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Cefoxitin, Cefotetan, and Other Cephamycins
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
The cephamycins are often referred to as second-generation cephalosporin antibiotics, although they differ quite markedly from antibiotics such as cefuroxime or cefaclor. A primary attribute of the cephamycins is their resistance to a variety of beta-lactamase types, such as the extended-spectrum beta-lactamase (ESBLs) and their narrower-spectrum parents, TEM and SHV beta-lactamases. The cephamycins to be discussed in this chapter are cefotetan and cefoxitin primarily, with secondary discussion of cefmetazole and flomoxef.
Cephalosporins
Published in Thomas T. Yoshikawa, Shobita Rajagopalan, Antibiotic Therapy for Geriatric Patients, 2005
The chemistry of the cephalosporins is at once simple and complex. All but three drugs are directly derived from substitutions at the Rt or R2 positions of the cephem molecule (Fig. 1); these substitutions can alter most relevant clinical properties of the drugs, including activity, pharmacokinetics, and, to a minor degree, adverse effects. The cephamycins cefoxitin, cefotetan, and cefmetazole derive from a different fungus, Streptomyces lactamdurans, and have a substitution of a methoxy group at the 7th position. This substitution creates 7-aminocephalosporanic acid as the drug nucleus and gives these three drugs enhanced anaerobic activity which is not characteristic of the cephalosporins as a group. Because they otherwise behave as cephalosporins, for clinical considerations the cephamycins are traditionally included in the cephalosporin category.
Molecular diagnosis of antimicrobial resistance in Escherichia coli
Published in Expert Review of Molecular Diagnostics, 2018
Molly E Fleece, Suporn Pholwat, Amy J Mathers, Eric R Houpt
Ambler Class C/Bush-Jacoby group 1 enzymes include AmpC beta-lactamases. Whereas these enzymes have activity against penicillins, they have particularly high affinity and activity against cephalosporins, including cephamycins and oxyimino-beta-lactams, and monobactams. Class C enzymes are resistant to inhibition by beta-lactamase inhibitors [38]. Wild-type E. coli expresses low levels of chromosomally encoded AmpC enzymes constitutively. Overproduction of the chromosomal ampC gene or acquisition of a plasmid-mediated ampC gene results in higher levels of AmpC beta-lactamase production [39]. In E. coli, the most commonly identified plasmid-mediated AmpC enzyme is CMY-2 [34]. Other examples include CMY-6, LAT-1, FOX-5, and DHA-1 [39].
Management of infections caused by extended-spectrum β–lactamase-producing Enterobacteriaceae: current evidence and future prospects
Published in Expert Review of Anti-infective Therapy, 2018
Chau-Chyun Sheu, Shang-Yi Lin, Ya-Ting Chang, Chun-Yuan Lee, Yen-Hsu Chen, Po-Ren Hsueh
Although rarely used in many countries, cephamycins, such as cefmetazole and flomoxef, are known to be stable against the hydrolytic activity of ESBLs [14,133]. A comparison of cefmetazole (CMZ) to meropenem for the treatment of UTI caused by ESBL-producing Enterobacteriaceae showed no differences in clinical or microbiological cure rates or adverse events [134]. However, bacteremic patients were not included in the CMZ group in this study. A study from Japan compared CMZ to carbapenems for the treatment of bacteremia related to ESBL-producing Enterobacteriaceae, with CTX-M-9 being the predominant strain (59%). The survival rates in both groups were not significantly different (96 vs. 84%, respectively, P = 0.24) [135].
High rates of antimicrobial resistance of ESBL-producing Enterobacteriaceae isolated from clinical samples in Northeast of Brazil
Published in Infectious Diseases, 2018
Miguel Araújo Rios Neto, Vaneska Magalhães Rios, Luiza Franco Corá, Marcela Machado Fonseca, Kennio Ferreira-Paim, Fernanda Machado Fonseca
Table 1 shows the antimicrobial susceptibility profile of ESBL-producing enterobacteria. Within carbapenems, susceptibility to imipenem was found in 89.7% (n = 26) and to meropenem in 72.4% (n = 21). Among aminoglycosides, susceptibility to amikacin was 82.8% (n = 24) and to gentamicin 69.0% (n = 20). Susceptibility to nitrofurantoin (nitrofuran) and cefoxitin (cephamycin) occurred in 48.3% (n = 14) and 24.1% (n = 7), respectively.