Characterization of enterocoliticin, a phage tail-like bacteriocin, and its effect on pathogenic Yersinia enterocolitica strains.

Yersinia enterocolitica 29930 (biogroup 1A; serogroup O:7,8) produces a bacteriocin, designated enterocoliticin, that shows inhibitory activity against enteropathogenic strains of Y. enterocolitica belonging to serogroups O:3, O:5,27 and O:9. Enterocoliticin was purified, and electron micrographs of enterocoliticin preparations revealed the presence of phage tail-like particles. The particles did not contain nucleic acids and showed contraction upon contact with susceptible bacteria. Enterocoliticin addition to logarithmic-phase cultures of susceptible bacterial strains led to a rapid dose-dependent reduction in CFU. Calorimetric measurements of the heat output of cultures of sensitive bacteria showed a complete loss of cellular metabolic activity immediately upon addition of enterocoliticin. Furthermore, a dose-dependent efflux of K(+) ions into the medium was determined, indicating that enterocoliticin has channel-forming activity.

A novel technique for monitoring the development of bacterial biofilms in human periodontal pockets.

A new technique is presented for analyzing subgingival bacterial plaque. Different materials (polytetrafluoroethylene, gold, dentin) kept for several days in periodontal pockets of patients suffering from periodontitis were analyzed by electron microscopy and fluorescence in situ hybridization (FISH). Those parts of the carriers extending into the deepest zone of the pockets were predominantly colonized by spirochetes and Gram-negative bacteria whereas those segments in contact with a shallower region were colonized by streptococci. Independent of the material used, the bacterial colonization of the carriers appears to be similar. FISH using eubacteria- and species-specific oligonucleotides on semi-thin cross-sections of the carriers in combination with confocal laser scanning microscopy allowed detailed analysis of the architecture of biofilms and identification of putative periodontal pathogens with single cell resolution.

[Use of phototherapy for in newborns with pathologic jaundice]. / Zastosowanie fototerapii u noworodków z zóltaczka patologiczna.

An analysis was done of 596 newborns with intermediate hyperbilirubinaemia treated with phototherapy. The causes of hyperbilirubinaemia were determined. The effectiveness of phototherapy was compared in three groups of newborns: in 300 newborns irradiated by continuous method, in 178 newborns irradiated by intermittent method, and in 118 newborns treated with exchange transfusion and phototherapy. It was found that the effectiveness of phototherapy depended on the initial bilirubinaemia and was similar both after continuous irradiation and intermittent phototherapy. In one-third of the newborns subjected to phototherapy side effects were observed mainly in the form of loose stools.