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1.
Arch Microbiol ; 206(7): 336, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954047

RESUMO

Wild-type Lactococcus lactis strain LAC460 secretes prophage-encoded bacteriocin-like lysin LysL, which kills some Lactococcus strains, but has no lytic effect on the producer. LysL carries two N-terminal enzymatic active domains (EAD), and an unknown C-terminus without homology to known domains. This study aimed to determine whether the C-terminus of LysL carries a cell wall binding domain (CBD) for target specificity of LysL. The C-terminal putative CBD region of LysL was fused with His-tagged green fluorescent protein (HGFPuv). The HGFPuv_CBDlysL gene fusion was ligated into the pASG-IBA4 vector, and introduced into Escherichia coli. The fusion protein was produced and purified with affinity chromatography. To analyse the binding of HGFPuv_CBDLysL to Lactococcus cells, the protein was mixed with LysL-sensitive and LysL-resistant strains, including the LysL-producer LAC460, and the fluorescence of the cells was analysed. As seen in fluorescence microscope, HGFPuv_CBDLysL decorated the cell surface of LysL-sensitive L. cremoris MG1614 with green fluorescence, whereas the resistant L. lactis strains LM0230 and LAC460 remained unfluorescent. The fluorescence plate reader confirmed the microscopy results detecting fluorescence only from four tested LysL-sensitive strains but not from 11 tested LysL-resistant strains. Specific binding of HGFPuv_CBDLysL onto the LysL-sensitive cells but not onto the LysL-resistant strains indicates that the C-terminus of LysL contains specific CBD. In conclusion, this report presents experimental evidence of the presence of a CBD in a lactococcal phage lysin. Moreover, the inability of HGFPuv_CBDLysL to bind to the LysL producer LAC460 may partly explain the host's resistance to its own prophage lysin.


Assuntos
Bacteriocinas , Parede Celular , Lactococcus lactis , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , Parede Celular/metabolismo , Bacteriocinas/metabolismo , Bacteriocinas/genética , Bacteriocinas/química , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Domínios Proteicos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/química , Ligação Proteica
2.
Int J Mol Sci ; 25(13)2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-39000321

RESUMO

In the postantibiotic era, the pathogenicity and resistance of pathogens have increased, leading to an increase in intestinal inflammatory disease. Bacterial infections remain the leading cause of animal mortality. With increasing resistance to antibiotics, there has been a significant decrease in resistance to both inflammation and disease in animals, thus decreasing production efficiency and increasing production costs. These side effects have serious consequences and have detracted from the development of China's pig industry. Microcin C7 (McC7) demonstrates potent antibacterial activity against a broad spectrum of pathogens, stable physicochemical properties, and low toxicity, reducing the likelihood of resistance development. Thus, McC7 has received increasing attention as a potential clinical antibacterial and immunomodulatory agent. McC7 has the potential to serve as a new generation of antibiotic substitutes; however, its commercial applications in the livestock and poultry industry have been limited. In this review, we summarize and discuss the biosynthesis, biochemical properties, structural characteristics, mechanism of action, and immune strategies of McC7. We also describe the ability of McC7 to improve intestinal health. Our aim in this study was to provide a theoretical basis for the application of McC7 as a new feed additive or new veterinary drug in the livestock and poultry breeding industry, thus providing a new strategy for alleviating resistance through feed and mitigating drug resistance. Furthermore, this review provides insight into the new functions and anti-infection mechanisms of bacteriocin peptides and proposes crucial ideas for the research, product development, and application of bacteriocin peptides in different fields, such as the food and medical industries.


Assuntos
Antibacterianos , Bacteriocinas , Bacteriocinas/farmacologia , Bacteriocinas/química , Bacteriocinas/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/uso terapêutico , Animais , Agentes de Imunomodulação/farmacologia , Agentes de Imunomodulação/química , Agentes de Imunomodulação/uso terapêutico , Suínos , Humanos
3.
BMC Genomics ; 25(1): 571, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844835

RESUMO

BACKGROUND: The dramatic increase of antimicrobial resistance in the healthcare realm has become inexorably linked to the abuse of antibiotics over the years. Therefore, this study seeks to identify potential postbiotic metabolites derived from lactic acid bacteria such as Lactiplantibacillus plantarum that could exhibit antimicrobial properties against multi-drug resistant pathogens. RESULTS: In the present work, the genome sequence of Lactiplantibacillus plantarum PA21 consisting of three contigs was assembled to a size of 3,218,706 bp. Phylogenomic analysis and average nucleotide identity (ANI) revealed L. plantarum PA21 is closely related to genomes isolated from diverse niches such as dairy products, food, and animals. Genome mining through the BAGEL4 and antiSMASH database revealed four bacteriocins in a single cluster and four regions of biosynthetic gene clusters responsible for the production of bioactive compounds. The potential probiotic genes indirectly responsible for postbiotic metabolites production were also identified. Additionally, in vitro studies showed that the L. plantarum PA21 cell-free supernatant exhibited antimicrobial activity against all nine methicillin-resistant Staphylococcus aureus (MRSA) and three out of 13 Klebsiella pneumoniae clinical isolates tested. CONCLUSION: Results in this study demonstrates that L. plantarum PA21 postbiotic metabolites is a prolific source of antimicrobials against multi-drug resistant pathogens with potential antimicrobial properties.


