Monitoring of antibiotic resistance in shigellae isolated in The Netherlands 1984-1989

During surveillance of antimicrobial resistance in Shigella strains isolated in the Netherlands from 1984 to 1989 and forwarded to the National Institute of Public Health and Environmental Protection for typing, sensitivity to twelve antimicrobial agents was assessed. High rates of resistance to the older drugs of choice in treating shigellosis were found, i.e. ampicillin and trimethoprim-sulfamethoxazole. Ampicillin resistance varied from 33 to 53% among Shigella flexneri strains and from 10 to 17% among Shigella sonnei strains. Trimethoprim and trimethoprim-sulfamethoxazole resistance increased from 8% to about 25% among Shigella flexneri and from 16 to 46% among Shigella sonnei isolates. All strains were susceptible to the newer quinolones, but five strains resistant to nalidixic acid showed decreased susceptibility to norfloxacin. Approximately 10% of the isolates were resistant to the combination of ampicillin, trimethoprim and sulfamethoxazole.