Serratia marcescens pseudobacteraemia in neonates associated with a contaminated blood glucose/lactate analyzer confirmed by molecular typing.

Three episodes of Serratia marcescens pseudobacteraemia occurred on a neona tal intensive care unit. Following the first two cases, one full term and o ne pre-term infant, the source was identified as a glucose/lactate analyzer . Blood culture and environmental isolates of the organisms involved were i ndistinguishable when subjected to pulsed-field gel electrophoresis of Spe 1 digests and PCR ribotyping. Failure to recognize pseudobacteraemia in neo nates results in inappropriate therapy for the individual and increased ant ibiotic pressures on the unit. Attention to the possibility of cross infect ion when using automated analyzers is required to minimize the risks of tru e or pseudoinfection to patients.