Antibiotics and Antimicrobial Resistance Genes in the Environment

Volume 1 in the Advances in Environmental Pollution Research series

Muhammad Zaffar Hashmi

• Publisher: Elsevier
• Year: 2019
• Print ISBN: 9780128188828
• eBook ISBN: 9780128188835
• Topic: Ciencias biológicas
• Subtopic: Ciencia medioambiental

Antibiotics and Antimicrobial Resistance Genes (AMR) in the Environment summarizes and updates information on antibiotic producing organisms and their resistance and entry routes in soil, air, water and sediment. As antibiotic use continues to rise in healthcare, their fate, bioavailability and biomonitoring, and impacts on environment and public health are becoming increasingly important. The book addresses the impact of antibiotics and AMR to environment and public health and risk assessment. Moreover, it focused on the metagenomics and molecular techniques for the detection of antibiotics and antimicrobial genes. Lastly, it introduces management strategies, such as treatment technologies for managing antibiotics and AMR/ARGs-impacted environment, and bioremediation approaches.- Summarizes and updates information on antibiotics and AMR/ARGs production and its fate and transport in the environment- Includes phytoremediation and bioremediation technologies for environmental management- Provides analysis of risk assessment of antibiotic resistance genes to help understand the environmental and socioeconomic impacts of antibiotics and AMR/ARGs

Chapter 1

Microorganisms and antibiotic production

Kanwal Rehman ¹ , Sania Niaz ^{1 , 2} , Ayesha Tahir ^{1 , 2} , and Muhammad Sajid Hamid Akash ^{3 1} Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan ² Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad, Pakistan ³ Department of Pharmaceutical Chemistry, Government College University Faisalabad, Faisalabad, Pakistan

Abstract

Microorganisms are the main culprit for the development of infections that can be prevented by the use of antimicrobial agents. Therapeutic efficacy of antimicrobial agents is based on the selectivity of toxicity having capability to kill the invading microorganisms without harming the host cells, but their production and stability are major concerns. Till now, several techniques have been developed to produce antimicrobial agents, and different strategies have also been adopted to prolong the stability of antimicrobial agents. In this chapter, we have briefly described the most commonly used methods for the production of antimicrobial agents. Moreover, we have also discussed in detail how antimicrobial resistance is developed as well as various methods, notably microencapsulation, that are used for the stability of antimicrobial agents.

Keywords

Antibiotic resistance; Antimicrobial agents; Microencapsulation; Prebiotics; Probiotics

1.1. Introduction

Microorganisms are organisms or infectious agents of microscopic or submicroscopic size, which include bacteria, fungi, protozoans, and viruses. For the treatment of infections, antimicrobial drugs are valuable due to selectivity of their toxicity, thereby having capability to kill the invading microorganisms without harming the host cells. Antimicrobial medicines can be classified according to their action against the microorganisms. For example, antibiotics are used against bacteria, whereas antifungals are specifically used against fungi. The term probiotic was introduced by Lilly and Stillwell (Lilly and Stillwell, 1965).

1.2. Probiotics

The use of probiotics for their health benefits is increasing worldwide (Agheyisi, 2005). The word probiotic is derived from the Greek word meaning for life and has had several different meanings over the years. Improving the host health by consumption of live microorganisms provides a basic concept of a probiotic. A probiotic can be defined as microorganism introduced into the body in sufficient quantity for its beneficial qualities into the host. Gut health or microflora can be improved by the utilization of typical microorganisms that are present in fermented products (Hill et al., 2014; Ndowa et al., 2012). According to the mechanistic approach, disorder or imbalance of important intestinal microflora leads to many gastrointestinal infirmity or infections. Probiotics are viable microbial cultures that maintain or balance the microflora of intestine, correct the microbial dysfunction, and enhance the host health and well-being (Fuller, 1989; Rokka and Rantamäki, 2010). Two of the most common microbes that are widely used as probiotics are Lactobacillus and Bifidobacteria strains. Growth of the concerned microorganism is stimulated by using the bacterial culture of probiotics, which improves the natural defensive mechanism of the body and also disrupts the harmful bacteria (Dunne, 2001).

Probiotics have shown a curative role against cancer, and they also have been shown to reduce cholesterol levels, modify lactose intolerance, and enhance immunity (Kailasapathy and Chin, 2000). As probiotics boost immunity, they provide beneficial health effects by the stimulation of cell- mediated immune responses as well as enhance the antibody secretions. Probiotics are selected according to the protection point of view against microbial pathogens (Cross, 2002) and also play a vital role in maintaining the overweight of an obese adult (Kadooka et al., 2010).