Assuntos
Bacteriocinas , Genoma Bacteriano , Staphylococcus aureus Resistente à Meticilina , Filogenia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Bacteriocinas/genética , Antibacterianos/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Família Multigênica , Genômica , Lactobacillus plantarum/genética , Lactobacillus plantarum/metabolismo , Probióticos , Testes de Sensibilidade Microbiana
4.
Microb Cell Fact ; 23(1): 175, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38872163

RESUMO

INTRODUCTION: Bacterial infections and the rising antimicrobial resistance pose a significant threat to public health. Pseudomonas aeruginosa produces bacteriocins like pyocins, especially S-type pyocins, which are promising for biological applications. This research focuses on clinical P. aeruginosa isolates to assess their bacteriocin production, inhibitory spectrum, chemical structure, antibacterial agents, and preservative potential. METHODS: The identification of P. aeruginosa was conducted through both phenotypic and molecular approaches. The inhibitory spectrum and antibacterial potential of the isolates were assessed. The kinetics of antibacterial peptide production were investigated, and the activity of bacteriocin was quantified in arbitrary units (AU ml-1). Physico-chemical characterization of the antibacterial peptides was performed. Molecular weight estimation was carried out using SDS-PAGE. qRT-PCR analysis was employed to validate the expression of the selected candidate gene. RESULT: The antibacterial activity of P. aeruginosa was attributed to the secretion of bacteriocin compounds, which belong to the S-type pyocin family. The use of mitomycin C led to a significant 65.74% increase in pyocin production by these isolates. These S-type pyocins exhibited the ability to inhibit the growth of both Gram-negative (P. mirabilis and P. vulgaris) and Gram-positive (S. aureus, S. epidermidis, E. hirae, S. pyogenes, and S. mutans) bacteria. The molecular weight of S-type pyocin was 66 kDa, and its gene expression was confirmed through qRT-PCR. CONCLUSION: These findings suggest that S-type pyocin hold significant potential as therapeutic agents against pathogenic strains. The Physico-chemical resistance of S-type pyocin underscores its potential for broad applications in the pharmaceutical, hygiene, and food industries.


Assuntos
Antibacterianos , Bacteriocinas , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Antibacterianos/farmacologia , Antibacterianos/biossíntese , Bacteriocinas/biossíntese , Bacteriocinas/farmacologia , Bacteriocinas/metabolismo , Piocinas/metabolismo , Piocinas/farmacologia , Piocinas/biossíntese , Humanos , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/tratamento farmacológico
5.
Gut Microbes ; 16(1): 2369338, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38899682

RESUMO

Gut bacteria are known to produce bacteriocins to inhibit the growth of other bacteria. Consequently, bacteriocins have attracted increased attention as potential microbiome-editing tools. In this study we examine the inhibitory spectrum of 75 class II bacteriocins against 48 representative gut microbiota species. The bacteriocins were heterologously expressed in Escherichia coli and evaluated in vitro, ex vivo and in vivo. In vitro assays revealed 22 bacteriocins to inhibit at least one species and showed selective inhibition patterns against species implicated in certain disorders and diseases. Three bacteriocins were selected for ex vivo assessment on mouse feces. Based on 16S rRNA sequencing of the cultivated feces we showed that the two bacteriocins: Actifencin (#13) and Bacteroidetocin A (#22) selectively inhibited the growth of Lactobacillus and Bacteroides, respectively. The probiotic: E. coli Nissle 1917 was engineered to express these two bacteriocins in mice. However, the selective inhibitory patterns found in the in vitro and ex vivo experiments could not be observed in vivo. Our study describes a methodology for heterologous high throughput bacteriocin expression and screening and elucidates the inhibitory patterns of class II bacteriocins on the gut microbiota.


Assuntos
Antibacterianos , Bacteriocinas , Escherichia coli , Fezes , Microbioma Gastrointestinal , Bacteriocinas/genética , Bacteriocinas/farmacologia , Bacteriocinas/metabolismo , Bacteriocinas/biossíntese , Animais , Camundongos , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Antibacterianos/biossíntese , RNA Ribossômico 16S/genética , Lactobacillus/genética , Lactobacillus/metabolismo , Lactobacillus/efeitos dos fármacos , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Bactérias/classificação , Expressão Gênica
6.
BMC Microbiol ; 24(1): 226, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937695

