EMERGING IN-VITRO RESISTANCE TO QUINOLONES IN PENICILLINASE-PRODUCINGNEISSERIA-GONORRHOEAE STRAINS IN HAWAII

The susceptibilities of 37 penicillinase-producing strains of Neisseri a gonorrhoeae (PPNG), isolated in Hawaii from December 1991 through Ja nuary 1994, were determined to ciprofloxacin and ofloxacin, fluoroquin olone agents currently recommended by the Centers for Disease Control and Prevention as alternative regimens for the treatment of uncomplica ted gonorrhea. Nine isolates (24.3%) exhibited decreased susceptibilit ies (MICs, greater than or equal to 0.06 mu g/ml) to ciprofloxacin and ofloxacin, Ciprofloxacin MICs for three isolates (8.1%) were 2.0 mu g /ml; these isolates belonged to the auxotype/serovar class Pro/IB-7 an d possessed the 3.2-MDa beta-lactamase and the 24.5-MDa conjugative pl asmids. Six strains for which ciprofloxacin MICs were 0.06 to 0.125 mu g/ml belonged to a variety of gonococcal phenotypes. Strains for whic h ciprofloxacin MICs were 2.0 mu g/ml were isolated from persons who h ad traveled to, or were sexual contacts of persons who had recently tr aveled to, Southeast Asia. Persons infected with these isolates had be en treated with ceftriaxone (250 mg intramuscularly, single dose); the refore, none of these cases were associated with clinical failure foll owing the use of fluoroquinolone therapy. Further studies are needed t o confirm the clinical and public health significance of increased in vitro resistance to ciprofloxacin and ofloxacin in N. gonorrhoeae.