Pathogens and other microorganisms

Plant residues can provide substrates for the production of phytotoxic metabolites by soil microorganisms but they can also support the growth of pathogens and other deleterious micro-organisms. This is illustrated by reference to the problems of establishing crops drilled in the presence of straw residues and of decaying weed and grass residues that have been previously killed with herbicides. 

Disinfection is the destruction of pathogenic and other kinds of microorganisms such as viruses, bacteria, and fungi by physical or chemical means. 

Bacteria are essentially unicellular, although some species arise as sheathed chains of cells. They possess the properties listed under prokaryotes in Table 2.1, but, like viruses and other categories of microorganisms, exhibit great diversity of form, habitat, metabolism, pathogenicity and other characteristics. The bacteria of interest in pharmacy and medicine belong to the group known as the... 

Clearly two distinct issues arise from these observations. The first is whether the development of nonsusceptibility to antiseptics by nosocomial pathogens, skin flora, and other microorganisms results in decreased clinical efficacy of the topical antiseptics used in healthcare settings. The second issue is whether the emergence of resistance to the antiseptics will result in cross-resistance to clinically useful antibiotics. The concern in the latter case is that the wide availability and use of antiseptics and the selection pressure they provide will counterselect for antibiotic resistant pathogens. 

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