Current Developments in the Detection and Control of Multi Drug Resistance

Antimicrobial resistance occurs naturally over time due to changes at the genetic level of microorganisms. These microorganisms are present in food, animals, plants, humans, and the environment. Many pathogens can spread from people to people or from animals to humans. Some of the major drivers of the development of antimicrobial resistance are misuse (overuse, inappropriate selection and/or dosing, etc.) of antimicrobial agents, poor infection and disease management, lack of access to clean water, sanitation and hygiene for the people, poor access to affordable and quality drugs and diagnostics, lack of awareness and knowledge about health care, etc.

The phenomenon of drug resistance is a widely acknowledged problem in clinics. Drug resistance not only increases the treatment time, but also paves the way for testing the maximum limit of dose tolerance of antibiotics in the patient. There is no escaping of the fact that drug tolerance may remain a perpetual problem and bacteria will keep on evolving as a part of the natural selection process. Therefore, novel drugs targeting the novel mechanism of action could be a proposed solution for this problem. The mechanism of action includes efflux pump, alteration/modification of drug target, enzyme inactivation and prevention of drug penetration. The other thing is to avoid the unnecessary usage of antibiotics so that the bacteria living inside the body do not develop resistance. The places where antibiotics can be bought for human or animal use without a prescription, the emergence and spread of resistance are made worse. Similarly, in countries without standard treatment guidelines, antibiotics are often overprescribed by health workers and veterinarians and over-used by the public. Therefore, this unregulated overuse of antibiotics may lead to an era where normal infection may become difficult to treat and could lead to mortality. The maintenance of hygiene is a must for everyone and it is the only way to get rid of pathogenic bacteria. So, in this chapter, we summarize recent literature on the development of drug resistance, their mechanism of actions used by microbes to develop antibiotic resistance, factors determining their development by infective agents and the spread of resistant bacteria. 

Multiple-Drug Resistance (MDR) is a mechanism that renders the ineffectiveness of one or more than one antimicrobial agents shown by disease causing microorganisms. MDR has become one of the major public health challenges as initially, the MDR species were restricted only to hospitals, but now they are found everywhere. Due to the slow advancements in the discovery of new or different antibiotics against the MDR organisms, the medical society is facing great challenges in the treatment of infections caused by resistant microorganisms. This chapter outlines the challenges involved in drug discovery, and treatment to fight and prevent MDR infections. 

World health organization (WHO) has acknowledged the problem of multidrug resistance (MDR) bacteria as an endemic and widespread problem globally. MDR in LMICs represents one of the biggest threats to global health and is one of the greatest current challenges in infectious disease research. High mortality/morbidity rates of MDR infections are mainly due to the lack of timely, rapid detection and treatment of the causative pathogen. Molecular mechanism conferring MDR against most common treatment options includes mutations in antibiotics’ susceptible genes at one or many sites. A number of methods, including culture-based, nucleic acid-based amplification of resistance conferring genes, and immunological based assays have been developed to detect MDR. Each method has defined specificity, sensitivity and time around to detect MDR infections in clinical settings. 

 Diseases caused by pathogenic microbes have been a serious problem since decades. They often cause high mortality in both developing and developed countries. Diseases including diarrhea, cholera, typhoid, etc., are often involved in outbreaks related to pathogens surviving in water. In recent years, the management of infectious diseases has drawn much attention among scientists and researchers. Various specific, sensitive and reproducible detection methods have been developed to identify pathogen contamination in water. These advanced methods generally use probes for diagnostics of pathogens. The present chapter attempts to focus on the development of various probe chemistries for the detection of pathogens. We also intend to present here the pros and cons of different methods. 

High Resolution Melting (HRM) is a homogeneous, exceptionally incredible innovation for single nucleotide polymorphism (SNP) genotyping, mutation scanning and sequence scanning in DNA samples. HRM analysis works on the principle of melting (dissociation) curve methodologies of Polymerase Chain Reaction (PCR) empowered by the new accessibility of improved double-stranded DNA (dsDNA)–binding dyes and next-generation real-time PCR instrumentation. The HRM technology portrays samples of nucleic acids on the basis of their disassociation behaviors and identifies the differences in even the short sequence in amplified PCR products, just by direct melting. Samples are further distinguished according to the length of their sequence, GC content and strand complementarity. Indeed, even a single change in the base pair in the sequences of DNA samples causes differences in the HRM curve. The difference in the melting curves of different genetic sequences at distinct rates can be observed, detected and compared using these curves. Development of the melting curves after HRM analysis is basically plotted with temperature on the X axis and fluorescence on the Y axis, which resembles the real-time PCR amplification curve but with the difference of temperature for cycle number. With the use of different DNA dyes, high-end instrumentation and sophisticated analysis software, these distinctions are detected.

