Probe for DNA and a process for the detection of "shigellae" and entero-invasive strains of Escherichia coli

Claim 2

A kit for the detection of virulent Shigellae and entero-invasive Escherichia coli microorganisms, wherein the kit comprises: (A) a container means containing a probe comprising a nucleic acid sequence which is present in a 140 Mdal virulence plasmid of a M 90 T strain of Shigellae flexneri, wherein said nucleic acid sequence has a maximum size of about 27 kb and the nucleic acid sequence includes all or part of a 27 kb BamHI fragment of said 140 Mdal plasmid and a 17 kb EcoRI fragment of said 140 Mdal plasmid, wherein said 17 kb fragment has a part in common with said BamHI fragment: and (B) a container means containing a control preparation of nucleic acid of an avirulent strain of a microorganism or of nucleic acid of a stool from a healthy individual.

Claim 3

A process for detecting in vitro the presence of a cell of a virulent Shigellae or entero-invasive Escherichia coli, wherein the process comprises the steps of: (A) depositing and fixing nucleic acids of the cell on a filter, so as to make the nucleic acids accessible to a probe; (B) contacting said fixed nucleic acids from step (A) with a labelled probe under conditions permitting hybridization; (C) washing said filter resulting from step (B), so as to eliminate any non-hybridized probe; and then (D) detecting any hybridized probe on said washed filter resulting from step (C); wherein said labelled probe comprises: a nucleic acid sequence which is present in a 140 Mdal virulence plasmid of a M 90 T strain of Shigellae flexneri, wherein said nucleic acid sequence has a maximum size of about 27 kb, and the nucleic acid sequence includes all or part of a 27 kb BamHI fragment of said 140 Mdal plasmid and a 17 kb EcoRI fragment of said 140 Mdal plasmid, wherein said 17 kb fragment has a part in common with said 27 kb BamHI fragment; and wherein the probe has a label selected from the group consisting of radioactive, enzymatic, fluorescent, and luminescent labels.

Claim 4

A process for detecting in vitro the presence of a cell of a virulent Shigellae or entero-invasive Escherichia coli, wherein the process comprises the steps of: (A) depositing and fixing nucleic acids of the cell on a filter, so as to make the nucleic acids accessible to a probe; (B) contacting said fixed nucleic acids from step (A) with a labelled probe under conditions permitting hybridization; (C) washing said filter resulting from step (B), so as to eliminate any non-hybridized probe; and then (D) detecting any hybridized probe on said washed filter resulting from step (C); wherein said labelled probe comprises: a nucleic acid sequence which is present in a 140 Mdal virulence plasmid of a M 90 T strain of Shigellae flexneri, wherein said nucleic acid sequence has a maximum size of about 27 kb, and the nucleic acid sequence includes all or part of a 27 kb BamHI fragment of said 140 Mdal plasmid and a 17 kb EcoRI fragment of said 140 Mdal plasmid, wherein said 17 kb fragment has a part in common with said 27 kb BamHI fragment; and wherein the probe has a label selected from the group consisting of radioactive, enzymatic, fluorescent, and luminescent labels.