Identification of strains of Escherichia coli in stool samples by direct fluorescent antibody tests

Abstract

A study of 121 patients with acute diarrhea was made at the Pediatric Clinic of the Santa Casa de S. Paulo (the S. Paulo Charity Hospital). Etiological diagnosis of 121 cases was carried out through the classical bacteriological method and direct fluorescent antibody tests for the identification of E. coli. The antibiotic sensitivity of these bacteria to different antimicrobials was determined by the Minimum Inhibitory Concentration (MIC) method. Fifty-six positive cases were found; 89.3% of which corresponded to different serotypes of enter o pathogenic E. coli (89.3%), when the direct fluorescent antibody test was used. The classic bacteriological method bared four Salmonella strains and two Shigella. The MIC showed the E. coli to be more sensitive to Gentamicin and Amikacin than to other antibiotics.