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Recombinant galectins of male and female Haemonchus contortus do not hemagglutinate erythrocytes of their natural host.

Recombinant galectins of female and male adult worms of Haemonchus contortus were expressed in Escherichia coli and their hemagglutinating activities to human and different animal erythrocytes were analyzed. The results showed that female and male galectins could be highly expressed in E. coli using a temperature-sensitive plasmid, with the recombinant protein being mainly appeared in inclusion bodies. Hemagglutinating activity assays showed that both of the galectins hemagglutinated human A, B, O type, dog, rabbit, chicken and mouse erythrocytes at the high concentration of 40 microg/well, but did not hemagglutinate erythrocytes of the natural host of H. contortus, the goat. Sugar inhibition assays confirmed that, out of eight sugars tested, only lactose was effective to inhibit agglutination of human type B erythrocytes by the recombinant galectins.

Animals↗

[HBs antigen screening with Groupamatic. Inhibition of passive hemagglutination and latex test].

Some agglutination tests for HBs Ag and anti-HBs detection may be easily automated. Reverse hemagglutination, needing a lengthy incubation and several steps to carry out is unfit for Groupamatic, but hemagglutination inhibition and latex agglutination may be used. Hemagglutination inhibition using selected human red cells (ORh+) coated with cesium chloride purified HBs Ag, has been now routinely used at the C.N.T.S. with visual reading for almost 2 years. Negative and positive controls are necessary. The anti-HBs serum utilized has to be checked daily to get sensitive detection. Every new batch of coated red cells (valid 4 to 6 weeks) is checked in microtiter plates in the laboratory, before being used on Groupamatic. Both positive and dubious results are systematically retested in RIA. We found only 0,5% of false positive. The sensibility of the test compared favourably with other third generation test as reverse hemagglutination. It was close to the results obtained with radio-immuno-assay or enzyme-immuno-assay and it was more sensitive than counter-immuno electrophoresis. 65,472 samples were tested in parallel: we were able to detect 97% of HBs Ag detected by RIA. False negative results were less than 1 per 10 000 and may be avoided by using citrated solution for the anti-HBs serum dilution (suppression of auto-agglutination of the red cells). Antigex TG (the most active batch of latex coated with guinea pig, anti-HBs antibody) made by Pfizer, gave good results on Groupamatic and automatic reading was possible. But more results are necessary using various batches, before to recommend such reagent.

Autoanalysis↗

Hemagglutination inhibition of Cromer blood group antibodies with soluble recombinant decay-accelerating factor.

BACKGROUND: Cromer blood group antigens are located on decay-accelerating factor (DAF, CD55), which contains four short consensus repeats (SCRs). Cromer system antibodies may be of clinical significance in blood transfusion. STUDY DESIGN AND METHODS: Soluble recombinant DAF (srDAF) constructs, consisting of all four SCRs or of only two SCRs, were expressed in the yeast Pichia pastoris. They are used in hemagglutination-inhibition tests with Cromer system antibodies and with DAF-specific monoclonal antibodies. RESULTS: The srDAF inhibited hemagglutination by all Cromer system alloantibodies in undiluted serum. Antibodies to antigens of other blood group systems were not inhibited by the srDAF. Hemagglutination-inhibition tests with domain-deleted srDAF showed that UMC is on SCR-4 and confirmed that Tca, TcaTcb, and WESb are on SCR-1; Dra is on SCR-3; and Cra is on SCR-4. CONCLUSIONS: Hemagglutination inhibition with srDAF is useful in the recognition of antibodies that belong to the Cromer blood group system and facilitates pretransfusion testing. This use of domain-deleted srDAF provides an easy method of determining epitope location on DAF and is an aid to more precise identification of Cromer system antibodies.

Blood Group Antigens↗

Rubella antibody assay by the immunoperoxidase technique: comparison with the hemagglutination inhibition test for determination of immune status.

