The 5th Pathogenic Neisseriae Conference was held in Noordwijkerhout, The Netherlands, on 15-18 September 1986. It followed San Francisco - USA (1978), Hemavan - Sweden (1980), Montreal - Canada (1982), Asilomar - USA (1984). These conferences will continue to be held in the foreseeing future. The reason for this is because studying pathogenic Neisseriae enables research workers to look at many aspects of bacterial infectious diseases. These aspects include: - Epidemiology and vaccination (section 1) - Genetic aspects of antigenic diversity (section 2) - Outer membrane proteins and IgA-protease (section 3) - Lipopolysaccharides, H8 antigen and peptidoglycan (section ~) - The application of all this knowledge to study pathogenesis (section 5) N. gonorrhoeae has become an important model organism to study mucosal bacterial infectious diseases. Basic knowledge about the bacterial surface, gene- tics and physiology is linked to pathogenic mechanisms such as adhesion to and invasion of epithelial cells, interaction with complement and phagocytic cells and mucosal immune mechanisms. This will continue to be an important research field in the near future. N. meningitidis has become an important model organism to study the epide- miology of potentially epidemic bacterial diseases and against which new type of vaccines are being developed such as outer membrane protein vaccines. The above mentioned topics are covered by papers presented at The 5th Path- ogenic Neisseriae Conference, 1986. I would like to thank Marijke van de Nadort without whom it would have been much harder or even impossible to organize such a meeting.

Table of Contents:
Section 1:Epidemiology and vaccination.- Epidemiology and vaccination.- Class 1 OMP subtyping of meningococci.- The reduction of nitrite by Neisseria meningitidis. Relation to serogroup and serotype.- Monoclonal antibody analysis of meningococcal disease strains isolated in Canada.- Outcome of Neisseria meningitidis serogroup C infection in a small outbreak of disease.- Epidemiology of meningococcal (sub)types in the Netherlands.- Tetravalent meningococcal polysaccharide vaccine. Relationship of dose to immunogenicity and reactogenicity in young adults.- Plasma LPS and clinical pictures in meningococcal disease.- Serological classification of Neisseria gonorrhoeae. Clinical and epidemiological applications.- Epidemiology of meningococcal disease in Switzerland, 1980-1986:Using monoclonal antibodies to classify disease-related isolates.- Intercontinental spread of Neisseria meningitidis clones of the ET-5 complex.- Serological classification of Neisseria gonorrhoeae. Serovars associated with homosexually acquired infection.- A Clonal analysis of Neisseria meningitidis serogroup A.- Epidemiology of infections with pathogenic Neisseriae in Sweden.- Immunoglobulin isotype deficiency and response to meningococcal polysaccharides.- Appearance of new strains associated with group B meningococcal disease and their use for rapid vaccine development.- Monitoring of systemic meningococcal isolates from Norway.- Immune response to meningococcal serogroup B polysaccharide and serotype 2a outer membrane complex vaccines.- DNA hybridisation between the gonococcal cryptic plasmid and plasmids isolated from Neisseria meningitidis and Neisseria lactamica.- Types and subtypes of group B meningococci isolated in Finland from 1976 through April 1986.- Distribution and frequency of strains of Neisseria gonorrhoeae with plasmid-mediated, high- level resistance to tetracycline (TRNG) in the United States.- Distribution and temporal changes in Neisseria gonorrhoeae auxotype/serovar classes in Seattle, Washington.- High-level tetracycline resistance associated with tetM in Neisseria meningitidis and other Neisseriaceae.- Characterization of Neisseria gonorrhoeae isolates from prostitutes with single and multiple infections.- Antigenicity of meningococcal group B oligo- and polysaccharides of defined chain length.- Acquisition of the streptococcal tetM determinant by Neisseria gonorrhoeae.- Comparison of meningococcal outer membrane protein vaccines, solubilized with detergent or C polysaccharide.- Evaluation of sampling methods for surveillance of Neisseria gonorrhoeae strain populations.- Association of meningococcal serogroups and types with the course of disease, the Netherlands 1959-1983 (n = 1221).- Immunogenic activity of gonococcal PI in mice delivered in liposomes, iscoms and detergent complexes.- DNA sandwich - hybridisation assay of the cryptic plasmid from Neisseria gonorrhoeae.- The prevalence and characteristics of arginine, hypoxanthine and uracil requiring strains of Neisseria gonorrhoeae isolated at two London hospitals.- An epidemiological and serological study on duration of protection after meningococcal Group A polysaccharide (APS) vaccination.