Direct transmission of Escherichia coli from poultry to humans.
Eight hundred and sixty-four Escherichia coli isolates from workers at the University of Ibadan Teaching and Research Poultry Farm, and 216 isolates from poultry attendants at a commercial poultry farm in the city were found to be resistant to streptomycin, sulphafurazole and tetracycline. In contrast, all 576 and 288 E. coli isolates from village fowls and from villagers respectively were sensitive to these drugs. Isolates from birds in a modern university poultry unit (3744) exhibited the same resistance patterns as those isolated from workers who were in direct contact with the birds. No nalidixic acid-resistant E. coli was isolated from farm workers prior to their assignment to the experimental pen. Following experimental oral infection of birds with E. coli K12 J5 NA+ Lac-, the organism was recovered from the workers who manned the experimental pen. Neither before nor after the experimental infection was any nalidixic acid-resistant E. coli isolated from workers who manned the pen from which birds used in the experiment were selected. Similarly, no drug resistant organisms were isolated from workers outside the poultry unit of the university or commercial farm. The MIC of the drugs against the avian and human E. coli isolates at the university and commercial poultry farms were similar.