scholarly journals Potent Antimicrobial and Antibiofilm Activities of Feleucin-K3 Analogs Modified by α-(4-Pentenyl)-Ala against Multidrug-Resistant Bacteria

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 761
Author(s):  
Xiaomin Guo ◽  
Tiantian Yan ◽  
Jing Rao ◽  
Xin Yue ◽  
Xiong Pei ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cytoplasmic Membrane ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Unnatural Amino Acid ◽  
Cellular Component ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria

The dramatic increase in antimicrobial resistance (AMR) highlights an urgent need to develop new antimicrobial therapies. Thus, antimicrobial peptides (AMPs) have emerged as promising novel antibiotic alternatives. Feleucin-K3 is an amphiphilic α-helical nonapeptide that has powerful antimicrobial activity. In our previous study, it was found that the fourth residue of Feleucin-K3 is important for antimicrobial activity. After α-(4-pentenyl)-Ala was introduced into this position, both the antimicrobial activity and stability were greatly improved. Herein, to improve the limitations of Feleucin-K3, this unnatural amino acid was further introduced into different positions of Feleucin-K3. Among these synthetic Feleucin-K3 analogs, the N-terminal-substituted analog Feleucin-K65 (K65) and C-terminal-substituted analog Feleucin-K70 (K70) had preferable antimicrobial activity. In particular, their antimicrobial activities against multidrug-resistant bacteria were more potent than that of antibiotics. The stabilities of these peptides in salt and serum environments were improved compared with those of Feleucin-K3. In addition, these analogs had low hemolytic activity and AMR. More importantly, they effectively inhibited biofilm formation and exhibited considerable efficacy compared with traditional antibiotics against biofilm infection caused by methicillin-resistant Staphylococcus aureus (MRSA). In antimicrobial mechanism studies, K65 and K70 mainly permeated the outer membrane and depolarized the cytoplasmic membrane, resulting in cellular component leakage and cell death. In summary, analogs K65 and K70 are potential antimicrobial alternatives to solve the antibiotic crisis.

Antimicrobial activity and biofilm inhibition of riparins I, II and III and ultrastructural changes in multidrug-resistant bacteria of medical importance

2020 ◽  
Vol 149 ◽  
pp. 104529
Author(s):  
Jorge Belém Oliveira-Júnior ◽  
Everton Morais da Silva ◽  
Dyana Leal Veras ◽  
Karla Raíza Cardoso Ribeiro ◽  
Catarina Fernandes de Freitas ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Multidrug Resistant ◽  
Ultrastructural Changes ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Biofilm Inhibition ◽  
Medical Importance

scholarly journals High Colonization Rate and Heterogeneity of ESBL- and Carbapenemase-Producing Enterobacteriaceae Isolated from Gull Feces in Lisbon, Portugal

2020 ◽  
Vol 8 (10) ◽  
pp. 1487
Author(s):  
Marta Aires-de-Sousa ◽  
Claudine Fournier ◽  
Elizeth Lopes ◽  
Hermínia de Lencastre ◽  
Patrice Nordmann ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Encoding Genes

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing Enterobacteriaceae for methicillin-resistant Staphylococcus aureus (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing Enterobacteriaceae (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes. Among 24 carbapenemase-producing isolates, there were mainly Klebsiella pneumoniae (50%) and Escherichia coli (33%). OXA-181 was the most common carbapenemase identified (54%), followed by OXA-48 (25%) and KPC-2 (17%). Ten different ESBLs were found among 62 ESBL-producing isolates, mainly being CTX-M-type enzymes (87%). Co-occurrence in single samples of multiple ESBL- and carbapenemase producers belonging to different bacterial species was observed in some cases. Seagulls constitute an important source for spreading multidrug-resistant bacteria in the environment and their gut microbiota a formidable microenvironment for transfer of resistance genes within bacterial species.

scholarly journals Antimicrobial activity of surfactants produced by Bacillus subtilis R14 against multidrug-resistant bacteria

2007 ◽  
Vol 38 (4) ◽  
pp. 704-709 ◽  
Author(s):  
Paulo André Vicente Fernandes ◽  
Isabel Renata de Arruda ◽  
Antônio Fernando Amatto Botelho dos Santos ◽  
Ana Albertina de Araújo ◽  
Ana Maria Souto Maior ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria

scholarly journals The Pomegranate: Effects on Bacteria and Viruses That Influence Human Health

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Amy B. Howell ◽  
Doris H. D'Souza
Keyword(s):  
Antimicrobial Activity ◽  
Foodborne Pathogens ◽  
Clinical Results ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Oral Bacteria ◽  
Resistant Bacteria ◽  
Wide Range

Pomegranates have been known for hundreds of years for their multiple health benefits, including antimicrobial activity. The recent surge in multidrug-resistant bacteria and the possibility of widespread global virus pandemics necessitate the need for additional preventative and therapeutic options to conventional drugs. Research indicates that pomegranates and their extracts may serve as natural alternatives due to their potency against a wide range of bacterial and viral pathogens. Nearly every part of the pomegranate plant has been tested for antimicrobial activities, including the fruit juice, peel, arils, flowers, and bark. Many studies have utilized pomegranate peel with success. There are various phytochemical compounds in pomegranate that have demonstrated antimicrobial activity, but most of the studies have found that ellagic acid and larger hydrolyzable tannins, such as punicalagin, have the highest activities. In some cases the combination of the pomegranate constituents offers the most benefit. The positive clinical results on pomegranate and suppression of oral bacteria are intriguing and worthy of further study. Much of the evidence for pomegranates’ antibacterial and antiviral activities against foodborne pathogens and other infectious disease organisms comes fromin vitrocell-based assays, necessitating further confirmation ofin vivoefficacy through human clinical trials.

scholarly journals Construction of Zinc Oxide into Different Morphological Structures to Be Utilized as Antimicrobial Agent against Multidrug Resistant Bacteria

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
M. F. Elkady ◽  
H. Shokry Hassan ◽  
Elsayed E. Hafez ◽  
Ahmed Fouad
Keyword(s):  
Antimicrobial Activity ◽  
Zinc Oxide ◽  
Surface Area ◽  
High Surface ◽  
Multidrug Resistant ◽  
Annealing Process ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Nano Zno ◽  
Zno Nanotubes

Nano-ZnO has been successfully implemented in particles, rods, and tubes nanostructures via sol-gel and hydrothermal techniques. The variation of the different preparation parameters such as reaction temperature, time, and stabilizer agents was optimized to attain different morphological structures. The influence of the microwave annealing process on ZnO crystallinity, surface area, and morphological structure was monitored using XRD, BET, and SEM techniques, respectively. The antimicrobial activity of zinc oxide produced in nanotubes structure was examined against four different multidrug resistant bacteria: Gram-positive (Staphylococcus aureusandBacillus subtilis) and Gram-negative (Escherichia coliandPseudomonas aeruginosa) strains. The activity of produced nano-ZnO was determined by disc diffusion technique and the results revealed that ZnO nanotubes recorded high activity against the studied strains due to their high surface area equivalent to 17.8 m2/g. The minimum inhibitory concentration (MIC) of ZnO nanotubes showed that the low concentrations of ZnO nanotubes could be a substitution for the commercial antibiotics when approached in suitable formula. Although the annealing process of ZnO improves the degree of material crystallinity, however, it declines its surface area and consequently its antimicrobial activity.

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