Evaluation of microagglutination test for differentiation between Serpulina (Treponema) hyodysenteriae and S. innocens and serotyping of S. hyodysenteriae

Abstract

Swine dysentery is a mucohemorrhagic diarrheal disease caused by the anaerobic spirochete Serpulina hyodysenteriae. At present, the serotyping is done by immunodiffusion testing with lipopolysaccharide (LPS) extract as antigen and rabbit hyperimmune sera produced against different serotypes of S. hyodysenteriae. Since the preparation of LPS is time-consuming and requires a large quantity of bacteria, it is desirable to use a serotyping method which does not require the extraction of LPS. In the present investigation, microagglutination was evaluated by using both formalinized wholeand boiled-cell suspensions as antigens and rabbit hyperimmune sera produced against formalinized whole-cell suspensions of reference strains of S. hyodysenteriae and S. innocens B256. Use of boiled cell suspension as antigen permitted the differentiation between isolates of S. hyodysenteriae and S. innocens as well as serotyping of S. hyodysenteriae strains accurately. A total of 18 isolates were identified as S. hyodysenteriae, and 3 isolates were identified as S. innocens. The microagglutination test was found specific, sensitive, and easy to perform; thus, it was judged suitable for routine identification and serotyping of S. hyodysenteriae isolates.

A reverse vaccinology approach to swine dysentery vaccine development

“…Normal mouse serum and serum from a pig hyperimmunized with B. hyodysenteriae B78 T bacterin were used as the negative and positive controls respectively. The agglutination test was performed in 96 well U-bottom plates with 5 × 10 9 cells of B. hyodysenteriae strain WA1 resuspended in 50 μl PBS, carried out essentially as previously described (Diarra et al, 1994). Antiserum was serially diluted in 50 μl PBS (1:100 to 1: 6800) and added to each well containing spirochaetes.…”

Production and characterization of monoclonal antibodies against Serpulina hyodysenteriae and S. innocens and their use in serotyping

“…Each procedure has merits, but none has been free from problems mainly due to extensive cross-reactions among different serotypes. Although a microplate agglutination test with a boiledcell (BC) suspension was an improvement over other serological methods for serotyping S. hyodysenteriae, the problem of cross-reactivity still remained even after the antigens of some of the field strains were boiled (8). The aim of this study was to produce and characterize monoclonal antibodies (MAbs) directed against type-specific epitopes of S. hyodysenteriae and S. innocens with the aim of determining a more accurate serological classification of porcine Serpulina spp.…”

“…S. hyodysenteriae was harvested from blood agar plates and washed twice in phosphate-buffered saline (PBS) (0.001 M, pH 7) by centrifugation at 800 ϫ g for 10 min. Whole-cell (WC) and BC suspensions were prepared by the methods of Diarra et al (8). LPS was prepared by the method of Baum and Joens (5).…”

“…Studies on the epidemiology of swine dysentery have been hampered by a lack of suitable serotyping methods. So far, several serological tests have been used for serotyping S. hyodysenteriae (5,8,10,21). The major drawback of the currently used serological tests is the existence of extensive crossreactions among different serotypes.…”