathic thrombocytopenic purpura, and two patients with disseminated intravascular coagulation. These results suggest that the 37,000-mol wt PAP is present only in certain cases of TTP, and is likely to be responsible for the formation of platelet thrombi in the microcirculation.

Adult↗
PubMed1982

Concanavalin-A-mediated thymocyte agglutination: a model for a quantitative study of cell adhesion.

This report describes a quantitative study of the agglutination of rat thymocytes with concanavalin A (ConA). The probability that two ConA-coated cells remain bound after centrifugation was determined over a wide range of lectin concentrations. The minimal force required to separate agglutinated cells and the number of ConA molecules bound per cell were measured in similar experimental conditions. Agglutinated cells were examined by electron microscopy to estimate the area of membrane involved in adhesion. The dependence of agglutination on cell metabolism was studied: cold (4 degrees C), sodium azide (15 mM) and cytochalasin B (10 micrograms/ml) inhibited thymocyte adhesion. The importance of lateral movements of ConA molecules was assayed by measuring the adhesion of ConA-coated glutaraldehyde-fixed thymocytes to untreated cells: substantial binding occurred, but at a reduced level relative to untreated cells. A mathematical analysis of experimental data allowed the following conclusions. (1) At least 10(3) ConA bonds were involved in cross-linking two bound cells, which required the lectin molecules to be concentrated in the binding area, at least when low ConA concentrations (0.5 microgram/ml or less) were used. (2) The dependence of the binding probability on lectin concentration was fairly linear when the latter was small, which implied that the limiting step in cell-cell adhesion was the formation of a bond between a single ConA molecule and a ligand on the other cell. (3) The mean intercellular-contact time for the formation of this first bond was about 10 S for high concentrations of ligand (8 micrograms/ml). It was possible to fit the above data into a physically consistent quantitative model of cell adhesion.

Animals↗
PubMed1986

A new latex agglutination test for rapid diagnosis of group A streptococci.

A rapid diagnostic test for group A streptococci from throat swabs (Culturette Brand 10-Min Strep ID test of Marion Inc.) was performed in 210 patients with acute pharyngitis. This agglutination test is based on the extraction of streptococcal polysaccharide by nitrous acid and observe agglutination with anti-polysaccharide-coated latex suspension. There was a 95.2% total agreement with a standard culture method and agglutination test and specificity of 93.4%, sensitivity of 96.0% positive predictive value of 90.5% and negative predictive value of 97.3%. From the results of our study, the agglutination test for group A streptococci is of diagnostic value. This new kit would be most useful in out-patient clinics, especially in a small private medical office without culture facilities.

Acute Disease↗
PubMed2005

Serological investigation of Theileria sergenti using latex agglutination test in South Korea.

Theileria sergenti causes persistent theileriosis in cattle, characterized by fever and chronic anemia. Theileriosis causes losses in feed efficiency and growth retardation through cycling infections in endemic areas. Among several major proteins of T. sergenti merozoites, the surface protein p33 is reported to be the most immunogenic. In this study, we investigated the use of p33 as a diagnostic antigen in a latex agglutination test to monitor antibodies against T. sergenti. When compared with TaqMan polymerase chain reaction, the sensitivity and specificity of the latex agglutination test were 86.5 and 92.5%, respectively. An epidemiological survey using the latex agglutination test was conducted with 1,046 sera collected from 4 slaughterhouses and 2 individual pasture farms throughout South Korea; 27.3% of samples were seropositive, depending on the areas in which the cattle were raised. This study indicated that the latex agglutination test could be used as a convenient tool for epidemiological monitoring of T. sergenti infections in the field.

Animals↗
PubMed1987

Latex agglutination test for alpha-fetoprotein in the diagnosis of premature rupture of the amniotic membranes (PROM).

A rapid latex agglutination test for alpha-fetoprotein (AFP) was compared with a pH-indicator and patient history in the detection of premature rupture of the amniotic membranes. Of 120 patients examined, 34 had an established rupture of the membranes, and 56 had suspected rupture. Thirty patients had no evidence of membrane rupture. The vaginal content was examined with a pH-indicator. Samples of vaginal content were also obtained to perform the latex agglutination test, and 103 of these samples were analysed by a radio-immunoassay (RIA) technique for AFP. Our results indicate that the latex agglutination test is of doubtful value due to the many inconclusive test results. The sensitivity of the latex test is less than 15%, and the specificity is 80%. Patient history combined with pH-indicator test is far more informative than the latex agglutination test.

Clinical Trials as Topic↗
PubMed1991

Diagnosis of snake venoms by a reverse latex agglutination test.

