PubMed Health⌕ Search

Biomedical subjects

P W McWalter

Publications and source records attributed to P W McWalter.

5 recordsLinked to original sources
PubMed1984

Determination of susceptibility of Staphylococcus aureus to methicillin by luciferin-luciferase assay of bacterial adenosine triphosphate.

Susceptibility of 50 strains of Staphylococcus aureus to methicillin was determined by disc diffusion, minimum inhibitory concentration (MIC) test and luciferin-luciferase assay of bacterial adenosine triphosphate (ATP). ATP concentration time curves calculated on eight strains (four sensitive, four resistant) incubated at 30 degrees C indicated 2.5 h as the optimum time for determination of methicillin susceptibility. The ATP concentration and relative light unit (RLU) value of each test broth (antibiotic-containing), expressed as a percentage of its own control broth (antibiotic-free) indicated values of less than 30% for ATP and less than 40% for RLU to be indicative of methicillin sensitivity. Single time point ATP assays carried out on the 50 strains after 2.5 h at 30 degrees C correlated exactly with disc diffusion and MIC. Luciferin-luciferase assay of bacterial ATP appeared to be a reliable, rapid technique for determining the susceptibility of Staph. aureus to methicillin.

Adenosine Triphosphate↗
PubMed1982

Evaluation of a commercially available semi-automated bioluminescence system for bacteriuria screening.

A commercially available semi-automated bioluminescence adenosine triphosphate assay system for rapid detection of significant bacteriuria was evaluated. Excellent reproducibility of results using the bioluminescence apparatus was noted, and there was no bacterial carry-over using a pre-diluter. The results obtained with 2,000 urine specimens tested by bioluminescence and a routine cultural technique were compared. The bioluminescence system gave no false negative results and a bioluminescence positive/culture negative finding of 13.6% in general specimens and 45.0% in ante-natal and maternity specimens. In the latter group, the majority of urines yielded growth of lactobacilli and/or diphtheroids (less than 10(4) organisms/ml) when subcultured on enriched media. Results indicated that bioluminescence may identify urinary tract infections in patients receiving antimicrobial therapy. The advantages of this 45 minute technique for bacteriuria screening are presented.

Adenosine Triphosphate↗