Truncated surface protective antigen (SpaA) of Erysipelothrix rhusiopathiae serotype 1a elicits protection against challenge with serotypes 1a and 2b in pigs.
Erysipelothrix rhusiopathiae is a causal agent of swine erysipelas, which is of economic importance in the swine industry by virtue of causing acute septicemia, chronic arthritis, and endocarditis. However, little is known about the genetic properties of its protective antigens. Recently, a surface protective antigen (SpaA) gene was identified from serotype 2 in a mouse model. We cloned spaA from virulent strain Fujisawa (serotype 1a) and determined that the N-terminal 342 amino acids without C-terminal repeats of 20 amino acids have the ability to elicit protection in mice. Fusions of 342 amino acids of Fujisawa SpaA and histidine hexamer (HisSpa1.0) protected pigs against challenge with both serotype 1 and serotype 2, the most important serotypes in the swine industry. Pigs immunized with HisSpa1.0 reacted well with both HisSpa1.0 and intact SpaA by enzyme-linked immunosorbent assay and immunoblotting. Serum collected at the time of challenge from a pig immunized with HisSpa1. 0 markedly enhanced the in vitro phagocytic and killing activity of pig neutrophils against the bacteria. DNA sequences of protective regions of spaA genes from five strains of serotypes 1 and 2 were almost identical. The full DNA sequences also seemed to be conserved among strains of all 12 serotype reference strains harboring the spaA gene by restriction fragment length polymorphism analysis of PCR products. These results indicates that SpaA is a common protective antigen of serotypes 1 and 2 of E. rhusiopathiae in swine and will be a useful tool for development of new types of vaccines and diagnostic tools for effective control of the disease. (+info)
Erysipelothrix rhusiopathiae: bacteriology, epidemiology and clinical manifestations of an occupational pathogen.
Erysipelothrix rhusiopathiae has been recognised as a cause of infection in animals and man since the late 1880s. It is the aetiological agent of swine erysipelas, and also causes economically important diseases in turkeys, chickens, ducks and emus, and other farmed animals such as sheep. The organism has the ability to persist for long periods in the environment and survive in marine locations. Infection in man is occupationally related, occurring principally as a result of contact with animals, their products or wastes. Human infection can take one of three forms: a mild cutaneous infection known as erysipeloid, a diffuse cutaneous form and a serious although rare systemic complication with septicaemia and endocarditis. While it has been suggested that the incidence of human infection could be declining because of technological advances in animal industries, infection still occurs in specific environments. Furthermore, infection by the organism may be under-diagnosed because of the resemblance it bears to other infections and the problems that may be encountered in isolation and identification. Diagnosis of erysipeloid can be difficult if not recognised clinically, as culture is lengthy and the organism resides deep in the skin. There have been recent advances in molecular approaches to diagnosis and in understanding of Erysipelothrix taxonomy and pathogenesis. Two PCR assays have been described for the diagnosis of swine erysipelas, one of which has been applied successfully to human samples. Treatment by oral and intramuscular penicillin is effective. However, containment and control procedures are far more effective ways to reduce infection in both man and animals. (+info)
Serotyping and pathogenicity of Erysipelothrix strains isolated from tonsils of slaughter pigs in Thailand.
Erysipelothrix strains were isolated from the tonsils of 46 (15.0%) of 307 apparently healthy slaughter pigs in Thailand during the period of August to September, 1997. A total of 27 of the 46 Erysipelothrix isolates could be classified into 5 serovars but the remaining 19 were untypable in this study. Of the 25 isolates serologically identified as Erysipelothrix rhusiopathiae, 20, 4, and 1 isolates belonged to serovars 2, 12, and 17, respectively. Only 2 isolates from the tonsils belonged to Erysipelothrix tonsillarum and represented either serovar 7 or 10. Although the periods and the districts of the survey were limited, the information obtained in the present investigation demonstrates the presence of a variety of serovars in pigs in Thailand. Of 29 selected isolates belonging to serovars 2, 7, 10, 12, 17, and untypable, only 5 (17.2%) were virulent for both mice and pigs. Five of these virulent isolates belonging to serovars 2 and 12 killed less than 30% of mice immunized with a swine erysipelas bacterin commercially available in Thailand, suggesting that the vaccine elicited a sufficient immunity to these field isolates. (+info)
Direct and rapid detection by PCR of Erysipelothrix sp. DNAs prepared from bacterial strains and animal tissues.
