Detection of Bacteroides fragilis, Bacteroides thetaiotaomicron, and Bacteroides ovatus in clinical specimens by immunofluorescence with a monoclonal antibody to B. fragilis lipopolysaccharide.

AUTOR(ES)
RESUMO

A total of 1,897 clinical specimens (1,019 aspirates and 876 swabs) were studied by indirect immunofluorescence (IF) with a mouse monoclonal antibody (MAb) against a D-galactose oligomer of Bacteroides fragilis lipopolysaccharide. The MAb has been shown to react with 96% of clinical B. fragilis isolates and with about 50% of Bacteroides ovatus and Bacteroides thetaiotaomicron isolates but not with other aerobic or anaerobic organisms tested. The sensitivity of IF in comparison with culturing was 78.9% for all three species. Of the 32 strains originating from culture-positive, IF-negative specimens, 13 lacked the target determinant for the MAb. Sensitivity was highest with specimens taken from the perineal area (87.1%) and lowest with those taken from undefined sites (56.6%). Sensitivity was better with aspirates (86.8%) than with swabs (72.6%). The specificity of IF was 95.6% for all of the material. Positive and negative predictive values were 51.1 and 98.0%, respectively. Neither long transportation times of specimens nor antimicrobial therapy seemed to correlate with the occurrence of IF-positive, culture-negative specimens. This study shows that a single MAb can be used to establish an IF assay that can complement isolation in the detection of these three members of the B. fragilis group.

ACESSO AO ARTIGO

Documentos Relacionados