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Biomedical subjects

P M WATERWORTH

Publications and source records attributed to P M WATERWORTH.

At least 19 recordsLinked to original sources
PubMed1965

STUDIES ON THE "CARRY-OVER" OF ANTIBIOTICS USING THE CELLOPHANE TRANSFER TECHNIQUE.

The cellophane transfer technique has been used in the clinical laboratory as a guide to combined treatment and also to study the bactericidal actions of all common antibiotics, but during recent work it became clear that some antibiotics are absorbed on to the cellophane and enough may be carried through on to the fresh medium to inhibit growth of survivors even after transfer. The present investigation has been made to determine the maximum concentrations which can be used without risk of inhibition by carry-over Certain concentrations are recommended and also the depth of agar, and with this there should be no risk of invalidating these bactericidal tests by bacteriostatic inhibition of survivors of carry-over. In clinical studies it is usually only necessary to test one of each group of antibiotics. That showing least carry-over should be used.

Agar↗
PubMed1964

ANTIBIOTIC SENSITIVITY OF PROTEUS SPECIES.

A study has been made of the antibiotic sensitivity pattern of 96 strains of Proteus isolated from clinical material and a further 29 strains kindly supplied by Dr. Patricia Carpenter. The results have been analysed in relation to the different species. The effect of electrolytes on the penicillin sensitivity of Proteus species has also been examined.

Ammonia↗
PubMed1962

Methods of testing combined antibiotic bactericidal action and the significance of the results.

A DESCRIPTION IS GIVEN OF TWO METHODS OF MEASURING COMBINED ANTIBIOTIC BACTERICIDAL ACTION: a test in liquid medium with subculture and the cellophane transfer method. It is emphasized that information so obtained is necessary in order to predict the effect of combined treatment, particularly in bacterial endocarditis due to organisms not fully sensitive to penicillin. Eight case histories are given, in all of which such a prediction was fulfilled, one of failure and seven of success from the use of five different combinations. The cellophane transfer method was applied to the study of the nature of combined antibiotic action on multiple strains of several bacterial species. The results were rarely uniform for any given combination and species: the necessity for individual tests as a guide to treatment is thus confirmed.Modifications of the theory of combined action formulated by Jawetz are proposed.

Anti-Bacterial Agents↗