System for rapid analysis of microbiological materials in liquid samples

• US 20050266516A1
• Filed: 05/05/2005
• Published: 12/01/2005
• Est. Priority Date: 05/11/2004
• Status: Active Grant

• Current Assignee: Les Entreprises Biospec Global Solutions Inc.
• Original Assignee: Les Entreprises Biospec Global Solutions Inc.
• Inventors: Emburgh, Ron, Kanipayor, Ravi
• Granted Patent: US 8,373,861 B2
• Time in Patent Office: Days
• US Class Current: 435/34
• CPC Class Codes: C12Q 1/04 Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator therefor C12Q1/6897 takes precedence

Abstract

A system for the rapid analysis of microbiological parameters includes a specimen container for containing a liquid sample, a housing having an enclosable chamber shaped for receiving the specimen container, an incubating system mounted within the housing for incubating microbiological materials within the liquid sample, and a spectrophotometer system mounted within the housing for measuring light absorbed, emitted or scattered by the liquid samples as the microbiological materials are incubated by the incubating system over time. The specimen container is filled with a liquid sample to be tested and mixed with a reagent that provides a detectable parameter, and placed inside the apparatus. The incubation system heats and maintains the temperature of the liquid sample within a preset range while the spectrophotometer system propagates light within the specimen container, and monitors and records changes in the light as the light propagates through the container. A continuous non-intrusive monitoring and recording of the test parameter is achieved as the incubation progresses. Any significant deviation of the signal output is an indication of presence of the detectable parameter, while the time taken to reach the significant deviation provides quantification of the microbiological parameter under investigation.

Claims

1. A system for rapid analysis of microbiological materials in a liquid sample, comprising of:

(a) a specimen container for containing a liquid sample, the specimen container being made from a material that allows for propagation of light;

(b) a housing having an enclosable chamber shaped for holding the specimen container;

(c) an incubating system mounted within the housing for incubating any microbiological materials within the liquid sample; and

(d) a spectrophotometer system mounted within the housing for propagating light within the specimen container and measuring the light absorbed, emitted or scattered by the liquid sample as the microbiological materials are incubated by the incubating system over time.

2. The system defined in claim 1, wherein the spectrophotometer system comprises at least one spectrophotometer, the spectrophotometer comprising a light emitting source positioned to propagate light within the specimen container, a detector positioned for detecting changes in amount of the light as the light propagates through the microbiological materials and for producing a detector signal indicative of the changes, and a spectrophotometer controller for controlling the light emitting source and the detector.

3. The system defined in claim 2, wherein the spectrophotometer controller comprises a microprocessor for processing the detector signal and for generating a record of the changes in the light as a function of time.

4. The system defined in claim 2, wherein the light emitting source propagates light having a known intensity along a first optical path within the specimen container, and the detector detects the changes in the intensity of the light within a field of view related to the first optical path.

5. The system defined in claim 3, wherein the field of view is positioned at a 180°

angle to the first optical path.

6. The system defined in claim 3, wherein the field of view is positioned at a 90°

angle to the first optical path.

7. The apparatus defined in claim 2, wherein the light emitting source comprises a light emitting diode, and the detector comprises a phototransistor.

8. The system defined in claim 1, wherein the spectrophotometer system comprises a first spectrophotometer and a second spectrophotometer, wherein the first spectrophotometer comprises a first light emitting source for propagating a first beam of light within the specimen container and a first detector for detecting changes in the first light beam, and the second spectrophotometer comprises a second light emitting source for propagating a second beam of light within the specimen container, and a second detector for detecting changes in the second beam of light.

9. The system defined in claim 8, wherein the spectrophotometer system comprises a third spectrophotometer, the third spectrophotometer comprising a third light emitting source for propagating a third beam of light within the specimen container and a third detector for detecting changes in the third beam of light.

10. The system defined in claim 2, wherein the housing comprises an upwardly extending, generally cylindrical container holder having an open top, and a removable cap for enclosing the housing, the removable cap being shaped to surround the container holder.

11. The system defined in claim 10, wherein the light emitting source and the detector are mounted in the container holder at a location proximate to the specimen container when the specimen container is placed in the housing.

12. The system defined in claim 10, wherein the container holder comprises an inwardly extending indent, and the specimen container comprises a side recess shaped to register with the indent when the specimen container is placed in the container holder.

