Rarity of tylosin resistance in human pathogenic bacteria.

Of 3812 human cultures of Staphylococcus aureus, Streptococcus pyogenes and Campylobacter species only 1.0 per cent were resistant to tylosin, an antibiotic used extensively in animals but not in man. There was no evidence for a significant animal source of these resistant cultures, a result which provides further evidence for the rarity of the flow of resistant organisms (or their genes) from animal sources to human beings.