Antimicrobial potential of bacteriocins: in therapy, agriculture and food preservation.

Currently, the emergence and ongoing dissemination of antimicrobial resistance among bacteria are critical health and economic issue, leading to increased rates of morbidity and mortality related to bacterial infections. Research and development for new antimicrobial agents is currently needed to overcome this problem. Among the different approaches studied, bacteriocins seem to be a promising possibility. These molecules are peptides naturally synthesized by ribosomes, produced by both Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB), which will allow these bacteriocin producers to survive in highly competitive polymicrobial environment. Bacteriocins exhibit antimicrobial activity with variable spectrum depending on the peptide, which may target several bacteria. Already used in some areas such as agro-food, bacteriocins may be considered as interesting candidates for further development as antimicrobial agents used in health contexts, particularly considering the issue of antimicrobial resistance. The aim of this review is to present an updated global report on the biology of bacteriocins produced by GPB and GNB, as well as their antibacterial activity against relevant bacterial pathogens, and especially against multidrug-resistant bacteria.

https://hal.archives-ouvertes.fr/hal-02889866/document

Bacteriocins, Antimicrobial Peptides from Bacterial Origin: Overview of Their Biology and Their Impact against Multidrug-Resistant Bacteria.

Members of the Pseudomonas genus produce diverse secondary metabolites affecting other bacteria, fungi or predating nematodes and protozoa but are also equipped with the capacity to secrete different types of ribosomally encoded toxic peptides and proteins, ranging from small microcins to large tailocins. Studies with the human pathogen Pseudomonas aeruginosa have revealed that effector proteins of type VI secretion systems are part of the antibacterial armamentarium deployed by pseudomonads. A novel class of antibacterial proteins with structural similarity to plant lectins was discovered by studying antagonism among plant-associated Pseudomonas strains. A genomic perspective on pseudomonad bacteriocinogeny shows that the modular architecture of S pyocins of P. aeruginosa is retained in a large diversified group of bacteriocins, most of which target DNA or RNA. Similar modularity is present in as yet poorly characterized Rhs (recombination hot spot) proteins and CDI (contact-dependent inhibition) proteins. Well-delimited domains for receptor recognition or cytotoxicity enable the design of chimeric toxins with novel functionalities, which has been applied successfully for S and R pyocins. Little is known regarding how these antibacterials are released and ultimately reach their targets. Other remaining issues concern the identification of environmental triggers activating these systems and assessment of their ecological impact in niches populated by pseudomonads.

Ribosomally encoded antibacterial proteins and peptides from Pseudomonas

Bacteriocin production is a widespread phenomenon among bacteria. Bacteriocins hold great promise for the treatment of diseases caused by pathogenic bacteria and could be used in the future as alternatives to existing antibiotics. The anti-infective potential of bacteriocins for inhibiting pathogens has been shown in various food matrices including cheese, meat, and vegetables. However, their inhibition of pathogens in vivo remains unclear and needs more investigation, due mainly to difficulties associated with demonstrating their health benefits. Many bacteriocins produced by established or potential probiotic organisms have been evaluated as potential therapeutic agents and interesting findings have been documented in vitro as well as in a few in vivo studies. Some recent in vivo studies point to the efficacy of bacteriocin-based treatments of human and animal infections. While further investigation remains necessary before the possibilities for bacteriocins in clinical practice can be described more fully, this review provides an overview of their potential applications to human and veterinary health.

Anti-infective properties of bacteriocins: an update

The major constituent of the outer membrane of Gram-negative bacteria is lipopolysaccharide (LPS), which is comprised of lipid A, core oligosaccharide, and O antigen, which is a long polysaccharide chain extending into the extracellular environment. Due to the localization of LPS, it is a key molecule on the bacterial cell wall that is recognized by the host to deploy an immune defence in order to neutralize invading pathogens. However, LPS also promotes bacterial survival in a host environment by protecting the bacteria from these threats. This review explores the relationship between the different LPS glycoforms of the opportunistic pathogen Pseudomonas aeruginosa and the ability of this organism to cause persistent infections, especially in the genetic disease cystic fibrosis. We also discuss the role of LPS in facilitating biofilm formation, antibiotic resistance, and how LPS may be targeted by new antimicrobial therapies.

The Role of Pseudomonas aeruginosa Lipopolysaccharide in Bacterial Pathogenesis and Physiology.

