Diversity of SHV and TEM β-Lactamases in Klebsiella pneumoniae : Gene Evolution in Northern Taiwan and Two Novel β-Lactamases, SHV-25 and SHV-26

Author:

Chang Feng-Yee1,Siu L. K.2,Fung Chang-Phone3,Huang Min-Hua1,Ho Monto2

Affiliation:

1. Division of Infectious Disease and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center,1

2. Division of Clinical Research, National Health Research Institute,2 and

3. Section of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, and National Yang-Ming University,3 Taipei, Taiwan

Abstract

ABSTRACT A total of 113 blood culture isolates of Klebsiella pneumoniae from 10 hospitals in northern Taiwan were studied for SHV and TEM β-lactamase production. bla SHV was amplified from all isolates by PCR. TEM-type resistance, was found in 32 of the isolates and was of the TEM-1 type in all isolates. SHV-1, -2, -5, -11, and -12 and two novel enzymes were identified. These novel enzymes were designated SHV-25 and SHV-26 and had pIs of 7.5 and 7.6, respectively. Amino acid differences in comparison to the amino acid sequence of bla SHV-1 were found at positions T18A (ThrACC→AlaGCC), L35Q (LeuCTA→GluCAA), and M129V (MetATG→ValGTG) for SHV-25 and at position A187T (AlaGCC→ThrACC) for SHV-26. The results of substrate profiles and MIC determinations showed that the novel enzymes did not hydrolyze extended-spectrum cephalosporins, rendering the isolates susceptible to these agents. Inhibition profiles revealed that the 50% inhibitory concentration for SHV-26 was higher than those for SHV-1 and SHV-25, resulting in an intermediate resistance to amoxicillin-clavulanic acid. Forty-nine ribotypes were identified, suggesting that major clonal spread had not occurred in any of the hospitals. According to the amino acid sequence, SHV β-lactamases in Taiwan may basically be derived through stepwise mutation from SHV-1 or SHV-11 and further subdivided by four routes. The stepwise mutations initiated from SHV-1 or SHV-11 to SHV-2, SHV-5, and SHV-12 comprise the evolutionary change responsible for extended-spectrum β-lactamase (ESBL) production in Taiwan. The stepwise mutations that lead to a non-ESBL (SHV-25) and the β-lactamase (SHV-26) with reduced susceptibility to clavulanic acid are possibly derived from SHV-11 and SHV-1, respectively. The results suggest a stepwise evolution of SHV β-lactamases in Taiwan.

Publisher

American Society for Microbiology

Subject

Infectious Diseases,Pharmacology (medical),Pharmacology

Cited by 57 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3