scholarly journals Heavy-Metal and Benzalkonium Chloride Resistance of Listeria monocytogenes Isolates from the Environment of Turkey-Processing Plants

2008 ◽  
Vol 74 (5) ◽  
pp. 1464-1468 ◽  
Author(s):  
S. Mullapudi ◽  
R. M. Siletzky ◽  
S. Kathariou
Keyword(s):  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Food Processing ◽  
Benzalkonium Chloride ◽  
The United States ◽  
Limited Information ◽  
Chloride Resistance ◽  
Processing Plants ◽  
Serotype 1 ◽  
Serotype 4B

ABSTRACT The resistance of Listeria monocytogenes to cadmium and arsenic has been used extensively for strain subtyping. However, limited information is available on the prevalence of such resistance among isolates from the environment of food-processing plants. In addition, it is not known whether the resistance of such isolates to heavy metals may correlate with resistance to quaternary ammonium compounds extensively used as disinfectants in the food-processing industry. In this study, we characterized 192 L. monocytogenes isolates (123 putative strains) from the environment of turkey-processing plants in the United States for resistance to cadmium and arsenic and to the quaternary ammonium disinfectant benzalkonium chloride (BC). Resistance to cadmium was significantly more prevalent among strains of serotypes 1/2a (or 3a) and 1/2b (or 3b) (83% and 74%, respectively) than among strains of the serotype 4b complex (19%). Resistance to BC was encountered among 60% and 51% of the serotype 1/2a (or 3a) and 1/2b (or 3b) strains, respectively, and among 7% of the strains of the serotype 4b complex. All BC-resistant strains were also resistant to cadmium, although the reverse was not always the case. In contrast, no correlation was found between BC resistance and resistance to arsenic, which overall was low (6%). Our findings suggest that the processing environment of turkey-processing plants may constitute a reservoir for L. monocytogenes harboring resistance to cadmium and to BC and raise the possibility of common genetic elements or mechanisms mediating resistance to quaternary ammonium disinfectants and to cadmium in L. monocytogenes.

scholarly journals Conservation and Distribution of the Benzalkonium Chloride Resistance CassettebcrABCin Listeria monocytogenes

2013 ◽  
Vol 79 (19) ◽  
pp. 6067-6074 ◽  
Author(s):  
Vikrant Dutta ◽  
Driss Elhanafi ◽  
Sophia Kathariou
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Benzalkonium Chloride ◽  
Clinical Environment ◽  
Outbreak Strain ◽  
Content Type ◽  
Chloride Resistance ◽  
Processing Plants ◽  
Hot Dog ◽  
Widespread Dissemination

ABSTRACTAnalysis of a panel of 116Listeria monocytogenesstrains of diverse serotypes and sources (clinical, environment of food processing plants, and food) revealed that all but one of the 71 benzalkonium chloride-resistant (BCr) isolates harboredbcrABC, previously identified on a large plasmid (pLM80) of the 1998-1999 hot dog outbreak strain H7858. In contrast,bcrABCwas not detected among BC-susceptible (BCs) isolates. ThebcrABCsequences were highly conserved among strains of different serotypes, but variability was noted in sequences flankingbcrABC. The majority of the BCrisolates had either the pLM80-type of organization of thebcrABCregion or appeared to harborbcrABCon the chromosome, adjacent to novel sequences. Transcription ofbcrABCwas induced by BC (10 μg/ml) in strains of different serotypes and diversebcrABCregion organization. These findings reveal widespread dissemination ofbcrABCacross BCrL. monocytogenesstrains regardless of serotype and source, while also suggesting possible mechanisms ofbcrABCdissemination acrossL. monocytogenesgenomes.

