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Products of aminolysis and enzymic hydrolysis of the cephalosporins.

ABSTRACT: 1. The reaction of cephalosporins with ammonia, amino acids and other simple amino compounds in weakly alkaline aqueous solutions yields labile compounds with lambda(max.) 230nm. The reaction of deacetyl- and deacetoxy-cephalosporins under similar conditions yields compounds with lambda(max.) 260nm. 2. Hydrolysis with a beta-lactamase results in the formation of compounds with lambda(max.) 230nm from deacetylcephalosporins and cephalosporins, but not from deacetoxycephalosporins. 3. These different compounds decompose to give penaldates and penamaldates derived from the side chain and the carbon atoms of the beta-lactam ring. 4. Derivatives similar to those obtained with simple amino compounds appear to be formed when cephalosporins and their analogues react with lysine polymers. 5. Some of the chemical and physical properties of the various derivatives have been studied and tentative structures for them are proposed. 6. Possible implications of the results in relation to the immunological properties of the cephalosporins are discussed.

SUBMITTER: Hamilton-Miller JM

PROVIDER: S-EPMC1185375 | biostudies-other | 1970 Feb

REPOSITORIES: biostudies-other

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Project description:Extended-spectrum ?-lactamase (ESBL)-producing Salmonella are one of the most important public health problems in developed countries. ESBL-producing Salmonella strains have been isolated from humans in Asian countries neighboring Japan, along with strains harboring the plasmid-mediated extended-spectrum cephalosporin (ESC)-resistance gene, ampC (pAmpC). However, only a few studies have investigated the prevalence of ESC-resistant Salmonella in chicken products in Japan, which are the main vehicle of Salmonella transmission. The aim of this study was to investigate the prevalence of ESBL-producing, pAmpC-harboring, or carbapenem-resistant Salmonella in chicken products in Japan. In total, 355 out of 779 (45.6%) chicken product samples collected from 1996-2010 contained Salmonella, resulting in 378 distinct isolates. Of these isolates, 373 were tested for resistance to ESCs, cephamycins, or carbapenems. Isolates that showed resistance to one or more of these antimicrobials were then examined by PCR and DNA sequence analysis for the presence of the bla(CMY), bla(CTX-M), bla(TEM), and bla(SHV) resistance genes. Thirty-five resistant isolates were detected, including 26 isolates that contained pAmpC (bla(CMY-2)), and nine ESBL-producing isolates harboring bla(CTX-M) (n = 4, consisting of two bla(CTX-M-2) and two bla(CTX-M-15 genes)), bla(TEM) (n = 4, consisting of one bla(TEM-20) and three bla(TEM-52) genes), and bla(SHV) (n = 1, bla(SHV-12)). All pAmpC-harboring and ESBL-producing Salmonella isolates were obtained from samples collected after 2005, and the percentage of resistant isolates increased significantly from 0% in 2004 to 27.9% in 2010 (P for trend = 0.006). This increase was caused in part by an increase in the number of Salmonella enterica subsp. enterica serovar Infantis strains harboring an approximately 280-kb plasmid containing bla(CMY-2) in proximity to ISEcp1. The dissemination of ESC-resistant Salmonella containing plasmid-mediated bla(CMY-2) in chicken products indicates the need for the development of continuous monitoring strategies in the interests of public health.

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Products of aminolysis and enzymic hydrolysis of the cephalosporins.

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