Before the publication of the M40-A standard by the United States National Committee for Clinical Laboratory Standards (NCCLS), no quality control data for swab transport systems (STSs) had been available.Aims:
To compare three commercially available STSs against the published standard to ascertain bacterial survival after a set holding time.Method:
Charcoal and non-charcoal containing swabs were inoculated with standard volumes and numbers of a range of bacteria commonly isolated from clinical material. Bacterial counts were taken at time zero, six, 24, and 48 hours, with the results being compared against the NCCLS standard.Results:
The standard clearly differentiated between the three STSs tested, with one product being superior to the other two products in providing better survival.Conclusion:
The standard now provides manufacturers and users of STSs with meaningful data to provide, purchase, and compare an STS for routine clinical use.