Formation of Biofilm at Different Nutrient Levels by Various Genotypes of Listeria monocytogenes

2006 ◽  
Vol 69 (4) ◽  
pp. 826-834 ◽  
Author(s):  
JAMES P. FOLSOM ◽  
GREGORY R. SIRAGUSA ◽  
JOSEPH F. FRANK
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Hoechst 33258 ◽  
Genetic Subtype ◽  
Processing Plants ◽  
Serotype 1 ◽  
Serotype 4B ◽  
Different Strains ◽  
Element Sequence ◽  
Range Test

Strains of Listeria monocytogenes differ in their ability to form biofilms. The objectives of this study were to determine whether genetically related strains have similar biofilm-forming capacities and what effect nutrient concentration has on the ability of different strains to produce biofilms. Biofilms of 30 strains of L. monocytogenes, obtained from a variety of sources were grown on stainless steel in tryptic soy broth (TSB) or in a 1:10 dilution of TSB (DTSB) for 24 h at 32°C. The amount of biofilm formed was determined with image analysis after cells were stained with bisBenzimide H 33258 (Hoechst 33258). The strains were genetically subtyped by repetitive element sequence–based PCR (rep-PCR) with the primer set rep-PRODt and rep-PROG5. Data were analyzed with an analysis of variance and Duncan's multiple range test. Eleven strains produced the same amount of biofilm in both media. Fourteen strains produced more biofilm in TSB than in DTSB. Five strains produced more biofilm in DTSB than in TSB. Serotype 4b strains produced more biofilm in TSB than did serotype 1/2a strains, whereas serotype 1/2a strains produced more biofilm in DTSB than did serotype 4b strains. Growth in DTSB resulted in decreased biofilm accumulation for serotype 4b strains. There was no correlation between genetic subtype and the amount of biofilm accumulation. These results indicate that strains of serotype 1/2a and serotype 4b differ in the regulation of their biofilm phenotype. The poor biofilm accumulation of serotype 4b isolates when grown in DTSB could be a factor in the predominance of serogroup 1/2 strains in food processing plants, where nutrients may be limited.

scholarly journals Genetic Characterization of Plasmid-Associated Benzalkonium Chloride Resistance Determinants in a Listeria monocytogenes Strain from the 1998-1999 Outbreak

2010 ◽  
Vol 76 (24) ◽  
pp. 8231-8238 ◽  
Author(s):  
Driss Elhanafi ◽  
Vikrant Dutta ◽  
Sophia Kathariou
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Benzalkonium Chloride ◽  
Genetic Basis ◽  
Genetic Characterization ◽  
Chloride Resistance ◽  
Processing Plants ◽  
Resistant Strains ◽  
Ammonium Compounds

ABSTRACT Quaternary ammonium compounds such as benzalkonium chloride (BC) are widely used as disinfectants in both food processing and medical environments. BC-resistant strains of Listeria monocytogenes have been implicated in multistate outbreaks of listeriosis and have been frequently isolated from food processing plants. However, the genetic basis for BC resistance in L. monocytogenes remains poorly understood. In this study, we have characterized a plasmid (pLM80)-associated BC resistance cassette in L. monocytogenes H7550, a strain implicated in the 1998-1999 multistate outbreak involving contaminated hot dogs. The BC resistance cassette (bcrABC) restored resistance to BC (MIC, 40 μg/ml) in a plasmid-cured derivative of H7550. All three genes of the cassette were essential for imparting BC resistance. The transcription of H7550 BC resistance genes was increased under sublethal (10 μg/ml) BC exposure and was higher at reduced temperatures (4, 8, or 25°C) than at 37°C. The level of transcription was higher at 10 μg/ml than at 20 or 40 μg/ml. In silico analysis suggested that the BC resistance cassette was harbored by an IS1216 composite transposon along with other genes whose functions are yet to be determined. The findings from this study will further our understanding of the adaptations of this organism to disinfectants such as BC and may contribute to the elucidation of possible BC resistance dissemination in L. monocytogenes.

scholarly journals Heavy Metal and Disinfectant Resistance of Listeria monocytogenes from Foods and Food Processing Plants

2012 ◽  
Vol 78 (19) ◽  
pp. 6938-6945 ◽  
Author(s):  
Shakir S. Ratani ◽  
Robin M. Siletzky ◽  
Vikrant Dutta ◽  
Suleyman Yildirim ◽  
Jason A. Osborne ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Listeria Monocytogenes ◽  
Food Processing ◽  
Cadmium Resistance ◽  
Content Type ◽  
Ecological History ◽  
Resistance Determinants ◽  
Processing Plants ◽  
History Of ◽  
Serotype 4B

