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

Abstract

Swab transport systems are used for a variety of specimen types and must maintain organism viability throughout the transport process. The Copan ESwab is a new nylon-flocked swab designed to optimize specimen collection and to minimize entrapment of the specimen. We used the quantitative elution method with recommended strains, as described in CLSI document M40-A, to evaluate the ESwab for maintenance of viability of aerobic and anaerobic microorganisms for 0, 6, 24, and 48 h during room temperature and refrigerated temperature storage. The Becton Dickinson CultureSwab MaxV swab and the Remel BactiSwab were used as comparators. The ESwab met CLSI acceptance criteria for all aerobic isolates stored at both temperatures and for all anaerobic isolates stored at refrigerated temperature. The ESwab also met CLSI criteria for four of five anaerobic strains at room temperature. Prevotella melaninogenica was not recovered after 24 or 48 h of room temperature storage with any of the three swab transport systems tested. Overall, the ESwab was equivalent to the Becton Dickinson CultureSwab MaxV swab in organism recovery but recovered more isolates than Remel BactiSwab.Appropriate specimen collection and transport are essential for accurate laboratory diagnosis of bacterial infections. Because of their convenience, swab systems with transport media are often used to collect and transport specimens of various types. These systems must maintain organism viability during transit to a laboratory. 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. This technology provides stronger capillary action and strong hydraulic uptake of liquids, which should result in better specimen collection. This design should also provide more efficient release of specimen material and, therefore, less entrapment of specimen than occurs with typical rayon or Dacron fiber-tipped swabs. The ESwab shaft is scored for ease and consistency of tip breakage into the modified liquid Amies transport medium. A swab capture mechanism in the cap locks the broken swab shaft into the cap when it is fully closed.In MATERIALS AND METHODSOrganisms. The 10 strains tested were those recommended by CLSI document M40-A (2), as follows: Haemophilus influenzae ATCC 10211, Neisseria gonorrhoeae ATCC 43...

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

“…That report did not indicate the number of organisms released and recovered compared with the original inoculum; therefore, organisms might still have been entrapped in the swab material. This study did not assess the ability of any swab system to maintain organism viability over time; however, the ESwab has been shown to be an acceptable swab transport system for maintenance of viability of aerobic and anaerobic organisms (Van Horn et al, 2008). Because molecular detection of microorganisms has increased in recent years, a study defining the acceptability of the ESwab and flocked swab technology to preserve the nucleic acid of organisms might also be warranted.…”

Comparison between Nugent's and Hay/Ison scoring criteria for the diagnosis of Bacterial Vaginosis in WASP prepared vaginal samples

“…Every specimen was collected by using ESwab ® liquid Amies system (Copan Italia, Brescia, Italy,), which represents an optimal liquid medium to conserve and transport the typical bacterial populations present in BV and normal vaginal flora [12,13].…”

Clinical Evaluation of the Walk-Away Specimen Processor and ESwab for Recovery of Streptococcus agalactiae Isolates in Prenatal Screening Specimens

“…In contrast, flocked swabs are constructed with a solid bulbous head that is covered in fibers protruding perpendicularly to the swab shaft. The combination of a liquid-based transport medium along with a flocked swab, such as the ESwab collection device, may more evenly distribute and release microorganisms and has been demonstrated to increase the recovery of bacteria from wound and other sources compared to use with standard fiber wrapped swabs (14)(15)(16)(17)(18). This in turn increases the number of microorganisms inoculated to culture plates and/or other media in a more standardized and reproducible manner, particularly when used with an automated specimen processor, such as the WASP.…”

“…Advancements in technology and automation in the clinical microbiology lab have made available more efficient methods for specimen collection and processing, which have the potential to improve the sensitivity of screening and recovery of GBS and other pathogens (14)(15)(16)(17)(18). The introduction of ESwab (Copan Diagnostics, Murrieta, CA), when used in combination with the Walk-Away specimen processor (WASP) (Copan Diagnostics), has the potential to improve the efficiency and reproducibility of specimen collection, processing, and pathogen recovery through increased sensitivity, specificity, and reduced turnaround time (14)(15)(16)(17)(18)(19). Traditional fiber wrapped swabs coupled with nonnutritive transport medium, such as Liquid Stuart or Amies Gel, aid in the preservation of microorganisms during transit to the clinical laboratory; however, the inefficient transfer or release of microorganisms from a traditional fiber swab may reduce the overall sensitivity of the diagnostic procedure.…”