Characterization of enterohemorrhagic Escherichia coli strains based on acid resistance phenotypes

被引:51
作者
Bhagwat, AA
Chan, L
Han, R
Tan, J
Kothary, M
Jean-Gilles, J
Tall, BD
机构
[1] USDA, Prod Qual & Safety Lab, Henry A Wallace Beltsville Agr Res Ctr, ARS, Beltsville, MD 20705 USA
[2] US FDA, Div Virulence Assessment, Laurel, MD 20708 USA
关键词
D O I
10.1128/IAI.73.8.4993-5003.2005
中图分类号
R392 [医学免疫学]; Q939.91 [免疫学];
学科分类号
100102 ;
摘要
Acid resistance is perceived to be an important property of enterohemorrhagic Escherichia coli strains, enabling the organisms to survive passage through the acidic environment of the stomach so that they may colonize the mammalian gastrointestinal tract and cause disease. Accordingly, the organism has developed at least three genetically and physiologically distinct acid resistance systems which provide different levels of protection. The glutamate-dependent acid resistance (GDAR) system utilizes extracellular glutamate to protect cells during extreme acid challenges and is believed to provide the highest protection from stomach acidity. In this study, the GDAR system of 82 pathogenic E. coli isolates from 34 countries and 23 states within the United States was examined. Twenty-nine isolates were found to be defective in inducing GDAR under aerobic growth conditions, while five other isolates were defective in GDAR under aerobic, as well as fermentative, growth conditions. We introduced rpoS on a low-copy-number plasmid into 26 isolates and were able to restore GDAR in 20 acid-sensitive isolates under aerobic growth conditions. Four isolates were found to be defective in the newly discovered LuxR-like regulator GadE (formerly YhiE). Defects in other isolates could be due to a mutation(s) in a gene(s) with an as yet undefined role in acid resistance since GadE and/or RpoS could not restore acid resistance. These results show that in addition to mutant alleles of rpoS, mutations in gadE exist in natural populations of pathogenic E. coli. Such mutations most likely alter the infectivity of individual isolates and may play a significant role in determining the infective dose of enterohemorrhagic E. coli.
引用
收藏
页码:4993 / 5003
页数:11
相关论文
共 52 条
  • [1] Global analysis of Escherichia coli gene expression during the acetate-induced acid tolerance response
    Arnold, CN
    McElhanon, J
    Lee, A
    Leonhart, R
    Siegele, DA
    [J]. JOURNAL OF BACTERIOLOGY, 2001, 183 (07) : 2178 - 2186
  • [2] Breaking through the acid barrier: An orchestrated response to proton stress by enteric bacteria
    Audia, JP
    Webb, CC
    Foster, JW
    [J]. INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY, 2001, 291 (02) : 97 - 106
  • [3] Benito A, 1999, APPL ENVIRON MICROB, V65, P1564
  • [4] Comparative analysis of transcriptional regulatory elements of glutamate-dependent acid-resistance systems of Shigella flexneri and Escherichia coli O157:H7
    Bhagwat, AA
    Bhagwat, M
    [J]. FEMS MICROBIOLOGY LETTERS, 2004, 234 (01) : 139 - 147
  • [5] Regulation of the glutamate-dependent acid-resistance system of diarrheagenic Escherichia coli strains
    Bhagwat, AA
    [J]. FEMS MICROBIOLOGY LETTERS, 2003, 227 (01) : 39 - 45
  • [6] Phylogenetic evidence for horizontal transfer of mutS alleles among naturally occurring Escherichia coli strains
    Brown, EW
    LeClerc, JE
    Li, BG
    Payne, WL
    Cebula, TA
    [J]. JOURNAL OF BACTERIOLOGY, 2001, 183 (05) : 1631 - 1644
  • [7] Influence of incubation conditions on survival and acid tolerance response of Escherichia coli O157:H7 and non-O157:H7 isolates exposed to acetic acid
    Brudzinski, L
    Harrison, MA
    [J]. JOURNAL OF FOOD PROTECTION, 1998, 61 (05) : 542 - 546
  • [8] Control of acid resistance in Escherichia coli
    Castanie-Cornet, MP
    Penfound, TA
    Smith, D
    Elliott, JF
    Foster, JW
    [J]. JOURNAL OF BACTERIOLOGY, 1999, 181 (11) : 3525 - 3535
  • [9] rpoS regulation of acid, heat, and salt tolerance in Escherichia coli O157:H7
    Cheville, AM
    Arnold, KW
    Buchrieser, C
    Cheng, CM
    Kaspar, CW
    [J]. APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 1996, 62 (05) : 1822 - 1824
  • [10] Availability of glutamate and arginine during acid challenge determines cell density-dependent survival phenotype of Escherichia coli strains
    Cui, SH
    Meng, JH
    Bhagwat, AA
    [J]. APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2001, 67 (10) : 4914 - 4918