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Kumari K, Sharma PK, Singh RP. Unravelling the transcriptome response of Enterobacter sp. S-33 under varying temperature. Arch Microbiol 2024; 206:81. [PMID: 38294553 DOI: 10.1007/s00203-023-03792-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 11/22/2023] [Accepted: 12/11/2023] [Indexed: 02/01/2024]
Abstract
Enterobacter genus includes the bacteria occupying every aspect of environment, however, their adaptability at varying temperature is not clear. In the present study, we analyzed the transcriptome response of Enterobacter sp. S-33 and their functional genes under various temperatures (30-45 ℃) that were expressed and accumulated in cells under temperature-stress. During a temperature shift from 37 to 45 ℃, 165 genes showed differential expression including 112 up-regulated and 53 down-regulated. In particular, heat-shock genes such as CspA, 16 kDa heat shock protein A/B and transcriptional regulators such as LysR, TetR, and LuxR were differentially expressed, indicating the role of complex molecular mechanism of Enterobacter adapting to temperature stress. Similarly, genes associated to signal transduction, ABC transporters, iron homeostasis, and quorum sensing were also induced. The Gene ontology enrichment analysis of differentially expressed genes (DEGs) were categorized into "transmembrane transport", "tRNA binding", "hydrogen sulfide biosynthetic process" and "sulfate assimilation" terms. In addition, Kyoto Encyclopedia of Genes and Genomes pathways showed that ABC transporter as well as quorum sensing pathways were significantly enriched. Overall, current study has contributed to explore the adaptive molecular mechanisms of Enterobacter spp. upon temperature change, which further opens new avenues for future in-depth functional studies.
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Affiliation(s)
- Kiran Kumari
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India
| | - Parva Kumar Sharma
- Department of Plant Sciences and Landscape Architecture, University of Maryland, College Park, MD, 20742, USA
| | - Rajnish Prakash Singh
- Department of Biotechnology, Jaypee Institute of Information Technology, Noida, India.
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Chandran S, Baker CA, Hamilton AN, Dhulappanavar GR, Jones SL, Gibson KE. Aqueous Ozone Efficacy for Inactivation of Foodborne Pathogens on Vegetables Used in Raw Meat-Based Diets for Companion Animals. J Food Prot 2023; 86:100175. [PMID: 37802235 DOI: 10.1016/j.jfp.2023.100175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/19/2023] [Accepted: 09/29/2023] [Indexed: 10/08/2023]
Abstract
The present study evaluates the efficacy of a batch wash ozone sanitation system (BWOSS) and spray wash ozone sanitation system (SWOSS) against Listeria monocytogenes (two strains) and Salmonella enterica subsp. enterica (three serovars) inoculated on the surface of carrots, sweet potatoes, and butternut squash, commonly used in raw meat-based diets (RMBDs) marketed for companion animals such as dogs and cats. Produce either remained at room temperature for 2 h or were frozen at -20°C and then tempered overnight at 4°C to mimic the preprocessing steps of a raw pet food processing operation ('freeze-temper') prior to ozone treatment. Two ozone concentrations (0 and 5 ppm) were applied for either 20 s or 60 s for BWOSS and 20 s for SWOSS. Based on an ANOVA, BWOSS data showed no significant difference (P > 0.05) in microbial reduction between 0 and 5 ppm ozone concentration across all treatment durations for each produce type. BWOSS resulted in mean microbial reductions of up to 1.56 log CFU/mL depending on the treatment time and produce type. SWOSS data were analyzed using a generalized linear model with Quasipoisson errors. Freeze-tempered produce treated with SWOSS had a higher bacterial log reduction at 5 ppm ozone compared to 0 ppm ozone (P = 0.0013) whereas room temperature produce treated with SWOSS did not show any significant difference in microbial reduction between ozone concentrations. The potential to mitigate microbial cross-contamination was also investigated during SWOSS treatment. The results indicate that 5 ppm ozone decreased pathogens in the rinsate and proximal surfaces by 0.63-1.66 log CFU/mL greater than no ozone depending on the pathogen and sample. Overall, data from this study indicate that SWOSS would be more effective compared to BWOSS in reducing the microbial load present on the surface of root tubers and squash subjected to freezing and thawing and has the potential to mitigate cross-contamination within RMDB manufacturing environments.
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Affiliation(s)
- Sahaana Chandran
- Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72704, USA
| | - Christopher A Baker
- Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72704, USA
| | - Allyson N Hamilton
- Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72704, USA
| | - Gayatri R Dhulappanavar
- Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72704, USA
| | - Sarah L Jones
- Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72704, USA
| | - Kristen E Gibson
- Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72704, USA.
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Wiktorczyk-Kapischke N, Skowron K, Wałecka-Zacharska E, Grudlewska-Buda K, Wnuk K, Buszko K, Gospodarek-Komkowska E. Assessment of the influence of selected stress factors on the growth and survival of Listeria monocytogenes. BMC Microbiol 2023; 23:27. [PMID: 36690941 PMCID: PMC9872351 DOI: 10.1186/s12866-023-02766-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 01/10/2023] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Listeria monocytogenes are Gram-positive rods, which are the etiological factor of listeriosis. L. monocytogenes quickly adapts to changing environmental conditions. Since the main source of rods is food, its elimination from the production line is a priority. The study aimed to evaluate the influence of selected stress factors on the growth and survival of L. monocytogenes strains isolated from food products and clinical material. RESULTS We distinguished fifty genetically different strains of L. monocytogenes (PFGE method). Sixty-two percent of the tested strains represented 1/2a-3a serogroup. Sixty percent of the rods possessed ten examined virulence genes (fbpA, plcA, hlyA, plcB, inlB, actA, iap, inlA, mpl, prfA). Listeria Pathogenicity Island 1 (LIPI-1) was demonstrated among 38 (76.0%) strains. Majority (92.0%) of strains (46) were sensitive to all examined antibiotics. The most effective concentration of bacteriophage (inhibiting the growth of 22 strains; 44.0%) was 5 × 108 PFU. In turn, the concentration of 8% of NaCl was enough to inhibit the growth of 31 strains (62.0%). The clinical strain tolerated the broadest pH range (3 to 10). Five strains survived the 60-min exposure to 70˚C, whereas all were alive at each time stage of the cold stress experiment. During the stress of cyclic freezing-defrosting, an increase in the number of bacteria was shown after the first cycle, and a decrease was only observed after cycle 3. The least sensitive to low nutrients content were strains isolated from frozen food. The high BHI concentration promoted the growth of all groups. CONCLUSIONS Data on survival in stress conditions can form the basis for one of the hypotheses explaining the formation of persistent strains. Such studies are also helpful for planning appropriate hygiene strategies within the food industry.
