Modification of Swab Applicators Providing Full Compliance with NCCLS Standard M40-A
Background: Most swab/transport device manufacturers purchase swabs from subcontractors, thus have little control over the process or batch-to-batch variation. Vast improvements have been made in transport device media, packaging, and swab shelf life yet most commercial products do not fulfill all aspects of the NCCLS Performance Standard M40-A.
Methods: Copan, Brescia, Italy, has been focused on NCCLS compliance establishing control of applicator production by bringing all aspects of swab manufacturing in-house. A comprehensive review of swab literature consistently revealed hard data that the use of serum or albumin to coat swabs resulted in prolonged organism survival. This study compares a new Copan product, M40 Transystem Swab containing Amies medium (RED) with their standard Venturi Transystem Amies (BLU) and Starswab II with Amies (STR) Starplex Scientific Inc., Ontario, Can. M40-A procedures for swab vortexing of room temperature-stored swabs was employed using ATCC strains of Neisseria gonorrhoeae, Haemophilus influenzae, Streptococcus pyogenes, Fusobacterium nucleatum, and Peptostreptococcus anaerobius.
Results: The RED swab provided organism survival of all strains after 48h incubation at room temperature, thus, was in full compliance with NCCLS M40-A. The BLU device provided 48 h survival of all organisms except N. gonorrhoeae. STR produced < 1% recovery of N. gonorrhoeae @ 24h and failed to maintain viability of F. nucleatum, H. influenzae, or P. anaerobius @ 48h.
Conclusions: Pioneers of clinical microbiology proved that organism survival on swab applicators could be enhanced by coating them with bovine serum albumin. This is a poorly defined material with lot to lot variation but Copan has refined the protective material by using a simple vegetable protein admixed with specific amino acids as an additive to the glue used to wind swabs onto applicator sticks. Microbiology has simply been a boutique application for Q-tips, and these data suggest that controlled manufacturing incorporating historical performance enhancers has elevated the swab applicator to a medical device with defined performance characteristics.