- Human bactericidal antibody response to meningococcal outer membrane protein vaccines.- Section 2:Genetic aspects of antigenic diversity.- Neisseria genetics.- Linkage of genetic markers in Ahu strains of Neisseria gonorrhoeae.- Specificity in DNA uptake by gonococci.- Genetic and biochemical analyses of protein II.- In vivo loss of gonococcal ?-lactamase plasmid.- Pilin independent binding of Neisseria gonorrhoeae to immobilized glycolipids.- DNA enzymes of Neisseria gonorrhoeae.- Molecular cloning and characterization of a gonococcal surface antigen common to pathogenic Neisseria spp.- The effect of outer membrane proteins and lipopolysaccharide on the ability of Neisseria gonorrhoeae to transfer plasmids by conjugation to Neisseria cinerea.- Molecular principles of pilus antigenic variation in Neisseria gonorrhoeae.- The presence of DNA sequences related to a 4.2Kb cryptic plasmid in the chromosomes of plasmid-free strains of Neisseria gonorrhoeae.- The control mechanism of opacity protein expression in the pathogenic Neisseriae.- Sequence analysis of variant pilin genes from Neisseria gonorrhoeae P9 and immunological properties of pilin polypeptides encoded by cloned genes in Escherichia coli.- Three dimensional structure of bacterial pili.- Interstrain homology of pilin gene sequences in Neisseria meningitidis isolates that express markedly different antigenic pilus types.- Cloning of a gene for methionine biosynthesis from Neisseria gonorrhoeae. Identification by interspecific complementation of Escherichia coli mutants.- Homology between the indigenous plasmids and chromosome of Neisseria gonorrhoeae.- Role of restriction and modification on genetic exchange in Neisseria gonorrhoeae.- Determination of the endonuclease and methylase content of Neisseria gonorrhoeae strain P9 and the cloning therefrom of two functional methylase genes.- Gene conversion accounts for pilin structural changes and for reversible piliation "phase" changes in gonococci.- Section 3:Outer membrane protein and IgA-protease.- Outer membrane proteins and IgA-protease.- Neisseria meningitidis - Outer membrane proteins released into the growth medium.- The isolation and partial characterization of naturally-evolved outer membrane blebs of Neisseria gonorrhoeae.- Monoclonal antibody directed against a surface-exposed protein antigen common in gonococcal strains.- Gonococcal protein III. Purification and chemical characterization of the protein, and the DNA sequence of the structural gene.- Immunobiology of gonococcal outer membrane protein I.- Structural an immunological characterization of cell wall antigens in strains FA638 and CS7 of Neisseria gonorrhoeae.- Characterization of protein I from serum sensitive and serum resistant transformants of Neisseria gonorrhoeae.- High resolution two-dimensional analysis of the proteins of Neisseria gonorrhoeae colony Type 1 and 4, heat shocked and non-heat shocked.- Description of a common, stable, and surface exposed neisserial antigen of 70 kilodaltons.- Characterization of the major iron-regulated protein of Neisseria gonorrhoeae and Neisseria meningitidis.- Purification of native pili and outer membrane vesicles from Neisseria gonorrhoeae.- Restriction site polymorphism in genes encoding type 2 but not type 1 gonococcal IgA1 proteases.- Neisseria gonorrhoeae IgA protease. Secretion and implications for pathogenesis.- Examination of a surface exposed epitope on the protein IA molecule of Neisseria gonorrhoeae.- Development of a tissue culture model for gonococcal invasion.- Antigenic and immunogenic properties of cyanogen bromide peptides from a serotype 5 gonococcal outer membrane protein I.- Characterization of anti-bodies raised to protein I (PI) of Neisseria gonorrhoeae by injection with PI - liposome constructs.- Section 4: Lipopolysaccharides, H8 antigen and peptidoglycan.- Lipopolysaccharide, H8 antigen and peptidoglycan in Neisseriae.- Human immune response to Neisseria gonorrhoeae lipooligosaccharides.- Phenotypic variation of the antigen expression of the lipooligosaccharide of Neisseria gonorrhoeae.- Immunochemical characterization of surface antigen common to the pathogenic Neisseria species.- Serum immune response to common pathogenic Neisseria antigen H8 in patients with uncomplicated gonococcal infection and pelvic inflammatory disease.- Peptidoglycan structure in Neisseria gonorrhoeae grown in continuous culture.- A liposome model of bacteriolysis supports the role of lipooligosaccharide (LOS) and anti-LOS antibody in the complement-dependent killing of N. gonorrhoeae.- Antibodies against Neisseria gonorrhoeae lipooligosaccharide antigens stimulate neutrophil Chemotaxis.- Three distinct gonococcal genes related to H8 antigens.- Antigenic specificity of natural bactericidal activity for serogroup B and C strains of Neisseria meningitidis in human sera.- The immunochemistry of neisserial LOS.