Stable Vesicle Production from Bacterial Total Lipid Extracts

The current study aims to produce stable liposomes from total lipid extracts from bacteria. Liposomes are the small vesicles that are made up of lipids. On their structural basis, they can be considered as simplified cell structure of cell membrane. Structure of liposomes depends on the pH of preparation buffer, method of preparation and the environmental condition in which they are prepared. Liposomes have importance in the field of medicines for diagnostic and therapeutic purposes. They mainly work as a vehicle for drug delivery. The objective of the current study was to make stable liposomes from two types of bacterial samples i.e., a Gram-positive and a Gram-negative strain. E. coli and Bacillus sp. were selected as representative of Gram-negative and Gram-positive bacteria, respectively. Lipid extraction was performed by various methods, out of which the modified Bligh and Dyer method gave most effective results. Liposomes were prepared by extrusion and their stability and efficiency was tested by fluorescence spectrophotometer using OxanolVI. Our results showed that liposomes formed by lipids extracted from E. coli were more stable than the liposomes formed by lipids extracted from Bacillus sp. Keywords: liposomes, Lipids, diagnostic, therapeutic, purposes, fluorescence, Bacillus sp.

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Construction of Leaderless-Bacteriocin-Producing Bacteriophage Targeting E. coli and Neighboring Gram-Positive Pathogens

Microbiology Spectrum ◽

10.1128/spectrum.00141-21 ◽

2021 ◽

Author(s):

Yoshimitsu Masuda ◽

Shun Kawabata ◽

Tatsuya Uedoi ◽

Ken-ichi Honjoh ◽

Takahisa Miyamoto

Keyword(s):

Antimicrobial Agents ◽

Host Strain ◽

Phage Resistance ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

T7 Phage

We demonstrated that we could combine LLB and phage to construct promising novel antimicrobial agents, LLB-phage. The first LLB-phage, lnqQ -T7 phage, can control the growth of both the Gram-negative host strain and neighboring Gram-positive bacteria while preventing the emergence of phage resistance in the host strain.

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Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles for antibacterial photodynamic therapy

Photochemical & Photobiological Sciences ◽

10.1039/c8pp00470f ◽

2019 ◽

Vol 18 (5) ◽

pp. 1147-1155 ◽

Cited By ~ 5

Author(s):

Rehan Khan ◽

Melis Özkan ◽

Aisan Khaligh ◽

Dönüs Tuncel

Keyword(s):

Antibacterial Activity ◽

Photodynamic Therapy ◽

Singlet Oxygen ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Water Dispersible ◽

Gram Positive Bacteria ◽

High Yields

Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles have the ability to generate singlet oxygen in high yields and exhibit light-triggered antibacterial activity against Gram negative bacteria, E. coli as well as Gram positive bacteria, B. subtilis.

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Synthesis and Antibacterial Activity of Chalcones and Pyrimidine-2-ones

E-Journal of Chemistry ◽

10.1155/2005/134830 ◽

2005 ◽

Vol 2 (2) ◽

pp. 109-112

Author(s):

A. K. Parekh ◽

K. K. Desai

Keyword(s):

Antibacterial Activity ◽

Spectral Data ◽

Elemental Analysis ◽

Aromatic Aldehydes ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

H Nmr

Some new chalcones have been prepared by Claisen-schmidt condensation of ketone and different aromatic aldehydes. These chalcones on condensation with urea in presence of acid gave Pyrimidine-2-ones. The synthesized compounds have been characterized by elemental analysis, IR and1H NMR spectral data. They have been screened for their antibacterial activity against Gram positive bacteria B. subtillis & S. aureus and Gram negative bacteria E. coli & S. typhi.

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Bacteriuria in Aids Vs. Urological Patients: Similarities and Differences

Urologia Journal ◽

10.1177/039156039806500415 ◽

1998 ◽

Vol 65 (4) ◽

pp. 547-552

Author(s):

R. Pizzorno ◽

F. Dodi ◽

M. De Mare ◽

G. Diacomanoli ◽

R. Capuzzo ◽

...

