Bacillus phage endolysin, lys46, bactericidal properties against Gram-negative bacteria

Background and Objectives: The great potential of bacteriophage for removing pathogen bacteria via targeting the cell wall is highly concerned. With a priority for overcoming drug-resistance, we screened against endolysins targeting Gram-negative bacteria to introduce a new antibacterial agent. This study was aimed to identify endolysins from the lysogenic phage of the Siphoviridea family in Bacillus subtilis. Materials and Methods: The Bacillus subtilis strain DDBCC46 was isolated from a preliminary antibacterial screening program. The endolysin (s) was extracted, concentrated with ammonium sulfate saturation, and their activity evaluated against the indicator bacteria. The phage particles were extracted from the bacteria using the minimum inhibition concentration of mitomycin C, followed by testing the phage inhibitory effect on the growth of indicator bacteria. The NCBI, Virus-Host DB, and EXPASY databases were used to obtain and confirm the sequences of the genes encoding PG hydrolases in Siphoviridea phages hosted in B. subtilis. Results: An 816 bp gene encoding an endolysin enzyme, was approved in the B. subtilis DDBCC 46, with specific primers of Bacillus phage SPP1. The purified-endolysin indicated antibacterial activity against Klebsiella pneumoniae, Salmonella typhimurium, Proteus (sp), and Escherichia coli. SDS-PAGE profiling followed by silica gel purification, led to introduceLys4630 as a therapeutic product and food preservative. Conclusion: lys4630 showed antibacterial effects on the common Gram-negative pathogens in clinics and food industries; E. coli, P. aeruginosa and Salmonella (sp).

Download Full-text

The fnr Gene of Bacillus licheniformis and the Cysteine Ligands of the C-Terminal FeS Cluster

Journal of Bacteriology ◽

10.1128/jb.180.13.3483-3485.1998 ◽

1998 ◽

Vol 180 (13) ◽

pp. 3483-3485 ◽

Cited By ~ 12

Author(s):

Anette Klinger ◽

Jan Schirawski ◽

Philippe Glaser ◽

Gottfried Unden

Keyword(s):

Bacillus Subtilis ◽

Nitrate Reductase ◽

Bacillus Licheniformis ◽

Anaerobic Bacterium ◽

Transcriptional Regulators ◽

Anaerobic Growth ◽

Gram Negative Bacteria ◽

Gene Encoding ◽

Gram Negative ◽

Terminal Cluster

ABSTRACT In the facultatively anaerobic bacterium Bacillus licheniformis a gene encoding a protein of the fumarate nitrate reductase family of transcriptional regulators (Fnr) was isolated. Unlike Fnr proteins from gram-negative bacteria, but like Fnr fromBacillus subtilis, the protein contained a C-terminal cluster of cysteine residues. Unlike in Fnr from B. subtilis, this cluster (Cys226-X2-Cys229-X4-Cys234) is composed of only three Cys residues, which are supposed to serve together with an internal residue (Cys71) as the ligands for an FeS center. Transfer of the B. licheniformis gene to anfnr mutant of B. subtilis complemented the ability for synthesis of nitrate reductase during anaerobic growth.

Download Full-text

Identification and characterisation of antimicrobial activity of nisin a produced by Lactococcus lactis subsp. lactis LL27

Czech Journal of Food Sciences ◽

10.17221/151/2008-cjfs ◽

2009 ◽

Vol 27 (No. 1) ◽

pp. 55-64 ◽

Cited By ~ 7

Author(s):

P. Şanlibaba ◽

N. Akkoç ◽

M. Akçelik

Keyword(s):

