Decrease in the incidence of tetracycline resistance in strains of Neisseria gonorrhoeae in the nineties

Antibiotic resistance determined by standard disc-diffusion method on GC agar with supplement B in 583 strains of Neisseria gonorrhoeae encountered between 1991 and 1996 at the University Hospital of the West Indies, Kingston, Jamaica, were analyzed. The level of penicillin resistance varied between 40% and 28% over the years. Tetracycline resistance fell from 44.2% in 1991 to 23.9% in 1996. Twenty-one per cent of the isolates were resistant simultaneously to both penicillin and tetracycline in 1991. The percentage of such strains decreased to 6.5% in 1996. Ceftriaxone was introduced as a first line drug in treatment of gonococcal infections in the late 1980s. The declining trend of tetracycline resistance may be due to a decrease in the usage of tetracycline in recent years.