EP1068527A2 - Procede rapide de detection de micro-organismes et d'evaluation de l'activite antimicrobienne - Google Patents

Procede rapide de detection de micro-organismes et d'evaluation de l'activite antimicrobienne

Info

Publication number
EP1068527A2
EP1068527A2 EP99914648A EP99914648A EP1068527A2 EP 1068527 A2 EP1068527 A2 EP 1068527A2 EP 99914648 A EP99914648 A EP 99914648A EP 99914648 A EP99914648 A EP 99914648A EP 1068527 A2 EP1068527 A2 EP 1068527A2
Authority
EP
European Patent Office
Prior art keywords
micro
organisms
sample
organism
zeta potential
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Withdrawn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
EP99914648A
Other languages
German (de)
English (en)
Inventor
Phillip Brown
Stuart Zetatronics Ltd Uni of Hertford HARBRON
Gordon Chalmers Mellis Zetatronics Ltd. YOUNG
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.)
Zetatronics Ltd
Original Assignee
Zetatronics 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 GBGB9806759.8A external-priority patent/GB9806759D0/en
Priority claimed from GBGB9825222.4A external-priority patent/GB9825222D0/en
Application filed by Zetatronics Ltd filed Critical Zetatronics Ltd
Publication of EP1068527A2 publication Critical patent/EP1068527A2/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Withdrawn legal-status Critical Current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
    • C12Q1/18—Testing for antimicrobial activity of a material
    • 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
    • C12Q1/04—Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator 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
    • C12Q2304/00—Chemical means of detecting microorganisms
    • C12Q2304/80—Electrochemical detection via electrodes in contact with culture medium