Lactococcus Lactis ◽

Ribosomal Rna ◽

Heat Stability ◽

Raw Milk ◽

Inhibitory Effect ◽

Proteinase K ◽

Gram Negative Bacteria ◽

Direct Pcr ◽

Gene Encoding ◽

Gram Negative

In this study, bacteriocin producing lactococcal strains were isolated from Turkish raw milk samples. Among these isolates, LL27 had the highest inhibition activity against Gram-positive indicator strains, and was selected for further analyses. DNA sequencing of 16S ribosomal RNA gene demonstrated that the isolate was Lactococcus lactis subsp. lactis. The gene encoding the bacteriocin in this strain was found to be identical to that of nisin A using direct PCR sequence methods. The bacteriocin was completely inactivated by α-chymotrypsin and proteinase K and partially inactivated by lipase and α-amylase. pH and heat stability characteristics were found to be identical with those of the control nisin. The inhibitory activity of the bacteriocin produced by LL27 was also evaluated against Gram-negative bacteria in combination with heat and freezing treatments. The results obviously showed that the production level of nisin of the Lc. lactis LL27 had a significant inhibitory effect on the pathogenic Gram-negative strains with the heating and freezing processes which are commonly used in the food processing.

Download Full-text

Specific Inhibition of Endotoxin Coating of Red Cells by a Human Erythrocyte Membrane Component

Infection and Immunity ◽

10.1128/iai.1.1.98-108.1970 ◽

1970 ◽

Vol 1 (1) ◽

pp. 98-108

Author(s):

Georg F. Springer ◽

Shankar V. Huprikar ◽

Erwin Neter

Keyword(s):

Human Erythrocyte ◽

Inhibitory Effect ◽

Red Cells ◽

Ion Concentration ◽

Gram Negative Bacteria ◽

Hydrogen Ion Concentration ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Common Antigens ◽

Vi Antigen

We have isolated from human erythrocyte ghosts a fraction which prevents the attachment of unheated as well as heated lipopolysaccharides of gram-negative bacteria to red cells. This material has no significant inhibitory effect either toward the Vi antigen of gram-negative bacteria or towards the group and common antigens of the gram-positive bacteria investigated. We, therefore, named this fraction “lipopolysaccharide receptor.” The receptor interacts with lipopolysaccharides and not with erythrocytes, it forms complexes with and blocks those groupings of lipopolysaccharides which attach to red cells. The effect of the receptor is physical and not enzymatic. The interaction of the receptor with the lipopolysaccharides is reversible, and the receptor removes lipopolysaccharides fixed to red cells. An equilibrium of lipopolysaccharide distribution between cells and receptor is established when receptor-lipopolysaccharide complexes are incubated with red cells. The receptor is labile toward heat and deviation of the hydrogen ion concentration from neutrality; aldehydes destroy its inhibitory activity.

Download Full-text

Chemical Composition and in Vitro Antibacterial Activity of the Essential Oil of Minthostachys Mollis (Kunth) Griseb Vaught from the Venezuelan Andes

Natural Product Communications ◽

10.1177/1934578x0900400726 ◽

2009 ◽

Vol 4 (7) ◽

pp. 1934578X0900400 ◽

Cited By ~ 2

Author(s):

Flor D. Mora ◽

María Araque ◽

Luis B. Rojas ◽

Rosslyn Ramírez ◽

Bladimiro Silva ◽

...

Keyword(s):

Antibacterial Activity ◽

Essential Oil ◽

Chemical Constituents ◽

Salmonella Typhi ◽

Inhibitory Effect ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Significant Inhibitory Effect ◽

In Vitro Antibacterial Activity

Chemical constituents of the essential oil from the leaves of Minthostachys mollis (Kunth) Griseb Vaught var. mollis collected in January 2008 at Tuñame, Trujillo State, Venezuela, were separated and identified by GCMS analysis. The essential oil was obtained by hydrodistillation and thirteen components (98.5% of the sample) were identified by comparison with the Wiley GCMS library data base. The two major components were pulegone (55.2%) and trans-menthone (31.5%). The essential oil showed a significant inhibitory effect against Gram-positive and Gram-negative bacteria, especially Bacillus subtilis and Salmonella typhi (4 μg/mL).