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Affiliation(s)
- Natalia Wiktorczyk-Kapischke
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Krzysztof Skowron
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland.
| | - Ewa Wałecka-Zacharska
- Department of Food Hygiene and Consumer Health, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Katarzyna Grudlewska-Buda
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Kacper Wnuk
- Department of Theoretical Foundations of Biomedical Sciences and Medical Computer Science, Ludwik Rydygier Collegium Medium in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Katarzyna Buszko
- Department of Theoretical Foundations of Biomedical Sciences and Medical Computer Science, Ludwik Rydygier Collegium Medium in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Eugenia Gospodarek-Komkowska
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
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Zhao Y, Kang X, Zhou W, Lee J, Wang S, Cui Z, Zhang H, Mo H, Hu L. Ferrous sulfate efficiently kills Vibrio parahaemolyticus and protects salmon sashimi from its contamination. Int J Food Microbiol 2022; 382:109929. [PMID: 36116390 DOI: 10.1016/j.ijfoodmicro.2022.109929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 08/30/2022] [Accepted: 09/09/2022] [Indexed: 10/14/2022]
Abstract
The primary seafood-borne pathogen Vibrio parahaemolyticus seriously threats the health of consumers preferring raw-fish products, becoming a global concern in food safety. In the present study, we found ferrous sulfate (FeSO4), a nutritional iron supplement, could efficiently induce the death of V. parahaemolyticus. Further, the bactericidal mechanisms of FeSO4 were explored. With a fluorescent probe of Fe2+, a significant influx of Fe2+ was determined in V. parahaemolyticus exposed to FeSO4, and the addition of an intracellular Fe2+ chelator was able to block the cell death. This suggested that cell death in V. parahaemolyticus induced by FeSO4 was dependent on the influx of Fe2+. It was intriguing that we did not observe the eruption of reactive oxygen species (ROS) and lipid hydroperoxides by Fe2+, but the application of liproxstatin-1 (a ferroptosis inhibitor) significantly modified the occurrence of cell death in V. parahaemolyticus. These results suggested FeSO4-induced cell death in V. parahaemolyticus be a ferroptosis differing from that in mammalian cells. Through transcriptome analysis, it was discovered that the exposure of FeSO4 disturbed considerable amounts of gene expression in V. parahaemolyticus including those involved in protein metabolism, amide biosynthesis, two-component system, amino acid degradation, carbon metabolism, citrate cycle, pyruvate metabolism, oxidative phosphorylation, and so on. These data suggested that FeSO4 was a pleiotropic antimicrobial agent against V. parahaemolyticus. Notably, FeSO4 was able to eliminate V. parahaemolyticus in salmon sashimi as well, without affecting the color, texture, shearing force, and sensory characteristics of salmon sashimi. Taken together, our results deciphered a unique ferroptosis in V. parahaemolyticus by FeSO4, and highlighted its potential in raw-fish products to control V. parahaemolyticus.
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Affiliation(s)
- Yanyan Zhao
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China; Key Laboratory of Aquatic Products Processing and Safety Control, Xinxiang 453003, China
| | - Xiaofeng Kang
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China; Key Laboratory of Aquatic Products Processing and Safety Control, Xinxiang 453003, China
| | - Wei Zhou
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China; Key Laboratory of Aquatic Products Processing and Safety Control, Xinxiang 453003, China
| | - Jintae Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Shuyan Wang
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China; Key Laboratory of Aquatic Products Processing and Safety Control, Xinxiang 453003, China
| | - Zhenkun Cui
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China; Key Laboratory of Aquatic Products Processing and Safety Control, Xinxiang 453003, China
| | - Hao Zhang
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China; Key Laboratory of Aquatic Products Processing and Safety Control, Xinxiang 453003, China
| | - Haizhen Mo
- Department of Food and Bioengineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
| | - Liangbin Hu
- Department of Food and Bioengineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
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Ability of Two Strains of Lactic Acid Bacteria To Inhibit Listeria monocytogenes by Spot Inoculation and in an Environmental Microbiome Context. Microbiol Spectr 2022; 10:e0101822. [PMID: 35852346 PMCID: PMC9431016 DOI: 10.1128/spectrum.01018-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We evaluated the ability of two strains of lactic acid bacteria (LAB) to inhibit L. monocytogenes using spot inoculation and environmental microbiome attached-biomass assays. LAB strains (PS01155 and PS01156) were tested for antilisterial activity toward 22 phylogenetically distinct L. monocytogenes strains isolated from three fruit packing environments (F1, F2, and F3). LAB strains were tested by spot inoculation onto L. monocytogenes lawns (108 and 107 CFU/mL) and incubated at 15, 20, 25, or 30°C for 3 days. The same LAB strains were also cocultured at 15°C for 3, 5, and 15 days in polypropylene conical tubes with L. monocytogenes and environmental microbiome suspensions collected from F1, F2, and F3. In the spot inoculation assay, PS01156 was significantly more inhibitory toward less concentrated L. monocytogenes lawns than more concentrated lawns at all the tested temperatures, while PS01155 was significantly more inhibitory toward less concentrated lawns only at 15 and 25°C. Furthermore, inhibition of L. monocytogenes by PS01156 was significantly greater at 15°C than higher temperatures, whereas the temperature did not have an effect on the inhibitory activity of PS01155. In the assay using attached environmental microbiome biomass, L. monocytogenes concentration was significantly reduced by PS01156, but not PS01155, when cocultured with microbiomes from F1 and F3 and incubated for 3 days at 15°C. Attached biomass microbiota composition was significantly affected by incubation time but not by LAB strain. This study demonstrates that LAB strains that may exhibit inhibitory properties toward L. monocytogenes in a spot inoculation assay may not maintain antilisterial activity within a complex microbiome. IMPORTANCEListeria monocytogenes has previously been associated with outbreaks of foodborne illness linked to consumption of fresh produce. In addition to conventional cleaning and sanitizing, lactic acid bacteria (LAB) have been studied for biocontrol of L. monocytogenes in food processing environments that are challenging to clean and sanitize. We evaluated whether two specific LAB strains, PS01155 and PS01156, can inhibit the growth of L. monocytogenes strains in a spot inoculation and in an attached-biomass assay, in which they were cocultured with environmental microbiomes collected from tree fruit packing facilities. LAB strains PS01155 and PS01156 inhibited L. monocytogenes in a spot inoculation assay, but the antilisterial activity was lower or not detected when they were grown with environmental microbiota. These results highlight the importance of conducting biocontrol challenge tests in the context of the complex environmental microbiomes present in food processing facilities to assess their potential for application in the food industry.
