Swab Transport Systems Research Articles

Pre-analytical sample stabilization by different sampling devices for PCR-based COVID-19 diagnostics

The outbreak of the SARS-CoV-2 pandemic created an unprecedented requirement for diagnostic testing, challenging not only healthcare workers and laboratories, but also providers. Quantitative RT-PCR of various specimen types is considered the diagnostic gold standard for the detection of SARS-CoV-2, both in terms of sensitivity and specificity. The pre-analytical handling of patient specimens is a critical factor to ensure reliable and valid test results. Therefore, the effect of storage duration and temperature on SARS-CoV-2 RNA copy number stability was examined in various commercially available specimen collection, transport and storage devices for naso/oropharyngeal swabs and saliva. The swab specimen transport and storage devices tested showed no significant alteration of viral RNA copy numbers when stored at room temperature, except for one system when stored for up to 96 h. However, at 37 °C a significant reduction of detectable RNA was found in 3 out of 4 of the swab solutions tested. It was also found that detectability of viral RNA remained unchanged in all 7 saliva devices as well as in unstabilized saliva when stored for 96 h at room temperature, but one device showed marked RNA copy number loss at 37 °C. All tested saliva collection devices inhibited SARS-CoV-2 infectivity immediately, whereas SARS-CoV-2 remained infectious in the swab transport systems examined, which are designed to be used for viral or bacterial growth in cell culture systems.

72-Hour transport recovery of antimicrobial resistant Neisseria gonorrhoeae isolates using the InTray® GC method.

Recovery of Neisseria gonorrhoeae isolates exposed to a range of transport times and temperatures was quantitatively assessed for two transport devices, BioMed Diagnostics' InTray GC® and Copan Diagnostics' Liquid Amies Elution Swab (ESwab®) Collection and Transport System. Respective devices were inoculated with N. gonorrhoeae, exposed to simulated transport conditions and spread-plated from serial dilutions in duplicates onto chocolate agar in order to count CFU (colony-forming units) in the range of 25-250. Baseline CFU/mL averages of time-zero transport for each device was compared to either 24 hour (Eswab) or 72 hour (InTray GC) CFU/mL average to assess recovery of six clinical isolates of N. gonorrhoeae, and differences showing no greater than a 3 log10 (± 10%) decline between comparative time points qualified as acceptable. Our findings suggest that the InTray GC system has the potential to transport clinical isolates for ≤72 hours with acceptable N. gonorrhoeae recovery.

Preservation of viable Taylorella equigenitalis in different commercially available transport systems

The cultural diagnosis of the causal agent of contagious equine metritis (Taylorella equigenitalis) using transport swabs is challenging. Swabs must be placed in Amies charcoal medium, refrigerated during transport, and plated out at the laboratory no later than 48 h after sampling. In this study, the viability of T. equigenitalis strain CIP 79.7T in 11 commercial swab transport systems was initially compared at 1 day and 2 days of storage at ambient (20 ± 3 °C) or refrigerated (5 ± 3 °C) temperature. The four best swab transport systems, systems B, E, F (used as the reference) and K, were then compared at 0, 2, 3, 4, 7 and 10 days at refrigerated temperatures. Statistically significant differences were observed after 10 days only for system K compared to the reference, with approximately 95% viable T. equigenitalis recovered in system K compared to approximately 77% in system F. System K is thus promising for preservation and transport of viable T. equigenitalis for culture.

Laboratory evaluation of the Sigma Transwab\xae transport system for the recovery of Candida species using the Clinical and Laboratory Standards Institute (CLSI) document M40-A2

Rising healthcare complications due to fungal infections increase the importance of efficient specimen collection and maintenance systems for correct identification and diagnosis. The CLSI M40-A2 protocol provides guidelines for laboratories assessing quality of medical transport devices, including swab transport systems (STS). This study assessed the efficiency of the Sigma Transwab® foam and flock swab in recovering and maintaining viability of different Candida spp. including C. auris, in different test conditions. Both swab types recovered and maintained viability of all Candida spp. with greater CFU at room temperature after incubation (24 and 48 h) in comparison with swabs maintained at 4 °C.

Optimizing a real-time PCR assay for rapid detection of Candida auris in nasal and axillary/groin samples.

Introduction. Candida auris is an emerging fungal pathogen. The organism can cause invasive infections associated with high mortality, has been implicated in outbreaks in healthcare settings and is frequently resistant to multiple antifungal agents, making it a significant challenge to infection prevention and patient treatment.Aim. To implement a real-time PCR assay for detection of C. auris in patient surveillance samples collected with the Copan Liquid Amies elution swab (ESwab) collection and transport system.Methodology. We optimized a real-time PCR testing procedure based on the sample collection device used in our institution.Results . ESwab transport medium was strongly inhibitory to the real-time PCR. Removing the medium with centrifugation, followed by suspending the pellet in PBS-BSA buffer (concentration 1 %), sufficiently eliminated the inhibition. The manual sample preparation method, freeze-thaw followed by mechanical disruption, allowed the detection of C. auris at the lowest cell concentration.Conclusion . The optimized procedure was used to test 1414 patient surveillance samples. The real-time PCR detected all culture-positive samples with 100 % sensitivity and 100 % specificity.

