Gillian A. Jones BSC FIBMS, Robert Human FIBMS

Biography

Gillian A. Jones BSC FIBMS

Gillian Jones is employed in the Microbiology Department at Derriford Hospital as a Senior Biomedical Scientist. Her primary responsibilities are in clinical bacteriology and staff training.

Robert Human FIBMS (not pictured)

Robert Human, having retired from the post of Head Biomedical Scientist at the Microbiology Department, Plymouth Hospitals NHS Trust in 2004, currently acts as an advisory consultant to Pathcare Doublesure, a large multinational company.

The hospital delivers a wide range of general and specialist services to a local population of 460,000 that includes cardiothoracic surgery and cardiology, neurosurgery and neurology, renal transplant surgery, some specialist cancer treatments, plastic surgery and burns. It has 1100 beds and employs around 6000 staff. The department employs 50 staff and provides a clinical diagnostic service that includes molecular biology and an environmental health service to its users and processes 340,000 specimens per annum.

Their work with swab transport systems started in 1986 with the publication of a paper on the survival of bacteria in swab transport packs. Since that time, papers have been published and presented at national and international meetings. They have continued to monitor the development of new and emerging swab designs in an effort to better advise their profession on swab performance.

Bacteriology, Electron Microscopy and Radioisotopes: an Evaluation in Determining Swab Structure, Absorption and Release

Background

The use of cotton wool swabs for the transport of bacteria was first reported in 1893. Since that time there have been few changes apart from the use of gel transport medium in the 1940s. Copan Italia has introduced a new concept: the use of flocked nylon fibre pile swabs in 1ml Amies medium.

Method

The flocked swab was evaluated against the existing wound Copan Italia M40 product by: a) quantitative and qualitative viable counts of a range of bacteria after varying storage times and temperatures, b) scanning electron microscopy and c) the use of radioactive tracer Cr51 to gauge absorption and release of particles.

Results

Quantitative studies of the bacteria once released by the flocked swab into the liquid Amies showed good results with less than a 3 log10 reduction. Recovery of all strains improved when stored at 4-8ºC. Scanning electron microscopy showed the configuration of the M40 fibres being a dense matrix and the flocked an open brush-like network. Results from the use of liquid Cr51 EDTA demonstrated that the flocked swab released a larger amount than the M40 product.

Conclusion

Although there is good bacterial survival in the M40 product, the flocked swab plus Amies has shown either equivalent or improved recovery of the bacterial strains tested. Protein binding is higher with nylon of the flocked swab, which may be reflected in the electron micrographs and increased release of microorganisms. This new revolutionary product by Copan also has the advantage that 1ml of Amies is available to inoculate a number of culture plates and sufficient material is available for automatic processing or the use of molecular techniques such as the detection of MRSA.