Kauffmann-White scheme
The Kauffmann-White scheme (currently correct but unusual name: White-Kauffmann-Le Minor scheme) is a classification system used in bacteriology for representatives of the enterobacteria - genus Salmonella . It allows the serological classification of varieties and serotypes (also called “serovars”). In the complete Kauffmann-White scheme, over 2500 different serovars of Salmonella are classified. Salmonella, which are closely related to species in the genus Escherichia , are pathogens and can infect both animals and humans through the food chain . Infectious diseases with this transmission route are also known as zoonoses .
history
In 1880 Karl Joseph Eberth and Robert Koch discovered the causative agent of human typhoid (at that time Eberthella typhosa , today called Salmonella typhi ), in 1885 Daniel Elmer identified Salmon , after whom the genus Salmonella was named, the causative agent of "pig cholera" ( S. choleraesuis ). Other Salmonella species ( e.g. S. typhimurium (mouse typhus) and S. abortusovis ( abortion of sheep)) were found in animals . With the classic methods of microbiology - for example biochemical characteristics such as differences in the utilization of different sugars (see also Bunte Reihe ) - these pathogens could not be distinguished from one another due to their close relationship. A classification of this group of pathogens was only possible on the basis of serological characteristics.
In 1926 the British bacteriologist Philip Bruce White published a scheme for the classification of salmonella on a serological basis, which was developed and expanded by the Danish bacteriologist Fritz Kauffmann from 1933 to 1978. This expansion is still taking place today, and the French bacteriologist Michel Popoff publishes an update of the scheme every few years . The last update was published in 2007. Between ten and 20 new serotypes are recorded and described annually in these updates. In collaboration with the World Health Organization , Popoff publishes updated Kauffmann-White schemes in book form at longer intervals.
Salmonella nomenclature
See also: main article Salmonella
The nomenclature of the Salmonella species is very complex. First, Salmonella was named according to clinical criteria (name of the disease and the host ). When it was recognized that the host specificity of some species did not exist - S. typhimurium and S. choleraesuis are also pathogenic for humans - new serovars were named as independent Salmonella species after the place where the first strain of the new species was isolated. In 2005, the Judicial Commission of the International Committee on Systematics of Prokaryotes (ICSP) decided that the genus Salmonella consists of two species, S. enterica and S. bongori , with S. enterica divided into numerous subspecies .
This formal nomenclature, created by microbiological systematists , is not in accordance with the traditional systematics of the Salmonella species and with the Kauffmann species name due to the serovars. However, microbiologists and infectiologists have been familiar with this naming principle for decades, so this actually incorrect nomenclature is still widespread today and is also used in the examples in the following article.
Basics of the Kauffmann-White scheme
The principle of the Kauffmann-White scheme
When creating a Kauffmann-White scheme with, for example, three different Salmonella strains, three antisera directed against these strains are available as detection reagents. In a first series of experiments, the reactions of the antisera against the respective original strain and against the two other strains are quantified. In a second series of experiments, the antisera are pretreated with the non-homologous strains before quantification. This pre-treatment is also called pre- adsorption . The test results are summarized in a table (4+: strong; 2+: medium; 0: no reaction):
| Antisera | Strain 1 | Trunk 2 | Trunk 3 |
|---|---|---|---|
| Anti-1, not adsorbed | 4+ | 2+ | 4+ |
| Anti-2, not adsorbed | 2+ | 4+ | 2+ |
| Anti-3, not adsorbed | 4+ | 2+ | 4+ |
| Anti-1 adsorbed on strain 2 | 2+ | 0 | 2+ |
| Anti-1 adsorbed on strain 3 | 2+ | 0 | 2+ |
| Anti-2 adsorbed on strain 1 | 0 | 2+ | 0 |
| Anti-2 adsorbed on strain 3 | 0 | 2+ | 0 |
| Anti-3 adsorbed on strain 1 | 2+ | 0 | 2+ |
| Anti-3 adsorbed on strain 2 | 0 | 2+ | 0 |