Evaluation of bacterial recovery and viability from three different swab transport systems

This study evaluated three types of swab transport systems for organism recovery. Swabs with transport media were further assessed for organism viability over 24 hours over a range of different storage temperatures. Test organisms consisted of aerobes, fastidious aerobes and anaerobes. Swabs were tested according to the standardised quantitative elution method published by the Clinical Laboratory Standards Institute (CLSI; M-40A). There were substantial differences in primary organism recovery, with recovery rates from different swabs ranging from <0.1% to 78% for Streptococcus pyogenes. Similar differences were noted for other test organisms. In general, the flocked swab (ESwab) demonstrated highest rates of recovery for aerobic organisms, while higher rates of recovery of Fusobacterium nucleatum were demonstrated from a standard swab (Transwab). When considering organism viability, no single swab fulfilled all the criteria stipulated by the M-40A standard for all organism/temperature combinations. Organism viability was marginally better for the gel-based swab transport systems as compared to the liquid-media based ESwab. Significant differences between swab transport systems were demonstrated, including differences for primary organism recovery and viability. The ESwab showed the best recovery of organisms, while gel-based media demonstrated marginally better bacterial viability for most tested retention times and temperatures.

Isolation of Methicillin-resistant Staphylococcus aureus (MRSA) using a flocked swab elution transport system; with identification by PCR

Admission screening is an essential part of the control of methicillin-resistant Staphylococcus aureus (MRSA). Using collection systems that maintain viability and have high organism recovery, combined with accurate and rapid laboratory testing is critical for the success of a screening program. This review evaluates the performance of PCR testing, particularly the Roche LightCycler MRSA test, in the detection of MRSA. In addition, the clinical performance of the Copan Elution swab (ESwab) is reviewed. Several commercial molecular tests developed for use in detecting MRSA colonisation have been evaluated against culture methods, and all appear to provide high sensitivity, good specificity, and the potential for rapid reporting of MRSA colonisation. The new LightCycler MRSA advanced test is another of these assays with rapid detection time and high sensitivity. Compared with the BD GeneOhm MRSA assay, this new test also appears to have improved test specificity. The ESwab has an equal or even better recovery of bacteria, including MRSA, compared with other swab systems, via culture, and PCR. The advantages of using the ESwab are: the use of a liquid Amies medium allowed multiple uses (both culture, and PCR can be performed with one collected sample); and, specimens from multiple sites can be pooled into the same liquid transport media which limits the test costs and broadens the screening capabilities. However, there are limited publications on the clinical performance of the ESwab and more research is required on this new swab transport system.

P5.069 Copan ESwab™, a Liquid Based Microbiology Device, Can Be Used For the Preservation of Neisseria Gonorrhoeae For Culture and For Detection of CT/NG by Gen-Probe ® APTIMA ® COMBO 2 Assay

BackgroundCopan Liquid Amies Elution Swab (ESwab™) Collection and Transport System incorporates maintenance medium which can sustain the viability of Neisseria gonorrhoeae (NG). Swab specimens placed in the tube and stored...

Evaluation of two different swab transport systems in the detection of avian influenza virus excretion from infected Pekin ducks (Anas platyrhynchos)

The role of wild birds in the epidemiology and ecology of influenza A viruses has long been recognised (Alexander, 2007a). As a result of the emergence of a H5N1 highly pathogenic avian influenza (HPAI) virus and the apparent role of wild birds in its spread across Asia, Europe and Africa, avian influenza (AI) wild bird surveillance has been implemented in many countries including, since February 2006, a mandatory programme in the European Union (CEC, 2006a). In the present study the detection of virus excreted from Pekin ducks (Anas platyrhynchos) infected experimentally with A/mallard/England/2126/07 (H3N6) was investigated over a fourteen day period post-infection using cloacal and oropharyngeal swabs, with (wet) and without (dry) viral transport medium which were collected from each duck in alternating order. For influenza A virus matrix gene RNA detection, wet oropharyngeal swabs were significantly more sensitive than dry oropharyngeal on days 4-5 after infection. For cloacal samples, dry swabs were equivalent or superior to wet swabs throughout the study. Although differences in detection between dry and wet swabs were observed, the qualitative bird-level results were unaffected, meaning that the infection status of individual birds was correctly determined.

