Beta-Lactam Antibiotics and Their Classification

Beta-lactam antibiotics inhibit cell wall synthesis.

They lead to bacterial lysis by damaging cell wall integrity.

Beta-lactam antibiotics lack activity against atypical organisms like Mycoplasma pneumoniae and Chlamydophila pneumoniae.

<p>PBPs facilitate the cross-linking of peptidoglycans in the bacterial cell wall.</p> Signup and view all the answers

<p>Their effectiveness depends on the duration of exposure above the minimum inhibitory concentration (MIC).</p> Signup and view all the answers

<p>Inhibition leads to weakened cell walls, swelling, and eventual bacterial lysis.</p> Signup and view all the answers

<p>Beta-lactam antibiotics may cause cross hypersensitivity reactions among various drugs in this class.</p> Signup and view all the answers

<p>The activation of autolysing enzymes such as Murein Hydrolase and Autolysins enhances lethality.</p> Signup and view all the answers

<p>Itching, rashes, fever, angioedema, and rarely anaphylactic shock.</p> Signup and view all the answers

<p>The metabolic opening of the β-lactam ring creates a reactive penicilloyl group that binds with tissue proteins, forming an antigenic determinant.</p> Signup and view all the answers

<p>A maximum of 10%.</p> Signup and view all the answers

<p>Diarrhoea due to alteration in normal intestinal flora.</p> Signup and view all the answers

<p>Benzylpenicillin (Penicillin G).</p> Signup and view all the answers

<p>Convulsions.</p> Signup and view all the answers

<p>Aminopenicillins and antipseudomonal penicillins.</p> Signup and view all the answers

<p>Neutropenia.</p> Signup and view all the answers

<p>The combination enhances activity against β-lactamase producing strains of bacteria.</p> Signup and view all the answers

<p>Azlocillin and piperacillin are examples of ureidopenicillins.</p> Signup and view all the answers

<p>Pseudomonas aeruginosa is specifically mentioned as being more active against these penicillins.</p> Signup and view all the answers

<p>Inactivation of the antibiotic by beta-lactamase is one mechanism of resistance.</p> Signup and view all the answers

<p>Carbapenems are highly resistant to hydrolysis by penicillinases and cephalosporinases.</p> Signup and view all the answers

<p>They inactivate penicillins preferentially, leading to resistance against these antibiotics.</p> Signup and view all the answers

<p>Ampicillin is a narrow-spectrum penicillin primarily used against certain gram-positive bacteria.</p> Signup and view all the answers

<p>Escherichia coli and Klebsiella spp. are targets of treatment with these combinations.</p> Signup and view all the answers

<p>Cross-linking is essential for septum formation during cell division; its inhibition leads to filamentation, preventing cells from separating.</p> Signup and view all the answers

<p>Penicillin is more effective against Gram-positive bacteria due to their thick peptidoglycan layer, which is easily accessible to beta-lactam antibiotics.</p> Signup and view all the answers

<p>The outer membrane of Gram-negative bacteria contains lipopolysaccharides and narrow porin channels, which act as a barrier to the permeability of antibiotics.</p> Signup and view all the answers

<p>Hydrophilic penicillins diffuse through the porin channels of Gram-negative bacteria, allowing them to exert their antimicrobial effects.</p> Signup and view all the answers

<p>Peptidoglycan is unique to bacteria and provides structural integrity to their cell walls, making it a prime target for antibiotics that interfere with its synthesis.</p> Signup and view all the answers

<p>Natural resistance in Gram-negative bacteria occurs due to deeply located target enzymes and penicillin-binding proteins (PBPs) shielded by a lipoprotein barrier.</p> Signup and view all the answers

<p>Acquired resistance can occur through the production of beta-lactamase, alteration of porin channels, or modifications of PBPs that lower their affinity for penicillin.</p> Signup and view all the answers

<p>Common organisms producing beta-lactamase include Staphylococcus, Bacillus subtilis, Gonococci, E. coli, Enterococci, and Haemophilus influenzae.</p> Signup and view all the answers

<p>It is indicated for minor infections such as tonsillitis.</p> Signup and view all the answers

<p>BPG provides prolonged drug levels for effective secondary prophylaxis against rheumatic fever.</p> Signup and view all the answers

<p>They are indicated for infections caused by beta-lactamase-producing staphylococci.</p> Signup and view all the answers

<p>Aminopenicillins have an amino side group that enhances their ability to penetrate gram-negative bacteria.</p> Signup and view all the answers

<p>They are both vulnerable to destruction by beta-lactamases.</p> Signup and view all the answers

<p>The recommended dosage is 2.4 million units IM once a week for 1–3 weeks.</p> Signup and view all the answers

<p>Food can reduce the absorption rate of isoxazolyl penicillins, making them less effective.</p> Signup and view all the answers

<p>The addition of a hydroxyl group (−OH) increases its acid stability.</p> Signup and view all the answers