RESEARCH PROGRAMS FOR ALERTING, DETECTION AND IDENTIFICATION OF PATHOGENS

摘要

Excretory metabolites from growing cultures of bacteria that have been analyzed by gas chromatographic methods, gave chromatograms that enable not only a distinction among genera and opecies but also among strains of a species.nSince it appears unlikely that the same growth medium would be equally satisfactory for all bacteria, an investigation of the metabolic products ex¬tracted from resting cell suspensions was undertaken. Using a simple sub¬strate, such as glucose in a phosphate buffer, differences in the metabolites were observed when compared to the products resulting from growing cultures. Data indicate that bacteria may be distinguished by this technique as readily as by extracting from a growth medium with the cells in the stationary phase. Incorporating this technique has enabled a considerable increase in the flexi¬bility of the experimental approach to a solution of the detection and identi¬fication problem.nLittle attention has been given to chromatography pretreatment to dif¬ferentiate metabolic products into chemical groups. Further effort is planned in order to facilitate the interpretation of data, give some insight as to frag¬ment identification, and improve the response of the various detectors.nInitial investigations to determine the sensitivity of chromatographic techniques to major products indicate that approximately a thousand cells may be readily detected when the detection system is based on the argon ionization detector response to a major bacterial product. The response of the electron capture detector, however, shows that it may be necessary to monitor the excretory products of only 1.5 cells for the purpose of detection. Inasmuch as detector sensitivities have not been extended, only partial extraction of products employed, and product conversion has not been attempted, it is be¬lieved that even further improvement in sensitivity will result with further study.