The rubella immune status of 128 young women was determined with two assays for rubella antibody, the immunoperoxidase technique and the hemagglutination inhibition test. Comparison of the results of these techniques showed agreement in 125 cases (110 positive and 15 negative). Positive results were obtained for one woman only by the immunoperoxidase assay and for two women only by the hemagglutination inhibition test; all three of these women had a minimal titer of rubella antibody of 1:16. The sensitivity of the immunoperoxidase test was comparable to that of the hemagglutination inhibition test, and the specificity of the former test was verified. The peroxidase-labeled antibody technique is easier to perform than the hemagglutination inhibition test and is less time-consuming since sera do not require prior treatment and results can be obtained in as little as 90 min.

Antibodies, Viral↗

A passive hemagglutination test for diagnosis of trench fever due to Rochalimaea quintana.

A passive hemagglutination test devised for diagnosis of trench fever was easily performed and highly sensitive and specific. Tanned sheep erythrocytes were sensitized with soluble antigen from Rochalimaea quintana. The test detected antibody in six of seven cases of primary infection and in four cases of late, relapsed trench fever. Titers of antibody ranged from 1:20 to 1:640. Although both IgM and IgG antibody to R. quintana were detected by passive hemagglutination, IgG appeared to be the major reactive antibody. Antigens involved in the reaction were two types of proteins, one inactivated at 50 C and 60 C and the other at 80 C and 100 C. Of 322 control samples of sera that were tested, only one reacted positively; thus, the test had a specificity of greater than 99%. The single positive reaction was in serum from a patient with Q fever. This finding suggests that, in an area where Q fever is endemic, this disease must be ruled out in the interpretation of a positive passive hemagglutination test. Sera should be tested routinely against tanned, unsensitized erythrocytes, since an occassional sample of serum may agglutinate unsensitized cells. Because of its sensitivity and specificity, as well as its simplicity of performance, the passive hemagglutination test shows promise as a useful procedure for serologic identification of both acute and past infection with R. quintana.

Antibodies, Bacterial↗

Hemagglutination, adherence, and surface properties of vaginal Lactobacillus species.

To address the poorly understood mechanisms through which lactobacilli adhere to vaginal epithelial cells (VECs), 65 wild type lactobacilli isolated from the vaginal flora of young women and 3 American Type Culture Collection Lactobacillus strains were studied. Group I isolates (n = 56) hemagglutinated sheep, rabbit, and human red blood cells (RBCs) and adhered poorly to VECs. In contrast, all 4 group II strains hemagglutinated sheep and human but not rabbit RBCs, adhered in large numbers to VECs, and were identical in five phenotypic tests and DNA-DNA hybridization. Eight other strains (group III) hemagglutinated all RBC types studied, adhered avidly to VECs, and had identical protein and hybridization patterns but showed heterogeneous enzyme activities. Although most wild type lactobacilli from the vaginal flora of young women adhered poorly to VECs, selected isolates (groups II and III) adhered in large numbers, demonstrated specific and reproducible hemagglutination patterns, and may have specific mechanisms of attachment to VECs.

Animals↗

Hemagglutination-inhibition method and immunofluorescence staining with Venezuelan equine encephalomyelitis virus.

Hemagglutination and fluorescent antibody (FA) are compared for the direct detection of virus devoid of host cells. A determination was made of the minimal number of tissue plaque-forming units of Venezuelan equine encephalomyelitis virus that could be detected by the hemagglutination technique. Similar concentrations of the virus in bovine albumin borate saline, Brain Heart Infusion broth (Difco), and demineralized water were tested by the FA technique. Somewhat higher concentrations of the virus in bovine albumin borate saline were used in the hemagglutination-inhibition test. The quantitative hemagglutination procedure employed for these studies was carried out at 37 C for 75 min with variations in concentration of goose red cells. As a result of lowering the red cell concentration, smaller concentrations of virus were detected. The direct FA staining procedure applied to slide preparations containing known numbers of tissue culture plaque-forming units of virus was negative. Adsorbed viral antigen on agglutinated goose erythrocytes was visualized by direct and indirect FA techniques.

Culture Media↗

Antigens of group A streptococci involved in passive hemagglutination reactions.

