A total of 3,598 genital specimens from men and women was cultured for Haemophilus spp. using a simple selective culture method. Two hundred and thirty three samples (6.5%) were positive for Haemophilus spp., 216 Haemophilus parainfluenzae and 28 Haemophilus influenzae strains being isolated. Biotyping demonstrated that Haemophilus parainfluenzae biotype II was dominant at all sites, especially the male urethra, comprising 59% of all Haemophilus strains isolated. On the other hand, Haemophilus influenzae biotype IV was isolated from only six patients and thus was not a major genital biotype. The respective proportions of the two Haemophilus spp. recovered from various mucosal sites led to the supposition that the genitourinary colonization originated either from the upper respiratory tract or the gastrointestinal tract.

A monoclonal immunoglobulin M antibody, HP15/36, was produced by a hybridoma cell line prepared by fusion of mouse myeloma cell line Sp2/O with spleen cells of mice immunized with Helicobacter pylori D273 (French strain). Immunoelectron microscopy of whole bacteria and ultrathin sections showed that the determinant was located outside the bacterial cell, possibly in the outermost areas. This external reactivity was observed by immunofluorescence and immunoperoxidase assays and was confirmed by immunogold study at the ultrastructural level. The reactive epitope was formol and picric acid resistant and allowed the detection of the bacterium on fixed tissue biopsy specimens. The reactive component was extracted with phenol-water. Immunoblotting with such an antigen exhibited a clearly positive reactivity at a molecular mass between 50 and 120 kDa. This reactivity was suppressed by periodate oxidation, suggesting a carbohydrate epitope. The diagnostic value and significance of this polysaccharide in microbe-host interactions remain to be determined.

Immunoblotting experiments on hyperimmune rabbit serum and sera from patients with Helicobacter pylori gastritis showed a consistent antibody response to a 19-kDa outer membrane protein antigen. A monoclonal antibody, designated HP 40, which reacted by Western immunoblotting with this protein was produced. It was shared by all H. pylori strains tested (D 273, NCTC 11637, and 24 wild strains) but not by the thermophilic Campylobacter species, Campylobacter fetus, Helicobacter mustellae, or Helicobacter fennelliae. Immunogold staining suggested that the 19-kDa antigen was exposed on the outer surface of the bacteria. Its functional role and effectiveness as a serological diagnostic tool are under study.

Ribotyping was investigated as a means of distinguishing ten different serotyped reference strains and seven epidemiologically unrelated isolates of Mycobacterium avium-Mycobacterium intracellulare using a labelled 16S rDNA probe. Thirteen restriction enzymes were screened towards an accurate discrimination of strains. Two selected restriction enzymes (SacI and ClaI) enabled us to classify the 17 strains into ten ribotypes with an index of discrimination of 0.897. Typeability and reproducibility of the method reached 100%. The patterns obtained exhibited polymorphism of RE fragments within and outside the 16S rRNA gene and may be useful for epidemiological studies.