scholarly journals Evaluation of the Antimicrobial Activity of an Extract of Lactobacillus casei-Infected Hermetia illucens Larvae Produced Using an Automatic Injection System

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2121
Author(s):  
Kyu-Shik Lee ◽  
Eun-Young Yun ◽  
Tae-Won Goo
Keyword(s):  
Antimicrobial Activity ◽  
Quantitative Polymerase Chain Reaction ◽  
Antimicrobial Activities ◽  
Injection System ◽  
Lactobacillus Species ◽  
Resistant Bacteria ◽  
Gene Expressions ◽  
Minimal Inhibitory Concentrations ◽  
Mass Injection ◽  
Automatic Mass

In the present study, we developed an automatic mass-injection system (AMIS) to produce an extract of infected H. illucens larvae (iHIL-E) and then evaluated antimicrobial peptide (AMP) expressions and assessed the antimicrobial activity of iHIL-E against various pathogens and Lactobacillus species. AMP gene expressions were assessed by real-time quantitative polymerase chain reaction (PCR) and the antimicrobial activities of iHIL-E were estimated using a radial diffusion assay and by determining minimal inhibitory concentrations. Results showed that the antimicrobial activity of HIL extract was effectively enhanced by L. casei infection and that the gene expressions of cecropin 3 and defensin 3 (antimicrobial peptides) were up-regulated. iHIL-E also prevented the growths of Enterococcus faecalis, Streptococcus mutans, and Candida vaginitis (MICs 200, 500, and 1000 µg/100 µL, respectively) and demonstrated high protease resistance. Moreover, the growths of methicillin-resistant Staphylococcus aureus, antibiotic-resistant Pseudomonas aeruginosa and AMP-resistant bacteria, Serratia marcescens, and Pseudomons tolaasii were significantly suppressed by iHIL-E. In addition, although iHIL completely cleared Salmonella species at concentrations of >200 µg/100 µL, Lactobacillus species were unaffected by iHIL at concentrations of <1000 µg/100 µL. The present investigation shows that the devised automatic mass injection system is effective for the mass production of the extract of infected HIL and that this extract is a novel, natural, protease-resistant, antibiotic candidate with broad-spectrum antibiotic activity.

scholarly journals Antimicrobial Activity of an Extract of Hermetia illucens Larvae Immunized with Lactobacillus casei against Salmonella Species

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 704 ◽  
Author(s):  
Kyu-Shik Lee ◽  
Eun-Young Yun ◽  
Tae-Won Goo
Keyword(s):  
Antimicrobial Activity ◽  
Lactobacillus Casei ◽  
Salmonella Enteritidis ◽  
Inhibitory Concentration ◽  
Antimicrobial Activities ◽  
Lactobacillus Species ◽  
Gene Expressions ◽  
Hermetia Illucens ◽  
Salmonella Pullorum ◽  
Hermetia Illucens Larvae

The expressions of antimicrobial peptides (AMPs) in the larvae of the black soldier fly, Hermetia illucens, were significantly increased by pathogen or stimulant induced innate immunity activation. We immunized H. illucens fifth instar larvae with five different Lactobacillus species, that is, Lactobacillus acidophilus, L. brevis, L. casei, L. fermentum, or L. delbrueckii, to induce the mass production of AMPs and selected optimal immune inducers. Antimicrobial activities in hemolymph and H. illucens larvae (HIL) extract were evaluated against three salmonella species (Salmonella pullorum, Salmonella typhimurium, and Salmonella enteritidis). Highest antimicrobial activity was shown by the hemolymph of HIL immunized by L. casei and its activity was closely linked with the inductions of cecropin 1 (HiCec1) and defensin 1 (HiDef1) gene expressions. Furthermore, antimicrobial activity in hemolymph was stable to heat and pH and the growth of three Salmonella species were dramatically suppressed by HIL hemolymph and extract after immunization with L. casei. The minimal inhibitory concentration (MICs) of L. casei-immunized HIL extract against Staphylococcus aureus, Escherichia coli, and Salmonella species ranged from 100~200 µg/100 µL and no cytotoxicity to CaCo-2 and L929 cells were observed in the concentration range 100~40,000 µg/100 µL. Taken together, the present investigation demonstrates that L. casei-immunized HIL extract is a powerful natural antibiotic and preservative that can prevent contamination by Salmonella species.

scholarly journals The Design of Alapropoginine, a Novel Conjugated Ultrashort Antimicrobial Peptide with Potent Synergistic Antimicrobial Activity in Combination with Conventional Antibiotics

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Ali Salama ◽  
Ammar Almaaytah ◽  
Rula M. Darwish
Keyword(s):  
Antimicrobial Activity ◽  
Hemolytic Activity ◽  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Resistant Bacteria ◽  
Human Red Blood Cells ◽  
Drug Resistant Bacteria ◽  
Different Strains ◽  
Conventional Antibiotics

(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.

scholarly journals Antimicrobial activities of laboratory produced essential oil solutions against five selected fungal strains

