scholarly journals An antimicrobial peptide specifically active against Listeria monocytogenes is secreted by Bacillus pumilus SF214

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Anella Saggese ◽  
Ylenia De Luca ◽  
Loredana Baccigalupi ◽  
Ezio Ricca
Keyword(s):  
Listeria Monocytogenes ◽  
Bacillus Pumilus ◽  
Close Relative ◽  
Resting Cells ◽  
Gram Negative Bacteria ◽  
Chemical Treatments ◽  
Food Borne ◽  
Wide Range ◽  
Ph Conditions ◽  
Strict Specificity

Abstract Background Members of the Bacillus genus produce a large variety of antimicrobial peptides including linear or cyclic lipopeptides and thiopeptides, that often have a broad spectrum of action against Gram-positive and Gram-negative bacteria. We have recently reported that SF214, a marine isolated strain of Bacillus pumilus, produces two different antimicrobials specifically active against either Staphylococcus aureus or Listeria monocytogenes. The anti-Staphylococcus molecule has been previously characterized as a pumilacidin, a nonribosomally synthesized lipopetide composed of a mixture of cyclic heptapeptides linked to fatty acids of variable length. Results Our analysis on the anti-Listeria molecule of B. pumilus SF214 indicated that it is a peptide slightly smaller than 10 kDa, produced during the exponential phase of growth, stable at a wide range of pH conditions and resistant to various chemical treatments. The peptide showed a lytic activity against growing but not resting cells of Listeria monocytogenes and appeared extremely specific being inactive also against L. innocua, a close relative of L. monocytogenes. Conclusions These findings indicate that the B. pumilus peptide is unusual with respect to other antimicrobials both for its time of synthesis and secretion and for its strict specificity against L. monocytogenes. Such specificity, together with its stability, propose this new antimicrobial as a tool for potential biotechnological applications in the fight against the dangerous food-borne pathogen L. monocytogenes.

scholarly journals Use of Monoclonal Antibodies That Recognize p60 for Identification of Listeria monocytogenes

2004 ◽  
Vol 11 (3) ◽  
pp. 446-451 ◽  
Author(s):  
Kang-Y. Yu ◽  
Youngsoon Noh ◽  
Minsub Chung ◽  
Hong-J. Park ◽  
Namseok Lee ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Protein Gene ◽  
Enzyme Linked Immunosorbent Assay ◽  
Identification System ◽  
Growth Media ◽  
Detection Systems ◽  
Food Borne ◽  
Wide Range ◽  
Excess Amount ◽  
Immunological Identification

ABSTRACT Listeria monocytogenes causes major food-borne outbreaks of disease worldwide. Specific identification of this microorganism is of utmost importance to public health and industry. Listeria species are known to secrete a 60-kDa protein collectively termed p60, which is encoded by the iap (invasion-associated protein) gene and secreted in large quantities into the growth media. p60 is a highly immunogenic murein hydrolase that is essential for cell division. Due to these properties, p60 is an ideal diagnostic target for the development of immunological detection systems for L. monocytogenes. We report here two independent lines of monoclonal antibody (MAb): p6007, which specifically recognizes L. monocytogenes p60, and p6017, which reacts with a wide range of Listeria p60 proteins. By combining these antibodies with a polyclonal antibody, we developed efficient sandwich enzyme-linked immunosorbent assay (ELISA) systems which can specifically identify L. monocytogenes or generally detect Listeria species. Since an excess amount of the peptide corresponding to PepA or PepD did not interfere with the ELISA, and direct ELISAs were unable to detect both peptides, we concluded that the epitope presumed to be recognized by p6007 or p6017 could be distinguished from PepA and PepD as described by Bubert et al. (Appl. Environ. Microbiol. 60:3120-3127, 1997). To our best knowledge, this is the first example of an immunological identification system that uses p60-recognizing MAbs.

Radiosensitivity of Listeria monocytogenes at Various Temperatures and Cell Concentrations

1995 ◽  
Vol 58 (7) ◽  
pp. 748-751 ◽  
Author(s):  
LINDA S. ANDREWS ◽  
DOUGLAS L. MARSHALL ◽  
ROBERT M. GRODNER
Keyword(s):  
Regression Analysis ◽  
Listeria Monocytogenes ◽  
Total Dose ◽  
Gram Negative Bacteria ◽  
Initial Cell Concentration ◽  
Food Borne ◽  
Colony Forming Units ◽  
Radiation Resistant ◽  
D Values ◽  
D Value

