Vatopoulos A C, Philippon A, Tzouvelekis L S, Komninou Z, Legakis N J
Department of Microbiology, Hippocration General Hospital, Athens, Greece.
J Antimicrob Chemother. 1990 Nov;26(5):635-48. doi: 10.1093/jac/26.5.635.
Analysis with a double-disc synergy test (DDST) of clinical isolates of Klebsiella pneumoniae and Escherichia coli during the period October 1988-September 1989 revealed that 24% of the former and 4% of the latter, mainly isolated from urine, possessed an extended-spectrum beta-lactamase. During this period no DDST was positive for isolates of other enterobacterial species. Transfer of ceftazidime resistance was demonstrated from six K. pneumoniae and two E. coli isolates resistant to third generation cephalosporins and aztreonam. Apart from one strain of K. pneumoniae, these strains harboured self-transferable multiresistance plasmids (c. 91 kb) with closely related EcoRI, HindIII, AvaII and PstI restriction patterns. These plasmids encoded an extended-spectrum beta-lactamase that conferred an unusually high level of resistance to ceftazidime and aztreonam (MIC greater than or equal to 64 mg/l). This enzyme had a pI of 8.2 and a substrate profile similar to that of the SHV-5 enzyme isolated initially in Chile, and later in France (CAZ-4). The remaining K. pneumoniae isolate harboured a transmissible multiresistance plasmid (c. 182 kb) that encoded the widely distributed SHV-2 enzyme. The resistance to cefoxitin that was observed in some of these strains was associated with outer membrane protein alterations.
对1988年10月至1989年9月期间肺炎克雷伯菌和大肠杆菌临床分离株进行双纸片协同试验（DDST）分析发现，前者24%、后者4%（主要从尿液中分离得到）携带超广谱β-内酰胺酶。在此期间，其他肠杆菌属分离株的DDST均为阴性。对6株对第三代头孢菌素和氨曲南耐药的肺炎克雷伯菌和2株大肠杆菌分离株进行了头孢他啶耐药性转移试验。除1株肺炎克雷伯菌外，这些菌株携带可自我转移的多耐药质粒（约91 kb），具有密切相关的EcoRI、HindIII、AvaII和PstI限制性酶切图谱。这些质粒编码一种超广谱β-内酰胺酶，赋予对头孢他啶和氨曲南异常高水平的耐药性（MIC大于或等于64 mg/l）。这种酶的pI为8.2，底物谱与最初在智利、后来在法国分离的SHV-5酶（CAZ-4）相似。其余肺炎克雷伯菌分离株携带一个可传播的多耐药质粒（约182 kb），编码广泛分布的SHV-2酶。在其中一些菌株中观察到的对头孢西丁的耐药性与外膜蛋白改变有关。
