Isolation of Persister Cells of Bacillus subtilis and Determination of Their Susceptibility to Antimicrobial Peptides

Persister cells are growth-arrested subpopulations that can survive possible fatal environments and revert to wild types after stress removal. Clinically, persistent pathogens play a key role in antibiotic therapy failure, as well as chronic, recurrent, and antibiotic-resilient infections. In general, molecular and physiological research on persister cells formation and compounds against persister cells are much desired. In this study, we firstly demonstrated that the spore forming Gram-positive model organism Bacillus subtilis can be used to generate persister cells during exposure to antimicrobial compounds. Interestingly, instead of exhibiting a unified antibiotic tolerance profile, different number of persister cells and spores were quantified in various stress conditions. qPCR results also indicated that differential stress responses are related to persister formation in various environmental conditions. We propose, for the first time to the best of our knowledge, an effective method to isolate B. subtilis persister cells from a population using fluorescence-activated cell sorting (FACS), which makes analyzing persister populations feasible. Finally, we show that alpha-helical cationic antimicrobial peptides SAAP-148 and TC-19, derived from human cathelicidin LL-37 and human thrombocidin-1, respectively, have high efficiency against both B. subtilis vegetative cells and persisters, causing membrane permeability and fluidity alteration. In addition, we confirm that in contrast to persister cells, dormant B. subtilis spores are not susceptible to the antimicrobial peptides.

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Cationic antimicrobial peptides elicit a complex stress response in Bacillus subtilis that involves ECF-type sigma factors and two-component signal transduction systems

Microbiology ◽

10.1099/mic.0.27761-0 ◽

2005 ◽

Vol 151 (5) ◽

pp. 1577-1592 ◽

Cited By ~ 103

Author(s):

Milla Pietiäinen ◽

Marika Gardemeister ◽

Maria Mecklin ◽

Soile Leskelä ◽

Matti Sarvas ◽

...

Keyword(s):

Signal Transduction ◽

Bacillus Subtilis ◽

Antimicrobial Peptides ◽

Stress Responses ◽

Signal Transduction Pathways ◽

Synthetic Analogue ◽

Cationic Antimicrobial Peptides ◽

Component Systems ◽

Two Component ◽

Two Component Systems

Stress responses of Bacillus subtilis to membrane-active cationic antimicrobial peptides were studied. Global analysis of gene expression by DNA macroarray showed that peptides at a subinhibitory concentration activated numerous genes. A prominent pattern was the activation of two extracytoplasmic function sigma factor regulons, SigW and SigM. Two natural antimicrobial peptides, LL-37 and PG-1, were weak activators of SigW regulon genes, whereas their synthetic analogue poly-l-lysine was clearly a stronger activator of SigW. It was demonstrated for the first time that LL-37 is a strong and specific activator of the YxdJK two-component systems, one of the three highly homologous two-component systems sensing antimicrobial compounds. YxdJK regulates the expression of the YxdLM ABC transporter. The LiaRS (YvqCE) TCS was also strongly activated by LL-37, but its activation is not LL-37 specific, as was demonstrated by its activation with PG-1 and Triton X-100. Other strongly LL-37-induced genes included yrhH and yhcGHI. Taken together, the responses to cationic antimicrobial peptides revealed highly complex regulatory patterns and induction of several signal transduction pathways. The results suggest significant overlap between different stress regulons and interdependence of signal transduction pathways mediating stress responses.

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Determination of antimicrobial activity of extracts from Melissa officinalis L.

Bulletin of the Karaganda University. “Biology, medicine, geography Series” ◽

10.31489/2020bmg4/79-84 ◽

2020 ◽

Vol 100 (4) ◽

pp. 79-84

Author(s):

Nargiz Seidalina ◽

◽

Saule Ahmetova ◽

Marlen Smagulov ◽

Gayane Аtazhanova ◽

...

