Antimicrobial activity of street heroin.

Street heroin and injection paraphernalia have been implicated as sources of bacteria causing infections in drug abusers [1]. Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus are common etiologic agents. In a previous study of the microbiology of street heroin and injection paraphernalia, Bacillus species was the predominant isolate [2]. We did not find S. aureus, but one study reported isolates of identical phage type from heroin powder and from an infected patient [3]. To reconcile the results of our recent investigation among drug abusers with panophthalmitis, we theorized that the drug mixture might have an antibacterial effect. Of the samples of street heroin tested, all except one were bactericidal against S. aureus. The single sample with no heroin content was not bactericidal against one isolate of S. aureus and was the only sample that exhibited some degree of inhibitory and bactericidal activity against P. aeruginosa. All samples were bactericidal against the two isolates of B. cereus tested. Quinine exhibited bactericidal activity against S. aureus and B. cereus but was ineffective against P. aeruginosa. Our findings indicate that most samples of street heroin have antibacterial effects against S. aureus and B. cereus but no activity against P. aeruginosa. Such activity may be due to the quinine content of the mixture. The apparent lack of recovery of S. aureus from street heroin may be partially explained by this phenomenon.