scholarly journals DNA Probes for Unambiguous Identification of Listeria monocytogenes Epidemic Clone II Strains

2010 ◽  
Vol 76 (9) ◽  
pp. 3061-3068 ◽  
Author(s):  
Ying Cheng ◽  
J.-W. Kim ◽  
S. Lee ◽  
R. M. Siletzky ◽  
S. Kathariou
Keyword(s):  
United States ◽  
Listeria Monocytogenes ◽  
The United States ◽  
Dna Probes ◽  
Epidemic Clone ◽  
Clonal Group ◽  
Food Borne ◽  
Serotype 4B

ABSTRACT Listeria monocytogenes epidemic clone II (ECII) strains have been responsible for two major multistate outbreaks of food-borne listeriosis in the United States, but their prevalence and ecology remain poorly understood. In this study, we describe DNA probes that unambiguously identify this clonal group. These probes were able to differentiate ECII strains of outbreak, sporadic, or environmental origin from other L. monocytogenes strains of the same serotype (4b).

scholarly journals Population Structure of Listeria monocytogenes Serotype 4b Isolates from Sporadic Human Listeriosis Cases in the United States from 2003 to 2008

2014 ◽  
Vol 80 (12) ◽  
pp. 3632-3644 ◽  
Author(s):  
Sangmi Lee ◽  
Todd J. Ward ◽  
Lewis M. Graves ◽  
Cheryl L. Tarr ◽  
Robin M. Siletzky ◽  
...  
Keyword(s):  
United States ◽  
Population Structure ◽  
Listeria Monocytogenes ◽  
The United States ◽  
Content Type ◽  
Food Borne ◽  
Complex Population ◽  
Sporadic Cases ◽  
Long Term Trends ◽  
Serotype 4B

ABSTRACTListeria monocytogenescan cause severe food-borne disease (listeriosis). Numerous outbreaks have involved three serotype 4b epidemic clones (ECs): ECI, ECII, and ECIa. However, little is known about the population structure ofL. monocytogenesserotype 4b from sporadic listeriosis in the United States, even though most cases of human listeriosis are in fact sporadic. Here we analyzed 136 serotype 4b isolates from sporadic cases in the United States, 2003 to 2008, utilizing multiple tools including multilocus genotyping, pulsed-field gel electrophoresis, and sequence analysis of theinlABlocus. ECI, ECII, and ECIa were frequently encountered (32, 17, and 7%, respectively). However, annually 30 to 68% of isolates were outside these ECs, and several novel clonal groups were identified. An estimated 33 and 17% of the isolates, mostly among the ECs, were resistant to cadmium and arsenic, respectively, but resistance to benzalkonium chloride was uncommon (3%) among the sporadic isolates. The frequency of clonal groups fluctuated within the 6-year study period, without consistent trends. However, on several occasions, temporal clusters of isolates with indistinguishable genotypes were detected, suggesting the possibility of hidden multistate outbreaks. Our analysis suggests a complex population structure of serotype 4bL. monocytogenesfrom sporadic disease, with important contributions by ECs and several novel clonal groups. Continuous monitoring will be needed to assess long-term trends in clonality patterns and population structure ofL. monocytogenesfrom sporadic listeriosis.

scholarly journals Temperature-Dependent Phage Resistance of Listeria monocytogenes Epidemic Clone II

2009 ◽  
Vol 75 (8) ◽  
pp. 2433-2438 ◽  
Author(s):  
Jae-Won Kim ◽  
Sophia Kathariou
Keyword(s):  
Listeria Monocytogenes ◽  
The United States ◽  
Phage Resistance ◽  
Processing Plant ◽  
Broad Host Range ◽  
Temperature Dependent ◽  
Cadmium Resistance ◽  
Epidemic Clone ◽  
Plant Environment ◽  
Serotype 4B

