RESUMO
Titanium implants are subject to bacterial adhesion and peri-implantitis induction, and biosurfactants bring a new alternative to the fight against infections. This work aimed to produce and characterize the biosurfactant from Bacillus subtilis ATCC 19,659, its anti-adhesion and antimicrobial activity, and cell viability. Anti-adhesion studies were carried out against Streptococcus sanguinis, Staphylococcus aureus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Proteus mirabilis as the minimum inhibitory concentration and the minimum bactericidal concentration. Cell viability was measured against osteoblast and fibroblast cells. The biosurfactant was classified as lipopeptide, with critical micelle concentration at 40 µg mL- 1, and made the titanium surface less hydrophobic. The anti-adhesion effect was observed for Staphylococcus aureus and Streptococcus sanguinis with 54% growth inhibition and presented a minimum inhibitory concentration of 15.7 µg mL- 1 for Streptococcus sanguinis and Aggregatibacter actinomycetemcomitans. The lipopeptide had no cytotoxic effect and demonstrated high potential application against bacterial biofilms.
Assuntos
Aderência Bacteriana , Biofilmes , Implantes Dentários , Lipopeptídeos , Testes de Sensibilidade Microbiana , Titânio , Titânio/farmacologia , Titânio/química , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Aderência Bacteriana/efeitos dos fármacos , Implantes Dentários/microbiologia , Lipopeptídeos/farmacologia , Humanos , Antibacterianos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Bacillus subtilis/efeitos dos fármacos , Porphyromonas gingivalis/efeitos dos fármacos , Porphyromonas gingivalis/fisiologia , Porphyromonas gingivalis/crescimento & desenvolvimento , Aggregatibacter actinomycetemcomitans/efeitos dos fármacos , Propriedades de Superfície , Fibroblastos/efeitos dos fármacos , Fusobacterium nucleatum/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Tensoativos/farmacologiaRESUMO
Bovine mastitis caused by S. aureus has a major economic impact on the dairy sector. With the crucial need for new therapies, anti-virulence strategies have gained attention as alternatives to antibiotics. Here we aimed to identify novel compounds that inhibit the production/activity of hemolysins, a virulence factor of S. aureus associated with mastitis severity. We screened Bacillus strains obtained from diverse sources for compounds showing anti-hemolytic activity. Our results demonstrate that lipopeptides produced by Bacillus spp. completely prevented the hemolytic activity of S. aureus at certain concentrations. Following purification, both iturins, fengycins, and surfactins were able to reduce hemolysis caused by S. aureus, with iturins showing the highest anti-hemolytic activity (up to 76% reduction). The lipopeptides showed an effect at the post-translational level. Molecular docking simulations demonstrated that these compounds can bind to hemolysin, possibly interfering with enzyme action. Lastly, molecular dynamics analysis indicated general stability of important residues for hemolysin activity as well as the presence of hydrogen bonds between iturins and these residues, with longevous interactions. Our data reveals, for the first time, an anti-hemolytic activity of lipopeptides and highlights the potential application of iturins as an anti-virulence therapy to control bovine mastitis caused by S. aureus.
Assuntos
Bacillus , Proteínas Hemolisinas , Hemólise , Lipopeptídeos , Simulação de Acoplamento Molecular , Staphylococcus aureus , Bacillus/metabolismo , Bacillus/química , Staphylococcus aureus/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Animais , Bovinos , Lipopeptídeos/farmacologia , Lipopeptídeos/química , Proteínas Hemolisinas/antagonistas & inibidores , Proteínas Hemolisinas/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Mastite Bovina/microbiologia , Mastite Bovina/tratamento farmacológico , Feminino , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Simulação de Dinâmica MolecularRESUMO
Species from Candida parapsilosis complex are frequently found in neonatal candidemia. The antifungal agents to treat this infection are limited and the occurrence of low in vitro susceptibility to echinocandins such as micafungin has been observed. In this context, the chaperone Hsp90 could be a target to reduce resistance. Thus, the objective of this research was to identify isolates from the C. parapsilosis complex and verify the action of Hsp90 inhibitors associated with micafungin. The fungal identification was based on genetic sequencing and mass spectrometry. Minimal inhibitory concentrations were determined by broth microdilution method according to Clinical Laboratory and Standards Institute. The evaluation of the interaction between micafungin with Hsp90 inhibitors was realized using the checkerboard methodology. According to the polyphasic taxonomy, C. parapsilosis sensu stricto was the most frequently identified, followed by C. orthopsilosis and C. metapsilosis, and one isolate of Lodderomyces elongisporus was identified by genetic sequencing. The Hsp90 inhibitor geladanamycin associated with micafungin showed a synergic effect in 31.25% of the isolates, a better result was observed with radicicol, which shows synergic effect in 56.25% tested yeasts. The results obtained demonstrate that blocking Hsp90 could be effective to reduce antifungal resistance to echinocandins.
