scholarly journals Expression and Functional Characterization of a Novel Antimicrobial Peptide: Human Beta-Defensin 118

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Qian Lin ◽  
Kunhong Xie ◽  
Daiwen Chen ◽  
Bing Yu ◽  
Xiangbing Mao ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Functional Characterization ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Tnf Α ◽  
Novel Host ◽  
Host Defense Peptide ◽  
Late Apoptosis

Purpose. β-Defensin 118 (DEFB118) is a novel host defense peptide (HDP) identified in humans. To evaluate its potentials for future utilization, the DEFB118 gene was expressed in Escherichia coli (E. coli) and the recombinant protein was fully characterized. Methods. The DEFB118 protein was obtained by heterologous expression using E. coli Rosetta (DE3). Antibacterial activity of DEFB118 was determined by using various bacterial strains. IPEC-J cells challenged by E. coli K88 were used to determine its influences on inflammatory responses. Results. The E. coli transformants yielded more than 250 μg/mL DEFB118 protein after 4 h induction by 1.0 mM IPTG. The DEFB118 was estimated by SDS-PAGE to be 30 kDa, and MALDI-TOF analysis verified that it is a human β-defensin 118. Importantly, the DEFB118 showed antimicrobial activities against both Gram-negative bacteria (E. coli K88 and E. coli DH5α) and Gram-positive bacteria (S. aureus and B. subtilis), with a minimum inhibitory concentration (MIC) of 4 μg/mL. Hemolytic assays showed that DEFB118 had no detrimental impact on cell viability. Additionally, DEFB118 was found to elevate the viability of IPEC-J2 cells upon E. coli K88 challenge. Moreover, DEFB118 significantly decreased cell apoptosis in the late apoptosis phase and downregulated the expression of inflammatory cytokines such as IL-1β and TNF-α in IPEC-J2 cell exposure to E. coli K88. Conclusions. These results suggested a novel function of the mammalian defensins, and the antibacterial and anti-inflammatory properties of DEFB118 may allow it as a potential substitute for conventionally used antibiotics or drugs.

scholarly journals Expression and functional characterization of a novel antimicrobial peptide: human beta-defensin118

2020 ◽  
Author(s):  
Qian Lin ◽  
KunHong Xie ◽  
Daiwen Chen ◽  
Bing Yu ◽  
Xiangbing Mao ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Functional Characterization ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Sds Page ◽  
Novel Host ◽  
Late Apoptosis

Abstract Background: β-defensin 118 (DEFB118 ) is a novel host defence peptide (HDP) identified in human. To evaluate its potentials for future utilization, the DEFB118 gene was expressed in Escherichia coli ( E. coli ) and the recombinant protein was fully characterized. Methods: The DEFB118 protein was obtained by heterologous expression using E. coli Rosetta (DE3). Antibacterical activity of DEFB118 were determined by using various bacterial strains. IPEC-J cells challenged by E. coli K88 were used to determine its influences on inflammatory responses. Results: The E. coli transformants yielded more than 250 mg/mL D EFB118 protein after 4 h induction by 1.0 mM IPTG. The DEFB118 was estimated by SDS-PAGE to be 30 kDa, and MALDI-TOF analysis verified it is a human β-defensin 118. Importantly, the DEFB118 showed antimicrobial activities against both Gram-negative bacteria ( E. coli K88 and E. coli DH5α) and Gram-positive bacteria ( S. aureus and B. subtilis ), with a minimum inhibitory concentration (MIC) of 4 μg/mL. Hemolytic assays showed that DEFB118 had no detrimental impact on cell viability. Additionally, DEFB118 was found to elevate the viability of IPEC-J2 cells upon E. coli K88 challenge. Moreover, DEFB118 significantly decreased cell apoptosis in the late apoptosis phase and down-regulated the expression of inflammatory cytokines such as the IL-1β and TNF-a in the IPEC-J2 cells exposure to E. coli K88. Conclusions: These results suggested a novel function of the mammalian defensins, and the anti-bacterial and anti-inflammatory properties of DEFB118 may allow it a potential substitute for conventionally used antibiotics or drugs.

scholarly journals Functional Characterization of Porcine NK-Lysin: A Novel Immunomodulator That Regulates Intestinal Inflammatory Response

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4242
Author(s):  
Qian Lin ◽  
Qingqing Fu ◽  
Daiwen Chen ◽  
Bing Yu ◽  
Yuheng Luo ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Functional Characterization ◽  
Antibacterial Activities ◽  
Bacterial Strains ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Tnf Α ◽  
Sds Page ◽  
Junction Protein