Definitions

  • the present invention relates to methods and apparatus for the detection of the presence of specific micro-organisms in a fluid It is particularly applicable, but in no way limited, to identifying microbial pathogens in liquid solution
  • the invention also relates to methods for antibiotic sensitivity testing, and in particular methods for assessing the effectiveness of antimicrobial agents, for screening compounds for antimicrobial activity, and for determining an appropriate means of treatment for an unknown microbial infection
  • micro-organism has a broad meaning It encompasses bacteria, viruses and fungi
  • micro-organisms It is also known to detect micro-organisms by the use of specific probes that are designed to attach themselves to the micro-organism by covalent bonding and thus to attach a marker to them so that they may be detected by some physical property Unlike the present invention such techniques are slow and can only search for one micro-organism at a time
  • antibiotic sensitivity of bacteria can be assessed in a variety of ways 1 Agar Diffusion tests, in which the antibiotic is allowed to diffuse from a point source, commonly in the form of a filter paper disc, into an agar medium which has been seeded with a test organism
  • Agar incorporation tests which are essentially similar to broth dilution tests except that the antibiotic dilutions are incorporated in an agar medium in a series of Pet ⁇ dishes
  • These are spot-inoculated with a number of test organisms, usually be means of a semi-automatic inoculation device
  • Lead molecules are typically only weakly active, and may be toxic or otherwise unsuitable for use as drugs
  • lead expansion in which hundreds or thousands of variants of the most promising leads are made These are tested, and some are typically found to be more active and/or less toxic than the original leads This process can be iterative
  • combinatorial library approach is also suitable for this lead expansion phase
  • a method of identifying one or more micro-organisms in a fluid comprising the steps of - (i) taking a sample of the fluid containing a representative sample of any m ⁇ cro-organ ⁇ sm(s) present, (n) optionally cultunng the sample if necessary to increase the number of micro-organisms for a pre-determined range, (MI) measuring the zeta potentials of any micro-organisms present, (iv) optionally normalising the measurements taken in step (in) such that they relate to standard conditions, (v) comparing said measured zeta potentials with a table of the zeta potentials of known micro-organisms to determine which, if any, of the known micro-organisms are present in the fluid
  • a method of determining the presence of a specific micro-organism in a liquid solution which comprises applying an electric field across the solution, optically measuring the speed of movement of any micro-organism suspended in
  • the measured speed of movement or electrophoretic mobility is an indication of the electro-kinetic potential, also termed zeta potential, of the micro-organism and is dependent upon several physical properties of the micro-organism including size, shape, overall charge and surface charge distribution As well as permitting a solution to be analysed for the presence of a specific micro-organism, by comparing the zeta potentials measured during analysis of a solution with a table of the zeta potentials of known micro-organisms, the invention can enable rapid analysis of a solution to determine what mixture of microorganisms are present
  • an apparatus for determining the presence of a specific micro-organism in a liquid solution which comprises means for applying an electric field across a measurement cell containing the solution, a laser light source for illuminating the cell, detecting means for sensing light after impinging on a micro-organism suspended in the solution, means for analysing the scattered light to provide a measurement of the speed of movement of the micro-
  • the apparatus of the invention as well as distinguishing between micro- organisms on the basis of their electo-kinetic potential, achieves improved sensitivity by allowing the scattering angle at which light is detected to be optimised for the micro-organism of interest as it has been found in practice that light from different micro-organisms is scattered in different directions
  • the laser light source comprises a laser, a beam splitter for dividing the light emitted from the light source into two coherent beams, means for directing the light beams along different directions and means for modulating the length of one of the light paths to create a variable interference pattern between the two beams at the cell
  • modulating the length of one of the light paths will be that the interference pattern will oscillate along the cell and light scattered by a stationary particle or micro-organism will pulsate at the frequency of the modulation If the particle is moving however, it will move with the interference in one direction and in opposition to it in the opposite direction
  • the frequency of modulation of the scattered light will differ from the frequency of modulation of the length of one of the light paths by an amount indicative of the rate of movement of the particle in the cell
  • the detected frequencies of light scattered by moving particles when the applied electric field is reversed should be symmetrical about the modulation frequency of the light path If, however, the electrodes of the cell are polarised then reversal of the potential applied