Among food-borne pathogens, Listeria monocytogenes is more radiation resistant than gram-negative bacteria of the genera Salmonella and Vibrio. This study was designed to determine if initial cell concentration and/or temperature at the time of irradiation influences the radiosensitivity of L. monocytogenes. Concentrations of 103, 106, and 109 CFU (colony-forming units)/ml of L. monocytogenes Scott A were suspended in tryptic soy broth and exposed to 0 to 5 kGy of gamma radiation (1.25 MeV) at 20, 4, and −80°C. Survivors were enumerated and irradiation D-values were calculated using regression analysis and total-dose methods. A 103 CFU/ml population was destroyed with a <2 kGy dose. The irradiation D-value of 0.43 kGy when calculated by regression analysis for frozen (−80°C) cultures of 106 CFU/ml was significantly lower (P < 0.05) than those (0.58 and 0.62 kGy) at 20° and 4°C, respectively. However, the −80°C D-value was not significantly different (0.61 kGy) when calculated by the total dose required to eliminate all recovery. At 109 CFU/ml, a D-value (calculated by both methods) of 0.42 kGy was obtained at both 4° and −80°C, which was significantly lower (P < 0.05) than 0.50 kGy for 20°C suspensions. The temperature of irradiation only influenced the radiosensitivity of L. monocytogenes at 109 CFU/ml.

Biofilm Formation and Associated Genes in Listeria Monocytogenes

2017 ◽  
Vol 12 (3) ◽  
Author(s):  
S. R. Warke ◽  
V. C. Ingle ◽  
N. V. Kurkure ◽  
P. A. Tembhurne ◽  
Minakshi Prasad ◽  
...  
Keyword(s):  
Public Health ◽  
Listeria Monocytogenes ◽  
Multiplex Pcr ◽  
Food Processing ◽  
Biofilm Formation ◽  
Milk Samples ◽  
Biofilm Production ◽  
Food Borne ◽  
Serious Infections ◽  
Microtiter Assay

Listeria monocytogenes, an opportunistic food borne pathogen can cause serious infections in immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments.The biofilm transfers contamination to food products and impose risk to public health. In the present study biofilm producing ability of L. monocytogenes isolates were investigated phenotypically and genotypically by microtiter assay and multiplex PCR, respectively. Out of 38 L. monocytogenes isolates 14 were recovered from animal clinical cases, 12 bovine environment and 12 from milk samples. A total of 3 (21.42%) clinical, 2 (16.66%) environment and 3 (25%) milk samples respectively, revealed biofilm production in microtiter assay. Cumulative results showed that 23 (60.52%) out of 38 strains of L. monocytogenes were positive for luxS and flaA gene and 1 (2.63%) was positive only for the flaA gene.

scholarly journals Responses to Ecopollutants and Pathogenization Risks of Saprotrophic Rhodococcus Species

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 974
Author(s):  
Irina B. Ivshina ◽  
Maria S. Kuyukina ◽  
Anastasiia V. Krivoruchko ◽  
Elena A. Tyumina
Keyword(s):  
Survival Strategies ◽  
Complex Life Cycle ◽  
Anthropogenic Pressure ◽  
Resting Cells ◽  
Organic Substrates ◽  
Negative Effects ◽  
Anthropogenic Pollutants ◽  
Rhodococcus Species ◽  
Wide Range ◽  
Rigid Cell Wall

Under conditions of increasing environmental pollution, true saprophytes are capable of changing their survival strategies and demonstrating certain pathogenicity factors. Actinobacteria of the genus Rhodococcus, typical soil and aquatic biotope inhabitants, are characterized by high ecological plasticity and a wide range of oxidized organic substrates, including hydrocarbons and their derivatives. Their cell adaptations, such as the ability of adhering and colonizing surfaces, a complex life cycle, formation of resting cells and capsule-like structures, diauxotrophy, and a rigid cell wall, developed against the negative effects of anthropogenic pollutants are discussed and the risks of possible pathogenization of free-living saprotrophic Rhodococcus species are proposed. Due to universal adaptation features, Rhodococcus species are among the candidates, if further anthropogenic pressure increases, to move into the group of potentially pathogenic organisms with “unprofessional” parasitism, and to join an expanding list of infectious agents as facultative or occasional parasites.

scholarly journals Effect of Gaseous Ozone on Listeria monocytogenes Planktonic Cells and Biofilm: An In Vitro Study

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1484
Author(s):  
Felice Panebianco ◽  
Selene Rubiola ◽  
Francesco Chiesa ◽  
Tiziana Civera ◽  
Pierluigi Aldo Di Ciccio
Keyword(s):  
Listeria Monocytogenes ◽  
In Vitro Study ◽  
Planktonic Cells ◽  
Free Living ◽  
Biofilm Inhibition ◽  
Additional Tool ◽  
Complete Inactivation ◽  
Gaseous Ozone ◽  
Food Borne

