scholarly journals Poly[2-(dimethylamino)ethyl methacrylate-co-ethylene dimethacrylate]nanogel by dispersion polymerization for inhibition of pathogenic bacteria

RSC Advances ◽  
2021 ◽  
Vol 11 (53) ◽  
pp. 33461-33470
Author(s):  
Petr Šálek ◽  
Jiří Trousil ◽  
Jitka Nováčková ◽  
Jiřina Hromádková ◽  
Andrii Mahun ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Acinetobacter Baumannii ◽  
Pathogenic Bacteria ◽  
Dispersion Polymerization ◽  
Ethyl Methacrylate ◽  
Ethylene Dimethacrylate

Quaternized 167 nm poly[2-(dimethylamino)ethyl methacrylate-co-ethylene dimethacrylate] nanogel by dispersion polymerization in water/2-methoxyethanol medium induced death of pathogenic Staphylococcus aureus and Acinetobacter baumannii.

scholarly journals Light Modulates Important Pathogenic Determinants and Virulence in Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus ESKAPE Pathogens

2020 ◽  
Author(s):  
M. R. Tuttobene ◽  
J. F. Pérez ◽  
E. Pavesi ◽  
B. Perez Mora ◽  
D. Biancotti ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogens ◽  
General Concept ◽  
Infection Model ◽  
Type Vi Secretion System ◽  
Sense And Respond ◽  
Human Infections

Light sensing has been extensively characterized in the human pathogen Acinetobacter baumannii at environmental temperatures. However, the influence of light on the physiology and pathogenicity of human bacterial pathogens at temperatures found in warm-blooded hosts is still poorly understand. In this work, we show that ESKAPE priority pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter spp., which have been recognized by the WHO and the CDC as critical, can also sense and respond to light at temperatures found in human hosts. Most interestingly, in these pathogens light modulates important pathogenicity determinants as well as virulence in an epithelial infection model, which could have implications in human infections. In fact, we found that alpha-toxin-dependent hemolysis, motility and growth under iron deprived conditions are modulated by light in S. aureus. Light also regulates persistence, metabolism and the ability to kill competitors, in some of these microorganisms. Finally, light exerts a profound effect on the virulence of these pathogens in an epithelial infection model, though the response is not the same in the different species: virulence was enhanced by light in A. baumannii and S. aureus, while in A. nosocomialis and P. aeruginosa it was reduced. Neither the BlsA photoreceptor nor the type VI secretion system (T6SS) are involved in virulence modulation by light in A. baumannii. Overall, this fundamental knowledge highlights the potential use of light to control pathogen's virulence, either directly or by manipulating the light regulatory switch toward the lowest virulence/persistence configuration. IMPORTANCE Pathogenic bacteria are microorganisms capable of producing disease. Dangerous bacterial pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii are responsible for serious intrahospital and community infections in humans. Therapeutics is often complicated due to resistance to multiple antibiotics, rendering them ineffective. In this work, we show that these pathogens sense natural light and respond to it by modulating aspects related to their ability to cause disease: in the presence of light some of them become more aggressive while others show an opposite response. Overall, we provide new understanding on the behavior of these pathogens, which could contribute to control infections caused by them. Since the response is distributed in diverse pathogens, this notion could prove a general concept.

scholarly journals Camellia sinensis (Green Tea) Mediated Synthesis of Zinc Oxide Nanoparticles and Detect its Antibacterial Activity against Escherichia coli, Staphylococcus aureus and Acinetobacter baumannii

2017 ◽  
Vol 11 (1) ◽  
pp. 34-40
Author(s):  
Israa Ali Zaidan Al-Ogaidi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Acinetobacter Baumannii ◽  
Green Tea ◽  
Zno Nanoparticles ◽  
Zinc Oxide Nanoparticles ◽  
Pathogenic Bacteria ◽  
Oxide Nanoparticles