Assuntos
Antifúngicos , Candida parapsilosis , Candidemia , Proteínas de Choque Térmico HSP90 , Micafungina , Humanos , Recém-Nascido , Antifúngicos/farmacologia , Benzoquinonas/farmacologia , Candida parapsilosis/efeitos dos fármacos , Candida parapsilosis/isolamento & purificação , Candida parapsilosis/genética , Candidemia/microbiologia , Farmacorresistência Fúngica , Sinergismo Farmacológico , Equinocandinas/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Choque Térmico HSP90/genética , Lactamas Macrocíclicas/farmacologia , Lipopeptídeos/farmacologia , Micafungina/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
Antifungal infections are becoming a major concern to human health due to antimicrobial resistance. Echinocandins have been promising agents against resistant fungal infections, primarily caspofungin, which has a more effective mechanism of action than azoles and polyenes. However, fungi such as Cryptococcus neoformans appear to be inheritably resistant to these drugs, which is concerning due to the high clinical importance of C. neoformans. In this review, we review the history of C. neoformans and the treatments used to treat antifungals over the years, focusing on caspofungin, while highlighting the C. neoformans problem and possible explanations for its inherent resistance.
Caspofungin is a drug used to treat several types of fungal infections. Resistance to caspofungin is a huge problem, especially in those that are immunocompromised. It is important to understand the history of caspofungin discovery, its clinical applications and its mechanism of action, as well as if a new drug target could be used overcome resistance. This review may perform guide new studies combining caspofungin with other drugs and indicate new potential targets for caspofungin.
Assuntos
Antifúngicos , Caspofungina , Criptococose , Cryptococcus neoformans , Farmacorresistência Fúngica , Caspofungina/uso terapêutico , Caspofungina/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Humanos , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Equinocandinas/uso terapêutico , Equinocandinas/farmacologia , Animais , Testes de Sensibilidade Microbiana , Lipopeptídeos/uso terapêutico , Lipopeptídeos/farmacologiaRESUMO
Bacillus sp. has proven to be a goldmine of diverse bioactive lipopeptides, finding wide-range of industrial applications. This review highlights the importance of three major families of lipopeptides (iturin, fengycin, and surfactin) produced by Bacillus sp. and their diverse activities against plant pathogens. This review also emphasizes the role of non-ribosomal peptide synthetases (NRPS) as significant enzymes responsible for synthesizing these lipopeptides, contributing to their peptide diversity. Literature showed that these lipopeptides exhibit potent antifungal activity against various plant pathogens and highlight their specific mechanisms, such as siderophore activity, pore-forming properties, biofilm inhibition, and dislodging activity. The novelty of this review comes from its comprehensive coverage of Bacillus sp. lipopeptides, their production, classification, mechanisms of action, and potential applications in plant protection. It also emphasizes the importance of ongoing research for developing new and enhanced antimicrobial agents. Furthermore, this review article highlights the need for future research to improve the production efficiency of these lipopeptides for commercial applications. It recognizes the potential for these lipopeptides to expand the field of biological pest management for both existing and emerging plant diseases.