RESUMO

BACKGROUND: Bacterial antimicrobial resistance poses a severe threat to humanity, necessitating the urgent development of new antibiotics. Recent advances in genome sequencing offer new avenues for antibiotic discovery. Paenibacillus genomes encompass a considerable array of antibiotic biosynthetic gene clusters (BGCs), rendering these species as good candidates for genome-driven novel antibiotic exploration. Nevertheless, BGCs within Paenibacillus genomes have not been extensively studied. RESULTS: We conducted an analysis of 554 Paenibacillus genome sequences, sourced from the National Center for Biotechnology Information database, with a focused investigation involving 89 of these genomes via antiSMASH. Our analysis unearthed a total of 848 BGCs, of which 716 (84.4%) were classified as unknown. From the initial pool of 554 Paenibacillus strains, we selected 26 available in culture collections for an in-depth evaluation. Genomic scrutiny of these selected strains unveiled 255 BGCs, encoding non-ribosomal peptide synthetases, polyketide synthases, and bacteriocins, with 221 (86.7%) classified as unknown. Among these strains, 20 exhibited antimicrobial activity against the gram-positive bacterium Micrococcus luteus, yet only six strains displayed activity against the gram-negative bacterium Escherichia coli. We proceeded to focus on Paenibacillus brasilensis, which featured five new BGCs for further investigation. To facilitate detailed characterization, we constructed a mutant in which a single BGC encoding a novel antibiotic was activated while simultaneously inactivating multiple BGCs using a cytosine base editor (CBE). The novel antibiotic was found to be localized to the cell wall and demonstrated activity against both gram-positive bacteria and fungi. The chemical structure of the new antibiotic was elucidated on the basis of ESIMS, 1D and 2D NMR spectroscopic data. The novel compound, with a molecular weight of 926, was named bracidin. CONCLUSIONS: This study outcome highlights the potential of Paenibacillus species as valuable sources for novel antibiotics. In addition, CBE-mediated dereplication of antibiotics proved to be a rapid and efficient method for characterizing novel antibiotics from Paenibacillus species, suggesting that it will greatly accelerate the genome-based development of new antibiotics.


Assuntos
Antibacterianos , Genoma Bacteriano , Família Multigênica , Paenibacillus , Paenibacillus/genética , Paenibacillus/metabolismo , Antibacterianos/farmacologia , Antibacterianos/biossíntese , Peptídeo Sintases/genética , Policetídeo Sintases/genética , Bacteriocinas/genética , Bacteriocinas/farmacologia , Bacteriocinas/biossíntese , Vias Biossintéticas/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Descoberta de Drogas/métodos
7.
Science ; 384(6701): eado0713, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38870284

RESUMO

Bacteria can repurpose their own bacteriophage viruses (phage) to kill competing bacteria. Phage-derived elements are frequently strain specific in their killing activity, although there is limited evidence that this specificity drives bacterial population dynamics. Here, we identified intact phage and their derived elements in a metapopulation of wild plant-associated Pseudomonas genomes. We discovered that the most abundant viral cluster encodes a phage remnant resembling a phage tail called a tailocin, which bacteria have co-opted to kill bacterial competitors. Each pathogenic Pseudomonas strain carries one of a few distinct tailocin variants that target the variable polysaccharides in the outer membrane of co-occurring pathogenic Pseudomonas strains. Analysis of herbarium samples from the past 170 years revealed that the same tailocin and bacterial receptor variants have persisted in Pseudomonas populations. These results suggest that tailocin genetic diversity can be mined to develop targeted "tailocin cocktails" for microbial control.


Assuntos
Bacteriocinas , Fagos de Pseudomonas , Pseudomonas , Proteínas da Cauda Viral , Antibiose , Membrana Externa Bacteriana/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Variação Genética , Genoma Bacteriano , Polissacarídeos Bacterianos/metabolismo , Pseudomonas/metabolismo , Pseudomonas/virologia , Fagos de Pseudomonas/genética , Fagos de Pseudomonas/metabolismo , Proteínas da Cauda Viral/metabolismo , Proteínas da Cauda Viral/genética , Terapia por Fagos/métodos
8.
Appl Microbiol Biotechnol ; 108(1): 384, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38896287

