What is lactam structure?

A lactam is a cyclic amide, formally derived from an amino alkanoic acid. The term is a portmanteau of the words lactone + amide.

What is the mechanism of action of beta-lactams?

Mechanism of action β-lactam antibiotics are bactericidal, and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls. The peptidoglycan layer is important for cell wall structural integrity, especially in Gram-positive organisms, being the outermost and primary component of the wall.

What are beta lactamases What is its function?

The beta-lactamase enzymes inactivate beta-lactam antibiotics by hydrolyzing the peptide bond of the characteristic four-membered beta-lactam ring rendering the antibiotic ineffective. The inactivation of the antibiotic provides resistance to the bacterium.

What are beta-lactams examples?

β-lactam antibiotics, including penicillins and cephalosporins, inhibit platelet aggregation responses, and some can induce a bleeding diathesis when given in high doses. These include carbenicillin, penicillin G, ticarcillin, ampicillin, nafcillin, cloxacillin, mezlocillin, oxacillin, and piperacillin.

What is beta-lactam?

Medical Definition of beta-lactam : any of a large class of natural and semisynthetic antibiotics (as the penicillins and cephalosporins) with a lactam ring.

Is amoxicillin a beta-lactam?

Amoxicillin is a beta-lactam antibiotic active against gram-positive cocci, including nonpenicillin resistant streptococcal, staphylococcal, and enterococcal species.

Are beta lactams bactericidal or bacteriostatic?

β-Lactam antibiotics are bactericidal agents that interrupt bacterial cell-wall formation as a result of covalent binding to essential penicillin-binding proteins (PBPs), enzymes that are involved in the terminal steps of peptidoglycan cross-linking in both Gram-negative and Gram-positive bacteria.

How does B lactams affect and destroy bacteria?

Penicillin kills bacteria through binding of the beta-lactam ring to DD-transpeptidase, inhibiting its cross-linking activity and preventing new cell wall formation. Without a cell wall, a bacterial cell is vulnerable to outside water and molecular pressures, which causes the cell to quickly die.

Is erythromycin A beta-lactam?

Beta-lactam antibiotics, the tetracyclines, chloramphenicol, erythromycin, clindamycin, metronidazole, and the quinolones.

Where is beta-lactamase made in the cell?

Gram-positive bacteria that make beta-lactamase excrete the enzyme into the extracellular space. Gram-negative bacteria excrete beta-lactamase into the periplasmic space located between the cytoplasmic membrane & the outer membrane, where the cell wall is located.

Is imipenem a carbapenem?

Imipenem/cilastatin is the first of a new class of beta-lactam antibiotics called carbapenems. The antibacterial spectrum of imipenem exceeds any antibiotic investigated to date and includes gram-positive, gram-negative, and anaerobic organisms.

Is Penicillin a beta-lactam?

Beta-lactam antibiotics include penicillins, cephalosporins and related compounds. As a group, these drugs are active against many gram-positive, gram-negative and anaerobic organisms.

Is cephalexin a beta-lactam?

Cephalexin is a first-generation, cephalosporin antibiotic. It belongs to a bigger classification of antibiotics known as beta-lactam antibiotics. It is generally effective against bacteria involved in upper and lower respiratory tract infections, otitis media, mastitis, and skin, bone, and joint infections.

What are some common macrolides?

Macrolides are a class of antibiotic that includes erythromycin, roxithromycin, azithromycin and clarithromycin. They are useful in treating respiratory, skin, soft tissue, sexually transmitted, H. pylori and atypical mycobacterial infections.

Is zosyn a beta-lactam?

Piperacillin-tazobactam is a beta-lactam/beta-lactamase inhibitor combination with a broad spectrum of antibacterial activity that includes Gram-positive and -negative aerobic and anaerobic bacteria.

Are beta lactams bactericidal?