ABSTRACT Listeria monocytogenes epidemic clone II (ECII) has been responsible for two multistate outbreaks in the United States in 1998-1999 and in 2002, in which contaminated ready-to-eat meat products (hot dogs and turkey deli meats, respectively) were implicated. However, ecological adaptations of ECII strains in the food-processing plant environment remain unidentified. In this study, we found that broad-host-range phages, including phages isolated from the processing plant environment, produced plaques on ECII strains grown at 37°C but not when the bacteria were grown at lower temperatures (30°C or below). ECII strains grown at lower temperatures were resistant to phage regardless of the temperature during infection and subsequent incubation. In contrast, the phage susceptibility of all other tested strains of serotype 4b (including epidemic clone I) and of strains of other serotypes and Listeria species was independent of the growth temperature of the bacteria. This temperature-dependent phage susceptibility of ECII bacteria was consistently observed with all surveyed ECII strains from outbreaks or from processing plants, regardless of the presence or absence of cadmium resistance plasmids. Phages adsorbed similarly on ECII bacteria grown at 25°C and at 37°C, suggesting that resistance of ECII strains grown at 25°C was not due to failure of the phage to adsorb. Even though the underlying mechanisms remain to be elucidated, temperature-dependent phage resistance may represent an important ecological adaptation of L. monocytogenes ECII in processed, cold-stored foods and in the processing plant environment, where relatively low temperatures prevail.

scholarly journals Conservation of Genomic Localization and Sequence Content of Sau3AI-Like Restriction-Modification Gene Cassettes among Listeria monocytogenes Epidemic Clone I and Selected Strains of Serotype 1/2a

2010 ◽  
Vol 76 (16) ◽  
pp. 5577-5584 ◽  
Author(s):  
Suleyman Yildirim ◽  
Driss Elhanafi ◽  
Wen Lin ◽  
Anthony D. Hitchins ◽  
Robin M. Siletzky ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gene Cassette ◽  
Conclusive Evidence ◽  
Gene Encoding ◽  
Epidemic Clone ◽  
Food Borne ◽  
Serotype 1 ◽  
Serotype 4B ◽  
Clonal Population Structure ◽  
Restriction Modification

ABSTRACTListeria monocytogenesis a food-borne pathogen with a clonal population structure and apparently limited gene flow between strains of different lineages. Strains of epidemic clone I (ECI) have been responsible for numerous outbreaks and invariably have DNA that is resistant to digestion by Sau3AI, suggesting methylation of cytosine at GATC sites. A putative restriction-modification (RM) gene cassette has been identified in the genome of the ECI strain F2365 and all other tested ECI strains but is absent from other strains of the same serotype (4b). Homologous RM cassettes have not been reported amongL. monocytogenesisolates of other serotypes. Furthermore, conclusive evidence for the involvement of this RM cassette in the Sau3AI resistance phenotype of ECI strains has been lacking. In this study, we describe a highly conserved RM cassette in certain strains of serotypes 1/2a and 4a that have Sau3AI-resistant DNA. In these strains the RM cassette was in the same genomic location as in the ECI reference strain F2365. The cassette included a gene encoding a putative recombinase, suggesting insertion via site-specific recombination. Deletion of the RM cassette in the ECI strain F2365 and the serotype 1/2a strain A7 rendered the DNA of both strains susceptible to Sau3AI digestion, providing conclusive evidence that the cassette includes a gene required for methylation of cytosine at GATC sites in both strains. The findings suggest that, in addition to its presence in ECI strains, this RM cassette and the accompanying genomic DNA methylation is also encountered among selected strains of other lineages.

scholarly journals Relatedness of Listeria monocytogenes Isolates Recovered from Selected Ready-To-Eat Foods and Listeriosis Patients in the United States

2005 ◽  
Vol 71 (12) ◽  
pp. 8115-8122 ◽  
Author(s):  
Stefanie Evans Gilbreth ◽  
Jeff E. Call ◽  
F. Morgan Wallace ◽  
Virginia N. Scott ◽  
Yuhuan Chen ◽  
...  
Keyword(s):  
United States ◽  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Food Products ◽  
The United States ◽  
Pulsed Field Gel Electrophoresis ◽  
Clinical Isolates ◽  
Pulsed Field ◽  
Serotype 1 ◽  
Serotype 4B

ABSTRACT Pulsed-field gel electrophoresis and serotyping were performed for 544 isolates of Listeria monocytogenes, including 502 isolates recovered from contaminated samples from 31,705 retail ready-to-eat (RTE) food products and 42 isolates recovered from human cases of listeriosis. The isolates were from Maryland (294 isolates) and California (250 isolates) and were collected in 2000 and 2001. The isolates were placed into 16 AscI pulsogroups (level of relatedness within each group, ≥66%), 139 AscI pulsotypes (levels of relatedness, ≥25% to 100%), and eight serotypes (serotypes 1/2a, 1/2b, 1/2c, 3a, 3b, 4b, 4c, and 4d). The most frequently found pulsotypes belonged to either pulsogroup A (150 food isolates plus 4 clinical isolates) or pulsogroup B (104 food isolates plus 5 clinical isolates). The majority of the 502 food isolates were either serotype 1/2a (298 isolates) or serotype 1/2b (133 isolates), whereas the majority of the 42 clinical isolates were either serotype 1/2a (19 isolates) or serotype 4b (15 isolates). Additionally, 13 clinical isolates displayed pulsotypes also found in food isolates, whereas the remaining 29 clinical isolates displayed 24 unique pulsotypes. These data indicate that most (86%) of the L. monocytogenes subtypes found in the RTE foods sampled belonged to only two serotypes and that 90% of the isolates displayed 73 pulsotypes, with 107 isolates displaying pulsotype 1. These data should help define the distribution and relatedness of isolates found in RTE foods in comparison with isolates that cause listeriosis.