RESUMO

Bacteriocins have the potential to effectively improve food-borne infections or gastrointestinal diseases and hold promise as viable alternatives to antibiotics. This study aimed to explore the antibacterial activity of three bacteriocins (nisin, enterocin Gr17, and plantaricin RX-8) and their ability to attenuate intestinal barrier dysfunction and inflammatory responses induced by Listeria monocytogenes, respectively. Bacteriocins have shown excellent antibacterial activity against L. monocytogenes without causing any cytotoxicity. Bacteriocins inhibited the adhesion and invasion of L. monocytogenes on Caco-2 cells, lactate dehydrogenase (LDH), trans-epithelial electrical resistance (TEER), and cell migration showed that bacteriocin improved the permeability of Caco-2 cells. These results were attributed to the promotion of tight junction proteins (TJP) assembly, specifically zonula occludens-1 (ZO-1), occludin, and claudin-1. Furthermore, bacteriocins could alleviate inflammation by inhibiting the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) pathways and reducing the secretion of interleukin-6 (IL-6), interleukin-1 ß (IL-1ß) and tumor necrosis factor α (TNF-α). Among three bacteriocins, plantaricin RX-8 showed the best antibacterial activity against L. monocytogenes and the most pronounced protective effect on the intestinal barrier due to its unique structure. Based on our findings, we hypothesized that bacteriocins may inhibit the adhesion and invasion of L. monocytogenes by competing adhesion sites. Moreover, they may further enhance intestinal barrier function by inhibiting the expression of L. monocytogenes virulence factors, increasing the expression of TJP and decreasing the secretion of inflammatory factors. Therefore, bacteriocins will hopefully be an effective alternative to antibiotics, and this study provides valuable insights into food safety concerns. KEY POINTS: • Bacteriocins show excellent antibacterial activity against L. monocytogenes • Bacteriocins improve intestinal barrier damage and inflammatory response • Plantaricin RX-8 has the best protective effect on Caco-2 cells damage.


Assuntos
Antibacterianos , Bacteriocinas , Listeria monocytogenes , Listeria monocytogenes/efeitos dos fármacos , Bacteriocinas/farmacologia , Humanos , Células CACO-2 , Antibacterianos/farmacologia , Inflamação , NF-kappa B/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Proteínas de Junções Íntimas/metabolismo , Citocinas/metabolismo , Listeriose/microbiologia , Listeriose/tratamento farmacológico , Movimento Celular/efeitos dos fármacos
9.
PLoS Biol ; 22(6): e3002616, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38865418

RESUMO

The gastrointestinal tract is densely colonized by a polymicrobial community known as the microbiota which serves as primary line of defence against pathogen invasion. The microbiota can limit gut-luminal pathogen growth at different stages of infection. This can be traced to specific commensal strains exhibiting direct or indirect protective functions. Although these mechanisms hold the potential to develop new approaches to combat enteric pathogens, they remain far from being completely described. In this study, we investigated how a mouse commensal Escherichia coli can outcompete Salmonella enterica serovar Typhimurium (S. Tm). Using a salmonellosis mouse model, we found that the commensal E. coli 8178 strain relies on a trojan horse trap strategy to limit S. Tm expansion in the inflamed gut. Combining mutants and reporter tools, we demonstrated that inflammation triggers the expression of the E. coli 8178 antimicrobial microcin H47 toxin which, when fused to salmochelin siderophores, can specifically alter S. Tm growth. This protective function was compromised upon disruption of the E. coli 8178 tonB-dependent catecholate siderophore uptake system, highlighting a previously unappreciated crosstalk between iron intake and microcin H47 activity. By identifying the genetic determinants mediating S. Tm competition, our work not only provides a better mechanistic understanding of the protective function displayed by members of the gut microbiota but also further expands the general contribution of microcins in bacterial antagonistic relationships. Ultimately, such insights can open new avenues for developing microbiota-based approaches to better control intestinal infections.


Assuntos
Escherichia coli , Inflamação , Salmonella typhimurium , Sideróforos , Animais , Escherichia coli/metabolismo , Escherichia coli/genética , Sideróforos/metabolismo , Camundongos , Salmonella typhimurium/patogenicidade , Salmonella typhimurium/metabolismo , Inflamação/metabolismo , Inflamação/microbiologia , Camundongos Endogâmicos C57BL , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Microbioma Gastrointestinal , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Infecções por Salmonella/microbiologia , Infecções por Salmonella/metabolismo , Feminino , Ferro/metabolismo , Simbiose , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/metabolismo
10.
Int J Mol Sci ; 25(11)2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38891977

RESUMO

Class IIa bacteriocins produced in lactic acid bacteria are short cationic peptides with antimicrobial activity. In the search for new biopreservation agents, class IIa bacteriocins are considered to be the best potential candidates, not only due to their large abundance but also because of their high biological activity and excellent thermal stability. However, regulated by the biosynthetic regulatory system, the natural class IIa bacteriocin yield is low, and the extraction process is complicated. The biotechnological production of class IIa bacteriocins in various cell factories has been attempted to improve this situation. In this review, we focus on the application of biotechnological routes for class IIa bacteriocin production. The drawbacks and improvements in the production of class IIa bacteriocins in various cell factories are discussed. Furthermore, we present the main challenge of class IIa bacteriocins, focusing on increasing their production by constructing suitable cell factories. Recombinant bacteriocins have made considerable progress from inclusion body formation, dissolved form and low antibacterial activity to yield recovery. The development of prospective cell factories for the biotechnological production of bacteriocins is still required, which may facilitate the application of bacteriocins in the food industry.


