Yin Jun, Cheng Jun, Sun Zhen, Ye Ying, Gao Yu-Feng, Li Jia-Bin, Zhang Xue-Jun
Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, PR China.
Clinical Medicine Post-Doctorate Position of Anhui Medical University, Hefei, Anhui 230032, PR China.
J Med Microbiol. 2009 Jun;58(Pt 6):811-815. doi: 10.1099/jmm.0.006007-0.
Three clinical strains of Escherichia coli (p168, p517 and p667) were collected in 2006 from three hospitals in Anhui Province (China). PCR and DNA sequencing revealed that E. coli p168 carried a novel extended-spectrum beta-lactamase (ESBL), which was designated CTX-M-87. The extended-spectrum beta-lactamase which was carried by E. coli p517 and E. coli p667 was previously named CTX-M-65. The deduced amino acid sequence of CTX-M-87, with pI 9.1, differed from that of CTX-M-14 by the substitutions Ala77-->Val and Pro167-->Leu. Like CTX-M-14, CTX-M-87 had a more potent hydrolytic activity against cefotaxime than against ceftazidime and had high affinity for cefuroxime and cefotaxime. These data show that mutations at position 167 in CTX-M do not always affect catalytic activity and substrate preference.
2006年从中国安徽省的三家医院收集了三株临床大肠杆菌菌株（p168、p517和p667）。PCR和DNA测序显示，大肠杆菌p168携带一种新型超广谱β-内酰胺酶（ESBL），命名为CTX-M-87。大肠杆菌p517和大肠杆菌p667携带的超广谱β-内酰胺酶先前命名为CTX-M-65。CTX-M-87的推导氨基酸序列，其pI为9.1，与CTX-M-14的不同之处在于Ala77→Val和Pro167→Leu的替换。与CTX-M-14一样，CTX-M-87对头孢噻肟的水解活性比对头孢他啶更强，并且对头孢呋辛和头孢噻肟具有高亲和力。这些数据表明，CTX-M中第167位的突变并不总是影响催化活性和底物偏好。
