scholarly journals Novel extended-spectrum TEM-type beta-lactamase from an Escherichia coli isolate resistant to ceftazidime and susceptible to cephalothin.

1997 ◽  
Vol 41 (3) ◽  
pp. 715-716 ◽  
Author(s):  
C Chanal-Claris ◽  
D Sirot ◽  
L Bret ◽  
P Chatron ◽  
R Labia ◽  
...  

A novel extended-spectrum TEM-type beta-lactamase was detected in an Escherichia coli isolate which was resistant to ceftazidime and susceptible to cephalothin. The corresponding bla gene was sequenced. The deduced amino acid sequence showed the following three amino acid replacements with respect to the TEM-2 sequence: Glu-->Lys-104, Arg-->Ser-164, and Glu-->Lys-240. Since it confers a ceftazidimase-type resistance phenotype, we propose for this novel enzyme the designation CAZ-9, corresponding to TEM-46 in the sequential numbering scheme of TEM beta-lactamases.

1997 ◽  
Vol 41 (11) ◽  
pp. 2547-2549 ◽  
Author(s):  
L Bret ◽  
E B Chaibi ◽  
C Chanal-Claris ◽  
D Sirot ◽  
R Labia ◽  
...  

A novel inhibitor-resistant TEM (IRT) beta-lactamase was detected in an Escherichia coli isolate resistant to amoxicillin-clavulanate and susceptible to cephalothin. The substrate and inhibitor profiles of this beta-lactamase were similar to those of IRT-1 and IRT-2. The novel IRT's bla gene was sequenced, and the deduced amino acid sequence showed the amino acid replacement Arg for His-244 of the TEM-1 sequence. Substitutions for Arg-244 have been reported in three TEM-1 mutants: IRT-1 (which corresponds to TEM-31) (Cys), IRT-2/TEM-30 (Ser), and TEM-41 (Thr). We designated this novel beta-lactamase, which corresponds to TEM-51, IRT-15.


1996 ◽  
Vol 40 (3) ◽  
pp. 616-620 ◽  
Author(s):  
A Bauernfeind ◽  
I Stemplinger ◽  
R Jungwirth ◽  
P Mangold ◽  
S Amann ◽  
...  

Plasmidic extended-spectrum beta-lactamases of Ambler class A are mostly inactive against ceftibuten. Salmonella typhimurium JMC isolated in Argentina harbors a bla gene located on a plasmid (pMVP-5) which confers transferable resistance to oxyiminocephalosporins, aztreonam, and ceftibuten. The beta-lactamase PER-2 (formerly ceftibutenase-1; CTI-1) is highly susceptible to inhibition by clavulanate and is located at a pI of 5.4 after isoelectric focusing. The blaPER-2 gene was cloned and sequenced. The nucleotide sequence of a 2.2-kb insert in vector pBluescript includes an open reading frame of 927 bp. Comparison of the deduced amino acid sequence of PER-2 with those of other beta-lactamases indicates that PER-2 is not closely related to TEM or SHV enzymes (25 to 26% homology). PER-2 is most closely related to PER-1 (86.4% homology), an Ambler class A enzyme first detected in Pseudomonas aeruginosa. An enzyme with an amino acid sequence identical to that of PER-1, meanwhile, was found in various members of the family Enterobacteriaceae isolated from patients in Turkey. Our data indicate that PER-2 and PER-1 represent a new group of Ambler class A extended-spectrum beta-lactamases. PER-2 so far has been detected only in pathogens (S. typhimurium, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis) isolated from patients in South America, while the incidence of PER-1-producing strains so far has been restricted to Turkey, where it occurs both in members of the family Enterobacteriaceae and in P. aeruginosa.


1996 ◽  
Vol 40 (1) ◽  
pp. 260-262 ◽  
Author(s):  
P A Bradford ◽  
N V Jacobus ◽  
N Bhachech ◽  
K Bush

TEM-28 (pI 6.1), expressed by an Escherichia coli clinical isolate, is a novel beta-lactamase which hydrolyzed ceftazidime, cefotaxime, and aztreonam with rates of 25, 1.1, and 5.6, respectively, relative to that for benzylpenicillin (100). The nucleotide sequence of blaTEM-28 differed from that of blaTEM-1 by two base changes, resulting in amino acid substitutions of Arg-164 to His and Glu-240 to Lys.


