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Enterotoxigenicity, hemagglutination and cell-surface hydrophobicity in Aeromonas hydrophila, A. sobria and A. salmonicida.

Thirty-one Aeromonas hydrophila, 13 A. sobria and two A. salmonicida strains of diverse sources were tested for enterotoxigenicity, hemagglutination and cell surface hydrophobicity. Although 93% of the culture supernatant fluids of the Aeromonas strains exhibited cytotoxic effects on Y1 adrenal and Chinese hamster ovary (CHO) cells, typical rounding of Y1 adrenal cells was reproducibly observed before cytotoxicity for 80% of the isolates within 1 h of exposure. Twenty-eight strains were positive for delayed permeability factor (DPF) activity in rabbit skin. Culture filtrates of 16 of 20 strains that were positive both in the Y1 adrenal cell test and for DPF activity elicited fluid accumulation in rabbit ileal loops. The DPF and ileal loop activities were neutralizable by cholera antitoxin. All, except two strains each of A. sobria and A. hydrophila, produced a heat-stable, rapid permeability factor (RPF) detected in rabbit skin. Heat-treated culture supernatant fluids of two A. hydrophila and one A. sobria isolate gave positive responses in the infant mouse assay. Nine other strains gave borderline reactions. When A. hydrophila and A. sobria isolates were grown in broth, approximately 90% agglutinated bovine, chicken, human group A and guinea-pig erythrocytes in the presence of mannose at 4 degrees C and/or 20 degrees C. The two A. salmonicida isolates produced mannose resistant hemagglutination (MRHA) of these four blood types. Hydrophobic interaction chromatography indicated adhesive potential in 61% A. hydrophila and 100% A. sobria strains expressing weak to strong hydrophobic cell surface properties. The results of these investigations strongly imply that the Aeromonas strains produce a cytotonic enterotoxin immunologically related to cholera toxin. Adhesive characteristics were commonly found in both clinical and routine isolates.

Aeromonas↗

A rapid assay of the sialidase activity in species of the Bacteroides fragilis group by using peanut lectin hemagglutination.

In this study, a novel, simple and rapid hemagglutination assay by using a peanut lectin to detect a neuraminidase activity in strains of the Bacteroides fragilis group was developed. One hundred and fourteen species of the B. fragilis group isolated from children with and without diarrhea and 15 reference strains were evaluated. Neuraminidase production was determined by using the method above described and its inhibition was observed by using galactose. The neuraminidase production was observed in 54 (84.37%) diarrhea and in 43 (86%) non-diarrhea strains. HA titers were ranged from 2 to 32. This neuraminidase assays based on PNA hemagglutination is highly sensitive, reproducible and could be used as a tool to detect the sialidase activity in anaerobic bacteria, particularly, in species of the B. fragilis group.

Bacteroides fragilis↗

Antibodies produced against a fragment of filamentous haemagglutinin (FHA) of Bordetella pertussis are able to inhibit hemagglutination induced by the whole adhesin.

Filamentous hemagglutinin adhesin (FHA) is important for the adherence of Bordetella pertussis to the host ciliary epithelial cells of the respiratory tract. Several binding domains have been characterized in the FHA molecule. For example, an putative heparin-binding domain of FHA was previously located in the FHA(442-863) region. In this work, the HEP fragment, corresponding to FHA(430-873) was amplified by PCR and subcloned in an Escherichia coli expression plasmid. Purified recombinant HEP was used to produce polyclonal antibodies in mice that were able to recognize HEP and FHA in ELISA and in Western-blot assays. Although recombinant HEP displayed low ability to bind heparin and no hemagglutination activity, the anti-HEP antibodies were able to inhibit FHA mediated hemagglutination activity in goose erythrocytes. These results indicate that other amino acid residues that are not present in the FHA(430-873) fragment may be necessary for heparin binding. Further studies to address the immunogenic response against HEP are also required.

Adhesins, Bacterial↗

Measurement of antibodies to avian influenza virus A(H7N7) in humans by hemagglutination inhibition test.

