Cefcapene inactivates chromosome-encoded class C beta-lactamases

Assessment of the Safety of Exposure to Cefcapene Pivoxil during the First Trimester of Pregnancy: A Prospective Cohort Study in Japan

Cefcapene pivoxil hydrochloride is an antibiotic often used by women who are or may be pregnant. However, the safety of exposure to it during the first trimester of pregnancy has not been assessed. In this study, we aimed to clarify the effects of exposure during the first trimester of pregnancy on maternal and fetal outcomes. Data were obtained from pregnant women who were counseled on drug use during pregnancy at two Japanese facilities from April 1988 to December 2017. The incidence of major malformations in singleton pregnancy was compared between neonates born to women who took cefcapene pivoxil hydrochloride (n = 270) and control drugs (n = 1594) during their first trimester. The adjusted odds ratio of the incidence of major malformations was calculated using multivariate logistic regression analysis adjusted for smoking during pregnancy and maternal age. The incidence of major malformations was 2.6% in the cefcapene pivoxil hydrochloride group and 1.8% in the control group. There were no significant differences in the incidence between the cefcapene pivoxil hydrochloride and control groups (adjusted odds ratio: 1.48 [95% confidence interval: 0.64-3.42], p = 0.36). This prospective cohort study showed that exposure to cefcapene pivoxil hydrochloride during the first trimester of pregnancy was not associated with increased risk of major malformations in infants. Our findings will help healthcare providers in choosing appropriate medicines.

A detailed kinetic study of Mox-1, a plasmid-encoded class C beta-lactamase

Surveys of beta-lactamases in different parts of the world show an important increase in class C beta-lactamases, thus the study of these enzymes is becoming an important issue. We created an overproduction system for Mox-1, a plasmid class C beta-lactamase, by cloning the gene encoding this enzyme, and placing it under the control of a T7 promoter, using vector pET 28a. The enzyme, purified by ion exchange chromatography, was used to obtain the molecular mass (38246), the N-terminal sequence (GEASPVDPLRPVV), and pI (8.9), and to perform a detailed kinetic study. Cephalotin was used as reporter substrate in the case of poor substrates. The kinetic study showed that benzylpenicillin, cephalotin, cefcapene and moxalactam were good substrates for Mox-1 (k(cat)/K(m) values >2.5 x 10(6) M(-1) s(-1)). On the other hand, ceftazidime and cefepime were poor substrates for this enzyme (K(m) values >200 microM). Clavulanic acid had no inhibitory effect on Mox-1 (K(m)=30.2 mM), however aztreonam behaved as an inhibitor of Mox-1 (K(i)=2.85 microM).