1985 ◽  
Vol 229 (3) ◽  
pp. 791-797 ◽  
Author(s):  
R Bicknell ◽  
E L Emanuel ◽  
J Gagnon ◽  
S G Waley

The production and purification of a tetrameric zinc beta-lactamase from Pseudomonas maltophilia IID 1275 were greatly improved. Three charge variants were isolated by chromatofocusing. The subunits each contain two atomic proportions of zinc and (in two of the variants) one residue of cysteine. The thiol group is not required for activity, nor does it appear to bind to the metal. Replacement of zinc by cobalt, cadmium or nickel takes place at a measurable rate, and gives enzymes that are less active than the zinc enzyme. The properties of this enzyme differ from those of the other known zinc beta-lactamase, beta-lactamase II from Bacillus cereus. The amino acid sequence of the N-terminal 32 residues was determined; there is no similarity to the N-terminal sequences of other beta-lactamases.


1997 ◽  
Vol 41 (9) ◽  
pp. 2041-2046 ◽  
Author(s):  
A Bauernfeind ◽  
S Wagner ◽  
R Jungwirth ◽  
I Schneider ◽  
D Meyer

An Escherichia coli strain resistant to a broad spectrum of beta-lactams, including cephamycins, was isolated from a patient suffering from urinary tract infection. A resistance plasmid (pMVP-7) was transferred from the clinical isolate to an Escherichia coli recipient. Both strains produce a cefoxitin-hydrolyzing beta-lactamase focusing at pI 6.7. The phenotype was similar to that of a Klebsiella pneumoniae strain producing cephamycinase FOX-1, so primers were selected from the FOX-1 sequence to amplify the bla gene of the transconjugant. The PCR product obtained was sequenced. The percentage of identity of the deduced amino acid sequence with sequences of other AmpC-type beta-lactamases was 96.9% with FOX-1, 74.9% with CMY-1, and 67.7% with MOX-1. This new plasmid-mediated enzyme is most closely related to FOX-1 (11 amino acid exchanges). We therefore propose the designation FOX-2.


1986 ◽  
Vol 240 (1) ◽  
pp. 215-219 ◽  
Author(s):  
C Little ◽  
E L Emanuel ◽  
J Gagnon ◽  
S G Waley

Beta-lactamases are divided into classes A, B and C on the basis of their amino acid sequences. Beta-Lactamases were incubated at pH 4.0 with the carboxy-group reagent 1-(3-dimethylaminopropyl)-3-ethylcarbodi-imide plus a coloured nucleophile and the extents of inactivation and nucleophile incorporation were monitored. Two class A enzymes (from Bacillus cereus and Bacillus licheniformis) and two class C enzymes (from Enterobacter cloacae P99 and Pseudomonas aeruginosa) were examined. All four enzymes were inactivated, with total inactivation corresponding to the incorporation of approx. 2-3 mol of nucleophile/mol of enzyme. In the case of beta-lactamase I from Bacillus cereus, some 53% of the incorporated nucleophile was located on glutamic acid-168 in the amino acid sequence.


2008 ◽  
Vol 74 (23) ◽  
pp. 7439-7441 ◽  
Author(s):  
Patricia Poeta ◽  
Hajer Radhouani ◽  
Gilberto Igrejas ◽  
Alexandre Gonçalves ◽  
Carlos Carvalho ◽  
...  

ABSTRACT Escherichia coli isolates containing the following extended-spectrum beta-lactamases have been detected in 11 of 57 fecal samples (19.3%) in Berlengas Island seagulls: TEM-52 (eight isolates), CTX-M-1 (one isolate), CTX-M-14a (one isolate), and CTX-M-32 (one isolate). Most of the extended-spectrum beta-lactamase-positive isolates harbored class 1 or class 2 integrons, which included different antibiotic resistance gene cassettes.