Porcine NK-Lysine (PNKL) is a new antimicrobial peptide (AMP) identified in the small intestine. In this study, PNKL protein was obtained through heterologous expression in Escherichia coli and was estimated by SDS-PAGE at 33 kDa. The antibacterial activities of PNKL were determined using various bacterial strains and showed broad-spectrum antimicrobial activity against Gram-negative and Gram-positive bacteria. Furthermore, E. coli K88-challenged IPEC-J2 cells were used to determine PNKL influences on inflammatory responses. Hemolytic assays showed that PNKL had no detrimental impact on cell viability. Interestingly, PNKL elevated the viability of IPEC-J2 cells exposure to E. coli K88. PNKL significantly decreased the cell apoptosis rate, and improved the distribution and abundance of tight junction protein ZO-1 in IPEC-J2 cells upon E. coli K88-challenge. Importantly, PNKL not only down regulated the expressions of inflammatory cytokines such as the IL-6 and TNF-α, but also down regulated the expressions of NF-κB, Caspase3, and Caspase9 in the E. coli K88-challenged cells. These results suggest a novel function of natural killer (NK)-lysin, and the anti-bacterial and anti-inflammatory properties of PNKL may allow it a potential substitute for conventionally used antibiotics or drugs.

scholarly journals DPPH-Scavenging and Antimicrobial Activities of Asteraceae Medicinal Plants on Uropathogenic Bacteria

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Phan-Canh Trinh ◽  
Le-Thi-Thanh Thao ◽  
Hoang-Tran-Viet Ha ◽  
TuAnh Nguyen
Keyword(s):  
Antimicrobial Agents ◽  
Natural Antioxidants ◽  
Ethyl Acetate Fraction ◽  
Antimicrobial Activities ◽  
Chrysanthemum Morifolium ◽  
Bacterial Strains ◽  
Ageratum Conyzoides ◽  
Potent Effect ◽  
E Coli ◽  
Dpph Scavenging

Asteraceae species were widely applied in traditional medicines in Asian countries as sources of natural antioxidants and antimicrobial agents. This study aimed to evaluate DPPH-scavenging capacities and antimicrobial activities of nine Asteraceae species collected from Southern Vietnam. Antioxidant and antimicrobial activities were determined by standard protocols. Essential oils from Ageratum conyzoides, Helianthus annuus, and Artemisia vulgaris indicated significant inhibitory effects on Staphylococcus aureus and Candida spp. Crude extracts and fractions from Taraxacum officinale, Chrysanthemum morifolium, A. conyzoides, and Tagetes erecta showed inhibitory ability on at least one testing bacterial strains including S. aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In a study on clinical isolates, ethyl acetate fraction from A. conyzoides flower displayed the most potent effect on uropathogenic E. coli and K. pneumoniae with MIC at 1.25–10 mg/ml and 5–12.5 mg/ml, respectively. DPPH-scavenging assay indicated that T. erecta extract had the lowest IC50 (17.280 μg/ml) and is 2.4 times higher than vitamin C (7.321 μg/ml). This study revealed that A. conyzoides has good potential against uropathogenic E. coli and K. pneumoniae, and therefore could be applied for prophylactic treatment of urinary infection.

scholarly journals Viability of lactic acid bacteria in different components of Ogi with anti diarrhoeagenic E. coli activities

2019 ◽  
Vol 3 (6) ◽  
pp. 206-213
Author(s):  
Roseline Eleojo Kwasi ◽  
Iyanuoluwa Gladys Aremu ◽  
Qudus Olamide Dosunmu ◽  
Funmilola A. Ayeni
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Antimicrobial Properties ◽  
Culture Method ◽  
Antimicrobial Activities ◽  
Drying Methods ◽  
Bacterial Strains ◽  
E Coli ◽  
Log Reduction ◽  
Freeze Dried

Background: Ogi constitutes a rich source of lactic acid bacteria (LAB) with associated health benefits to humans through antimicrobial activities. However, the high viability of LAB in Ogi and its supernatant (Omidun) is essential. Aims: This study was carried out to assess the viability of LAB in various forms of modified and natural Ogi and the antimicrobial properties of Omidun against diarrhoeagenic E coli. Methods and Material: The viability of LAB was assessed in fermented Ogi slurry and Omidun for one month and also freeze-dried Ogi with and without added bacterial strains for two months. A further 10 days viability study of modified Omidun, refrigerated Omidun, and normal Ogi was performed. The antimicrobial effects of modified Omidun against five selected strains of diarrhoeagenic E. coli (DEC) were evaluated by the co-culture method. Results: Both drying methods significantly affected carotenoids and phenolic compounds. The Ogi slurry had viable LAB only for 10 days after which, there was a succession of fungi and yeast. Omidun showed 2 log10cfu/ml reduction of LAB count each week and the freeze-dried Ogi showed progressive reduction in viability. Refrigerated Omidun has little viable LAB, while higher viability was seen in modified Omidun (≥2 log cfu/ml) than normal Omidun. Modified Omidun intervention led to 2-4 log reduction in diarrhoeagenic E. coli strains and total inactivation of shigella-toxin producing E. coli H66D strain in co-culture. Conclusions: The consumption of Ogi should be within 10 days of milling using modified Omidun. There are practical potentials of consumption of Omidun in destroying E. coli strains implicated in diarrhea. Keywords: Ogi, Omidun, lactic acid bacteria, diarrhoeagenic Escherichia coli strains, Viability.

