Umaran A, Garaizar J, Gallego L, Colom K, Cisterna R
Enferm Infecc Microbiol Clin. 1989 Apr;7(4):189-94.
The aim of the present study was to determine which types of beta-lactamases codified by plasmids are transferred by conjugation from several species of enterobacteria. To this end, 352 strains of ampicillin-resistant enterobacteria from clinical samples from the Hospital Civil of Bilbao were evaluated. Their beta-lactamase activity and their capacity to transfer this capacity by conjugation were evaluated. The several types of plasmidic beta-lactamases in the strains that conjugated and in their respective transconjugants were characterized by analytic isoelectric approach, and also the sensitivity of these stains to 20 beta-lactamic antibiotics and the size of their plasmids. Twenty different types were detected, with a clear predominance of TEM 1. Type TEM 2 was found in 19% of the strains which conjugated, and much less commonly the types SHV 1, HMS 1 and a beta-lactamase of an approximate pl of 4.9 were found. The transfer of these beta-lactamases is mediated by a great variety of plasmids and is associated with variable levels of resistance to penicillins and unstable cephalosporins. The presence of betalactamases with activity on the more stable cephalosporins has not been detected.
本研究的目的是确定由质粒编码的哪些类型的β-内酰胺酶可通过结合作用从几种肠道杆菌中转移。为此，对来自毕尔巴鄂市立医院临床样本的352株耐氨苄西林肠道杆菌进行了评估。评估了它们的β-内酰胺酶活性以及通过结合作用转移这种活性的能力。通过分析等电方法对发生结合作用的菌株及其各自的接合子中几种类型的质粒β-内酰胺酶进行了表征，还检测了这些菌株对20种β-内酰胺类抗生素的敏感性及其质粒大小。共检测到20种不同类型，其中TEM 1明显占优势。在19%发生结合作用的菌株中发现了TEM 2型，较少见的是SHV 1型、HMS 1型以及一种等电点约为4.9的β-内酰胺酶。这些β-内酰胺酶的转移由多种质粒介导，并与对青霉素和不稳定头孢菌素的不同水平耐药性相关。未检测到对更稳定头孢菌素有活性的β-内酰胺酶的存在。
