scholarly journals Glycotyping and Specific Separation of Listeria monocytogenes with a Novel Bacteriophage Protein Tool Kit

2020 ◽  
Vol 86 (13) ◽  
Author(s):  
Eric T. Sumrall ◽  
Christian Röhrig ◽  
Mario Hupfeld ◽  
Lavanja Selvakumar ◽  
Jiemin Du ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Receptor Binding ◽  
Food Industry ◽  
Binding Proteins ◽  
New Technologies ◽  
Teichoic Acid ◽  
Complex Nature ◽  
Glycosylation Pattern ◽  
Content Type ◽  
Novel Method

ABSTRACT The Gram-positive pathogen Listeria monocytogenes can be subdivided into at least 12 different serovars, based on the differential expression of a set of somatic and flagellar antigens. Of note, strains belonging to serovars 1/2a, 1/2b, and 4b cause the vast majority of foodborne listeriosis cases and outbreaks. The standard protocol for serovar determination involves an agglutination method using a set of sera containing cell surface-recognizing antibodies. However, this procedure is imperfect in both precision and practicality, due to discrepancies resulting from subjective interpretation. Furthermore, the exact antigenic epitopes remain unclear, due to the preparation of the absorbed sera and the complex nature of polyvalent antibody binding. Here, we present a novel method for quantitative somatic antigen differentiation using a set of recombinant affinity proteins (cell wall-binding domains and receptor-binding proteins) derived from a collection of Listeria bacteriophages. These proteins enable rapid, objective, and precise identification of the different teichoic acid glycopolymer structures, which represent the O-antigens, and allow a near-complete differentiation. This glycotyping approach confirmed serovar designations of over 60 previously characterized Listeria strains. Using select phage receptor-binding proteins coupled to paramagnetic beads, we also demonstrate the ability to specifically isolate serovar 1/2 or 4b cells from a mixed culture. In addition, glycotyping led to the discovery that strains designated serovar 4e actually possess an intermediate 4b-4d teichoic acid glycosylation pattern, underpinning the high discerning power and precision of this novel technique. IMPORTANCE Listeria monocytogenes is a ubiquitous opportunistic pathogen that presents a major concern to the food industry due to its propensity to cause foodborne illness. The Listeria genus contains 15 different serovars, with most of the variance depending on the wall-associated teichoic acid glycopolymers, which confer somatic antigenicity. Strains belonging to serovars 1/2 and 4b cause the vast majority of listeriosis cases and outbreaks, meaning that regulators, as well as the food industry itself, have an interest in rapidly identifying isolates of these particular serovars in food processing environments. Current methods for phenotypic serovar differentiation are slow and lack accuracy, and the food industry could benefit from new technologies allowing serovar-specific isolation. Therefore, the novel method described here for rapid glycotype determination could present a valuable asset to detect and control this bacterium.

scholarly journals Surface Glycopolymers Are Crucial forIn VitroAnti-Wall Teichoic Acid IgG-Mediated Complement Activation and Opsonophagocytosis of Staphylococcus aureus

2015 ◽  
Vol 83 (11) ◽  
pp. 4247-4255 ◽  
Author(s):  
Jong-Ho Lee ◽  
Na-Hyang Kim ◽  
Volker Winstel ◽  
Kenji Kurokawa ◽  
Jesper Larsen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Teichoic Acid ◽  
Complement C3 ◽  
Glycerol Phosphate ◽  
Glycosylation Pattern ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Capsule Production ◽  
Cell Envelopes

