scholarly journals Impact of Biosynthesized Silver Nanoparticles on Bacterial Growth

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Jishnu Basu ◽  
Tiffany Grimes

Cystic Fibrosis is a genetic disease which causes the production of viscous mucus in airways which limits airflow and creates the perfect conditions for bacterial growth. Unfortunately, deaths due to bacterial infections in Cystic Fibrosis patients have increased as bacterial strains have developed antibiotic resistance.  Researchers have found that silver nanoparticles offer a solution to growing antibiotic resistance due to how no resistance has been developed to them in clinical trials. Current research is focusing on the bio-synthesis of silver nanoparticles which does not produce the harmful waste products seen with the industrial production of silver nanoparticles. However, there is a lack of comparative research concerning the effectiveness of silver nanoparticles produced by different microorganisms, which is what the researcher’s work addressed. The researcher’s work primarily focused on determining how effective silver nanoparticles produced by different bacterial species were at inhibiting bacterial growth. Through the collection of nanoparticles via extracellular synthesis, antimicrobial assays were conducted to determine the efficacy of silver nanoparticles produced by different microorganisms. The results indicated that silver nanoparticles produced by B. subtilis were the most effective in inhibiting bacterial growth. This provides a crucial as research in the field should increasingly focus on bacteria which utilize assimilatory nitrate reduction like B. subtilis because of the increased efficacy of silver nanoparticles produced by this method in inhibiting bacterial growth in aerobic conditions. Advances in this area could increase the efficiency of nanoparticle production and make it viable for industrial production.

2019 ◽  
Vol 70 (7) ◽  
pp. 2571-2573
Author(s):  
Alina Andreea Tischer (Tucuina) ◽  
Delia Berceanu Vaduva ◽  
Nicolae Balica ◽  
Alina Heghes ◽  
Adelina Cheveresan ◽  
...  

In recent years, bacterial infections in hospitals have grown particularly due to the development of antibiotic resistance. Recent research targets the discovery of new antibiotics that exhibit broad spectrum of action without adverse effects or minimizing adverse effects. In this study, the activity of biosynthesized silver nanoparticles against three bacteria commonly found in infectious diseases in the ORL sphere was evaluated. The recorded data revealed an activity comparable to that of the standard antibiotics used in these types of infections, with the observation that the activity of the nanoparticles could also be observed in the particular cases of antibiotic resistance.


2022 ◽  
Author(s):  
Jin-Liang Ma ◽  
Kexin Li ◽  
Shaobin Gu ◽  
Ying Wu ◽  
Jing Zhang ◽  
...  

Bacterial infections have posed an emerging threaten to human health. The overuse of various antibiotics is unavoidable to cause antibiotic resistance. Silver nanoparticles (AgNPs) provide an excellent candidate for combating...


2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Marc B. Habash ◽  
Mara C. Goodyear ◽  
Amber J. Park ◽  
Matthew D. Surette ◽  
Emily C. Vis ◽  
...  

ABSTRACT Increasing antibiotic resistance among pathogenic bacterial species is a serious public health problem and has prompted research examining the antibacterial effects of alternative compounds and novel treatment strategies. Compounding this problem is the ability of many pathogenic bacteria to form biofilms during chronic infections. Importantly, these communities are often recalcitrant to antibiotic treatments that show effectiveness against acute infection. The antimicrobial properties of silver have been known for decades, but recently silver and silver-containing compounds have seen renewed interest as antimicrobial agents for treating bacterial infections. The goal of this study was to assess the ability of citrate-capped silver nanoparticles (AgNPs) of various sizes, alone and in combination with the aminoglycoside antibiotic tobramycin, to inhibit established Pseudomonas aeruginosa biofilms. Our results demonstrate that smaller 10-nm and 20-nm AgNPs were more effective at synergistically potentiating the activity of tobramycin. Visualization of biofilms treated with combinations of 10-nm AgNPs and tobramycin reveals that the synergistic bactericidal effect may be caused by disrupting cellular membranes. Minimum biofilm eradication concentration (MBEC) assays using clinical P. aeruginosa isolates shows that small AgNPs are more effective than larger AgNPs at inhibiting biofilms, but that the synergy effect is likely a strain-dependent phenomenon. These data suggest that small AgNPs synergistically potentiate the activity of tobramycin against P. aeruginosa in vitro and may reveal a potential role for AgNP/antibiotic combinations in treating patients with chronic infections in a strain-specific manner.


