The management of infection depends on non-specific and specific therapeutic measures (see the information box) and also on techniques of prevention of infection.
| THERAPEUTIC MEASURES IN MANAGEMENT OF INFECTION |
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| Non-specific management |
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| Specific management |
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The ability of one microorganism to interfere with the growth of another is called antibiosis and is due to specific diffusible metabolic products termed antibiotics. Since the introduction of penicillin in 1940, research has produced a wide range of antibiotics. In addition, a variety of other chemotherapeutic agents such as metronidazole, trimethoprim, ciprofloxacin and isoniazid followed the demonstration of the therapeutic effects of sulphanilamide in 1935. A general term for all of these substances is antimicrobial agents. Those that kill microorganisms are referred to as bactericidal while agents that inhibit their growth are called bacteriostatic. Table 2.4 illustrates the sites and modes of action on bacteria of selected antimicrobial agents.
Effective therapy is available against all known bacteria, rickettsiae, mycoplasmas and chlamydiae. However, the evolution of antimicrobial resistance is seriously restricting treatment, and reports of total antibiotic resistance in Staph. aureus and enterococci are causing great concern. Specific antiprotozoal compounds are used in the treatment of diseases such as sleeping sickness, leishmaniasis, malaria and amoebic
| Mechanisms of action of antimicrobial agents | ||
|---|---|---|
| Site of action in bacteria | Mode of action | Antibiotic |
| Nucleic acid synthesis |
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| Protin synthesis |
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| Cell membrane function |
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| Cell wall synthesis |
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dysentery. An increasing number of drugs are available for the treatment of fungal infection. Antimicrobial agents active against viruses are now receiving great attention and use of antiherpes drugs is common and highly effective. Similarly, antiretroviral drugs have revolutionised the management of HIV.