[Study of in vitro antimicrobial resistance of positive coprocultures to Shigella sp].
BACKGROUND: The gastroenteritis caused by Shigella sp (shigellosis) represents an important cause of morbimortality, especially in children under two years old. It is well known that the proper antimicrobial therapy can improve clinical state and diminish the disease dissemination. Increasing levels of resistance to drugs commonly used in the treatment of shigellosis have been described, and its sensibility has not been recently evaluated in our setting. OBJECTIVE: To evaluate the Shigella antimicrobial resistance in our setting. METHODS: A retrospective study was conducted using 106 coprocultures of patients, hospitalized or not, who have been assisted at HCPA and at HPV, during the period of 1994 to 1996, with the sensibility test done through the Kirby-Bauer technique of diffusion discs. RESULTS: Out of the 106 coprocultures studied, 35 (33%) came from HPV and 71 (67%), from HCPA. Considering the species, 58.8% were S. flexneri, 39.6%, S. sonnei, 0.9%, S. disenteriae and 0.9%, S. boydii. The resistance levels to usually indicated antibiotics were: ampicillin -57.5%, trimethropim-sulfamethoxazol -75.5%, and nalidixic acid -7.5%. CONCLUSIONS: These results show significant (p<0.001) in vitro antimicrobial resistance to ampicillin and trimethoprim-sulfamethoxazol and low resistance to nalidixic acid among Shigella sp. Thus, nalidixic acid may be an option to treat infections caused by resistant organisms.