The importance of enterotoxigenic Escherichia coli containing the 987P antigen in causing neonatal colibacillosis in piglets in Indonesia.

A survey was undertaken in piggeries in the Bogor and Jakarta Capital Territory areas to identify the antigens associated with enterotoxigenic Escherichia coli (E. coli). Rectal swab samples were collected from 65 normal piglets and from 858 with diarrhoea. Fimbrial and O-antigens were determined by agglutination tests. The 987P antigen was only associated with non-haemolygic E. coli in colonies grown for 3-10 days in tryptic soy broth. Organisms which possessed 987P antigen were isolated from 56.4% of piglets with diarrhoea and from 10.8% of normal piglets. Most cases of diarrhoea that were associated with E. coli 987P occurred within the first 3 weeks of life. Multiple infections occurred in 13.4% of cases and were associated with E. coli K88 in eight cases (1.7%) K99 in 26 cases (5.4%) and F41 in 31 cases (6.4%). Of 959 isolates of E. coli 987P, 80.7% were O-group 20, 13% were O-group 9 and 0.5% were O-group 141 with 5.7% being non-typable. Heat stable toxin was produced by all five E. coli 987P isolates tested.

Rapid identification of Pasteurella multocida organisms responsible for haemorrhagic septicaemia using an enzyme-linked immunosorbent assay.

Haemorrhagic septicaemia (HS) is caused by specific serotypes of Pasteurella multocida and is one of the major economic diseases of cattle and buffalo in South East Asia. Definitive diagnosis of the disease-causing organism with the available methods is labour intensive and not totally reliable, consequently, an ELISA system to identify P multocida organisms which cause HS was developed. One hundred and twenty-four P multocida isolates were tested, 58 were type strains and 66 were field isolates. Analysis of these strains indicated the assay had a specificity of 99 per cent and sensitivity of at least 86 per cent. The sensitivity could be an underestimate, as five isolates assumed to be false negative reactions may not all be HS-causing strains. The HS ELISA provides a rapid, simple, accurate and inexpensive diagnostic assay for identification of HS causing organisms but does not represent a new typing system for P multocida. This assay will also enable countries to assess the impact of HS more accurately.

Evaluation of bovine antibody responses to haemorrhagic septicaemia vaccine.

ELISA and immunoblotting techniques were used to examine the humoral immune response to Pasteurella multocida, in bovine sera from Indonesia and Malaysia. Elevated levels of antibody to a crude lipopolysaccharide preparation were found in vaccinated animals. In addition to the response to lipopolysaccharide, antibodies from the vaccinated cattle strongly labelled five to six of the 40 protein bands in this organism.

A urease-ELISA for the detection of mycoplasma infections in poultry.

An ELISA utilising a urease-antibody conjugate specific to chicken IgG was examined as an alternative to the serum agglutination and the haemagglutination inhibition tests in the diagnosis of Mycoplasma gallisepticum and M. synoviae infections in poultry. Use of a urease conjugate allowed the serum reactions to be appraised without the need for expensive photometric equipment. Non-specific binding of conjugate to antigen was eliminated by treatment of antigen coated microplates with 10% foetal calf serum in phosphate buffered saline. Some chicken serums produced non-specific reactions. These reactions were reduced without any loss of test sensitivity by making the initial 1:5 dilution of chicken serum in whole sheep serum rather than diluting buffer. Tests on serums from experimentally infected chickens showed that the urease ELISA was specific, and was as sensitive as the serum agglutination test but more sensitive than the haemagglutination inhibition test.