Alternative Therapies to Antibiotics to Combat Drug-Resistant Bacterial Pathogens

Abstract

The unabated emergence and spread of antimicrobial resistance (AMR) within both nosocomial and community environments is the driving force behind the urgent need to discover novel antimicrobial agents. However, owing to the challenges faced during conventional drug discovery programmes and the concomitant paucity of new drugs, it is prudent to focus on non-conventional approaches that could serve as alternatives to antibiotics. These approaches include all non-compound approaches that target pathogens other than antibiotics. Although these alternatives may or may not be absolute replacements of antibiotics, they can certainly be used in prophylaxis and in combination therapies with antibiotics to reduce the overuse and help prevent AMR. The advantage of this approach includes specific inhibition of pathogens without effecting the host’s commensal beneficial microbiome. This is in direct contrast to antibiotic therapies which disturb the commensal bacteria, leading to increased risks of Clostridium difficile-associated diarrhoea, vaginal Candida albicans infections and the exacerbation of asthma and allergic diseases. Although a consistent efficacy is lacking, switching to alternatives will certainly reduce antibiotic abuse to a large extent and consequent resistance. Further development of these specific approaches is warranted to improve deliverability, potency and reliability. Thus, the investigation of novel non-antibiotic approaches for the prevention of, and protection against, infectious diseases should be stimulated, and such approaches must be high-priority research and development projects. The alternative approaches to antibiotics include immunomodulation, competitive exclusion of pathogenic bacteria via probiotics and their combination, natural and synthetic antimicrobial peptides, antibodies, bacteriophages and phage lysins. These alternative strategies are considered in this chapter.