Download Full-text

Antibacterial Screening of some Heterocyclic Compounds Containing Quinoline Nucleus

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.76.27 ◽

2017 ◽

Vol 76 ◽

pp. 27-40

Author(s):

Shipra Baluja ◽

Nilesh Godvani ◽

Sumitra Chanda

Keyword(s):

Heterocyclic Compounds ◽

Antibacterial Activities ◽

Diffusion Method ◽

Spectroscopic Methods ◽

Gram Negative Bacteria ◽

Gram Negative ◽

H Nmr ◽

Antibacterial Screening ◽

Derivatives Of ◽

Agar Well Diffusion Method

In this work, some novel derivatives of Cyanopyridines and Isoxazoles were synthesized using Vilsmeier-Haack reagent and their structures were confirmed by FTIR, 1H NMR and mass spectroscopic methods. The antibacterial activities of these synthesized compounds were studied in DMSO and DMF by agar well diffusion method against some Gram positive and Gram negative bacteria. It is observed that activity depends upon three S: solvent, strain and structure.

Download Full-text

Antibacterial activity in the leaves of seven bitter medicinal plants of Bangladesh

Journal of Bio-Science ◽

10.3329/jbs.v18i0.8788 ◽

1970 ◽

Vol 18 ◽

pp. 128-133 ◽

Cited By ~ 1

Author(s):

MTH Molla ◽

MS Ahsan ◽

MT Alam ◽

ME Haque

Keyword(s):

Antibacterial Activity ◽

Bacillus Subtilis ◽

Medicinal Plants ◽

Plant Extracts ◽

Salmonella Typhi ◽

Antimicrobial Activities ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Ethanolic Extracts

Context: Development of resistance in human pathogens against conventional antibiotic necessitates searching indigenous medicinal plants having antibacterial property. Seven medicinal plants used actively in folklore, ayurvedic and traditional system of medicine were selected for the evaluation of their antimicrobial activity for this study. Objectives: Evaluation of the effectiveness of some medicinal plant extracts against four Gram-positive and five Gram-negative bacteria. Materials and Methods: The antibacterial activity of the crude ethanolic extracts obtained from the leaves of seven medicinal plants; viz., Andrographis paniculata, Catharanthus roseus, Adhatoda vasica, Vitex vegundo, Aloe vera, Flacortia ramontchi and Nyctanthes arbortristis were tested against nine bacteria at concentrations of 300-, 400- and 500 μg/ml. Standard antibiotic disc kanamycin (30μg/ml) was used for comparison. The minimum inhibitory concentration (MIC) of ethanolic extracts of the leaves of these medicinal plants were determined by testing the extracts on four Gram-positive and five Gram-negative bacteria by serial tube dilution method. Results: All the extracts have notable antimicrobial activities against the test organisms. The ethanolic extracts of the leaves showed the highest antimicrobial activities against Bacillus megaterium and Shigella dysenteriae for An. paniculata, Ad. vasica and Al. vera; Bacillus subtilis and Salmonella typhi for C. roseus and N. arbortristis; Staphylociccus aureus and Salmonella typhi for V. vegundo; and Bacillus subtilis and Shigella sonnei for F. ramontchi respectively. The extract of the plants had MIC values ranging from 32 to 128 mg/ml. All plant extracts showed no MIC against Shigella shiga and against Sarcina lutea only C. roseus showed MIC 128 mg/ml. Conclusion: The results revealed that the ethanolic extracts of the plants under present investigation have notable antimicrobial activities. Keywords: medicinal plants; antimicrobial screening; MIC; bacteria. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8788 JBS 2010; 18(0): 128-133

Download Full-text

A novel mechanism-based pharmacokinetic–pharmacodynamic (PKPD) model describing ceftazidime/avibactam efficacy against β-lactamase-producing Gram-negative bacteria

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz440 ◽

2019 ◽

Cited By ~ 1

Author(s):

Anders N Kristoffersson ◽

Caterina Bissantz ◽

Rusudan Okujava ◽

Andreas Haldimann ◽

Isabelle Walter ◽

...

