• The propensity for the development of bacterial resistance to conventional antibiotics poses serious public health problems
‘Resistance’ describes the inherited ability of microorganisms to grow at high concentrations of an antibiotic, irrespective of the duration of treatment, and is quantified by the minimum inhibitory concentration (MIC).
Molecular mechanisms of resistance include mutations in the drug target, enzymatic activity that directly inactivates the antibiotic and the activation of efflux pumps.
Bacteria are also able to survive extensive antibiotic treatments without acquiring resistance mutations: ‘tolerance’ and ‘persistence’.
• The mechanism of action of antibiotics varies as they damage pathogens in several ways.
Fig. Mechanisms of antibiotics actions (Microbiology 12th Std)
• In addition to viruses and bacteria, fungi are the other organisms, that are either equally or more dangerous to human health.
• Biofilm is a three-dimensional community of bacteria with intricate architecture that lives on surfaces and is encapsulated in a network of hydrated polysaccharides, proteins and DNA
• Phages are simple, non-living biological entities.
• Phages bind to specific receptors on the bacterial cell surface, inject their genetic material into the host cell, and then either integrate this material into the bacterial genome, or hijack the bacterial replication machinery to produce the next generation of phage progeny and lyse the cell.