TY - JOUR
T1 - Antimicrobial susceptibility of clinical isolates of Enterobacteriaceae producing complex β-lactamase patterns including extended-spectrum enzymes
AU - Segatore, Bernardetta
AU - Setacci, Domenico
AU - Perilli, Mariagrazia
AU - Franchino, Luigi
AU - Franceschini, Nicola
AU - Agnifili, Alessio
AU - Rossolini, Gian Maria
AU - Amicosante, Gianfranco
PY - 2004/5
Y1 - 2004/5
N2 - The antimicrobial susceptibility of 103 clinical isolates of Enterobacteriaceae to 11 antibiotics, was investigated, using a conventional inoculum size (5×105 CFU) and a higher inoculum size (5×108 CFU). All the isolates produced complex β-lactamase patterns, including an extended-spectrum β-lactamase (ESBL) of the TEM- or SHV-type plus other enzymes (a TEM-type or an SHV-type non-ESBL and/or a class C enzyme). The following repertoire of ESBLs was produced by the isolates: TEM-15, TEM-19, TEM-26, TEM-52, TEM-72, TEM-87, TEM-92, SHV-2a, SHV-5 and SHV-12, as assessed by sequencing. Production of the other enzymes was showed by analytical isoelectric focusing. Overall, meropenem was the most active agent and less influenced by inoculum size, while other β-lactams showed a lower activity and a significant inoculum size effect. In conclusion, from its in vitro performance, meropenem could be considered as the last resource drug against strains producing complex β-lactamase patterns including an ESBL.
AB - The antimicrobial susceptibility of 103 clinical isolates of Enterobacteriaceae to 11 antibiotics, was investigated, using a conventional inoculum size (5×105 CFU) and a higher inoculum size (5×108 CFU). All the isolates produced complex β-lactamase patterns, including an extended-spectrum β-lactamase (ESBL) of the TEM- or SHV-type plus other enzymes (a TEM-type or an SHV-type non-ESBL and/or a class C enzyme). The following repertoire of ESBLs was produced by the isolates: TEM-15, TEM-19, TEM-26, TEM-52, TEM-72, TEM-87, TEM-92, SHV-2a, SHV-5 and SHV-12, as assessed by sequencing. Production of the other enzymes was showed by analytical isoelectric focusing. Overall, meropenem was the most active agent and less influenced by inoculum size, while other β-lactams showed a lower activity and a significant inoculum size effect. In conclusion, from its in vitro performance, meropenem could be considered as the last resource drug against strains producing complex β-lactamase patterns including an ESBL.
KW - β-Lactam antibiotics
KW - ESBL
KW - Resistance
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U2 - 10.1016/j.ijantimicag.2003.10.011
DO - 10.1016/j.ijantimicag.2003.10.011
M3 - Article
C2 - 15120727
AN - SCOPUS:2342646185
VL - 23
SP - 480
EP - 486
JO - International Journal of Antimicrobial Agents
JF - International Journal of Antimicrobial Agents
SN - 0924-8579
IS - 5
ER -