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Phenotypic characterization and analysis of complete genomes of two distinct strains of the proposed species "L. swaminathanii". Sci Rep 2022; 12:9137. [PMID: 35650389 PMCID: PMC9159981 DOI: 10.1038/s41598-022-13119-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 04/27/2022] [Indexed: 11/29/2022] Open
Abstract
Recently, a new Listeria species, “Listeria swaminathanii”, was proposed. Here, we phenotypically and genotypically characterize two additional strains that were previously obtained from soil samples and compare the results to the type strain. Complete genomes for both strains were assembled from hybrid Illumina and Nanopore sequencing reads and annotated. Further genomic analysis including average nucleotide identity (ANI) and detection of mobile genetic elements and genes of interest (e.g., virulence-associated) were conducted. The strains showed 98.7–98.8% ANI with the type strain. The UTK C1-0015 genome contained a partial monocin locus and a plasmid, while the UTK C1-0024 genome contained a full monocin locus and a prophage. Phenotypic characterization consistent with those performed on the proposed type strain was conducted to assess consistency of phenotypes across a greater diversity of the proposed species (n = 3 instead of n = 1). Only a few findings were notably different from those of the type strain, such as catalase activity, glycerol metabolism, starch metabolism, and growth at 41 °C. This study further expands our understanding of this newly proposed sensu stricto Listeria species.
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Behavior of Native Food Isolates of Listeria monocytogenes and Listeria innocua under the Influence of Selected Cultural Attributes and Heat and Cold Treatments. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2021. [DOI: 10.22207/jpam.15.4.44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The present investigation assesses the influence of cultural attributes and heat and cold treatments on the behaviour of native toxigenic L. monocytogenes CFR 1302 and non-toxigenic L. innocua CFR 1304 in selected medium. The growth responses of L. monocytogenes and L. innocua under the influencing factors of storage temperature (10-40°C), pH level (5.5-7.5), and storage period (6-48 h) in brain heart infusion and nutrient broths revealed closeness between observed and predicted populations. Response surface plots were generated for the growth behavior of the two test cultures as a function of pH level. The toxigenic L. monocytogenes CFR 1302 could reach a higher viable population. The effect of heat treatment on Listeria spp. in selected five heating menstra showed the lowest D-value of 3.7 min at 60°C for L. innocua CFR 1304 in Milli-Q water to the highest of 8.4 min at 56°C for L. monocytogenes CFR 1302 in skim milk. The average z-value across the heating menstra for L. monocytogenes was 27.3°C as against that of 22°C for L. innocua. In the case of cold treatment, storage of 4 and 8°C resulted in appreciable increase in counts of L. monocytogenes CFR 1302 from the initial inoculum introduced in selected media. At -20°C, there was a slight decrease in the viable population. The research data helps to predict the viable populations of L. monocytogenes as a part of risk assessment in the food chain. This is of significance in providing safe and healthy food to human population.
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Wong CH, Mak IEK, Li D. Bilayer edible coating with stabilized Lactobacillus plantarum 299v improved the shelf life and safety quality of fresh-cut apple slices. Food Packag Shelf Life 2021. [DOI: 10.1016/j.fpsl.2021.100746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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9
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Rhizobacteria Impact Colonization of Listeria monocytogenes on Arabidopsis thaliana Roots. Appl Environ Microbiol 2021; 87:e0141121. [PMID: 34550783 PMCID: PMC8579980 DOI: 10.1128/aem.01411-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In spite of its relevance as a foodborne pathogen, we have limited knowledge about Listeria monocytogenes in the environment. L. monocytogenes outbreaks have been linked to fruits and vegetables; thus, a better understanding of the factors influencing its ability to colonize plants is important. We tested how environmental factors and other soil- and plant-associated bacteria influenced L. monocytogenes' ability to colonize plant roots using Arabidopsis thaliana seedlings in a hydroponic growth system. We determined that the successful root colonization of L. monocytogenes 10403S was modestly but significantly enhanced by the bacterium being pregrown at higher temperatures, and this effect was independent of the biofilm and virulence regulator PrfA. We tested 14 rhizosphere-derived bacteria for their impact on L. monocytogenes 10403S, identifying one that enhanced and 10 that inhibited the association of 10403S with plant roots. We also characterized the outcomes of these interactions under both coinoculation and invasion conditions. We characterized the physical requirements of five of these rhizobacteria to impact the association of L. monocytogenes 10403S with roots, visualizing one of these interactions by microscopy. Furthermore, we determined that two rhizobacteria (one an inhibitor, the other an enhancer of 10403S root association) were able to similarly impact 10 different L. monocytogenes strains, indicating that the effects of these rhizobacteria on L. monocytogenes are not strain specific. Taken together, our results advance our understanding of the parameters that affect L. monocytogenes plant root colonization, knowledge that may enable us to deter its association with and, thus, downstream contamination of, food crops. IMPORTANCE Listeria monocytogenes is ubiquitous in the environment, being found in or on soil, water, plants, and wildlife. However, little is known about the requirements for L. monocytogenes' existence in these settings. Recent L. monocytogenes outbreaks have been associated with contaminated produce; thus, we used a plant colonization model to investigate factors that alter L. monocytogenes' ability to colonize plant roots. We show that L. monocytogenes colonization of roots was enhanced when grown at higher temperatures prior to inoculation but did not require a known regulator of virulence and biofilm formation. Additionally, we identified several rhizobacteria that altered the ability of 11 different strains of L. monocytogenes to colonize plant roots. Understanding the factors that impact L. monocytogenes physiology and growth will be crucial for finding mechanisms (whether chemical or microbial) that enable its removal from plant surfaces to reduce L. monocytogenes contamination of produce and eliminate foodborne illness.
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Hobbs L, Allen L, Bias M, Johnson S, DeRespiris H, Diallo C, Bui L, Sun Y. The Opposing Role of Propionate in Modulating Listeria monocytogenes Intracellular Infections. Front Microbiol 2021; 12:721801. [PMID: 34539613 PMCID: PMC8442606 DOI: 10.3389/fmicb.2021.721801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/31/2021] [Indexed: 11/13/2022] Open
Abstract
Listeria monocytogenes is a Gram-positive, intracellular pathogen responsible for the highly fatal foodborne illness listeriosis. Establishing intracellular infections requires the coordinated expressions of a variety of virulence factors, such as the pore-forming toxin listeriolysin O (LLO), in response to various intra- and extracellular signals. For example, we previously reported that L. monocytogenes differentially modulated LLO production in response to exogenous propionate, a short chain fatty acid either used in salt form as a human food ingredient or produced endogenously by gut microbial fermentation. Therefore, propionate is likely a continuously present signal throughout the L. monocytogenes transmission and infection process. However, little is known about the role of propionate in modulating L. monocytogenes-host interactions. Here we investigated the impact of propionate treatment on L. monocytogenes intracellular infections using cell culture infection models. Propionate treatment was performed separately on L. monocytogenes or host cells before or during infections to better distinguish pathogen-versus-host responses to propionate. Intracellular CFU in RAW264.7 macrophages and plaque diameters in L-fibroblasts were measured as proxy for intracellular infection outcomes. Nitrite levels and cellular morphology were also measured to assess host responses to propionate. We found that propionate pretreatment of anaerobic, but not aerobic, L. monocytogenes significantly enhanced subsequent intracellular infections in both cell types and nitrite production by infected macrophages. Propionate treatment of uninfected macrophages significantly altered cell morphology, seen by longer cells and greater migration, and reduced nitrite concentration in activated macrophages. Treatment of macrophages with propionate prior to or during infections significantly inhibited intracellular growth of L. monocytogenes, including those pre-treated with propionate. These results showcased an opposing effect of propionate on L. monocytogenes intracellular infections and strongly support propionate as an important signaling molecule for both the pathogen and the host cell that can potentially alter the outcome of L. monocytogenes-host interactions.