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 Innate Immune Responses of Human Neonatal Cells to Bacteria from the Normal Gastrointestinal Flora

2002 ◽  
Vol 70 (12) ◽  
pp. 6688-6696 ◽  
Author(s):  
Helen Karlsson ◽  
Christina Hessle ◽  
Anna Rudin
Keyword(s):  
Immune System ◽  
Mononuclear Cells ◽  
Innate Immune ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Tnf Α ◽  
Adult Cells

ABSTRACT The hygiene hypothesis postulates that the prevalence of allergy has increased due to decreased microbial stimulation early in life, leading to delayed maturation of the immune system. The aim of this study was to examine the cytokine pattern produced from cord blood mononuclear cells relative to adult cells after stimulation with bacterial strains from the normal flora. Mononuclear cells from cord and adult blood samples were stimulated with the following bacteria: Bifidobacterium adolescentis, Enterococcus faecalis, Lactobacillus plantarum, Streptococcus mitis, Corynebacterium minutissimum, Clostridium perfringens, Bacteroides vulgatus, Escherichia coli, Pseudomonas aeruginosa, Veillonella parvula, and Neisseria sicca. The levels of interleukin 12 (IL-12), tumor necrosis factor alpha (TNF-α), IL-10, and IL-6 were measured by enzyme-linked immunosorbent assay. The TNF-α production was also analyzed after blocking CD14, Toll-like receptor 2 (TLR-2), and TLR-4 prior to stimulation with bacteria. The levels of IL-12 and TNF-α were similar in cord and adult cells. Gram-positive bacteria induced considerably higher levels of IL-12 and TNF-α than gram-negative bacteria in both cord and adult cells. The levels of IL-6 were significantly higher in newborns than in adults, whereas the levels of IL-10 were similar in newborns and adults. Gram-negative and gram-positive bacteria induced similar levels of IL-6 and IL-10 in cord cells. L. plantarum bound or signaled through CD14, TLR-2, and TLR-4, whereas E. coli acted mainly through CD14 and TLR-4. These results indicate that the innate immune response in newborns to commensal bacteria is strong and also suggest that different bacterial strains may have differential effects on the maturation of the immune system of infants.

scholarly journals Antibacterial Activity of the Essential Oil of Heracleum Sibiricum

2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Dragoljub L. Miladinović ◽  
Budimir S. Ilić ◽  
Tatjana M. Mihajilov-Krstev ◽  
Dejan M. Nikolić ◽  
Olga G. Cvetković ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Essential Oil ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Gram Positive Bacteria ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Major Chemical ◽  
Total Oil ◽  
Chemical Class

The composition and antimicrobial activity of the essential oil of Heracleum sibiricum L. (Apiaceae) was studied. The aerial part of plant was hydro-distilled and chemical composition of the essential oil was analyzed by GC and GC-MS. Forty-six compounds, corresponding to 95.12% of the total oil, were identified. Esters represented the major chemical class (69.55%) while the main constituents were octyl butanoate (36.82%), hexyl butanoate (16.08%), 1-octanol (13.62%) and octyl hexanoate (8.10%). Antibacterial activity of the essential oil and reference antibiotics against nine bacterial strains was tested by the broth microdilution method. The results of the bioassays showed that essential oil had slight antimicrobial activities against all tested microorganisms (MIC and MBC values were in the range of 2431.2 to 9724.8 μg/mL). Reference antibiotics were active in concentrations between 0.5 and 16.0 μg/mL. The results confirm that Gram-positive bacteria were more susceptible to the essential oil of H. sibiricum, in comparison with Gram-negative bacteria.

scholarly journals Synthesis of sulfonamides bearing 1,3,5-triarylpyrazoline and 4-thiazolidinone moieties as novel antimicrobial agents

