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  • 1 Chinese Academy of Sciences Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics 457 Zhongshan Road Dalian 116023 P.R. China
  • | 2 Graduate School of the Chinese Academy of Sciences Beijing 100049 P.R. China
  • | 3 Chinese Academy of Sciences Division of Biotechnology, Dalian Institute of Chemical Physics 457 Zhongshan Road Dalian 116023 P.R. China
  • | 4 Dalian Institute of Drug Detection Dalian 116021 P.R. China
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Abstract  

Microcalorimetry was applied to study the effect of cephalosporins (cefazolin sodium and cefonicid sodium) on the E. coli growth. The microbial activity was recorded as power-time curves through an ampoule method with a TAM Air Isothermal Microcalorimeter at 37°C. The parameters such as the growth rate constant (k), inhibitory ratio (I), the maximum power output (Pm) and the time corresponding to the maximum power output (tm) were calculated. The change tendencies of k, with the increasing of concentration (C) of the two cephalosporins, are similar which show that cefazolin sodium and cefonicid sodium have the same inhibitory mechanism. The experimental results reveal that cefonicid sodium has a stronger antibacterial activity towards E. coli than that of cefazolin sodium and this was coincide with the clinical manifestations.