Detection of Mycoplasma gallisepticum by direct immunofluorescence using a species-specific monoclonal antibody

A monoclonal antibody against Mycoplasma gallisepticum (MG) (strain S6) was prepared in mice and identified as isotype IgG1 by standard procedures. Although it did react at high titers (1:100,000) in the enzyme-linked immunosorbent assay (the original method for its identification), it failed to react in the agglutination, hemagglutination-inhibition, and growth-inhibition tests. When conjugated to fluorescein isothiocyanate, the monoclonal antibody reacted with the homologous and eight "atypical" strains of MG but not with M. meleagridis or M. synoviae in the direct fluorescent-antibody test. This reagent may be useful for detecting field infections involving atypical strains of MG.     

Antigenic variation of Mycoplasma gallisepticum, as detected by use of monoclonal antibodies.

A panel of monoclonal antibodies (MAb) developed against Mycoplasma gallisepticum strain PG31 was used to probe the antigenic profiles of 5 recognized strains (PG31, R, S6, F, A5969) and 6 field isolates of M gallisepticum. Monoclonal antibody G9 predominantly recognized antigens at apparent molecular mass positions of 90 to 98 kDA. The MAb reacted with all strains and isolates, but the molecular mass position of the antigens varied among some mycoplasmas. Monoclonal antibody G12 reacted with all strains and isolates of M gallisepticum and had an identical banding pattern. However, MAb G10 and G11 reacted selectively only with a limited number of strains and/or isolates. Surface distribution of the MAb-recognized antigens was revealed by immunoelectron microscopy. Partial physicochemical characterization of MAb G9-recognized antigens identified glycopeptide characteristics. Monoclonal antibody G9 reacted with surface antigens and, hence, participated in agglutination of M gallisepticum. However, the degree of agglutination varied among the various strains and isolates, indicating a quantitative or conformational limitation or an alteration in the anomeric expression of the epitopes. Antigenic variation in M gallisepticum may be mediated by immunologic selective pressures, or a proclivity for habit niche in the host.     

Detection of Mycoplasma gallisepticum and Mycoplasma synoviae antibodies in the sera of indigenous chickens by rapid serum agglutination test at Mmopane, Gaborone, Botswana

The mean flock size was ten chickens per rural farmer. Antibodies to Mycoplasma gallisepticum and Mycoplasma synoviae were detected in 57.88% and 67.33% of the chicken sera respectively.     

Serotyping of Haemophilus pleuropneumoniae by rapid slide agglutination and indirect fluorescent antibody tests in swine

One hundred and forty-one isolates of Haemophilus pleuropneumoniae from Iowa and Illinois swine were characterized morphologically and biochemically and serotyped by rapid slide agglutination (RSA) and indirect fluorescent antibody (IFA) tests. Hyperimmune antisera were produced in rabbits using inactivated whole-cell suspensions of the reference strains for H pleuropneumoniae serotypes 1 to 7 and strain 202, representing the taxon "minor group." Cross testing of the reference strains and reference antisera indicated the antisera to be essentially serotype-specific, although reactivity of some antisera with heterologous strains was observed. Cultures of the 141 isolates formed adherent or smooth colonies or mixtures of these colony forms. Adherent and smooth colony types were found in all serotypes identified. Microscopic and biochemical characteristics of all isolates were typical of those previously described for H pleuropneumoniae. The overall incidence of H pleuropneumoniae serotypes was serotype 5, 55.3%; serotype 1, 34.0%; serotype 7, 7.8%; and nontypeable, 2.8%. Comparing the 2 test procedures, 87.2% of the isolates could be typed by RSA, and 66.0% could be typed by IFA. Cross-reactions between serotype 4 antisera and serotype 5 and 7 isolates were common with the IFA test. The reactions with serotype 7, but not serotype 5, were eliminated by cross adsorption of serotype 4 antisera. There was good correlation between the 2 test procedures, but RSA was judged to be more specific and sensitive than IFA.     

Identification of Mycoplasma gallisepticum and M. synoviae by flow cytometry

Immunofluorescence and flow cytometric methods were examined to detect and distinguish Mycoplasma gallisepticum and M. synoviae. The procedure employed 24-hr broth cultures of each organism, direct immunofluorescence staining with either homologous or heterologous antiserum, and analyses by flow cytometry. The organisms were distinguishable on the basis of fluorescent profiles when stained with the appropriate antiserum.     

Hemagglutination-inhibition versus serum plate agglutination in detecting Mycoplasma gallisepticum in broiler flocks.

Sera from 43,040 broilers in 36 flocks were tested for antibodies to Mycoplasma gallisepticum by serum plate agglutination (SPA) and hemagglutination-inhibition (HI) tests. The importance of testing SPA-negative samples for HI antibodies was demonstrated.     

An adhesion-hemadsorption inhibition test for the detection of serum antibody to Mycoplasma gallisepticum

A simple adhesion-hemadsorption inhibition (AHAI) test was developed for the detection of antibodies to Mycoplasma gallisepticum in the chicken sera. The AHAI antibody was detected simultaneously with HI antibody from sera of chickens intratracheally inoculated with viable cells of M. gallisepticum. A good correlation between HI and AHAI antibody titers was obtained with 382 (84.7%) of 451 sera from chickens reared on farms spontaneously contaminated with M. gallisepticum, whereas the remainder, 69 sera, was positive for HI but negative for AHAI test. It was not apparent whether the latters exhibited a non-specific reaction or the discrepancy was due to the lower sensitivity of AHAI reaction. The AHAI test does not require a great amount of antigen, special reagents or instruments, or pre-absorption treatment of test sera, and, therefore, it may serve as a simple serological test for detecting antibodies to M. gallisepticum.     