2013 ◽  
pp. 171-183 ◽  
Author(s):  
Emilija Ivanova ◽  
Natalija Atanasova-Pancevska ◽  
Dzoko Kungulovski
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Antimicrobial Properties ◽  
Microtiter Plate ◽  
Antimicrobial Activities ◽  
Food Preservation ◽  
Minimal Inhibitory Concentrations ◽  
Fungal Strains ◽  
Treat Ment ◽  
Penicillium Spp

It is well known that essential oils possess significant antimicrobial activity. This study was conducted to estimate the antimicrobial activity of various types of Biokill, a laboratory produced solution composed of several essential oils (Biokill dissolved in 96% ethanol; Biokill 96% further dissolved in DMSO; Biokill dissolved in 70% ethanol and Biokill 70% further dissolved in DMSO). The antimicrobial activity was evaluated against five selected fungal strains, Candida albicans ATCC 10231, Saccharomyces cerevisiae ATCC 9763, Aspergillus niger I.N. 1110, Aspergillus sojae CCF and Penicillium spp. FNS FCC 266. A variation of the microtiter plate-based antimicrobial assay was used in order to assess the antimicrobial activity of the solutions. By applying this assay minimal inhibitory concentrations (MIC) of the Biokill solutions were determined for each strain of the selected test microorganisms. The results demonstrated that all variations of Biokill showed antimicrobial activity at concentrations lower than 2.5?g/mL. Biokill 70% further dissolved in DMSO showed the best antimicrobial properties against all the selected strains with MICs less than 1.25?g/mL. These results indicated that Biokill could find application in the pharmaceutical industry, in food preservation and conservation, in the prevention and treat?ment of plants infected by certain phytopathogens, etc.

Screening of Antimicrobial Activity and Cytotoxic Effects of Two Cladonia Species

2013 ◽  
Vol 68 (5-6) ◽  
pp. 191-197 ◽  
Author(s):  
Birkan Açıkgöz ◽  
İskender Karaltı ◽  
Melike Ersöz ◽  
Zeynep M. Coşkun ◽  
Gülşah Çobanoğlu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Activities ◽  
Chloroform Extract ◽  
Cytotoxic Effects ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Methanol Extracts ◽  
Gram Positive Bacteria

The present study explores the antimicrobial activity and cytotoxic effects in culture assays of two fruticose soil lichens, Cladonia rangiformis Hoffm. and Cladonia convoluta (Lamkey) Cout., to contribute to possible pharmacological uses of lichens. In vitro antimicrobial activities of methanol and chloroform extracts against two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus), and the yeast Candida albicans were examined using the paper disc method and through determination of minimal inhibitory concentrations (MICs). The data showed the presence of antibiotic substances in the chloroform and the methanol extracts of the lichen species. The chloroform extracts exhibited more signifi cant antimicrobial activity than the methanol extracts. However, a higher antifungal activity was noted in the methanol extract of C. rangiformis. The maximum antimicrobial activity was recorded for the chloroform extract of C. convoluta against E. coli. The cytotoxic effects of the lichen extracts on human breast cancer MCF-7 cells were evaluated by the trypan blue assay yielding IC50 values of ca. 173 and 167 μg/ml for the extracts from C. rangiformis and C. convoluta, respectively.

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 Antimicrobial and antibiofilm activity of the essential oil from dried leaves of Eucalyptus staigeriana

2019 ◽  
Vol 86 ◽  
Author(s):  
Marcos Saldanha Correa ◽  
Joseli Schwambach ◽  
Michele Bertoni Mann ◽  
Jeverson Frazzon ◽  
Ana Paula Guedes Frazzon
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistant Bacteria ◽  
Antibiofilm Activity ◽  
Gram Positive ◽  
Promising Alternative ◽  
Gram Negative

ABSTRACT: In recent years, compounds with biological properties produced by plants have received attention as an alternative to control microorganisms. Essential oils extracted from green leaves of Eucalyptus sp. have been demonstrated to have antimicrobial activities, but so far there are no reports of antimicrobial activity of essential oils extracted from dried leaves of Eucalyptus staigeriana. So, the objectives of this study were to determine the chemical composition of the essential oils obtained from dried leaves of E. staigeriana (EOdlES) and to evaluate in vitro antimicrobial and antibiofilm activities of EOdlES against gram-positive and gram-negative, resistance and multiresistant Enterococcus faecalis isolated from food and clinical samples. The characterization of EOdlES was performed by gas chromatography-mass spectrometry (GC/MS). For this study, 26 bacterial strains were used, which included 11 reference strains and 15 antibiotic resistant and multiresistant E. faecalis strains. Antimicrobial activities of EOdlES against gram-positive and gram-negative were determined using the disc diffusion method. The minimum inhibitory concentration (MIC) value was evaluated by a microbroth dilution technique. The antibiofilm effects were assessed by microtiter plate method. As a result, 21 compounds were identified, being oxygenated monoterpenes (69.58%) the major chemical family. EOdlES showed only antimicrobial activity against gram-positive strains. E. faecalis resistant and multiresistant strains show the lowest MIC (3.12 to 6.25%), when compared with reference E. faecalis strain. EOdlES has the ability to inhibit the biofilm formation, but little or none ability to inhibit the preformed biofilm. This study demonstrates that EOdlES is a promising alternative to control important foodborne and clinic gram-positive resistant bacteria.