Keyword(s):

Urinary Catheter ◽

Urinary Infection ◽

Normal Subjects ◽

Aids Patients ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

Similarities And Differences

The risk of urinary infection is more frequent in AIDS-patients than in normal subjects; it is not yet known if the risk is higher in urological patients. We have studied 394 urine cultures of 242 AIDS-patients (CD4 + < 200 cu. mm), aged from 25 to 52 years (mean=35.1; SD=4.72). Results were analyzed and statistically compared with those obtained in similar studies carried out on AIDS and urological patients. On the whole, 52 urine cultures (13.1%) were positive. Etiology was mainly supported by E. faecalis (Gram-positive) and E. coli (Gram-negative). AIDS patients, without urinary catheter, show a higher risk of urinary infection than normal subjects (P<0.02) but lower than urological patients (P=0.000). An increase in the isolation of Gram-positive bacteria and mycetes in comparison with Gram-negative (already observed in urological patients) has been confirmed. Bacteria isolated in AIDS patients showed variations in sensitivity to usual antibiotics.

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What an Escherichia coli Mutant Can Teach Us About the Antibacterial Effect of Chlorophyllin

Microorganisms ◽

10.3390/microorganisms7020059 ◽

2019 ◽

Vol 7 (2) ◽

pp. 59 ◽

Cited By ~ 11

Author(s):

Marcus Krüger ◽

Peter Richter ◽

Sebastian Strauch ◽

Adeel Nasir ◽

Andreas Burkovski ◽

...

Keyword(s):

Escherichia Coli ◽

Outer Membrane ◽

High Sensitivity ◽

Coli Strain ◽

Photodynamic Treatment ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

Bacterial Model

Due to the increasing development of antibiotic resistances in recent years, scientists search intensely for new methods to control bacteria. Photodynamic treatment with porphyrins such as chlorophyll derivatives is one of the most promising methods to handle bacterial infestation, but their use is dependent on illumination and they seem to be more effective against Gram-positive bacteria than against Gram-negatives. In this study, we tested chlorophyllin against three bacterial model strains, the Gram-positive Bacillus subtilis 168, the Gram-negative Escherichia coli DH5α and E. coli strain NR698 which has a deficient outer membrane, simulating a Gram-negative “without” its outer membrane. Illuminated with a standardized light intensity of 12 mW/cm2, B. subtilis showed high sensitivity already at low chlorophyllin concentrations (≤105 cfu/mL: ≤0.1 mg/L, 106–108 cfu/mL: 0.5 mg/L), whereas E. coli DH5α was less sensitive (≤105 cfu/mL: 2.5 mg/L, 106 cfu/mL: 5 mg/L, 107–108 cfu/mL: ineffective at ≤25 mg/L chlorophyllin). E. coli NR698 was almost as sensitive as B. subtilis against chlorophyllin, pointing out that the outer membrane plays a significant role in protection against photodynamic chlorophyllin impacts. Interestingly, E. coli NR698 and B. subtilis can also be inactivated by chlorophyllin in darkness, indicating a second, light-independent mode of action. Thus, chlorophyllin seems to be more than a photosensitizer, and a promising substance for the control of bacteria, which deserves further investigation.

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Anti-Bacteria Behaviors of TaN-Cu and TaN-Ag Nanocomposite Thin Films

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.66.142 ◽

2010 ◽

Vol 66 ◽

pp. 142-149 ◽

Cited By ~ 5

Author(s):

Jang Hsing Hsieh ◽

T.H. Yeh ◽

C.S. Chiou ◽

C.T. Huang ◽

C. Li

Keyword(s):

Film Surface ◽

Nanocomposite Films ◽

Metal Particles ◽

Buffer Solution ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Ion Concentrations ◽

Gram Positive Bacteria ◽

Nanocomposite Thin Films

TaN–Cu and TaN-Ag nanocomposite films were deposited by reactive co-sputtering on Si. The films were then annealed using RTA (Rapid Thermal Annealing) at 400 °C for 2, 4, 8, 15 minutes respectively to induce the nucleation and growth of metal particles in TaN matrix and on film surface. The samples were then tested for their anti-bacterial behaviors against Gram-negative and Gram-positive bacteria. The results were compared with the solubility of Ag and Cu in a buffer solution. Under similar ion concentrations, it is concluded that Ag ion or TaN-Ag is more effective against E. Coli (Gram-negative), while Cu ion or TaN-Cu is more effective against Staphylococcus aureus (Gram-positive).