During the epizootic of highly pathogenic avian influenza A(H7N7) in 2003 in The Netherlands, RT-PCR and culture confirmed infection was detected in 89 persons who were ill. A modified hemagglutination inhibition (HI) test using horse erythrocytes and 2 hemagglutinating units of virus was applied to assess retrospectively the extent of human (subclinical) infection. Validation of the HI-test with sera from 34 RT-PCR and culture confirmed A(H7) infected persons and sera from 100 persons from a human influenza vaccine trial in autumn 2002 showed that this HI-test had a sensitivity of 85% and a specificity of 100% when using a cut-off titer of > or =10. Using this cut-off value, A(H7) specific antibodies were detected in 49% of 508 persons exposed to poultry and in 64% of 63 persons exposed to A(H7) infected persons. Correlation of seropositivity with the occurrence of eye symptoms in exposed persons who had not received antiviral prophylaxis and of reduced seropositivity with taking antiviral prophylaxis provided further evidence that the A(H7) HI antibody titers were real. In conclusion, by applying an HI-test using horse erythrocytes human antibodies against the avian A(H7N7) virus were detected with high sensitivity and specificity in an unexpectedly high proportion of exposed persons.

Adolescent↗

Construction of novel human monoclonal antibodies neutralizing Porphyromonas gingivalis hemagglutination activity using transgenic mice expressing human Ig loci.

Porphyromonas gingivalis has been implicated as an important pathogen in the development of adult periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. One potential virulence factor, hemagglutinin, may mediate bacteria attachment onto and penetration into host cells, as well as agglutinate and lyses erythrocytes to intake heme, an absolute requirement for growth. Toward the development of passive immunotherapy, the construction of a human type monoclonal antibody, which is capable of inhibiting the hemagglutinating ability, will be significant and important. The human mAbs, both exhibiting a high degree of specificity and affinity against the recombinant 130 kDa hemagglutinin domain protein have been prepared using XenoMouse technology. The constructed Xeno-mAbs, IgG2 subclass, significantly inhibited hemagglutination of P. gingivalis and its vesicles. The newly constructed Xeno-mAbs may prove to be useful for the development of passive immunization against periodontal diseases caused by P. gingivalis infection, pending the results of fertility study in disease mode.

Animals↗

The reaction of Campylobacter species on the chemiluminescence, chemotaxis and hemagglutination.

The influence of Campylobacter species (sp.) on the luminol-dependent chemiluminescence (CL) during phagocytosis, the chemotaxis and the agglutination of different erythrocyte species was investigated. CL was measured directly with undiluted whole blood samples and isolated polymorphonuclear neutrophil granulocytes (PMNG). The chemotactic response of PMNG to various Campylobacter sp. was performed using an agarose technique. All the Campylobacter sp. investigated showed a different CL response pattern. When opsonized Campylobacter strains were used, the CL response of PMNG was greater than in the presence of nonopsonized strains. No correlation was found between CL response and bacterial killing. For the investigation of the chemotaxis the filtered supernatants of Campylobacter cultures were used as cytotoxins and compared with the chemotactic peptide, formyl-methionyl-leucine-phenylalanine (FMLP). All the supernatants of cultures of Campylobacter sp. were chemotactic for PMNG. A strong mannose-resistant hemagglutination (MRHA) with glycine-hydrochloride extract was observed with C. fetus ssp. fetus and a weak reaction, with C. coli. There was no correlation between chemiluminescence, chemotaxis and hemagglutination. The weak stimulation of PMNG by C. fetus ssp. fetus and most of the C. jejuni/coli isolates suggest that this behavior could be a cause of pathogenicity.

Campylobacter↗

Incidence of hemagglutination-inhibiting antibodies for Bhanja virus in humans along the north-west border of Yugoslavia.

