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.

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 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.

scholarly journals Tolerance of Listeria monocytogenes to Quaternary Ammonium Sanitizers Is Mediated by a Novel Efflux Pump Encoded by emrE

2015 ◽  
Vol 82 (3) ◽  
pp. 939-953 ◽  
Author(s):  
Jovana Kovacevic ◽  
Jennifer Ziegler ◽  
Ewa Wałecka-Zacharska ◽  
Aleisha Reimer ◽  
David D. Kitts ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Food Processing ◽  
Genomic Island ◽  
Efflux Pump ◽  
Cell Adherence ◽  
Outbreak Strain ◽  
Content Type ◽  
Increased Susceptibility

ABSTRACTA novel genomic island (LGI1) was discovered inListeria monocytogenesisolates responsible for the deadliest listeriosis outbreak in Canada, in 2008. To investigate the functional role of LGI1, the outbreak strain 08-5578 was exposed to food chain-relevant stresses, and the expression of 16 LGI1 genes was measured. LGI1 genes with putative efflux (L. monocytogenesemrE[emrELm]), regulatory (lmo1851), and adhesion (sel1) functions were deleted, and the mutants were exposed to acid (HCl), cold (4°C), salt (10 to 20% NaCl), and quaternary ammonium-based sanitizers (QACs). Deletion oflmo1851had no effect on theL. monocytogenesstress response, and deletion ofsel1did not influence Caco-2 and HeLa cell adherence/invasion, whereas deletion ofemrEresulted in increased susceptibility to QACs (P< 0.05) but had no effect on the MICs of gentamicin, chloramphenicol, ciprofloxacin, erythromycin, tetracycline, acriflavine, and triclosan. In the presence of the QAC benzalkonium chloride (BAC; 5 μg/ml), 14/16 LGI1 genes were induced, andlmo1861(putative repressor gene) was constitutively expressed at 4°C, 37°C, and 52°C and in the presence of UV exposure (0 to 30 min). Following 1 h of exposure to BAC (10 μg/ml), upregulation ofemrE(49.6-fold),lmo1851(2.3-fold),lmo1861(82.4-fold), andsigB(4.1-fold) occurred. Reserpine visibly suppressed the growth of the ΔemrELmstrain, indicating that QAC tolerance is due at least partially to efflux activity. These data suggest that a minimal function of LGI1 is to increase the tolerance ofL. monocytogenesto QACs viaemrELm. Since QACs are commonly used in the food industry, there is a concern thatL. monocytogenesstrains possessingemrEwill have an increased ability to survive this stress and thus to persist in food processing environments.

scholarly journals comKProphage Junction Fragments as Markers for Listeria monocytogenes Genotypes Unique to Individual Meat and Poultry Processing Plants and a Model for Rapid Niche-Specific Adaptation, Biofilm Formation, and Persistence

2011 ◽  
Vol 77 (10) ◽  
pp. 3279-3292 ◽  
Author(s):  
Bindhu Verghese ◽  
Mei Lok ◽  
Jia Wen ◽  
Valentina Alessandria ◽  
Yi Chen ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Biofilm Formation ◽  
Content Type ◽  
Niche Adaptation ◽  
Processing Plants ◽  
Poultry Processing ◽  
Conditioning Film ◽  
Conditioning Films ◽  
Different Strains

ABSTRACTDifferent strains ofListeria monocytogenesare well known to persist in individual food processing plants and to contaminate foods for many years; however, the specific genotypic and phenotypic mechanisms responsible for persistence of these unique strains remain largely unknown. Based on sequences incomKprophage junction fragments, different strains of epidemic clones (ECs), which included ECII, ECIII, and ECV, were identified and shown to be specific to individual meat and poultry processing plants. ThecomKprophage-containing strains showed significantly higher cell densities after incubation at 30°C for 48 h on meat and poultry food-conditioning films than did strains lacking thecomKprophage (P< 0.05). Overall, the type of strain, the type of conditioning film, and the interaction between the two were all highly significant (P< 0.001). Recombination analysis indicated that thecomKprophage junction fragments in these strains had evolved due to extensive recombination. Based on the results of the present study, we propose a novel model in which the concept of defectivecomKprophage was replaced with the rapid adaptation island (RAI). Genes within the RAI were recharacterized as “adaptons,” as these genes may allowL. monocytogenesto rapidly adapt to different food processing facilities and foods. If confirmed, the model presented would help explainListeria's rapid niche adaptation, biofilm formation, persistence, and subsequent transmission to foods. Also,comKprophage junction fragment sequences may permit accurate tracking of persistent strains back to and within individual food processing operations and thus allow the design of more effective intervention strategies to reduce contamination and enhance food safety.