There are differences, but also similarities between the three strains, strain 1 and 3 show identical reaction patterns and are therefore serologically identical. Strains 1 and 3 have both similarities and differences with respect to strain 2, so one could assign the determinants (or factors) A and B to strains 1 and 3 in an artificial system, and strain 2 the determinants B and C. One could however, these factors also use the Greek letters α, β, and γ in an alternative scheme. Should a newly discovered Salmonella strain with a different, completely new type of antigen pattern be included in this system, the extended scheme will look like this:
| Antisera | Strain 1 | Trunk 2 | Trunk 3 | Trunk 4 |
|---|---|---|---|---|
| Anti-1, not adsorbed | 4+ | 2+ | 4+ | 0 |
| Anti-2, not adsorbed | 2+ | 4+ | 2+ | 0 |
| Anti-3, not adsorbed | 4+ | 2+ | 4+ | 0 |
| Anti-4, not adsorbed | 0 | 0 | 0 | 4+ |
| Anti-1 adsorbed on strain 2 | 2+ | 0 | 2+ | 0 |
| Anti-1 adsorbed on strain 3 | 2+ | 0 | 2+ | 0 |
| Anti-1 adsorbed on strain 4 | 0 | 0 | 0 | 2+ |
| Anti-2 adsorbed on strain 1 | 0 | 2+ | 0 | 0 |
| Anti-2 adsorbed on strain 3 | 0 | 2+ | 0 | 0 |
| Anti-2 adsorbed on strain 4 | 0 | 0 | 0 | 2+ |
| Anti-3 adsorbed on strain 1 | 2+ | 0 | 2+ | 0 |
| Anti-3 adsorbed on strain 2 | 0 | 2+ | 0 | 0 |
| Anti-4 adsorbed on strain 4 | 0 | 0 | 0 | 2+ |
| Anti-4 adsorbed on strain 1 | 0 | 0 | 0 | 2+ |
| Anti-4 adsorbed on strain 2 | 0 | 0 | 0 | 2+ |
| Anti-4. adsorbed on strain 3 | 0 | 0 | 0 | 2+ |
Since the antigens of strain 4 do not show any cross-reactions with any antigen of strains 1 to 3, this strain is assigned the determinant D (or δ in the alternative scheme) in this hypothetical scheme. Further newly isolated strains with differing antigen patterns can be integrated into this scheme.
The Kauffmann-White scheme is ultimately based on the empirical evaluation of antigen-antibody cross-reactions of pre - adsorbed antisera with the surface antigens of a Salmonella strain.
Name and nature of the antigens
Salmonella has three different surface antigens called the H , O and Vi antigens. When these names were introduced, nothing was known about the function and exact location of these antigens.
The designation H was first used to describe the swarming behavior of Proteus mirabilis . In semi-solid agar , P. mirabilis and also Salmonella move quickly thanks to their peritrichal (i.e. distributed over the entire cell surface) flagella.The appearance of a swarming colony also resembles an H that human breath leaves in the form of water droplets when you breathe on a glass plate. H antibodies are directed against the flagella proteins. Most Salmonella serovars have two different types of flagellum antigens. These are also known as phases . There is mainly one phase in a single colony. A change from one to the other takes place in this clone with a frequency of 10 −3 to 10 −5 . This means:
- One in a hundred or one in ten thousand cells in a colony switches to the other phase.
- The phenotype of the single cell is monophasic, while the genotype and population are biphasic. Only a few serovars (e.g. Salmonella Enteritidis, Salmonella Typhi) are exclusively monophasic, i.e. they have only one flagellum antigen. The H antigens of the first phase are labeled with letters, those of the second phase with Arabic numerals, and rarely letters.
The O was originally only for o teeth touch, it means these bacteria not rave on an agar plate. The O antigens were first found in non-flagellated bacterial strains. O antibodies are directed against the lipopolysaccharides on the cell surface. A distinction is made between main O antigens, which determine the group membership of the serovars, and minor O antigens. The minor O antigens are mostly found in many serovars (for example, all Salmonella strains from O groups A, B, and D have the antigen O: 12) and are therefore of little importance for classification purposes.
The name Vi represents an additional surface antigen, which initially primarily for Vi rulenz was blamed; however, it provides a special case of K Apsel represents antigen are. The lipopolysaccharide O-antigen containing coated with the thin layer of the Vi antigen, a polysaccharide. Vi antigens are only found in Salmonella Typhi, Salmonella Paratyphi C and Salmonella Dublin and prevent the bacteria from reacting with O antibodies.
