C-169. An Evaluation of an Automated System for Processing Clinical Swabs

G. A. Jones, R. B. Matthews;
Plymouth Hosp. NHS Trust, Plymouth, UNITED KINGDOM.

Background: Since Councilman recommended the use of cotton wool swabs for transporting clinical material in 1893[1] there have been few changes apart from the introduction of gel transport media in the 1940s. Copan Italia recently introduced the eSwab - a flocked swab in 1ml liquid Amies medium designed to significantly improve sample absorption and release. Dynacon Inc. (Ontario, Canada) has now created a robotic system “AccuPAS” for the automatic inoculation and streaking of Copan’s eSwab onto barcode-labelled culture plates. Methods: The automated processing of eSwabs was evaluated against the current manual system using Copan’s regular plain fibre M40 swabs. Triplicate swabs were inoculated with 100ul aliquots of bacterial dilutions ranging from 103-108 CFU per ml. Bacteria tested included S. aureus, S. pneumoniae, S. pyogenes, N. gonorrhoeae and H. influenzae. Swabs were stored at 20-25°C and cultured at 0hrs for S. aureus and 0, 24, 48hrs for the remaining organisms. Culture plates were incubated and the resulting number of colonies counted. Protocol was based on the CLSI procedure M40-A. Results: AccuPAS was shown to be able to recover bacteria from low bioload samples as well as being able to achieve isolated colonies from those with a high bioload. The system was accurate, the cultures produced were very uniform and the streaking quality excellent. AccuPAS was user friendly and reliable. Bacterial recovery at 0hrs was better from the eSwabs processed with AccuPAS for all organisms. Acceptable recovery after storage at 20-25°C for 24/48hrs was achieved for all organisms from the AccuPAS processed eSwabs and, compared to the plain M40 product, showed improved recovery for N. gonorrhoeae. Conclusions: The automated processing of eSwabs has proved to be at least as effective as a manual system in bacterial recovery. It has the added advantage of releasing staff to perform other tasks; the eSwab also provides more sample volume. The use of such automation in clinical microbiology shows potential and in its current format may be best suited to single organism screening such as MRSA.
1. Amer J Med Sci. 1893;106:540-552