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Ten Campylobacter jejuni isolates, 8 identified as C. jejuni biotype II of Lior and 2 as C. jejuni biotipe I, were recovered from aborted pig fetuses. In order to discriminate among strains, restriction fragment length polymorphism (RFLP) using Ddel of polymerase chain reaction (PCR) products of flaA gen was used. C. jejuni biotype II strains could be diferenciated in 6 by PCR-RFLP, and one subtype was obtained from C. jejunibiotype I. Although there is great variability of molecular techniques applied to the Campylobacter epidemiological studies, PCR-RFLP demonstrated to be a simple and accessible technique to discriminate Campylobacter jejuni isolates.

Campylobacter jejuni and Campylobacter coli were isolated from aborted pig fetuses which proceeded from different animals and farms between February 2000 and March 2001. Seven Campylobacter jejuni biotype II, three biotype I and one Campylobacter coli biotype I were identified by phenotypic tests and Lior's scheme. To corroborate and compare the phenotypic results, 7.5, 10 and 12.5% polyacrilamide gel electrophoresis (SDS-PAGE) were used under reducing conditions. Characteristic bands of hypervariable dense zone within C. jejuni and C. coli species were observed in all the whole cell protein extracts with differences in mobility. It was possible to establish differences between identical phenotypic Campylobacter isolates and different protein profile from fetuses of the same litter. SDS-PAGE is a stable and reproducible method to establish differences between Campylobacter strains and is considered applicable for the differentiation of the wide variability of Campylobacter species for epidemiologic purposes.

An indirect enzyme linked immunosorbent assay was developed. Infected and non infected allantoic fluids precipitated with polyetilenglycol 6000 were used as antigen and control antigen, respectively. Serum samples were diluted 1/20 and a commercial horse radish peroxidase-labelled rabbit anti-equine IgG was used as second antibody. The reaction was developed using azino-diethylbenzotyazol-sulfonate (ABTS). Cut-off was determined by ratio sample (Rs). The hemagglutination inhibition test was used as a reference test for the 391 samples analyzed. Of these, 301 sera were positive by hemagglutination inhibition test and indirect ELISA, 75 were negative by both techniques, and 15 were positive by indirect ELISA and negative by hemagglutination inhibition test. Using hemagglutination inhibition test as standard, the indirect ELISA showed a relative specificity and sensitivity of 83.3 and 100%, respectively. This indirect ELISA is useful as screening test.