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Antibiotics By. Dr. Humodi A. Saeed Associate Prof. of Medical Microbiology College of Medical Lab. Science Sudan University of Science and Technology E mail address: Biotechsust@hotmail.com. Definition of Antibiotic
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AntibioticsBy Dr. Humodi A. Saeed Associate Prof. of Medical Microbiology College of Medical Lab. Science Sudan University of Science and Technology E mail address: Biotechsust@hotmail.com
Definition of Antibiotic A substance of biological, semisynthetic or synthetic origin of low molecular weight ( non-protein) produced by a fungus or bacterium as secondary metabolites that inhibits or stop growth of other microorganisms in vitro and in vivo selectively, when it used in low concentration.
It must be able to reach the part of the human body where the infection is occurring. Characteristics of Antibiotics
It should not cause the development of resistant forms of parasites. Characteristics of Antibiotics
It should not produce undesirable side effects in the host such as allergic reaction, nerve damage or irritation of the kidneys and gastrointestinal tract. Characteristics of Antibiotics
It should be given orally without inactivation by stomach acid, or by injection (parenterally) without binding to the blood proteins. Characteristics of Antibiotics
Finally, it should have a high level of solubility in the body fluids and be possible to achieve concentrations in the tissue or blood, which are sufficiently high to inhibit or kill the infectious agent. Characteristics of Antibiotics
Beta-lactam antibiotic 1. Penicillin 2. Cephalosporins 3. Carbapenems 4. Monobactams Major groups of Antibiotics
The main toxicity problem with these antibiotics is an allergic reaction that occurs because of formation of beta-lactam/serum protein conjugate that elicits an inflammatory immune response. Toxicity Problem
The beta-lactam antibiotics inhibit the last step in peptidoglycan synthesis, the transformation reaction that cross links the peptide side chains of the polysaccharide peptidoglycan backbone. Mode of Action
Some are effective against both Gram-positive and Gram-negative bacteria whereas others are more effective against Gram-positive than Gram-negative bacteria or vice versa. Spectrum