Part of Thermo Fisher Scientific
Introduction
The genus Salmonella consists of over 2400 serotypes which may cause
acute infectious gastroenteritis frequently associated with food poisoning.
Since
many Salmonella species infect domestic animals, either clinically
or subclinically, cases of Salmonella food poisoning usually originate
from animal sources. In contrast, Salmonella typhi and Salmonella paratyphi only
infect humans and cause enteric fever. Salmonellae are often present in a
sample in small numbers, together
with other Enterobacteriaceae. In order to promote the growth of Salmonella,
enrichment and/or selective media are used, such as Rappaport Vassiliadis
Medium broths for inducing motility and media containing
selenite, deoxycholate or bismuth sulphite 1,2.
The Oxoid Salmonella
Test Kit is a rapid latex agglutination test for the presumptive identification
of Salmonella in selective and/or enrichment
cultures. The use of latex technology makes this test more sensitive than direct
agglutination
methods, so that use of the Oxoid Salmonella Test Kit permits identification
of Salmonella at least 24 hours earlier than when using conventional
techniques. The Oxoid Salmonella Test Kit is particularly suited to screening
cultures
due to the high predictive value of a negative result. When screening clinical
specimens, these features enable decisions on appropriate patient management
to be taken sooner. The kit is also ideal for screening
samples in the food industry where prompt results minimise the delay associated
with routine testing for Salmonella contamination.
Principle of the Test
Polyvalent antisera are prepared against a wide range of Salmonella flagellar
antigens and used to coat latex particles. When mixed with a suspension of
Salmonella containing these antigens, the latex particles rapidly
agglutinate to form visible clumps. The Oxoid Salmonella Test Kit detects
the majority
of common Salmonella species including Salmonella typhimurium and Salmonella
enteritidis.
In order to minimise cross reactions with other Enterobacteriaceae, antibodies
to the principal somatic antigens are removed during preparation of the antisera.
Consequently, this test reacts predominantly with flagellar
antigens although the reagent will react with the non-motile species Salmonella
pullorumand Salmonella gallinarum.
Components of the Kit.
The reagents supplied are for in vitro diagnostic use only.
Salmonella Latex
Reagent: Latex particles coated with rabbit antiserum against Salmonella antigens,
preserved with 0.02% merthiolate. 2.5 ml
0.85% isotonic saline, preserved with 0.1% sodium azide. 5 ml
Disposable reaction
cards
Disposable mixing sticks
Materials required but not provided
Pasteur pipettes
For full proceedure please see product insert.
References
1. Vassiliadis, P. The Rappaport Vassiliadis (RV) enrichment medium for the
isolation of Salmonellas: an overview. (1983) J. Appl Bacteriol 54,
69 76
2. Sperber, W. and Deibel R.H. Accelerated procedure for Salmonella detection
in dried foods and feeds involving only broth cultures and serological reactions.
(1969) Applied Microbiol. 17, 533 539
3. Ibrahim, G. and Fleet, G.H. Review: Detection of Salmonellae using accelerated
methods. (1985) Int. J. Food Microbiol. 2, 259 272
4. Todd, L.S., Roberts, D., Bartholomew, B.A. and Gilbert, R.J. Assessment
of an enzyme immunoassay for the detection of Salmonellas in foods and animal
feeding stuffs. (1987) Epidem. Inf. 98, 301 310