ABSTRACTThe persistence ofListeria monocytogenesin food processing plants and other ecosystems reflects its ability to adapt to numerous stresses. In this study, we investigated 138 isolates from foods and food processing plants for resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) and to heavy metals (cadmium and arsenic). We also determined the prevalence of distinct cadmium resistance determinants (cadA1,cadA2, andcadA3) among cadmium-resistant isolates. Most BC-resistant isolates were resistant to cadmium as well. Arsenic resistance was encountered primarily in serotype 4b and was an attribute of most isolates of the serotype 4b epidemic clonal group ECIa. Prevalence of the known cadmium resistance determinants was serotype associated:cadA1was more common in isolates of serotypes 1/2a and 1/2b than 4b, whilecadA2was more common in those of serotype 4b. A subset (15/77 [19%]) of the cadmium-resistant isolates lacked the known cadmium resistance determinants. Most of these isolates were of serotype 4b and were also resistant to arsenic, suggesting novel determinants that may confer resistance to both cadmium and arsenic in these serotype 4b strains. The findings may reflect previously unrecognized components of the ecological history of different serotypes and clonal groups ofL. monocytogenes, including exposures to heavy metals and disinfectants.

Pathogenicity of Food and Clinical Listeria monocytogenes Isolates in a Mouse Bioassay

2003 ◽  
Vol 66 (12) ◽  
pp. 2362-2366 ◽  
Author(s):  
KAZUE TAKEUCHI ◽  
MARY ALICE SMITH ◽  
MICHAEL P. DOYLE
Keyword(s):  
Listeria Monocytogenes ◽  
Raw Milk ◽  
The United States ◽  
Clinical Samples ◽  
Mouse Bioassay ◽  
Factors Affecting ◽  
Serotype 1 ◽  
Horse Blood ◽  
Serotype 4B ◽  
Immunocompromised Mice

Serotype distributions of Listeria monocytogenes in clinical samples and foods often differ. It is unknown whether such differences reflect a variation in the virulence of strains or are due to other factors that are not directly related to the strains' ability to cause illnesses. Fifty-two food and eight clinical isolates of L. monocytogenes were obtained from France, Japan, and the United States. Their pathogenicity in nonimmunocompromised female ICR mice was determined by intraperitoneal (i.p.) injection of the mice with test strains at 108 to 109 CFU per mouse. Five mice were injected with each Listeria strain and observed for 5 days. Listeria isolates that caused at least one death in 5 days were considered pathogenic. Isolates that caused no deaths in 5 days were considered nonpathogenic. All strains except Listeria innocua and one L. monocytogenes serotype 4b strain (RM3-1) isolated from bovine raw milk were pathogenic to nonimmunocompromised mice. Three food isolates of L. monocytogenes serotype 1/2c were weakly pathogenic to nonimmunocompromised mice, killing a maximum of 50% of mice at 108 CFU. Strains with no pathogenicity or reduced pathogenicity were further tested for their pathogenicity to immunocompromised mice. Each strain was inoculated i.p. into five mice at 103 to 1010 CFU per mouse. No deaths of immunocompromised mice inoculated with 108 CFU were observed, but 20 to 40% of the mice died when inoculated with 109 CFU of L. monocytogenes RM3-1. The three L. monocytogenes serotype 1/2c isolates were also weakly pathogenic to immunocompromised mice, with two of the three isolates killing ≤60% of mice at doses of ≤108 CFU. The hemolytic activity of the three weakly pathogenic serotype 1/2c isolates was similar to that of pathogenic strains. However, the nonpathogenic strain RM3-1 was not found to be hemolytic on horse blood agar. We have identified several L. monocytogenes strains with reduced virulence levels. Further characterization of such isolates may aid in understanding factors affecting the variation in virulence among strains.

scholarly journals Harnessing Whole Genome Sequence Data for Facility-Specific Signatures for Listeria monocytogenes: A Case Study With Turkey Processing Plants in the United States

2021 ◽  
Vol 5 ◽  
Author(s):  
Phillip Brown ◽  
Yi Chen ◽  
Robin Siletzky ◽  
Cameron Parsons ◽  
Lee-Ann Jaykus ◽  
...  
Keyword(s):  
United States ◽  
Listeria Monocytogenes ◽  
Food Processing ◽  
Sequence Data ◽  
Allelic Variation ◽  
The United States ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Molecular Signatures ◽  
Processing Plants

