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Stack #3190751
Question | Answer |
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Antibiotics | It is produced naturally by microorganisms and kill or prevents the growth of other microorganisms, mainly bacteria. |
Antimicrobials | A drug with natural or synthetic origin that kills or inhibits the growth of microorganisms. |
Antibacterials | Any substance that kills or inhibits the growth of bacteria. |
Use of antibiotics in humans | Used mainly in humans to kill or inhibit the harmful bacteria that cause harmful or infection. |
Use of antibiotics in animals | Therapeutic use-to treat sick animals Prophylactic use- to prevent the infection Growth promoters-to increase the production |
Gram positive bacteria | Bacteria have a cell wall composed of a thick layer of a peptidologlycan substance which is bound directly to cytoplasmic membrane. |
Gram negative bacteria | Bacteria having outer membrane made of lipid bilayer over peptidoglycan membrane with greater diffusion barrier. |
Bactericidal | Antibiotics kill bacteria directly. |
Bacteriostatic | Antibiotics prevent the growth of bacteria. |
Minimal Inhibitory Concentration (MIC) | It is defined as the minimum concentration of antimicrobial needed to inhibit visible growth of a given organism |
Minimal bactericidal concentration (MBC) | It is defined as the minimum concentration of the antimicrobial needed to kill a given organism |
Narrow spectrum antibiotic | It is only kill few or specific bacteria and may useful when the bacteria growing is known. |
Broad spectrum antibiotic | It will kill many organisms and used when we are not sure what kind of bacteria is growing. |
What are the way antibiotic kill bacteria? | Interfere/inhibit the cell wall, protein, DNA and folic acid synthesis in bacteria. |
Sensitive | An organism is considered sensitive to an agent if hit is inhibited or killed by levels of the antimicrobial that are available at the site of infection |
Resistance | An organism is considered resistant if it is not killed or inhibited by levels of the antimicrobial that are available at the site of infection |
Intrinsic resistance | It is a natural resistance occur due to inability of drug to permeate bacterial cell. |
Acquired resistance | It occurs when a bacterium acquires the ability to resist the actions of a particular antibiotic. |
Multi drug resistance (MDR) | It is an antimicrobial resistance shown by a species of microorganism to multiple antimicrobial drugs. |
Beta lactam resistance | Beta-lactamases are enzymes produced by bacteria that provide multi-resistance to β-lactam antibiotics such as penicillins, cephalosporins, etc. |
Extended Spectrum Beta Lactamases (ESBLs) | ESBLs are defined as enzymes produced by certain bacteria that are able to hydrolyze or break down pencillins, early generation cephalosporin and second and third generation cephalosporin. |
Carbamenemase Producing Enterobacteriaceae (CPEs) | CPEs are defined as enzymes produced by certain bacteria that are able to hydrolyze or break down pencillins, all cephalosporin and carbapenems. |
Vancomycin Resistant Enterococci (VRE) | VRE is a type of bacteria called enterococci that have developed resistance to many antibiotics, particularly vancomycin. |
Methicillin resistant Staphylococcus aureus (MRSA) | MRSA is resistant to all beta lactam antibiotics except in the newer generation of cephalosporin with anti-MRSA activity. |
Co-resistance | It refers to the presence of resistance to more than one class of antibiotics in the same bacterial strain as might occur on a plasmid. |
Cross-resistance | It is a single resistance mechanism confers resistance to an entire class of antibiotics. |
antibiotic targets in bacteria | • The cell wall or membranes • The process that make the nucleic acids • The process that produce proteins |
Drugs which disruption of cell membrane permeability | The selective membrane permeability is disrupted by antimicrobials, ions are lost and cellular ion gradient is distorted which leads to bacteria undergoes cellular damage and death. Eg. Polymyxin B |
Drugs which degradation of cell wall and function | Beta-lactam antibiotics react with penicillin binding proteins inhibit cell wall peptidoglycan biosynthesis in bacteria. Eg. Penicillin, cephalosporins, carbapenemes, monobactam. |
Drugs which target protein synthesis | Drugs can bind to different type of bacterial ribosomal sub unit leads to inhibit protein synthesis. Eg. Tetracycline, aminoglycosides, chloramphenicol and macrolides |
Tetracycline action | Bind to 30S subunit via hydrogen bonds. Prevents associated of aminoacyl- tRNA with the ribosome. |
Aminoglycosides | Bind to 30S or both subunits mRNA misreading causes abnormal proteins to be synthesized. |
Chloramphenicol | Binds to 50S subunit and inhibits the enzyme responsible for amino acid chain elongation – peptidyl transferase. |
Macrolides | Blocks the exit of the polypeptide chain from the ribosome by binding to 23S rRNA on 50S subunit. Leads to premature dissociation of the chain from peptidyl transferase and incomplete proteins formed. |
Drugs which target nucleic acid synthesis | Drugs inhibiting the enzyme which are required for bacterial DNA synthesis. Eg. Quinolones |
Mechanism of quinolones | Inhibits bacterial DNA synthesis by blocking DNA gyrase and topoisomerase IV. Eg. Ciprofloxacine, norfloxacin |
Genes | Genes, which are made up of DNA, are the basic units that define the characteristics of every organism. |
Genome | A genome is an organism’s complete set of genes that carry the genetic instructions for building and maintaining that organism. |
Isolates | Bacteria isolated from a specimen |
Resistant isolate | An isolate that is resistant to one or more antibiotics. |
Resistance gene | A gene that gives microbes the ability to resist the effects of one or more drugs. |
Resistance mutation | A change in the normal genetic code that gives a microbe the ability to resist the effects of one or more drugs. |