A Sheep in Wolf's Clothing:
            <i>Listeria innocua</i>
            Strains with Teichoic Acid-Associated Surface Antigens and Genes Characteristic of
            <i>Listeria monocytogenes</i>
            Serogroup 4

Zheng, Lan; Fiedler, F.; Kathariou, Sophia

doi:10.1128/jb.182.21.6161-6168.2000

Cited by 34 publications

(37 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By these methods the species is divided into two genetic divisions which are correlated with the flagellar antigen groups division I, composed of strains of serotypes 1/2a and 1/2c, and division II, which is composed of strains of serotypes 1/2b and 4b. Both divisions are characterized by nonoverlapping allelic variants of different genetic markers, suggesting strong linkage disequilibrium and an apparent lack of gene exchange between them (15). This is consistent with the hypothesis that the genetic structure of L. monocytogenes populations is basically clonal (21).…”

supporting

confidence: 75%

Development of a Multilocus Sequence Typing Method for Analysis of Listeria monocytogenes Clones

et al. 2003

View full text Add to dashboard Cite

This study is a first step in the development of multilocus sequence typing (MLST) method for Listeria monocytogenes. Nine housekeeping genes were analyzed in a set of 62 strains isolated from different sources and geographic locations in Spain. These strains were previously characterized by pulsed-field gel electrophoresis (PFGE). Because of low diversity, two loci were discarded from the study. The sequence analysis of the seven remaining genes showed 29 different allelic combinations, with 22 of them represented by only one strain. The results of this sequence analysis were generally consistent with those of PFGE. Because MLST allows the easy comparison and exchange of results obtained in different laboratories, the future application of this new molecular method could be a useful tool for the listeriosis surveillance systems that will allow the identification and distribution of analysis of L. monocytogenes clones in the environment.Listeria monocytogenes is an opportunistic pathogen widely distributed in the environment. The ubiquity of this microorganism makes especially necessary the use of typing methods for the study of its epidemiology. Numerous molecular methods have been applied to the characterization of L. monocytogenes isolates, e.g., multilocus enzyme electrophoresis (MLEE) (1), pulsed-field gel electrophoresis (PFGE) (2, 29), random amplified polymorphic differences (19), and ribotyping (30), etc. By these methods the species is divided into two genetic divisions which are correlated with the flagellar antigen groups division I, composed of strains of serotypes 1/2a and 1/2c, and division II, which is composed of strains of serotypes 1/2b and 4b. Both divisions are characterized by nonoverlapping allelic variants of different genetic markers, suggesting strong linkage disequilibrium and an apparent lack of gene exchange between them (15). This is consistent with the hypothesis that the genetic structure of L. monocytogenes populations is basically clonal (21). Recently, an additional division has been proposed based on the variability of the sequence of several genes involved in virulence (22).MLEE has been the most widely used molecular method to study the genetic structure and epidemiology of pathogenic bacterial species. Recently, a novel molecular typing method based on the principles of MLEE (25) has been developed, multilocus sequence typing (MLST). This technique was primarily designed and validated for Neisseria meningitidis (17). Afterwards, it was successful in the characterization of several other pathogenic bacteria, such as Streptococcus pneumoniae (5), Streptococcus pyogenes (8), Staphylococcus aureus (7), and Campylobacter jejuni (4).MLST makes use of automated DNA sequencing to characterize the alleles present at different housekeeping genes.Because it is based on nucleotide sequence, it is highly discriminatory and provides unambiguous results that are directly comparable among laboratories via the internet (7). In addition, this method is particularly suited to global epidemiol...

show abstract

supporting

confidence: 75%

Development of a Multilocus Sequence Typing Method for Analysis of Listeria monocytogenes Clones

et al. 2003

View full text Add to dashboard Cite

show abstract

“…4). Evidence for horizontal transfer between L. monocytogenes serotype 4b and L. innocua has been described before (19). Alternatively, ORFs conserved in L. monocytogenes serotype 4b and L. innocua may represent ancestral sequences that have become eliminated from other L. monocytogenes lineages.…”

Section: Discussionmentioning

confidence: 99%

Genetic Markers Unique to Listeria monocytogenes Serotype 4b Differentiate Epidemic Clone II (Hot Dog Outbreak Strains) from Other Lineages