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

2004 ◽  
Vol 70 (4) ◽  
pp. 2383-2390 ◽  
Author(s):  
Matthew R. Evans ◽  
Bala Swaminathan ◽  
Lewis M. Graves ◽  
Eric Altermann ◽  
Todd R. Klaenhammer ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Health Impact ◽  
Specific Region ◽  
Sequence Information ◽  
Epidemic Clone ◽  
Southern Blots ◽  
Food Borne ◽  
Genome Sequence Information ◽  
Serotype 4B ◽  
Hot Dog

ABSTRACT 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.

scholarly journals Epidemic Clone I-Specific Genetic Markers in Strains of Listeria monocytogenes Serotype 4b from Foods

2004 ◽  
Vol 70 (7) ◽  
pp. 4158-4164 ◽  
Author(s):  
Suleyman Yildirim ◽  
Wen Lin ◽  
Anthony D. Hitchins ◽  
Lee-Ann Jaykus ◽  
Eric Altermann ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Genetic Markers ◽  
Food Processing ◽  
Gene Cassette ◽  
Epidemic Clone ◽  
Modification System ◽  
Restriction Modification System ◽  
Food Borne ◽  
Serotype 4B ◽  
Restriction Modification

ABSTRACT Listeria monocytogenes contamination of ready-to-eat foods has been implicated in numerous outbreaks of food-borne listeriosis. However, the health hazards posed by L. monocytogenes detected in foods may vary, and speculations exist that strains actually implicated in illness may constitute only a fraction of those that contaminate foods. In this study, examination of 34 serogroup 4 (putative or confirmed serotype 4b) isolates of L. monocytogenes obtained from various foods and food-processing environments, without known implication in illness, revealed that many of these strains had methylation of cytosines at GATC sites in the genome, rendering their DNA resistant to digestion by the restriction endonuclease Sau3AI. These strains also harbored a gene cassette with putative restriction-modification system genes as well as other, genomically unlinked genetic markers characteristic of the major epidemic-associated lineage of L. monocytogenes (epidemic clone I), implicated in numerous outbreaks in Europe and North America. This may reflect a relatively high fitness of strains with these genetic markers in foods and food-related environments relative to other serotype 4b strains and may partially account for the repeated involvement of such strains in human food-borne listeriosis.

Food-Borne Disease Outbreaks in the United States, 1973

1975 ◽  
Vol 132 (2) ◽  
pp. 224-228 ◽  
Author(s):  
J. M. Hughes ◽  
M. H. Merson ◽  
R. A. Pollard
Keyword(s):  
United States ◽  
Disease Outbreaks ◽  
The United States ◽  
Food Borne

Listeria monocytogenes in Raw Milk: Detection, Incidence, and Pathogenicity

1987 ◽  
Vol 50 (3) ◽  
pp. 188-192 ◽  
Author(s):  
J. LOVETT ◽  
D. W. FRANCIS ◽  
J. M. HUNT
Keyword(s):  
United States ◽  
Listeria Monocytogenes ◽  
Sampling Period ◽  
Raw Milk ◽  
The United States ◽  
Isolation Method ◽  
Listeria Species ◽  
Adult Mice ◽  
Listeria Ivanovii

To determine the incidence of Listeria monocytogenes in raw milk, an isolation method was evaluated and used to analyze milk from three areas of the United States. The incidence varied by area from 0% in California to 7% in Massachusetts, with an overall incidence of 4.2%. The highest incidence found in any area during a single sampling period was 12% in Massachusetts in March 1985. During that same sampling, the incidence for all Listeria species was 26%. Of the 27 L. monocytogenes strains isolated during the survey, 25 were pathogenic in adult mice. One of three Listeria ivanovii isolated was pathogenic. No other isolates demonstrated pathogenicity.

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