Antibodies to streptococcal extracellular products were detected in rabbit sera by passive hemagglutination tests as early as 1 week after intravenous injection of live group A streptococci (strain C203S). Using these antibodies in immunoadsorbent columns, we prepared an antigenic fraction from crude concentrates of streptococcal extracellular products. The specific activity of this fraction in sensitizing glutaraldehyde-treated erythrocytes for passive hemagglutination tests and in absorbing passive hemagglutination antibodies from immune sera was increased by 80-fold and at least 24-fold, respectively, as compared with crude extracellular products. The fraction has been found to contain at least three serologically active antigens, which are of considerable interest because: (i) they gave rise to early and consistent immune responses both in humans and in experimental animals; (ii) they appear so far to be produced only by beta-hemolytic streptococci; and (iii) antibodies to these antigens are present in high titers in patients with acute rheumatic fever. Our data suggest that passive hemagglutination antigens may be distinct from those extracellular enzymes and hemolysins ordinarily employed in streptococcal serological studies.

Animals↗

Hemagglutination of human type O erythrocytes, hemolysin production, and serogrouping of Escherichia coli isolates from patients with acute pyelonephritis, cystitis, and asymptomatic bacteriuria.

The purpose of this investigation was to study potential virulence factors associated with Escherichia coli urinary pathogens isolated from patients with urinary tract infection. These factors were compared with characteristics of normal-flora E. coli isolated from stool specimens of healthy individuals without a history of urinary tract infection. The potential virulence factor focused on in this study was hemagglutination (HA) of human type O erythrocytes by E. coli urinary pathogens. A total of 265 strains of E. coli isolated from patients with urinary tract infections were tested for their ability to hemagglutinate human type O erythrocytes; of these, 148 (56%) were HA positive. Only 6 of 36 fecal E. coli strains (17%) isolated from healthy controls were HA positive. This significant association of the presence of hemagglutinin on E. coli that causes urinary tract infections indicates the likelihood that HA is a marker of virulence. Only 12% (5 of 43) of Proteus mirabilis and 3% (3 of 104) of Klebsiella pneumoniae urinary isolates were HA positive. There was a trend for HA-positive E. coli to be isolated from patients with kidney infections and positive tests for antibody-coated bacteria rather than bladder infections and negative tests for antibody-coated bacteria, although the difference was not statistically significant. There was a significant correlation (P < 0.025) between hemolysin production and HA; 67% (69 of 103) of the isolates that produced hemolysin also hemagglutinated human type O erythrocytes. There was no significant correlation between HA and motility, although there was a trend for flagellated organisms to be non-hemagglutinators. There was a marked correlation between the presence of hemagglutinin and the serogroup of the E. coli isolate; serogroups O4, O7, and O50 were almost always HA positive (57 of 63; 90%). In contrast, serogroups O8 and O25 were rarely HA positive (2 of 30; 7%).

ABO Blood-Group System↗

Adhesion, hemagglutination, and virulence of Escherichia coli causing urinary tract infections.

The capacity of 453 Escherichia coli strains to agglutinate erythrocytes and yeast cells and to attach to human urinary tract epithelial cells was tested. The strains were isolated from the urine of patients with acute pyelonephritis, acute cystitis, or asymptomatic bacteriuria and from the stools of healthy school children. Three main patterns of hemagglutination were found: (i) mannose-resistant agglutination of human erythrocytes alone or simultaneously with mannose-sensitive agglutination of guinea pig erythrocytes; (ii) only mannose-sensitive agglutination of guinea pig and other erythrocytes; and (iii) no agglutination. Strains with mannose-resistant agglutination of human erythrocytes alone or in combination with mannose-sensitive hemagglutination attached in high numbers to human urinary tract epithelial cells. Bacteria inducing only mannose-sensitive hemagglutination attached in low numbers, and non-agglutinating strains did not bind to the urinary tract epithelial cells. The bacterial surface antigen(s) mediating mannose-resistant hemagglutination of human erythrocytes and attachment to human urinary tract epithelial cells may be one factor selecting for E. coli from among the fecal flora which infect the urinary tract. The highest proportion of strains with this property was found among acute pyelonephritis isolates (77%), and the lowest proportion of strains with this property was found among normal fecal E. coli (16%).

Agglutination↗

Enhancement of hemagglutination inhibition by complement.

