Comparison of Easy-Flow Copan Liquid Stuart's and Starplex Swab Transport Systems for Recovery of Fastidious Aerobic Bacteria

Abstract

Because samples are frequently submitted on swabs from distant sites, viability of the organism must be maintained. We compared two transport systems, a new Copan Liquid Stuart's swab with an Easy-Flow swab applicator and the Starplex Liquid Stuart's swab. The purpose of the study was to assess the release and/or recovery of organisms from the Copan system compared to that from Starplex. Triplicate swabs were seeded with 3 dilutions of Neisseria gonorrhoeae, Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae. Although the amount of the initial inoculum was the same for both transport systems, recovery by the roll-plate method at time zero was consistently increased with the Copan system (31 to 87% higher). This is the most important finding in this study. With N. gonorrhoeae, subsequent recoveries were similar for Copan and Starplex but poor for both systems. With N. meningitidis and Haemophilus, higher levels of recovery were clearly obtained with Copan (P < 0.05 to P < 0.001). With Streptococcus, subsequent recoveries for Copan and Starplex were mixed. In conclusion, Copan generally demonstrated better recovery of organisms compared to Starplex even (and especially) at time zero.Proper transport of clinical specimens for culturing infectious agents may be the most important factor affecting the successful evaluation of these specimens. Because many samples on swabs are submitted from sites distant from clinical microbiology laboratories, it is essential that viability of the organism be maintained. While tissues and aspirates remain the specimens of choice, swabs are still commonly submitted to clinical microbiology laboratories for culture. A transport system that will maintain viability of the organism for 24 to 48 h becomes a necessity, as the need to transport these specimens a greater distance becomes a reality. Release of the bacteria from the swab also becomes an important factor. In this study, we compared two transport systems (the Copan Liquid Stuart's swab with an Easy-Flow swab applicator and the Starplex Liquid Stuart's swab) for recovery of fastidious aerobic bacteria. Although both swabs tested use liquid Stuart's as the transport medium, the Copan swab system incorporates a newly designed swab applicator that is said to improve the release of bacteria onto culture plates (5).(This work was presented in part at the 103rd General Meeting of the American Society for Microbiology, Washington, D.C. [C. Drake, J. Barenfanger and G. Lawhorn, Abstr. 103rd Gen. Meet. Am. Soc. Microbiol., abstr. C-045, p. 125, 2003].) MATERIALS AND METHODSThe survival of the following four fastidious aerobic bacteria in the two transport systems at two temperatures was evaluated: Neisseria gonorrhoeae ATCC 43069, Neisseria meningitidis ATCC 13090, Haemophilus influenzae ATCC 10211, and Streptococcus pneumoniae ATCC 6305.The bacterial strains were reconstituted and grown on chocolate agar for 18 h at 37 C°to prepare them for testing. Inocula of the isolates were prepared in 0.85% physiological sa...

Comparison of 3 swab transport systems for direct release and recovery of aerobic and anaerobic bacteria

“…In a previous study, a Copan swab with liquid Stuart's was reported to release more organisms than a Starplex liquid Stuart's swab, based on consistently higher time zero CFU recovered (Drake et al, 2005). However, there was no indication as to how this correlated with the actual number of organisms released.…”

“…Swab transport devices should be able to maintain the viability of microorganisms present, and the swab should allow for release of a sufficient representative portion of the specimen material and preserve the integrity of nucleic acids for amplification testing. Limited studies describe organism or specimen release from swabs in transport systems (Drake et al, 2005;Österblad et al, 2003;Roelofsen et al, 1999).Most swab collection devices currently on the market are prepared with rayon or Dacron fibers wound onto the tip of the swab shaft. The new ESwab (Copan Diagnostics, Murrieta, CA) is a nylon-tipped swab prepared by spray-on flocked fiber technology that potentially results in better specimen collection and a more efficient release of specimen material with less specimen entrapment than woven fibertipped swabs.…”

“…Swab transport devices should be able to maintain the viability of microorganisms present, and the swab should allow for release of a sufficient representative portion of the specimen material and preserve the integrity of nucleic acids for amplification testing. Limited studies describe organism or specimen release from swabs in transport systems (Drake et al, 2005;Österblad et al, 2003;Roelofsen et al, 1999).…”

Comparison of the Copan ESwab System with Two Amies Agar Swab Transport Systems for Maintenance of Microorganism Viability

“…Given the increasing frequency of transport delays due to cost containment measures, consolidations, and services being shifted to centralized or reference laboratories, robust transport systems are becoming increasingly relevant. The CLSI M40-A method (2) was used recently to evaluate several swab collection and transport devices for maintenance of bacteria viability (3,4,6,7,8,9).Swab tips, which are typically rayon or Dacron, should be prepared with material that collects sufficient specimen material, is nontoxic to microorganisms, maintains viability in conjunction with the transport medium, and releases specimen material efficiently onto agar media. A new nylon-tipped swab (ESwab; Copan Diagnostics, Inc., Corona, CA) prepared by spray-on flocked fiber technology has been developed for transport of bacteria and viruses.…”

Efficacy of an Anaerobic Swab Transport System to Maintain Aerobic and Anaerobic Microorganism Viability after Storage at −80°C

“…In: Proceedings of the 99th general meeting of the American Society for Microbiology, Chicago, IL). 4,5,9,[11][12][13][14][16][17][18][19][20][21] Frozen semisolid or liquid transport media can maintain bacterial viability for days. 2,6,7,15 The viability of Bacteroides sp.…”