Assuntos
Bacteriocinas , Biotecnologia , Bacteriocinas/biossíntese , Biotecnologia/métodos , Antibacterianos/biossíntese , Antibacterianos/farmacologia , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/biossíntese , Lactobacillales/metabolismo
11.
BMC Genomics ; 25(1): 575, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849728

RESUMO

BACKGROUND: Staphylococcus shinii appears as an umbrella species encompassing several strains of Staphylococcus pseudoxylosus and Staphylococcus xylosus. Given its phylogenetic closeness to S. xylosus, S. shinii can be found in similar ecological niches, including the microbiota of fermented meats where the species may contribute to colour and flavour development. In addition to these conventional functionalities, a biopreservation potential based on the production of antagonistic compounds may be available. Such potential, however, remains largely unexplored in contrast to the large body of research that is available on the biopreservative properties of lactic acid bacteria. The present study outlines the exploration of the genetic basis of competitiveness and antimicrobial activity of a fermented meat isolate, S. shinii IMDO-S216. To this end, its genome was sequenced, de novo assembled, and annotated. RESULTS: The genome contained a single circular chromosome and eight plasmid replicons. Focus of the genomic exploration was on secondary metabolite biosynthetic gene clusters coding for ribosomally synthesized and posttranslationally modified peptides. One complete cluster was coding for a bacteriocin, namely lactococcin 972; the genes coding for the pre-bacteriocin, the ATP-binding cassette transporter, and the immunity protein were also identified. Five other complete clusters were identified, possibly functioning as competitiveness factors. These clusters were found to be involved in various responses such as membrane fluidity, iron intake from the medium, a quorum sensing system, and decreased sensitivity to antimicrobial peptides and competing microorganisms. The presence of these clusters was equally studied among a selection of multiple Staphylococcus species to assess their prevalence in closely-related organisms. CONCLUSIONS: Such factors possibly translate in an improved adaptation and competitiveness of S. shinii IMDO-S216 which are, in turn, likely to improve its fitness in a fermented meat matrix.


Assuntos
Bacteriocinas , Genoma Bacteriano , Staphylococcus , Staphylococcus/genética , Staphylococcus/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Fermentação , Genômica/métodos , Metabolismo Secundário/genética , Carne/microbiologia , Família Multigênica , Filogenia
12.
Food Res Int ; 188: 114473, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823837

RESUMO

Oral delivery of larger bioactive peptides (>20 amino acids) to the small intestine remains a challenge due to their sensitivity to proteolytic degradation and chemical denaturation during gastrointestinal transit. In this study, we investigated the capacity of crosslinked alginate microcapsules (CLAMs) formed by spray drying to protect Plantaricin EF (PlnEF) (C-EF) in gastric conditions and to dissolve and release PlnEF in the small intestine. PlnEF is an unmodified, two-peptide (PlnE: 33 amino acids; PlnF: 34 amino acids) bacteriocin produced by Lactiplantibacillus plantarum with antimicrobial and gut barrier protective properties. After 2 h incubation in simulated gastric fluid (SGF) (pH 1.5), 43.39 % ± 8.27 % intact PlnEF was liberated from the CLAMs encapsulates, as determined by an antimicrobial activity assay. Transfer of the undissolved fraction to simulated intestinal fluid (SIF) (pH 7) for another 2 h incubation resulted in an additional release of 16.13 % ± 4.33 %. No active PlnEF was found during SGF or sequential SIF incubations when pepsin (2,000 U/ml) was added to the SGF. To test PlnEF release in C-EF contained in a food matrix, C-EF was mixed in peanut butter (PB) (0.15 g C-EF in 1.5 g PB). A total of 12.52 % ± 9.09 % active PlnEF was detected after incubation of PB + C-EF in SGF without pepsin, whereas no activity was found when pepsin was included. Transfer of the remaining PB + C-EF fractions to SIF yielded the recovery of 46.67 % ± 13.09 % and 39.42 % ± 11.53 % active PlnEF in the SIF following exposure to SGF and to SGF with pepsin, respectively. Upon accounting for the undissolved fraction after SIF incubation, PlnEF was fully protected in the CLAMs-PB mixture and there was not a significant reduction in active PlnEF when pepsin was present. These results show that CLAMs alone do not guard PlnEF bacteriocin peptides from gastric conditions, however, mixing them in PB protected against proteolysis and improved intestinal release.