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Affiliation(s)
- Laura Hobbs
- Department of Biology, University of Dayton, Dayton, OH, United States
| | - Leah Allen
- Department of Biology, University of Dayton, Dayton, OH, United States
| | - Megan Bias
- Department of Biology, University of Dayton, Dayton, OH, United States
| | - Stephanie Johnson
- Department of Biology, University of Dayton, Dayton, OH, United States
| | - Hannah DeRespiris
- Department of Biology, University of Dayton, Dayton, OH, United States
| | - Chantal Diallo
- Department of Biology, University of Dayton, Dayton, OH, United States
| | - Loan Bui
- Department of Biology, University of Dayton, Dayton, OH, United States
| | - Yvonne Sun
- Department of Biology, University of Dayton, Dayton, OH, United States
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Modernization of Control of Pathogenic Micro-Organisms in the Food-Chain Requires a Durable Role for Immunoaffinity-Based Detection Methodology-A Review. Foods 2021; 10:foods10040832. [PMID: 33920486 PMCID: PMC8069916 DOI: 10.3390/foods10040832] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/28/2021] [Accepted: 04/02/2021] [Indexed: 01/03/2023] Open
Abstract
Food microbiology is deluged by a vastly growing plethora of analytical methods. This review endeavors to color the context into which methodology has to fit and underlines the importance of sampling and sample treatment. The context is that the highest risk of food contamination is through the animal and human fecal route with a majority of foodborne infections originating from sources in mass and domestic kitchens at the end of the food-chain. Containment requires easy-to-use, failsafe, single-use tests giving an overall risk score in situ. Conversely, progressive food-safety systems are relying increasingly on early assessment of batches and groups involving risk-based sampling, monitoring environment and herd/flock health status, and (historic) food-chain information. Accordingly, responsible field laboratories prefer specificity, multi-analyte, and high-throughput procedures. Under certain etiological and epidemiological circumstances, indirect antigen immunoaffinity assays outperform the diagnostic sensitivity and diagnostic specificity of e.g., nucleic acid sequence-based assays. The current bulk of testing involves therefore ante- and post-mortem probing of humoral response to several pathogens. In this review, the inclusion of immunoglobulins against additional invasive micro-organisms indicating the level of hygiene and ergo public health risks in tests is advocated. Immunomagnetic separation, immunochromatography, immunosensor, microsphere array, lab-on-a-chip/disc platforms increasingly in combination with nanotechnologies, are discussed. The heuristic development of portable and ambulant microfluidic devices is intriguing and promising. Tant pis, many new platforms seem unattainable as the industry standard. Comparability of results with those of reference methods hinders the implementation of new technologies. Whatever the scientific and technological excellence and incentives, the decision-maker determines this implementation after weighing mainly costs and business risks.
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Koutsoumanis K, Allende A, Alvarez‐Ordóñez A, Bolton D, Bover‐Cid S, Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Jacxsens L, Skjerdal T, Da Silva Felício MT, Hempen M, Messens W, Lindqvist R. Guidance on date marking and related food information: part 2 (food information). EFSA J 2021; 19:e06510. [PMID: 33897858 PMCID: PMC8061283 DOI: 10.2903/j.efsa.2021.6510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
A risk-based approach was used to develop guidance to be followed by food business operators (FBOs) when deciding on food information relating to storage conditions and/or time limits for consumption after opening a food package and thawing of frozen foods. After opening the package, contamination may occur, introducing new pathogens into the food and the intrinsic (e.g. pH and aw), extrinsic (e.g. temperature and gas atmosphere) and implicit (e.g. interactions with competing background microbiota) factors may change, affecting microbiological food safety. Setting a time limit for consumption after opening the package (secondary shelf-life) is complex in view of the many influencing factors and information gaps. A decision tree (DT) was developed to assist FBOs in deciding whether the time limit for consumption after opening, due to safety reasons, is potentially shorter than the initial 'best before' or 'use by' date of the product in its unopened package. For products where opening the package leads to a change of the type of pathogenic microorganisms present in the food and/or factors increasing their growth compared to the unopened product, a shorter time limit for consumption after opening would be appropriate. Freezing prevents the growth of pathogens, however, most pathogenic microorganisms may survive frozen storage, recover during thawing and then grow and/or produce toxins in the food, if conditions are favourable. Moreover, additional contamination may occur from hands, contact surfaces or contamination from other foods and utensils. Good practices for thawing should, from a food safety point of view, minimise growth of and contamination by pathogens between the food being thawed and other foods and/or contact surfaces, especially when removing the food from the package during thawing. Best practices for thawing foods are presented to support FBOs.
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Xie T, Pang R, Wu Q, Zhang J, Lei T, Li Y, Wang J, Ding Y, Chen M, Bai J. Cold Tolerance Regulated by the Pyruvate Metabolism in Vibrio parahaemolyticus. Front Microbiol 2019; 10:178. [PMID: 30787922 PMCID: PMC6372572 DOI: 10.3389/fmicb.2019.00178] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 01/22/2019] [Indexed: 11/13/2022] Open
Abstract
Vibrio parahaemolyticus is a common foodborne pathogen found in seafood, and represents a major threat to human health worldwide. Low-temperature storage is an important seafood processing method, but is not sufficient to completely eliminate the bacteria and avoid foodborne illness. To determine the mechanisms behind such cold tolerance, RNA-seq and iTRAQ analyses were first performed to obtain the global transcriptomic and proteomic patterns of frozen squid and clinical V. parahaemolyticus isolates under cold conditions. The integrated analysis revealed the modulation of multiple pathways such as the co-occurrence of down-regulated pyruvate metabolism and up-regulated fatty acid biosynthesis, which likely contribute to V. parahaemolyticus cold tolerance. Furthermore, we found that increasing concentrations of pyruvate can reduce the fatty acid content to influence V. parahaemolyticus growth in cold conditions. Thus, regulation of pyruvate concentration may be an effective method to control this seafood-borne pathogen.