2020 ◽  
Vol 85 (2) ◽  
pp. 155-162
Author(s):  
Thi-Dan Thach ◽  
Thi Le ◽  
Thien-Annguyen Nguyen ◽  
Chi-Hien Dang ◽  
Van-Su Dang ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Significant Inhibition ◽  
Mercaptoacetic Acid ◽  
Bacterial Strains ◽  
Reference Drug ◽  
E Coli ◽  
Yeast Strains ◽  
Microbial Strains

Two series of sulfonamides were synthesized from 4-hydrazinylbenzenesulfonamide as the key starting material. 1,3,5-Triarylpyrazoline sulfonamides (2a?i) were obtained by cyclocondensation of various chalcones in 53? ?64 % yields, while 4-thiazolidinone derivatives (4a?e) were synthesized by cyclocondensation between mercaptoacetic acid and different phenylhydrazones in 43?62 % yields. The synthesized compounds were characterized based on FTIR, 1H-NMR, 13C-NMR and HRMS data. The sulfonamides were evaluated for their in vitro antimicrobial activities against four bacterial strains (E. coli, P. aeruginosa, B. subtillis and S aureus), two filamentous fungal strains (A. niger and F. oxysporum) and two yeast strains (C. albicans and S. cerevisiae). Seven pyrazolines, 2a?c and 2e?h, exhibited significant inhibition of different microbial strains. Among them, compound 2b displayed good antifungal activity against A. niger (MIC value at 12.5 ?g mL-1) over the reference drug.

scholarly journals Escherichia coli and Staphylococcus aureus responsible for bovine mastitis sensitivity to the essential oil of Algerian Thymus fontanesii Boiss. et Reut.

2020 ◽  
Vol 7 (1) ◽  
pp. 26-32
Author(s):  
Bendella Amina nor elhouda ◽  
Ghazi Kheira ◽  
Meliani Samia
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Bovine Mastitis ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Zones Of Inhibition

AbstractThe aim of this study is to test two different methods for evaluating the in vitro antibacterial effect of Thymus fontanesii Boiss. et Reut. essential oil against standard and clinical bacterial strains responsible for bovine mastitis: the disc diffusion method or the aromatogram which allows the demonstration of the antibacterial power of essential oils on the bacterial strains tested, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and two strains isolated from bovine mastitis milk S. aureus and E. coli. The inhibition activity of the essential oil of T. fontanesii on bacterial strains by the two methods shows that the antimicrobial power of this oil is very important and is characterized by bactericidal and bacteriostatic action against gram negative and gram positive bacteria. The antimicrobial evaluation by the aromatogram showed good antibacterial activity against all the strains tested, the zones of inhibition of the bacteria were between 23,33±1,527mm and 37,5±3,535 mm. The search for minimum inhibitory concentrations MIC and bactericides CMB made it possible to quantitatively assess the antimicrobial power of this essential oil. In this work, the MIC was 0,625 µl/ml for all strains tested, and the lowest CMB was that of T. fontanesii against E. coli ATCC 25922 was 0,625 µl/ml.

scholarly journals Synthesis, Characterization and Antimicrobial Activities of Co (III) and Fe (III) Complexes of Imino-N-heterocyclic Carbenes Ligands

2021 ◽  
pp. 59-67
Author(s):  
Samaila Abubakar ◽  
Musa Muktari ◽  
Rejoice Atiko
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhi ◽  
Antimicrobial Activities ◽  
Heterocyclic Carbenes ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

The synthesis and antimicrobial application of Co (III) and Fe (III) complexes of imine functionalized N-heterocyclic carbene (Imino-NHC) ligands is reported. The ligand precursors 1-(2-[(hydroxyl-benzylidene)-amino]-ethyl)-3-R-3H-imidazol-1-ium bromide where R = pyridyl (1a) and benzyl (1b) have been reported in our previous work. The in-situ generated ligands of 1a and 1b have been successfully coordinated to CoBr2 and [FeI(Cp)(CO)2] leading to the isolation of air-stable N^C^N^O four coordinate Co(III)  complex 2 and a six-coordinate Fe(III) complex 3. The synthesised complexes were both found to be NMR inactive hence were characterize using FTIR and LRMS. The complexes were screened for antimicrobial activities against four gram-negative bacteria Escherichia Coli (E-coli), Shigella, Klebsiella pneumoniae (K. Pneumoniae) and Salmonella typhi (S. typhi) and a gram positive bacteria Staphylocossus aureus (S. aureus). The antimicrobial test was conducted using disc diffusion methods and based on the concentrations of 100, 200, 300, 400 and 500 µg/ mL, significant activities were recorded for both cobalt and the iron complexes.

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