In Vitro Selection of Small RNAs that Bind to Escherichia coli Phenylalanyl-tRNA Synthetase

1994 ◽  
Vol 242 (3) ◽  
pp. 186-192 ◽  
Author(s):  
Ellen Tinkle Peterson ◽  
Tao Pan ◽  
Julia Coleman ◽  
Olke C. Uhlenbeck
1998 ◽  
Vol 283 (3) ◽  
pp. 605-618 ◽  
Author(s):  
Haruichi Asahara ◽  
Nobukazu Nameki ◽  
Tsunemi Hasegawa

2008 ◽  
Vol 52 (4) ◽  
pp. 1297-1301 ◽  
Author(s):  
Marina N. Stepanova ◽  
Maxim Pimkin ◽  
Anatoly A. Nikulin ◽  
Varvara K. Kozyreva ◽  
Elena D. Agapova ◽  
...  

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.


2014 ◽  
Vol 174 (3-4) ◽  
pp. 514-522 ◽  
Author(s):  
Xiaoqiang Liu ◽  
Caterina Lazzaroni ◽  
Sherine A. Aly ◽  
Kamoltip Thungrat ◽  
Dawn M. Boothe

2008 ◽  
Vol 53 (2) ◽  
pp. 832-834 ◽  
Author(s):  
Delphine Girlich ◽  
Laurent Poirel ◽  
Patrice Nordmann

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.


2012 ◽  
Vol 417 (1) ◽  
pp. 414-420 ◽  
Author(s):  
Young Ju Lee ◽  
Seung Ryul Han ◽  
Jin-Soo Maeng ◽  
Yong-Jin Cho ◽  
Seong-Wook Lee

2007 ◽  
Vol 17 (5) ◽  
pp. 1216-1220 ◽  
Author(s):  
Shinsuke Sando ◽  
Atsushi Ogawa ◽  
Teruyuki Nishi ◽  
Masayoshi Hayami ◽  
Yasuhiro Aoyama

2005 ◽  
Vol 49 (1) ◽  
pp. 269-270 ◽  
Author(s):  
Atsushi Ogawa ◽  
Teruyuki Nishi ◽  
Shinsuke Sando ◽  
Yasuhiro Aoyama

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