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Affiliation(s)
- Tengfei Xie
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Rui Pang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Qingping Wu
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Juemei Zhang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Tao Lei
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Yanping Li
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Yu Ding
- Department of Food Science & Technology, Jinan University, Guangzhou, China
| | - Moutong Chen
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Jianlin Bai
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
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14
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Ochiai Y, Yamada F, Yoshikawa Y, Mochizuki M, Takano T, Hondo R, Ueda F. Sequential transition of the injury phenotype, temperature-dependent survival and transcriptional response in Listeria monocytogenes following lethal H 2 O 2 exposure. Int J Food Microbiol 2017; 259:52-58. [DOI: 10.1016/j.ijfoodmicro.2017.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 07/29/2017] [Accepted: 08/01/2017] [Indexed: 11/29/2022]
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15
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Manyi-Loh CE, Mamphweli SN, Meyer EL, Makaka G, Simon M, Okoh AI. An Overview of the Control of Bacterial Pathogens in Cattle Manure. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13090843. [PMID: 27571092 PMCID: PMC5036676 DOI: 10.3390/ijerph13090843] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 01/18/2023]
Abstract
Cattle manure harbors microbial constituents that make it a potential source of pollution in the environment and infections in humans. Knowledge of, and microbial assessment of, manure is crucial in a bid to prevent public health and environmental hazards through the development of better management practices and policies that should govern manure handling. Physical, chemical and biological methods to reduce pathogen population in manure do exist, but are faced with challenges such as cost, odor pollution, green house gas emission, etc. Consequently, anaerobic digestion of animal manure is currently one of the most widely used treatment method that can help to salvage the above-mentioned adverse effects and in addition, produces biogas that can serve as an alternative/complementary source of energy. However, this method has to be monitored closely as it could be fraught with challenges during operation, caused by the inherent characteristics of the manure. In addition, to further reduce bacterial pathogens to a significant level, anaerobic digestion can be combined with other methods such as thermal, aerobic and physical methods. In this paper, we review the bacterial composition of cattle manure as well as methods engaged in the control of pathogenic microbes present in manure and recommendations that need to be respected and implemented in order to prevent microbial contamination of the environment, animals and humans.
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Affiliation(s)
- Christy E Manyi-Loh
- Fort Hare Institute of Technology, University of Fort Hare, Alice Campus, Alice 5700, Eastern Cape Province, South Africa.
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice Campus, Alice 5700, Eastern Cape Province, South Africa.
| | - Sampson N Mamphweli
- Fort Hare Institute of Technology, University of Fort Hare, Alice Campus, Alice 5700, Eastern Cape Province, South Africa.
| | - Edson L Meyer
- Fort Hare Institute of Technology, University of Fort Hare, Alice Campus, Alice 5700, Eastern Cape Province, South Africa.
| | - Golden Makaka
- Department of Physics, University of Fort Hare, Alice Campus, Alice 5700, Eastern Cape Province, South Africa.
| | - Michael Simon
- Fort Hare Institute of Technology, University of Fort Hare, Alice Campus, Alice 5700, Eastern Cape Province, South Africa.
| | - Anthony I Okoh
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice Campus, Alice 5700, Eastern Cape Province, South Africa.
- South Africa Medical Research Council Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, Eastern Cape Province, South Africa.
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16
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Cordero N, Maza F, Navea-Perez H, Aravena A, Marquez-Fontt B, Navarrete P, Figueroa G, González M, Latorre M, Reyes-Jara A. Different Transcriptional Responses from Slow and Fast Growth Rate Strains of Listeria monocytogenes Adapted to Low Temperature. Front Microbiol 2016; 7:229. [PMID: 26973610 PMCID: PMC4772535 DOI: 10.3389/fmicb.2016.00229] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 02/12/2016] [Indexed: 01/12/2023] Open
Abstract
Listeria monocytogenes has become one of the principal foodborne pathogens worldwide. The capacity of this bacterium to grow at low temperatures has opened an interesting field of study in terms of the identification and classification of new strains of L. monocytogenes with different growth capacities at low temperatures. We determined the growth rate at 8°C of 110 strains of L. monocytogenes isolated from different food matrices. We identified a group of slow and fast strains according to their growth rate at 8°C and performed a global transcriptomic assay in strains previously adapted to low temperature. We then identified shared and specific transcriptional mechanisms, metabolic and cellular processes of both groups; bacterial motility was the principal process capable of differentiating the adaptation capacity of L. monocytogenes strains with different ranges of tolerance to low temperatures. Strains belonging to the fast group were less motile, which may allow these strains to achieve a greater rate of proliferation at low temperature.
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Affiliation(s)
- Ninoska Cordero
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile Santiago, Chile
| | - Felipe Maza
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile Santiago, Chile
| | - Helen Navea-Perez
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile Santiago, Chile
| | - Andrés Aravena
- Department of Molecular Biology and Genetics, Istanbul University Istanbul, Turkey
| | - Bárbara Marquez-Fontt
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile Santiago, Chile
| | - Paola Navarrete
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile Santiago, Chile
| | - Guillermo Figueroa
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile Santiago, Chile
| | - Mauricio González
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de ChileSantiago, Chile; Center for Genome Regulation (Fondap 15090007), Universidad de ChileSantiago, Chile
| | - Mauricio Latorre
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de ChileSantiago, Chile; Center for Genome Regulation (Fondap 15090007), Universidad de ChileSantiago, Chile; Mathomics, Center for Mathematical Modeling, Universidad de ChileSantiago, Chile
| | - Angélica Reyes-Jara
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile Santiago, Chile
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17
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Tripathy S, Padhi SK, Sen R, Mohanty S, Samanta M, Maiti NK. Profiling of Brevibacillus borstelensis transcriptome exposed to high temperature shock. Genomics 2015; 107:33-9. [PMID: 26585522 DOI: 10.1016/j.ygeno.2015.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 11/06/2015] [Accepted: 11/13/2015] [Indexed: 10/22/2022]
Abstract
To understand the molecular mechanisms underlying the ability of the bacteria to survive at high temperature, gene expression profile of Brevibacillusborstelensis at 55°C during 5 and 10min heat shock period was carried out by high-throughput sequencing technology. A total of 2555 non-redundant transcripts were annotated. A total of 575 genes at 5min and 400 genes at 10min exhibited significant differential expression in response to temperature upshift from 50 to 55°C. Genes up-regulated under heat shock were associated with metabolism (mtnE), membrane transport, signal transduction, transcriptional regulation (ycxD, codY) and folding and sorting (hsp90). A larger number of genes encoding hypothetical proteins were identified. RT-PCR experimental results carried out on genes expressed under heat shock were found to be consistent with transcriptome data. The results enhance our understanding of adaptation strategy of thermophilic bacteria thereby providing a strong background for in depth research in thermophiles.
