A rapid method for the characterization of enteric pathogen using paper discs.

The changing concept of warfare and civil defense during the last decade has stimulated a re-evaluation of diagnostic methods employed in medical bacteriology. The expeditious laboratory diagnosis of communicable diseases occurring epidemiologically has become a matter of great importance. For example, epidemics of dysentery encountered in the Armed Forces may be unprecedented in size; Hardy et al. (1952) following such an experience have emphasized the pressing need for acceleration in the diagnosis of enteric infections. Investigations of epidemics or sporadic outbreaks of bacillary dysentery, infantile diarrhea, typhoid and paratyphoid fevers are complicated by the slowness of the usual bacteriologic procedures and the complexity of conventional identification systems. Indeed, newer knowledge regarding the biochemical and serologic characteristics of the enteric pathogens has served to lengthen the conventional diagnostic methods used to characterize them. In effect, the old and sometimes superfluous techniques continue to be used plus the newer systems which could have, partially at least, replaced them. This report describes a rapid and economic procedure which combines the desirable features of a boosterscreening system reported by Sanders (1953) with the practical utility of the paper disc techniques described by Soto (1949) and Snyder (1954). The method described will (a) reduce over-all laboratory time required for the definitive identification to less than 24 hr; (b) enhance the probability of detecting multiple bacterial serotypes; (c) provide a simple and economic procedure easily adapted to the working structure of all laboratories.