Among food-borne pathogens, Listeria monocytogenes continues to pose concerns to food business operators due to its capacity to form biofilm in processing environments. Ozone may be an eco-friendly technology to control microbial contaminations, but data concerning its effect on Listeria monocytogenes biofilm are still limited. In this study, the effect of gaseous ozone at 50 ppm on planktonic cells and biofilm of reference and food-related Listeria monocytogenes strains was evaluated. Ozone caused a reduction in microbial loads of 3.7 ± 0.4 and 3.9 ± 0.4 Log10 CFU/mL after 10 and 30 min, respectively. A complete inactivation of planktonic cells after 6 h of treatment was observed. Biofilm inhibition and eradication treatments (50 ppm, 6 h) resulted in a significant decrease of the biofilm biomass for 59% of the strains tested, whilst a slight dampening of live cell loads in the biofilm state was observed. In conclusion, gaseous ozone is not sufficient to completely counteract Listeria monocytogenes biofilm, but it may be useful as an additional tool to contrast Listeria monocytogenes free-living cells and to improve the existing sanitization procedures in food processing environments.

scholarly journals Not Just Transporters: Alternative Functions of ABC Transporters in Bacillus subtilis and Listeria monocytogenes

2021 ◽  
Vol 9 (1) ◽  
pp. 163
Author(s):  
Jeanine Rismondo ◽  
Lisa Maria Schulz
Keyword(s):  
Bacillus Subtilis ◽  
Listeria Monocytogenes ◽  
Abc Transporters ◽  
Organic Molecules ◽  
Atp Hydrolysis ◽  
The Past ◽  
Wide Range ◽  
Regulatory Functions ◽  
Complex Organic ◽  
Detoxification Mechanisms

ATP-binding cassette (ABC) transporters are usually involved in the translocation of their cognate substrates, which is driven by ATP hydrolysis. Typically, these transporters are required for the import or export of a wide range of substrates such as sugars, ions and complex organic molecules. ABC exporters can also be involved in the export of toxic compounds such as antibiotics. However, recent studies revealed alternative detoxification mechanisms of ABC transporters. For instance, the ABC transporter BceAB of Bacillus subtilis seems to confer resistance to bacitracin via target protection. In addition, several transporters with functions other than substrate export or import have been identified in the past. Here, we provide an overview of recent findings on ABC transporters of the Gram-positive organisms B. subtilis and Listeria monocytogenes with transport or regulatory functions affecting antibiotic resistance, cell wall biosynthesis, cell division and sporulation.

scholarly journals Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Biologics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 164-176
Author(s):  
Abdallah S. Abdelsattar ◽  
Anan Safwat ◽  
Rana Nofal ◽  
Amera Elsayed ◽  
Salsabil Makky ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Salmonella Spp ◽  
Isolation And Characterization ◽  
Food Borne ◽  
Wide Range ◽  
Almost All ◽  
And Control ◽  
Milk And Dairy Products

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (<48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life.

scholarly journals Gbu Glycine Betaine Porter and Carnitine Uptake in Osmotically Stressed Listeria monocytogenes Cells

2002 ◽  
Vol 68 (11) ◽  
pp. 5647-5655 ◽  
Author(s):  
Mary Lou Mendum ◽  
Linda Tombras Smith
Keyword(s):  
Listeria Monocytogenes ◽  
Transport System ◽  
Glycine Betaine ◽  
Compatible Solutes ◽  
High Salt ◽  
Uptake System ◽  
Food Borne ◽  
Protein Mutants ◽  
Carnitine Uptake ◽  
Do So

ABSTRACT The food-borne pathogen Listeria monocytogenes grows actively under high-salt conditions by accumulating compatible solutes such as glycine betaine and carnitine from the medium. We report here that the dominant transport system for glycine betaine uptake, the Gbu porter, may act as a secondary uptake system for carnitine, with a Km of 4 mM for carnitine uptake and measurable uptake at carnitine concentrations as low as 10 μM. This porter has a Km for glycine betaine uptake of about 6 μM. The dedicated carnitine porter, OpuC, has a Km for carnitine uptake of 1 to 3 μM and a V max of approximately 15 nmol/min/mg of protein. Mutants lacking either opuC or gbu were used to study the effects of four carnitine analogs on growth and uptake of osmolytes. In strain DP-L1044, which had OpuC and the two glycine betaine porters Gbu and BetL, triethylglycine was most effective in inhibiting growth in the presence of glycine betaine, but trigonelline was best at inhibiting growth in the presence of carnitine. Carnitine uptake through OpuC was inhibited by γ-butyrobetaine. Dimethylglycine inhibited both glycine betaine and carnitine uptake through the Gbu porter. Carnitine uptake through the Gbu porter was inhibited by triethylglycine. Glycine betaine uptake through the BetL porter was strongly inhibited by trigonelline and triethylglycine. These results suggest that it is possible to reduce the growth of L. monocytogenes under osmotically stressful conditions by inhibiting glycine betaine and carnitine uptake but that to do so, multiple uptake systems must be affected.

