In vitro selection of RNA aptamer against Escherichia coli release factor 1

ABSTRACT We report on a novel CTX-M extended-spectrum β-lactamase (ESBL), designated CTX-M-42, with enhanced activity toward ceftazidime. CTX-M-42 was identified in a hypermutable Escherichia coli nosocomial isolate (isolate Irk2320) and is a Pro167Thr amino acid substitution variant of CTX-M-3. By molecular typing of ESBL-producing E. coli strains previously isolated in the same hospital ward, we were able to identify a putative progenitor (strain Irk1224) of Irk2320, which had a mutator phenotype and harbored the CTX-M-3 β-lactamase. To reproduce the natural evolution of CTX-M-3, we selected for ceftazidime resistance mutations in bla CTX-M-3 gene in vitro both in clinical isolate Irk1224 and in laboratory-derived hypermutable (mutD5) strain GM2995. These experiments yielded CTX-M-3Pro167Ser and CTX-M-3Asn136Lys mutants which conferred higher levels of resistance to ceftazidime than to cefotaxime. CTX-M-3Asn136Lys had a level of low activity toward ampicillin, which may explain its absence from clinical isolates. We conclude that the selection of CTX-M-42 could have occurred in vivo following treatment with ceftazidime and was likely facilitated by the hypermutable background.

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In vitro selection of a photoresponsive RNA aptamer to hemin

Bioorganic & Medicinal Chemistry Letters ◽

10.1016/j.bmcl.2010.02.109 ◽

2010 ◽

Vol 20 (9) ◽

pp. 2964-2967 ◽

Cited By ~ 20

Author(s):

Mingzhe Liu ◽

Hiroshi Jinmei ◽

Hiroshi Abe ◽

Yoshihiro Ito

Keyword(s):

In Vitro Selection ◽

Rna Aptamer ◽

Selection Of

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In vitro selection of resistance to pradofloxacin and ciprofloxacin in canine uropathogenic Escherichia coli isolates

Veterinary Microbiology ◽

10.1016/j.vetmic.2014.10.011 ◽

2014 ◽

Vol 174 (3-4) ◽

pp. 514-522 ◽

Cited By ~ 6

Author(s):

Xiaoqiang Liu ◽

Caterina Lazzaroni ◽

Sherine A. Aly ◽

Kamoltip Thungrat ◽

Dawn M. Boothe

Keyword(s):

Escherichia Coli ◽

In Vitro Selection ◽

Uropathogenic Escherichia Coli ◽

Selection Of ◽

Selection Of Resistance

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In Vitro Selection of RNA Aptamer and Specific Targeting of ErbB2 in Breast Cancer Cells

Nucleic Acid Therapeutics ◽

10.1089/nat.2011.0283 ◽

2011 ◽

Vol 21 (3) ◽

pp. 173-178 ◽

Cited By ~ 56

Author(s):

Mee Young Kim ◽

Sunjoo Jeong

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Breast Cancer Cells ◽

In Vitro Selection ◽

Rna Aptamer ◽

Specific Targeting ◽

Selection Of

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CTX-M Expression and Selection of Ertapenem Resistance in Klebsiella pneumoniae and Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01007-08 ◽

2008 ◽

Vol 53 (2) ◽

pp. 832-834 ◽

Cited By ~ 37

Author(s):

Delphine Girlich ◽

Laurent Poirel ◽

Patrice Nordmann

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

In Vitro Selection ◽

Gene Frequencies ◽

Clinical Strains ◽

Selection Of

ABSTRACT In vitro selection of mutants with decreased susceptibility to ertapenem was performed using Escherichia coli and Klebsiella pneumoniae clinical strains producing either the bla CTX-M-2, bla CTX-M-3, bla CTX-M-9, or bla CTX-M-15 gene. Frequencies of mutants with decreased susceptibilities to ertapenem were similar for all β-lactamases expressed.

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