Assuntos
Anti-Infecciosos , Bacillus , Bacillus/genética , Anti-Infecciosos/farmacologia , Antifúngicos/farmacologia , Lipopeptídeos/farmacologia , Lipopeptídeos/química , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia , Plantas/microbiologia , Bacillus subtilisRESUMO
(1) Background: Previous studies reported the promising inhibitory effect of cold atmospheric plasma (CAP) on Candida albicans. However, the exact mechanisms of CAP's action on the fungal cell are still poorly understood. This study aims to elucidate the CAP effect on C. albicans cell wall, by evaluating the alterations on its structure and biochemical composition; (2) Methods: C. albicans cells treated with Helium-CAP were analyzed by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) in order to detect morphological, topographic and biochemical changes in the fungal cell wall. Cells treated with caspofungin were also analyzed for comparative purposes; (3) Results: Expressive morphological and topographic changes, such as increased roughness and shape modification, were observed in the cells after CAP exposure. The alterations detected were similar to those observed after the treatment with caspofungin. The main biochemical changes occurred in polysaccharides content, and an overall decrease in glucans and an increase in chitin synthesis were detected; (4) Conclusions: Helium-CAP caused morphological and topographic alterations in C. albicans cells and affected the cell wall polysaccharide content.
Assuntos
Candida albicans , Gases em Plasma , Caspofungina/farmacologia , Antifúngicos/farmacologia , Antifúngicos/análise , Equinocandinas/farmacologia , Hélio , Lipopeptídeos/farmacologia , Gases em Plasma/farmacologia , Parede Celular/químicaRESUMO
Beneficial Bacillus strains can be administered to livestock as probiotics to improve animal health. Cyclic lipopeptides produced by Bacillus such as surfactins may be responsible for some of the beneficial effects due to their anti-inflammatory and immunomodulatory activity. The aim of the present study was to isolate and evaluate the biocompatibility of native Bacillus spp. strains and their surfactin-like lipopeptides in vitro and in vivo to determine their potential to be used on animals. Biocompatibility of endospore suspensions (108 UFC/mL), and different dilutions (1:10; 1:50; 1:100; 1:500, and 1:1000) of Bacillus lipopeptide extracts containing surfactin was tested on Caco-2 cells by microculture tetrazolium-based colorimetric assay. Genotoxicity was tested on BALB/c mice (n = 6) administered 0.2 mL of endospore suspensions by the bone marrow erythrocyte micronuclei assay. All the isolates tested produced between 26.96 and 239.97 µg mL- 1 of surfactin. The lipopeptide extract (LPE) from isolate MFF1.11 demonstrated significant cytotoxicity in vitro. In contrast, LPE from MFF 2.2; MFF 2.7, TL1.11, TL 2.5, and TC12 had no cytotoxic effect (V% > 70%) on Caco-2 cells, not affecting cell viability signifficantly in most treatments. Similarly, none of the endospore suspensions affected cell viability (V% > 80%). Likewise, endospores did not cause genotoxicity on BALB/c mice. This study was elementary as a first step for a new line of research, since it allowed us to choose the safest isolates to keep working on the search of new potentially probiotic strains destined to production animals to improve their performance and health.
Assuntos
Bacillus , Animais , Camundongos , Humanos , Bacillus/metabolismo , Lipopeptídeos/farmacologia , Lipopeptídeos/metabolismo , Células CACO-2 , Suspensões , Peptídeos Cíclicos/toxicidade , Extratos Vegetais , Bacillus subtilis/metabolismoRESUMO
Aedes aegypti and Culex quinquefasciatus are vectors of numerous diseases of worldwide public importance, such as arboviruses and filariasis. The main strategy for controlling these vectors is the use of chemicals, which can induce the appearance of resistant insects. The use of Bacillus thuringiensis (Bt) and Lysinibacillus sphaericus (Ls) with larvicidal activity against arboviral-transmitting insects has been successful in many studies. In contrast, the use and knowledge of peptides with insecticidal activity are so far scarce. In this work, 25 peptides and 5 strains of each bacterial species were prospected individually or together regarding their insecticidal activity. Initially, in vitro assays of cellular cytotoxicity of the peptides against SF21 cells of Spodoptera frugiperda were performed. The peptides Polybia-MPII and pelgipeptin caused 69 and 60% of cell mortality, respectively, at the concentration of 10 µM. Thus, they were evaluated in vivo against second-stage larvae of the two Culicidae. However, in the in vivo bioassays, only pelgipeptin showed larvicidal mortality against both larvae (LC50 6.40 µM against A. aegypti, and LC50 1.22 µM against C. quinquefasciatus). The toxin-producing bacterial strain that showed the lowest LC50 against A. aegypti was Bt S8 (LC50 = 0.71 ng/mL) and against C. quinquefasciatus, it was Ls S260 (LC50 = 2.32 ng/mL). So, the synergistic activity between the association of the bacterial toxins and pelgipeptin was evaluated. A synergic effect of pelgipeptin was observed with Ls strain S260 against C. quinquefasciatus. Our results demonstrate the possibility of synergistic or individual use of both biologically active larvicides against C. quinquefasciatus and A. aegypti.
