Sampling variability in the microbiological evaluation of expectorated sputa and endotracheal aspirates

A five-center study was conducted with the aim of determining how reproduci bly expectorated sputa and tracheal aspirates could be sampled when prepari ng Gram-stained smears and inoculating cultures. With both specimen types, excessive variation was noted among Gram stain results obtained from replic ate smears. Less variation was noted among culture results, especially with tracheal aspirates.