Identification of fecal Escherichia coli from humans and animals by ribotyping

Abstract

Fecal pollution of water resources is an environmental problem of increasing importance. Identification of individual host sources of fecal Escherichia coli, such as humans, pets, production animals, and wild animals, is prerequisite to formulation of remediation plans. Ribotyping has been used to distinguish fecal E. coli of human origin from pooled fecal E. coli isolates of nonhuman origin. We have extended application of this technique to distinguishing fecal E. coli ribotype patterns from human and seven individual nonhuman hosts. Classification accuracy was best when the analysis was limited to three host sources. Application of this technique to identification of host sources of fecal coliforms in water could assist in formulation of pollution reduction plans.

FIG. 1

Two-dimensional spatial plot of riboprints of fecal E. coli from all eight host sources studied. Hosts are identified by the following letters: h, human; p, pig; c, cattle; e, horse; d, dog; w, chicken; t, turkey; and g, migratory geese. Can1 is on the x axis, and Can2 is on y axis. There were 84 hidden observation points which were invisible due to overlapping.

FIG. 2

Spatial plot of riboprints of fecal E. coli from cattle, pigs, and humans. Positions of patterns are represented as follows: c, cattle; p, pigs; and h, humans. Can1 is on the x axis, and Can2 is on the y axis. There were 28 hidden observations.

FIG. 3

Spatial plot of riboprints of fecal E. coli from cattle, pigs, and chickens. Positions of patterns are represented as follows: c, cattle; p, pigs; and w, chickens. Can1 is on the x axis, and Can2 is on the y axis. There were 21 hidden observations.

FIG. 4

Spatial plot of riboprints of fecal E. coli from humans, dogs, and geese. Positions of patterns are represented as follows: h, humans; d, dogs; and g, geese. Can1 is on the x axis, and Can2 is on the y axis. There were 24 hidden observations.