Association of infection caused by Pseudomonas aeruginosa serotype O11 with intravenous abuse of pentazocine mixed with tripelennamine.

From July 1979 to June 1983, 25 of 40 intravenous drug addicts with systemic infections had Pseudomonas aeruginosa as the etiological agent; by 1982, P. aeruginosa had replaced Staphylococcus aureus as the most common pathogen. At least 21 of the 25 addicts with P. aeruginosa infection abused pentazocine mixed with tripelennamine (commonly known as T's and blues) compared with 6 of 15 addicts infected with other pathogens (P = 0.006). Of the 25 P. aeruginosa isolates, 23 were of serotype O11. Phenotypic patterns in isolates from addicts and in 22 serotype O11 control isolates from nonaddicts were determined by pyocin and electrophoretic enzyme typing, as well as by susceptibility to heavy metals and antibiotics. Of 25 isolates from addicts, 20 were identical or differed by only one marker, whereas the 22 nonaddict serotype O11 isolates were distributed among 17 distinct phenotypic patterns. We postulate that the emergence of P. aeruginosa as the major cause of deep infection in addicts is a consequence of contamination of their paraphernalia during preparation of pentazocine and tripelennamine for self-injection. The phenotypic similarity among isolates from addicts may reflect acquisition from related environmental sources and an unusual ability of certain serotype O11 strains to survive preparation of the drugs or to be invasive.