Assuntos
Anopheles , Bacillaceae , Bacillus thuringiensis , Culex , Inseticidas , Animais , Anopheles/efeitos dos fármacos , Bacillaceae/química , Bacillus thuringiensis/química , Culex/efeitos dos fármacos , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Lipopeptídeos/farmacologia , Mosquitos Vetores , VírusRESUMO
Surfactants are applied in several industrial processes when the modification of interface activity and the stability of colloidal systems are required. Lipopeptides are a class of microbial biosurfactants produced by species of the Bacillus genus. The present study aimed at assembling and analyzing the genome of a new Bacillus vallismortis strain, TIM68, that was shown to produce surfactant lipopeptides. The draft genome was also screened for common virulence factors and antibiotics resistance genes to investigate the strain biosafety. Comparative genomics analyses, i.e., synteny, average nucleotide identity (ANI), and pangenome, were also carried out using strain TIM68 and publicly available B. vallismortis complete and partial genomes. Three peptide synthetase operons were found in TIM68 genome, and they were surfactin A, mojavensin, and a novel plipastatin-like lipopeptide named vallisin. No virulence factors that render pathogenicity to the strain have been identified, but a region of prophage, that may contain unknown pathogenic factors, has been predicted. The pangenome of the species was characterized as closed, with 57% of genes integrating the core genome. The results obtained here on the genetic potential of TIM68 strain should contribute to its exploration in biotechnological applications.
Assuntos
Bacillus , Lipopeptídeos , Lipopeptídeos/farmacologia , Tensoativos/farmacologia , Tensoativos/química , Bacillus/genética , GenômicaRESUMO
We studied a strain of Bacillus isolated from an artisanal tannery in Salta, Argentina. It was identified as Bacillus licheniformis B6 by 16 S phylogenetic analysis and MALDI TOF (GenBank accession code No. KP776730). The synthesis of lipopeptides by B6 and their antibacterial activity against clinical pathogenic strains was analyzed both in the cell-free supernatant (CFS) and in the crude fraction of lipopeptides (LF). Overall, the CFS did not significantly reduce the viability of the studied strains (Staphylococcus aureus 269 and ATCC 43,300, Escherichia coli 4591 and 25,922, Klebsiella sp. 1087 and 1101). However, LF at 9 mg/mL reduced the viability of those pathogenic strains by 2 and 3 log orders compared to those of the control. When the effects of LF and ampicillin were compared, they showed different sensitivity against pathogenic strains. For example, E. coli 4591 was the strain most resistant to ampicillin, requiring 250 mg/mL of antibiotic to achieve the same inhibitory effect as 9 mg/mL of B6 LF. SEM observations of the effect of LF on biofilm formation by E. coli 4591 and Klebsiella sp. 1087 clearly showed that biofilm structures were destabilized, these strains turning into weak biofilm formers. Signals in the CFS and LF corresponding to kurstakin and iturin were identified by MALDI TOF. Interestingly, surfactin was detected, rather than lichenysin, the expected lipopeptide in B. licheniformis species. Signals of bacitracin and fengycins were also found, the latter with a higher number of homologues and relative intensity in the LF than the other lipopeptides. These results show that the lipopeptides synthesized by B. licheniformis B6 have both potential antibacterial and anti-biofilm activity against pathogenic bacteria of health importance.