Evaluation of three swab transport systems for the maintenance of clinically important bacteria in simulated mono- and polymicrobial samples

In this study, three swab transport systems were evaluated: M40 Transystem, Amies broth with a relatively new type of swab (both Copan Diagnostics, Corona, CA, USA), and SSI transportmedium (Statens Serum Institut, Copenhagen Denmark). The CLSI M40-A standard procedures and 11 culture collection strains were used. The transport systems were tested at room temperature for holding times of 0, 24, and 48 h, and both mono- and polymicrobial samples were included. After 24 h of simulated transportation, all systems were able to maintain the viability of all organisms tested. SSI transportmedium exhibited the lowest maintaining ability, whereas the two Copan systems were the most growth-promoting system. In polymicrobial samples, this latter feature was a problem. At 48 h, no transport system could maintain the viability of all strains, and the recovery rates differed depending on organism and device. The species most difficult to recover in all the three systems was Neisseria gonorrhoeae. When selecting a swab transport system, consideration must be given to the sample type, the conditions that prevail locally, and the performance in the clinical setting.

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

An Amies agar gel swab transport system was evaluated for its ability to maintain bacterial viability and relative quantity after freezing at -80°C. Nine American Type Culture Collection (ATCC) bacterial strains were used: 3 anaerobic strains (Propionibacterium acnes, Peptostreptococcus anaerobius, and Clostridium sporogenes) and 6 facultative or strict aerobic bacterial strains (Stenotrophomonas maltophilia, Escherichia coli ([ATCC 25922 and ATCC 11775], Salmonella enterica subsp. enterica serovar Typhimurium, Staphylococcus saprophyticus, and Lactobacillus casei). The bacterial species were chosen because they corresponded to bacteria identified in psittacine feces and cloacal samples. There were no significant differences between growth scores at baseline and after storage at -80°C for 40 days for any of the bacteria examined after 48 and 72 hr of incubation, with the exception of P. anaerobius. For P. anaerobius, there was a significant reduction (P < 0.001) in the growth score after storage at -80°C for 40 days from that of the baseline; however, the bacteria were still viable. The tested swab transport system may be useful when lengthy storage and transport times necessitate freezing samples prior to culture.

Flocked swabs combined with platforms to inoculate and streak specimens: a pre-analytical workstation for microbiology automation

Introduction. The bacteriology processes almost all the clinical specimens through manually performed cultures and therefore needs to evolve toward automated systems.We report our experience on the benefits of combination between liquid-based flocked swab transport systems (Copan Innovation) and platforms of plating and automatic streaking of agar plates.The main innovation is that, for the first time, the automation can be performed not only for urine and other few liquids materials, but also to most of other biological samples. Methods. Our considerations are based on more than one year of experience on the instrument InocuLAB® (Dynacon Inc.) in two Italian Hospitals, supplemented by theoretical knowledge of other marketed in Italy instruments.The three instruments currently available in Italy (A: InocuLAB® Copan, B:WASP® Copan and C: Previ-Isola bioMerieux®) can inoculate and streak liquid or eluated specimens from liquidbased flocked swab transport systems on any agar plate.The main differences are: streaking of already deposited material on plate (only A and B); choice among various protocols of streak and inoculate (only A and B); automatic opening and recapping of the specimen containers (only A and B); automatic choice of the plates (B: 9 columns and C: 5 columns); partition of the streaked plates in groups (B: up to 4 group s and C: up to 3); forced use of disposables devices (only instrument C). No instrument present problems of carryover and the quality of plated specimens is excellent. Conclusions. Although significantly different, all the platforms combined with flocked swabs represent a pre-analytical workstation for microbiology automation (inoculating, streaking, and bar-coding of liquid specimens). The main advantages can be seen in the operator’s production time, in safety and in quality of streak.The almost complete elution of the biological sample in liquid-based flocked swab transport systems is a standard base which allows to perform many diagnostic tests, including quantitative streaking for quantitative evaluation and multiple culture for additional investigation.

Comparison of Copan eSwab with the Copan Venturi Transystem for the quantitative survival of Escherichia coli, Streptococcus agalactiae and Candida albicans

Swab transport systems should preserve the viability and stability of micro-organisms in clinical specimens throughout transport and storage. eSwab, a nylon-tipped swab in liquid medium, designed for better specimen collection and less micro-organism entrapment, was evaluated for the maintenance of viability and quantitative survival of Escherichia coli, Streptococcus agalactiae and Candida albicans. The quantitative elution method was used to evaluate eSwab in vitro. In vitro, the recovery of the three micro-organisms was higher in eSwab (97-100%) as compared to the Copan Venturi Transystem (CVT) (86-96%) at room temperature (RT) for time point 0 h and remained similar after 6 h. E. coli and C. albicans proliferated in both transport systems when preserved beyond 6 h. At 4 degrees C, the recovery of eSwab was higher (>94%) compared to CVT (77-94%) for the micro-organisms tested. eSwab did not only meet the Clinical Laboratory and Standards Institute (CLSI) criteria for microbiological transport devices, but as its recovery rate in vitro was higher than that of CVT, it might also enhance the sensitivity of bacterial culture in the future.

