Detection of listeria

Claim 2

A nucleic acid fragment capable of hybridizing, under predetermined stringency conditions, to rRNA of Listeria monocytogenes and not to rRNA of Bacillus subtilis..

Claim 3

The nucleic acid fragment of claim 1 wherein said fragment is not capable of hybridizing, under said conditions, to rRNA of Aeromonas sobria , Bacillus cereus , Bacillus subtilis , Brochothrix thermosphacta , Citrobacter freundii , Corynebacterium xerosis , Corynebacterium diptheriae , Escerichia vulneris , Enterobacter agglomerans , Enterobacter cloacae , Klebsiella pneumoniae , Klebsilla oxytoca , Lactobacillus casei , Pseudomonas aeruginosa , Rhodococcus equii , Salmonella arizonae , Salmonella cholerae-suis , Salmonella typhi , Serratia odorifera , Shigella bovdii , Shigella flexneri , Shigella sonnei , Staphylococcus aureus , Staphylococcus epidermidis , Staphylococcus hominis , Staphylococcus saprophyticus , Streptococcus agalacticae , Streptococcus bovis , Streptococcus faecalis , Streptococcus faecium , Streptococcus lactis , Streptococcus mutans , Streptococcus pneumoniae , Streptomyces globisporus , Yersinia enterocolitica .

Claim 4

A set of nucleic acid fragments comprising a first nucleic acid fragment capable of hybridizing to rRNA of a first Listeria species and not to rRNA of B. subtilis or to rRNA of a second Listeria species, and a second nucleic acid fragment capable of hybridizing to rRNA of said second Listeria species and not to rRNA of B. subtilis .

Claim 5

A set of nucleic acid fragments comprising a first nucleic acid fragment capable of hybridizing to rRNA of a first Listeria species and not to rRNA of B. subtilis or to rRNA of a second Listeria species, and a second nucleic acid fragment capable of hybridizing to rRNA of said second Listeria species and not to rRNA of B. subtilis .

Claim 6

The set of nucleic acid fragments of claim 3, said fragments together being capable of hybridizing to at least 80% of Listeria strains.

Claim 7

The nucleic acid fragment of claim 1, said fragments being capable of hybridizing under hybridizing conditions to probe 568 or its complementary strand.

Claim 8

The nucleic acid fragment of claim 1, said fragments being capable of hybridizing under hybridizing conditions to probe 661 or its complementary strand.

Claim 9

The nucleic acid fragment of claim 1, said fragment being homologous with at least 75% of a 10 nucleotide or larger region of one of the five Listeria 16S rRNA regions shown in the Fiqure.

Claim 10

A method of detecting the presence of Listeria bacteria in a sample, comprising contacting the nucleic acid fragment of claim 1 with bacteria in said sample under conditions that allow said fragment to hybridize to rRNA of said Listeria bacteria in said sample to form hybrid nucleic acid complexes, and detecting said hybrid complexes as an indication of the presence of said Listeria bacteria in said sample.

Claim 11

The method of claim 8 comprising culturing bacteria in said sample under culture conditions which allow growth of Listeria but not of Brochothrix .

Claim 12

The method of claim 9 wherein said culture conditions is a growth temperature above 30° C.

Claim 15

The method of claim 8 wherein, prior to said contacting, said sample is subjected to a primary enrichment step for Listeria , followed by a secondary, non-specific bacterial enrichment step, said secondary enrichment step being carried out in a buffer solution to maintain the pH of said enriched sample between 6.5 and 8.0.

Claim 16

The method of claim 12 wherein said pH is maintained at about 7.2

Claim 17

The method of claim 8 wherein, prior to said contacting, Listeria in said sample are contacted with an enzyme to weaken their cell walls, and are then lysed.

Claim 18

A set of nucleic acid fragments derived from Listeria and having nucleotide sequences as shown in the accompanying drawings.

Claim 19

A set of nucleic acid fragments derived from Listeria and having nucleotide sequences as shown in the accompanying drawings.

Claim 20

A nucleic acid fragment derived from Listeria and having any of the nucleotide sequences shown in the accompanying drawings.

Claim 21

A nucleic acid fragment derived from Listeria and having any of the nucleotide sequences shown in the accompanying drawings.