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Itzhak Brook, in Principles and Practice of Pediatric Infectious Diseases (Fifth Edition), 2018 Chronic Tonsillitis.ĪGNB can be involved in acute tonsillitis, chronic tonsillitis, and their complications, including internal jugular vein thrombophlebitis. However, its validity was challenged by the observations of Vaara (1993), who found no cross-resistance between polymyxin, a compound which utilizes a selfpromoted penetration through the outer membrane, and azithromycin. This observation may constitute a basis for the design of newer macrolides with improved activity against gram-negative bacteria.
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Thus the polycationic nature of azithromycin enables it to competitively displace divalent cations from lipopolysaccharides in gram negative outer membrane, thereby increasing its own permeability. Studies ( Farmer et al., 1992) indicate that macrolides cannot gain access into gram-negative bacteria via porins and that the new analog azithromycin, which has improved activity against gram-negative bacteria, may be gaining access via a self-promoted access pathway. Gram-negative bacteria are inherently resistant to macrolide antibiotics, presumably due to the sizes of the molecules (molecular weights of > 600) and their hydrophobicities. Tanaka, in Advances in Pharmacology, 1994 A Inherent Gram-Negative Resistance