By the hemagglutination-inhibition test with the Yugoslav strain of Bhanja virus, the sera of 380 youngsters residing in the region along the Yugoslav-Hungarian border (North Croatia) and 367 sera from newcomers to the area from various parts of Yugoslavia were examined. The testing included 154 sera of the youngsters who had came to the region along the Yugoslav-Italian border (Slovenia) without antibodies for Bhanja virus and were staying there for a year. Hemagglutination-inhibiting antibodies for BHA virus were found in the sera of 5.53% examined natives of North Croatia, while in the newcomers after one-year stay in the area HI antibodies for the virus were confirmed in 3.27% of the sera examined. HI antibodies for BHA virus were found in 1.95% sera of the 154 youngsters who had come to the study area along the Yugoslav-Italian border (after one-year stay in the area). These results suggest a recent circulation of Bhanja virus in the regions studied. It is important to point out that the presence of the tick Haemaphysalis punctata, the principal vector of Bhanja virus in Europe, was evidenced in both regions.

Adolescent↗

Lectins in fruits having gastrointestinal activity: their participation in the hemagglutinating property of Escherichia coli O157:H7.

BACKGROUND: In fruits with therapeutic properties for antidiarrheal and laxative uses, the presence of lectins may be the bioactive properties that interfere with bacterial adhesion, thought to be competition for glycoside signal sites in the attachment. METHODS: This study identifies lectins in crude extracts from fruits such as Tamarindus indica (tamarind), Spontia vulgaris (plum), Psidium guava (guava), Mangifera indica (mango), Cydonia vulgaris (quince), and Crataegus mexicanus (tejocote). To verify the procedures, extracts from Ricinus communis (castor bean), Glycine max (soybean), Phaseolus vulgaris (beans), Vicia fava (fava bean), and Solanum tuberosum (potato) were used as controls for lectin activity. Both sources of lectins were analyzed to determine their participation in the host-parasite interaction, using as a model the hemagglutinating properties of Escherichia coli O157:H7 (EHA). RESULTS: All extracts showed hemagglutination to group O erythrocytes test (HA) with the exception of mango. Two new galactose-specific lectins were identified from tamarind and guava. When analyzed for participation in EHA, only guava lectins inhibited this, while soybean lectin induced hemolysis; as both lectins bind to galactose, it is probable that their recognition occurs in different domains. Sugars involved in the attachment between Escherichia coli O157:H7 and red cells were identified and again, galactose in addition to mannose was found to be related in EHA. On the other hand, guava lectins also agglutinated E. coli O157:H7, perhaps due to the same galactose-specific lectin or to another type of lectin. CONCLUSIONS: In summary, guava has a galactose-specific lectin that prevents adhesion of E. coli O157:H7 to red cells; this lectin is mediated by galactose. Prevention could also be due to their capacity of agglutinating E. coli by guava lectins. Soybean lectin induced hemolysis only when bacteria was present, but not with floating secretions. This finding showed that guava is a source of lectin that can be explored to prevent adhesion of E. coli to epithelial intestinal cells; contrariwise, soya must be studied to see its participation in the uremia caused during E. coli O157:H7 pathogenesis.

Bacterial Adhesion↗

[Application of a reversed passive hemagglutination test to the detection of HBs antigen].

In this report we present an evaluation of the sensitivity, specificity and ability to detect HBs Ag carriers of a new reversed passive hemagglutination test, using immunochemically purified chimpanzee anti HBs bound to stabilized human erythrocytes. The method was shown to have a sensitivity equal (within one two fold dilution) to that of the Ausria I 125 ratio immuno assay, and in a double blind comparison detected essentially the same number of Hbs Ag containing specimens among volunteer blood donors. The method therefore provides an economical method for the third generation testing of blood donors. The methodology which has been described incorporates a definitive specificity test in which serum drawn before and after immunization of chimpanzees with purified HBs Ag is compared for its ability to neutralize the hemagglutination reaction. The use of serum from the same animal for this purpose avoids the theoretical possibility that antiglobulin antibodies directed at subclass determinants such as Gm of Inv could be differentially inhibited due to possible subclass differences in the blocking sera employed. A reliable test for specificity of HBs Ag screening results is essential to avoid false notification of donors that they are carriers of hepatitis B virus.

