[Coagulase-negative Staphylococcus sp. in blood cultures from infants less than 60 days old: infection versus contamination]. / Staphylococcus sp. coagulase-negativa em hemoculturas de pacientes com menos de sessenta dias de idade: infecção versus contaminação.

OBJECTIVE: The aim of this study was to determine the prevalence of infection versus the prevalence of contamination in infants less than 60 days old who had blood cultures positive for CoNS. MATERIAL AND METHODS: Between February and June - 1993, a number of 45 blood cultures positive for CoNS from 41 patients were studied. Patients were classified in three groups according to their clinical and laboratorial data: I- infected patients, II- non-infected patients and III- dubious. RESULTS: The results showed that 11 patients (26.8%) were included in group I, 25 (61%) in group II (contaminated blood cultures), and 5 (12.2%) in group III. CONCLUSION: It is suggested that more than one blood culture should be requested before treatment with antimicrobials, avoiding unnecessary administration of antibiotics.

[Study of in vitro antimicrobial resistance of positive coprocultures to Shigella sp]. / Estudo da resistência antimicrobiana in vitro das coproculturas positivas para 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.