1997 ◽  
Vol 41 (9) ◽  
pp. 1940-1943 ◽  
Author(s):  
R A Bonomo ◽  
J R Knox ◽  
S D Rudin ◽  
D M Shlaes

Amino acid changes that influence activity and resistance to beta-lactams and beta-lactamase inhibitors were explored by constructing the Gly238Ser and Met69Ile-Gly238Ser mutants of the OHIO-1 beta-lactamase, a class A enzyme of the SHV family. The Km values of cefotaxime and ceftazidime for OHIO-1 and Met69Ile beta-lactamases were > or = 500 microM. The Km of cefotaxime for the Gly238Ser beta-lactamase was 26 microM, and that of ceftazidime was 105 microM. The Km of cefotaxime for the Met69Ile-Gly238Ser beta-lactamase was 292 microM, and that of ceftazidime was 392 microM. For the beta-lactamase inhibitors clavulanate and sulbactam, the apparent Ki values for the Met69Ile-Gly238Ser enzyme were 0.03 and 0.15 microM, respectively. Relative Vmax values indicate that the Met69Ile-Gly238Ser mutant of the OHIO-1 beta-lactamase possesses cephalosporinase activity similar to that of the Gly238Ser mutant but diminished penicillinase activity. In an Escherichia coli DH5alpha strain that possesses a Met69Ile beta-lactamase of the OHIO-1 family, the added Gly238Ser mutation resulted in a phenotype with qualities that confer resistance to expanded-spectrum cephalosporins and, to a lesser extent, beta-lactamase inhibitors.


2021 ◽  
Vol 5 (2) ◽  
pp. 1198-1207
Author(s):  
Kien Chi Le ◽  
Cuong Quoc Vo ◽  
Xuan Thanh Tran ◽  
Hung Manh Dang ◽  
Huyen Ngoc My Nguyen ◽  
...  

The global prevalence of antimicrobial resistance and Extended-Spectrum and AmpC Beta- Lactamases is continuously widespread among Escherichia coli during recent years, especially in Viet Nam. In Viet Nam, there have been researches on ESBL and AmpC-carrying E. coli inhabiting animal and human. However, studies of antimicrobial resistance in E. coli residing in pets, especially dogs are unavailable. The aim of the study was to investigate the antimicrobial sensitivity testing (AST), the resistance to 3rd cephalosporin and penicillin, also to assess the molecular detection of ESBL and Amp-C-beta -lactamase in E. coli isolates inhabiting the digestive tract of dogs at kennels Dak Lak. By using double disk synergy test (DDST), and ceftazidime-imipenem antagonism test (CIAT) to detect phenotypic characteristic of E. coli strains producing extended-spectrum beta- lactamases (ESBLs) and plasmid-mediated Amp-C-beta -lactamase, and by using multiplex polymerase chain reaction (multiplex PCR) to confirm the presence of ESBL genes (class A): blaCTX-M(1;2;8;9;25), bla TEM, bla SHV , bla OXA and genes encoding AmpC-type beta lactamase (class C): bla MOX-1;2 , bla CMY- (1;2-7;8-11) , blaLAT-(1;4) ,bla DHA-(1;2), bla ACC, bla FOX-(1-5B) ,bla MIR-1 ,bla ACT-1. From of three hundred twelve bacteial strains isolated from sixty-four rectal swabs two hundred sixty-nine E. Coli, isolates accounting for 86%, were identified and isolated, forty-four (16%) and twelve (4%) E. coli isolates encoding with ESBL and Amp-C-beta -lactamases. From molecular diagnosis with regard to phenotype, production of ESBL was shown in thirty-nine (15%) E. coli isolates and Amp-C enzymes in eight (3%) E. coli isolates. The high percentage of E. coli exhibiting antibiotic resistance revealed the accelerated overuse of antibiotics. Result of this study will contribute to the monitoring of epidemiologic resistance.


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