Pörnull K J, Göransson E, Rytting A S, Dornbusch K
Department of Clinical Microbiology, Karolinska Hospital, Stockholm, Sweden.
J Antimicrob Chemother. 1993 Oct;32(4):559-70. doi: 10.1093/jac/32.4.559.
Five per cent of Escherichia coli and klebsiella septicaemia isolates from the European Study Group on Antibiotic Resistance (ESGAR) study in 1987 to 1988 showed reduced susceptibility or resistance to cefotaxime, ceftazidime and/oraztreonam. Six of 15 isolates studied were susceptible to cefoxitin and MICs of cefuroxime, cefotaxime, ceftazidime and aztreonam were reduced by clavulanic acid. The isoelectric points of their beta-lactamases were in the range of 5.3-7.6. DNA hybridization showed that four of these beta-lactamases belonged to the TEM or SHV family. Transfer of cefotaxime resistance by conjugation was seen in two of the strains. Nine strains were resistant to cefoxitin (MIC > 16 mg/L) and MICs of cefuroxime, cefotaxime, ceftazidime and aztreonam were only slightly reduced in the presence of clavulanic acid. All nine strains produced at least one beta-lactamase of chromosomal origin with pI > 8.4, and four of these strains also harboured beta-lactamases with a pI range of 6.6-8.2. Cefoxitin resistance could be transferred by conjugation in one strain. Thus E. coli and Klebsiella spp. from the ESGAR septicaemia isolates were found to produce extended-spectrum beta-lactamases of both chromosomal and plasmid origin.
1987年至1988年欧洲抗生素耐药性研究小组（ESGAR）研究中分离出的5%的大肠杆菌和克雷伯菌败血症菌株对头孢噻肟、头孢他啶和/或氨曲南显示出敏感性降低或耐药。所研究的15株菌株中有6株对头孢西丁敏感，克拉维酸可降低头孢呋辛、头孢噻肟、头孢他啶和氨曲南的最低抑菌浓度（MIC）。它们的β-内酰胺酶的等电点在5.3 - 7.6范围内。DNA杂交显示这些β-内酰胺酶中有4种属于TEM或SHV家族。在其中两株菌株中观察到通过接合转移头孢噻肟耐药性。9株菌株对头孢西丁耐药（MIC>16mg/L），在克拉维酸存在下头孢呋辛、头孢噻肟、头孢他啶和氨曲南的MIC仅略有降低。所有9株菌株均产生至少一种染色体来源的pI>8.4的β-内酰胺酶，其中4株菌株还携带pI范围为6.6 - 8.2的β-内酰胺酶。头孢西丁耐药性可在一株菌株中通过接合转移。因此，发现来自ESGAR败血症分离株的大肠杆菌和克雷伯菌属产生染色体和质粒来源的超广谱β-内酰胺酶。
