Multiplex real-time PCR and blood culture for identification of bloodstream pathogens in patients with suspected sepsis.

Severe sepsis is increasingly a cause of death. Rapid and correct initial antimicrobial treatment reduces mortality. The aetiological agent(s) cannot always be found in blood cultures (BCs). A novel multiplex PCR test (SeptiFast (alpha version)) that allows identification of 20 bacterial and fungal species directly from blood was used, comparatively with BC, in a multicentre trial of patients with suspected bacterial or fungal sepsis. Five hundred and fifty-eight paired samples from 359 patients were evaluated. The rate of positivity was 17% for BC and 26% for SeptiFast. Ninety-six microorganisms were isolated with BC, and 186 microorganisms were identified with SeptiFast; 231 microorganisms were found by combining the two tests. Of the 96 isolates identified with BC, 22 isolates were considered to be contaminants. Of the remaining 74 non-contaminant BC isolates available for comparison with SeptiFast, 50 were identified as a species identical to the species identified with SeptiFast in the paired sample. Of the remaining 24 BC isolates for which the species, identified in the BC, could not be detected in the paired SeptiFast sample, 18 BC isolates were identified as a species included in the SeptiFast master list, and six BC isolates were identified as a species not included in the SeptiFast master list. With SeptiFast, 186 microorganisms were identified, 12 of which were considered to be contaminants. Of the 174 clinically relevant microorganisms identified with SeptiFast, 50 (29%) were detected by BC. More than half of the remaining microorganisms identified with SeptiFast (but not isolated after BC) were also found in routine cultures of other relevant samples taken from the patients. Future clinical studies should assess whether the use of SeptiFast is of significant advantage in the detection of bloodstream pathogens.

[Antibiotic sensitivity of 32 strains of Stomatococcus mucilaginosus in oral medicine patients in community practice]. / Sensibilité aux antibiotiques de trente-deux souches de Stomatococcus mucilaginosus chez des patients de stomatologie en pratique de ville.

Susceptibility to eleven antibiotics of 32 strains of Stomatococcus mucilaginosus isolated from gingival or dental samples in patients who are nor hospitalized nor receiving antibiotics since six months was tested by diffusion and MIC. 12.5% of strains were resistant to macrolides and lincosamides. This result is significantly different from the result obtained with strains isolated from patients hospitalized for chronic pulmonary problems (36%). This resistance to antibiotics could be due to selection pressure as shown by the high incidence of resistant strains in antibiotic treated patients.