China
Africa
Explore chapters and articles related to this topic
Prospective Therapeutic Applications of Bacteriocins as Anticancer Agents
Published in Ananda M. Chakrabarty, Arsénio M. Fialho, Microbial Infections and Cancer Therapy, 2019
Lígia F. Coelho, Nuno Bernardes, Arsénio M. Fialho
Class II bacteriocins are heat-stable peptides with a molecular mass usually not higher than 10 kDa. In contrast with lantibiotics, these bacteriocins have no lanthionine content or other post-translational modification beyond the removal of the signal peptide and the formation of a conserved N-terminal disulfide bridge. They have an amphiphilic helical structure, which allows them to enter into the membrane of the target cell, leading to depolarization and necrosis. Indeed, the different biophysical structures that ACPs are reported to assume are crucial for cancer cell membranes’ attachment and pore formation [9]. Class II bacteriocins have at least three subclasses (a, b, and c), and most standard class II bacteriocins with anticancer properties are pediocins and plantaricins. However, the growing interest in LAB bacteriocins for therapeutic purposes has required new classifications for emerging bacteriocins. As examples, new peptides such as the template peptides of KL15 have been proposed to be included in a new branch called class IId bacteriocins [10, 13], and other literature also refers to a subclass IIe [3].
Beneficial Lactic Acid Bacteria
Published in K. Balamurugan, U. Prithika, Pocket Guide to Bacterial Infections, 2019
Majority of the genes encoding bacteriocins are clustered in operons lying in the bacterial chromosome, plasmids, or transposons. The expression needs at least two genes: gene directly encoding bacteriocin and gene of immunity protein providing protection from the compound (some operons of class II bacteriocins). In most cases, the production is also dependent on specific export machinery and regulation factors. The operons of lantibiotics are more complex because they require additional enzymes for posttranslational modifications. Bacteriocins are mainly synthesized as propeptides with leader sequences (Dimov et al. 2005). Some bacteriocins possess more complex structure consisting of several peptides (Stephens et al. 1998).
In vitro activity of the antimicrobial peptide AP7121 against the human methicillin-resistant biofilm producers Staphylococcus aureus and Staphylococcus epidermidis
Published in Biofouling, 2020
Gastón Delpech, Mónica Ceci, Sabina Lissarrague, Leonardo García Allende, Beatriz Baldaccini, Mónica Sparo
This study showed that enterocin APT7121, a class II bacteriocin, prevents the colonization of the biofilm-producer S. aureus on an inert surface. SEM analysis showed significant differences between non-treated (control) and treated (experimental) glass with AP7121. In the control glasses, homogeneous thick layers of S. aureus cells were observed, whilst in the experimental glasses, cell patches as well as isolated groups of bacteria were detected. Similar results were found, through SEM assessment, for sonorensin, a heterocycloanthracin bacteriocin produced by the marine bacterium Bacillus sonorensis MT93, when it was assayed as an anti-biofilm agent for the biological preservation of food (Chopra et al. 2015). Also, SEM studies performed by Al Atya et al. (2016) showed a lower number of adherent MRSA cells on a glass device after using enterocin DDC28 in combination with erythromycin.