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EP1009803A1 - Enrichissement selectif et detection de micro-organismes - Google Patents

Enrichissement selectif et detection de micro-organismes

Info

Publication number
EP1009803A1
EP1009803A1 EP98932406A EP98932406A EP1009803A1 EP 1009803 A1 EP1009803 A1 EP 1009803A1 EP 98932406 A EP98932406 A EP 98932406A EP 98932406 A EP98932406 A EP 98932406A EP 1009803 A1 EP1009803 A1 EP 1009803A1
Authority
EP
European Patent Office
Prior art keywords
enrichment
sample
medium
selective
oxyrase
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98932406A
Other languages
German (de)
English (en)
Inventor
Peter Jeremy Stephens
Roy Holbrook
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oxoid Ltd
Original Assignee
Oxoid Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9714594.0A external-priority patent/GB9714594D0/en
Application filed by Oxoid Ltd filed Critical Oxoid Ltd
Priority to EP98932406A priority Critical patent/EP1009803A1/fr
Publication of EP1009803A1 publication Critical patent/EP1009803A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/02—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving viable microorganisms
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
    • C12N1/20—Bacteria; Culture media therefor
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/25—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving enzymes not classifiable in groups C12Q1/26 - C12Q1/66

Definitions

  • This invention relates to the detection of microorganisms, for example in food samples, and particularly concerns a method of enriching the population of a target microorganism in a sample, and ingredients for use in such a method.
  • a typical conventional technique for detecting a target microorganism of interest involves incubating a sample in a pre-enrichment broth, commonly buffered peptone water (BPW) for 18 to 24 hours under conditions which encourage microorganism recovery and growth, so that any organisms present can proliferate in the sample and attain population levels which are more readily detectable.
  • This step is known as a pre- enrichment, recovery or resuscitation step.
  • Portions of the pre-enrichment culture are then subcultured into selective enrichment broths and incubated for a further 20 to 24 hours.
  • the selective enrichment broths are designed to inhibit growth of comparatively innocuous non-target microorganisms and so favour the growth of the target microorganisms. This step is known as a selective enrichment step.
  • Figure 1 is a simplified schematic graph illustrating the variation in cell numbers with time during the pre-enrichment step (0 to 24 hours) and the enrichment step (24 to 48 hours) of a target organism ⁇ Salmonella) and non-target, competitor organisms.
  • the target organisms are then identified.
  • Conventional processing involves subculturing enrichment broths onto selective differential agar plates and incubating for 20 to 24 hours. Suspected colonies of target organism are identified by visual examination, and selected suspected colonies are removed from the plates, purified and identified, eg using triple sugar iron (TSI) agar and lysine iron (LSI) agar slopes and serological tests. Purification, identification and confirmation can take up to 48 hours.
  • TSI triple sugar iron
  • LSI lysine iron
  • Figure 2 is a schematic representation of such a conventional method for detection of Salmonella in foods.
  • Pre-enrichment is designed to perform many functions, including maintenance of neutral pH, bom against the effect of the food material and the acid produced by growth of competing bacteria, and ensuring that the level of growth of the target species is sufficient to guarantee transfer and growth upon subsequent subculture to the selective enrichment broth.
  • the most important role of pre-enrichment is in supporting the resuscitation of cells of the target microorganism that maybe in a debilitated state. Without some provision to rejuvenate such stressed or damaged cells, the selective conditions required in the culture isolation procedure could render these bacteria undetectable. Such an occurrence could have serious consequences since even low levels of organisms such as Salmonella have been known to cause infection.
  • the present invention concerns a method of enriching the population of a target microorganism in a sample, comprising incubating the sample in a pre-enrichment medium, with one or more selective agents to favour growth of the target microorganism arranged for release into the medium after a predetermined time delay.
  • the method of the invention combines pre-enrichment and selective enrichment steps by use of timed release of the selective agent(s).
  • the selective agents(s) are released in automated manner, in a way that does not require operator intervention. This has the benefits of reducing the amount of manipulation and labour necessary for these stages, and also of reducing the amount of time required for these stages. It has been found that these stages can be satisfactorily completed within 24 hours, without the need for operator intervention.
  • the enrichment can be followed by identification of the target microorganism, using any appropriate technique, either conventional or rapid, as outlined above. Using rapid identification techniques, total test time can be reduced to a little over 24 hours, and further time reductions may become possible.
  • the invention finds particular application in the analysis of samples of foodstuffs and beverages in the enrichment and identification of a wide range of foodborne pathogens including Salmonella, Liste ⁇ a, Camp lobacter and E. coli 0157, but can also be used in connection with a wider range of target organisms from a much wider range of sample types, including environmental samples.