Assuntos
Alginatos , Bacteriocinas , Cápsulas , Alginatos/química , Peptídeos/química , Intestino Delgado/metabolismo , Lactobacillus plantarum/metabolismo , Concentração de Íons de Hidrogênio , Reagentes de Ligações Cruzadas/química , Pepsina A/metabolismo
13.
Appl Microbiol Biotechnol ; 108(1): 370, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861018

RESUMO

Members of the genus Lysinibacillus attract attention for their mosquitocidal, bioremediation, and plant growth-promoting abilities. Despite this interest, comprehensive studies focusing on genomic traits governing plant growth and stress resilience in this genus using whole-genome sequencing are still scarce. Therefore, we sequenced and compared the genomes of three endophytic Lysinibacillus irui strains isolated from Canary Island date palms with the ex-type strain IRB4-01. Overall, the genomes of these strains consist of a circular chromosome with an average size of 4.6 Mb and a GC content of 37.2%. Comparative analysis identified conserved gene clusters within the core genome involved in iron acquisition, phosphate solubilization, indole-3-acetic acid biosynthesis, and volatile compounds. In addition, genome analysis revealed the presence of genes encoding carbohydrate-active enzymes, and proteins that confer resistance to oxidative, osmotic, and salinity stresses. Furthermore, pathways of putative novel bacteriocins were identified in all genomes. This illustrates possible common plant growth-promoting traits shared among all strains of L. irui. Our findings highlight a rich repertoire of genes associated with plant lifestyles, suggesting significant potential for developing inoculants to enhance plant growth and resilience. This study is the first to provide insights into the overall genomic signatures and mechanisms of plant growth promotion and biocontrol in the genus Lysinibacillus. KEY POINTS: • Pioneer study in elucidating plant growth promoting in L. irui through comparative genomics. • Genome mining identified biosynthetic pathways of putative novel bacteriocins. • Future research directions to develop L. irui-based biofertilizers for sustainable agriculture.


Assuntos
Bacillaceae , Genoma Bacteriano , Genômica , Bacillaceae/genética , Bacillaceae/metabolismo , Composição de Bases , Família Multigênica , Arecaceae/microbiologia , Desenvolvimento Vegetal , Sequenciamento Completo do Genoma , Bacteriocinas/genética , Bacteriocinas/metabolismo , Bacteriocinas/biossíntese , Filogenia , Reguladores de Crescimento de Plantas/metabolismo , Ácidos Indolacéticos/metabolismo , Estresse Fisiológico
14.
Vet Res ; 55(1): 66, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38778424

RESUMO

The lasso peptide microcin Y (MccY) effectively inhibits various serotypes of Salmonella in vitro, but the antibacterial effect against S. Pullorum in poultry is still unclear. This study was the first to evaluate the safety and anti-S. Pullorum infection of MccY in specific pathogen-free (SPF) chicks. The safety test showed that the body weight, IgA and IgM levels of serum, and cecal microbiota structure of 3 groups of chicks orally administrated with different doses of MccY (5 mg/kg, 10 mg/kg, 20 mg/kg) for 14 days were not significantly different from those of the control group. Then, the chicks were randomized into 3 groups for the experiment of anti-S. Pullorum infection: (I) negative control group (NC), (II) S. Pullorum-challenged group (SP, 5 × 108 CFU/bird), (III) MccY-treated group (MccY, 20 mg/kg). The results indicated that compared to the SP group, treatment of MccY increased body weight and average daily gain (P < 0.05), reduced S. Pullorum burden in feces, liver, and cecum (P < 0.05), enhanced the thymus, and decreased the spleen and liver index (P < 0.05). Additionally, MccY increased the jejunal villus height, lowered the jejunal and ileal crypt depth (P < 0.05), and upregulated the expression of IL-4, IL-10, ZO-1 in the jejunum and ileum, as well as CLDN-1 in the jejunum (P < 0.05) compared to the SP group. Furthermore, MccY increased probiotic flora (Barnesiella, etc.), while decreasing (P < 0.05) the relative abundance of pathogenic flora (Escherichia and Salmonella, etc.) compared to the SP group.


Assuntos
Bacteriocinas , Galinhas , Microbioma Gastrointestinal , Doenças das Aves Domésticas , Salmonelose Animal , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Bacteriocinas/administração & dosagem , Bacteriocinas/farmacologia , Administração Oral , Salmonella/efeitos dos fármacos , Salmonella/fisiologia , Organismos Livres de Patógenos Específicos , Ração Animal/análise , Antibacterianos/farmacologia , Antibacterianos/administração & dosagem , Distribuição Aleatória , Função da Barreira Intestinal
15.
FEMS Microbiol Ecol ; 100(6)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38806244

RESUMO

Coagulase-negative Staphylococcus (CoNS) species inhibiting Staphylococcus aureus has been described in the skin of atopic dermatitis (AD) patients. This study evaluated whether Staphylococcus spp. from the skin and nares of AD and non-AD children produced antimicrobial substances (AMS). AMS production was screened by an overlay method and tested against NaOH, proteases and 30 indicator strains. Clonality was assessed by pulsed-field gel electrophoresis. Proteinaceous AMS-producers were investigated for autoimmunity by the overlay method and presence of bacteriocin genes by polymerase chain reaction. Two AMS-producers had their genome screened for AMS genes. A methicillin-resistant S. aureus (MRSA) produced proteinaceous AMS that inhibited 51.7% of the staphylococcal indicator strains, and it was active against 60% of the colonies selected from the AD child where it was isolated. On the other hand, 57 (8.8%) CoNS from the nares and skin of AD and non-AD children, most of them S. epidermidis (45.6%), reduced the growth of S. aureus and other CoNS species. Bacteriocin-related genes were detected in the genomes of AMS-producers. AMS production by CoNS inhibited S. aureus and other skin microbiota species from children with AD. Furthermore, an MRSA colonizing a child with AD produced AMS, reinforcing its contribution to dysbiosis and disease severity.