Evans

Swaminathan

Graves

et al. 2004

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

A small number of closely related strains of Listeria monocytogenes serotype 4b, designated epidemic clone I (ECI), have been implicated in numerous outbreaks of food-borne listeriosis described during the past two decades in Europe and North America. In 1998 to 1999, a multistate outbreak traced to contaminated hot dogs involved a different strain type of serotype 4b, with genetic fingerprints rarely encountered before. In spite of the profound economic and public health impact of this outbreak, the implicated bacteria (designated epidemic clone II [ECII]) have remained poorly characterized genetically, and nucleotide sequences specific for these strains have not been reported. Using genome sequence information, PCR, and Southern blots, we identified DNA fragments which appeared to be either absent or markedly divergent in the hot dog outbreak strains but conserved among other serotype 4b strains. PCR with primers derived from these fragments as well as Southern blots with the amplicons as probes readily differentiated ECII from other serotype 4b strains. The serotype 4b-specific region harboring these fragments was adjacent to inlA, which encodes a well-characterized virulence determinant. The findings suggest that ECII strains have undergone divergence in portions of a serotype-specific region that is conserved in other serotype 4b strains. Although the mechanisms that drive this divergence remain to be identified, DNA-based tools from this region can facilitate the detection and further characterization of strains belonging to this lineage.

show abstract

“…From there it could have been transferred to lineage I of L. innocua, as has been speculated for the gtcA locus recently identified in this lineage (9). The origin of the serotype-specific sequences may be elucidated by future identification of homologous sequences in other bacteria or bacteriophage.…”

Section: Discussionmentioning

confidence: 99%

“…Hybridizations using probe XL7-AB, which contains both gltA and gltB, showed that the genes were unique to L. monocytogenes serotype 4b-4d-4e and could not be detected in DNA from strains of other serotypes. The genes have also been detected in a unique lineage (lineage I) of L. innocua (9). EcoRI restriction fragment length polymorphisms using XL7-AB as the probe could differentiate between L. monocytogenes serotype 4b-4d-4e and L. innocua lineage I (Table 1).…”

Section: Vol 183 2001 Novel Serotype-specific Gene Cassette Of L Mmentioning

confidence: 96%

A Novel Serotype-Specific Gene Cassette ( gltA-gltB ) Is Required for Expression of Teichoic Acid-Associated Surface Antigens in Listeria monocytogenes of Serotype 4b

et al. 2001

Self Cite

View full text Add to dashboard Cite

Listeria monocytogenes serotype 4b strains account for about 40% of sporadic cases and many epidemics of listeriosis. Mutations in a chromosomal locus resulted in loss of reactivity with all three monoclonal antibodies (MAbs) which were specific to serotype 4b and the closely related serotypes 4d and 4e. Here we show that this locus contains a serotype 4b-4d-4e-specific gene cassette (3,071 bp) which consists of two genes, gltA and gltB, and is flanked by palindromic sequences (51 and 44 nucleotides). Complete loss of reactivity with the three serotype-specific MAbs resulted from insertional inactivation of either gltA or gltB. The gltA and gltB mutants were characterized by loss and severe reduction, respectively, of glucose in the teichoic acid, whereas galactose, the other serotype-specific sugar substituent in the teichoic acid, was not affected. Within L. monocytogenes, only strains of serotypes 4b, 4d, and 4e harbored the gltA-gltB cassette, whereas coding sequences on either side of the cassette were conserved among all serotypes. Comparative genomic analysis of a serotype 1/2b strain showed that the 3,071-bp gltA-gltB cassette was replaced by a much shorter (528-bp) and unrelated region, flanked by inverted repeats similar to their counterparts in serotype 4b. These findings indicate that in the evolution of different serotypes of L. monocytogenes, this site in the genome has become occupied by serotypespecific sequences which, in the case of serotype 4b, are essential for expression of serotype-specific surface antigens and presence of glucose substituents in the teichoic acids in the cell wall.

show abstract

A Sheep in Wolf's Clothing: Listeria innocua Strains with Teichoic Acid-Associated Surface Antigens and Genes Characteristic of Listeria monocytogenes Serogroup 4

Cited by 34 publications

References 30 publications

Development of a Multilocus Sequence Typing Method for Analysis of Listeria monocytogenes Clones

Development of a Multilocus Sequence Typing Method for Analysis of Listeria monocytogenes Clones

Genetic Markers Unique to Listeria monocytogenes Serotype 4b Differentiate Epidemic Clone II (Hot Dog Outbreak Strains) from Other Lineages

A Novel Serotype-Specific Gene Cassette ( gltA-gltB ) Is Required for Expression of Teichoic Acid-Associated Surface Antigens in Listeria monocytogenes of Serotype 4b

Contact Info

Product

Resources

About