  • the speed with which a given micro-organism will move through a solution when an electric field is applied will depend on certain factors other than the zeta potential, such as the pH and temperature of the solution It is preferred to maintain these factors constant during measurement but it is alternatively possible to measure these parameters and compensate the measurement obtained
  • a method of identifying the cause of an infection in a human or animal body comprising the steps of -
  • This method can be used to direct a physician to an appropriate course of treatment For example, not only can the method flag up the infecting species, but it can also list a range of possible drug treatments known to be effective against the micro-organisms which have been identified The physician would then select the appropriate treatment based on this information, the symptoms exhibited by the patient and the physicians skill and experience
  • the method comprises
  • the step correlating said change in zeta potential to either the antimicrobial sensitivity of a micro-organism or to the antimicrobial activity of a an antimicrobial agent may be automated
  • Advantages of the present invention include avoidance of the development of drug-resistant strains, economic dispensing of medicines, and an increase in the quality of patient care
  • Another object of the present invention is to provide a method for assessing emerging drugs for antimicrobial activity
  • Advantages of the present invention include determination of MIC values, investigation of the effects of the candidate drugs on microbial physiology, and determination of the mechanism of action of the candidate drug
  • a further object of the present invention is to provide a method for screening for agents having antimicrobial activity.
  • Advantages of the present invention include the ability quickly to perform large-scale, automated screening; to identify drugs which affect cell vitality but not cell viability.
  • a yet further object of the present invention is to provide an automated method for screening agents for antimicrobial activity.
  • Figure 1 illustrates a stylised diagram of a yeast cell
  • Figure 2 illustrates graphically the diffuse double layer around a sphere of moderate potential
  • Figure 3 illustrates schematically a typical double beam apparatus for measuring zeta potentials
  • Figure 4 shows the Zeta potential profile of a control sample of S pneumoniae
  • Figure 5 shows the zeta potential profile of a sample of S pneumoniae treated with penicillin.
  • Microelectrophoresis is a division of the science of electrophoresis and deals specifically with particles in the region of less than 20 ⁇ m and with a minimum dimension in the order of 0 01 ⁇ m Below this limit, objects are considered to be of molecular dimensions There is considerable blurring of this lower border especially when dealing with macromolecules Electrophoresis has long been the method of choice for identifying many charged molecular species, such as proteins, nucleic acid and ammo acids
  • DNA finger printing which allows the separation and matching of two samples of DNA Micro-organisms of all types, from bacteria to viruses fall into the size range applicable to microelectrophoresis Viruses are particularly interesting because they are composed mostly of protein and nucleic acid and tend to have a relatively stable, uniform structure As such, they provide a direct link with conventional electrophoresis techniques When any surface is placed in contact with an aqueous solution the surface acquires a surface charge which is usually negative The origins of this are either absorption of ions from solution
  • Figure 1 describes how the microorganisms can be regarded from this view point
  • the shaded areas represent areas of hydrophobic surface at which charge builds up at the surface through contact absorption
  • Also shown at this surface are the charges native to the surface of the micro-organism and specifically absorbed at the surface.
  • the charge produces an electrical double layer and the electrical potential varies as described by Figure 2.
  • Fig. 2 shows the distribution of charge across a double layer at the surface of a hypothetical micro-organism.
  • the charge at the shear surface is the zeta potential; beyond this the charge decays away rapidly in the bulk solution.
  • the surface charge of an idealised micro-organism arises from two sources.
  • First groups on the surface of the micro-organism such as carboxylate groups, may be ionised.
  • ions may be adsorbed from solution onto the surface of the micro-organism, particularly at hydrophobic regions on the surface where anionic groups may be preferentially adsorbed.
  • Apparatus for measuring zeta potentials are known per se.
  • One such example is the ZETASIZER 2000 (TM) made by Malvern Instruments.
  • This instrument is used to measure particle size. It utilises a dual laser beam and a photodetector is arranged to measure deflected light at a fixed scattering angle.
  • FIG. 3 A typical double beam instrument is shown in Figure 3 which illustrates a neon-helium laser 10 producing a red laser beam
  • the beam is incident upon a beam splitter 12 that allows half the incident light energy to pass through it towards a mirror and modulator 1 and reflects the other half towards a mirror 18.
  • the mirror and modulator 14 is a mirror vibrated by a piezoelectric vibrator that reflects the incident beam towards a further stationary mirror 16
  • the two halves of the split laser beam are focused by a lens 20 an a cell 22 that contains a liquid to be analysed
  • An electric field that is reversed periodically is applied across the cell by means of electrodes 22 and 24 and this causes micro-organisms in the liquid to move with a characteristic velocity towards the electrode that instantaneously has the opposite polarity to the net charge on the micro-organism