In the current study, synthesis and characterization of Zinc oxide nanoparticles (ZnONPs) and its application as anti-pathogenic bacteria were investigated.  ZnO which has been prepared by using aqueous of green tea leaves extract (Camellia sinensis) as a reducing agent. The wavelength range was measured by Ultraviolet–visible spectroscopy (UV-Vis) for monitoring the formation of the nanoparticles, which showed sharp peak at 360 nm. The average size and shape of the nanoparticles were detected by using Atomic Force Microscopy (AFM) which was 88 nm with spherical shape. Fourier transform–infrared (FTIR). FT-IR spectra was documented for the ZnO nanoparticles synthesized by green tea extract to detect the biomolecules involved in the synthesis process. The antibacterial activity of crystal Zinc Oxide (ZnO) nanoparticles was explored against pathogenic bacteria that included Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii. The antibacterial test was conducted in solid media using different concentrations of ZnO and disk diffusion method, 100 µg/ml presented the best antibacterial activity, and further studies on the damage of bacterial genomic DNA of Escherichia coli and Acinetobacter baumannii were carried out using gel electrophoresis exposed the DNA fragment bands, this activity may be caused by the interactions between the surface charge of cell and nanoparticles. Reactive oxygen species (ROS) properties of the particles might disturb cell wall and great antimicrobial action

scholarly journals Structural basis of inhibition of a transporter from Staphylococcus aureus, NorC, through a single-domain camelid antibody

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sushant Kumar ◽  
Arunabh Athreya ◽  
Ashutosh Gulati ◽  
Rahul Mony Nair ◽  
Ithayaraja Mahendran ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Major Facilitator Superfamily ◽  
Single Domain ◽  
Fluoroquinolone Resistance ◽  
Structural Basis ◽  
Antibody Complex ◽  
Complementarity Determining Regions ◽  
Major Facilitator ◽  
Alternating Access

AbstractTransporters play vital roles in acquiring antimicrobial resistance among pathogenic bacteria. In this study, we report the X-ray structure of NorC, a 14-transmembrane major facilitator superfamily member that is implicated in fluoroquinolone resistance in drug-resistant Staphylococcus aureus strains, at a resolution of 3.6 Å. The NorC structure was determined in complex with a single-domain camelid antibody that interacts at the extracellular face of the transporter and stabilizes it in an outward-open conformation. The complementarity determining regions of the antibody enter and block solvent access to the interior of the vestibule, thereby inhibiting alternating-access. NorC specifically interacts with an organic cation, tetraphenylphosphonium, although it does not demonstrate an ability to transport it. The interaction is compromised in the presence of NorC-antibody complex, consequently establishing a strategy to detect and block NorC and related transporters through the use of single-domain camelid antibodies.

scholarly journals Antimicrobial Efficacy and Spectrum of Phosphorous-Fluorine Co-Doped TiO2 Nanoparticles on the Foodborne Pathogenic Bacteria Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
György Schneider ◽  
Bettina Schweitzer ◽  
Anita Steinbach ◽  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Campylobacter Jejuni ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Tio2 Nps ◽  
E Coli ◽  
Foodborne Pathogenic Bacteria ◽  
And Staphylococcus Aureus ◽  
Co Doped

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO2 nanoparticles (PF-TiO2) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO2 NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO2 NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO2/3 h and PF-TiO2/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~106 by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO2/1 h and PF-TiO2/12 h NPs was lower, typically causing a ~2–4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO2/0 h was comparable to P25 TiO2, a commercial TiO2 with high photocatalytic activity. Our results show that PF-co-doping of TiO2 NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.

scholarly journals Bodipy-Loaded Micelles Based on Polylactide as Surface Coating for Photodynamic Control of Staphylococcus aureus

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 223
Author(s):  
Enrico Caruso ◽  
Viviana Teresa Orlandi ◽  
Miryam Chiara Malacarne ◽  
Eleonora Martegani ◽  
Chiara Scanferla ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Surface Coatings ◽  
Supramolecular System ◽  
Amphiphilic Copolymers ◽  
Oxygen Penetration ◽  
Short Period ◽  
Excellent Activity ◽  
Coating Matrix ◽  
Photodynamic Control