scholarly journals A Rapid and Sensitive Europium Nanoparticle-Based Lateral Flow Immunoassay Combined with Recombinase Polymerase Amplification for Simultaneous Detection of Three Food-Borne Pathogens

2021 ◽  
Vol 18 (9) ◽  
pp. 4574
Author(s):  
Kai Chen ◽  
Biao Ma ◽  
Jiali Li ◽  
Erjing Chen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Simultaneous Detection ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Quantitative Detection ◽  
Bacterial Strains ◽  
Food Borne Pathogens ◽  
Food Borne

Food-borne pathogens have become an important public threat to human health. There are many kinds of pathogenic bacteria in food consumed daily. A rapid and sensitive testing method for multiple food-borne pathogens is essential. Europium nanoparticles (EuNPs) are used as fluorescent probes in lateral flow immunoassays (LFIAs) to improve sensitivity. Here, recombinase polymerase amplification (RPA) combined with fluorescent LFIA was established for the simultaneous and quantitative detection of Listeria monocytogenes, Vibrio parahaemolyticus, and Escherichia coliO157:H7. In this work, the entire experimental process could be completed in 20 min at 37 °C. The limits of detection (LODs) of EuNP-based LFIA–RPA were 9.0 colony-forming units (CFU)/mL for Listeria monocytogenes, 7.0 CFU/mL for Vibrio parahaemolyticus, and 4.0 CFU/mL for Escherichia coliO157:H7. No cross-reaction could be observed in 22 bacterial strains. The fluorescent LFIA–RPA assay exhibits high sensitivity and good specificity. Moreover, the average recovery of the three food-borne pathogens spiked in food samples was 90.9–114.2%. The experiments indicate the accuracy and reliability of the multiple fluorescent test strips. Our developed EuNP-based LFIA–RPA assay is a promising analytical tool for the rapid and simultaneous detection of multiple low concentrations of food-borne pathogens.

Inactivation of Salmonella Species and Other Food-Borne Pathogens with Salmide®, a Sodium Chlorite–Based Oxyhalogen Disinfectant†

1995 ◽  
Vol 58 (5) ◽  
pp. 535-540 ◽  
Author(s):  
JAIME MULLERAT ◽  
BRIAN W. SHELDON ◽  
N. ARLENE KLAPES
Keyword(s):  
Sodium Chlorite ◽  
Escherichia Coli O157 ◽  
Gram Negative Bacteria ◽  
Disodium Edta ◽  
Biocidal Activity ◽  
Salmonella Spp ◽  
Gram Positive ◽  
Gram Negative ◽  
Food Borne ◽  
Salmonella Hadar

The biocidal activity of Salmide®, a sodium chlorite–based oxyhalogen disinfectant, was tested alone or in combination with disodium ethylenediaminetetraacetate (EDTA) or trisodium phosphate (Na3PO4) against nine Salmonella spp. (choleraesuis, enteritidis, hadar, heidelberg, infantis, montevideo, indiana, typhimurium, worthington) and other selected gram-positive (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus) and gram-negative bacteria (Escherichia coli O157:H7, Pseudomonas aeruginosa). After a 15-min exposure to 10 mM Salmide® in distilled deionized water at 37°C, a 2.5-to 6.6-log-cycle reduction in population was observed for all of the 16 strains tested, with the exception of L. monocytogenes ATCC 19111, which appeared to be resistant (&lt;1-log-cycle reduction). When Salmonella hadar was simultaneously exposed to 10 mM Salmide® and 5 or 10 mM disodium EDTA at 37°C for 4 min, the biocidal activity of Salmide® was enhanced twofold (6-log-cycle reduction) compared to that observed with 10 mM Salmide® alone. Treatment with 10 mM disodium EDTA alone produced no significant inactivation &lt;1-log-cycle reduction). Exposure of Salmonella hadar to 55 mM Na3PO4 alone or in combination with 10 mM Salmide® yielded a greater than 6-log-cycle reduction, whereas treatment with 10 mM Salmide® alone yielded a4.1-log-cycle reduction. The presence of protein (as bovine serum albumin) in treatments containing Salmide® significantly reduced the biocidal activity. These results demonstrate that Salmide® has a rapid and concentration-dependent biocidal activity against both gram-positive and gram-negative food-borne bacterial pathogens and spoilage organisms.

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