  • the pre-enrichment medium conveniently comprises peptone.
  • the peptone is preferably selected for optimised recovery of stressed or damaged cells of the target microorganism.
  • the peptone is preferably generally as described in the specification of our copending British Patent Application No. 9721396.1 (pursued in a PCT application).
  • the pre-enrichment medium desirably includes one or more recovery agents to aid recovery of stressed or damaged cells of the target microorganism.
  • the currently preferred recovery agent is OXYRASE enzyme, which is made from sterilised bacterial membrane fragments, and which is known to be an effective oxygen-reducing enzyme used to produce anaerobic conditions.
  • OXYRASE enzyme is described in technical bulletins distributed by Oxyrase, Inc. of Ohio and is further described by Adler et al. in J. Bacteriology, August 1981, 326-332, and in a paper by H.I Adler in Critical Reviews of Biotechnology 10: 118 (1990) entitled "The Use of Microbial Membranes to Achieve Anaerobiosis". See also US Patents Nos.
  • OXYRASE is a trade mark of Oxyrase, Inc, from whom OXYRASE enzyme is available.
  • Oxyrase, Inc from whom OXYRASE enzyme is available.
  • a similar enzyme system derived from irradiated microorganisms is described in EP 0520757 of Becton Dickinson.
  • peptones are probably contributing the lowest level of toxic oxidising species, eg hydrogen peroxide, hydroxyl radicals, superoxide anions and singlet oxygen, to the medium, possibly generated by exposure to oxygen, light and/or high temperatures, eg on autoclaving.
  • toxic oxidising species eg hydrogen peroxide, hydroxyl radicals, superoxide anions and singlet oxygen
  • OXYRASE causes the cells to grow anaerobically thus bypassing any internal pathways that produce toxic oxidising species such as hydrogen peroxide.
  • OXYRASE also contains catalase which removes external hydrogen peroxide which is why when it is added to poor peptones at high concentrations it is still effective at improving recovery. Additionally, free nucleic acid and lip id material in the OXYRASE preparation may absorb toxic oxidising species.
  • Anaerobic conditions can alternatively be achieved by physical means either using anaerobic jars, roll mbes (eg. the Hungate technique) or anaerobic cabinets. The latter two methods are likely to give similar improvements to use of recovery agents such as OXYRASE.
  • Sphingosine type selective agents may optionally be added as supplements to the pre- enrichment medium.
  • reducing agents act to reduce the efficacy of recovery agents such as OXYRASE.
  • This can be overcome by adding to samples containing or suspected to contain significant quantities of preservatives, such as sausages, neutralising agents such as pyruvate, alpha ketoglutaric acid, acetaldehyde, maltose, glucose, etc, which convert the reducing agent to a non-reactive form.
  • the selective agent(s) for delayed release may be chosen from a wide range of possibilities, having regard to the target organism, as is known to those skilled in the art. Good results have been obtained with selective agents based on the traditional Rappaport- Vassiliadis (RV) broth, including magnesium chloride and malachite green. Similar results may be expected using one or more other traditional selective agents such as dyes, selenite cystine, tetrathionate and antibiotics. Suitable concentrations of such materials are known to those skilled in the art, or can be readily determined by experiment.
  • Timed release of the selective agent(s) into the pre-enrichment medium is conveniently achieved by incorporating the selective agent(s) in suitable timed-release capsules.
  • the currently preferred capsule is generally as described in WO95/ 10263, and comprises an insoluble plastics capsule body with a male hydrogel plug. When the capsule is exposed to an aqueous medium the hydrogel plug swells slowly and eventually disengages, releasing the capsule contents, after a predetermined time interval that is controllable and predictable.
  • Suitable capsules of this construction are available from Scherer DDS under the name PULSINCAP (PULSINCAP is a Trade Mark).
  • the time delay before release of the selective agents is chosen having regard to the target organism. It is necessary to try to achieve maximum recovery of target cells before overgrowth of non-target competitors.
  • Factors such as ingredients, time delay and incubation temperature are tailored to the particular target organism.
  • Salmonella for example, good results have been obtained by incubation in pre-enrichment medium of optimised peptone with OXYRASE recovery agent, with Rappaport-Vassiliadis selective agents in size "O" PULSINCAP capsules designed to release their contents after 5 hours.
  • the materials are suitably placed in an incubator at 42 ⁇ 1°C and incubated on a shaking platform at 90 rpm for 24 + 1 hours.
  • Rappaport-Vassiliadis (RN) selective agents which are believed to be the best of those in current use, requires reduction of the pH of the medium to 5.2 upon capsule release to achieve sufficiently selective conditions.
  • both the capsule content formulation and the pre-enrichment medium have been manipulated.
  • the key selective properties of RN are brought about by its high magnesium chloride content, malachite green, a pH of 5.2 and an incubation temperature of 41.5- 42.0 °C.
  • the other components of RV such as the phosphate buffer, sodium chloride and peptone are not required in the capsule formulation because they are preferably already present in the preferred pre-enrichment medium.
