Factors affecting detection of Brucella melitensis by BACTEC NR730, a nonradiometric system for hemocultures.

摘要: The detection of Brucella bacteremia by subculture does not always correlate with a positive signal in the BACTEC NR730 nonradiometric system (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.). effect inoculum size, pH, sodium polyanetholesulfonate, carbon sources (i-erythritol, pyruvate, monosodium glutamate, D-glucose, and L-alanine), urea release CO2 was evaluated using reference strain melitensis 16M. In standard NR6 vials or without blood, inocula 5 to 10 times larger (at least 265 CFU per vial) than those usually found blood patients brucellosis were necessary produce growth value (GV) 4 days less, similar results obtained supplemented substrates listed above. GVs consistently lower polyanetholesulfonate this agent. Vials no inoculated vial showed turbidity 1 day before became positive, proving that major limiting factor low level an inadequate medium. buffered pH 6.2, faster higher vials. at 6.2 0.3% pyruvate yielded GV first bacterial turbidity.