AmpC β-lactamases:: what do we need to know for the future?

AmpC β-lactamases:: what do we need to know for the future?
复制标题

DOI:
10.1093/jac/dkg284
复制
发表时间:
2003-07-01
影响因子:
5.2
通讯作者:
Hanson, ND
Hanson, ND
中科院分区:
医学2区
文献类型:
--
作者:
Hanson, ND

文献摘要

被引文献

相似文献

自20世纪70年代末以来,AmpC β-内酰胺酶一直是研究的目标。这些酶中的大多数是头孢菌素酶,但能够在一定程度上水解所有β-内酰胺。1,2研究人员已经研究了诱导型和非诱导型AmpC β-内酰胺酶的特性,如物理性质、水解活性、参与染色体表达的分子机制以及酶诱导潜力的属间比较研究。1,3在20世纪80年代后期,这些诱导型染色体基因在质粒上被检测到(大多数没有诱导能力),并被转移到通常不表达这些类型的β-内酰胺酶的生物体中,如克雷伯氏菌属,大肠杆菌或沙门氏菌属。质粒编码的或“输入的”ampCβ-内酰胺酶使在医院实验室工作的临床微生物学家的工作复杂化。根据鉴定,不再将革兰氏阴性微生物视为潜在的产AmpC微生物。此外,许多临床微生物学家不知道质粒编码的AmpC β-内酰胺酶,因为表型检测充其量是困难的,并且这些β-内酰胺酶可能被错误地鉴定为超广谱β-内酰胺酶(ESBLs)。本文旨在指出我们对AmpC β-内酰胺酶的基本认识的新进展和/或差距。
AmpC β-lactamases have been a target of study since the late 1970s. Most of these enzymes are cephalosporinases but are capable of hydrolysing all β-lactams to some extent. 1, 2 Researchers have examined characteristics of both inducible and non-inducible AmpC β-lactamases such as physical properties, hydrolytic activity, the molecular mechanisms involved in chromosomal expression, and comparative studies between genera on the induction potential of the enzyme. 1, 3 In the late 1980s, these inducible chromosomal genes were detected on plasmids (most without induction capabilities) and were transferred to organisms, which typically do not express these types of β-lactamase such as Klebsiella spp., Escherichia coli, or Salmonellaspp. The plasmid-encoded or ‘imported’ampCβ-lactamase complicates the job of clinical microbiologists working in hospital laboratories. No longer can a Gram-negative organism be considered a potential AmpC-producing organism based on identification. In addition, many clinical microbiologists are unaware of plasmidencoded AmpC β-lactamases because phenotypic detection is difficult at best and these β-lactamases can be misidentified as extended spectrum β-lactamases (ESBLs). This article serves to point out new developments and/or gaps in the basic knowledge of our understanding of AmpC β-lactamases.