1.3. Prebiotics

Prebiotic concepts were introduced in 1995 by Gibson and Roberfroid as a substitute approach to alter or modify the microbiota of the gut (Gibson and Roberfroid, 1995). A prebiotic is a nondigestible food ingredient, usually bifidobacteria and lactobacilli, that beneficially affects the host by enhancing the growth and/or activity of one or a limited number of specific species of bacteria in the gut, thus strengthening the host health. They are indigestible by human enzymes because they have short-chain carbohydrates (SCCs), so-called resistant SCCs (Quigley et al., 1999). To be considered as a prebiotic, a food ingredient must have specific properties. For example, (1) it should be resistant by passing the upper portion of gastrointestinal track for the absorption and hydrolysis; (2) it should provide a favorable environment by modifying the microflora of the colon and provide more healthy and favorable composition there; and (3) it should show specific property of selective substrate for one or a specific amount of colon bacteria (Park and Kroll, 1993). Hence there are numerous potential applications of prebiotics.

Prebiotics should be resistant to being hydrolyzed by intestinal enzymes of the human but should be fermented by specific bacteria and should have fruitful effects for the host. Upon administration, prebiotics should have beneficial outcomes including lowering the permeability of intestine, decreasing triglyceride levels, and improving glucose levels after eating (Cani et al., 2009; Gibson and Roberfroid, 1995). Prebiotics are widely used as a supplement and can be formulated in various ways such as syrups or powder and also into different food products, particularly in bread and yogurt, that provide beneficial health effects by enhancing the minerals’ bioavailability (Roberfroid et al., 2010). They have also been recommended for improved bone and mineral metabolism.

1.4. Symbiotics

It has been suggested that symbiotics are the combination of probiotics and prebiotics, not only comprising the combined effects of these two probiotics and prebiotics but also purposed to have a synergistic effect (Rafter et al., 2007).

1.5. Antibiotics

Many of the antibiotics are the essential excretions of environmental bacteria and fungi. At present, these antibiotics are used as a major source of human medicines for the treatment of infections (Kieser et al., 2000).

1.5.1. Classification of antibiotics

The most important classification of antibiotics is based on their spectrum, mode of action, and molecular structure. There are certain ways to classify antibiotics (Calderón and Sabundayo, 2007), notably, one method is based on their route of administration such as topically, orally, or as an injectable. Other antibiotics that are related to the same structural class will show analogous patterning of efficiency, allergic side effects, and toxicity. Some common classes of antibiotics like macrolides, quinolones, tetracyclines, aminoglycosides, sulfonamides, oxazolidinones, glycopeptides, and beta-lactam are based on their molecular and chemical structures (Adzitey, 2015; Frank and Tacconelli, 2012; Van Hoek et al., 2011). For many years, antibiotics have proven efficacious in providing a curative response for many contagious diseases. Antibiotics include composites that hinder the growth of microorganisms, which are considered as “antimicrobial agents.” Several natural antibiotics can also be used in the treatment of numerous diseases.

1.5.2. Mechanisms of antibiotic resistance

Antibi...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Acknowledgment
• Chapter 1. Microorganisms and antibiotic production
• Chapter 2. Antibiotics and antimicrobial resistance: temporal and global trends in the environment
• Chapter 3. Antibiotics’ presence in hospitals and associated wastes
• Chapter 4. Current trends of antimicrobials used in food animals and aquaculture
• Chapter 5. Major natural sinks for harboring microorganisms with altered antibiotic resistance versus major human contributing sources of antibiotic resistance: a detailed insight
• Chapter 6. Dissemination of antibiotic resistance in the environment
• Chapter 7. Long-range transport of antibiotics and AMR/ARGs
• Chapter 8. Antibiotics and antimicrobial resistance mechanism of entry in the environment
• Chapter 9. Antibiotics, AMRs, and ARGs: fate in the environment
• Chapter 10. On the edge of a precipice: the global emergence and dissemination of plasmid-borne mcr genes that confer resistance to colistin, a last-resort antibiotic
• Chapter 11. Uptake mechanism of antibiotics in plants
• Chapter 12. Modeling the spread of antibiotics and AMR/ARGs in soil
• Chapter 13. Metagenomics and methods development for the determination of antibiotics and AMR/ARGS
• Chapter 14. Global trends in ARGs measured by HT-qPCR platforms
• Chapter 15. Databases, multiplexed PCR, and next-generation sequencing technologies for tracking AMR genes in the environment
• Chapter 16. Toxicity of antibiotics
• Chapter 17. Carbapenems and Pseudomonas aeruginosa: mechanisms and epidemiology
• Chapter 18. Environmental and public health effects of antibiotics and AMR/ARGs
• Chapter 19. Antibiotics resistance mechanism
• Chapter 20. Microbial risk assessment and antimicrobial resistance
• Chapter 21. Environmental risk assessment of antibiotics and AMR/ARGs
• Chapter 22. Nanobiotechnology-based drug delivery strategy as a potential weapon against multiple drug-resistant pathogens
• Chapter 23. Treatment technologies and management options of antibiotics and AMR/ARGs
• Index