scholarly journals Minibactenecins ChBac7.Nα and ChBac7. Nβ - Antimicrobial Peptides from Leukocytes of the Goat Capra hircus.

Acta Naturae ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 136-146 ◽  
Author(s):  
O. V. Shamova ◽  
D. S. Orlov ◽  
M. S. Zharkova ◽  
S. V. Balandin ◽  
E. V. Yamschikova ◽  
...  

Antimicrobial peptides (AMPs) of neutrophils play an important role in the animal and human host defenses. We have isolated two AMPs (average molecular masses of 2895.5 and 2739.3 Da), with potent antimicrobial activity from neutrophils of the domestic goat (Capra hircus). A structural analysis of the obtained peptides revealed that they encompass N-terminal fragments (1-21 and 1-22) of the proline-rich peptide bactenecin 7.5. The primary structure of caprine bactenecin 7.5 had been previously deduced from the nucleotide sequence, but the corresponding protein had not been isolated from leukocytes until now. The obtained caprine AMPs were designated as mini-batenecins (mini-ChBac7.5N and mini-ChBac7.5N), analogously to the reported C-terminal fragment of the ovine bactenecin 7.5 named Bac7.5mini [Anderson, Yu, 2003]. Caprine mini-ChBac7.5N and mini-ChBac7.5N exhibit significant antimicrobial activity against Gram-negative bacteria, including drug-resistant strains of Pseudomonas aeruginosa, Klebsiella spp., Acinetobacter baumannii at a range of concentrations of 0.5-4 M, as well as against some species of Gram-positive bacteria (Listeria monocytogenes EGD, Micrococcus luteus). The eptides demonstrate lipopolysaccharide-binding activity. Similarly to most proline-rich AMPs, caprine peptides inactivate bacteria without appreciable damage of their membranes. Mini-ChBac7.5N and mini-ChBac7.5N have no hemolytic effect on human red blood cells and are nontoxic to various cultured human cells. Therefore, they might be considered as promising templates for the development of novel antibiotic pharmaceuticals. Isolation of highly active fragments of the antimicrobial peptide from goat neutrophils supports the hypothesis that fragmentation of cathelicidin-related AMPs is an important process that results in the generation of potent effector molecules, which are in some cases more active than full-size AMPs. These truncated AMPs may play a crucial role in host defense reactions.

2021 ◽  
Author(s):  
Patricia Yumi Hayashida ◽  
Pedro Ismael Silva Junior

Background: Snails and slugs were used as a treatment for many health problems therefore ancient times. Since the antimicrobial resistance became a major global thread, antimicrobial peptides have been considered as a potential source for development of new drugs, especially for drug-resistant bacteria. Nowadays reports confirm that the mucous secretions have antimicrobial, antiviral and antifungal properties. Methods: The present study has the objective to characterize and evaluate antimicrobial peptides of Limacus flavus mucus. The mucus was obtained by thermal shock and submitted to RP-HPLC. Fractions were used to perform the antimicrobial activity and hemolytic assays, electrophoresis (SDS-Page Gel) and submitted to mass spectrometry (LC-MS / MS). Identification and characterization was performed by PeaksX+ software. The physicochemical parameters were evaluated with bioinformatics tools, which predicted water solubility, iso-electric point, charge net and its primary structure. Results: Three fractions were isolated from the mucus of L. flavus and presented antifungal and antibacterial activity. The mucus showed greater inhibition for filamentous fungi (Aspergillus niger), yeast (Cryptococcus neoformans), Gram positive bacteria (Bacillus subtilis, Micrococcus luteus) and Gram negative bacteria (Enterobacter cloacae). These fractions also did not show hemolytic activity for human blood cells (erythrocytes). Fractions sequences were identified and presents Mw <3kDa, WLGH, DLQW, YLRW, respectively. Conclusion: This study revealed three antimicrobial peptides of L. flavus mucus with a wide range of antimicrobial activity and its physic-chemical characterization. Keywords: Limacus flavus, mucus, slug, antimicrobial peptide, bioactive molecules, resistance, microorganisms.