  • capsule release of magnesium chloride does not naturally reduce the pH to a sufficient extent. For this reason, extra acid is preferably added to the capsule, conveniently in the form of malic acid. Malic acid is favoured because it is already frequently used in culture media to adjust pH. Without reducing the buffering capacity of the pre-enrichment medium it would not be possible to fit all the required malic acid into a reasonable number of capsules, conveniently 6 capsules. It was discovered that a small portion of the magnesium chloride could be included in the pre-enrichment medium without damaging its recovery capability, thus providing more space in the capsules for malic acid. It was still necessary to reduce the buffering capacity of the pre-enrichment medium to limit the amount of malic acid to 0.8g per litre. Approximately 0.6g per litre of magnesium chloride was removed from the total test formulation without affecting selectivity.
  • Reducing the buffering capacity of the pre-enrichment medium is not a concern because of me shortened non-selective period for growth of organisms that may influence the pH of the medium.
  • the medium still retains sufficient capacity to cope with the pH influence of the food material in the majority of samples. Foods with extreme pHs will require the broth pH to be adjusted to 7.0 by the addition of acid or alkali before the test is initiated.
  • Additional malachite green is preferably included in the capsule formulation when compared to the traditional RN formulation. This is to overcome any absorption of dye by the food material that is now present throughout the test period. The higher concentration of malachite green has been shown not to be toxic to dye-sensitive Salmonella strains.
  • an incubation temperature of 41.5 - 42.0°C is also critical to achieving sufficient selectivity to prevent overgrowth of competing organisms. Direct inoculation of samples into a broth at this temperature, however, is detrimental to the recovery of stressed cells. To overcome this it is convenient to use a gradual temperature increase brought about by controlling the temperature of the broth prior to incubation.
  • Campylobacter it may be necessary to incorporate some selective agents from the start of the test to overcome particularly acute forms of the Jameson Effect.
  • Possible selective agents for Campylobacter include: (at time zero) cefperaxone, amphotericin, trimethoprim, and (delayed addition) polymixin and rifampicin.
  • suitable selective agents for time-delayed delivery include bile salts and novobiocin and/or a combination of the following antibiotics: vancomycin, cefixime, cefsulodin and acriflavin.
  • the medium could also include rhamnose or tellurite. All of these are currently used in selective media for the isolation and detection of E. coli 0157.
  • suitable selective agents for delayed addition include: nalidixic acid, acriflavine and cyclohexamide.
  • ferric ammonium citrate to the pre-enrichment medium may be appropriate to aid growth of Liste ⁇ a.
  • the temperature of incubation may need to be varied for these other foodborne pathogens.
  • a chromogen may optionally be included in the test to give a colour reaction that could be measured at the end of the test to indicate the presence of absence of a particular organism.
  • the present invention provides a method of enriching the population of Salmonella in a sample, comprising incubating the sample in a pre-enrichment medium comprising peptone and OXYRASE, with one or more timed-release capsules containing Rappaport-Vassiliadis selective agents and malic acid, the capsules being arranged to release their contents approximately 5 hours after contact with aqueous medium, incubation being carried out for approximately 24 hours at a temperature rising to approximately 42°C.
  • the present invention provides ingredients for use in enriching the population of a target microorganism in a sample, comprising a timed-release capsule containing one or more selective agents to favour growth of the target microorganism.
  • the ingredients preferably further comprise a supply of pre-enrichment medium, desirably comprising peptone with optional recovery agent, preferably OXYRASE.
  • pre-enrichment medium desirably comprising peptone with optional recovery agent, preferably OXYRASE.
  • OXYRASE is preferably in freeze-dried form.
  • the pre-enriched medium preferably includes a hydrogen donor in sufficient amount for optimum functioning of the enzymes contained in OXYRASE.
  • Suitable hydrogen donors include lactic acid, succinic acid, formic acid, alpha glycerol phosphate and their salts.
  • a millimolar concentration of the hydrogen donor is generally ample to remove all dissolved oxygen.
  • Figure 1 is a simplified, schematic graph of cell numbers versus time
  • Figure 2 is a schematic representation of a conventional method for detection of Salmonella in foods
  • Figure 3 is a schematic sectional view of a delayed timed-release capsule
  • Figure 4 is a chart of the release time of a number of capsules as shown in Figure 3.
  • Figure 5 is a graph of temperature versus time, showing the temperature profile over 24 hours of a stomacher bag in an incubator set at 42 °C.
  • a product for use in enriching Salmonella in food samples comprises a pot containing 500g of dehydrated modified pre-enrichment medium (which is sufficient for about 100 tests), a vial of freeze-dried OXYRASE and a pack of 6 timed-release capsules containing selective agents.
  • the vial contains about 50 units of OXYRASE (as measured according to the method described in the OXYRASE product literature) which is an appropriate amount for 1 test.
  • the pot of enrichment broth will be sold separately.
  • a kit containing enough OXYRASE and capsules for 20 tests, ie 20 vials of OXYRASE and 20 packs of 6 capsules, will be available separately.
  • the pre-enrichment medium is generally as described in GB 9721396.1 (with the addition of magnesium chloride, and with reduced buffering capacity), and is intended to be dissolved in distilled water in the amount of 4.275g of medium in 225 ml of water to produce a broth having the following composition:
  • the peptone component of the pre-enrichment broth formulation is a meat based product comprising:
  • the riboflavin content of the pre-enrichment medium was measured by the technique described in Example 3 of GB 9721396.1, and was determined to be 0.045 mg/1.
  • the hydrogen peroxide equivalent was measured by the technique described in Example 4 of GB 9721396.1, and was determined to be 0.021mM.
  • the freeze-dried OXYRASE enzyme was produced by freeze-drying in known manner OXYRASE enzyme obtained from Oxyrase, Inc. , after removal of succinate and lactate if present.
  • the capsules are "O" size PULSINCAP capsules, as illustrated in Figure 3.
  • the illustrated capsule comprises a generally cylindrical capsule body 10 of insoluble plastics containing a hard compacted cylindrical slug 12 of selective agents weighing 570 mg, the slug being 11mm in length and 6mm in diameter.
  • the capsule is closed by a male hydrogel plug 14, 3.2mm long.
  • FIG. 4 is a chart of the time of plug release for 72 such capsules incubated at 42 °C with shaking at 90 rpm in the presence of a range of different foodstuffs, demonstrating plug release in this time window for the vast majority of capsules tested.
  • Each capsule contains the following selective agent formulation: grams Magnesium chloride (anhydrous) 0.5325
  • the selective agents are based on Rappaport-Nassiliadis selective agents, and require reduction of the pH of the medium to 5.2 upon capsule release to achieve sufficiently selective conditions. In order to achieve this it was necessary to manipulate both the capsule content formulation and the pre-enrichment medium.
  • the key selective properties of RN are brought about by its high magnesium chloride content, malachite green, a pH of 5.2 and an incubation temperature of 41.5 - 42.0°C.
  • the other components of RN such as the phosphate buffer, sodium chloride and peptone are not included in the capsule formulation because they are already present in the modified pre-enrichment medium.
  • the capsule release of magnesium chloride does not reduce the pH to a sufficiently low level without adding extra acid, in the form of malic acid.
  • Malic acid was chosen because it is already frequently used in culture media to adjust pH. Without reducing the buffering capacity of the pre-enrichment medium it would not be possible to fit all the required malic acid into the 6 capsules. It was discovered that a small portion of the magnesium chloride could be included in the pre-enrichment medium without damaging its recovery capability, thus providing more space in the capsules for malic acid. It was still necessary to reduce the buffering capacity of the pre-enrichment medium to limit the amount of malic acid to 0.8g per litre. Approximately 0.6g per litre of magnesium chloride was removed from the total test formulation without affecting selectivity.
  • Additional malachite green was included in the capsule formulation when compared to the traditional RV formulation. This was to overcome any absorption of dye by the food material that is now present throughout the test period. The new concentration has been shown not to be toxic to dye sensitive Salmonella strains.
  • the product is used in testing food samples for Salmonella as follows.
  • the Salmonella enrichment broth is prepared by suspending 4.275g of the pre-enrichment medium in 225 ml of distilled water and mixing to dissolve. The solution is distributed into containers and sterilised by autoclaving at 121 °C for 15 minutes. The food sample and Salmonella enrichment broth are allowed to come up to room temperature. 25g of the food sample is placed into a stomacher bag, eg a wired Sewards stomacher closure bag. 225 mis of Salmonella enrichment broth is added to the stomacher bag. The freeze dried OXYRASE is rehydrated with 2mls of sterile distilled water and mixed gently to avoid frothing.
  • the rehydrated OXYRASE is added to the stomacher bag in an amount to achieve a final concentration of 0.2 units per ml of pre-enrichment broth.
  • the stomacher bag is placed into a stomacher machine and mixed for 30 seconds. Timed-release capsules are added to the stomacher bag.
  • the food samples are placed into a 10-place stomacher rack, put on to a platform shaker in an air circulating incubator set at a temperature of 42 °C and the shaker set at 90 rpm (1.9 cm diameter circular orbit).
  • Figure 5 is a graph showing the temperature profile over 24 hours of a stomacher bag containing 225 ml pre- enrichment medium, 25 ml water (in place of a sample) and 6 capsules, placed in the centre of the bag rack of an otherwise empty shaker in an air circulating incubator at 42°C, and also shows the timing of bursting of the 6 capsules. After 24 hours incubation, the rack is taken out of the incubator. After this the pre-enrichment and enrichment steps are complete.
  • Further testing may be performed as desired, eg by subculturing on selective plates and performing confirmatory tests on any suspect Salmonella colonies, or by using a rapid technique of choice.
  • Each of ten of the most common serotypes of Salmonella associated with food were inoculated into each of the food types, at inoculum levels of approximately ⁇ 10 cfu/25g sample.
  • Test isolates were in most cases injured by heat treatment (51.5°C for 25 min) with the soft cheese samples being injured by low acid/high salt exposure (13Vz 7o NaCl, pH 4.5 at 4°C for 12 days). Uninoculated control samples were set up for each food. Each food/serotype combination was tested singly.
  • the samples were examined using both PHLS method and the method of the invention.
  • Example 2 Using the procedures described in Example 2, similar comparative tests were carried out on naturally contaminated food samples of various types.