Listeria monocytogenes is a Gram-positive foodborne pathogen responsible for the severe disease listeriosis and notorious for its ability to persist in food processing plants, leading to contamination of processed, ready-to-eat foods. L. monocytogenes persistence in various food processing environments (FPEs) has been extensively investigated by various subtyping tools, with increasing use of whole genome sequencing (WGS). However, major knowledge gaps remain. There is a need for facility-specific molecular signatures not only for adequate attribution of L. monocytogenes to a specific FPE but also for improved understanding of the ecology and evolution of L. monocytogenes in the food processing ecosystem. Furthermore, multiple strains can be recovered from a single FPE sample, but their diversity can be underestimated with common molecular subtyping tools. In this study we investigated a panel of 54 L. monocytogenes strains from four turkey processing plants in the United States. A combination of WGS and phenotypic assays was employed to assess strain persistence as well as identify facility-specific molecular signatures. Comparative analysis of allelic variation across the whole genome revealed that allelic profiles have the potential to be specific to individual processing plants. Certain allelic profiles remained associated with individual plants even when closely-related strains from other sources were included in the analysis. Furthermore, for certain sequence types (STs) based on the seven-locus multilocus sequence typing scheme, presence and location of premature stop codons in inlA, inlB length, prophage sequences, and the sequence content of a genomic hotspot could serve as plant-specific signatures. Interestingly, the analysis of different isolates from the same environmental sample revealed major differences not only in serotype and ST, but even in the sequence content of strains of the same ST. This study highlights the potential for WGS data to be deployed for identification of facility-specific signatures, thus facilitating the tracking of strain movement through the food chain. Furthermore, deployment of WGS for intra-sample strain analysis allows for a more complete environmental surveillance of L. monocytogenes in food processing facilities, reducing the risk of failing to detect strains that may be clinically relevant and potentially novel.

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 Competitive Fitness of Listeria monocytogenes Serotype 1/2a and 4b Strains in Mixed Cultures with and without Food in the U.S. Food and Drug Administration Enrichment Protocol

2006 ◽  
Vol 72 (1) ◽  
pp. 776-783 ◽  
Author(s):  
Lisa Gorski ◽  
Denise Flaherty ◽  
Robert E. Mandrell
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
Mixed Cultures ◽  
Genetic Lineage ◽  
Processing Plants ◽  
Serotype 1 ◽  
Enrichment Protocol ◽  
Serotype 4B ◽  
The U.S

ABSTRACT Thirteen different serotypes of the food-borne pathogen Listeria monocytogenes have been described. Serotype 4b strains are most often associated with illness, and serotype 1/2a strains are most often isolated from foods and processing plants. Different abilities to respond to stresses have been described for serotype 4b and 1/2a strains. One of the common enrichment protocols used to test foods for the presence L. monocytogenes is described in the U.S. Food and Drug Administration (FDA) Bacterial Analytical Manual (BAM). We compared three strains of L. monocytogenes serotype 4b and five strains of serotype 1/2a in direct competition with each other in two-strain mixed cultures by using the FDA BAM enrichment protocol, which includes both enrichment broth and selective agar, with and without added food to mimic the conditions that occur during attempts to isolate Listeria species from contaminated foods. Using a colony immunoblot procedure and analyzing over 112,000 colonies, we observed differences in strain fitness, but these differences were not attributable to serotype or genetic lineage.

scholarly journals Multilocus Sequence Typing of Listeria monocytogenes by Use of Hypervariable Genes Reveals Clonal and Recombination Histories of Three Lineages

2004 ◽  
Vol 70 (4) ◽  
pp. 2193-2203 ◽  
Author(s):  
Richard J. Meinersmann ◽  
Robert W. Phillips ◽  
Martin Wiedmann ◽  
Mark E. Berrang
Keyword(s):  
Listeria Monocytogenes ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Food Processing ◽  
Genomic Sequence ◽  
Processing Plant ◽  
Serotype 1 ◽  
History Of ◽  
Serotype 4B ◽  
Food Processing Plant

