Rapid presumptive identification of enteropathogenic Escherichia coli in faecal smears by means of fluorescent antibody. 2. Use of various types of swabs for collection and preservation of faecal specimens.

Faecal specimens that cannot be cultured immediately for enteric pathogens are usually collected in buffered glycerol-saline solution for preservation and transport to the laboratory. Specimens collected in this way are not suitable for fluorescent antibody studies since the glycerol prevents fixation of faecal smears. Transport of specimens frozen with solid carbon dioxide is a satisfactory but expensive method of preservation. The purpose of the study reported in this paper was to explore the possibility of using various types of swabs for preserving and transporting faecal specimens to be examined for enteropathogenic Escherichia coli. Both cotton and Dacron fibres were used and freezing and desiccation were investigated as methods of preservation. The results showed that freezing of faecal swabs was contra-indicated, whereas drying at room temperature enhanced the recovery of enteropathogenic E. coli. Cotton and Dacron swabs gave equivalent results regardless of whether the organisms were detected by culture or by immunofluorescence.