ß-lactamases produced by amoxicillin-clavulanate-resistant enterobacteria isolated in Buenos Aires, Argentina: a new blaTEM gene. / ß-lactamases produced by amoxicillin-clavulanate-resistant enterobacteria isolated in Buenos Aires, Argentina: a new blaTEM gene.
Rev. argent. microbiol
; 46(3): 210-7, 2014 Jul-Sep.
Article
em Es
| BINACIS
| ID: bin-133299
ABSTRACT
Resistance to ß-lactam/ß-lactamase inhibitors in enterobacteria is a growing problem that has not been intensively studied in Argentina. In the present work, 54/843 enterobacteria collected in a teaching hospital of Buenos Aires city were ampicillin-sulbactam-resistant isolates remaining susceptible to second- and third-generation cephalosporins. The enzymatic mechanisms present in the isolates, which were also amoxicillin-clavulanic acid (AMC)-resistant (18/54) were herein analyzed. Sequencing revealed two different variants of blaTEM-1, being blaTEM-1b the most frequently detected allelle (10 Escherichia coli, 3 Klebsiella pneumoniae, 2 Proteus mirabilis and 1 Raoultella terrigena) followed by blaTEM-1a (1 K. pneumoniae). Amoxicillin-clavulanate resistance seems to be mainly associated with TEM-1 overproduction (mostly in E. coli) or co-expressed with OXA-2-like and/or SHV ß-lactamases (K. pneumoniae and P. mirabilis). A new blaTEM variant (TEM-163) was described in an E. coli strain having an AMC MIC value of 16/8Ag/ml. TEM-163 contains Arg275Gln and His289Leu amino acid substitutions. On the basis of the high specific activity and low IC50 for clavulanic acid observed, the resistance pattern seems to be due to overproduction of the new variant of broad spectrum ß-lactamase rather than to an inhibitor-resistant TEM (IRT)-like behavior.
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Coleções:
06-national
/
AR
Base de dados:
BINACIS
Assunto principal:
Beta-Lactamases
/
Combinação Amoxicilina e Clavulanato de Potássio
/
Farmacorresistência Bacteriana
/
Enterobacteriaceae
/
Infecções por Enterobacteriaceae
País/Região como assunto:
America do sul
/
Argentina
Idioma:
Es
Revista:
Rev. argent. microbiol
Ano de publicação:
2014
Tipo de documento:
Article
País de publicação:
Argentina