Novel silver nanoparticle-antibiotic combinations as promising antibacterial and anti-biofilm candidates against multiple-antibiotic resistant ESKAPE microorganisms.

HYPOTHESIS: The emergence of Multiple Antibiotic Resistance (MAR) in ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens is a global challenge to public health. The inherent antimicrobial nature of silver nanoparticles (AgNPs) makes them promising antimicrobial candidates against antibiotic-resistant pathogens. This study explores the combination of AgNPs with antibiotics (SACs) to create new antimicrobial agents effective against MAR ESKAPE microorganisms. METHODS: AgNPs were synthesized using Streptococcus pneumoniae ATCC 49619 and characterized for structure and surface properties. The SACs were tested against ESKAPE microorganisms using growth kinetics and time-kill curve methods. The effect of SACs on bacterial biofilms and the disruption of cell membranes was determined. The in-vitro cytotoxicity effect of the AgNPs was also studied. FINDINGS: The synthesized AgNPs (spherical, 7.37±4.55 nm diameter) were antimicrobial against MAR ESKAPE microorganisms. The SACs showed synergy with multiple conventional antibiotics, reducing their antibacterial concentrations up to 32-fold. Growth kinetics and time-kill studies confirmed the growth retardation effect and bactericidal activity of SACs. Mechanistic studies suggested that these biofilm-eradicating SACs probably resulted in the loss of bacterial cell membrane integrity, leading to leakage of the cytoplasmic content. The AgNPs were highly cytotoxic against skin melanoma cells but non-cytotoxic to normal Vero cells.

FEAMR: A Database for Surveillance of Food and Environment-Associated Antimicrobial Resistance.

The rapid dissemination of antimicrobial resistance (AMR) has emerged as a serious health problem on an unprecedented global scale. AMR is predicted to kill more than 10 million people annually by 2050 leading to huge economic losses worldwide. Therefore, urgent action is required at the national as well as international levels to avert this looming crisis. Effective surveillance can play an important role in the containment of AMR spread by providing data to help determine AMR hotspots, predict an outbreak, maintain proper stewardship and propose immediate and future plans of action in this respect. Although many existing databases provide genetic and molecular information on AMR in microorganisms, there is no dedicated database of AMR from non-clinical samples. The FEAMR database is a one-of-its-kind database to provide manually collated and curated information on the prevalence of AMR in food and the environment. For designing the FEAMR webpage, Microsoft Visual Studio with HTML, CSS, ASP.NET, Bootstrap for the front-end and C# for the back-end were used. The FEAMR database is a free access resource ( https://feamrudbt-amrlab.mu.ac.in/ ), accepting verified food- and environment-related AMR submissions from across the globe. To the best of our knowledge, it is probably the first database providing AMR-related surveillance data from non-clinical samples. It is designed from the 'One Health Approach' perspective to help in the containment of global AMR spread. Flowsheet of steps for making FEAMR database 1. Research articles relating to Antimicrobial Resistance (AMR) were searched on the internet. 2. Data relating to AMR were retrieved from these articles and stored in an MS-Excel sheet. 3. The web pages of the FEAMR database (DB) were created using Microsoft Visual Studio (MVS) and its various tools. HTML, CSS, ASP.NET and Bootstrap were used for the front end and C# used for the back-end of the website. 4. The DB of FEAMR was created using MS SQL Server which was controlled by SQL Server Management Studio (SSMS). 5. The data from the MS-Excel sheet in step 2 was stored in the SQL server and displayed on the web page using GridView tool of MVS and C#. The database created was then uploaded on the University of Mumbai (UoM) website, where it can be accessed by all users having the link to the DB ( https://feamrudbt-amrlab.mu.ac.in/ ).