Animals↗

Determination of immunity to measles virus in young adults: comparative evaluation of a commercial enzyme immunoassay and the hemagglutination inhibition techniques.

BACKGROUND: Determination of the immune status against measles in young adults requires careful evaluation of the laboratory methods because of waning immunity. The hemagglutination inhibition (HI) test and enzyme-linked immunosorbent assay (ELISA) may lack the sensitivity required to detect very low levels of antibodies. In addition, the correlation between ELISA-IgG assays and the degree of protection from measles is not well defined. OBJECTIVES: (a) Evaluation of a commonly used measles ELISA-IgG test kit in comparison with the hemagglutination inhibition (HI) test which corresponds strongly to virus neutralization; (b) determination of false negative rates of the ELISA-IgG and the HI tests; (c) evaluation of the ELISA-IgG test kit as a quantitative assay. STUDY DESIGN: One hundred and eighty serum samples collected from 60 vaccinated young adults immediately before vaccination and 14 and 28 days postvaccination, were tested comparatively by HI and by a commercial ELISA-IgG kit. For evaluation of false negative rates, postvaccination sera of a cohort of 48 vaccinees with negative HI or ELISA-IgG prevaccination sera were tested for IgM. Sixty-three of the samples were also titrated by the ELISA-IgG kit using serial dilutions, for comparison with HI titers. RESULTS: Using the HI test as a reference method, the ELISA-IgG kit was found to have overall accuracy of 81%, sensitivity of 80% and specificity of 84%. The false negative and the false positive rates were 20% and 16%, respectively. In contrast, when we used postvaccination IgM test to distinguish between true and false prevaccination negatives in both the HI and ELISA-IgG tests, we found that the false negative rates were 75.6% by ELISA and 72.5% by HI, and false positive rates were 2.4% and 0%, respectively. Serum titers determined by the ELISA-IgG test were generally 5-10-fold higher than the corresponding HI titers, but without a consistent correlation. CONCLUSIONS: Both the ELISA-IgG and the HI tests frequently failed to detect residual immunity. The two tests also did not correlate well with each other suggesting that different antigenic determinants of the virus are involved in each assay and therefore the HI test should not be used as a reference method for evaluation of the sensitivity of ELISA IgG kits.

Adolescent↗

Correlation between serum estradiol in the follicular phase of the ovarian cycle and decay acceleration factor (DAF) expression on red blood cells and coxsackiervirus B-3 induced hemagglutination in young cycling women.

Decay accelerating factor (DAF) is a widely distributed glycoprotein which aids in the inactivation of complement. DAF is also a cellular receptor for certain group B coxsackieviruses (CVB) and is responsible for the viral hemagglutinating activity for human red blood cells (RBC). Healthy, young female volunteers donated blood on days 11 and 22 of the ovarian cycle. Samples were categorized into luteal and follicular phases based on serum progesterone level (P4 either < 2.0 ng/mL, follicular; P4 > or = 2.0 ng/mL, luteal) and analyzed by flow cytomtery for DAF expression on RBC and CD21 + B lymphocytes. Cycling females showed significant variation in CVB-induced hemagglutination and % RBC or CD19 + cells which were DAF +. There was a strong correlation between serum estradiol levels and % RBC expressing DAF (P < 0.01) in the follicular, but not in the luteal ovarian phase. Infection of white blood cells with green-fluorescent protein CVB (GFP-CVB) showed a correlation between infectivity of CD19+ cells and DAF expression. This indicates that women may show differential susceptibility to CVB infection in the luteal and follicular phases of the ovarian cycle.

Antigens, CD19↗

Genetic analyses of proteolysis, hemoglobin binding, and hemagglutination of Porphyromonas gingivalis. Construction of mutants with a combination of rgpA, rgpB, kgp, and hagA.