Keyword(s):

Inhibitory Effect ◽

Dose Finding ◽

Gram Negative Bacteria ◽

Data Set ◽

Gram Negative ◽

Pkpd Model ◽

Index Approach ◽

Antibiotic Effect ◽

Time Kill

Abstract Background Diazabicyclooctanes (DBOs) are an increasingly important group of non β-lactam β-lactamase inhibitors, employed clinically in combinations such as ceftazidime/avibactam. The dose finding of such combinations is complicated using the traditional pharmacokinetic/pharmacodynamic (PK/PD) index approach, especially if the β-lactamase inhibitor has an antibiotic effect of its own. Objectives To develop a novel mechanism-based pharmacokinetic–pharmacodynamic (PKPD) model for ceftazidime/avibactam against Gram-negative pathogens, with the potential for combination dosage simulation. Methods Four β-lactamase-producing Enterobacteriaceae, covering Ambler classes A, B and D, were exposed to ceftazidime and avibactam, alone and in combination, in static time–kill experiments. A PKPD model was developed and evaluated using internal and external evaluation, and combined with a population PK model and applied in dosage simulations. Results The developed PKPD model included the effects of ceftazidime alone, avibactam alone and an ‘enhancer’ effect of avibactam on ceftazidime in addition to the β-lactamase inhibitory effect of avibactam. The model could describe an extensive external Pseudomonas aeruginosa data set with minor modifications to the enhancer effect, and the utility of the model for clinical dosage simulation was demonstrated by investigating the influence of the addition of avibactam. Conclusions A novel mechanism-based PKPD model for the DBO/β-lactam combination ceftazidime/avibactam was developed that enables future comparison of the effect of avibactam with other DBO/β-lactam inhibitors in simulations, and may be an aid in translating PKPD results from in vitro to animals and humans.

Download Full-text

40 % aq. HF catalyzed three component Synthesis of novel indeno[1,2-b][1,8]naphthyridin-6(11H)-one derivatives and their antimicrobial activity

Letters in Organic Chemistry ◽

10.2174/1570178617666200210112843 ◽

2020 ◽

Vol 17 ◽

Author(s):

Srinu Bhoomandla ◽

Phani Raja Kanuparthy ◽

Rambabu Gundla ◽

Ramana Reddy Bobbala

Keyword(s):

Antimicrobial Activity ◽

Bacillus Subtilis ◽

Candida Albicans ◽

Good Yield ◽

Diffusion Method ◽

Subtilis Strain ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Negative ◽

Aryl Aldehyde

: A Three component Synthesis of novel 5-phenyl-2-(thiophen-2-yl)-4-(trifluoromethyl)-5H-indeno [1,2-b] [1,8] naphthyridin-6(11H)-one derivatives (4a-n) were prepared using 6-phenyl/(thiophen-2-yl)-4-(trifluoromethyl)pyridin-2-amine, 1H-indene-1,3(2H)-dione and aryl aldehyde using 40% aq. HF with good yield. All the synthesized compounds were screened against Gram-positive and Gram-negative bacterial strains and different Candida strains by well diffusion method. Compounds 4c, 4f and 4g showed promising activity on Bacillus subtilis strain and compounds 4c and 4g showed promising activity towards Candida albicans starains.