  • the microorganism is illuminated by the laser light it scatters the incident light in a predetermined direction and this light is sensed by means of a detector 26
  • the two halves of the split laser beam travel different distances before reaching the cell 20
  • the path length is modulated periodically
  • the two halves of the split laser interfere with one another and the interference pattern will move across the cell
  • a stationary particle suspended in the cell will scatter light at a frequency related to the frequency of modulation of the mirror 14
  • a particle is moving towards one end of the ceil 20 or the other, then while it is moving with the interference pattern, light scattered from it will have a lower frequency and conversely when the particle is moving in the opposite direction to the interference pattern light scattered from it will have a higher frequency
  • By analysing the frequency of the scattered light sensed by the detector 26 it is possible to determine the speed and direction of movement of the particle
  • the speed of movement is related to the distribution of charge about the surface of the particle and is indicative of the so-called zeta potential Depending on the shape of the particle, it will align itself differently in the applied electric field and for any specific micro-organism there will be an angle at which the intensity of the scattered light is a maximum
  • the apparatus may therefore be used to determine the presence of a specific micro-organism in the solution being analysed by setting the detector 26 to the scattering angle associated with the micro-organism and monitoring the output of the detector for the frequencies corresponding to the previously determined speed of movement of the micro-organism in the applied field It is preferred to take steps to prevent polarisation of the electrodes 22, 24 as such polarisation may affect the electric field as sensed by particles suspended in the liquid in the cell 20.
  • Polarisation may be prevented by pe ⁇ odically switching the polarity of the electric field. Such switching will in itself prevent polarisation but additionally it will allow polarisation to be detected as the detected frequencies will not be symmetrical about the frequency of movement of the bands of the interference pattern.
  • the detector type used in this application can take a number of forms. However, we have found that commercially available solid state photodiodes such as Radio Spares Model AEPX 65 (Stock No 846/749) work well.
  • the nature of the data captured takes the form of a senes of exponential decays These represent the length of time taken for the scattered light to decay to zero, this is effectively the particle velocity
  • the exponential decays are converted to mean normal distributions.
  • This method of handling the data measured is contained in a software programme as a means for analysing the scattered light.
  • the software can contain a library or table of recorded measurements for known micro-organisms.
  • a comparator programme can be run such that the operator receives as a print-out or screen message a list of those micro-organisms considered to be present
  • look-up table is used as a generic term to encompass any compilation of zeta potential measurements obtained for known microorganisms.
  • This look-up table can take a variety of forms. It may, for example, be a physical table whereby comparisons are made manually Alternatively, and preferably, the "table" can be a computer database of results.
  • a comparator programme then compares a measured value, or series of measured values, against known results Limits may be included within the programme such that a "best fit” only answer is provided or a range of "possibilities" can be given
  • the comparator programme may also advantageously contain the necessary calculations to normalise the measured zeta potential values such that they relate to standard conditions
  • An apparatus of the general type described above has been used to measure the electrophoretic mobility and zeta potentials of known micro-organisms. The machine was calibrated using a standard NaCI solution having a conductivity of 0.15mS and a pH of approximately 7 0 Test samples were normalised to this conductivity by use of the B ⁇ ggs equation, which in this case takes the form
  • Table II indicates that the only two members of the table that are not separable are the two members of the liste ⁇ a group of organisms.
  • the elimination of the zeta potential corresponding to the micro-organism of interest is a confirmatory test if the agent is specific for the micro-organism of interest
  • the agent may be an antibiotic, antibacterial or other selective poison
  • the same end may also be accomplished by contacting the sample with an agent that specifically causes the agglomeration of the microorganism, such as an antibody or other immunological reagent, whereby the micro-organism is precipitated out of solution
  • Dosage means to infect a solution of acid or alkali is known per se to the person skilled in the art
  • Typical bases which can be used are sodium or potassium hydroxide or an amine base such as tnethylamine Acids include hydrochloric or sulphuric acid or organic acids such as acetic or citric acid.
  • the apparatus may advantageously include a pH meter such that the pH of the solution in the cell is measured and recorded automatically.
  • the uniformity of virus structures would give every indication that viruses can be distinguished one from another in a similar way
  • this method represents an important new method of diagnosis which can be performed in vitro on a sample removed from the human body