Porphyromonas gingivalis produces arginine-specific cysteine proteinase (Arg-gingipain, RGP) and lysine-specific cysteine proteinase (Lys-gingipain, KGP) in the extracellular and cell-associated forms. Two separate genes (rgpA and rgpB) and a single gene (kgp) have been found to encode RGP and KGP, respectively. We constructed rgpA rgpB kgp triple mutants by homologous recombination with cloned rgp and kgp DNA interrupted by drug resistance gene markers. The triple mutants showed no RGP or KGP activity in either cell extracts or culture supernatants. The culture supernatants of the triple mutants grown in a rich medium had no proteolytic activity toward bovine serum albumin or gelatin derived from human type I collagen. Moreover, the mutants did not grow in a defined medium containing bovine serum albumin as the sole carbon/energy source. These results indicate that the proteolytic activity of P. gingivalis toward bovine serum albumin and gelatin derived from human type I collagen appears to be attributable to RGP and KGP. The hemagglutinin gene hagA of P. gingivalis possesses the adhesin domain regions responsible for hemagglutination and hemoglobin binding that are also located in the C-terminal regions of rgpA and kgp. A rgpA kgp hagA triple mutant constructed in this study exhibited no hemagglutination using sheep erythrocytes or hemoglobin binding activity, as determined by a solid-phase binding assay with horseradish peroxidase-conjugated human hemoglobin, indicating that the adhesin domains seem to be particularly important for P. gingivalis cells to agglutinate erythrocytes and bind hemoglobin, leading to heme acquisition.

Adhesins, Bacterial↗

Interaction of blood with enterobacteriaceae: hemolysis, hemagglutination, fibrinolysis.

One thousand eighty enterobacteriaceae, isolated during a period of three months, were tested for the presence of hemolysis, hemagglutination and fibrinolysis on human erythrocytes and plasma. The fibrinolysis on human erythrocytes and plasma. The Escherichia coli have the greatest diversity of action on the blood. Of 481 strains, 32.9% were hemolytic, 21.9% fibrinolytic, and 10.5% hemagglutinating. Of 190 strains of Klebsiella, 95.2% were fibrinolytic. Of 53 strains of Enterobacter, 90.6% were fibrinolytic, and of 53 strains of Enterobacter hafniae, 66% were fibrinolytic. Of seven strains of Serratia, 28.5% were hemolytic and 14.3% fibrinolytic. The Proteae were mostly fibrinolytic: 60.5% of 141 strains, with three strains being hemolytic and fibrinolytic. Of 19 strains of Citrobacter, 52.6% were fibrinolytic only. Providenica, Salmonella and Shigella did not interact with human blood. The patterns of blood interactions with the different species of Enterobacteriaceae are of value in the evaluation of the pathogenesis of the infections and septicemias they cause. Their study is an essential step in the understanding of the sequence of events leading to severe disturbances of the blood-clotting mechanism.

Enterobacteriaceae↗

Hemagglutination tests for syphilis antibody.

In a study of serodiagnosis of syphilis, the authors compared the specificities and sensitivities of two hemagglutination tests, a sheep-erythrocyte test (MHA-TP) and a trukey-erythrocyte test (TPHA), with those of the Fluorescent Treponemal Antibody-Absorption (FTA-ABS) test. In tests of sera from 935 patients without syphilis, the MHA-TP, TPHA, and FTA-ABS tests were reactive for 0.96, 0, and 1.3% respectively. The false-positive results were usually transient and not associated with underlying illness. For the 68 patients with syphilis, the MHA-TP test was as sensitive as the FTA-ABS test in all stages except untreated primary disease. The TPHA test appeared to be undersensitive, and testing of follow-up sera from persons with latent syphilis showed unexplained conversion of false-negative TPHA results to reactive results. Reproducibilities of the two hemagglutination tests were comparable. The MHA-TP test is a valuable confirmatory test for syphilis. Further study is needed before the use of the TPHA test can be recommended.

Animals↗

Simple method for quantitation of cell-bound protein A on Staphylococcus aureus cells by means of hemagglutination with sheep erythrocytes differentially sensitized with rabbit antibody and its clinical application.