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Affiliation(s)
- S Tripathy
- Division of Fish Health Management, Central Institute of Freshwater Aquaculture, Kaushalyaganga, Bhubaneswar 751002, Orissa, India
| | - S K Padhi
- Division of Fish Health Management, Central Institute of Freshwater Aquaculture, Kaushalyaganga, Bhubaneswar 751002, Orissa, India
| | - R Sen
- Division of Fish Health Management, Central Institute of Freshwater Aquaculture, Kaushalyaganga, Bhubaneswar 751002, Orissa, India
| | - S Mohanty
- Division of Fish Health Management, Central Institute of Freshwater Aquaculture, Kaushalyaganga, Bhubaneswar 751002, Orissa, India
| | - M Samanta
- Division of Fish Health Management, Central Institute of Freshwater Aquaculture, Kaushalyaganga, Bhubaneswar 751002, Orissa, India
| | - N K Maiti
- Division of Fish Health Management, Central Institute of Freshwater Aquaculture, Kaushalyaganga, Bhubaneswar 751002, Orissa, India.
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18
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Jones GS, D’Orazio SE. Listeria monocytogenes: cultivation and laboratory maintenance. CURRENT PROTOCOLS IN MICROBIOLOGY 2013; 31:9B.2.1-9B.2.7. [PMID: 24510292 PMCID: PMC3920655 DOI: 10.1002/9780471729259.mc09b02s31] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This unit describes general procedures for the lab cultivation and storage of the Gram-positive facultative intracellular bacterium Listeria monocytogenes. The basic protocols are relevant for a wide scope of applications including microbial genetics and both in vitro and in vivo infection studies. Commonly used L. monocytogenes strains, serotypes, and growth parameters are also discussed.
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Affiliation(s)
- Grant S. Jones
- Department of Microbiology, Immunology & Molecular Genetics,
University of Kentucky, 800 Rose Street – MS431, Lexington, KY
40536
| | - Sarah E.F. D’Orazio
- Department of Microbiology, Immunology & Molecular Genetics,
University of Kentucky, 800 Rose Street – MS431, Lexington, KY
40536
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19
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An internalin a probe-based genosensor for Listeria monocytogenes detection and differentiation. BIOMED RESEARCH INTERNATIONAL 2013; 2013:640163. [PMID: 23586053 PMCID: PMC3618917 DOI: 10.1155/2013/640163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/13/2013] [Accepted: 02/22/2013] [Indexed: 11/18/2022]
Abstract
Internalin A (InlA), a protein required for Listeria monocytogenes virulence, is encoded by the inlA gene, which is only found in pathogenic strains of this genus. One of the best ways to detect and confirm the pathogenicity of the strain is the detection of one of the virulence factors produced by the microorganism. This paper focuses on the design of an electrochemical genosensor used to detect the inlA gene in Listeria strains without labelling the target DNA. The electrochemical sensor was obtained by immobilising an inlA gene probe (single-stranded oligonucleotide) on the surfaces of screen-printed gold electrodes (Au-SPEs) by means of a mercaptan-activated self-assembled monolayer (SAM). The hybridisation reaction occurring on the electrode surface was electrochemically transduced by differential pulse voltammetry (DPV) using methylene blue (MB) as an indicator. The covalently immobilised single-stranded DNA was able to selectively hybridise to its complementary DNA sequences in solution to form double-stranded DNA on the gold surface. A significant decrease of the peak current of the voltammogram (DPV) upon hybridisation of immobilised ssDNA was recorded. Whole DNA samples of L. monocytogenes strains could be discriminated from other nonpathogenic Listeria species DNA with the inlA gene DNA probe genosensor.
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20
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Azizoglu RO, Lyman R, Anderson KL. Bovine Staphylococcus aureus: dose response to iodine and chlorhexidine and effect of iodine challenge on antibiotic susceptibility. J Dairy Sci 2012; 96:993-9. [PMID: 23261384 DOI: 10.3168/jds.2012-5857] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/12/2012] [Indexed: 01/16/2023]
Abstract
Staphylococcus aureus is a gram-positive organism that is frequently associated with clinical or subclinical mastitis. The use of germicidal teat dips is one of the measures taken by the dairy industry to control mastitis. Iodine and chlorhexidine compounds are commonly used disinfectants in teat dips. We determined the minimum inhibitory concentrations (MIC) of iodine for 37 isolates of Staph. aureus and observed variations in MIC. Seven of these Staph. aureus isolates were selected as genotype group representatives based on their pulsed-field gel electrophoresis patterns. Dose responses against iodine and chlorhexidine were determined for the 7 genotype group representatives. The response of these isolates to iodine varied significantly, whereas all isolates were susceptible to chlorhexidine, even at concentrations as low as 0.0002%. We also evaluated whether exposure of Staph. aureus to sublethal levels of iodine influenced subsequent antibiotic susceptibility. No differences in antibiotic susceptibility of Staph. aureus were observed among cultures grown in brain heart infusion broth with and without supplemental iodine. The observed variation in iodine dose responses of Staph. aureus may have implications for the occurrence of Staph. aureus mastitis on dairy farms.
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Affiliation(s)
- Reha Onur Azizoglu
- Milk Microbiology and Mastitis Laboratory, Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC 27606, USA.
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21
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Markkula A, Mattila M, Lindström M, Korkeala H. Genes encoding putative DEAD-box RNA helicases in Listeria monocytogenes EGD-e are needed for growth and motility at 3°C. Environ Microbiol 2012; 14:2223-32. [PMID: 22564273 DOI: 10.1111/j.1462-2920.2012.02761.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Quantitative RT-PCR revealed that transcripts of all four putative DEAD-box RNA helicase genes of the psychrotrophic pathogen Listeria monocytogenes EGD-e are found at higher levels in organisms grown at 3°C than at 37°C. At 3°C, growth of the three corresponding gene deletion mutants Δlmo0866, Δlmo1450 and Δlmo1722 was clearly restricted. The minimum growth temperatures of the three mutants were also higher than that of the wild-type EGD-e. In addition to inability to grow at 3°C, growth of Δlmo0866 and Δlmo1722 was reduced at 25°C, suggesting special roles of Lmo0866 and Lmo1722 in growth at suboptimal temperatures. Growth of Δlmo1450 was restricted not only at 3°C and 25°C, but also at 37°C, suggesting that Lmo1450 plays a universal role in growth of L. monocytogenes EGD-e. Moreover, cold-sensitive Δlmo0866, Δlmo1450 and Δlmo1722 were impaired in motility. The Δlmo0866 and Δlmo1450 strains were non-motile, while Δlmo1722 showed reduced motility. This study shows that the putative DEAD-box RNA helicase genes lmo0866, lmo1450 and lmo1722 are necessary for cold tolerance and motility of L. monocytogenes EGD-e.
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Affiliation(s)
- Annukka Markkula
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, PO Box 66, FI-00014 University of Helsinki, Finland.