Keyword(s):

Antimicrobial Activity ◽

Bacillus Subtilis ◽

Water Extract ◽

Antimicrobial Effect ◽

Antimicrobial Drugs ◽

Gram Positive Bacteria ◽

Weak Activity ◽

First Time ◽

Yeast Fungus

The constant growth of antibiotic resistance of bacteria creates the need for the development of antimicrobial drugs from extracts of medicinal plants. For the first time, the article presents the results of antimicrobial activity of extracts of Melissa officinallis L. (drug melissa) obtained by various methods, including ultrasonic extraction. The antimicrobial activity of the samples was studied in relation to strains of gram-positive bacteria Staphylocococus aureus, Bacillus subtilis, gram-negative strains Escherichia coli and yeast fungus Candida albicans. It was found that samples of aqueous extracts of drug melissa obtained by infusion and extraction by ultrasound have a pronounced antimicrobial effect on Staphylococus aureus, ultrasonic extracts of 30 % — and 90 % — alcohol extracts and water extract are active on Staphylocococus aureus and Bacillus subtilis and all samples showed weak activity The obtained data can be used for development of new phytopreparations with expressed antimicrobial activity.

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368. A High Efficiency Diffusive Sampler for the Determination of Aldehydes and Ketones in Ambient and Indoor Air

10.3320/1.2763718 ◽

2000 ◽

Author(s):

S. Uchiyama ◽

I. DeGraff ◽

T. Kaneko

Keyword(s):

Indoor Air ◽

High Efficiency ◽

Diffusive Sampler ◽

Aldehydes And Ketones

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Disability as a social phenomenon

10.33920/med-03-2007-01 ◽

2020 ◽

pp. 22-38

Author(s):

Natalia Guseva ◽

Vitaliy Berdutin

Keyword(s):

Social Protection ◽

Russian Society ◽

Stage Model ◽

High Quality ◽

Rehabilitation Programs ◽

Current State ◽

The Social ◽

Consistent Solution ◽

First Time

At present, the problem of establishing disability is a point at issue in Russia. Despite the fact that medical criteria for disability are being developed very actively, high-quality methods for assessing social hallmarks are still lacking. Since disability is a phenomenon inherent in any society, each state forms a social and economic policy for people with disabilities in accordance with its level of development, priorities and opportunities. We have proposed a three-stage model, which includes a system for the consistent solution of the main tasks aimed at studying the causes and consequences of the problems encountered today in the social protection of citizens with health problems. The article shows why the existing approaches to the determination of disability and rehabilitation programs do not correspond to the current state of Russian society and why a decrease in the rate of persons recognized as disabled for the first time does not indicate an improvement in the health of the population. The authors proposed a number of measures with a view to correcting the situation according to the results of the study.

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Phytochemical Constituents of Annona reticulata and their Cytotoxic Activity

Letters in Organic Chemistry ◽

10.2174/1570178616666190724123004 ◽

2020 ◽

Vol 17 (3) ◽

pp. 206-210

Author(s):

Ty Viet Pham ◽

Thang Quoc Le ◽

Anh Tuan Le ◽

Hung Quoc Vo ◽

Duc Viet Ho

Keyword(s):

Cytotoxic Activity ◽

Cell Lines ◽

Structural Determination ◽

Phytochemical Investigation ◽

Ic50 Values ◽

Phytochemical Constituents ◽

First Time ◽

Annona Reticulata

A phytochemical investigation of the leaves of Annona reticulata led to the isolation and structural determination of β-sitosterol (1), ent-pimara-8(14),15-dien-19-oic acid (2), ent-pimara- 8(14),15-dien-19-ol (3), quercetin (4), quercetin 3-O-α-L-arabinopyranoside (5), and a mixture of quercetin 3-O-β-D-galactopyranoside (6a) and quercetin 3-O-β-D-glucopyranoside (6b). Of these, compounds 2 and 3 were isolated from the genus Annona for the first time. Compound 3 showed strong cytotoxicity against SK-LU-1 and SW626 cell lines with IC50 values of 17.64 ± 1.07 and 19.79 ± 1.41 μg mL-1, respectively.