13. The system defined in claim 10, wherein the container holder comprises a pair of diametrically opposed indents, and the specimen container comprises a pair of diametrically opposed recesses shaped to register with the indents.

14. The system defined in claim 1, wherein the incubating system comprises a heating element, a temperature sensor, and a heating controller responsive to the temperature sensor for controlling the heating element.

15. The system defined in claim 14, wherein the temperature sensor extends upwardly into the chamber, and the specimen container has a bottom cavity shaped to accommodate the temperature sensor.

16. The system defined in claim 14, wherein the heating element extends upwardly into the chamber, and the specimen container has a bottom cavity shaped to accommodate the heating element.

17. Apparatus for incubating and detecting microbiological materials in a liquid sample, comprising:

(a) a housing having an enclosable chamber shaped for holding a clear plastic specimen container for containing a liquid sample;

(b) incubating apparatus mounted within the housing for incubating any microbiological materials within the liquid sample, and

(c) spectrophotometer apparatus mounted within the housing for propagating light within the specimen container and measuring light absorbed, emitted or scattered by the liquid sample as the microbiological materials are incubated by the incubation apparatus over time.

18. The apparatus defined in claim 17, wherein the spectrophotometer apparatus comprises a light emitting source for propagating a beam of light of a known intensity along a first optical path within the specimen container, and a detector for detecting changes in the intensity of the light along a second optical path related to the first optical path.

19. The apparatus defined in claim 18, wherein the housing comprises a base, a container holder mounted on the base for holding the specimen container, the container holder having an open top, and a removable cap shaped to enclose the top of the sample holder.

20. The apparatus defined in claim 19, wherein the incubating apparatus comprises a heating element, a temperature sensor, and a heating and temperature controller coupled to the temperature sensor for controlling the heating element.

21. A method for the rapid analysis of microbiological materials in a liquid sample, comprising the steps of:

(a) mixing a liquid sample having an unknown initial population of a microbiological material with a reagent in a specimen container, the reagent providing a detectable parameter indicative of the microbiological material, thereby creating a sample/reagent mixture;

(b) placing the specimen container in an enclosable housing and enclosing the housing;

(c) incubating the sample/reagent mixture in the enclosed housing at a temperature within a pre-selected temperature range over a period of time; and

(d) measuring changes in the detectable parameter as the sample/reagent mixture is being incubated during the period of time.

22. The method of claim 21, further comprising the steps of recording the changes in the detectable parameter as a function of time.

23. The method defined in claim 21, wherein the step of measuring changes in the detectable parameter comprises propagating light within the sample/reagent mixture in the specimen container and detecting changes in the light.

24. The method defined in claim 22, further comprising the steps of:

(a) recording a time of significant deviation at which there occurs an exponential change in the detectable parameter; and

(b) determining the initial population by correlating the time of significant deviation with known times of exponential growth for known initial concentrations of the microbiological material.

25. The method defined in claim 21, wherein the pre-selected temperature range is ±

1°

C.

26. The method defined in claim 21, wherein the detectable parameter is selected from a group comprising colour, fluorescence and turbidity.

27. The method defined in claim 21, wherein the detectable parameter comprises bioluminescence or chemiluminescence resulting from a biological or chemical component in the reagent.

28. A method for the rapid quantitative analysis of microbiological materials in a liquid sample, comprising the steps of:

(a) placing a liquid sample having an unknown initial population of a microbiological material in a specimen container made of a material that allows for the propagation of light;

(b) creating a sample/reagent mixture by mixing the liquid sample with a reagent that provides a detectable parameter indicative of the microbiological material upon exposure to light;

(c) incubating the sample/reagent mixture in an enclosed housing at a temperature within a pre-selected temperature range over a period of time;

(d) measuring changes in the detectable parameter as the sample/reagent mixture is being incubated over the period of time by propagating light within the sample/reagent mixture in the specimen container and detecting changes in the intensity of the light;

(e) recording the changes in the intensity of the light as a function of time;

(f) recording a time of significant deviation at which there occurs an exponential change in the intensity of the light; and

(g) determining the initial population by correlating the time of significant deviation with known times of exponential growth for known initial concentrations of microbiological materials.