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• • 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
  • C12Q1/68—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
  • C12Q1/6876—Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes
  • C12Q1/6888—Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes for detection or identification of organisms
  • C12Q1/689—Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes for detection or identification of organisms for bacteria

Definitions

• the invention relates to a method for identifying Escherichia coli (E. coli) strain DSM 6601.
• Escherichia coli is a gram-negative bacterium that is found in the human and animal intestinal flora, but also extraintestinal. E. coli is today the most important host organism among the microbial cloning systems of genetic engineering for the expression of heterologous proteins as well as for cloning and DNA amplification.
• E. coli occurs in numerous variants, which differ in terms of capsule antigens (K antigens), surface antigens (O antigens) and flagella antigens (H antigens) and can therefore be divided into numerous serological types.
• K antigens capsule antigens
• O antigens surface antigens
• H antigens flagella antigens
• the classification according to the serotypes says nothing about the different virulence of the pathogens.
• Representatives of one and the same serotype can have different pathogenicity potential in both the human and animal body, which in extreme cases can range from avirulent to highly pathogenic. It is known that the E. coli strain DSM 6601 is rated as non-human or animal pathogenic.
• a method for identifying E. coli strain DSM 6601 is now proposed, which is characterized in that certain primer pairs from the plasmids or the fimA and foc ⁇ sequences of the bacterial DNA are used in a PCR reaction.
• the PCR polymerase chain reaction
• the detection method according to the invention is based on that of RK Saiki et al. methods described in Science 239: 487-491 (1988).
• primers that is, oligonucleotides, which generally have a length of about 15 to 30 nucleotides and whose sequences are complementary to the start and end sequences of the sister strands of the DNA to be amplified, are required.
• the double-stranded DNA of the sequence to be amplified is denatured by heating so that it separates into single strands.
• the complementary strand is formed later in the course of the single-stranded region of the nucleic acid referred to as a template or template.
• the mixture with the primers is cooled, the primer nucleotides hybridizing at the ends of the single-stranded DNA and thereby preventing the original single-stranded DNA from reuniting. This is followed by increasing the Temperature a mixture of the four DNA-typical nucleotide 5'-triphosphates and a temperature-stable DNA polymerase.
• the Taq polymerase from the extremely thermophilic organism Thermus aquaticus has proven to be particularly suitable and can withstand brief heating to over 95 ° C. At 72 ° C, the polymerase supplements the DNA single strand between the two ends filled with primers to form the double strand.
• the three process steps namely heat denaturation, primer annealing and polymerization, can be repeated until the batch is exhausted. Since the amount of DNA is doubled in each individual step, a multiplication factor of about 10 is theoretically achieved after about 20 cycles.
• the primer pairs used are those from the fimA sequence with the designation Muta 1 and 2 (FIG. 1) and those from the focA sequence with the designation Muta 3 and 4 (FIG. 2) from the strain DSM 6601. These DNA sequences are partially in agreement with genes from other enterobacteria, but on the other hand there are bases at some positions that have not been observed in other enterobacteria.
• the other primer pairs Muta 5 and 6 (Fig. 3), Muta 7 and 8 and Muta 9 and 10 (Fig. 4) were derived from the DNA sequences of the plasmids pMUT 1 (Fig. 5) and pMUT 2 (Fig. 6) of the strain DSM 6601 selected. These primer pairs also have a nucleotide sequence that has not previously been found in enterobacteria. The sequences of the primers Muta 1 to Muta 10 are shown in detail in the attached Figures 1 to 4.
• a colony of E. coli strain DSM 6601 is inoculated from an agar plate and suspended in 100 ⁇ l bidistilled water. This suspension is heated to 95 ° C. for 10 minutes and then cooled on ice. 1 ⁇ ⁇ of the bacterial suspension is used as template DNA for the PCR.
• PCR reaction mixture is then pipetted into a PCR reaction tube:
• the steps b. to d. are repeated at least 20 times.
• the end products can then be used, for example, for the identification of Escherichia coli strain DSM 6601 or can also be sequenced in a manner known per se and used for checking correspondingly produced DNA sequences from E. coli strains to be examined.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
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• General Engineering & Computer Science (AREA)
• General Health & Medical Sciences (AREA)
• Genetics & Genomics (AREA)
• Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)

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• 1998
  • 1998-11-18 PL PL340330A patent/PL190847B1/pl unknown
  • 1998-11-18 CZ CZ20001873A patent/CZ289739B6/cs not_active IP Right Cessation
  • 1998-11-18 EP EP98966241A patent/EP1038035A1/de not_active Withdrawn
  • 1998-11-18 JP JP2000521233A patent/JP2004516801A/ja active Pending
  • 1998-11-18 EE EEP200000231A patent/EE200000231A/xx unknown
  • 1998-11-18 HU HU0004409A patent/HUP0004409A3/hu not_active Application Discontinuation
  • 1998-11-18 WO PCT/EP1998/007398 patent/WO1999025870A1/de not_active Application Discontinuation
  • 1998-11-18 US US09/554,724 patent/US6489107B1/en not_active Expired - Fee Related
• 2000
  • 2000-05-18 NO NO20002550A patent/NO20002550L/no unknown

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