Changing fecal Escherichia coli flora during travel.

The Escherichia coli flora of 23 Peace-Corps volunteers were monitored during the first six weeks of their stay in Morocco. Fifteen (65%) had a total of 21 diarrheal episodes, six of which were associated with enterotoxigenic Escherichia coli. Bioserotypes O25:K7:H42, O128:H-, O169:H- and O20H- were found. These or other characteristically enterotoxigenic Escherichia coli bioserotypes were not found in asymptomatic persons, except in one case. In general, the Escherichia coli flora not only changed after the volunteers arrived in Morocco but continued to change during the six weeks of investigation.