Decontaminating coating systems (DCSs) represent a challenge against pathogenic bacteria that may colonize hospital surfaces, causing several important infections. In this respect, surface coatings comprising photosensitizers (PSs) are promising but still controversial for several limitations. PSs act through a mechanism of antimicrobial photodynamic inactivation (aPDI) due to formation of reactive oxygen species (ROS) after light irradiation. However, ROS are partially deactivated during their diffusion through a coating matrix; moreover, coatings should allow oxygen penetration that in contact with the activated PS would generate 1O2, an active specie against bacteria. In the attempt to circumvent such constraints, we report a spray DCS made of micelles loaded with a PS belonging to the BODIPY family (2,6-diiodo-1,3,5,7-tetramethyl-8-(2,6-dichlorophenyl)-4,4′-difluoroboradiazaindacene) that is released in a controlled manner and then activated outside the coating. For this aim, we synthesized several amphiphilic copolymers (mPEG–(PLA)n), which form micelles, and established the most stable supramolecular system in terms of critical micelle concentration (CMC) and ∆Gf values. We found that micelles obtained from mPEG–(PLLA)2 were the most thermodynamically stable and able to release BODIPY in a relatively short period of time (about 80% in 6 h). Interestingly, the BODIPY released showed excellent activity against Staphylococcus aureus even at micromolar concentrations.

scholarly journals Staphylococcus aureus Serves as an Iron Source for Pseudomonas aeruginosa during In Vivo Coculture

2005 ◽  
Vol 187 (2) ◽  
pp. 554-566 ◽  
Author(s):  
Lauren M. Mashburn ◽  
Amy M. Jett ◽  
Darrin R. Akins ◽  
Marvin Whiteley
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Iron Acquisition ◽  
Low Oxygen ◽  
Dialysis Membrane ◽  
Opportunistic Human Pathogen ◽  
The Impact

ABSTRACT Pseudomonas aeruginosa is a gram-negative opportunistic human pathogen often infecting the lungs of individuals with the heritable disease cystic fibrosis and the peritoneum of individuals undergoing continuous ambulatory peritoneal dialysis. Often these infections are not caused by colonization with P. aeruginosa alone but instead by a consortium of pathogenic bacteria. Little is known about growth and persistence of P. aeruginosa in vivo, and less is known about the impact of coinfecting bacteria on P. aeruginosa pathogenesis and physiology. In this study, a rat dialysis membrane peritoneal model was used to evaluate the in vivo transcriptome of P. aeruginosa in monoculture and in coculture with Staphylococcus aureus. Monoculture results indicate that approximately 5% of all P. aeruginosa genes are differentially regulated during growth in vivo compared to in vitro controls. Included in this analysis are genes important for iron acquisition and growth in low-oxygen environments. The presence of S. aureus caused decreased transcription of P. aeruginosa iron-regulated genes during in vivo coculture, indicating that the presence of S. aureus increases usable iron for P. aeruginosa in this environment. We propose a model where P. aeruginosa lyses S. aureus and uses released iron for growth in low-iron environments.

scholarly journals Measurement of Effects of Antibiotics in Bioluminescent Staphylococcus aureus RN4220

2001 ◽  
Vol 45 (12) ◽  
pp. 3456-3461 ◽  
Author(s):  
Mervi Tenhami ◽  
Kaisa Hakkila ◽  
Matti Karp
Keyword(s):  
Staphylococcus Aureus ◽  
High Throughput Screening ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Light Emission ◽  
Detection System ◽  
Firefly Luciferase ◽  
Luciferase Reporter ◽  
Luciferase Expression ◽  
Luciferase Reporter Gene