scholarly journals The Connection between Persistent, Disinfectant-Resistant Listeria monocytogenes Strains from Two Geographically Separate Iberian Pork Processing Plants: Evidence from Comparative Genome Analysis

2015 ◽  
Vol 82 (1) ◽  
pp. 308-317 ◽  
Author(s):  
Sagrario Ortiz ◽  
Victoria López-Alonso ◽  
Pablo Rodríguez ◽  
Joaquín V. Martínez-Suárez
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Pfge Type ◽  
Processing Plant ◽  
Content Type ◽  
Pork Products ◽  
Processing Plants ◽  
Pork Product ◽  
Ammonium Compounds ◽  
Insight Into

ABSTRACTThe aim of this study was to investigate the basis of the putative persistence ofListeria monocytogenesin a new industrial facility dedicated to the processing of ready-to-eat (RTE) Iberian pork products. Quaternary ammonium compounds, which included benzalkonium chloride (BAC), were repeatedly used as surface disinfectants in the processing plant. Clean and disinfected surfaces were sampled to evaluate if resistance to disinfectants was associated with persistence. Of the 14 isolates obtained from product contact and non-product contact surfaces, only five different pulsed-field gel electrophoresis (PFGE) types were identified during the 27-month study period. Two of these PFGE types (S1 and S10-1) were previously identified to be persistent and BAC-resistant (BACr) strains in a geographically separate slaughterhouse belonging to the same company. The remaining three PFGE types, which were first identified in this study, were also BACr. Whole-genome sequencing andin silicomultilocus sequence typing (MLST) analysis of five BACrisolates of the different PFGE types identified in this study showed that the isolate of the S1 PFGE type belonged to MLST sequence type 31 (ST31), a low-virulence type characterized by mutations in theinlAandprfAgenes. The isolates of the remaining four PFGE types were found to belong to MLST ST121, a persistent type that has been isolated in several countries. The ST121 strains contained the BAC resistance transposon Tn6188. The disinfection-resistantL. monocytogenespopulation in this RTE pork product plant comprised two distinct genotypes with different multidrug resistance phenotypes. This work offers insight into theL. monocytogenessubtypes associated with persistence in food processing environments.

scholarly journals Biofilm Formation by Listeria monocytogenes 15G01, a Persistent Isolate from a Seafood-Processing Plant, Is Influenced by Inactivation of Multiple Genes Belonging to Different Functional Groups

2021 ◽  
Vol 87 (10) ◽  
Author(s):  
Jessika Nowak ◽  
Sandra B. Visnovsky ◽  
Andrew R. Pitman ◽  
Cristina D. Cruz ◽  
Jon Palmer ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Biofilm Formation ◽  
Processing Plant ◽  
Wild Type ◽  
Content Type ◽  
Multiple Genes ◽  
Processing Plants ◽  
Biofilm Structure ◽  
Seafood Processing

ABSTRACT Listeria monocytogenes is a ubiquitous foodborne pathogen that results in a high rate of mortality in sensitive and immunocompromised people. Contamination of food with L. monocytogenes is thought to occur during food processing, most often as a result of the pathogen producing a biofilm that persists in the environment and acting as the source for subsequent dispersal of cells onto food. A survey of seafood-processing plants in New Zealand identified the persistent strain 15G01, which has a high capacity to form biofilms. In this study, a transposon library of L. monocytogenes 15G01 was screened for mutants with altered biofilm formation, assessed by a crystal violet assay, to identify genes involved in biofilm formation. This screen identified 36 transposants that showed a significant change in biofilm formation compared to the wild type. The insertion sites were in 27 genes, 20 of which led to decreased biofilm formation and seven to an increase. Two insertions were in intergenic regions. Annotation of the genes suggested that they are involved in diverse cellular processes, including stress response, autolysis, transporter systems, and cell wall/membrane synthesis. Analysis of the biofilms produced by the transposants using scanning electron microscopy and fluorescence microscopy showed notable differences in the structure of the biofilms compared to the wild type. In particular, inactivation of uvrB and mltD produced coccoid-shaped cells and elongated cells in long chains, respectively, and the mgtB mutant produced a unique biofilm with a sandwich structure which was reversed to the wild-type level upon magnesium addition. The mltD transposant was successfully complemented with the wild-type gene, whereas the phenotypes were not or only partially restored for the remaining mutants. IMPORTANCE The major source of contamination of food with Listeria monocytogenes is thought to be due to biofilm formation and/or persistence in food-processing plants. By establishing as a biofilm, L. monocytogenes cells become harder to eradicate due to their increased resistance to environmental threats. Understanding the genes involved in biofilm formation and their influence on biofilm structure will help identify new ways to eliminate harmful biofilms in food processing environments. To date, multiple genes have been identified as being involved in biofilm formation by L. monocytogenes; however, the exact mechanism remains unclear. This study identified four genes associated with biofilm formation by a persistent strain. Extensive microscopic analysis illustrated the effect of the disruption of mgtB, clsA, uvrB, and mltD and the influence of magnesium on the biofilm structure. The results strongly suggest an involvement in biofilm formation for the four genes and provide a basis for further studies to analyze gene regulation to assess the specific role of these biofilm-associated genes.

