Recovery of Clostridia from Human Feces. Development of a Method

摘要

A method allowing consistent recovery of clostridia from human feces is presented. During development of this procedure, clostridia were isolated in 105 of 161 specimens. Maximal dilution at which isolations were obtained varied from .001 to 10 to the minus 9th power, with a median of .00001. Diet was without effect. The final procedure employed heated dilutions of .01, .001, and .0001 with blood agar and sulfite-polymyxin-sulfadiazine (SPS) agar. Unheated dilutions were .00001, .000001, and 10 to the minus 7th power with blood agar and .0001, .00001, and .000001 with SPS agar. Clostridia were isolated from 20 to 21 samples. On the basis of morphology, 312 clostridial isolates were divided into seven groups. The most frequent type consisted of slender rods with terminal spores. By streaking heated suspensions to blood agar, C. perfringens was recovered from 20 of the 161 samples. Media used by others are discussed, and the usual fecal clostridia are listed. (Author)