Practical implementation of the antigen-antibody reactions
Before carrying out the antigen-antibody reactions, preliminary tests are carried out to check whether non-specific agglutinations are taking place. For this purpose, some bacterial material is rubbed in physiological saline solution on a slide and the suspension is observed against a black background (black construction paper , black tile). If the suspension remains milky for about 5 minutes, no spontaneous agglutination takes place. To ensure that a Salmonella strain is actually being used, a positive control against O-antigens can be carried out with an omnivalent antiserum (an antiserum that recognizes all antigens) . To do this, some bacterial material is rubbed in with the antiserum. After about two minutes, clearly visible agglutinates should appear on a black background. This procedure is called slide agglutination .
In the following determination, group membership is first determined with the aid of group-specific O-antigens in the slide agglutination. Then the flagellar phase is determined with the help of the H-antisera with the slide agglutination. There is a difference here: the antigen-antibody aggregates are solid and granular with the O-antigen, while with the H-antigen they are flaky and not very stable. Once the first phase of the H antigen has been determined, the second phase is determined. For this purpose, a swarm plate is made that contains the corresponding H-antiserum. This suppresses the swarming of bacteria belonging to the first phase. Only those who have switched to the second phase can move under these conditions. After overnight incubation, bacterial material from the swarming zone can be used to determine the second phase by agglutination with suitable H antisera.
The serovar of the present Salmonella strain can be determined from the Kauffmann-White scheme from the combination of O antigens and H antigens of the first and second phases . See also
A simple Kauffmann-White scheme
In the following table, some important Salmonella serovars are classified according to the Kauffmann-White scheme, using the classic nomenclature:
| "O" group | Serovar | "O" antigens | "H" antigens phase 1 | "H" antigens phase 2 |
|---|---|---|---|---|
| Group A | Salmonella paratyphi A | 1, 2, 12 | A. | no phase 2 |
| Group B | Salmonella paratyphi B | 1, 4, 5, 12 | B. | 1, 2 |
| Group B | Salmonella Typhimurium | 1, 4, 5, 12 | I. | 1, 2 |
| Group B | Salmonella Abortusovis | 4, 12 | C. | 1.6 |
| Group C | Salmonella Choleraesuis | 6, 7 | C. | 1.5 |
| Group C | Salmonella Thompson | 6, 7 | K | 1, 5 |
| Group C | Salmonella Newport | 6, 8 | R. | 1, 5 |
| Group C | Salmonella Munich | 6, 8 | D. | 1, 2 |
| Group D | Salmonella Typhi | 9, 12 | D. | no phase 2 |
| Group D | Salmonella Enteritidis | 1, 9, 12 | g, m | no phase 2 |
| Group D | Salmonella Dublin | 1, 9, 12 | 91 p | no phase 2 |
| Group E | Salmonella anatum | 3, 10 | e, h | 1, 6 |
Choice of antisera
It takes a lot of effort to establish and maintain a full stock of antisera to run a complete Kauffmann-White scheme. This is mainly done in national reference laboratories. Most laboratories only keep a certain number of antisera in stock, with the selection of antisera based on the salmonella serovars that are likely to be processed. In order to achieve results that are comparable between the laboratories, the WHO has prescribed standards for the production of the antisera.
A common selection looks like this:
| O-Antisera | H antisera |
|---|---|
| Polyvalent-O, Groups A-G | Polyvalent-H, specific and unspecific |
| 2-O, group A | Polyvalent-H, unspecific factors 1,2,5,6,7 |
| 4-O, group B | aH ( Salmonella Paratyphi A) |
| 6, 7-O, group C1 | bH ( Salmonella Paratyphi B) |
| 8-O, group C2 | cH ( Salmonella Paratyphi C) |
| 9-O, Group D | dH ( Salmonella Typhi) |
| 3, 10, 15, 19-O Group E | e, hH ( Salmonella Newport) |
| 11-O, group F | f, gH ( Salmonella Derby) |
| 13, 22-O, group G | g, mH ( Salmonella Enteritidis) |
| iH ( Salmonella Typhimurium) | |
| kH ( Salmonella Thompson) | |
| l, vH ( Salmonella London) | |
| m, tH ( Salmonella Oranienburg) | |
| rH ( Salmonella Bovismorbificans) |
Laboratories that deal with typhoid pathogens also have antisera against Vi antigens available.