A reverse latex agglutination test using protein A column purified rabbit antivenom IgG-sensitized latex particles was developed for the detection of the six medically important snake venoms of Thailand. The detection limit of the reverse latex agglutination test was 0.16 to 1.2 micrograms/mL of crude venoms. Cross-reactions with heterologous venoms were observed at concentrations 460 to 16000 times that of homologous venoms. Detection of various snake venoms in clinical specimens was carried out by the reverse latex agglutination test. The sensitivity was 52.5% of the 59 serum samples. There was one (1.69%) false positive sample. The positive detection of venom in wound swabs (26 cases) was 38.5% and was not statistically different from that observed in paired serum samples. Interference from human plasma, serum and urine on the reverse latex agglutination test could be eliminated by adsorption with normal rabbit IgG-coated latex suspension or by heat inactivation at 56 degrees C for 30 min. Prozone effect observed in some sera was eliminated by heat inactivation at 56 degrees C for 30 min. The sensitized latex particles were stable at 4 degrees C and -20 degrees C for at least 3 months. Cycles of freezing-thawing and lyophilization did not change their reactivities. The total test time was about 40 min.

Adsorption↗
PubMed1999

Rapid identification of Burkholderia pseudomallei in blood cultures by latex agglutination using lipopolysaccharide-specific monoclonal antibody.

Melioidosis, an infection caused by Burkholderia pseudomallei, is endemic in Southeast Asia. The septicemic form of melioidosis is the leading cause of death due to community-acquired bacteremia in the northeastern part of Thailand. The delay in isolation and identification of the causative organism is a major contributing factor to the high mortality. The present study describes the evaluation of a latex agglutination test for rapid identification of the bacteria directly from blood cultures. The Bps-L1 monoclonal antibody recognized the lipopolysaccharide antigen of 96.8% of B. pseudomallei clinical isolates and was highly specific for B. pseudomallei. The diagnostic value of the latex agglutination test based on Bps-L1 monoclonal antibody was prospectively evaluated in an area endemic for melioidosis. The agglutination test kit was evaluated in 88 blood cultures with gram-negative bacteria identified with Gram staining. The sensitivity and specificity of the test kit were both 100%. These results indicated that the detection of B. pseudomallei lipopolysaccharide by specific monoclonal antibody in a latex agglutination format is clinically useful for the rapid identification of the bacteria in blood cultures in areas endemic for melioidosis.

Animals↗
PubMedDate not supplied

Evaluation of a commercial latex agglutination assay for screening for Clostridium difficile-associated disease.

OBJECTIVE: To determine if the Clostridium difficile latex agglutination assay is an effective screening procedure for the diagnosis of C. difficile-associated disease (CDAD). DESIGN: Convenience sample. SETTING: The Washington Hospital, a 364-bed, secondary, acute-care center in Washington, Pennsylvania. PARTICIPANTS: A total of 321 women and 195 men aged 21 days to 100 years. INTERVENTIONS: Diarrheal stool specimens from patients on antibiotic therapy were randomly tested for the presence of C. difficile-associated antigen by CULTURETTE brand latex agglutination assay (Beckton Dickinson Microbiology Systems, Cockeyesville, MD 21030). Latex-positive samples were confirmed or negated by cytotoxin assay using the Toxi-titer microtiter plate system (Baxter Healthcare Corp., Bartels Diagnostic Division, Issaquah, WA 98027). MAIN OUTCOME MEASURES: Comparative statistical analysis of the raw data to develop the sensitivity and specificity of the latex screening assay. RESULTS: Stool specimens of 403 patients (78.1%) were negative for C. difficile-associated antigen. Of the latex-positive specimens, 70 (69.3%) were also cytotoxin-positive. Of the indeterminate latex specimens, four (33.3%) were cytotoxin-positive. A total of 70 specimens (13.6%) were positive by both methods and 74 patients (14.3%) were diagnosed with CDAD. Based on this data, the latex agglutination screening assay had a sensitivity of 77.1% and a specificity of 93.4%. CONCLUSION: Latex agglutination for C. difficile-associated antigen is a moderately sensitive screening test for a presumptive diagnosis of CDAD. However, it is not the best screening test for CDAD compared with the new enzyme-linked immunosorbent assay (ELISA) techniques for toxins A and B.

Adolescent↗
PubMed1954

The unit in preference to the titre as a measure of agglutinating activity.