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.

scholarly journals Comparative Analysis of Genetic Determinants Encoding Cadmium, Arsenic, and Benzalkonium Chloride Resistance in Listeria monocytogenes of Human, Food, and Environmental Origin

2021 ◽  
Vol 11 ◽  
Author(s):  
Tereza Gelbicova ◽  
Martina Florianova ◽  
Lucie Hluchanova ◽  
Alžběta Kalova ◽  
Kristýna Korena ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Benzalkonium Chloride ◽  
Extensive Study ◽  
Whole Genome Sequencing Data ◽  
Production Environment ◽  
Sequencing Data ◽  
Genetic Determinants ◽  
Cadmium Resistance ◽  
Chloride Resistance ◽  
Genes Encoding

Environmental adaptation of Listeria monocytogenes is a complex process involving various mechanisms that can contribute to their survival in the environment, further spreading throughout the food chain and the development of listeriosis. The aim of this study was to analyze whole-genome sequencing data in a set of 270 strains of L. monocytogenes derived from human listeriosis cases and food and environmental sources in order to compare the prevalence and type of genetic determinants encoding cadmium, arsenic, and benzalkonium chloride resistance. Most of the detected genes of cadmium (27.8%), arsenic (15.6%), and benzalkonium chloride (7.0%) resistance were located on mobile genetic elements, even in phylogenetically distant lineages I and II, which indicates the possibility of their horizontal spread. Although no differences were found in the prevalence of these genes between human and food strains, they have been detected sporadically in strains from the environment. Regarding cadmium resistance genes, cadA1C1_Tn5422 predominated, especially in clonal complexes (CCs) 121, 8, and 3 strains. At the same time, qacH_Tn6188-encoding benzalkonium chloride resistance was most frequently detected in the genome of CC121 strains. Genes encoding arsenic resistance were detected mainly in strains CC2 (located on the chromosomal island LGI2) and CC9 (carried on Tn554). The results indicated a relationship between the spread of genes encoding resistance to cadmium, arsenic, and benzalkonium chloride in certain serotypes and CCs and showed the need for a more extensive study of L. monocytogenes strains to better understand their ability to adapt to the food production environment.

scholarly journals Persistent Listeria monocytogenes Isolates from a Poultry-Processing Facility Form More Biofilm but Do Not Have a Greater Resistance to Disinfectants than Sporadic Strains

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 250 ◽  
Author(s):  
Daniel Rodríguez-Campos ◽  
Cristina Rodríguez-Melcón ◽  
Carlos Alonso-Calleja ◽  
Rosa Capita
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Biofilm Formation ◽  
Benzalkonium Chloride ◽  
Bacterial Persistence ◽  
Crystal Violet Assay ◽  
Processing Facility ◽  
Poultry Processing ◽  
Sessile Cells ◽  
Selection Of

Some strains of Listeria monocytogenes can persist in food-processing environments, increasing the likelihood of the contamination of foodstuffs. To identify traits that contribute to bacterial persistence, a selection of persistent and sporadic L. monocytogenes isolates from a poultry-processing facility was investigated for biofilm-forming ability (crystal violet assay). The susceptibility of sessile cells to treatments (five minutes) with sodium hypochlorite having 10% active chlorine (SHY: 10,000 ppm, 25,000 ppm, and 50,000 ppm) and benzalkonium chloride (BZK: 2500 ppm, 10,000 ppm, and 25,000 ppm) was also studied. All isolates exhibited biofilm formation on polystyrene. Persistent strains showed larger (p < 0.001) biofilm formation (OD580 = 0.301 ± 0.097) than sporadic strains (OD580 = 0.188 ± 0.082). A greater susceptibility to disinfectants was observed for biofilms of persistent strains than for those of sporadic strains. The application of SHY reduced biofilms only for persistent strains. BZK increased OD580 in persistent strains (2500 ppm) and in sporadic strains (all concentrations). These results indicate that the use of BZK at the concentrations tested could represent a public health risk. Findings in this work suggest a link between persistence and biofilm formation, but do not support a relationship between persistence and the resistance of sessile cells to disinfectants.

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