2021 ◽  
Vol 11 (4) ◽  
pp. 197-214
Author(s):  
Mousumi Saha ◽  
Agniswar Sarkar

With the advancements of science, antibiotics have emerged as an amazing gift to the human and animal healthcare sectors for the treatment of bacterial infections and other diseases. However, the evolution of new bacterial strains, along with excessive use and reckless consumption of antibiotics have led to the unfolding of antibiotic resistances to an excessive level. Multidrug resistance is a potential threat worldwide, and is escalating at an extremely high rate. Information related to drug resistance, and its regulation and control are still very little. To interpret the onset of antibiotic resistances, investigation on molecular analysis of resistance genes, their distribution and mechanisms are urgently required. Fine-tuned research and resistance profile regarding ESKAPE pathogen is also necessary along with other multidrug resistant bacteria. In the present scenario, the interaction of bacterial infections with SARS-CoV-2 is also crucial. Tracking and in-silico analysis of various resistance mechanisms or gene/s are crucial for overcoming the problem, and thus, the maintenance of relevant databases and wise use of antibiotics should be promoted. Creating awareness of this critical situation among individuals at every level is important to strengthen the fight against this fast-growing calamity. The review aimed to provide detailed information on antibiotic resistance, its regulatory molecular mechanisms responsible for the resistance, and other relevant information. In this article, we tried to focus on the correlation between antimicrobial resistance and the COVID-19 pandemic. This study will help in developing new interventions, potential approaches, and strategies to handle the complexity of antibiotic resistance and prevent the incidences of life-threatening infections.


2020 ◽  
Author(s):  
A. Bertelsen ◽  
J.S. Elborn ◽  
B.C. Schock

AbstractCystic Fibrosis (CF), caused by mutations affecting the CFTR gene, is characterised by viscid secretions in multiple organ systems. CF airways contain thick mucus, creating a gradient of hypoxia, which promotes the establishment of polymicrobial infection. Such inflammation predisposes to further infection, a self-perpetuating cycle in mediated by NF-κB. Anaerobic Gram-negative Prevotella spp. are found in sputum from healthy volunteers and CF patients and in CF lungs correlate with reduced levels of inflammation. Prevotella histicola (P.histicola) can suppress murine lung inflammation, however, no studies have examined the role of P.histicola in modulating infection and inflammation in the CF airways. We investigated innate immune signalling and NF-kB activation in CF epithelial cells CFBE41o-in response to clinical stains of P.histicola and Pseudomonas aeruginosa (P.aeruginosa). Toll-Like Receptor (TLR) expressing HEK-293 cells and siRNA assays for TLRs and IKKa were used to confirm signalling pathways.We show that P.histicola infection activated the alternative NF-kB signalling pathway in CF bronchial epithelial cells inducing HIF-1α protein. TLR5 signalling was responsible for the induction of the alternative NF-kB pathway through phosphorylation of IKKα. The induction of transcription factor HIF-1α was inversely associated with the induction of the alternative NF-kB pathway and knockdown of IKKα partially restored canonical NF-kB activation in response to P.histicola.This study demonstrates that different bacterial species in the respiratory microbiome can contribute differently to inflammation, either by activating inflammatory cascades (P.aeruginosa) or by muting the inflammatory response by modulating similar or related pathways (P.histicola). Further work is required to assess the complex interactions of the lung microbiome in response to mixed bacterial infections and their effects in people with CF.


Author(s):  
Samuel Füchtbauer ◽  
Soraya Mousavi ◽  
Stefan Bereswill ◽  
Markus M. Heimesaat

AbstractAntibiotic resistance is endangering public health globally and gives reason for constant fear of virtually intractable bacterial infections. Given a limitation of novel antibiotic classes brought to market in perspective, it is indispensable to explore novel, antibiotics-independent ways to fight bacterial infections. In consequence, the antibacterial properties of natural compounds have gained increasing attention in pharmacological sciences. We here performed a literature survey regarding the antibacterial effects of capsaicin and its derivatives constituting natural compounds of chili peppers. The studies included revealed that the compounds under investigation exerted i.) both direct and indirect antibacterial properties in vitro depending on the applied concentrations and the bacterial strains under investigation; ii.) synergistic antibacterial effects in combination with defined antibiotics; iii.) resistance-modification via inhibition of bacterial efflux pumps; iv.) attenuation of bacterial virulence factor expression; and v.) dampening of pathogen-induced immunopathological responses. In conclusion, capsaicin and its derivatives comprise promising antimicrobial molecules which could complement or replace antibiotic treatment strategies to fight bacterial infections. However, a solid basis for subsequent clinical trials requires future investigations to explore the underlying molecular mechanisms and in particular pharmaceutical evaluations in animal infection models.


