antibiotic sensitivity test

antibiotic sensitivity test,

a laboratory method for determining the susceptibility of organisms to therapy with antibiotics. After the infecting organism has been recovered from a clinical specimen, it is cultured and tested against a panel of antibiotic drugs (the specific panel is determined by whether the organism is gram-positive and gram-negative). If the growth of the organism is inhibited by the action of the drug, it is reported as sensitive to that antibiotic. If the organism is not susceptible to the antibiotic, it is reported as resistant to that drug. See also sensitivity test.

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antibiotic

1. destructive of life.

2. a chemical substance produced by a microorganism that has the capacity, in dilute solutions, to kill (biocidal activity) or inhibit the growth (biostatic activity) of other microorganisms. Antibiotics that are sufficiently nontoxic to the host are used as chemotherapeutic agents in the treatment of infectious diseases. See also antimicrobial.

3. used as feed additives to animals as growth promotants.

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anthracycline a's

a group of antibiotics which have a tetracycline ring structure substituted with the sugar daunosamine. Includes the antineoplastic drugs doxorubicin and daunorubicin.

antineoplastic antibiotic

see antineoplastic.

bactericidal antibiotic

one that kills bacteria.

bacteriostatic antibiotic

one that suppresses the growth of bacteria.

broad-spectrum antibiotic

one that is effective against a wide range of bacteria.

antibiotic detection

on-farm and prepackaged laboratory tests available for testing farm products and animal tissues and fluids for antibiotic residues.

antibiotic drugs

the range includes the following groups: penicillin, aminoglycoside, tetracycline, chloramphenicol, macrolide, nitrofuran, cephalosporins, and a miscellaneous group including bacitracin, tyrothricin, polymyxin, colistin.

antibiotic feed additives

see feed additives.

first generation antibiotic

one produced as a natural product, e.g. penicillin G. See second generation antibiotic (below).

antibiotic food preservation

is a satisfactory technique but very strictly controlled because of the problem of residues in the food. Used mostly for the preservation of fish.

antibiotic-induced diarrhea

see pseudomembranous colitis, acute undifferentiated diarrhea of the horse.

antibiotic residue in food

in human food of animal origin is a seriously regarded pollution in public health surveillance. The residues may arise from systemic administration, or even after absorption from a local site such as the uterus, but the most serious contamination arises from milk from quarters that have been treated for mastitis. It is essential for the safety of the human population, the financial well-being of the farmer and the professional reputation of the veterinarian that antibacterial withdrawal times are observed.

antibiotic resistance

see antimicrobial resistance.

second generation antibiotic

produced by manipulation of the molecular structure of a first generation antibiotic (see above) so that the metabolism and pharmacodynamics of the original compound are significantly altered.

antibiotic sensitivity test

see antimicrobial sensitivity test.

antibiotic therapy

antibiotics vary in their absorption from the alimentary tract, requiring some, e.g. streptomycin, to be given parenterally for systemic effect, freedom from toxicity, the range of bacteria against which they are effective, their capacity to stimulate resistance and whether they are bacteriostatic or bactericidal in their effects. Selection of the most suitable antibiotic to suit a particular circumstance may be guided by an antimicrobial sensitivity test, knowledge of the infection present and the price of the drug. In many instances, because of lack of knowledge of the infection present it is necessary to choose an agent with a broad antibacterial spectrum.

antibiotic withdrawal, antibiotic withholding

see antibacterial withdrawal time.