Study Of OXA Extended Spectrum β-lactamases(ESBLs)

Objective:ESBLs had been extensively investigated and studied since it was discovered. The enzyme can be inhibited by β-lactamase inhibitors(for example Clavulanic acid) and it can hydrolyze oxyimineo-lactam antibiotics ceftazidime, cefotaxime and aztreonam via plasmid. Its character is that hydrolyze the third and the forth era cephalothin deeply. The enzyme mostly produced by E.coli and K.Pneumoniae originally. But along with the plasmid transmitting from one bacteria to another, it can be inspected in more species of bacteria, for example E.aerogenes,E.cloacac,P.vulgaris, C.freundii in Enterobactericaeae;P.aeruginosa, Stenotrophomonas maltophilia in Nonfermenters Gram negative bacteria. Besides that, the species of ESBLs are increasing now. More than ten species and 200 sub-species had been discovered as TEM,SHV, CTX, OXA, MOX, CMY, FOX, MIR, LAT, BIL, BES, IBC, GES, VEB, PER etc. There are big different among every species of ESBLs' molecular structure. The antibiotics endurance because of it is more and more complex. So to study every species of ESBLs has become a important task for every clinical laboratory workers all over the world now. At present, there have been a lot of researches about every subtype of ESBLs in foreign countries.As terrain , environment medical level and usage of antibiotics are very different, the epidemic of ESBLs are different. At the same time, there are a lot of researches and studies about ESBLs in some areas in our country too. But up to now, most studies in China are...