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1.
J Antimicrob Chemother ; 79(1): 112-122, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37966053

RESUMO

BACKGROUND: The synthetic antimicrobial peptide, PaDBS1R1, has been reported as a powerful anti-Klebsiella pneumoniae antimicrobial. However, there is only scarce knowledge about whether K. pneumoniae could develop resistance against PaDBS1R1 and which resistance mechanisms could be involved. OBJECTIVES: Identify via label-free shotgun proteomics the K. pneumoniae resistance mechanisms developed against PaDBS1R1. METHODS: An adaptive laboratory evolution experiment was performed to obtain a PaDBS1R1-resistant K. pneumoniae lineage. Antimicrobial susceptibility was determined through microdilution assay. Modifications in protein abundances between the resistant and sensitive lineages were measured via label-free quantitative shotgun proteomics. Enriched Gene Ontology terms and KEGG pathways were identified through over-representation analysis. Data are available via ProteomeXchange with identifier PXD033020. RESULTS: K. pneumoniae ATCC 13883 parental strain challenged with increased subinhibitory PaDBS1R1 concentrations allowed the PaDBS1R1-resistant K. pneumoniae lineage to emerge. Proteome comparisons between PaDBS1R1-resistant K. pneumoniae and PaDBS1R1-sensitive K. pneumoniae under PaDBS1R1-induced stress conditions enabled the identification and quantification of 1702 proteins, out of which 201 were differentially abundant proteins (DAPs). The profiled DAPs comprised 103 up-regulated proteins (adjusted P value < 0.05, fold change ≥ 2) and 98 down-regulated proteins (adjusted P value < 0.05, fold change ≤ 0.5). The enrichment analysis suggests that PhoPQ-guided LPS modifications and CpxRA-dependent folding machinery could be relevant resistance mechanisms against PaDBS1R1. CONCLUSIONS: Based on experimental evolution and a label-free quantitative shotgun proteomic approach, we showed that K. pneumoniae developed resistance against PaDBS1R1, whereas PhoPQ-guided LPS modifications and CpxRA-dependent folding machinery appear to be relevant resistance mechanisms against PaDBS1R1.


Assuntos
Anti-Infecciosos , Infecções por Klebsiella , Humanos , Antibacterianos/farmacologia , Klebsiella pneumoniae/genética , Peptídeos Antimicrobianos , Proteômica , Lipopolissacarídeos , Anti-Infecciosos/farmacologia , Testes de Sensibilidade Microbiana
2.
Front Microbiol ; 7: 381, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27047486

RESUMO

Bacterial resistance to conventional antibiotics has reached alarming levels, threatening to return to the pre-antibiotic era. Therefore, the search for new antimicrobial compounds that overcome the resistance phenomenon has become a priority. Antimicrobial peptides (AMPs) appear as one of the most promising antibiotic medicines. However, in recent years several AMP-resistance mechanisms have been described. Moreover, the AMP-resistance phenomenon has become more complex due to its association with cross-resistance toward AMP effectors of the host innate immune system. In this context, the use of AMPs as a therapeutic option could be potentially hazardous, since bacteria could develop resistance toward our innate immune system. Here, we review the findings of major studies that deal with the AMP cross-resistance phenomenon.

3.
Front Biosci (Landmark Ed) ; 21(5): 1013-38, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27100488

RESUMO

Bacterial resistance to conventional antibiotics is currently a real problem all over the world, making novel antimicrobial compounds a real research priority. Some of the most promising compounds found to date are antimicrobial peptides (AMPs). The benefits of these drugs include their broad spectrum of activity that affects several microbial processes, making the emergence of resistance less likely. However, bacterial resistance to AMPs is an evolving phenomenon that compromises the therapeutic potential of these compounds. Therefore, it is mandatory to understand bacterial mechanisms of resistance to AMPs in depth, in order to develop more powerful AMPs that overcome the bacterial resistance response.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana , Peptídeos Catiônicos Antimicrobianos/farmacocinética , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/patogenicidade , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Fenômenos Fisiológicos Bacterianos/genética , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Regulação para Baixo , Desenho de Fármacos , Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana/fisiologia , Humanos , Pressão Osmótica , Estabilidade Proteica , Transporte Proteico , Proteólise
4.
Clin Vaccine Immunol ; 16(12): 1829-31, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19726617

RESUMO

In the present work, we evaluated the neutralizing capacity of the antibodies induced by dengue virus type 1 and 2 envelope domain III recombinant proteins in monkeys against strains of different dengue virus type 1 and 2 genotypes. Here we demonstrated that dengue virus type 1 and 2 recombinant proteins induced high titers of neutralizing antibodies against different genotype strains.


Assuntos
Anticorpos Antivirais/imunologia , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Dengue/imunologia , Proteínas Recombinantes/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Reações Cruzadas , Dengue/virologia , Vírus da Dengue/genética , Genótipo , Macaca fascicularis , Testes de Neutralização , Proteínas Recombinantes/metabolismo , Proteínas do Envelope Viral/metabolismo
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