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Difco™ Listeria O Antisera Types 1, 4 and Poly are used for identifying Listeria monocytogenes in the slide agglutination test.

Difco Listeria O Antigens Types 1 and 4 (Slide) are used as positive controls in the slide agglutination test.

First described in 1926 by Murray, Webb and Swann,¹ Listeria monocytogenes is a widespread problem in public health and the food industries. This organism can cause human illness and death, particularly in immunocompromised individuals and pregnant women.² The first reported foodborne outbreak of listeriosis was in 1985³ and, since then, microbiological and epidemiological evidence from both sporadic and epidemic cases of listeriosis has shown that the principal route of transmission is via the consumption of foodstuffs contaminated with L. monocytogenes.⁴

The organism has been isolated from commercial dairy and other food processing plants and is ubiquitous in nature, being present in a wide-range of unprocessed foods and in soil, sewage, silage and river water.⁵

Listeria spp. grow over a pH range of 4.4-9.6 and survive in food products with pH levels outside these parameters.⁶ Listeria spp. are microaerophilic, gram-positive, asporogenous, non-encapsulated, non-branching, regular, short, motile rods. Motility is most pronounced at 20°C.

Strains of Listeria spp. are divided into serotypes based on cellular (O) and flagellar (H) antigens.⁷ Thirteen serotypes of L. monocytogenes are known. Most human disease is caused by serotypes 1/2a, 1/2b and 4b.⁸

At the time of use, test both positive and negative antigen controls to check performance of the antiserum, techniques and methodology. If results of the positive control or negative control are not as described, the test is invalid and results cannot be reported.

Quality control requirements must be performed in accordance with applicable local, state and/or federal regulations or accreditation requirements and your laboratory's standard Quality Control procedures. It is recommended that the user refer to pertinent CLSI (formerly NCCLS) guidance and CLIA regulations for appropriate Quality Control practices.

Difco Listeria O Antisera Types 1, 4 and Poly are lyophilized, polyclonal rabbit antisera containing approximately 0.1% sodium azide as a preservative. Listeria O Antisera Types 1 and 4 are specific for the respective serotypes of L. monocytogenes while Listeria O Antiserum Poly contains agglutinins for L. monocytogenes serotypes 1 and 4.

Difco Listeria O Antigens Types 1 and 4 (Slide) are suspensions of appropriate L. monocytogenes serotypes containing 0.3% formaldehyde as a preservative. When used according to the suggested procedure, the reagents will yield the following:

For in vitro Diagnostic Use.

The Packaging of This Product Contains Dry Natural Rubber.

Observe aseptic techniques and established precautions against microbiological hazards throughout all procedures. After use, specimens, containers, slides, tubes and other contaminated material must be sterilized by autoclaving. Directions for use should be followed carefully.

WARNING: This product contains sodium azide. Sodium azide is toxic by inhalation, by skin contact, and if swallowed. Contact with acid liberates very toxic gas. After contact with skin, wash immediately with plenty of water. Sodium azide may react with lead and copper plumbing to form highly explosive metal azides. On disposal, flush with a large volume of water to prevent azide build-up.