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Vpliv vrste povzročitelja na porast koncentracije prokalcitonina pri bolnikih s sepso

Slovenian Medical Journal ◽

10.6016/zdravvestn.1120 ◽

2015 ◽

Vol 84 (2) ◽

Author(s):

Sara Jereb ◽

Natalija Planinc Strunjaš ◽

Matjaž Jereb

Keyword(s):

Causative Agent ◽

Antimicrobial Therapy ◽

Statistical Evaluation ◽

Prognostic Biomarker ◽

Blood Collection ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

Clinical Center

AbstractTheoretical background: Procalcitonin (PCT) is diagnostic and prognostic biomarker of sepsis. The objective of this study was to evaluate the correlation between sepsis causative agent and serum PCT concentration, since it would influence the initial empirical antimicrobial therapy selection.Methods: This retrospective study included 96 patients with sepsis who were admitted to Intensive Care Unit of Department of Infectious Diseases and Febrile Illnesses of University Clinical Center Ljubljana from September of 2011 through March of 2013. Sepsis was established clinically and defined aetiologically by haemoculture growth. Statistical evaluation was conducted in 76 patients who had not received proper antimicrobial therapy prior to blood collection. ForPCT determination imunoluminometric method was used and concentrations above 5 mg/L were considered elevated. Results: Serum PCT concentration was significantly higher in Gram-negative sepsis (PCT median was 26,3 μg/L) compared to Gram-positive sepsis (PCT median was 11,2 μg/L) (p = 0,016). Differences in PCT concentrations between Gram-positive pathogens were not statistically significant (p = 0,09), however, S. aureus sepsis is linked to higher serum PCT concentration (median PCT 12,8 μg/L) than all other Gram-positive agents put together (median PCT of 5,9 μg/L) (p = 0,016). Difference in PCT concentration in E. coli sepsis (median PCT of 38,2 μg/L) compared to other enterobacteria (median PCT of 26,3 μg/L) is not statistically significant (p = 0,902). Conclusions: Causative agent has a significant effect on serum PCT concentration in patients with sepsis. Higher values were present in Gram-negative than in Gram-positive sepsis. Amongst Gram-positive pathogens, S. aureus caused greater rise in PCT than other Gram-positive bacteria put together.

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Microbiological Profile and Antibiotic Sensitivity Pattern of Bacteria in Diabetic Foot Ulcers in a Tertiary Care Hospital

Journal of Advanced Research in Medicine ◽

10.24321/2349.7181.202101 ◽

2021 ◽

Vol 08 (01) ◽

pp. 1-8

Author(s):

Gajender Singh Ranga ◽

Keyword(s):

Diabetic Foot ◽

Tertiary Care ◽

Klebsiella Pneumonia ◽

Care Hospital ◽

Gram Positive ◽

Cross Sectional ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

Sensitivity Pattern

Introduction: Diabetic foot is any foot pathology due to diabetes or sequelae of diabetes mellitus. This study was conducted to identify the common microorganisms isolated from diabetic foot and to analyse the antibiotic susceptibility pattern of bacteria isolated from diabetic foot. Materials and Method: The study was a hospital based cross-sectional study where 146 foot ulcer samples (who had type 2 diabetes) were analysed. Swabs were collected from the edge and margins of ulcers, and organisms were identified by gram staining culture and biochemical reactions. Result:Out of 146 patients, 69 specimens showed growth of organisms. Total 84 aerobic organisms were isolated and out of them, 64 cases showed bacterial growth, in which 84 bacteria were isolated, which represented an average of 1.28 organisms per case. Among these organisms, 62 gram-negative and 22 gram-positive organisms were isolated. E. coli was the most common gram-negative isolate (23.81%), followed by Pseudomonas aeruginosa (21.4%), and Klebsiella pneumonia(8.33%), while among gram-positive bacteria, S. aureus was the most common isolate (22.6%). Conclusion: Incidence of growth was 47.2% in which E. coli (23.8%) was the most common isolate. Gram-negative bacteria were more common than gram-positive bacteria. Diabetic foot infections are polymicrobial in nature.