Experiments were conducted to determine the effect of specific antibody and complement on hemagglutination inhibition of influenza virus. It was found that early immunoglobulin M antibody to influenza virus inhibited the hemagglutinating capacity of the virus. When fresh guinea pig serum was added, the inhibiting capacity of the serum was elevated from four- to eightfold When guinea pig serum was treated with known complement inhibitors, it lost its capacity to enhance hemagglutination. The use of functionally purified complement components indicated that the first, second, and fourth components were necessary and sufficient for enhancement of hemagglutination inhibition by specific antibody to influenza virus.

Animals↗

Comparison of hemagglutinating pili of Haemophilus influenzae type b with similar structures of nontypeable H. influenzae.

Thirty-eight clinical isolates of nontypeable Haemophilus influenzae were tested for the presence of hemagglutinating pili similar to those of H. influenzae type b (Hib) that mediate buccal epithelial cell adherence. Four endogenously hemagglutinating (HA+) strains were identified, and eight additional HA+ variants were obtained from HA- strains by erythrocyte enrichment. All 12 HA+ nontypeable H. influenzae isolates bound antisera directed against denatured pilins of Hib, but none bound antisera against assembled native pili of Hib. In erythrocyte- and buccal-cell-binding assays, HA+ nontypeable H. influenzae binding was reduced compared with HA+ Hib binding and was not significantly different from HA- nontypeable H. influenzae binding. Both HA- and HA+ nontypeable H. influenzae binding was increased over binding of HA- Hib. HA+ nontypeable H. influenzae strains agglutinated adult erythrocytes that possess the Anton antigen, which is thought to be the receptor for Hib pili, and did not agglutinate cord or Lu(a-b-) dominant erythrocytes, which lack the Anton antigen. Electron microscopy of HA- and HA+ variants of three nontypeable H. influenzae strains showed few or no surface appendages on the HA- organisms, but piluslike structures were seen on many organisms from two HA+ nontypeable H. influenzae strains and on a few organisms from one strain. Thus, nontypeable H. influenzae appears to possess structures that are immunologically similar to the pilins that make up the hemagglutinating pili of Hib. However, nontypeable H. influenzae appears to also possess mechanisms for erythrocyte and buccal cell adherence that are not directly correlated with the presence of a hemagglutinating pilus.

Bacterial Adhesion↗

Hemagglutinating and chemotactic properties of synthetic peptide segments of fimbrial protein from Porphyromonas gingivalis.

Porphyromonas gingivalis 381 fimbriae, their synthetic peptide segments, and lipopolysaccharide (LPS) were examined for hemagglutinating and migration-stimulating activities. P. gingivalis 381 fimbriae clearly caused hemagglutination, and several oligopeptide segments such as FP381(61-80), FP381(171-185), and FP381(302-321), corresponding to the amino acid residue numbers based on the amino acid sequence of fimbrillin proposed by Dickinson et al. (D. P. Dickinson, M. A. Kubiniec, F. Yoshimura, and R. J. Genco, J. Bacteriol. 170:1658-1665, 1988), were also demonstrated to agglutinate erythrocytes although less effectively than the native fimbriae. Furthermore, P. gingivalis 381 LPS but not Escherichia coli O55:B5 LPS definitely exhibited hemagglutination. P. gingivalis fimbriae as well as their synthetic peptides possessing hemagglutinating activity enhanced the chemotaxically induced migration of human peripheral blood monocytes. The results of the analyses using synthetic peptide FP381(61-80), its related compounds, and an analog suggested that the amino acid sequence XLTXXLTXXNXX within fimbrial protein molecules may play an important role structurally in the attachment of the protein to host cells such as erythrocytes and monocytes.

Amino Acid Sequence↗

Improved indirect hemagglutination test for cytomegalovirus using human O erythrocytes in lysine.

A modified indirect hemagglutination test for cytomegalovirus antibodies is described in which glutaraldehyde-fixed human O cells, rather than sheep cells, are used. Nonspecific hemagglutination was reduced by use of the optimal tannic acid concentration for each cell batch and the addition of 0.1 M lysine to the phosphate-buffered saline in which the fixed, tanned, sensitized cells were resuspended for use in the test. Three of 349 sera showed nonspecific hemagglutination by this technique. Antigen made by freezing phosphate-buffered saline (pH 7.2) over an infected monolayer can be used at dilutions of 1:8 to 1:15. Fixed, tanned, sensitized cells ready for use in the test can be stored in liquid nitrogen for up to 8 months. Use of cryoprotectants and washing after thawing is unnecessary. Simplification of the assay permits one person to screen 300 sera in 1 day or to determine the immune status of a potential donor or recipient in 45 min after the test is set up. The modified assay compares favorably in sensitivity with the complement fixation test and with previously described methods for performing the indirect hemagglutination test.