  • the method does not have to be performed by a medical practitioner but can be readily carried out by a technician.
  • the technician need not have any medical knowledge in order to carry out this method effectively and requires only the most basic of training
  • the method provides the medic with a clear indication of which pathogenic bacteria, or combination of bacteria, are present in the patient's sample From that information and the symptoms experienced by the patient, the medic can then formulate the most appropriate treatment It provides, in effect, an intermediate result upon which to decide on a suitable course of treatment
  • the pH value of the solution and its temperature should always be the same during measurement as the pH may affect the measured zeta potential but it is alternatively possible to compensate the obtained measurement for changes in pH and temperature
  • an important advantage of the present invention is that while the chemical composition of the micro-organism is the same whether it is alive or dead, the zeta potential changes when the micro-organism dies because the charge distributed around the micro-organism is affected by the chemical processes taking place while the organism is alive, especially near its outer periphery If, therefore, steps have been taken to eliminate a micro-organism that is the cause of an infection, the present invention can be used to determine if such steps have been effective
  • the invention has been described in relation to identifying organisms in a solution
  • the term "solution” has a very broad meaning It refers to any liquid, organic or inorganic, which may contain a micro-organism It includes, by way of example only, notionally pure water, brewing worts, body fluids such as urine and diluted samples of these, plant extracts or swabbings and solutions obtained by bubbling a gas through a liquid in order to entrain any micro-organisms present in the gas In this way contaminations in gase
  • the bacterial count in the urine from patients having urinary infections is in the order of 10 6 to 10 7 cells per ml These levels are easily and rapidly detected using the method of the present invention, and it is anticipated that an indication of the infecting pathogen will be provided within 5 minutes
  • Food and water samples tend to contain rather fewer bacteria per ml, and for these the sample will need to be cultured
  • the sample may be mixed with, for example, McConkey's broth
  • the cultured sample may be analysed for the presence or absence of micro-organisms using the method of the present invention No filtration is necessary and the broth ingredients do not interfere with the analysis
  • Food samples are prepared, for example, by swabbing the surface of the food or macerating the food
  • Salmonella could be detected in a chicken neck flap swab within 7h, and indications are that 200 cells per ml of Salmonella (a level which is considered to be infective) could be detected within 2 5h culture time
  • this method can be applied to provide a method of antibiotic sensitivity testing
  • the method comprises measuring the zeta potential of a microbial sample, which may be a known micro-organism or a clinical or veterinary sample, the sample is then exposed to an antimicrobial agent, subsequent measurement of the zeta potential indicates both the potency of the antibacterial material, and the sensitivity of the microbial sample to that material
  • the approach may be applied to assessing the antimicrobial activity of a mate ⁇ al
  • the material may be a compound or mixture of compounds isolated from a natural source, it may be a compound that is a derivative of a known family of antimicrobial agents, or it may be one or more compounds from a library of compounds produced by combinatorial chemistry techniques Typically these libraries contain between 5 and 50 variants of a candidate therapeutic agent
  • the approach may be applied to determining the antimicrobial susceptibility of a clinical or veterinary sample obtained from a patient or animal suspected of suffering from a microbial infection to determine the most effective treatment of the infection
  • the present invention is directed toward a method for assessing antimicrobial sensitivity
  • the invention provides a method for rapidly assessing the susceptibility of a patient or veterinary sample to a spectrum of antimicrobial agents in order to determine the most appropriate treatment to be initiated This process could be automated, so that a patient would have a sample taken during the morning by a nurse or technician, the sample would be analysed according to the present invention, and a prescription for the most appropriate antibiotic would be available later that day
  • a machine is envisaged in which a sample from a patient is divided into x samples and each sample is incubated to provide about 10 5 cells per sample Each sample is then treated with a different antibiotic and incubation continued After set periods of time the zeta potential of each sample is measured The antibiotic associated with the sample whose zeta potential tends to zero quickest is the treatment of choice.
  • a printer associated with the machine can then print out a prescription for checking and signature by the medical practitioner.
  • This method is not a method of diagnosis as such. It simply provides the medical practitioner with information on which agent(s) kills the micro-organism(s) most satisfactorily in vitro. It can be carried out by a technician with no medical knowledge and only basic training.
  • the invention may be applied to assessing emerging drugs for antimicrobial activity.
  • the invention can be applied to screening for agents having antimicrobial activity.

