Advances in solid-phase extraction techniques: role of nanosorbents for the enrichment of antibiotics for analytical quantification.

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Authors: Medapati Nikitha Lakshmi Suseela, Matte Kasi Viswanadh, Abhishesh Kumar Mehata, Vishnu Priya, Vikas Aseem Setia, Ankit Kumar Malik, Patharaj Gokul, Joseph Selvin,Madaswamy S. Muthu

Abstract:

Antibiotics are life-saving medications for treating bacterial infections; however it has been discovered that resistance developed by bacteria against these incredible agents is the primary contributing factor in rising global mortality rates. The fundamental cause of the emergence of antibiotic resistance in bacteria is the presence of antibiotic residues in various environmental matrices. Although antibiotics are present in diluted form in environmental matrices like water, consistent exposure of bacteria to these minute levels is enough to for the resistance to develop. So, identifying these tiny concentrations of numerous antibiotics in various and complicated matrices will be a crucial step in controlling their disposal in those matrices.

Solid phase extraction, a popular and customizable extraction technology, was developed according to the aspirations of the researchers. It is a unique alternative technique that could be implemented either alone or in combination with other approaches at different stages because of the multitude of sorbent varieties and techniques. Initially, sorbents are utilized for extraction in their natural state. The basic sorbent has been modified over time with nanoparticles and multilayer sorbents, which have indeed helped to accomplish the desired extraction efficiencies. Among the current traditional extraction techniques such as liquid-liquid extraction, protein precipitation, and salting out techniques, solid-phase extractions (SPE) with nanosorbents are most productive because, they can be automated, selective, and can be integrated with other extraction methods specifically. This review aims to provide a broad overview of advancements and developments in sorbents with a specific emphasis on the applications of SPE techniques used for antibiotic detection and quantification in various matrices in the last two decades.

The menace of colistin resistance across globe: Obstacles and opportunities in curbing its spread.

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Authors: P.S. Seethalakshmi, Riya Rajeev, Anushara Prabhakaran, George Seghal Kiran, Joseph Selvin

Abstract: 

Colistin-resistance in bacteria is a big concern for public health, since it is a last resort antibiotic to treat infectious diseases of multidrug resistant and carbapenem resistant Gram-negative pathogens in clinical settings. The emergence of colistin resistance in aquaculture and poultry settings has escalated the risks associated with colistin resistance in environment as well. The staggering number of reports pertaining to the rise of colistin resistance in bacteria from clinical and non-clinical settings is disconcerting. The co-existence of colistin resistant genes with other antibiotic resistant genes introduces new challenges in combatting antimicrobial resistance. Some countries have banned the manufacture, sale and distribution of colistin and its formulations for food producing animals. However, to tackle the issue of antimicrobial resistance, a one health approach initiative, inclusive of human, animal, and environmental health needs to be developed.

Herein, we review the recent reports in colistin resistance in bacteria of clinical and non-clinical settings, deliberating on the new findings obtained regarding the development of colistin resistance. This review also discusses the initiatives implemented globally in mitigating colistin resistance, their strength and weakness.

Fast and highly efficient liquid chromatographic methods for qualification and quantification of antibiotic residues from environmental waste

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Authors: Abhishesh Kumar Mehata, M. Nikitha Lakshmi Suseela, Patharaj Gokul, Ankit Kumar Malik, Matte Kasi Viswanadh, Chandrashekhar Singh, Joseph Selvin, Madaswamy S. Muthu

Abstract: 

Antibiotics are life-saving drugs, projecting their pivotal role in preventing and mitigating infectious diseases from the time of their evolution. The mass production of antibiotics was started in the twentieth century, primarily of semisynthetic derivatives of naturally occurring antimicrobial molecules and a few purely synthetic compounds. As a result, the whole bacterial populations were subjected to unprecedented antibiotic evolutionary pressures, leading to the accelerated development of antimicrobial resistance (AMR) among many infectious microorganisms that we encounter today. Consistent disposal and perseverance of antibiotics in ecosystems have been recognized as evolving environmental health hazards. Conventional techniques for removing antibiotics, such as wastewater treatment plants, have been proved to be inefficient. In addition, antibiotics should be proactively removed from environmental matrices. For setting the standard guideline by authorities for antibiotics disposal in the environment and their confinements, it is essential to develop highly efficient analytical methods for the qualification and quantification of antibiotic residues in the environmental matrices. Generally, antibiotics in the environmental matrices are complex and below the nanogram or picogram range; hence, sample purification and enrichment are quite essential prior to analysis.

This review presents an overview of sampling techniques for antibiotics from environmental matrices, their purification and enrichment by liquid–liquid extraction, solid phase extraction, lyophilization and rotary evaporation. The review highlighted various qualification and quantification of extracted antibiotics that have been carried out by using high performance liquid chromatography (HPLC), ultra-high performance liquid chromatography (UPLC) and liquid chromatography tandem mass spectroscopy (LC-MS/MS).

Delineating the impact of COVID-19 on antimicrobial resistance: An Indian perspective.

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Authors: Seethalakshmi PS, Charity OJ, Giakoumis T, Kiran GS, Sriskandan S, Voulvoulis N, Joseph Selvin

Abstract: 

The COVID-19 pandemic has shattered millions of lives globally and continues to be a challenge to public health due to the emergence of variants of concern. Fear of secondary infections following COVID-19 has led to an escalation in antimicrobial use during the pandemic, while some antimicrobials have been repurposed as treatments for SARS-CoV-2, further driving antimicrobial resistance. India is one of the largest producers and consumers of antimicrobials globally, hence the task of curbing antimicrobial resistance is a huge challenge. Practices like empirical antimicrobial prescription and repurposing of drugs in clinical settings, self-medication and excessive use of antimicrobial hygiene products may have negatively impacted the prevalence of antimicrobial resistance in India. However, the expanded production of antimicrobials and disinfectants during the pandemic in response to increased demand may have had an even greater impact on the threat of antimicrobial resistance through major impacts on the environment.

The review provides an outline of the impact COVID-19 can have on antimicrobial resistance in clinical settings and the possible outcomes on the environment. This review calls for the upgrading of existing antimicrobial policies and emphasizes the need for research studies to understand the impact of the pandemic on antimicrobial resistance in India.