ABSTRACTThe cell envelopes of many Gram-positive bacteria contain wall teichoic acids (WTAs).Staphylococcus aureusWTAs are composed of ribitol phosphate (RboP) or glycerol phosphate (GroP) backbones substituted withd-alanine andN-acetyl-d-glucosamine (GlcNAc) orN-acetyl-d-galactosamine (GalNAc). Two WTA glycosyltransferases, TarM and TarS, are responsible for modifying the RboP WTA with α-GlcNAc and β-GlcNAc, respectively. We recently reported that purified human serum anti-WTA IgG specifically recognizes β-GlcNAc of the staphylococcal RboP WTA and then facilitates complement C3 deposition and opsonophagocytosis ofS. aureuslaboratory strains. This prompted us to examine whether anti-WTA IgG can induce C3 deposition on a diverse set of clinicalS. aureusisolates. To this end, we compared anti-WTA IgG-mediated C3 deposition and opsonophagocytosis abilities using 13 different staphylococcal strains. Of note, the majority ofS. aureusstrains tested was recognized by anti-WTA IgG, resulting in C3 deposition and opsonophagocytosis. A minority of strains was not recognized by anti-WTA IgG, which correlated with either extensive capsule production or an alteration in the WTA glycosylation pattern. Our results demonstrate that the presence of WTAs with TarS-mediated glycosylation with β-GlcNAc in clinically isolatedS. aureusstrains is an important factor for induction of anti-WTA IgG-mediated C3 deposition and opsonophagocytosis.

scholarly journals Selection and Characterization of Phage-Resistant Mutant Strains of Listeria monocytogenes Reveal Host Genes Linked to Phage Adsorption

2015 ◽  
Vol 81 (13) ◽  
pp. 4295-4305 ◽  
Author(s):  
Thomas Denes ◽  
Henk C. den Bakker ◽  
Jeffrey I. Tokman ◽  
Claudia Guldimann ◽  
Martin Wiedmann
Keyword(s):  
Listeria Monocytogenes ◽  
Mutant Strain ◽  
Teichoic Acid ◽  
Resistant Mutant ◽  
Single Mutation ◽  
Spontaneous Mutant ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Mutant Strains ◽  
Phage Resistant Mutant

ABSTRACTListeria-infecting phages are readily isolated fromListeria-containing environments, yet little is known about the selective forces they exert on their host. Here, we identified that two virulent phages, LP-048 and LP-125, adsorb to the surface ofListeria monocytogenesstrain 10403S through different mechanisms. We isolated and sequenced, using whole-genome sequencing, 69 spontaneous mutant strains of 10403S that were resistant to either one or both phages. Mutations from 56 phage-resistant mutant strains with only a single mutation mapped to 10 genes representing five loci on the 10403S chromosome. An additional 12 mutant strains showed two mutations, and one mutant strain showed three mutations. Two of the loci, containing seven of the genes, accumulated the majority (n= 64) of the mutations. A representative mutant strain for each of the 10 genes was shown to resist phage infection through mechanisms of adsorption inhibition. Complementation of mutant strains with the associated wild-type allele was able to rescue phage susceptibility for 6 out of the 10 representative mutant strains. Wheat germ agglutinin, which specifically binds toN-acetylglucosamine, bound to 10403S and mutant strains resistant to LP-048 but did not bind to mutant strains resistant to only LP-125. We conclude that mutant strains resistant to only LP-125 lack terminalN-acetylglucosamine in their wall teichoic acid (WTA), whereas mutant strains resistant to both phages have disruptive mutations in their rhamnose biosynthesis operon but still possessN-acetylglucosamine in their WTA.

scholarly journals Vurgulu Elektrik Alan (PEF) Tekniğinin Et ve Su Ürünlerinin İşlenmesinde Kullanımı

2020 ◽  
Vol 8 (10) ◽  
pp. 2202-2213
Author(s):  
Berkay Kopuk ◽  
Recep Güneş ◽  
Harun Uran
Keyword(s):  
Food Industry ◽  
Production Efficiency ◽  
New Technologies ◽  
Processing Technologies ◽  
Comprehensive Review ◽  
Solid Foods ◽  
Positive Effects ◽  
Novel Method ◽  
Review Study ◽  
Thermal Techniques

In the food industry, using of new preservation and processing technologies, which may be an alternative to traditional methods, is becoming increasingly important. These novel and particularly non-thermal techniques have very important advantages such as enhancing food safety, reducing quality losses, and increasing production efficiency. One of these new technologies, Pulsed electric field (PEF) technique, stands out as a novel method that has been emphasized in recent years. It is used for different purposes in both liquid and solid foods, also various studies are carried out for the optimization. On the other hand, recently, there are several studies using PEF technique in meats and seafoods for the preservation purposes, as well as other positive effects (improving the functional properties of the product, accelerating processes such as drying, curing and freezing). In this regard, detailed information about the purposes for which PEF technique can be used in meats and seafoods has been tried to be given in this comprehensive review study.

