[Study on the beta-lactamases of the Escherichia coli HX88108 resistant to ceforperazon]

E. coli HX88108 was isolated from a patient and found to produce plasmid-encode beta-lactamases with conferring highly resistance to ceforperazone(CPZ). The beta-lactamases of the E. coli HX88108 and transformants pFC, pFT1, pFT2 and pFT3 were studied. The beta-lactamases stability test among 11 beta-lactam antibiotics showed that beta-lactamases from E. coli HX88108. pFC, pFT1, readily hydrolyzed penicillins, the first, second-generation cephalosporins and CPZ. beta-lactamases of pFT2 and pFT3 hydrolyzed penicillins more strongly than cephalosporins. On the other hand, experiments of inhibiting enzyme were carried out. The results indicated that beta-lactamases of HX88108, pTF1, pFT2 and pFT3 were inhibited by clavulanic acid(CA) and sulbactam (SBT). Enzyme of pFC was inhibited poorly by CA and SBT. Through isoelectric focusing technique, the PIs were as follows: HX88108 contained three beta-lactamases, of which the PIs were 5.25, 5.3 and 5.6 respectively; the PIs of beta-lactamases from pFT2, pFT3, were 5.3 and 5.6. pFC and pFT1 were different plasmids encoded beta-lactamases with the same PI 5.25. The results indicate that the beta-lactamases of E. coli HX88108 may be a new member in TEM farmily.