A simple method for quantitation of cell-bound protein A (SpA) on organisms of Staphylococcus aureus was successfully devised by using hemagglutination between staphylococcal organisms and a series of sheep erythrocyte suspensions sensitized with different amounts of anti sheep erythrocyte rabbit antiserum. The validity of the principle and the reproducibility of the method presented here were precisely analyzed and the details of the method are presented. The hemagglutination was quantitatively inhibited both by normal rabbit serum and by soluble SpA. Using the method presented here, 376 strains of S. aureus freshly isolated from clinical materials were subjected to SpA quantitation in cell-bound form. According to the results, there was an unexpected distribution profile in the amounts of cell-bound SpA among the clinical isolates, which showed a two-peak pattern. A possible usefulness of the method presented here in clinical investigations is briefly discussed also.

Animals↗

Fimbriation, hemagglutination and adherence properties of fresh clinical isolates of Branhamella catarrhalis.

This study investigated the fimbriation on 24 fresh clinical isolates of Branhamella catarrhalis by electron microscopy. All the strains were isolated from patients with respiratory infections. The Branhamella catarrhalis strains were classified into three groups according to the grade of fimbriation. Among these 24 strains the incidence of densely fimbriated, moderately fimbriated and sparsely fimbriated isolates were 12 (50%), 7 (29%) and 5 (21%), respectively. After five-times serial subculture on Brain Heart Infusion agar, the average number of fimbriae per bacteria was decreased from 174 to 114 in the densely fimbriated strain and from 48 to 10 in the moderately fimbriated strain. Moreover, 20% of the population became non-fimbriated in moderately fimbriated strain after the serial subculture. In strains with higher hemagglutination titer the number of fimbriae was significantly (P < 0.04) more than in strains with lower hemagglutination titer.

Bacterial Adhesion↗

The hemagglutinating action of Vibrio vulnificus metalloprotease.

Vibrio vulnificus protease (VVP), a 45-kDa zinc metalloprotease, consists of two functional domains: an N-terminal 35-kDa polypeptide having endoproteinase activity, and a C-terminal 10-kDa polypeptide that mediates the binding of VVP to the erythrocyte membrane. Therefore, VVP, but not its N-terminal endoproteinase domain alone, has agglutinating activity to rabbit erythrocytes. When a single zinc atom in the catalytic center was substituted by treatment with CuCl2 or NiCl2, proteolytic and hemagglutinating activities were reduced by Ni substitution but not by Cu substitution. Cu-treated 35-kDa polypeptide showed sufficient affinity of the catalytic center and weak binding ability to the erythrocyte membrane, but the Ni-treated polypeptide did not. These results suggest that the binding of endoproteinase domain to membrane is also necessary for hemagglutination.

Animals↗

Surface appendages, hemagglutination, and adherence to human epithelial cells of Bacteroides intermedius.

Four types of morphologically distinct surface appendages were found on oral strains of Bacteroides intermedius. These appendages, designated as A, B, C, and D, were different in size, with diameters of 1-2 nm, 12 nm, 8 nm, and 5 nm, respectively. Twenty different strains were examined by electron microscopy and 5 strains, 5, 17, 27, 113, and 25611, were selected to be representative of the different appendages encountered. Type A appendages were thin filaments peritrichously arranged on the cell surface and were associated mainly with Strains 5, 113, and ATCC 25611. Type B appendages were present on all 5 strains but these structures were scarce (i.e., less than or equal to 3 per organism). Type C appendages were associated exclusively with Strain 17. Type D appendages were present mainly on Strain 27. Hemagglutination activity of these organisms and their ability to adhere to human buccal epithelial cells were also tested. Strain 17, which possessed Type C appendage (uncommon to the other strains), agglutinated strongly with 5 different species of erythrocytes and adhered avidly to human buccal epithelial cells. The other strains, possessing different types of appendages, showed considerable variation in hemagglutination activity and adherence properties. Correlation between these surface appendages and adherent functions was speculated.

Animals↗