Download Full-text

Exogenous Production of N-acetylmuramyl-L Alanine Amidase (LysM2) from Siphoviridae Phage Affecting Anti-Gram-Negative Bacteria: Evaluation of Its Structure and Function

Avicenna Journal of Medical Biotechnology ◽

10.18502/ajmb.v14i1.8169 ◽

2022 ◽

Author(s):

Morteza Miri ◽

Sepideh Yazdianpour ◽

Shamsozoha Abolmaali ◽

Shakiba Darvish Alipour Astaneh

Keyword(s):

In Silico ◽

Alpha Helix ◽

Salmonella Typhi ◽

Structure And Function ◽

Gram Negative Bacteria ◽

Gene Encoding ◽

Gram Negative ◽

E Coli ◽

Antigenic Properties ◽

And Function

Background: To obtain endolysin with impact(s) on gram-negative bacteria as well as gram-positive bacteria, N-acetylmuramyl L-alanine-amidase (MurNAc-LAA) from a Bacillus subtilis-hosted Siphoviridae phage (SPP1 phage, Subtilis Phage Pavia 1) was exogenously expressed in Escherichia coli (E. coli). Methods: The sequences of MurNAc-LAA genes encoding peptidoglycan hydrolases were obtained from the Virus-Host database. The sequence of MurNAc-LAA was optimized by GenScript software to generate MurNAc-LAA-MMI (LysM2) for optimal expression in E. coli. Furthermore, the structure and function of LysM2 was evaluated in silico. The optimized gene was synthesized, subcloned in the pET28a, and expressed in E. coli BL21(DE3). The antibacterial effects of the protein on the peptidoglycan substrates were studied. Results: LysM2, on 816 bp gene encoding a 33 kDa protein was confirmed as specific SPP1 phage enzyme. The enzyme is composed of 271 amino acids, with a half-life of 10 hr in E. coli. In silico analyses showed 34.2% alpha-helix in the secondary structure, hydrophobic N-terminal, and lysine-rich C-terminal, and no antigenic properties in LysM2 protein. This optimized endolysin revealed impacts against Proteus (sp) by turbidity, and an antibacterial activity against Klebsiella pneumoniae, Salmonella typhi-murium, and Proteus vulgaris in agar diffusion assays. Conclusion: Taken together, our results confirmed that LysM2 is an inhibiting agent for gram-negative bacteria.

Download Full-text

Green Synthesis of Gold and Silver Nanoparticles by Using Amorphophallus paeoniifolius Tuber Extract and Evaluation of Their Antibacterial Activity

Molecules ◽

10.3390/molecules25204773 ◽

2020 ◽

Vol 25 (20) ◽

pp. 4773

Author(s):

S. M. Abu Nayem ◽

Nasrin Sultana ◽

Md. Aminul Haque ◽

Billal Miah ◽

Md. Mahmodul Hasan ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Green Synthesis ◽

Inhibitory Effect ◽

Reducing Agent ◽

Gram Negative Bacteria ◽

Gold And Silver Nanoparticles ◽

Gram Negative ◽

X Ray ◽

Tuber Extract

In this report, we discussed rapid, facile one-pot green synthesis of gold and silver nanoparticles (AuNPs and AgNPs) by using tuber extract of Amorphophallus paeoniifolius, and evaluated their antibacterial activity. AuNPs and AgNPs were synthesized by mixing their respective precursors (AgNO3 and HAuCl4) with tuber extract of Amorphophallus paeoniifolius as the bio-reducing agent. Characterization of AuNPs and AgNPs were confirmed by applying UV-vis spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDS). From UV-vis characterization, surface plasmon resonance spectra were found at 530 nm for AuNPs and 446 nm for AgNPs. XRD data confirmed that both synthesized nanoparticles were face-centered cubic in crystalline nature, and the average crystallite sizes for the assign peaks were 13.3 nm for AuNPs and 22.48 nm for AgNPs. FTIR data evaluated the characteristic peaks of different phytochemical components of tuber extract, which acted as the reducing agent, and possibly as stabilizing agents. The antibacterial activity of synthesized AuNPs and AgNPs were examined in Muller Hinton agar, against two Gram-positive and four Gram-negative bacteria through the disc diffusion method. AuNPs did not show any inhibitory effect, while AgNPs showed good inhibitory effect against both Gram-positive and Gram-negative bacteria.

Download Full-text