A PCR method for rapid screening of Erysipelothrix spp. in the slaughterhouse was carried out by using four species-specific sets of oligonucleotide primers after initial amplification with the primer set MO101-MO102, which amplifies the 16S rRNA sequences of all four Erysipelothrix species. The DNA sequences coding for the rRNA gene cluster, including 16S rRNA, 23S rRNA, and the noncoding region downstream of 5S rRNA, were determined in order to design primers for the species-specific PCR detection system. The homology among the 4.5-kb DNA sequences of the rRNA genes of Erysipelothrix rhusiopathiae serovar 2 (DNA Data Bank of Japan accession no. AB019247), E. tonsillarum serovar 7 (accession no. AB019248), E. rhusiopathiae serovar 13 (accession no. AB019249), and E. rhusiopathiae serovar 18 (accession no. AB019250) ranged from 96.0 to 98.4%. The PCR amplifications were specific and were able to distinguish the DNAs from each of the four Erysipelothrix species. The results of PCR tests performed directly with tissue specimens from diseased animals were compared with the results of cultivation tests, and the PCR tests were completed within 5 h. The test with this species-specific system based on PCR amplification with the DNA sequences coding for the rRNA gene cluster was an accurate, easy-to-read screening method for rapid diagnosis of Erysipelothrix sp. infection in the slaughterhouse. (+info)
Potential errors in recognition of Erysipelothrix rhusiopathiae.
Here we describe four isolations of Erysipelothrix rhusiopathiae associated with polyarthralgia and renal failure, septic arthritis, classic erysipeloid, and peritonitis. Although the biochemical identification was straightforward in each case, recognition presented a challenge to the clinical microbiologist, since in three cases E. rhusiopathiae was not initially considered due to unusual clinical presentations, in two cases the significance might not have been appreciated because growth was in broth only, and in one case the infection was thought to be polymicrobic. Because the Gram stain can be confusing, abbreviated identification schemes that do not include testing for H(2)S production could allow E. rhusiopathiae isolates to be misidentified as Lactobacillus spp. or Enterococcus spp. in atypical infections. (+info)
Quantitative diversity of 67 kda protective antigen among serovar 2 strains of Erysipelothrix rhusiopathiae and its implication in protective immune response.
Mouse monoclonal antibodies (MAbs), raised against the NaOH-extracted antigen of Erysipelothrix rhusiopathiae strain Kyoto (serovar 2), recognized two different epitopes on a single protein of molecular weight 67 kDa. The MAbs were classified as protective or non-protective against strain Fujisawa (serovar 1). In immunoblotting analysis using the MAbs, fifteen wild strains were shown to contain different amounts of 67 kDa protective antigen. Each formalin-killed whole cell vaccine (bacterin) prepared from the fifteen wild strains conferred different levels of protection against strain Fujisawa in mice. Bacterins prepared from wild strains with larger amounts of 67 kDa protective antigen tended to give high levels of antigen-specific antibody and better protection to mice. These results indicate that the amount of 67 kDa protective antigen which influences the induction of protective immune responses may vary substantially among the strains of E. rhusiopathiae (serovar 2). (+info)
Distribution of antibody against Erysipelothrix rhusiopathiae in cattle.
Serum samples collected from 854 cattle in nine prefectures of Japan, from Hokkaido to Okinawa, between 1988 and 1992 were examined for presence of antibodies against Erysipelothrix rhusiopathiae by growth agglutination test. Most of the sera showed positive reactions, and the antibody titers ranged from below 4 to above 128. Seventy-six percent of the sera showed titers of 32 or above, and 34% showed titers of 128 or above. The titers had a tendency to be higher in the south and lower in the north and were clearly low in sera from areas with no swine industry. These results indicated that Japanese cattle had been infected with E. rhusiopathiae and that clinical cases of the disease were possible. (+info)
Pulsed-field gel electrophoresis in differentiation of erysipelothrix species strains.
We report here the first analysis of Erysipelothrix spp. using pulsed-field gel electrophoresis (PFGE). Seventy strains of Erysipelothrix spp. were analyzed. SmaI, AscI, and NotI were tested for the ability to cleave the DNA extracted from those strains, and among them, SmaI was the most reliable enzyme. Sixty-three distinct PFGE patterns were produced, and no DNA degradation was observed, allowing the identification of all of the strains. Based on these results and on those of a previous analysis using randomly amplified polymorphic DNA and ribotyping, PFGE with SmaI might be considered to be more sensitive than those methods and to be the best method for epidemiological studies of strains of this genus. (+info)