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22
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Li JS, Bi YT, Dong C, Yang JF, Liang WD. Transcriptome analysis of adaptive heat shock response of Streptococcus thermophilus. PLoS One 2011; 6:e25777. [PMID: 22022447 PMCID: PMC3192767 DOI: 10.1371/journal.pone.0025777] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 09/09/2011] [Indexed: 11/18/2022] Open
Abstract
Streptococcus thermophilus, a gram-positive facultative anaerobe, is one of the most important lactic acid bacteria widely used in the dairy fermentation industry. In this study, we have analyzed the global transcriptional profiling of S. thermophilus upon temperature change. During a temperature shift from 42°C to 50°C, it is found that 196 (10.4%) genes show differential expression with 102 up-regulated and 94 down-regulated at 50°C. In particular, 1) Heat shock genes, such as DnaK, GroESL and clpL, are identified to be elevated at 50°C; 2) Transcriptional regulators, such as HrcA, CtsR, Fur, MarR and MerR family, are differentially expressed, indicating the complex molecular mechanisms of S. thermophilus adapting to heat shock; 3) Genes associated with signal transduction, cell wall genes, iron homeostasis, ABC transporters and restriction-modification system were induced; 4) A large number of the differentially expressed genes are hypothetical genes of unknown function, indicating that much remains to be investigated about the heat shock response of S. thermophilus. Experimental investigation of selected heat shock gene ClpL shows that it plays an important role in the physiology of S. thermophilus at high temperature and meanwhile we confirmed ClpL as a member of the CtsR regulon. Overall, this study has contributed to the underlying adaptive molecular mechanisms of S. thermophilus upon temperature change and provides a basis for future in-depth functional studies.
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Affiliation(s)
- Jin-song Li
- College of Life Science, Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical College, Wenzhou, China
| | - Yun-tian Bi
- School of Basic Medical Science, Wenzhou Medical College, Wenzhou, China
| | - Cheng Dong
- Cardiovascular Surgery, The Fourth Hospital of Harbin Medical University, Harbin, China
| | - Ji-feng Yang
- College of Life Science, Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical College, Wenzhou, China
| | - Wan-dong Liang
- College of Life Science, Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical College, Wenzhou, China
- * E-mail:
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23
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Johnson PV, Blair BM, Zeller S, Kotton CN, Hohmann EL. Attenuated Listeria monocytogenes vaccine vectors expressing influenza A nucleoprotein: preclinical evaluation and oral inoculation of volunteers. Microbiol Immunol 2011; 55:304-17. [PMID: 21338384 DOI: 10.1111/j.1348-0421.2011.00322.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Listeria monocytogenes vectors have shown promise for delivery of viral and tumor antigens in animals. We used two mutant vector strains deleted for actA/plcB (BMB72) and actA/inlB (BMB54), and engineered both strains to secrete a heterologous nucleoprotein antigen from the Influenza A virus. Strains were evaluated in vitro and in mice. Twenty-two healthy volunteers received single oral doses of either strain in a physiological study of safety, shedding, and immunogenicity. Volunteers were observed in the hospital for seven days and had daily blood cultures, routine safety blood tests (complete blood count with differential; hepatic and renal function), and fecal cultures; none had fever, positive blood cultures, prolonged shedding, or serious or unexpected events. Four of 12 volunteers who received the actA/plcB-deleted strain had minor, transient, asymptomatic serum transaminase elevations (maximum increase 1.4× upper normal). Six of six volunteers who received ≥4 × 10(9) colony forming units had detectable mucosal immune responses to listerial antigens, but not to the vectored influenza antigen. Approximately half the volunteers had modest interferon-γ ELISpot responses to a complex listerial antigen, but none had increases over their baseline responses to the influenza antigen. Comparison with prior work suggests that foreign antigen expression, and perhaps also freezing, may adversely affect the organisms' immunogenicity.
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Affiliation(s)
- Paul V Johnson
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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24
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Azizoglu RO, Kathariou S. Impact of growth temperature and agar versus liquid media on freeze-thaw tolerance of Yersinia enterocolitica. Foodborne Pathog Dis 2010; 7:1125-8. [PMID: 20528173 DOI: 10.1089/fpd.2009.0526] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Yersinia enterocolitica is a foodborne pathogen well known for its ability to grow at low temperatures. Recent studies with another psychrotrophic foodborne pathogen, Listeria monocytogenes, revealed that temperature of growth had pronounced impact on survival following repeated freezing and thawing (cryotolerance). Listerial cryotolerance was significantly more pronounced when bacteria were grown at 37 degrees C than following growth at either 4 degrees C or 25 degrees C. However, it is not known whether such impact of growth temperature is a general adaptation shared with other foodborne pathogens. In this study, we investigated the impact of growth temperature (4 degrees C, 25 degrees C, and 37 degrees C) on cryotolerance of Y. enterocolitica. In strong contrast to findings previously obtained with Listeria spp., cryotolerance of Y. enterocolitica was impaired following growth in liquid media at 37 degrees C, with cell concentration dropping to undetectable levels (<10(1) colony forming unit/mL) following as few as six freeze-thaw cycles. On the other hand, when the bacteria were grown at 4 degrees C, cryotolerance was significantly higher (p < 0.05), and substantial survival was maintained even after 18 cycles (2-5 log reduction, depending on strain). Enhanced cryotolerance was also observed with cultures grown at 25 degrees C. Bacteria grown at 37 degrees C on agar were significantly more cryotolerant than following growth at 37 degrees C in liquid media (p < 0.05). The data suggest species-specific impact of growth temperature and liquid versus agar medium on cryotolerance of cold-tolerant bacteria.
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Affiliation(s)
- Reha Onur Azizoglu
- Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina 27695-7624, USA
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25
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Temperature-dependent requirement for catalase in aerobic growth of Listeria monocytogenes F2365. Appl Environ Microbiol 2010; 76:6998-7003. [PMID: 20817809 DOI: 10.1128/aem.01223-10] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Listeria monocytogenes is a Gram-positive, psychrotrophic, facultative intracellular food-borne pathogen responsible for severe illness (listeriosis). The bacteria can grow in a wide range of temperatures (1 to 45°C), and low-temperature growth contributes to the food safety hazards associated with contamination of ready-to-eat foods with this pathogen. To assess the impact of oxidative stress responses on the ability of L. monocytogenes to grow at low temperatures and to tolerate repeated freeze-thaw stress (cryotolerance), we generated and characterized a catalase-deficient mutant of L. monocytogenes F2365 harboring a mariner-based transposon insertion in the catalase gene (kat). When grown aerobically on blood-free solid medium, the kat mutant exhibited impaired growth, with the extent of impairment increasing with decreasing temperature, and no growth was detected at 4°C. Aerobic growth in liquid was impaired at 4°C, especially under aeration, but not at higher temperatures (10, 25, or 37°C). Genetic complementation of the mutant with the intact kat restored normal growth, confirming that inactivation of this gene was responsible for the growth impairment. In spite of the expected impact of oxidative stress responses on cryotolerance, cryotolerance of the kat mutant was not affected.