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Abstract

L'invention porte sur un procédé d'enrichissement de la population d'un micro-organisme simple dans un échantillon, ce procédé consistant à incuber l'échantillon dans un milieu de pré-enrichissement, avec un ou plusieurs agents sélectifs, de façon à favoriser le développement du micro-organisme cible placé de façon à se libérer dans le milieu au bout d'une durée prédéterminée. Ce procédé combine des étapes de pré-enrichissement et d'enrichissement sélectif par libération échelonnée de l'agent ou des agents sélectifs. Ceci a l'avantage de réduire le nombre de manipulations et la somme de travail nécessaires pour la réalisation de ces étapes. Il s'est avéré que ces étapes peut être achevées de manière satisfaisante dans un délai de 24 heures sans que l'intervention d'un opérateur soit nécessaire. L'étape d'enrichissement peut être suivie de l'étape d'identification du micro-organisme cible, à l'aide de toute technique appropriée, soit traditionnelle, soit rapide. A l'aide des techniques d'identification rapide, le temps du test total peut être réduit à à peine 24 heures. Cette invention peut être appliquée notamment dans l'analyse d'échantillons de denrées alimentaires et de boissons au cours de l'enrichissement et de l'identification d'une large plage d'agents pathogènes d'origine alimentaire tels que Salmonella, Listeria, Campylobacter et E.coli O157, mais peut être également utilisée en association avec une large plage de micro-organismes cibles provenant d'une plus grande plage de types d'échantillons tels que des échantillons de l'environnement.
EP98932406A 1997-07-11 1998-07-10 Enrichissement selectif et detection de micro-organismes Withdrawn EP1009803A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP98932406A EP1009803A1 (fr) 1997-07-11 1998-07-10 Enrichissement selectif et detection de micro-organismes