ABO Blood-Group System↗

Indirect hemagglutination test for pseudorabies antibody detection in swine.

An indirect hemagglutination test for the detection of antibodies in swine serum specific for pseudorabies virus is described. The indirect hemagglutination test was less time consuming than the standardized virus nertralization test while being highly sensitive and accurate. Serum samples that were toxic to virus neutralization indicator cells were readily tested in the indirect hemagglutination test. The indirect hemagglutination test may also be more sensitive than the virus neutralization test for determining early titers in pseudorabies virus infections. Complete methodology is described.

Animals↗

Candida antigenemia, as detected by passive hemagglutination inhibition, in patients with disseminated candidiasis or Candida colonization.

A passive hemagglutination inhibition assay was studied by using a hyperimmune serum from rabbits immunized with whole yeast cells (Candida albicans group A). This technique was effective at detecting small amounts of laboratory-prepared mannan or a whole-cell extract of C. albicans. Of 32 patients with documented disseminated candidiasis that were tested, 19 showed evidence of circulating antigen by passive hemagglutination inhibition. Three of these patients showed only partial, rather than complete, inhibition. Among 22 colonized patients, 4 showed partial inhibition, and none of 49 normal controls demonstrated inhibition. All of the sera were tested for antibody by agglutination, immunodiffusion, and passive hemagglutination. This last technique added increased sensitivity, but not specificity, to the standard tests already in use. Fourfold or greater titer rises by passive hemagglutination occurred in fewer than one-third of patients with invasive candidiasis and developed in more than one-half of patients who were colonized and did not require systemic anticandida therapy.

Antibodies, Fungal↗

Evaluation of an indirect hemagglutination test for Legionella pneumophila serogroups 1 to 4.

Parallel testing of 895 sera by indirect hemagglutination and indirect fluorescent-antibody techniques showed 97.3% agreement. Although the indirect hemagglutination technique usually showed more cross-reactivity among serogroups than the indirect fluorescent-antibody technique with Formalin-fixed antigens and a conjugate which detected primarily immunoglobulin G antibodies, heterologous serogroup reactions were significantly lower than homologous serogroup titers and the etiological serogroup could be easily defined. The indirect hemagglutination techniques showed no cross-reactivity with a crude extract of Escherichia coli O13:K92:H4. Since the indirect hemagglutination technique was shown to detect both immunoglobulin M and immunoglobulin G antibodies and was found to be rapid, simple, and inexpensive, it appears to be an excellent alternative to the indirect fluorescent-antibody test for serodiagnosis of legionellosis.

Antibodies, Bacterial↗

Serological diagnosis of influenza B virus infection: comparison of an enzyme-linked immunosorbent assay and the hemagglutination inhibition test.

The sensitivity of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibody to influenza B virus was compared with that of the hemagglutination inhibition test on acute- and convalescence-phase sera obtained from adults and children infected with influenza B virus. Two whole virus, tissue culture-grown antigen preparations were used in the ELISA, influenza B/West Virginia/81 and influenza B/Hong Kong/72. Four antigens were used in the hemagglutination inhibition test. These included the tissue culture-grown whole virus antigens that were used in the ELISA. In addition the standard egg-grown antigens, influenza B/Singapore/79 and influenza B/Hong Kong/72, were included for comparison. The ELISA antibody titer was significantly correlated to the hemagglutination inhibition antibody titer, and 10 of 10 adults and 17 of 21 children infected with influenza B had fourfold antibody increases as detected by ELISA with either antigenic type of tissue culture-grown whole virus. Increases in geometric mean antibody titers of 16- to 71-fold were detected by ELISA. Increases in geometric mean antibody titers of 3- to 10-fold were detected by hemagglutination inhibition depending on the type of antigen utilized. We found that ELISA with whole virus antigens was a sensitive and specific test for the detection of antibody to influenza B virus.

Adult↗