In cystic fibrosis patients, chronic lung infection with Pseudomonas aeruginosa and the associated decline in lung function are the major cause of mortality In this report, we show that pyocin S2 displays potent activity against P aeruginosa biofilms, thus representing a potentially improved therapeutic option Using an invertebrate model of P aeruginosa infection, we also show that pyocin S2 is highly active in vivo

https://opus.lib.uts.edu.au/bitstream/10453/114839/1/zac1599.pdf

Activity of Pyocin S2 against Pseudomonas aeruginosa Biofilms

"Die pilgernde Tbrin" is one of a series of novellas in Goethe's last novel, Wilhelm Meisters Wanderjahre.1 It is the first novella actually external to the main action of the novel, and its plot is resolved to a greater extent than most of the other novellas. Despite this seeming closure, however, the novella remains open and ambiguous, due largely to the structure of the Wanderjahre, whose inclusion of the various novellas (some never resolved, some eventually incorporated into the Rahmengeschichte and resolved there) and other modes of discourse (namely, poems and sayings) invites, in fact, demands consideration of many possibilities of answers or solutions. No solution provided by any of the novellas, however "closed," is taken for definitive for all people at all times, but rather each shows the relative strengths and weaknesses of the various attitudes and moral positions; whereas some are preferred over others, still a certain amount of acceptance of all ways of coping is allowed. All of the episodes and novellas of the Wanderjahre invite a comparative interpretation, for the working and reworking of the same or similar issues in their various manifestations requires that the reader take into account the cumulative experience offered by these repetitions with a difference. Goethe "mirrored" one character or situation in another by either varying the material slightly or contrasting the elements sharply. Thus, Hersilie, who translates the story "Die pilgernde T6rin" and gives it to Wilhelm Meister to read, is very nearly reflected in its unnamed main character. The novella "Die pilgernde TIrin" provides a facet of truth, so to speak; it has something, or many things, to say, which alone and out of context may seem onesided and extreme, but restored to the context of the other novellas and other plots can be seen to have a validity as strong as thes others.2 As Hersilie felt inclined to present and interpret the 7Trin's story because it allowed her to explain some of her own beliefs and attitudes, so the sympathetic re der interprets both their stories, each (characters fictional and nonfictional) finding elements of the other's narratives which can serve us as a point of departure for our own worldview. None of these depictions is ultimate or flawless; the novella's heroine is most explicitly called a"fool," and Hersilie herself is self-admittedly a little too schnippisch--flighty, even crazy, and later developments in the novel (namely, in the episodes dealing with Felix's Prachtbiuchlein) show her to be highly confusedpartially unaware and partially misguided-concerning even her own very strong desires. Yet too much emphasis has been placed on the negative interpretation of these women characters, especially of the TErin, as young and foolish, not yet ready or mature enough to become one of the Entsagenden,3 still faulty in their dealings with the world. I want rather to stress the uncommon sympathy Goethe seems to have felt with even some of his "negative" characters, and to show that, even if they

Who’s the fool now? A study of Goethe’s novella "Die pilgernde Törin" from his novel Wilhelm Meisters Wanderjahre

This comparison of Rubezahl tales by Benedikte Naubert and Johann Karl August Musaus shows that each tale presents a system of beliefs implicit in the language and narrative structure, and in the depiction of men and women, Gentile and Jew. Naubert's work represents more truly some of the values of the Enlightenment, in its positive depiction of humane treatment of others and tolerance of class, racial, and sexual difference. He work subverts gender roles, which Musaus's story seeks to enshrine. Thus two important myths of our times are debunked: one, that enlightened thought comes exclusively from the upper echelons of the male educated classes; and two, that the German Volk expressed unanimously these early nationalistic and anti-Semitic sentiments, as Robert Darnton claims.

The Rubezahl Legend in Benedikte Naubert and Johann Karl August Musäus

1This history of this essay is a varied one, and its diverse origins will no doubt still remain visible in the final product I shall allow the fissures to remain in the hope that by bringing a diverse set of questions and problems together in one place, I may allow them mutually to illuminate oneanother Thediscussion issituated largely inthefield ofComparative Literature and World Literature, in Damrosch’s sense of literature read beyond its own borders, with specific reference to the German exilic writer W G Sebald; but the issues raised concern the wider and more urgent sense of a crisis in the humanities, not only in the UK but around the globe The questions addressed here concern the possibility of reading or understanding an ‘Other’, whether by that one means an individual or, by extrapolation, a whole culture or society for whom the named individual is taken as a representative; the argument is pursued first in the context of modern languages and literatures departments under the threat of extinction in the English-speaking world, and then in the more particular context of teaching women’s writing (or by extension any other ‘marginal’ writing) in such departments However, the problems inherent in the attempt to ‘read the other’ are much more general–indeed universal A non-Western, if not precisely postcolonial, context incites an acknowledgement of the seductiveness of self/other binary concepts, especially for those cultures which may be said not to have the same tradition of individualism and selfhood Sebald provides the turning point: the Western European writer who depicts the failure of selfhood so dramatically that he may paradoxically inspire

Laura Martin

Papers

Activity of Pyocin S2 against Pseudomonas aeruginosa Biofilms

Who’s the fool now? A study of Goethe’s novella "Die pilgernde Törin" from his novel Wilhelm Meisters Wanderjahre

The Rubezahl Legend in Benedikte Naubert and Johann Karl August Musäus

Reading the Individual: The Ethics of Narration in the Works of W. G. Sebald as an Example for Comparative Literature

The German enlightenment and romantic Kunstmaerchen as anti-Maerchen