Development in antimicrobial agents

Antibiotic-resistant bacteria cause life-threatening infections in hospitals and society in general. There is a vital requirement to develop new antimicrobial agents, but this task involves extensive scientific trials. This chapter reviewed broad-spectrum polymeric antimicrobials, which are not susceptible to current resistance, and mechanisms of bacteria to mimic the antimicrobial action of natural HDP, which exert their effect by permeabilising the bacterial cytoplasmic membrane. Most cationic antimicrobial polymers appear to work in a manner similar to membrane-active AMP, such as magainin. The design and synthesis of different polymers, such as methacrylate-based copolymers, PPE, polynorbornene by-products, amphiphilc arylamide polymers and large polymers, have been studied as biomimetic polymers in different applications. 

Bacteria can develop resistance to antimicrobial agents as a result of mutational changes in the chromosome or via the acquisition of genetic material (resistance genes carried on plasmids or transposons or the recombination of foreign DNA into the chromosome) (Fig. 2). 

Host factors can help to ensure selection of the most appropriate antimicrobial agent. Age is an important factor in antimicrobial selection. With regard to dose and interval, renal and hepatic function varies with age. Populations with diminished renal function include neonates and the elderly. Hepatic function in the neonate is not fully developed, and drugs that are metabolized or eliminated by this route may produce adverse effects. For example, sulfonamides and ceftriaxone may compete with bilirubin for binding sites and may result in hyperbilirubinemia and kernicterus. Gastric acidity also depends on... 

As proposed in earlier publications, an ideal antimicrobial agent for the treatment of bacterial causes of infectious diarrhea would have the following features [1, 2] (1) excellent activity against a broad range of bacterial enteropathogens (2) nonabsorbable (3) favorable side effect profile (4) efficacious in the treatment of infectious diarrhea (5) major indication is enteric disease, and (6) does not easily develop resistance or promote cross-resistance. 

Bacterial resistance to conventional antibiotics has become a serious problem in infection control, and has led to intensive research efforts to develop an effective novel antimicrobial agent. Antimicrobial peptides have already played a crucial role in pharmaceutical research as biomedically useful agents or as lead compounds for drug development. More specifically, cyclic peptides have shown some potential as a possible new class of... 

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