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
GBGB9714594.0A GB9714594D0 (en) 1997-07-11 1997-07-11 Detection of microorganisms
GB9714594 1997-07-11
EP97307332 1997-09-19
EP97307332 1997-09-19
EP98932406A EP1009803A1 (fr) 1997-07-11 1998-07-10 Enrichissement selectif et detection de micro-organismes
PCT/GB1998/002016 WO1999002650A1 (fr) 1997-07-11 1998-07-10 Enrichissement selectif et detection de micro-organismes

Publications (1)

Publication Number Publication Date
EP1009803A1 true EP1009803A1 (fr) 2000-06-21

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EP98932406A Withdrawn EP1009803A1 (fr) 1997-07-11 1998-07-10 Enrichissement selectif et detection de micro-organismes
EP98932405A Withdrawn EP1002053A1 (fr) 1997-07-11 1998-07-10 Support de recuperation et de culture de micro-organismes

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EP98932405A Withdrawn EP1002053A1 (fr) 1997-07-11 1998-07-10 Support de recuperation et de culture de micro-organismes

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EP (2) EP1009803A1 (fr)
GB (1) GB9721396D0 (fr)
WO (2) WO1999002649A1 (fr)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0022556D0 (en) 2000-09-14 2000-11-01 Oxoid Ltd Improvements in or relating to selective agents for biological cultures
US9274101B2 (en) 2001-04-20 2016-03-01 Biolog, Inc. Methods and kits for obtaining a metabolic profile of living animal cells
FR2834998B1 (fr) 2002-01-18 2004-04-02 Millipore Sas Procede de controle de la presence de micro-organismes dans un milieu gazeux comprenant du peroxyde d'hydrogene
FR2845097B1 (fr) 2002-10-01 2006-06-16 Metis Biotechnologies Procede de detection et de comptage de microorganismes dans un echantillon
IT1393642B1 (it) 2009-04-08 2012-05-08 Gruppo Meccaniche Luciani Srl Calzatura con sistema di aerazione ottenuto con processo ad iniezione diretta su tomaia
EP2302029A1 (fr) 2009-09-29 2011-03-30 Fundacion Gaiker Dispositif portable d'enrichissement, aliquotage et test pour micro-organismes et toxines
FR2951738B1 (fr) 2009-10-26 2013-12-27 Pierre Philippe Claude Substrats matriciels carbones pour l'obtention de bacteries biofertilisantes
US20120282623A1 (en) * 2010-01-22 2012-11-08 Hitachi Chemical Research Center, Inc. Rapid pathogen detection techniques and apparatus
FR2993186B1 (fr) 2012-07-13 2014-07-25 Polyor Sarl Filtres macro/microporeux pour l'incubation et le diagnostique de l'activite microbiologique d'echantillons environnementaux
EP3344778A1 (fr) * 2015-09-03 2018-07-11 3M Innovative Properties Company Procédé d'enrichissement et de détection d'un micro-organisme cible

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1290271C (fr) * 1986-12-05 1991-10-08 Howard I. Adler Materiel et methode pour activer la croissance de bacteries anaerobiques
US5187070A (en) * 1990-10-09 1993-02-16 Kansas State University Research Foundation Assay for motile facultative anaerobic pathogens
US6010896A (en) * 1991-06-24 2000-01-04 Becton, Dickinson And Company Lyophilized ionizing radiation sterilized microorganisms as an additive for nutrient media for growing bacteria
GB9320733D0 (en) * 1993-10-08 1993-12-01 Scherer Corp R P Controlled release device construction
US5830746A (en) * 1994-05-04 1998-11-03 Oxyrase, Inc. Apparatus and method for growing anaerobic microorganisms
HU9401958D0 (en) * 1994-06-30 1994-10-28 Vamos Process and apparatus for rapid propagation and isolation of salmonella species
DE19512506C2 (de) * 1995-04-04 1997-06-12 Deutsches Krebsforsch Zellkultur-Medium
WO1996040861A1 (fr) * 1995-06-07 1996-12-19 Biolog, Inc. Milieux de cultures microbiologiques permettant d'isoler et d'identifier des pathogenes enteriques, tels que e. coli et salmonella

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9902650A1 *

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WO1999002649A1 (fr) 1999-01-21

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