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Development of an HPLC-UV Method for Quantification of Stattic

Current Pharmaceutical Analysis ◽

10.2174/1573412914666180523092957 ◽

2019 ◽

Vol 15 (6) ◽

pp. 568-573

Author(s):

Soheil Sedaghat ◽

Ommoleila Molavi ◽

Akram Faridi ◽

Ali Shayanfar ◽

Mohammad Reza Rashidi

Keyword(s):

High Performance ◽

Accurate Method ◽

Plasma Samples ◽

Promising Target ◽

Relative Standard ◽

Dimerization Inhibitor ◽

Oncogenic Protein ◽

First Time ◽

Transcription 3

Background: Signal transducer and activator of transcription 3 (STAT3), an oncogenic protein found constitutively active in many types of human malignancies, is considered to be a promising target for cancer therapy. Objective: In this study for the first time, a simple and accurate method has been developed for the determination of a STAT3 dimerization inhibitor called stattic in aqueous and plasma samples. Methods: A reverse-phase high-performance liquid chromatography (RP-HPLC) composed of C18 column as stationary phase, and the mixture of acetonitrile (60%) and water (40%) as mobile phase with a UV detection at 215 nm were applied for quantification of stattic. The developed method was validated by Food and Drug Administration (FDA) guideline. Results: The method provided a linear range between 1-40 and 2.5-40 µg mL-1 for aqueous and plasma samples, respectively, with a correlation coefficient of 0.999. The accuracy (as recovery) of the developed method was found to be between 95-105% for aqueous medium and 85-115% for plasma samples. The precision (as relative standard deviation) for aqueous and plasma samples was less than 6% and 15%, respectively. The sensitivity of the developed method based on FDA guideline was 1 µg mL-1 for aqueous and 2.5 µg mL-1 for plasma samples. Conclusion: These results show that the established method is a fast and accurate quantification for stattic in aqueous and plasma samples.

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Determination of cleavage sites of APendonuclease from Bacillus subtilis.

Agricultural and Biological Chemistry ◽

10.1271/bbb1961.44.1713 ◽

1980 ◽

Vol 44 (7) ◽

pp. 1713-1715

Author(s):

Yoshihiko SAKO ◽

Aritsune UCHIDA ◽

Hajime KADOTA

Keyword(s):

Bacillus Subtilis ◽

Cleavage Sites

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Carbon dots derived from Fusobacterium nucleatum for intracellular determination of Fe3+ and bioimaging both in vitro and in vivo

Analytical Methods ◽

10.1039/d1ay00020a ◽

2021 ◽

Author(s):

Lijuan Liu ◽

Shengting Zhang ◽

Xiaodan Zheng ◽

Hongmei Li ◽

Qi Chen ◽

...

Keyword(s):

Carbon Dots ◽

Fusobacterium Nucleatum ◽

Living Cells ◽

First Time ◽

Fluorescent Carbon Dots ◽

Fluorescent Carbon

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.

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Experimental investigation to characterize simple versus multi scaling analysis of hydraulic conductivity at a mesoscale

Stochastic Environmental Research and Risk Assessment ◽

10.1007/s00477-021-02079-w ◽

2021 ◽

Author(s):

Guglielmo Federico Antonio Brunetti ◽

Samuele De Bartolo ◽

Carmine Fallico ◽

Ferdinando Frega ◽

Maria Fernanda Rivera Velásquez ◽

...

Keyword(s):

Hydraulic Conductivity ◽

Spatial Variability ◽

Hydraulic Properties ◽

Scaling Laws ◽

Scaling Analysis ◽

Field Scale ◽

Porous Formation ◽

Proper Design ◽

First Time

AbstractThe spatial variability of the aquifers' hydraulic properties can be satisfactorily described by means of scaling laws. The latter enable one to relate the small (typically laboratory) scale to the larger (typically formation/regional) ones, therefore leading de facto to an upscaling procedure. In the present study, we are concerned with the spatial variability of the hydraulic conductivity K into a strongly heterogeneous porous formation. A strategy, allowing one to identify correctly the single/multiple scaling of K, is applied for the first time to a large caisson, where the medium was packed. In particular, we show how to identify the various scaling ranges with special emphasis on the determination of the related cut-off limits. Finally, we illustrate how the heterogeneity enhances with the increasing scale of observation, by identifying the proper law accounting for the transition from the laboratory to the field scale. Results of the present study are of paramount utility for the proper design of pumping tests in formations where the degree of spatial variability of the hydraulic conductivity does not allow regarding them as “weakly heterogeneous”, as well as for the study of dispersion mechanisms.

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