2020 ◽  
Vol 65 (4) ◽  
pp. 244-250
Author(s):  
Elena Vladimirovna Detysheva ◽  
N. K. Fursova ◽  
S. A. Korovkin

The study is devoted to the study of the antimicrobial activity of the antioxidant dioxidin and the complex dioxin-containing preparation Nosolin-ultra, nasal drops against planktonic and biofilm cultures of pathogens of ENT infections, the dynamics of the formation of microbial resistance to dioxidine. 11 reference strains and 9 clinical strains of microorganisms were used in the study: Streptococcus spp., Staphylococcus spp., Micrococcus luteus, Haemophilus influenzae, Acinetobacter pittii, Klebsiella pneumoniae, Moraxella catarrhalis, Pseudomonas aeruginosa. The antimicrobial activity of preparations against planktonic cultures was determined by serial dilution in broth and spot method on solid nutrient media, against biofilms by the applicator method. The dynamics of dioxidine resistance formation was studied by passaging cultures in a liquid nutrient medium with increasing concentrations of antiseptic. Based on the study, it was found that Dioxidin showed antimicrobial activity against plankton cells of all strains (MBC=0.08-5 mg/ml), except S. pyogenes SN345 (MBC>5 mg/ml), inhibited the growth of formed biofilms (MBC=0.08-2.5 mg/ml) of all strains except S. pyogenes SN345 (MBC>5 mg/ml). The drug «Nosolin-ultra, nasal drops» was highly active against plankton cells (MBC=0.04-0.63 mg/ml) and biofilms (MBC=0.02-0.31 mg/ml) of gram-negative bacteria, except A. pittii (MBC>2.5 mg/ml), less active against plankton cells (MBC=1.25-2.5 mg/ml) and biofilms (MBC=0.02-0.31 mg/ml) of gram-positive bacteria and C. albicans. One strain (S. aureus) formed a variant resistant to dioxidine at a concentration of 20 mg/ml, which exceeded the concentration of dioxidine in the complex preparation; other strains (P. aeruginosa, K. pneumoniae, C. albicans) did not form such variants. The data obtained indicate that the drug «Nosolin-ultra, nasal drops» can be effectively used against most pathogens of ENT infections. It is worth noting that with prolonged use of the drug for some types of ENT pathogens in the future, a slight decrease in effectiveness may be noted.


Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.


2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Junpeng Li ◽  
Shuping Hu ◽  
Wei Jian ◽  
Chengjian Xie ◽  
Xingyong Yang

AbstractAntimicrobial peptides (AMPs) are a class of short, usually positively charged polypeptides that exist in humans, animals, and plants. Considering the increasing number of drug-resistant pathogens, the antimicrobial activity of AMPs has attracted much attention. AMPs with broad-spectrum antimicrobial activity against many gram-positive bacteria, gram-negative bacteria, and fungi are an important defensive barrier against pathogens for many organisms. With continuing research, many other physiological functions of plant AMPs have been found in addition to their antimicrobial roles, such as regulating plant growth and development and treating many diseases with high efficacy. The potential applicability of plant AMPs in agricultural production, as food additives and disease treatments, has garnered much interest. This review focuses on the types of plant AMPs, their mechanisms of action, the parameters affecting the antimicrobial activities of AMPs, and their potential applications in agricultural production, the food industry, breeding industry, and medical field.


2021 ◽  
Vol 11 (12) ◽  
pp. 5352
Author(s):  
Ana Margarida Pereira ◽  
Diana Gomes ◽  
André da Costa ◽  
Simoni Campos Dias ◽  
Margarida Casal ◽  
...  

Antibacterial resistance is a major worldwide threat due to the increasing number of infections caused by antibiotic-resistant bacteria with medical devices being a major source of these infections. This suggests the need for new antimicrobial biomaterial designs able to withstand the increasing pressure of antimicrobial resistance. Recombinant protein polymers (rPPs) are an emerging class of nature-inspired biopolymers with unique chemical, physical and biological properties. These polymers can be functionalized with antimicrobial molecules utilizing recombinant DNA technology and then produced in microbial cell factories. In this work, we report the functionalization of rPBPs based on elastin and silk-elastin with different antimicrobial peptides (AMPs). These polymers were produced in Escherichia coli, successfully purified by employing non-chromatographic processes, and used for the production of free-standing films. The antimicrobial activity of the materials was evaluated against Gram-positive and Gram-negative bacteria, and results showed that the polymers demonstrated antimicrobial activity, pointing out the potential of these biopolymers for the development of new advanced antimicrobial materials.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Ali Salama ◽  
Ammar Almaaytah ◽  
Rula M. Darwish