Efficacy of a swab transport system in maintaining long-term viability of Staphylococcus aureus

The noncharcoal liquid Amies swab transport system (Copan, Bovezzo, Italy) can be used for the collection and transport of biologic samples from carriers and infected patients for the detection of strains of Staphylococcus aureus in epidemiologic field studies. We suggest that the maximum holding time, between swab collection and culture, should be 18 days.

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

The ability to directly release 5 aerobic and 5 anaerobic bacterial strains from 3 swab transport systems was evaluated by a time zero roll-plate method. The Copan ESwab (Copan Diagnostics, Murrieta, CA), a new nylon-flocked swab with Amies liquid medium, yielded greater organism release and recovered approximately 10-fold more microorganisms than the Becton Dickinson (Sparks, MD) CultureSwab MaxV and Remel (Lenexa, KS) BactiSwab.

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

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.

Evaluation and comparison of two stuart’s liquid swab transport systems tested by the CLSI M40 method

The Copan Diagnostics HealthLink Transporter swab and the Remel Bacti-Swab were evaluated by the Clinical and Laboratory Standards Institute M40-A quantitative swab elution method for maintenance of bacterial viability of six ATCC and six clinical strains. Acceptable levels of viability according to Clinical and Laboratory Standards Institute criteria were maintained for all organisms tested with the HealthLink Transporter swab and for 8 of 12 organisms tested with the Bacti-Swab. In this study, the HealthLink Transporter swab maintained organism viability better than the Bacti-Swab.

Evaluation of 4 swab transport systems for the recovery of ATCC and clinical strains with characterized resistance mechanisms

Despite limitations of swab transport systems (STS), many clinical samples and bacterial isolates are sent on these devices. We evaluated the performance of 4 commercial STS: M40 Transystem™ (S1, Copan Italia, Bovezzo, Italy), UNI-TER™ (S2, MEUS, Piove di Sacco, Italy), Euromed™ (S3, LAB SERVICE, Surbo, Italy), and Eurotubo™ (S4, Deltalab, Rubí, Spain). Survival of ATCC and clinical strains with characterized resistance mechanisms, stored at room temperature and using the roll-plate method (NCCLS M40-A) after holding times of 0, 6, 24, 48, and 72 h, and 7 days, was assessed. After 24 h, only S1 was able to maintain Streptococcus pneumoniae (ATCC 6305), Haemophilus influenzae (10211), and Neisseria meningitidis (13090) viability with a percentage range of recovery with respect to the baseline count at zero time of 104–184%. Neisseria gonorrhoeae (43069) was uncultivable after 6 h with all STS except S1 (46% recovery). Eighteen percent recovery after 24 h and 7% after 6 h was observed for Fusobacterium nucleatum (25586) and Peptostreptococcus anaerobius (27337), respectively, but only with S1. Resistance mechanisms in clinical isolates do not affect survival with any of the STS.

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

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.

Improved methods of detection of meningococcal DNA from oropharyngeal swabs from cases and contacts of meningococcal disease.

In the UK the increasing use of pre-admission parenteral antibiotic therapy in meningococcal disease has lessened the value of routine cultures as a tool to confirm diagnosis, and laboratory confirmation of invasive meningococcal infection is achieved increasingly by non-culture, nucleic acid amplification methods. The purpose of this study was to evaluate a DNA extraction and meningococcal-specific DNA amplification methodology for detection of meningococci from oropharyngeal swabs. One hundred and six swabs from suspected or confirmed cases of meningococcal disease, and 94 swabs from contacts of meningococcal disease cases were examined. Of laboratory-confirmed cases, 38/65 (58.5%) yielded a positive oropharyngeal swab PCR result and 5/24 (20.8%) swabs from suspected but laboratory-unconfirmed cases were PCR positive. No significant differences in PCR positivity rates were found between the types of swab transport systems utilized, but transport time to the testing laboratory was found to affect PCR positivity (P < 0.05). Application of meningococcus-specific PCR to oropharyngeal swabs, in addition to routine culture of swabs, can provide valuable epidemiological information as well as case confirmation for contact management. PCR amplification of meningococcal PCR from oropharyngeal swabs will also increase the ascertainment in swabbing surveys carried out as part of meningococcal disease outbreak investigation and management.