[Coliphages, viral indicators of contamination].

This paper illustrates the importance of coliphages, which are specific bacteriophages for Escherichia coli strains, as viral indicators, and suggests the usefulness of a routine coliphage search in the detection of viral contamination. The samples studied consisted of 57 surface water, (46 of sea water and 11 of river water), 2 of mud taken from biological treatment plants and 3 samples of sludge. The results revealed that coliphages can be considered valid indicators of viral contamination as they show a good response to the general standards established for indicators.

[Methodological possibilities for in vitro evaluation of the antibiotic sensitivity of bacterial plaque from periodontal pockets].

Two different methods for making the subuletic bacterial antibiogram were compared, namely, the inhibition halo technique and that of percentage reduction. The first, of the more classical nature, is based on the introduction of the antibiotic inside a small cavity made in the culture medium, which leads to the formation of circular haloes around the cavity itself. The magnitude of the hales is all the greater, the more effective the antibiotic.