ABSTRACT In an attempt to develop a method to discriminate among isolates of Listeria monocytogenes, the sequences of all of the annotated genes from the fully sequenced strain L. monocytogenes EGD-e (serotype 1/2a) were compared by BLASTn to a file of the unfinished genomic sequence of L. monocytogenes ATCC 19115 (serotype 4b). Approximately 7% of the matching genes demonstrated 90% or lower identity between the two strains, and the lowest observed identity was 80%. Nine genes (hisJ, cbiE, truB, ribC, comEA, purM, aroE, hisC, and addB) in the 80 to 90% identity group and two genes (gyrB and rnhB) with approximately 97% identity were selected for multilocus sequence analysis in two sets of L. monocytogenes isolates (a 15-strain diversity set and a set of 19 isolates from a single food-processing plant). Based on concatenated sequences, a total of 33 allotypes were differentiated among the 34 isolates tested. Population genetics analyses revealed three lineages of L. monocytogenes that differed in their history of apparent recombination. Lineage I appeared to be completely clonal, whereas representatives of the other lineages demonstrated evidence of horizontal gene transfer and recombination. Although most of the gene sequences for lineage II strains were distinct from those of lineage I, a few strains with the majority of genes characteristic of lineage II had some that were characteristic of lineage I. Genes from lineage III organisms were mostly similar to lineage I genes, with instances of genes appearing to be mosaics with lineage II genes. Even though lineage I and lineage II generally demonstrated very distinct sequences, the sequences for the 11 selected genes demonstrated little discriminatory power within each lineage. In the L. monocytogenes isolate set obtained from one food-processing plant, lineage I and lineage II were found to be almost equally prevalent. While it appears that different lineages of L. monocytogenes can share habitats, they appear to differ in their histories of horizontal gene transfer.

scholarly journals Genome Sequencing Identifies Two Nearly Unchanged Strains of Persistent Listeria monocytogenes Isolated at Two Different Fish Processing Plants Sampled 6 Years Apart

2013 ◽  
Vol 79 (9) ◽  
pp. 2944-2951 ◽  
Author(s):  
Anne Holch ◽  
Kristen Webb ◽  
Oksana Lukjancenko ◽  
David Ussery ◽  
Benjamin M. Rosenthal ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Random Amplified Polymorphic Dna ◽  
The United States ◽  
Genome Comparison ◽  
Physiological Factors ◽  
Content Type ◽  
Human Pathogenic Bacterium ◽  
A Genome ◽  
Genome Analyses

ABSTRACTListeria monocytogenesis a food-borne human-pathogenic bacterium that can cause infections with a high mortality rate. It has a remarkable ability to persist in food processing facilities. Here we report the genome sequences for twoL. monocytogenesstrains (N53-1 and La111) that were isolated 6 years apart from two different Danish fish processers. Both strains are of serotype 1/2a and belong to a highly persistent DNA subtype (random amplified polymorphic DNA [RAPD] type 9). We demonstrate usingin silicoanalyses that both strains belong to the multilocus sequence typing (MLST) type ST121 that has been isolated as a persistent subtype in several European countries. The purpose of this study was to use genome analyses to identify genes or proteins that could contribute to persistence. In a genome comparison, the two persistent strains were extremely similar and collectively differed from the reference lineage II strain, EGD-e. Also, they differed markedly from a lineage I strain (F2365). On the proteome level, the two strains were almost identical, with a predicted protein homology of 99.94%, differing at only 2 proteins. No single-nucleotide polymorphism (SNP) differences were seen between the two strains; in contrast, N53-1 and La111 differed from the EGD-e reference strain by 3,942 and 3,471 SNPs, respectively. We included a persistentL. monocytogenesstrain from the United States (F6854) in our comparisons. Compared to nonpersistent strains, all three persistent strains were distinguished by two genome deletions: one, of 2,472 bp, typically contains the gene forinlF, and the other, of 3,017 bp, includes three genes potentially related to bacteriocin production and transport (lmo2774,lmo2775, and the 3′-terminal part oflmo2776). Further studies of highly persistent strains are required to determine if the absence of these genes promotes persistence. While the genome comparison did not point to a clear physiological explanation of the persistent phenotype, the remarkable similarity between the two strains indicates that subtypes with specific traits are selected for in the food processing environment and that particular genetic and physiological factors are responsible for the persistent phenotype.

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