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Zoology (AREA)
  • Wood Science & Technology (AREA)
  • Proteomics, Peptides & Aminoacids (AREA)
  • Molecular Biology (AREA)
  • Toxicology (AREA)
  • Immunology (AREA)
  • Microbiology (AREA)
  • Biophysics (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Biotechnology (AREA)
  • Biochemistry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Genetics & Genomics (AREA)
  • Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
  • Apparatus Associated With Microorganisms And Enzymes (AREA)
  • Investigating Or Analysing Biological Materials (AREA)

Abstract

La présente invention concerne un procédé permettant d'identifier un ou plusieurs micro-organismes dans un fluide. Ce procédé met en oeuvre plusieurs opérations: (i) Prélèvement d'un échantillon de fluide contenant un échantillon de tous les micro-organismes présents. (ii) mise en culture éventuellement de l'échantillon s'il y a besoin d'augmenter le nombre de micro-organismes en vue d'une plage définie. (iii) Mesure des potentiels z de tous les micro-organismes présents. (iv) Eventuellement rationalisation des mesures tirée de l'opération (iii) de façon à les ramener à des conditions standards. (v) Comparaison des potentiels z mesurés avec un tableau de potentiels z de micro-organismes connus afin de déterminer les éventuels micro-organismes connus présents dans le fluide.
EP99914648A 1998-03-31 1999-03-30 Procede rapide de detection de micro-organismes et d'evaluation de l'activite antimicrobienne Withdrawn EP1068527A2 (fr)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
GB9806759 1998-03-31
GBGB9806759.8A GB9806759D0 (en) 1998-03-31 1998-03-31 Detection of micro-organisms
GBGB9820703.8A GB9820703D0 (en) 1998-03-31 1998-09-24 Improved method of detecting micro-organisms
GB9820703 1998-09-24
GBGB9825222.4A GB9825222D0 (en) 1998-11-19 1998-11-19 A rapid method for evaluating antimicrobial activity
GB9825222 1998-11-19
PCT/GB1999/001001 WO1999050659A2 (fr) 1998-03-31 1999-03-30 Procede rapide de detection de micro-organismes et d'evaluation de l'activite antimicrobienne

Publications (1)

Publication Number Publication Date
EP1068527A2 true EP1068527A2 (fr) 2001-01-17

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EP99914648A Withdrawn EP1068527A2 (fr) 1998-03-31 1999-03-30 Procede rapide de detection de micro-organismes et d'evaluation de l'activite antimicrobienne

Country Status (5)

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EP (1) EP1068527A2 (fr)
JP (1) JP2002510049A (fr)
AU (1) AU3338299A (fr)
CA (1) CA2326320A1 (fr)
WO (1) WO1999050659A2 (fr)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2363842A (en) * 2000-02-17 2002-01-09 Zetatronics Ltd Micro-organism identification
GB0010628D0 (en) * 2000-05-04 2000-06-21 Zetatronics Ltd Process and apparatus for monitoring and controlling fermentation processes
JP5618284B2 (ja) * 2007-12-27 2014-11-05 昇一 城武 グラム陽性細菌用抗菌剤
JP2013538567A (ja) * 2010-08-12 2013-10-17 ザ リージェンツ オブ ザ ユニバーシティ オブ カリフォルニア 抗菌化合物を同定するおよび抗生物質感受性を決定する方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3722504A (en) * 1969-12-23 1973-03-27 P Sawyer Method of screening substances for use in the treatment of circulatory system diseases
WO1979000834A1 (fr) * 1978-03-24 1979-10-18 High Stoy Tech Systeme d'analyse d'echantillons chimiques et biologiques
CA2097295A1 (fr) * 1991-09-30 1993-03-31 Palitha Jayaweera Selection et utilisation de materiaux de revetement pour la prevention de l'encrassage des surfaces et de la corrosion par mesurage du potentiel electrocinetique

Non-Patent Citations (1)

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Title
See references of WO9950659A3 *

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Publication number Publication date
JP2002510049A (ja) 2002-04-02
CA2326320A1 (fr) 1999-10-07
WO1999050659A3 (fr) 2000-01-20
AU3338299A (en) 1999-10-18
WO1999050659A2 (fr) 1999-10-07

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