METHOD AND DEVICE FOR THE QUALITATIVE AND QUANTITATIVE DETECTION OF BIOFILM-BUILDING BACTERIA CONTAINED IN AN AQUATIC SYSTEM

Abstract

A method and a device for performing are qualitative and quantitative assay of biofilm-forming bacteria of at least one bacterial species contained in an aquatic system by use of a biochemical reaction of the bacteria with at least one substance which initiates a bacterium-specific metabolic reaction, as well as a colorimetric reagent which can be influenced by the metabolic reaction involving measurement of the spectrometric properties thereof forming the basis of the assay.

Claims

1.-25. (canceled)

26. A method for the qualitative and quantitative assay of biofilm-forming bacteria of at least one bacterial genus contained in an aquatic system by using of a biochemical reaction of the bacteria with at least one substance which initiates a bacterium-specific metabolic reaction, and a colorimetric reagent which is influenced by the metabolic reaction, comprising measuring spectrometric properties and using the measured properties in performing the assay.

27. The method as claimed in claim 26, wherein: the bacteria contained in the aquatic system are assigned to one of the bacterial species of: Legionella pneumophila, Pseudomonas aeruginosa, Escherichia coli, Enterobacter aerogenes.

28. The method as claimed in claim 27, wherein: the biochemical reaction for the assay of the bacteria of the bacterial genus Legionella, of the bacterium Legionella pneumophila, is carried out with at least one of substances: -ketobutyric acid, L-serine, L-threonine, pyruvic acid methyl ester.

29. The method as claimed in claim 27, wherein: the biochemical reaction for the assay of the bacteria of the bacterial genus Pseudomonas aeruginosa, is carried out with at least one of substances: L-arginine, L-asparagine, itaconic acid, putrescine.

30. The method as claimed in claim 28, wherein: the biochemical reaction for the assay of the bacteria of the bacterial genus Pseudomonas aeruginosa, is carried out with at least one of substances: L-arginine, L-asparagine, itaconic acid, putrescine.

31. The method as claimed in claim 27, wherein: the biochemical reaction for the assay of the bacteria of the bacterial genus of the bacterium Enterobacter aerogenes, is carried out with at least one of substances: D-glutamic acid, D-cellobiose, Q-methyl-D-glucoside, D-mannitol.

32. The method as claimed in claim 27, wherein: the biochemical reaction for the assay of the bacteria of the bacterium Escherichia coli, is carried out with at least one of substances: D-mannitol, L-phenylalanine, -D-glucose, glucose 1-phosphate.

33. The method as claimed in claim 26, wherein: a redox indicator is used as the colorimetric reagent.

34. The method as claimed in claim 33, wherein: a tetrazolium salt in the form of (2,3,5-triphenyl-2H-tetrazolium chloride, TTC) or in the form of (2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphophenyl)-2H-tetrazolium, WST-1) with mPMS (1-methoxy-5-methylphenazinium methyl sulphate, as the electron mediator) is used as the redox indicator.

35. The method as claimed in claim 26, wherein: the spectrometric properties of the colorimetric reagent in the aquatic system are detected by use of optical spectrophotometry, in which an optical extinction which can be associated with an aquatic system containing bacteria of at least one bacterial genus is measured, in order to obtain at least one of an absolute extinction value and an extinction function which varies with time.

36. The method as claimed in claim 26, wherein: the biochemical reaction is carried out under microaerophilic incubation conditions at a temperature in the range between 25 C. and 45 C.

37. The method as claimed in claim 36 wherein the temperature is 37 C.

38. The method as claimed in claim 26, wherein: the spectrophotometric properties of the colorimetric reagent in the aquatic system are measured after a reaction period for the biochemical reaction of 20 hours to 50 hours.

39. The method as claimed in claim 38 wherein the measurement occurs after 24 hours.

40. The method as claimed in claim 26, wherein: a microtitre plate with a mutually isolated cavities is used, in which one of the at least one substances as well as the colorimetric reagent is pre-loaded into each cavity, and a sample of the aquatic system containing the biofilm-forming bacteria of at least one bacterial genus is introduced into each of the cavities of the microtitre plate.

41. The method as claimed in claim 26, wherein: at least one of prior to and while carrying out the biochemical reaction, the bacteria undergo at least one of a chemical and hydromechanical modification.

42. The method as claimed in claim 41, wherein: the chemical modification is carried out by adding at least one chemical agent to the bacteria selected from agents: polysorbate 80, rhamnolipids, surfactin.

43. The method as claimed in claim 41, wherein: the hydromechanical modification is carried out by applying ultrasound waves to the bacteria.

