الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
The term antibiotics traditionally refers to substances produced by a microorganism to inhibit the growth or viability of another microorganism(1, 2). Thus the distinction between the terms antibiotics and antimicrobial agents is somewhat blurred and has little meaning; many physicians use the terms interchangeably(1). Antimicrobial agents may be classified according to the type of organism against which they are active; consequently they include antibacterial, antiviral, antifungal antiprotozoal and anthelmintic agents(3). Antimicrobial agents encompass drugs synthesized in the laboratory as well as those natural antibiotics produced by microorganisms. Some natural antibiotics originally produced by microbial fermentation are now produced by chemical synthesis. Many agents are semi-synthetic; that is, the key portion of the compound is produced by microbial fermentation, and various moieties are attached synthetically(1). Antimicrobials are used for treatment and for prophylaxis against infections in humans and animals, for growth promotion in food animal rearing, and in agriculture(4).
Antibiotics are one of the most important medical discoveries and major scientific achievements of the 20th century(5, 6). The development of such agents during the past 80 years constitutes one of the most important therapeutic advances in the history of medicine(7). The 20th century has seen an almost complete transformation in our understanding and treatment of infectious diseases(8). Such diseases account for almost one in two premature deaths worldwide(9). Indeed mortality as a result of infectious diseases represents one-fifth of global deaths(10, 11). Infectious diseases also account for 45% of deaths in low-income countries(6), and 85% of these deaths are due to five diseases: acute respiratory infections, diarrhoeal disease, HIV/AIDS, tuberculosis and malaria(12-14). Infectious diseases represent 7 out of 10 top causes of child deaths in developing countries, and account for nearly 60% of all such deaths(15).
Since the introduction of these ”wonder drugs”, antimicrobials (antibiotics) have played, in combination with immunization and improved hygiene(6), an essential role in decreasing morbidity and mortality due to infectious diseases(4, 16). Antibiotics have revolutionized the treatment of common bacterial infections and play a crucial role in reducing child mortality in low-income countries (WHO 2000)(6). Infected cuts and wounds are no longer life-threatening, and various bacterial diseases, such as syphilis and cholera, are considered on their way to eradication(5). The dramatic fall in morbidity from communicable and infectious diseases over the last 50 years globally is due to increasingly high levels of expenditure on and consumption of antimicrobials(17). In addition to benefits for the individual, antimicrobials have a public health benefit by reducing the burden of a number of important diseases(18).