scholarly journals Spodoptera frugiperda (J. E. Smith) Aminopeptidase N1 Is a Functional Receptor of the Bacillus thuringiensis Cry1Ca Toxin

2018 ◽  
Vol 84 (17) ◽  
Author(s):  
Isabel Gómez ◽  
Daniel E. Rodríguez-Chamorro ◽  
Gabriela Flores-Ramírez ◽  
Ricardo Grande ◽  
Fernando Zúñiga ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Receptor Binding ◽  
Spodoptera Frugiperda ◽  
Binding Proteins ◽  
Membrane Vesicles ◽  
Amino Acid Residues ◽  
Content Type ◽  
Different Populations ◽  
Domain Iii ◽  
Functional Receptor

ABSTRACT Bacillus thuringiensis Cry1Ca is toxic to different Spodoptera species. The aims of this work were to identify the Cry1Ca-binding proteins in S. frugiperda, to provide evidence on their participation in toxicity, and to identify the Cry1Ca amino acid residues involved in receptor binding. Pulldown assays using Spodoptera frugiperda brush border membrane vesicles (BBMV) identified aminopeptidase N (APN), APN1, and APN2 isoforms as Cry1Ca-binding proteins. Cry1Ca alanine substitutions in all residues of domain III β16 were characterized. Two β16 nontoxic mutants (V505A and S506A) showed a correlative defect on binding to the recombinant S. frugiperda APN1 (SfAPN1). Finally, silencing the expression of APN1 transcript, by double-stranded RNA (dsRNA) feeding, showed that silenced larvae are more tolerant of the Cry1Ca toxin, which induced less than 40% mortality in silenced larvae whereas nonsilenced larvae had 100% mortality. Overall, our results show that Cry1Ca relies on APN1 binding through domain III β16 to impart toxicity to S. frugiperda. IMPORTANCE Bacillus thuringiensis Cry toxins rely on receptor binding to exert toxicity. Cry1Ca is toxic to different populations of S. frugiperda, a major corn pest in America. Nevertheless, the S. frugiperda midgut proteins that are involved in Cry1Ca toxicity have not been identified. Here we identified aminopeptidase N1 (APN1) as a functional receptor of Cry1Ca. Moreover, we showed that Cry1Ca domain III β16 is involved in APN1 binding. These results give insights on potential target sites for improving Cry1Ca toxicity to S. frugiperda.

The importance of trust for electronic commerce satisfaction: an entrepreneurial perspective

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Farid Shirazi ◽  
Nawal Abdalla Adam ◽  
Mohana Shanmugam ◽  
Carsten D. Schultz
Keyword(s):  
Social Media ◽  
Electronic Commerce ◽  
Food Industry ◽  
New Technologies ◽  
Partial Least Square ◽  
Mediating Effect ◽  
Equation Modeling ◽  
Social Commerce ◽  
Content Type

PurposeSocial commerce has seen a prosperous growth following the rise of social media, in particular, social networking sites have established novel ways to communicate and transact between firms and people. The rise of new technologies has also directed to changes in how entrepreneurs convey their business. Despite intensive social commerce research, the challenges of social commerce for entrepreneurs have attracted less attention and especially neglected the role of trust and satisfaction in electronic commerce.Design/methodology/approachThis research use a survey to collect data. The authors use structural equation modeling-partial least square (SEM-PLS) to analysis the data. This quantitative research provides new insights in the food industry.FindingsThis research thus provides insights into social commerce by analyzing the role of trust in the relationship between customers' social media activities and customers' satisfaction. The present study finds a mediating effect of trust in developing satisfaction. Social media activities facilitate a positive level of trust that in turn creates a satisfying environment for customers in social commerce. The research provides theoretical and practical implications at the end of the study.Originality/valueThe findings provide good knowledge for the food industry to stay connected with customers and develop their satisfaction.