- Spontaneous variation of lipooligosaccharide components and epitopes in a strain of Neisseria gonorrhoeae.- Analyses of the immunoaccessibility of H8 antigen and of the functionality of H8 specific monoclonal antibody 10.- Structure and immunochemistry of meningococcal lipopolysaccharides.- Electromorphologic characterization of the lipooligosaccharides of group A Neisseria meningitidis.- Monoclonal antibody identification of shared lipooligosaccharide epitopes of Neisseria meningitidis and Neisseria lactamica.- Human immune response to monoclonal antibody - defined epitopes of Neisseria gonorrhoeae lipooligosaccharides.- Characterization of Neisseria gonorrhoeae lipopolysaccharide biosynthesis genes cloned in Escherichia coli K 12.- Promotion of sleep by gonococcal peptidoglycan fragments. Structural requirements for the somnogenic activity.- The gonococcal C Antigen partitions into phenol and is immunogenic in mice.- Alteration of serum sensitivity in Neisseria gonorrhoeae strain DOV by transformation.- Isolation and characterization of the gonococcal H8 antigen.- The H8 antigen of pathogenic Neisseriae.- Section 5: Application of knowledge to study pathogenesis.- Pathogenesis.- Endotoxin liberation from Neisseria meningitidis isolated from carriers and clinical cases.- Chemical nature of binding properties of an opacity-associated Protein II of the gonococcus.- Non-secretion of blood group antigens. A genetic factor predisposing to infection by Neisseria meningitidis.- Exposure to myeloid and other mammalian cells increases Neisseria gonorrhoeae 02 utilization. Implications for pathogenesis.- Anaerobic growth of Neisseria gonorrhoeae induces and represses synthesis of outer membrane proteins.- Anaerobically expressed outer membrane proteins of Neisseria gonorrhoeae are recognized by antibodies present in the sera of PID patients.- Metabolic responses of Neisseria gonorrhoeae to human serum and myeloid cells. Adaptation to host defenses?.- Use of the quinone antibiotic streptonigrin to explore the iron and oxygen metabolism of Neisseria gonorrhoeae. Mechanisms of antibiotic action and resistance.- Decreased toxicity of paraquat for gonococci due to glucose concentration.- Characterization of cells responsible for ADCC and natural cytotoxicity against gonococci.- Antibodies to outer membrane protein - macromolecular complex (OMP-MC) are bactericidal for serum-resistant gonococci.- The contribution of the alternative and classical complement pathways to gonococcal killing and C3 fixation.- The role of P.II outer membrane proteins in gonococcus - host cell interactions.- Invasion of tissue culture cells by Neisseria gonorrhoeae colony phenotype variants.- Cell surface hydrophobicity of Neisseria gonorrhoeae colony phenotype variants.- Strain-specific direct binding of properdin accounts for variable lysis of Neisseria gonorrhoeae.- The opsonisation and phagocytosis of group B meningococci by polymorphonuclear leucocytes. A comparison of sulphonamide sensitive and resistant strains.- Influence of iron-limited and excess continuous culture on the virulence properties of Neisseria gonorrhoeae.- IgG subclasses reactive with N. gonorrhoeae antigens in the immune response to infection.- Antigenic specificity and biological activity of a monoclonal antibody that is broadly cross reactive with gonococcal protein IIs.- Interaction of Neisseria gonorrhoeae and protein IA with HEp-2 cells.- Enteric immunization reveals a T cell network for IgA responses and suggests that humans possess a common mucosal immune system.- Serum and vaginal fluid antibodies against the major iron-regulated protein in women with gonococcal pelvic inflammatory disease or uncomplicated infection.- The Ability of Neisseriae to use lactoferrin as an iron source depends on the presence of a lactoferrin binding site.- Gonococci in vivo and in vitro - Further studies on the host and bacterial determinants of gonococcal resistance to killing by human serum and by phagocytes.- Differential expression of "Fe-repressible" and "growth-rate-sensitive" proteins in Neisseria meningitidis and Neisseria gonorrhoeae.- Mechanisms of stable serum resistance of Neisseria gonorrhoeae.- Iron and meningococcal disease - S-ferritin, S-iron, and S- total iron binding capacity in meningococcal disease patients and patient controls.- Adherence of Neisseria meningitidis to human buccal and pharyngeal epithelial cells. Relationship to bacteriocin-like substances.- Infant rat model for meningococcal group B infection.- 'Interaction of lysosomal cathepsin G. with N. gonorrhoeae'.- Cytopathic effects of the pathogenic Neisseriae. Studies using human fallopian tube organ cultures and human nasopharyngeal organ cultures.- Polyphosphate-mediated release of iron from transferrin - A possible mechanism for acquisition of iron from transferrin by Neisseria gonorrhoeae.