new products lakewoodbio or lakewood biochemical co., inc

On 11th June, the World Health Organisation raised the alert level for Novel H1N1 virus (Swine Flu) to Phase 6, or pandemic, because of persistent person-to-person transmission in multiple continents.

Already programmes for vaccine production are underway in several countries, but over the next few months as firstly the southern hemisphere enters its influenza season, and then with the predicted surge in cases in the northern autumn and winter, there is a need for continued vigilance and surveillance of influenza virus strains. It is not yet known how stable the genotype will be, and there is the possibility of recombination with the current seasonal flu strain.¹

Various test strategies are being employed in different countries. A number of specific PCR kits are already available, and there is the continued need to submit specimens for full characterisation by cell culture. In these circumstances it is essential to use a reliable specimen collection system, such as Virocult® or Sigma -Virocult®. In fact Medical Wire has a complete range of collection devices, whether required for immediate use and transfer to a kit or system, or for transport at ambient temperatures to a distant reference laboratory.

Virocult®, one of Medical Wire's best known products, is now available for users in the United States.

Virocult® is a virus transport swab suitable for respiratory, skin, genital, ocular and enteric specimens, and is widely used with both traditional cell culture methods, and the more recent molecular techniques.

Virocult® is easy, safe and convenient in use. Each kit consists of a rayon bud swab, and a tube of liquid virus transport medium. The liquid is held in place within a saturated foam pad. There are no separate vials of medium and no swab sticks to break. The product is stored at ambient temperatures with no need for expensive refrigeration. The medium contains antibiotics that prevent the growth of any bacteria or fungi within the specimen (these could interfere with valuable cell cultures or other tests.)

Virocult is suitable for sampling from most body sites, especially epithelial surfaces, such as respiratory or genital areas, or skin lesions. Most of the major viral pathogens have been reported as being recovered such as Herpes Simplex Types 1 and 2, Varicella-Zoster virus, Influenza A and B, mumps, adenovirus, rhinovirus, and various enteroviruses. More recently Virocult has been used in studies about metapneumoviruses.

Virocult® is fully M40-A compliant. CLSI's M40-A Quality Control of Microbiological Transport Systems is often referred to for studies of bacteriology swabs, but there is also an important section on Virus Culture Transport Devices. The standard requires recovery to be tested for holding periods of up to 4 days. Virocult® has been tested against the specified viruses, not only at the recommended titre, but also at lower titres, and was found in all cases to exceed the requirements, both at ambient temperature and at fridge temperatures.

Virocult® is cited by many national and international organisations as a sentinel device to be used for the monitoring of epidemic influenza, including H5N1.

For further information visit our website at www.mwe-usa.com or www.mwe.co.uk.

LINK TO VIROCULT PAGE

∑-Swab™ - The Ideal M40-A Device?

The principal function of a transport swab is to maintain microorganisms in a viable and numerically stable condition. If some organisms die off too rapidly they will not be detectable at the laboratory, but it is also well understood that some bacteria have a tendency to overgrow, even in a well-defined transport medium without nutrients, giving a distorted representation of the relative populations in the original specimens.

CLSI's M40-A standard recognises this problem. It requires that organism numbers should not drop by more than 3 logs during the maximum transport period specified by the manufacturer, whether transport is at ambient or refrigerated temperatures. It also requires that numbers should not increase by more than 1 log during the maximum transport period, but in this case this requirement only applies for transport at refrigerated temperatures.

In some ways this seems a pointless requirement since very few organisms are capable of multiplying at all at low temperatures, and even those which do, such as Listeria will do so relatively slowly. It seems to have been accepted that the overgrowth standard cannot be met at ambient temperatures, although those are the conditions in which many specimens have to be transported.

Medical Wire's new ∑-Swab™ (Sigma Swab) is a dry swab without transport medium which meets the M40-A criteria for keeping bacterial numbers stable at ambient as well as refrigerated temperatures. Studies to be presented in the coming months will show that ∑-Swab™ will keep the numbers of many common organisms stable for 48 hours, neither increasing nor decreasing. These include many of the organisms present in wound infections such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Anaerobes such as Bacteroides fragilis have also been shown to survive in stable numbers for up to 48 hours. Even fastidious organisms will show some limited survival at 24 hours, although for these the assistance of a transport medium would still be recommended.

The secret of ∑-Swab™'s performance is in the bud, which is made from a soft synthetic foam. Unlike conventional swabs with a tightly wound fibre bud, ∑-Swab™'s bud is an open-cell structure. The cells have a uniform icosahedral shape which makes the material highly absorbent, protecting the bacteria within their own micro-environment, yet allowing complete flow-through for reagents for optimum performance for both conventional laboratory procedures, and the many newer molecular methods.

The ability to keep organism numbers stable means that ∑-Swab™ could be the ideal device for many routine specimens such as post-operative wounds, leg ulcers, and MRSA screening.

Using a dry swab has a number of technical advantages. The specimen is not diluted into a transport medium, there are no non-viable bacteria from the medium to interfere with Gram-stains, and there is no overgrowth.

There are also practical and environmental advantages. ∑-Swab™ has a five year shelf-life, since there is no medium to dry out. Tubed dry swabs are considerably less bulky for storage than the peel pouches required for transport swabs, and with less packaging to dispose of. ∑-Swab™ Duo is now also available in a labelled tube.

∑-Swab™ is the ideal specimen collection device for many routine applications, meeting M40-A criteria for survival for many common pathogens, and exceeding the criteria for overgrowth by keeping numbers stable at ambient temperatures. The inert open-celled bud allows improved reactions and sensitivities for conventional and molecular procedures. Extended shelf-life, and reduced packaging assist with stock management and environmental concerns.

Reference
1. CLSI. Quality Control of Microbiological Transport Systems; Approved Standard, CLSI document M40-A [ISBN 1-56238-520-8].

Novel H1N1 Virus - Specimen Collection Resources

Virocult® Now Available in US!

∑-Swab™ - The Ideal M40-A Device?

NRS TRANSWAB Additional info

NRS™ Transwab® for Residual Contamination on Disinfected Food Processing Surfaces

MW775 NRS 10L Transwab, Buffer Liquid, Blue Shaft PK/100 $84.50

STERISWABS ADDITIONAL INFO

MW735/10 Steriswab, Dry, Breakpoint, 10 per Peel Pouch PK/1000 $109.55

MW&E MICROLOOPS

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Acumedia Drymedia

Animal Bloods

Bacteria QC 5 pks

Bacteria QC Sets

Dazzlens Lens Cleaner

Fisher Scientific Website

Labplas Twirl'EM sampling bags

Medical Wire & Equipment

Nasco Whirl-Pak Bags

Prepared Culture Media

Research Biotec Media

Safety Apparel

Gloves, Uniseal

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