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26
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Kuenne C, Voget S, Pischimarov J, Oehm S, Goesmann A, Daniel R, Hain T, Chakraborty T. Comparative analysis of plasmids in the genus Listeria. PLoS One 2010; 5:e12511. [PMID: 20824078 PMCID: PMC2932693 DOI: 10.1371/journal.pone.0012511] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 08/10/2010] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND We sequenced four plasmids of the genus Listeria, including two novel plasmids from L. monocytogenes serotype 1/2c and 7 strains as well as one from the species L. grayi. A comparative analysis in conjunction with 10 published Listeria plasmids revealed a common evolutionary background. PRINCIPAL FINDINGS All analysed plasmids share a common replicon-type related to theta-replicating plasmid pAMbeta1. Nonetheless plasmids could be broadly divided into two distinct groups based on replicon diversity and the genetic content of the respective plasmid groups. Listeria plasmids are characterized by the presence of a large number of diverse mobile genetic elements and a commonly occurring translesion DNA polymerase both of which have probably contributed to the evolution of these plasmids. We detected small non-coding RNAs on some plasmids that were homologous to those present on the chromosome of L. monocytogenes EGD-e. Multiple genes involved in heavy metal resistance (cadmium, copper, arsenite) as well as multidrug efflux (MDR, SMR, MATE) were detected on all listerial plasmids. These factors promote bacterial growth and survival in the environment and may have been acquired as a result of selective pressure due to the use of disinfectants in food processing environments. MDR efflux pumps have also recently been shown to promote transport of cyclic diadenosine monophosphate (c-di-AMP) as a secreted molecule able to trigger a cytosolic host immune response following infection. CONCLUSIONS The comparative analysis of 14 plasmids of genus Listeria implied the existence of a common ancestor. Ubiquitously-occurring MDR genes on plasmids and their role in listerial infection now deserve further attention.
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Affiliation(s)
- Carsten Kuenne
- Institute of Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Sonja Voget
- Goettingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August University Goettingen, Goettingen, Germany
| | - Jordan Pischimarov
- Institute of Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Sebastian Oehm
- Bioinformatics Resource Facility, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Alexander Goesmann
- Bioinformatics Resource Facility, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Rolf Daniel
- Goettingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August University Goettingen, Goettingen, Germany
| | - Torsten Hain
- Institute of Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Trinad Chakraborty
- Institute of Medical Microbiology, Justus-Liebig University, Giessen, Germany
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Azizoglu RO, Kathariou S. Inactivation of a cold-induced putative rna helicase gene of Listeria monocytogenes is accompanied by failure to grow at low temperatures but does not affect freeze-thaw tolerance. J Food Prot 2010; 73:1474-9. [PMID: 20819357 DOI: 10.4315/0362-028x-73.8.1474] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Freeze-thaw tolerance (cryotolerance) of Listeria monocytogenes is markedly influenced by temperature of growth of the bacteria, and may involve responses to low-temperature stresses encountered during freezing and thawing. A cold-sensitive mariner-based transposon mutant of L. monocytogenes F2365 was found to harbor a single insertion in LMOf2365_1746, encoding a putative RNA helicase, and earlier shown by other investigators to be induced during 4 degrees C growth of L. monocytogenes. The mutant had normal growth at 37 degrees C but completely failed to grow at either 4 or 10 degrees C, and had impaired growth and reduced swarming on soft agar at 25 degrees C. However, the mutation had no discernible influence on the ability of the bacteria to tolerate repeated freezing and thawing after growth at either 25 or 37 degrees C. The findings suggest that the transposon insertion in the putative helicase gene, in spite of the severely cold-sensitive phenotype that accompanies it, does not affect the ability of the bacteria to cope with cold-related stresses encountered during repeated freezing and thawing.
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Affiliation(s)
- Reha O Azizoglu
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
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28
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Occurrence and genetic relatedness of Listeria spp. in two brands of locally processed ready-to-eat meats in Trinidad. Epidemiol Infect 2010; 139:718-27. [PMID: 20663259 DOI: 10.1017/s095026881000172x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Contamination of locally produced, ready-to-eat meats by Listeria spp. has been previously reported at one processing plant in Trinidad. However, the status of this pathogen in locally produced products sold at retail outlets is unknown. This study was conducted to establish whether there is a risk to consumers of locally processed meats caused by the presence of Listeria spp., and whether a link exists between the presence of the pathogen in retail products and the manufacturing plant of one brand (B). Four hundred and eighty ready-to-eat meat products of two popular local brands (A and B) were collected from retail outlets and analysed for the presence of Listeria spp. together with food samples and surfaces from one manufacturing plant (B). Eighty-eight of the retail products (18·3%) were contaminated with Listeria spp., of which, 52·3% were L. innocua, 44·3% were L. monocytogenes and 3·4% belonged to the L. seeligeri-L. welshimeri-L. ivanovii (Siwi) group. L. innocua was found in 15 in-process food samples and on three surfaces of equipment at plant B. Four in-process food samples were also contaminated with Siwi isolates. Repetitive extragenic palindromic PCR DNA fingerprinting showed a possible association between strains of different Listeria spp. and brand as well as with manufacturing plant B.
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Segawa T, Takeuchi N, Ushida K, Kanda H, Kohshima S. Altitudinal changes in a bacterial community on Gulkana Glacier in Alaska. Microbes Environ 2010; 25:171-82. [PMID: 21576870 DOI: 10.1264/jsme2.me10119] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To clarify altitudinal changes in the bacterial community on Gulkana Glacier in Alaska, we analyzed bacterial 16S rRNA gene by low-cycle PCR amplification, denaturing gradient gel electrophoresis (DGGE), and culturing in a snowmelt medium at 4°C. Low-cycle PCR-based cloning revealed the presence of 100 bacterial OTUs; however, 41 OTUs were identified only in a single clone, suggesting that their abundance was limited because of difficulty in predominating on the glacier. In contrast, 17 major OTUs accounted for 57-87% of the clone library at each site, suggesting that they accounted for the major part of the bacteria on the glacier. In addition, five of the 17 OTUs were included in the 21 OTUs cultured in the snowmelt medium. Based on the dominant phylotypes and DGGE results, the bacterial community on the glacier could be divided into three types, corresponding to the snow-covered, snow- and ice-covered, and bare-ice areas of the glacier. Our results suggest that a relatively limited number of bacteria predominate and that each phylotype is adapted to a distinct set of conditions on the glacier.
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Affiliation(s)
- Takahiro Segawa
- Transdisciplinary Research Integration Center, 4–3–13 Toranomon, Minato-ku, Tokyo 105–0001, Japan.
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