A phrase "Schnelldiagnostiksera" ( rapid diagnostic sera or RDS ) is also used: It is used for the determination of frequently occurring H antigens with the exception of iH. If the agglutination with a polyvalent H-specific antiserum (an antiserum that recognizes several H antigens) and an unspecific antiserum is positive, the three RDS antisera are used to identify the H antigen. The respective H antigen can be determined from the agglutination-nonagglutination pattern.
| antigen | RDS1 | RDS2 | RDS3 |
|---|---|---|---|
| b | agglutination | agglutination | no agglutination |
| d | agglutination | no agglutination | agglutination |
| E. | agglutination | agglutination | agglutination |
| G | no agglutination | no agglutination | agglutination |
| k | no agglutination | agglutination | agglutination |
| L. | no agglutination | agglutination | no agglutination |
| r | agglutination | no agglutination | no agglutination |
- E = polyvalent for the antigens eh, enx, etc .
- G = polyvalent for the antigens gm, gp, etc .
- L = polyvalent for the antigens lv, lw, etc .
Recent developments
The conventional method for determining the composition of the surface antigens is time and material consuming. Simultaneous detection of O and H antigens is desirable. For this purpose, antibodies selected according to the Kauffmann-White scheme were applied to a microscope slide in a protein microarray and Salmonella cells marked with fluorescent dyes were treated. However, this miniaturization is not yet routine in the diagnostic laboratory.
literature
- Patrick AD Grimont & François-Xavier Weill: Antigenic Form of the Salmonella Serovars (English) 9th edition. 2007, published by the WHO Collaborating Center for Reference and Research on Salmonella and the Pasteur Institute
Web links
- Website of the national reference center for salmonella and other bacterial enteritis pathogens, RKI area Wernigerode
Individual evidence
- ^ PB White: Further Studies of the Salmonella Group . Great Britain Medical Research Council 103, (Her Majesty's Stationary Office), 3-160, 1926.
- ^ F. Kauffmann: Das Fundament , Munksgaard, Copenhagen, 1978.
- ^ MY Popoff, J. Bockemühl, LL Gheesling: Supplement 2002 (no. 46) to the Kauffmann-White scheme. In: Research in microbiology. Volume 155, Number 7, September 2004, pp. 568-570, ISSN 0923-2508 . doi: 10.1016 / j.resmic.2004.04.005 . PMID 15313257 .
- ^ MY Popoff: Antigenic formulas of the Salmonella serovars . 8th ed. World Health Organization Collaborating Center for Reference and Research on Salmonella, Institut Pasteur, Paris, 2001
- ^ Judicial Commission of the International Committee on Systematics of Prokaryotes. The type species of the genus Salmonella Lignieres 1900 is Salmonella enterica (ex Kauffmann and Edwards 1952) Le Minor and Popoff 1987, with the type strain LT2T, and conservation of the epithet enterica in Salmonella enterica over all earlier epithets that may be applied to this species. Opinion 80. In: International journal of systematic and evolutionary microbiology. Volume 55, Pt 1 January 2005, pp. 519-520, ISSN 1466-5026 . doi: 10.1099 / ijs.0.63579-0 . PMID 15653929 .
- ^ BJ Tindall, PA Grimont, GM Garrity, JP Euzéby: Nomenclature and taxonomy of the genus Salmonella. In: International journal of systematic and evolutionary microbiology. Volume 55, Pt 1 January 2005, pp. 521-524, ISSN 1466-5026 . doi: 10.1099 / ijs.0.63580-0 . PMID 15653930 .
- ↑ Ruhr-Universität Bochum: Script for the practical implementation of the antigen-antibody reactions ( Memento from February 8, 2008 in the Internet Archive )
- ^ MY Popoff: Guidelines for the preparation of Salmonella antisera . 5th ed. World Health Organization Collaborating Center for Reference and Research on Salmonella, Institut Pasteur, Paris 2002
- ↑ Development of a novel protein microarray method for serotyping Salmonella enterica strains. In: Journal of clinical microbiology. Volume 43, Number 7, July 2005, pp. 3427-3430, ISSN 0095-1137 . doi: 10.1128 / JCM.43.7.3427-3430.2005 . PMID 16000469 . PMC 1169117 (free full text).