The agglutinating activity of individual sera is usually expressed by a "titre" notation, the titre being dependent on the degree of agglutination arbitrarily chosen as the end-point. This titre may be corrected by comparison with a standard serum. A "unit" notation, however, necessarily requires both comparative measurements in relation to a standard serum and the taking into consideration of all degrees of agglutination. This involves log-dose-response curves for the standard serum and the test serum; and cases in which the distance between such curves is not constant, either at different degrees of agglutination or where different antigen suspensions are used, will bring to light fundamental limitations of the bio-assay which the simple use of titres may not reveal.

Humans↗
PubMed2001

Tube and column agglutination technology for autocontrol testing.

The incidence of positive autocontrol test results with column agglutination technology is a concern. This study investigates the incidence and significance of positive autocontrols in the ID Micro Typing System (gel) and the Gamma ReACT (ReACT). The study encompassed a total of 1021 randomly selected samples from patients and 95 samples from donors collected during 1 month. The autocontrol testing was carried out according to the manufacturer's instructions for the column agglutination tests. The tube method was carried out using low-ionic-strength solution (LISS). The direct antiglobulin test (DAT) was performed using the tube method, and further investigated with elution studies if warranted. Seventy-nine patient's samples (7.74%) had a positive autocontrol: the gel test, 72 (91.13%); ReACT, 21 (26.58%); and the tube method, 27 (34.18%). Of the 79 positive autocontrols, 44 samples had a negative DAT. Of the samples with positive DAT results, only one possessed a clinically significant antibody, anti-D. Moreover, the same sample also tested positive in all three methods. Column agglutination techniques have increased sensitivity for a positive autocontrol beyond the conventional tube method. However, ReACT and gel tests differ significantly in their frequency of positives. Investigation of the significance of a positive autocontrol in column agglutination technology when the conventional tube method is also positive is suggested.

Journal Article↗
PubMed1992

Evaluation of the latex agglutination test for detection of Clostridium difficile.

We compared two Clostridium difficile latex agglutination tests, Meritec from Meridian Diagnostic (Cincinnati, Ohio) and CDT from Becton-Dickinson (Cockeysville, Md), on 289 specimens submitted for tissue culture cytotoxicity using MRC-5 cells. When compared with CDT, the Meritec latex agglutination test had a sensitivity of 90% (26/29), a specificity of 97% (251/260), and a correlation of 96%. Meritec was compared with tissue culture cytotoxicity on 357 specimens. Meritec had a sensitivity of 77% (30/39), a specificity of 93% (298/318), and a correlation of 92%. Clinical review of 10 Meritec +/- tissue culture cytotoxicity minus patients revealed one likely, two probable, and seven doubtful cases of C difficile disease. In contrast, review of 10 Meritec +/- tissue culture cytotoxicity plus patients showed seven likely and three probable cases of C difficile disease. The Meritec is comparable with the CDT latex agglutination test, but is not nearly as sensitive as either tissue culture assay or culture for detection of C difficile disease. A positive latex agglutination test should be confirmed by a tissue culture cytotoxicity assay.

Clostridioides difficile↗
PubMed2005

[Immunological analysis of pseudo-positive reaction in healthy adults at anti-streptolysin O measurement by latex agglutination method].

Streptolysin O (SLO) is a toxic immunogenic protein produced by Streptococcus pyogenes (S. pyogenes). The latex agglutination photometric immunoassay with latex coated by SLO (latex agglutination method) has been most widely used for determination of antibody to SLO (ASO). We measured ASO levels by latex agglutination method in serum specimens collected from 159 healthy individuals and eight patients with S. pyogenes, who had a positive S. pyogenes culture from throat swabs. A significant frequency(about 15%) had positive ASO levels (> 200 unit/ml) in healthy individuals aged < 20 (47 individuals) and 20-29 (80 individuals), respectively, however, none of 30 or over (32 individuals) were positive. The SLO specimen purchased from Sigma Chemical Co. showed at least three protein bands on SDS-PAGE; one was considered SLO protein because it had a molecular weight of 64 kD and of the remaining proteins, one had a molecular weight higher and the other had a molecular weight lower than 64 kD. Serum antibodies among the healthy adults to Sigma-SLO specimen consisted of IgG class in the majority, with little IgM class. Immunoblotting analysis revealed that serum antibodies of the patients recognized the 64-kD protein (SLO), and serum antibodies of the healthy adults recognized different proteins from SLO. It appeared that many of the healthy adults with a positive ASO level had antibodies different from ASO, resulting in pseudo-positive ASO values when ASO was measured by latex agglutination method using SLO specimen containing non-specific proteins. Improvement of commercial kits using this method is required.

Adult↗