scholarly journals Wall Teichoic Acids Restrict Access of Bacteriophage Endolysin Ply118, Ply511, and PlyP40 Cell Wall Binding Domains to the Listeria monocytogenes Peptidoglycan

2012 ◽  
Vol 194 (23) ◽  
pp. 6498-6506 ◽  
Author(s):  
Marcel R. Eugster ◽  
Martin J. Loessner
Keyword(s):  
Cell Wall ◽  
Listeria Monocytogenes ◽  
Teichoic Acid ◽  
Single Copy ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Binding Domains ◽  
Cell Wall Binding ◽  
Wall Teichoic Acids

ABSTRACTThe C-terminal cell wall binding domains (CBDs) of phage endolysins direct the enzymes to their binding ligands on the bacterial cell wall with high affinity and specificity. TheListeria monocytogenesPly118, Ply511, and PlyP40 endolysins feature related CBDs which recognize the directly cross-linked peptidoglycan backbone structure ofListeria. However, decoration with fluorescently labeled CBDs primarily occurs at the poles and septal regions of the rod-shaped cells. To elucidate the potential role of secondary cell wall-associated carbohydrates such as the abundant wall teichoic acid (WTA) on this phenomenon, we investigated CBD binding usingL. monocytogenesserovar 1/2 and 4 cells deficient in WTA. Mutants were obtained by deletion of two redundanttagOhomologues, whose products catalyze synthesis of the WTA linkage unit. While inactivation of eithertagO1(EGDelmo0959) ortagO2(EGDelmo2519) alone did not affect WTA content, removal of both alleles following conditional complementation yielded WTA-deficientListeriacells. Substitution oftagOfrom an isopropyl-β-d-thiogalactopyranoside-inducible single-copy integration vector restored the original phenotype. Although WTA-deficient cells are viable, they featured severe growth inhibition and an unusual coccoid morphology. In contrast to CBDs from otherListeriaphage endolysins which directly utilize WTA as binding ligand, the data presented here show that WTAs are not required for attachment of CBD118, CBD511, and CBDP40. Instead, lack of the cell wall polymers enables unrestricted spatial access of CBDs to the cell wall surface, indicating that the abundant WTA can negatively regulate sidewall localization of the cell wall binding domains.

scholarly journals Mobile Elements Harboring Heavy Metal and Bacitracin Resistance Genes Are Common among Listeria monocytogenes Strains Persisting on Dairy Farms

mSphere ◽  
2021 ◽  
Author(s):  
Hanna Castro ◽  
François P. Douillard ◽  
Hannu Korkeala ◽  
Miia Lindström
Keyword(s):  
Heavy Metal ◽  
Listeria Monocytogenes ◽  
Resistance Genes ◽  
Food Industry ◽  
Raw Materials ◽  
Dairy Farms ◽  
Mobile Elements ◽  
Content Type ◽  
Effective Strategies

Animal-derived raw materials are an important source of L. monocytogenes in the food industry. Knowledge of the factors contributing to the pathogen’s transmission and persistence on farms are essential for designing effective strategies against the spread of the pathogen from farm to fork.

scholarly journals The Presence of Two Receptor-Binding Proteins Contributes to the Wide Host Range of Staphylococcal Twort-Like Phages

2016 ◽  
Vol 82 (19) ◽  
pp. 5763-5774 ◽  
Author(s):  
Ippei Takeuchi ◽  
Keita Osada ◽  
Aa Haeruman Azam ◽  
Hiroaki Asakawa ◽  
Kazuhiko Miyanaga ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Host Range ◽  
Receptor Binding ◽  
Polyclonal Antibody ◽  
Binding Proteins ◽  
Host Recognition ◽  
Resistant Bacteria ◽  
Tail Fiber ◽  
Content Type ◽  
Wide Host Range