β-Lactam antibiotics have a β-lactam ring in their molecular structure (Figure 8-1). They include penicillins, cephalosporins, monobactams, and carbapenems. They are bactericidal antibiotics (see Chapter 6) that bind covalently to and inhibit penicillin binding proteins (PBPs).

What is the target for clavulanic acid?

Clavulanic acid contains a beta-lactam ring and binds strongly to beta-lactamase at or near its active site, thereby hindering enzymatic activity. This protects other beta-lactam antibiotics from beta-lactamase catalysis, thereby enhancing their antibacterial effects.

Is ceftriaxone a beta-lactam?

Ceftriaxone (CEF) is a third generation cephalosporin, under the group of β-lactam antibiotics, and is the most frequently used drug for local (skin and soft tissue infections) as well as systemic community and hospital-acquired infections (Pinto Pereira et al., 2004).

Is ampicillin a beta-lactam?

β-Lactam Group of Antimicrobials β-Lactam antibiotics include penicillins, oxacillin, amoxicillin, ampicillin, carbpenicillin, and others.

Is cloxacillin a beta-lactam?

Amoxicillin, Amoxicillin combined with clavulanate, Penicillin V, Cloxacillin, Cephalexin and Cefuroxime belong to a group of medicines which are used to treat bacterial infection known as beta lactams.

Is Augmentin bactericidal or bacteriostatic?

Microbiology: Amoxicillin is a semisynthetic antibiotic with a broad spectrum of bactericidal activity against many gram-positive and gram-negative microorganisms.

Is vancomycin a glycopeptide?

Vancomycin is a glycopeptide antibiotic primarily active against gram-positive bacteria. It also inhibits cell wall synthesis by binding to the bacterial d-Ala-d-Ala peptidoglycan binding site, preventing cross-linking and causing lysis.

Why macrolides are bacteriostatic?

Mechanism of action Macrolide antibiotics do so by binding reversibly to the P site on the 50S subunit of the bacterial ribosome. This action is considered to be bacteriostatic. Macrolides are actively concentrated within leukocytes, and thus are transported into the site of infection.

Are aminoglycosides beta lactams?

The beta lactam antibiotics (e.g. penicillins, cephalosporins) and the aminoglycosides (e.g. gentamicin) kill bacteria by different means.

How do beta lactams prevent cell wall synthesis?

β-Lactam antibiotics are bacteriocidal and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls. The final step in the synthesis of the peptidoglycan is facilitated by penicillin-binding proteins (PBPs). PBPs vary in their affinity for binding penicillin or other β-lactam antibiotics.

How do beta lactams stop bacteria from reproducing?

Beta-lactams disrupt PG biogenesis by inactivating enzymes called penicillin-binding proteins (PBPs) (Tipper and Strominger, 1965). Bacteria encode a variety of PBPs that participate in PG assembly (Sauvage et al., 2008). The high-molecular weight PBPs are the major PG synthases.

What are B lactams and why are they important for selection of antibiotic treatment?

β-Lactams represent one of the most important groups of antibiotics prescribed for antibacterial treatment today. They stop bacterial growth by inhibiting PBPs that are indispensable for the cross-linking process during cell wall biosynthesis.

Is azithromycin a macrolide?

Azithromycin and clarithromycin are derivatives of the older macrolide antibiotic erythromycin. They are used in the treatment of a variety of infections, including community-acquired respiratory tract infections and mycobacterial infections.

Is bactrim a beta-lactam?

Augmentin and Bactrim are different types of antibiotics. Augmentin is a combination penicillin-type antibiotic and a beta-lactamase inhibitor and Bactrim is a combination of an anti-bacterial sulfonamide (a sulfa drug) and a folic acid inhibitor.

Is cefdinir a beta-lactam?

Cefdinir (Omnicef) and amoxicillin (Amoxil) are two antibiotics used to treat bacterial infections. Both drugs are part of a group of antibiotics called beta-lactams. They can treat a range of different infections such as respiratory tract infections, ear infections, and skin infections.