scholarly journals Potential of Novel Antimicrobial Peptide P3 from Bovine Erythrocytes and Its Analogs To Disrupt Bacterial MembranesIn Vitroand Display Activity against Drug-Resistant Bacteria in a Mouse Model

2015 ◽  
Vol 59 (5) ◽  
pp. 2835-2841 ◽  
Author(s):  
Qinghua Zhang ◽  
Yanzhao Xu ◽  
Qing Wang ◽  
Bolin Hang ◽  
Yawei Sun ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Body Weight ◽  
Mouse Model ◽  
Antimicrobial Activities ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria ◽  
Resistant Strains ◽  
Bovine Erythrocytes

ABSTRACTWith the emergence of many antibiotic-resistant strains worldwide, antimicrobial peptides (AMPs) are being evaluated as promising alternatives to conventional antibiotics. P3, a novel hemoglobin peptide derived from bovine erythrocytes, exhibited modest antimicrobial activityin vitro. We evaluated the antimicrobial activities of P3 and an analog, JH-3, bothin vitroandin vivo. The MICs of P3 and JH-3 ranged from 3.125 μg/ml to 50 μg/ml when a wide spectrum of bacteria was tested, including multidrug-resistant strains. P3 killed bacteria within 30 min by disrupting the bacterial cytoplasmic membrane and disturbing the intracellular calcium balance. Circular dichroism (CD) spectrometry showed that P3 assumed an α-helical conformation in bacterial lipid membranes, which was indispensable for antimicrobial activity. Importantly, the 50% lethal dose (LD50) of JH-3 was 180 mg/kg of mouse body weight after intraperitoneal (i.p.) injection, and no death was observed at any dose up to 240 mg/kg body weight following subcutaneous (s.c.) injection. Furthermore, JH-3 significantly decreased the bacterial count and rescued infected mice in a model of mouse bacteremia. In conclusion, P3 and an analog exhibited potent antimicrobial activities and relatively low toxicities in a mouse model, indicating that they may be useful for treating infections caused by drug-resistant bacteria.

scholarly journals Synthesis and Antimicrobial Activities of 5-Arylidene-thiazolidine-2,4-dione Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ivanildo Mangueira da Silva ◽  
João da Silva Filho ◽  
Priscila Brandão Gomes da Silva Santiago ◽  
Micalyne Soares do Egito ◽  
Carlos André de Souza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Bacterial Resistance ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Disc Diffusion Method ◽  
Pharmacological Activities ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Repeated Use

Antibiotic resistance is considered one of the world's major public health concerns. The main cause of bacterial resistance is the improper and repeated use of antibiotics. To alleviate this problem, new chemical substances against microorganisms are being synthesized and tested. Thiazolidines are compounds having many pharmacological activities including antimicrobial activities. For this purpose some thiazolidine derivatives substituted at position 5 in the thiazolidine nucleus were synthesized and tested against several microorganisms. Using a disc diffusion method, antimicrobial activity was verified against Gram-positive, Gram-negative, and alcohol acid resistant bacteria and yeast. The minimum inhibition concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined. All derivatives showed antimicrobial activity mainly against Gram-positive bacteria, with MIC values ranging from 2 to 16 µg/mL.

scholarly journals ANTIMICROBIAL ACTIVITIES OF SUCCESSIVE SOLVENT EXTRACTS OF ALBIZIA LEBBECK AND SOLANUM SEAFORTHIANUM AGAINST SOME HUMAN PATHOGENIC MICROORGANISMS

2019 ◽  
pp. 294-296
Author(s):  
HOSUR NARAYANAPPA VENKATESH ◽  
DEVIHALLI CHIKKAIAH MOHANA
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Negative Impact ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Albizia Lebbeck ◽  
Minimal Inhibitory Concentrations ◽  
Broth Dilution

Objective: The continuous emergence of multidrug resistance bacteria and yeast, and the negative impact of synthetic preservatives have led to an increased interest in the use of plant extracts as alternative antimicrobial agents. In the present investigation, the antimicrobial activity of successive solvent extracts of Albizia lebbeck and Solanum seaforthianum has been evaluated against human pathogenic bacteria and yeast. Methods: The disc diffusion method was employed for determination of the zone of inhibitions (ZOIs) and twofold broth dilution technique was employed for determination of minimal inhibitory concentrations, and minimal bactericidal/fungicidal concentrations. Results: Among the successive solvent extracts tested, methanol extracts of both A. lebbeck and S. seaforthianum showed highest antibacterial activity with ZOIs ranged between 10.0 and 20.4 mm at 1 mg/disc followed by ethanol (ZOIs 8.1–17.6 mm). The petroleum ether, toluene, and chloroform extracts showed the least activity. The highest activity was observed against Streptococcus faecalis, whereas the least activity was observed against Pseudomonas aeruginosa. Conclusion: The broad-spectrum antimicrobial activity of methanol extract of A. lebbeck and S. seaforthianum could be explored as antimicrobial agents for the management of pathogenic bacteria and yeast.

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.

Sign in / Sign up

Export Citation Format

Share Document