Comparison of the haemagglutination inhibition test and the serum neutralisation test in tracheal organ cultures for typing infectious bronchitis virus strains

Abstract

SUMMARYFive strains of infectious bronchitis (IB) virus, which had been compared antigenically by the serum neutralisation (SN) test in tracheal organ cultures (OC), were arbitarily coded and then compared by the haemagglutination inhibition (HI) test. Their antigenic relationships were found to be similar by the two methods but, because of the high and variable cross reactions found in the HI test, the differences between the strains were less clear by that method. It was concluded that the HI test, in its present state of development, is considerably less type-specific than the SN test in OC, and cannot be recommended for defining antigenic relationships between strains of IB virus. However, it retains its value for diagnosing IB or for monitoring the vaccinal status of flocks. INTRODUCTIONThe lack of a reliable but simple type classification system for infectious bronchitis (IB) virus continues to give rise to practical problems and to confusion. Since the haemagglutination inhibition (HI) test for IB was first suggested by Bingham et al. (1975) and developed by Alexander et al. (1976) and Alexander and Chettle (1977), it has been used widely for monitoring serological responses to IB vaccination and for the diagnosis of IB infections. Lashgari and Newman (1984) used it to compare seven reference strains of IB virus and found that although they were antigenically distinct, complex relationships existed between them. Brown and Bracewell (1985) found that the HI test could be used to type IB virus strains, provided that the test was carried out under carefully controlled conditions and that all virus strains were tested against antiserum prepared against each strain.

A monoclonal antibody‐based antigen capture enzyme‐linked immunosorbent assay for identification of infectious bronchitis virus serotypes

“…This cross-reactivity of chicken serum stems from the fact that many epitopes on the IBV structural proteins (with the exception of the serotype-specific epitopes on the SI protein) are shared by different serotypes (Koch, et al, 1986;Niesters et al, 1987;Ignjatovic & McWaters, 1991;Karaca et al, 1992). Therefore, IBV antibodies induced by exposure to one serotype tend to cross-react with other IBV serotypes in most assays except the VN test (Lucio & Hitchner 1970;Hopkins, 1974;Johnson & Marquardt 1975;Marquardt et al, 1981;Cook et al, 1987;. The C-ELJSA described here circumvents the cross reactivity problem associated with chicken sera.…”

Detection of infectious bronchitis virus

“…Brown & Bracewell (1985) found high cross-reactions between serotypes in the HI test. Cook et al (1987) showed that the antigenic relationships of strains when serotyping by VNT (using TOCs) and HI test was similar but, because of the high and variable cross-reactions found in the HI test, the differences between the strains were less clear in the HI test.…”

“…There are several reports on serotyping by the HI test (Lashgari & Newman, 1984;Brown & Bracewell, 1985;Toro et al, 1987;Cook et al, 1987;Capua et al, 1998Capua et al, , 1999. Brown & Bracewell (1985) found high cross-reactions between serotypes in the HI test.…”

“…Traditionally, strain classification into serotypes has been by VNTs performed in various systems, including embryonated eggs (Dawson & Gough, 1971;Cunningham, 1973;Cowen & Hitchner, 1975;Lohr, 1976Lohr, , 1977Gelb et al, 1981Gelb et al, , 1989Gelb et al, , 1991Davelaar et al, 1984;Picault et al, 1986;Karaca et al, 1990;Cubillos et al, 1991;Capua et al, 1998), cell culture (Hopkins, 1974;Cowen & Hitchner, 1975;Wadey & Faragher, 1981;Csermelyi et al, 1988), or TOCs (Johnson & Marquardt, 1975;Darbyshire et al, 1979;Cook, 1984;Cook et al, 1987Cook et al, , 1999Hinze et al, 1991;Ignjatovic & McWaters, 1991;Cubillos et al, 1991;Parsons et al, 1992;Dhinakar Raj & Jones, 1996b;Ignjatovic & Ashton, 1996;Wang et al, 1997). There are several reports on serotyping by the HI test (Lashgari & Newman, 1984;Brown & Bracewell, 1985;Toro et al, 1987;Cook et al, 1987;Capua et al, 1998Capua et al, , 1999.…”

Genetic analysis revealed LX4 genotype strains of avian infectious bronchitis virus became predominant in recent years in Sichuan area, China

“…Serotypes and genotypes are usually used to character IBV strains. Traditionally, VN and HI tests were used to differentiate and classify IBV strains [13,14], and monoclonal antibodies have been developed against several serotypes of IBV [15][16][17], although serotype-specific monoclonal antibodies are only available for a small number of serotypes. In recent researches, S1 gene sequencing and subsequent genetic analysis have provided a fast and accurate method for classifying and predicting IBVs [18][19][20][21][22][23].…”