J.N. Robertson

A European multicenter study of immunoblotting for the serodiagnosis of Lyme borreliosis showed considerable variation in results obtained from tests with a panel of 227 serum samples. Six laboratories used different immunoblot methods, and a wide range of bands was detected in all the assays. Multivariable logistic regression analysis of data from individual laboratories was used to determine the most discriminatory bands for reliable detection of antibodies to Borrelia burgdorferi sensu lato. These bands were used to construct individual interpretation rules for the immunoblots used in the six laboratories. Further analysis identified a subset of eight bands, which were important in all the laboratories, although with variations in significance. Possible European rules, all closely related, were formulated from these bands, although there was no single rule that gave high levels of sensitivity and specificity for all the laboratories. This is a reflection of the wide range of methodologies used, especially the use of different species and strains of B. burgdorferi sensu lato. The panel of European rules provides a framework for immunoblot interpretation which may be adapted in relation to the characteristics of Lyme borreliosis in local areas.

The ability of gonococci to infect the human fallopian tube in both perfusion and organ-culture systems was investigated. Scanning and transmission electron micrographs of the mucosal surface taken 3 hr after perfusion with gonococci showed microvilli adherent to the bacteria, with pili running over the membrane of the host cell. Shortly after challenge gonococci penetrated the mucosal lining to establish expanding foci of infection in the submucosal tissue. Epithelial cells were able to take up massive numbers of gonococci, and lysis of these damaged cells released numerous bacteria into the subepithelial connective tissue. Gonococci also invaded along intercellular junctions. The fact that ciliated cells, which were not invaded by gonococci, were also damaged and exfoliated raises the possibility of a diffusible cytotoxin. These ultrastructural findings are comparable to the known histopathology of acute gonorrhea.

Isogenic variants from a single strain of Neisseria gonorrhoeae were shown to produce two distinct types of pili. These pili, designated alpha and beta, differed in both subunit molecular weight and in ability to attach to buccal epithelial cells.