Multiple-Drug Resistance (MDR) against many antibiotics and other therapeutic agents is a major concern for health care providers and researchers in the field. Due to tremendous rise in MDR cases, researchers are in search of potent therapeutic options or alternatives to overcome MDR. Here, in this chapter, we will discuss the current status of the common as well as advanced methods which have been developed so far for the treatment of MDR and also the challenges and opportunities in each of those methods. This chapter discusses common methods used for the treatment of MDR, i.e., major antibiotics used for the treatment of MDR bacteria and synergistic approaches by the combination of different antibiotics. Along with common treatments used against MDR bacteria, this chapter also discusses current treatments like antimicrobial peptides, anti-virulence compounds, phage therapy and drug repurposing approaches for MDR treatment.

 Microbial pathogens have always been a great threat to many life forms, including human. To control microbial infection, especially bacterial infection antibiotics have been a boon. However, with the changing scenario, the bacteria have also evolved and developed resistance against many antibiotics and these pathogens have become more fatal. On the other hand, plants and plant products have been used as a natural resource to control these microbes. The plant seed oil has also been explored for the same; however, comparatively less literature is available on antimicrobial activities of seed oil derived from plants. Looking at the importance of seed oil in this field, the present review article presents a brief discussion about various aspects of seed oil and their application against bacteria.

 Penicillin discovery has put forward great expectations and hope for the treatment of several infectious diseases. Inappropriate and excess use of antibiotics has led to the emergence of antibiotic-resistant (AMR) worldwide, which has become one of the greatest threats to global health. However, in the late 1940s, after approval, mass production (lead to reduced cost) and supply (lead to easy access to all people) led to the emergence of Antimicrobial Resistance (AMR). A similar behavioral pattern ensued as other classes of antibiotics were discovered (through increasing utilization to resistance). Substandard infection control practices in public healthcare settings eased the spread and transmission of resistant organisms and intensified antimicrobials' effect. The healthcare community responded with two major programs – Infection Control in the 1980s and Antimicrobial Stewardship (in the last decade). These programs depend on the end-user; however, while the importance of such global control and prevention programs cannot be disputed, these efforts alone are insufficient against the advent of AMR. Also, drug discovery has suffered from a shortage of exploitable bacterial target sites, leading to the slow evolution of novel potent drugs. 

Infections caused by MDR (Multi-drug resistant) strains are increasing with time due to the selection pressure posed by the use of antibiotics. The mechanisms that confer antibiotic resistance to bacteria are gene mutation, change in cell envelop, over expression of efflux pumps and biofilm formation. Drug development for MDR has become one of the major challenges globally. MDR infections associated with health care facilities are difficult to treat due to the limited therapeutic approaches or even no treatment options. Therefore, there is an emergency to develop new therapeutic approaches against MDR pathogens. It is possible to identify proteins that are responsible for the survival of pathogenic MDR bacteria for the purpose of drug discovery. Rational-structure based drug design is an inventive process of finding new drug targets, which relies on the knowledge of three-dimensional structure of biological targets. The three-dimension structure is obtained by high throughput techniques such as X-ray diffraction (XRD), Nuclear Magnetic Resonance (NMR) and Cryo-electron microscopy (Cryo- EM). Structure biology plays an important role in the characterization of new therapeutic targets and assessment of drug targets. Computational methods boost drug development and discovery process against MDR pathogens and analyse efficient therapies.

This chapter focuses on the solutions to emerging multidrug resistance in the major parasitic protozoa plaguing the world. These neglected pathogens have seized the developing nations in a vice-like grip and are seeping into the industrialised world with the dramatic increase in global travel. The alarming rise in resistance to most antiparasitic drugs has left even the wealthiest nations vulnerable. Multidrug resistance occurs to give a survival advantage to the parasite; it has been hastened by the uncontrolled use of chemotherapeutics. This chapter categorises the recent developments to overcome the MDR hurdle under different approaches. The synthesis of novel organic compounds and high-throughput screenings of new chemical entities are two major approaches. Protease and topoisomerase inhibitors of parasitic protozoa prove as worthy drug targets. In-silico and proteomics-based methods also accelerate drug discovery by creating potential drug libraries specific to tropical protozoa. A costeffective and rapid method of combating drug resistance is the repurposing of licensed medicines. This approach also accounts for the established safety of drugs and high commercial availability. Molecular advancements have introduced small interfering RNAs (siRNAs) at preclinical levels as therapeutics functioning via a unique mechanism. The nanoparticle and cell-penetrating peptides (CPP) based delivery of siRNAs has facilitated a stable and low toxic way to silence genes providing pathogenicity and resistance. This will help in reversing MDR and breathing new life into the existing licensed antiprotozoal chemotherapies.