Assuntos
Coagulase , Dermatite Atópica , Staphylococcus aureus Resistente à Meticilina , Microbiota , Pele , Staphylococcus , Dermatite Atópica/microbiologia , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Pele/microbiologia , Criança , Coagulase/genética , Coagulase/metabolismo , Staphylococcus/genética , Bacteriocinas/genética , Antibacterianos/farmacologia , Pré-Escolar , Testes de Sensibilidade Microbiana
16.
Microb Pathog ; 192: 106680, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38729380

RESUMO

Biocontrol of phytopathogens involving the use of bioactive compounds produced by lactic acid bacteria (LAB), is a promising approach to manage many diseases in agriculture. In this study, a lactic acid bacterium designated YB1 was isolated from fermented olives and selected for its antagonistic activity against Verticillium dahliae (V. dahliae) and Agrobacterium tumefaciens (A. tumefaciens). Based on the 16S rRNA gene nucleotide sequence analysis (1565 pb, accession number: OR714267), the new isolate YB1 bacterium was assigned as Leuconostoc mesenteroides YB1 (OR714267) strain. This bacterium produces an active peptide "bacteriocin" called BacYB1, which was purified in four steps. Matrix-assisted lasers desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) based approach was performed to identify and characterize BacYB1. The exact mass was 5470.75 Da, and the analysis of the N-terminal sequence (VTRASGASTPPGTASPFKTL) of BacYB1 revealed no significant similarity to currently available antimicrobial peptides. The BacYB1 displayed a bactericidal mode of action against A. tumefaciens. The potentiel role of BacYB1 to supress the growth of A. tumefaciens was confirmed by live-dead cells viability assay. In pot experiments, the biocontrol efficacy of BacYB1 against V. dahliae wilt on young olive trees was studied. The percentage of dead plants (PDP) and the final mean symptomes severity (FMS) of plants articifialy infected by V. dahliae and treated with the pre-purified peptide BacYB1 (preventive and curative treatments) were significantly inferior to untreated plants. Biochemical analysis of leaves of the plants has shown that polyophenols contents were highly detected in plants infected by V. dahliae and the highest contents of chlorophyl a, b and total chlorophyll were recorded in plants treated with the combination of BacYB1 with the biofertilisant Humivital. BacYB1 presents a promising alternative for the control of Verticillium wilt and crown gall diseases.


Assuntos
Agrobacterium tumefaciens , Bacteriocinas , Leuconostoc mesenteroides , Olea , Doenças das Plantas , RNA Ribossômico 16S , Agrobacterium tumefaciens/metabolismo , Bacteriocinas/farmacologia , Bacteriocinas/metabolismo , Olea/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , RNA Ribossômico 16S/genética , Leuconostoc mesenteroides/metabolismo , Leuconostoc mesenteroides/genética , Agentes de Controle Biológico/metabolismo , Agentes de Controle Biológico/farmacologia , Verticillium/efeitos dos fármacos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Antibiose , Filogenia , Antibacterianos/farmacologia , Antibacterianos/metabolismo
17.
Arch Microbiol ; 206(6): 269, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767708

RESUMO

Bacteriocins are ribosomally synthesized bacterial peptides endowed with antibacterial, antiprotozoal, anticancer and antiviral activities. In the present study, we evaluated the antiviral activities of two bacteriocins, enterocin DD14 (EntDD14) and lacticaseicin 30, against herpes simplex virus type 1 (HSV-1), human coronavirus 229E (HCoV-229E) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Vero, Huh7 and Vero E6 cells, respectively. In addition, the interactions of these bacteriocins with the envelope glycoprotein D of HSV-1 and the receptor binding domains of HCoV-229E and SARS-CoV-2 have been computationally evaluated using protein-protein docking and molecular dynamics simulations. HSV-1 replication in Vero cells was inhibited by EntDD14 and, to a lesser extent, by lacticaseicin 30 added to cells after virus inoculation. EntDD14 and lacticaseicin 30 had no apparent antiviral activity against HCoV-229E; however, EntDD14 was able to inhibit SARS-CoV-2 in Vero E6 cells. Further studies are needed to elucidate the antiviral mechanism of these bacteriocins.