44. A microtitre plate for carrying out a qualitative and quantitative assay of biofilm-forming bacteria contained in an aquatic system, with cavities each containing a substance and a colorimetric reagent, wherein: a different substance is contained in each of at least two cavities, the substances being selected from the group formed by the following substances: -ketobutyric acid, L-serine, L-threonine, pyruvic acid methyl ester.

45. The microtitre plate as claimed in claim 44, wherein: a different substance is contained in each of at least two further cavities, the substances being selected from the group formed by the substances: L-arginine, L-asparagine, itaconic acid, putrescine.

46. The microtitre plate as claimed in claim 44, wherein: a different substance is contained in each of at least two further cavities, the substances being selected from the group formed by the following substances: D-glutamic acid, D-cellobiose, Q-methyl-D-glucoside, D-mannitol.

47. The microtitre plate as claimed in claim 44, wherein: different substances are contained in each of at least two further cavities, the substances being selected from the group formed by the following substances: and -D-glucose.

48. The microtitre plate as claimed in claim 44, wherein: the cavities contain, as the colorimetric reagent, a redox indicator in the form of a tetrazolium salt (2,3,5-triphenyl-2H-tetrazolium chloride, TTC) or (2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphophenyl)-2H-tetrazolium, WST-1) with mPMS (1-methoxy-5-methylphenazinium methyl sulphate, as the electron mediator).

49. A use of the microtitre plate as claimed in claim 44, for performing a qualitative and a quantitative assay of Legionella pneumophila contained in an aquatic system.

50. A use of the microtitre plate as claimed in claim 48, for the qualitative and quantitative assay of biofilm bacteria, which contain at least one bacterial species of bacterial species in an aquatic system: Legionella pneumophila, Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli.

51. A use as claimed in claim 49, of investigating water as the aquatic system be removed from water distribution systems for people and animals, industrial units and cooling towers.

52. A use as claimed in claim 49 of investigating in medical, chemical or biochemical fields liquids as the aquatic system.

53. Use as claimed in claim 52, wherein: An investigation is performed in the medical field, involving urine, cerebrospinal fluid, bile, sputum, gastric juices, breast milk, vaginal secretions, lachrymal fluid, nasal discharges, and ejaculate.

Description

BRIEF DESCRIPTION OF THE INVENTION

[0043] The invention will now be described by way of example in a manner which does not limit the general inventive concept, with the aid of an exemplary embodiment and with reference to the accompanying drawings, in which:

[0044] FIG. 1 shows a diagrammatic representation of the distribution of different substances in cavities of a microtitre plate.

DETAILED DESCRIPTION OF THE INVENTION

[0045] FIG. 1 shows a tabular arrangement having four columns (1, 2, 3, 4) and eight rows (A-H), in which 32 fields can be distinguished from each other by an individual column and row address. The tabular arrangement constitutes a highly diagrammatic illustration of a microtitre plate the cavities of which are represented by the 32 fields.

[0046] Selected fields or cavities of a microtitre plate represented by the tabular arrangement each contain the substances that can be seen in FIG. 1, which can each initiate a bacterium-specific metabolic reaction. In each case, underneath the substance given in the individual fields/cavities, the name of the bacterium that reduces the substance in the aquatic system during the course of a metabolic reaction is shown in bold type. A representative example in this regard that may be cited is the cavity in row A column 2 which contains the substance -methyl-D-glucoside in order to assay the bacterium Enterobacter aerogenes.

[0047] In addition to the twelve fields/cavities filled with different substances, in one cavity, preferably in the cavity A/1, water has been pre-loaded as a neutral buffer medium, with the aid of which in the context of a photometric measurement, a reference comparison with what is known as the blank sample can be undertaken.

[0048] Together with the substances pre-loaded in the cavities, each cavity contains a colorimetric reagent in the form of a redox indicator, preferably a tetrazolium salt, for example in the form of (2,3,5-triphenyl-2H-tetrazolium chloride, TTC) or (2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphophenyl)-2H-tetrazolium, WST-1) with mPMS (1-methoxy-5-methylphenazinium methyl sulphate, as the electron mediator).

[0049] The geometric arrangement illustrated in FIG. 1 of the individual substances distributed over the various cavities should not be understood to be limiting; clearly, almost any alternative spatial distributions of the substances in the cavities of a microtitre plate are possible. In addition, the fields/cavities which are not filled with substances, for example A/3, B/1, B/2, B/3, C/1 etc., could be filled with other substances or the substances which have already been disposed in the microtitre plate.