Β-lactam antibiotic reactions to any β-lactam antibiotic may occur in up to 10% of patients receiving that agent (a small fraction of which are truly IgE-mediated allergic reactions, see amoxicillin rash). Anaphylaxis will occur in approximately 0.01% of patients. There is perhaps a 5%-10% cross-sensitivity between penicillin-derivatives, cephalosporins, and carbapenems; but this figure has been challenged by various investigators. Nevertheless, the risk of cross-reactivity is sufficient to warrant the contraindication of all β-lactam antibiotics in patients with a history of severe allergic reactions (urticaria, anaphylaxis, interstitial nephritis) to any β-lactam antibiotic. A Jarisch–Herxheimer reaction may occur after initial treatment of a spirochetal
Antibiotic resistance in gonorrhea the "parC" gene which encodes for the topoisomerase IV. Topoisomerase IV acts similarly to DNA gyrase and is involved in unwinding DNA for replication. Ceftriaxone and cefixime are third generation cephalosporins and are often used as treatments for "N. gonorrhoeae infections". The cephalosporins are part of a larger beta-lactam family of antibiotics. The newly discovered H041 strain of "N. gonorrhoeae", originally isolated from a commercial sex worker in Japan, was shown to be resistant to this antibiotic. The possible mechanisms of resistance to this antibiotic are as follows: Tetracyclines are a class of antibiotics that inhibit protein synthesis by binding