HUMAN STUDIES TO MEASURE THE EFFECT OF ANTIBIOTIC RESIDUES

This epidemiological study compares the frequency of resistant bacteri a in stool microflora among vegetarians and nonvegetarians over a 12 m onth period. Two well characterized vegetarian populations (one in Bos ton, MA and the other in Loma Linda, CA) as well as appropriate contro ls were studied. No apparent differences in the prevalence of antibiot ic resistance in the microflora were noted; however, vegetarians had a significantly greater incidence of multiantibiotic resistance. E.coli of the same API biotype had the same frequency of antibiotic resistan ce in both vegetarians and nonvegetarians. Quantitative studies showed similar percents of tetracycline resistant facultative isolates and o f ''bacteroides.'' Klebsiella were more common in the stool of the non vegetarians. As shown in previous studies, exposure to animal products either as meat eaters or production workers in a poultry abattoir was not associated with an increased incidence of resistant bacterial flo ra or infections caused by resistant strains.