ANTIMICROBIAL RESISTANCE OF SHIGELLA ISOLATES CAUSING TRAVELERS DIARRHEA

Shigella isolates were identified as a cause of traveler's diarrhea in 67 (10%) of 675 patients and were tested for resistance to seven anti microbial agents in a comparative study with those causing nontraveler 's diarrhea in Spain. Ampicillin and chloramphenicol resistance was mo re frequent in Shigella flexneri (60 and 46%, respectively) than in Sh igella sonnei (32 and 18%, respectively) and in travel-related isolate s (P < 0.05 and 0.04, respectively). Of S. sonnei isolates from patien ts with traveler's diarrhea, 73 and 54% showed tetracycline and trimet hoprim-sulfamethoxazole resistance, respectively, compared with only 8 % of isolates from patients without a history of travel to developing countries (P < 0.007 and P < 0.0002). Low-level resistance to cephalos porins was found, whereas quinolone-resistant strains were not detecte d among travel related Shigella isolates. Thus, quinolones may be an e ffective alternative therapy for travel-related shigellosis.