ABSTRACT The spread of antibiotic resistance among pathogenic bacteria is a serious threat to humans and animals. Therefore, unnecessary use should be minimized, and new antimicrobial agents with novel mechanisms of action are needed. We have developed an efficient method for measuring the action of antibiotics which is applied to a gram-positive strain,Staphylococcus aureus RN4220. The method utilizes the firefly luciferase reporter gene coupled to the metal-induciblecadA promoter in a plasmid, pTOO24. Correctly timed induction by micromolar concentrations of antimonite rapidly triggers the luciferase gene transcription and translation. This sensitizes the detection system to the action of antibiotics, and especially for transcriptional and translational inhibitors. We show the results for 11 model antibiotics with the present approach and compare them to an analytical setup with a strain where luciferase expression is under the regulation of a constitutive promoter giving only a report of metabolic inhibition. The measurement of light emission from intact living cells is shown to correlate extremely well (r = 0.99) with the conventional overnight growth inhibition measurement. Four of the antibiotics were within a 20% concentration range and four were within a 60% concentration range of the drugs tested. This approach shortens the assay time needed, and it can be performed in 1 to 4 h, depending on the sensitivity needed. Furthermore, the assay can be automatized for high-throughput screening by the pharmaceutical industry.

Recovery efficiency of two glove-sampling methods

2021 ◽  
pp. 1-3
Author(s):  
Amanda K. Lyons ◽  
Laura J. Rose ◽  
Judith Noble-Wang
Keyword(s):  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Sampling Methods ◽  
Recovery Efficiency ◽  
Methicillin Resistant

Abstract Two methods to sample pathogens from gloved hands were compared: direct imprint onto agar and a sponge-wipe method. The sponge method was significantly better at recovering Clostridiodes difficile spores, and no difference was observed between the methods at 101 inoculum for carbapenemase-producing KPC+ Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii.

scholarly journals Identification and antibiogram study of bacterial species isolated from milk samples of different locations in Bangladesh

2016 ◽  
Vol 1 (3) ◽  
pp. 457-462 ◽  
Author(s):  
Md Nuruzzaman Munsi ◽  
Nathu Ram Sarker ◽  
Razia Khatun ◽  
Mohammed Khorshed Alam
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Public Health Importance ◽  
Milk Samples ◽  
First Choice

Cow’s milk containing pathogenic bacteria is an important threat to the consumers. The objectives of the present study were to identify the bacterial agents of public health importance in milk samples (n=35) of different locations and to determine their sensitivity to different antibiotics. The milk samples were collected and transported aseptically and subsequently allowed for culture in bacteriological media, Gram’s staining and biochemical tests for the identification of bacterial species. The bacteria identified were Staphylococcus aureus, Escherichia coli and Salmonella typhi, and their prevalence, in case of vendor milk specimens (n=28), were 96.43%, 53.57% and 35.71% respectively, and of brand milk specimens (n=7), were 42.86 %, 28.57% and 0%, respectively. This suggests that cautionary measures should be taken for quality milk production and consumption. The antibiotic sensitivity test was done by disc diffusion method and the average inhibition zones, in case of Staphylococcus aureus, were 32 mm for oxytetracycline, 26 mm for amoxicillin, 35 mm for ciprofloxacin, 27 mm for cefotaxime, 30 mm for ceftriaxone, 30 mm for azithromycin, and 26 mm for erythromycin; in case of Escherichia coli, were 5 mm for oxytetracycline, 9 mm for amoxicillin, 22 mm for ciprofloxacin, 30 mm for cefotaxime, 31 mm for ceftriaxone, 15 mm for azithromycin, and 0 mm for erythromycin; in case of Salmonella typhi., were 25 mm for oxytetracycline, 24 mm for amoxicillin, 38 mm for ciprofloxacin, 31 mm for cefotaxime, 34 mm for ceftriaxone, 24 mm for azithromycin, and 0 mm for erythromycin. Therefore, ciprofloxacin and ceftriaxone may be the antibiotics of first choice, and cefotaxime and azithromycin may be the second choice among the test antibiotics for the treatment of illness caused by these bacteria.Asian J. Med. Biol. Res. December 2015, 1(3): 457-462

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