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12th International Symposium on Bioluminescence & Chemiluminescence |
Symposium abstracts:
Jackson, Ryan S., Johnson, Sharon M., Jones, Karen, Murphy, Melenie J., Price, Rachel L., Squirrell, David J.
Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK
Patients with suspected bacteremia are tested in hospital laboratories by analysing blood samples for the presence of bacteria. The samples are incubated in culture bottles with an indication system so that the evolution of a marker such as carbon dioxide can be used to signal bacterial growth. The assays are carried out automatically with alarm levels typically triggered when the concentration of bacterial cells reaches a level of 105 ml-1. Conventionally, a positive result is followed up with selective plating and standard antibiotic susceptibility testing which takes 24-48 hours. In this paper we present results showing rapid detection of Staphylococcus aureus in blood samples and the determination of the organism’s responses to a panel of antibiotics. The identification step, using a magnetic bead immunoassay with an adenylate kinase bioluminescence endpoint, could be completed in 15 minutes. The antibiotic susceptibility testing, which was based on comparative growth measurements in the presence and absence of antibiotics, took from 20 minutes to nearly two hours depending upon the type and concentration of the antibiotic. Timely information on the causative agent of the bacteremia and its antibiotic sensitivities could be used to direct the optimum medication for the patient.
This
is a preprint of an article accepted for publication in Luminescence: Copyright
2001 John
Wiley & Sons, Ltd (Wiley website)