Controlled Evaluation ofHypertonic Sucrose Mediumata1:5 Ratio ofBloodtoBrothforDetection ofBacteremia and Fungemia inSupplemented Peptone Broth

Thevalue ofhypertonic mediainthedetection ofbacteremia andfungemia is controversial, sinceprior clinical trials haveyielded conflicting results with different media. Earlier, we showedthattheaddition of10%sucrosetosupplemented peptone broth ata1:10ratio ofbloodtobrothyielded better recoveryof Staphylococcus epidermidis, theEnterobacteriaceae, Pseudomonas aeruginosa, andyeasts. Toevaluate theeffect of10%sucroseonbloodcultured ata1:5ratio, we compared theyield andspeed ofdetection ofclinically important microorganismsfromadultpatients in5,839bloodsamples cultured insupplemented peptonebroth with0.03%sodiumpolyanetholesulfonate withandwithout 10% sucrose.Theatmosphere ofincubation (open venting units), 1:5ratio ofbloodto broth, andmethods ofprocessing were thesame forbothbottles. Recovery of facultative gram-positive (P< 0.02) andgram-negative (P< 0.02) bacteria was improved, buttherecoveryofanaerobic gram-negative bacteria was bothreduced (P< 0.01) anddelayed (P< 0.02) bysucrose.Thetotal yield ofmicroorganisms including fungi, however, was increased withsucrose.Theeffect ofsucroseon bloodcultures appearstodepend on theratio ofbloodtobroth aswell ason the mediumusedandstrains ofmicroorganisms encountered. Theaddition of10to30%sucrose orsorbitol tobloodculture mediahasbeenadvocated to