Assuntos
Antivirais , Bacteriocinas , SARS-CoV-2 , Bacteriocinas/farmacologia , Chlorocebus aethiops , Animais , Antivirais/farmacologia , Células Vero , Humanos , SARS-CoV-2/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/fisiologia , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Hidrocarbonetos Aromáticos com Pontes
18.
Microbes Infect ; 26(5-6): 105365, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38777105

RESUMO

Aureocin A53 is a peptide bacteriocin produced by an opportunistic pathogen Staphylococcus aureus strain A53. The spatial structure of aureocin, unlike its amino acid sequence, is similar to the bacteriocin BacSp222, which was recently found to have the ability to induce the inflammatory response in the host cells. The presented research aimed to verify such properties also for aureocin A53. We demonstrated that the synthetic aureocin has slight cytotoxic activity towards murine monocytic-macrophage cells. This molecule was also able to activate murine P388.D1 and RAW 264.7 cells to IFN-γ-dependent production of nitric oxide and to activate production of the pro-inflammatory cytokine - TNF. We also proved that the observed pro-inflammatory activity of the studied bacteriocin is related to the stimulation of the TLR2/TLR6 heterodimer and, consequently, activation of the NF-κB transcription factor. To sum up, A53 is the second bacteriocin described in the literature, showing the pro-inflammatory activity against murine macrophage-like cells.


Assuntos
Bacteriocinas , Macrófagos , Óxido Nítrico , Staphylococcus aureus , Camundongos , Animais , Bacteriocinas/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/imunologia , Staphylococcus aureus/efeitos dos fármacos , Células RAW 264.7 , Óxido Nítrico/metabolismo , NF-kappa B/metabolismo , Receptor 2 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Linhagem Celular , Citocinas/metabolismo , Interferon gama/metabolismo , Inflamação/metabolismo
19.
J Am Chem Soc ; 146(25): 17261-17269, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38759637

RESUMO

Many peptidic natural products, such as lasso peptides, cyclic peptides, and cyclotides, are conformationally constrained and show biological stability, making them attractive scaffolds for drug development. Although many peptides can be synthesized and modified through chemical methods, knot-like lasso peptides such as microcin J25 (MccJ25) and their analogues remain elusive. As the chemical space of MccJ25 analogues accessible through purely biological methods is also limited, we proposed a hybrid approach: flow-based chemical synthesis of non-natural precursor peptides, followed by in vitro transformation with recombinant maturation enzymes, to yield a more diverse array of lasso peptides. Herein, we established the rapid, flow-based synthesis of chemically modified MccJ25 precursor peptides (57 amino acids). Heterologous expression of enzymes McjB and McjC was extensively optimized to improve yields and facilitate the synthesis of multiple analogues of MccJ25, including the incorporation of non-canonical tyrosine and histidine derivatives into the lasso scaffold. Finally, using our chemoenzymatic strategy, we produced a biologically active analogue containing three d-amino acids in the loop region and incorporated backbone N-methylations. Our method provides rapid access to chemically modified lasso peptides that could be used to investigate structure-activity relationships, epitope grafting, and the improvement of therapeutic properties.


Assuntos
Peptídeos , Peptídeos/química , Peptídeos/síntese química , Bacteriocinas
20.
Appl Environ Microbiol ; 90(6): e0016224, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38775468

RESUMO

The emergence of drug-resistant bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), has increased the need to discover novel antimicrobial agents that are effective against these species. Here, we describe the identification and purification of the mutacin BHT-B-like gene locus and bacteriocin peptide from Streptococcus ursoris, which is closely related to Streptococcus ratti; hence, we named this bacteriocin ursoricin. Ursoricin is a cationic, chromosome-encoded peptide that has potent antimicrobial effects against Gram-positive pathogens, including MRSA and VRE, with minimum inhibitory concentrations in the micromolar range. Ursoricin also inhibits the biofilm formation of high biofilm-forming S. aureus. Antibacterial activity was retained after treatment at 100°C for 60 min at a pH range of 3-9 and was partially reduced by treatment with proteinase K for 2 h (63% residual activity). The potent anti-MRSA, anti-VRE, and antibiofilm effects of ursoricin suggest that it is a possible candidate for the treatment of MRSA, VRE, and biofilm-associated infections. IMPORTANCE: The emergence of multidrug-resistant bacteria worldwide has posed a significant public health threat and economic burdens that make the identification and development of novel antimicrobial agents urgent. Bacteriocins are promising new agents that exhibit antibacterial activity against a wide range of human pathogens. In this study, we report that the bacteriocin produced by Streptococcus ursoris showed good antibacterial activity against a wide range of Staphylococcus aureus and enterococcus strains, particularly methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and high biofilm-forming S. aureus. Interestingly, this bacteriocin had a stronger effect on S. aureus than on Staphylococcus epidermidis, which is a major commensal bacterium in human skin; this result is important when considering the disturbance of bacterial flora, especially on the skin, mediated by the application of antibacterial agents.


Assuntos
Antibacterianos , Bacteriocinas , Biofilmes , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Streptococcus , Enterococos Resistentes à Vancomicina , Bacteriocinas/farmacologia , Bacteriocinas/genética , Antibacterianos/farmacologia , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Streptococcus/efeitos dos fármacos
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