A slide latex agglutination test for the rapid detection of antibodies in serum against porcine parvovirus

A slide latex agglutination test (LAT) was developed and evaluated to detect serum antibodies against porcine parvovirus. Porcine parvovirus antigen was obtained by 10% PEG-6000 and 0.5 mol/l sodium chloride precipitation, and inactivated by 0.1% methanal. Two per cent suspensions of latex particles (0.5-0.8 microm) were coated by adding an equal volume of porcine parvovirus antigen at 0.34 microg/ml. Repeatability of latex agglutination test was evaluated with a panel of 100 sera using the same and different antigen lots. A good agreement between LAT and haemagglutination inhibit assay was observed. Because of convenience and speed of performance, this method would be used widely in clinic examination.     

鸡毒支原体烯醇化酶单克隆抗体研制及黏附阻断

通过对鸡毒支原体烯醇化酶的克隆和原核表达,利用表达产物免疫小鼠,制备单克隆抗体,以超声波裂解的MG全菌作为筛选抗原,结果获得了6株特异性单抗,分别命名为：1A4、2D7、2E4、2F4、384和3D8。经间接ELISA、免疫荧光试验及Western blot检测发现：1A4具有荧光效价和高滴度的ELISA效价,但无免疫印迹效价;而其他5株单抗,免疫印迹呈阳性,但无表面染色的活细胞免疫荧光。在所有6株单抗中,仅1A4单抗有MG细胞黏附抑制作用,可导致MG的黏附率降低34．40％,而且1A4与其他5种单抗混合后,则黏附率可下降57．69％。这些抗体的制备将为烯醇化酶生物学活性研究奠定基础。     

6种常用抗菌药物对鸡毒支原体的药物敏感性试验

鸡毒支原体(MG)是一种严重危害养禽业的病原体,可引起鸡的慢性呼吸道病(CRD),其特征性症状是呼吸啰音、咳嗽、气管炎、气囊炎、流眼泪等[1].     

Evaluation of three slide agglutination tests for rapid identification of Staphylococcus aureus.

Three slide agglutination tests for identification of Staphylococcus aureus were compared. The agglutination tests used for evaluation were Staphaurex (Wellcome Diagnostics), Staphyslide-Test (BioMerieux), and ANI S. aureus TEST (Ani Biotech Oy). A total of 347 isolates were analyzed, including 288 strains of S. aureus, 49 of S. epidermis, 11 of S. intermedius, 12 strains of other staphylococci and 14 non-staphylococcal strains. One hundred of the S. aureus strains were isolates from cases of food poisoning, 129 from mastitis and 59 from other clinical cases. The sensitivities of the tests were also compared using diluted suspensions of S. aureus strains and with purified Protein A dilutions. The results showed that the sensitivities of the tests were 98.6%, 97.9% and 99.0% for Staphaurex, Staphyslide-test and ANI S. aureus TEST, respectively. The specificities were 100% for the Staphyslide test and 98.8% for both the ANI S. aureus TEST and the Staphaurex test. The sensitivities measured with diluted S. aureus strain suspensions and Protein A solutions were equal with the Staphaurex and ANI S. aureus TEST. All the agglutination tests studied proved to be practical, easy to use and accurate for the rapid identification of S. aureus strains from culture isolates.     

Haemadsorption inhibition test for the identification of Mycoplasma gallisepticum and Mycoplasma synoviae

Summary

Colonies of the avian mycoplasma strains Mycoplasma gallisepticum S6 and Mycoplasma synoviae WVU 1853 and two Mycoplasma synoviae isolates from this laboratory were shown to be haemadsorption positive for chicken erythrocytes. Three Mycoplasma synoviae isolates from this laboratory proved to be haemadsorption and haemagglutination negative. The haemadsorption of the mycoplasma colonies mentioned above was inhibited with specific antisera of either high or low titre. No cross‐inhibition was observed. It is suggested that this test could be used for a quick tentative identification of the two avian mycoplasmas on primary solid‐medium cultures.     

Identification of species-specific and interspecies-specific polypeptides of Mycoplasma gallisepticum and Mycoplasma synoviae

Temporal antisera (TA) prepared in susceptible Leg-horn-type chickens against Mycoplasma gallisepticum and M synoviae were evaluated to determine the extent of cross-reactivity in ELISA and hemagglutination inhibition tests. Species-specific and interspecies-specific polypeptides were identified after electrophoretic separation and protein immunoblotting with reference antisera, TA, and a monoclonal antibody specific for M gallisepticum. Mycoplasma gallisepticum antiserum cross-reacted with M synoviae polypeptides in ELISA and TA immunoblots. Two major M synoviae polypeptides (88 and 53 kilodaltons [kD]) cross-reacted with M gallisepticum antisera in TA immunoblots. An M gallisepticum polypeptide of 70 kD cross-reacted with M synoviae in TA immunoblots. In contrast, M gallisepticum and M synoviae reference antisera cross-reacted when immunoblotted with heterologous antigens. A monoclonal antibody specific for M gallisepticum bound to a 69-kD polypeptide in lectin-purified and whole-cell M gallisepticum protein fractions in immunoblot assays. The lectin-purified fraction hemagglutinated chicken RBC. Seemingly, the 69-kD polypeptide may constitute all or part of the M gallisepticum hemagglutinin.