Antibodies, directed towards Campylobacter jejuni antigens, in sera from poultry abattoir workers

Abstract

Occupational exposure of susceptible humans to Campylobacter jejuni appears to result in resistance to disease. This is believed to be due to acquired protective immunity. To support this hypothesis the levels of C. jejuni-specific IgG and IgM antibodies were determined in sera from poultry abattoir workers. Such individuals are persistently exposed to C. jejuni, but apparently rarely acquire campylobacteriosis. Sera from 43 short-term workers (employed < or = 1 month), 78 long-term workers and 40 blood donors were investigated by ELISA. In 51 individuals a second serum sample, taken at least 1 month after the first, was also investigated. Eight workers had C. jejuni-positive faecal cultures and only one, a short-term worker, had symptoms of campylobacteriosis. There were significantly higher levels of specific IgG antibodies in long-term workers than in either of the other groups. There was no significant difference detectable in specific IgM antibody levels between any of the groups. The results provide supporting evidence that long-term exposure to C. jejuni induces circulating antibodies which reflect apparent reduced susceptibility to disease. Western blotting showed flagellin and polypeptides of 45, 40, 32 and 30 kD bound antibodies significantly more frequently by sera from long-term workers than short-term workers and blood donors. The most commonly detected antigens were the 40-kD (80%) and flagellin (55%). The results indicate that specific serum IgG responses induced by endemic exposure to C. jejuni might be directed towards a small number of protein antigens with apparently conserved epitopes.

Fig. 1

Scatter plot showing ELISA results (OD450) indicating the range of IgG antibody levels within and between the three groups sampled.

Fig. 2

Western blot of the specificity of the total serum antibodies towards the total proteins of Campylobacter jejuni 81116 separated by SDS–PAGE. Fifteen sera were selected, from each group of random blood-donors (D), short-term (S) and long-term (L) abattoir workers, to demonstrate the variability in antibody response. Campylobacter jejuni flagellin (F) was located using a monoclonal anti-flagellin antibody (strip 16). The location of the 40-kD polypeptide is shown (>). The molecular mass standards are indicated in kD.