2020 ◽  
Vol 17 (168) ◽  
pp. 20200105
Author(s):  
Eliott Jacopin ◽  
Sonja Lehtinen ◽  
Florence Débarre ◽  
François Blanquart

The evolution of multidrug antibiotic resistance in commensal bacteria is an important public health concern. Commensal bacteria such as Escherichia coli , Streptococcus pneumoniae or Staphylococcus aureus , are also opportunistic pathogens causing a large fraction of the community-acquired and hospital-acquired bacterial infections. Multidrug resistance (MDR) makes these infections harder to treat with antibiotics and may thus cause substantial additional morbidity and mortality. Here, we develop an evolutionary epidemiology model to identify the factors favouring the evolution of MDR in commensal bacteria. The model describes the evolution of antibiotic resistance in a commensal bacterial species evolving in a host population subjected to multiple antibiotic treatments. We combine statistical analysis of a large number of simulations and mathematical analysis to understand the model behaviour. We find that MDR evolves more readily when it is less costly than expected from the combinations of single resistances (positive epistasis). MDR frequently evolves when bacteria are in contact with multiple drugs prescribed in the host population, even if individual hosts are only treated with a single drug at a time. MDR is favoured when the host population is structured in different classes that vary in their rates of antibiotic treatment. However, under most circumstances, recombination between loci involved in resistance does not meaningfully affect the equilibrium frequency of MDR. Together, these results suggest that MDR is a frequent evolutionary outcome in commensal bacteria that encounter the variety of antibiotics prescribed in the host population. A better characterization of the variability in antibiotic use across the host population (e.g. across age classes or geographical location) would help predict which MDR genotypes will most readily evolve.


Author(s):  
Bhavani J ◽  
Sunil Kumar Prajapati ◽  
Ravichandran S

Opportunistic bacterial infections are common in the various parts of human body. In recent years bacterial species have shown resistance against a number of synthetic drugs. This study measured the antibacterial activity of bacterial strains against five common pathogenic bacteria related strains. Cup plate method and two fold serial dilution method were used to evaluated by antibacterial activity by the help of different bacterial related strains. The results revealed that Cisplatin (CIP) using natural as a polymer showed a minimum inhibitory concentration (MIC) at 250 mg/ml to 500 mg/ml of the broth against all bacterial strains. CIP using natural as a polymer was prepared different doses1000 μg/ml and 2000 μg/ ml and measured zone of inhibition dose dementedly reduced when compared to standard. The CIP using natural as a polymer exhibited strong anti-bacterial activity against five different species of bacteria and this may be attributed to various active components. Our research work has been indicated Nanoparticles containing CIP using natural as a polymer formulated for the enhanced anti-cancer activity through antimicrobial mechanism. 


Author(s):  
G.M. Rossolini

Antibiotics are one of the most significant advancements of modern medicine. They have changed the prognosis of several bacterial infections, and made possible advanced medical practices associated with a high risk of infectious complications. Unfortunately, antibiotics are affected by the phenomenon of antibiotic resistance, which jeopardizes their efficacy. In recent years, antibiotic discovery and development has been lagging, due to a lower appeal of this sector for the pharmaceutical industry, while antibiotic resistance has continued to evolve with the eventual emergence and dissemination of bacterial strains which are resistant to most available antibiotics and pose a major challenge to antimicrobial chemotherapy. This worrisome scenario, indicated as the “antibiotic resistance crisis”, has been acknowledged by Scientific Societies and Public Health Agencies, and is now gathering an increasing attention from the Media and Governments. This article reviews the antibiotic-resistant pathogens which currently pose major problems in terms of clinical and epidemiological impact, and briefly discuss future perspective in this field.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1479
Author(s):  
Kristen M. Tummillo ◽  
Karsten R.O. Hazlett

Bioconjugation has allowed scientists to combine multiple functional elements into one biological or biochemical unit. This assembly can result in the production of constructs that are targeted to a specific site or cell type in order to enhance the response to, or activity of, the conjugated moiety. In the case of cancer treatments, selectively targeting chemotherapies to the cells of interest limit harmful side effects and enhance efficacy. Targeting through conjugation is also advantageous in delivering treatments to difficult-to-reach tissues, such as the brain or infections deep in the lung. Bacterial infections can be more selectively treated by conjugating antibiotics to microbe-specific entities; helping to avoid antibiotic resistance across commensal bacterial species. In the case of vaccine development, conjugation is used to enhance efficacy without compromising safety. In this work, we will review the previously mentioned areas in which bioconjugation has created new possibilities and advanced treatments.


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