(1) Background: Antimicrobial resistance represents an urgent health dilemma facing the global human population. The development of novel antimicrobial agents is needed to face the rising number of resistant bacteria. Ultrashort antimicrobial peptides (USAMPs) are considered promising antimicrobial agents that meet the required criteria of novel antimicrobial drug development. (2) Methods: Alapropoginine was rationally designed by incorporating arginine (R), biphenylalanine (B), and naproxen to create an ultrashort hexapeptide. The antimicrobial activity of alapropoginine was evaluated against different strains of bacteria. The hemolytic activity of alapropoginine was also investigated against human erythrocytes. Finally, synergistic studies with antibiotics were performed using the checkerboard technique and the determination of the fractional inhibitory index. (3) Results: Alapropoginine displayed potent antimicrobial activities against reference and multi-drug-resistant bacteria with MIC values of as low as 28.6 µg/mL against methicillin-resistant S. aureus. Alapropoginine caused negligible toxicity toward human red blood cells. Moreover, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their antimicrobial concentrations. (4) Conclusions: The present study indicates that alapropoginine exhibits promising antimicrobial activity against reference and resistant strains of bacteria with negligible hemolytic activity. Additionally, the peptide displays synergistic or additive effects when combined with several antibiotics.


Plants ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 74 ◽  
Author(s):  
Eugene Rogozhin ◽  
Dmitry Ryazantsev ◽  
Alexey Smirnov ◽  
Sergey Zavriev

Cereal-derived bioactive peptides with antimicrobial activity have been poorly explored compared to those from dicotyledonous plants. Furthermore, there are a few reports addressing the structural differences between antimicrobial peptides (AMPs) from cultivated and wild cereals, which may shed light on significant varieties in the range and level of their antimicrobial activity. We performed a primary structure analysis of some antimicrobial peptides from wild and cultivated cereals to find out the features that are associated with the much higher antimicrobial resistance characteristic of wild plants. In this review, we identified and analyzed the main parameters determining significant antifungal activity. They relate to a high variability level in the sequences of C-terminal fragments and a high content of hydrophobic amino acid residues in the biologically active defensins in wild cereals, in contrast to AMPs from cultivated forms that usually exhibit weak, if any, activity. We analyzed the similarity of various physicochemical parameters between thionins and defensins. The presence of a high divergence on a fixed part of any polypeptide that is close to defensins could be a determining factor. For all of the currently known hevein-like peptides of cereals, we can say that the determining factor in this regard is the structure of the chitin-binding domain, and in particular, amino acid residues that are not directly involved in intermolecular interaction with chitin. The analysis of amino acid sequences of alpha-hairpinins (hairpin-like peptides) demonstrated much higher antifungal activity and more specificity of the peptides from wild cereals compared with those from wheat and corn, which may be associated with the presence of a mini cluster of positively charged amino acid residues. In addition, at least one hydrophobic residue may be responsible for binding to the components of fungal cell membranes.


2009 ◽  
Vol 75 (9) ◽  
pp. 2735-2741 ◽  
Author(s):  
Joseph O. Falkinham ◽  
Thomas E. Wall ◽  
Justin R. Tanner ◽  
Khaled Tawaha ◽  
Feras Q. Alali ◽  
...  

ABSTRACT Anecdotes, both historical and recent, recount the curing of skin infections, including diaper rash, by using red soils from the Hashemite Kingdom of Jordan. Following inoculation of red soils isolated from geographically separate areas of Jordan, Micrococcus luteus and Staphylococcus aureus were rapidly killed. Over the 3-week incubation period, the number of specific types of antibiotic-producing bacteria increased, and high antimicrobial activity (MIC, ∼10 μg/ml) was observed in methanol extracts of the inoculated red soils. Antibiotic-producing microorganisms whose numbers increased during incubation included actinomycetes, Lysobacter spp., and Bacillus spp. The actinomycetes produced actinomycin C2 and actinomycin C3. No myxobacteria or lytic bacteriophages with activity against either M. luteus or S. aureus were detected in either soil before or after inoculation and incubation. Although protozoa and amoebae were detected in the soils, the numbers were low and did not increase over the incubation period. These results suggest that the antibiotic activity of Jordan's red soils is due to the proliferation of antibiotic-producing bacteria.


2022 ◽  
Vol 2 ◽  
Author(s):  
Oleh Andrukhov ◽  
Alice Blufstein ◽  
Christian Behm

Antimicrobial defense is an essential component of host-microbial homeostasis and contributes substantially to oral health maintenance. Dental mesenchymal stromal cells (MSCs) possess multilineage differentiation potential, immunomodulatory properties and play an important role in various processes like regeneration and disease progression. Recent studies show that dental MSCs might also be involved in antibacterial defense. This occurs by producing antimicrobial peptides or attracting professional phagocytic immune cells and modulating their activity. The production of antimicrobial peptides and immunomodulatory abilities of dental MSCs are enhanced by an inflammatory environment and influenced by vitamin D3. Antimicrobial peptides also have anti-inflammatory effects in dental MSCs and improve their differentiation potential. Augmentation of antibacterial efficiency of dental MSCs could broaden their clinical application in dentistry.


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