Antimicrobial susceptibility of Haemophilus influenzae isolates collected from 4 centers in Brazil (1990-2003).

Antimicrobial susceptibility was determined for 174 Haemophilus influenzae strains collected from patients with infection before and after vaccination against Hib (1990-1999 and 2000-2003, respectively) from 4 public health -laboratories in 3 Brazilian states. All strains were characterized for serotype and beta-lactamase production and in vitro activity of the following antimicrobial agents: -ampicillin, amoxicillin/clavulanate, ceftriaxone, rifampin, chloramphenicol, and trimethoprim/sulfamethoxazole (TMP-SMX). Minimum inhibitory concentrations were determined according to the guidelines of the National Committee for Clinical Laboratory Standards.