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#bacterial infections

2 public questions tagged with this topic.

The presence of biofilms in bacterial infections leads to:

Biofilms represent structured multicellular communities where bacteria irreversibly attach to biotic or abiotic surfaces and embed themselves in self-produced extracellular polymeric substances composed of exopolysaccharides such as alginate and Psl, extracellular DNA released via lysis, proteins, amyloids and lipids anchored via adhesins like CsgA curlin and Bap. Within biofilm microenvironments, steep gradients of oxygen, nutrients and pH create heterogeneous populations including dormant persister cells with low metabolic activity and downregulated macromolecular synthesis that are phenotyp

Ref: Madigan et al., Brock Biology of Microorganisms, 16th ed., Chapter 19: Biofilms and Increased Antibiotic Resistance.

Which antibiotic is most effective against Gram-positive bacteria?

Gram-positive bacteria possess a uniquely thick, exposed mesh of peptidoglycan often 20 to 80 nm composed of many layers of glycan chains highly cross-linked, lacking an outer membrane that would otherwise act as permeability barrier. Vancomycin is a large hydrophilic glycopeptide of about 1449 Da with multiple aromatic rings and sugars, physicochemical properties that prevent efficient passage through porin channels and lipopolysaccharide outer membrane of Gram-negative bacteria but allow ready diffusion through porous peptidoglycan of Gram-positives. It binds non-covalently via five specific

Ref: Prescott's Microbiology, 11th ed., Chapter 8: Gram-Positive Cell Wall and Vancomycin Activity.