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A Novel Mobilizing Tool Based on the Conjugative Transfer System of the IncM Plasmid pCTX-M3

Applied and Environmental Microbiology ◽

10.1128/aem.01205-20 ◽

2020 ◽

Vol 86 (17) ◽

Author(s):

Michał Dmowski ◽

Izabela Kern-Zdanowicz

Keyword(s):

Bacillus Subtilis ◽

Lactococcus Lactis ◽

Conjugative Transfer ◽

Conjugation System ◽

Gram Positive ◽

Gram Negative ◽

Content Type ◽

E Coli ◽

Gram Positive Bacteria ◽

Mobilizable Plasmid

ABSTRACT Conjugative plasmids are the main players in horizontal gene transfer in Gram-negative bacteria. DNA transfer tools constructed on the basis of such plasmids enable gene manipulation even in strains of clinical or environmental origin, which are often difficult to work with. The conjugation system of the IncM plasmid pCTX-M3 isolated from a clinical strain of Citrobacter freundii has been shown to enable efficient mobilization of oriTpCTX-M3-bearing plasmids into a broad range of hosts comprising Alpha-, Beta-, and Gammaproteobacteria. We constructed a helper plasmid, pMOBS, mediating such mobilization with an efficiency up to 1,000-fold higher than that achieved with native pCTX-M3. We also constructed Escherichia coli donor strains with chromosome-integrated conjugative transfer genes: S14 and S15, devoid of one putative regulator (orf35) of the pCTX-M3 tra genes, and S25 and S26, devoid of two putative regulators (orf35 and orf36) of the pCTX-M3 tra genes. Strains S14 and S15 and strains S25 and S26 are, respectively, up to 100 and 1,000 times more efficient in mobilization than pCTX-M3. Moreover, they also enable plasmid mobilization into the Gram-positive bacteria Bacillus subtilis and Lactococcus lactis. Additionally, the constructed E. coli strains carried no antibiotic resistance genes that are present in pCTX-M3 to facilitate manipulations with antibiotic-resistant recipient strains, such as those of clinical origin. To demonstrate possible application of the constructed tool, an antibacterial conjugation-based system was designed. Strain S26 was used for introduction of a mobilizable plasmid coding for a toxin, resulting in the elimination of over 90% of recipient E. coli cells. IMPORTANCE The conjugation of donor and recipient bacterial cells resulting in conjugative transfer of mobilizable plasmids is the preferred method enabling the introduction of DNA into strains for which other transfer methods are difficult to establish (e.g., clinical strains). We have constructed E. coli strains carrying the conjugation system of the IncM plasmid pCTX-M3 integrated into the chromosome. To increase the mobilization efficiency up to 1,000-fold, two putative regulators of this system, orf35 and orf36, were disabled. The constructed strains broaden the repertoire of tools for the introduction of DNA into the Gram-negative Alpha-, Beta-, and Gammaproteobacteria, as well as into Gram-positive bacteria such as Bacillus subtilis and Lactococcus lactis. The antibacterial procedure based on conjugation with the use of the orf35- and orf36-deficient strain lowered the recipient cell number by over 90% owing to the mobilizable plasmid-encoded toxin.

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Antibacterial Activity and Chemical Composition of Red Peacock Flower (Caesalpinia pulcherrima L.) Leaf Essential Oil

Jurnal Kimia Sains dan Aplikasi ◽

10.14710/jksa.22.6.269-274 ◽

2019 ◽

Vol 22 (6) ◽

pp. 269-274

Author(s):

Novena Risnalani Rintank Constani ◽

Hartati Soetjipto ◽

Sri Hartini

Keyword(s):

Antibacterial Activity ◽

Essential Oil ◽

Essential Oils ◽

Inhibition Zone ◽

Diffusion Method ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

Leaf Essential Oil

Peacock flower (Caesalpinia pulcherrima L.) leaves contain essential oils which can be used as an ingredient in cosmetics, perfume, aromatherapy, medicine, and supplements. The study was conducted to obtain essential oils from peacock flower leaves and determine the antibacterial activity against gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa). Antibacterial activity test was carried out by the agar diffusion method, using paper discs. Measurements were made for the inhibition zone diameter (IZD) that appeared, while the essential oil component was analyzed using GC-MS. The results showed that the peacock flower leaves (C. pulcherrima) had a moderate to strong antibacterial effect at a concentration of 7.5%-20% against gram-positive bacteria (B. subtilis and S. aureus) and gram-negative bacteria (E. coli and P. aeruginosa). Gram-negative E. coli bacteria are relatively more sensitive to peacock flower leaf essential oil compared to other test bacteria. Peacock flower (C. pulcherrima) leaf essential oil is composed of 7 main components namely β-Cubebene 33.87%; Caryophyllene 23.00%; γ-Elemene 13.18%; α-Pinene 10.96%; Cadina-1(10),4-diene 10.20%; Copaene; 7.09%; β-Pinene 1.70%.

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