ABSTRACTThanks to their wide host range and virulence, staphylococcal bacteriophages (phages) belonging to the genusTwortlikevirus(staphylococcal Twort-like phages) are regarded as ideal candidates for clinical application forStaphylococcus aureusinfections due to the emergence of antibiotic-resistant bacteria of this species. To increase the usability of these phages, it is necessary to understand the mechanism underlying host recognition, especially the receptor-binding proteins (RBPs) that determine host range. In this study, we found that the staphylococcal Twort-like phage ΦSA012 possesses at least two RBPs. Genomic analysis of five mutant phages of ΦSA012 revealed point mutations inorf103, in a region unique to staphylococcal Twort-like phages. Phages harboring mutated ORF103 could not infectS. aureusstrains in which wall teichoic acids (WTAs) are glycosylated with α-N-acetylglucosamine (α-GlcNAc). A polyclonal antibody against ORF103 also inhibited infection by ΦSA012 in the presence of α-GlcNAc, suggesting that ORF103 binds to α-GlcNAc. In contrast, a polyclonal antibody against ORF105, a short tail fiber component previously shown to be an RBP, inhibited phage infection irrespective of the presence of α-GlcNAc. Immunoelectron microscopy indicated that ORF103 is a tail fiber component localized at the bottom of the baseplate. From these results, we conclude that ORF103 binds α-GlcNAc in WTAs, whereas ORF105, the primary RBP, is likely to bind the WTA backbone. These findings provide insight into the infection mechanism of staphylococcal Twort-like phages.IMPORTANCEStaphylococcusphages belonging to the genusTwortlikevirus(called staphylococcal Twort-like phages) are considered promising agents for control ofStaphylococcus aureusdue to their wide host range and highly lytic capabilities. Although staphylococcal Twort-like phages have been studied widely for therapeutic purposes, the host recognition process of staphylococcal Twort-like phages remains unclear. This work provides new findings about the mechanisms of host recognition of the staphylococcal Twort-like phage ΦSA012. The details of the host recognition mechanism of ΦSA012 will allow us to analyze the mechanisms of infection and expand the utility of staphylococcal Twort-like phages for the control ofS. aureus.

scholarly journals Genomic Differences between Listeria monocytogenes EGDe Isolates Reveal Crucial Roles for SigB and Wall Rhamnosylation in Biofilm Formation

2020 ◽  
Vol 202 (7) ◽  
Author(s):  
Chih-Yu Hsu ◽  
Lynne Cairns ◽  
Laura Hobley ◽  
James Abbott ◽  
Conor O’Byrne ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Teichoic Acid ◽  
Growth Conditions ◽  
Nucleotide Polymorphisms ◽  
Wall Teichoic Acid ◽  
Content Type ◽  
Upstream Regulator ◽  
Fundamental Information ◽  
New Treatments

ABSTRACT Listeria monocytogenes is a Gram-positive firmicute that causes foodborne infections, in part due to its ability to use multiple strategies, including biofilm formation, to survive adverse growth conditions. As a potential way to screen for genes required for biofilm formation, we harnessed the ability of bacteria to accumulate mutations in the genome over time, diverging the properties of seemingly identical strains. By sequencing the genomes of four laboratory reference strains of the commonly used L. monocytogenes EGDe, we showed that each isolate contains single nucleotide polymorphisms (SNPs) compared with the reference genome. We discovered that two SNPs, contained in two independent genes within one of the isolates, impacted biofilm formation. Using bacterial genetics and phenotypic assays, we confirmed that rsbU and rmlA influence biofilm formation. RsbU is the upstream regulator of the alternative sigma factor SigB, and mutation of either rsbU or sigB increased biofilm formation. In contrast, deletion of rmlA, which encodes the first enzyme for TDP-l-rhamnose biosynthesis, resulted in a reduction in the amount of biofilm formed. Further analysis of biofilm formation in a strain that still produces TDP-l-rhamnose but which cannot decorate the wall teichoic acid with rhamnose (rmlT mutant) showed that it is the decorated wall teichoic acid that is required for adhesion of the cells to surfaces. Together, these data uncover novel routes by which biofilm formation by L. monocytogenes can be impacted. IMPORTANCE Biofilms are an important mode of growth in many settings. Here, we looked at small differences in the genomes of the bacterium Listeria monocytogenes isolate EGDe and used them to find out how biofilms form. This important fundamental information may help new treatments to be developed and also highlights the fact that isolates of the same identity often diverge.

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