TY - JOUR
T1 - Performance in detection and reporting β-lactam resistance phenotypes in Enterobacteriaceae
T2 - a nationwide proficiency study in Italian laboratories
AU - Luzzaro, Francesco
AU - Gesu, Giovanni
AU - Endimiani, Andrea
AU - Ortisi, Giuseppe
AU - Malandrin, Sergio
AU - Pagani, Laura
AU - Rossolini, Gian Maria
PY - 2006/8
Y1 - 2006/8
N2 - We evaluated the ability of 60 Italian clinical microbiology laboratories in detecting and reporting β-lactam resistance phenotypes in Enterobacteriaceae. Laboratories received 5 well-characterized isolates producing extended-spectrum β-lactamases (ESBLs), 2 hyperproducers of chromosomal enzymes, and 3 quality control strains. The performances in antimicrobial susceptibility testing (AST) were different depending on the species and type of ESBL produced. High rates of very major errors (up to 56%) were observed for ESBL producers when testing cephalosporins and aztreonam, especially in the case of CTX-M-1-producing Escherichia coli and TEM-52-producing Proteus mirabilis. Isolates hyperproducing chromosomal enzymes were erroneously reported as ESBL producers in approximately 20% of cases. Detection of ESBLs is still a problem for clinical microbiology laboratories. Overall, performances in AST appear to be better with Klebsiella spp. producing well-known enzymes (e.g., SHV type) than with strains producing emerging enzymes (e.g., CTX-M type) or organisms not well recognized as ESBL producers (e.g., P. mirabilis).
AB - We evaluated the ability of 60 Italian clinical microbiology laboratories in detecting and reporting β-lactam resistance phenotypes in Enterobacteriaceae. Laboratories received 5 well-characterized isolates producing extended-spectrum β-lactamases (ESBLs), 2 hyperproducers of chromosomal enzymes, and 3 quality control strains. The performances in antimicrobial susceptibility testing (AST) were different depending on the species and type of ESBL produced. High rates of very major errors (up to 56%) were observed for ESBL producers when testing cephalosporins and aztreonam, especially in the case of CTX-M-1-producing Escherichia coli and TEM-52-producing Proteus mirabilis. Isolates hyperproducing chromosomal enzymes were erroneously reported as ESBL producers in approximately 20% of cases. Detection of ESBLs is still a problem for clinical microbiology laboratories. Overall, performances in AST appear to be better with Klebsiella spp. producing well-known enzymes (e.g., SHV type) than with strains producing emerging enzymes (e.g., CTX-M type) or organisms not well recognized as ESBL producers (e.g., P. mirabilis).
KW - β-Lactamases
KW - Antimicrobial resistance
KW - AST
KW - Enterobacteria
KW - ESBL
UR - http://www.scopus.com/inward/record.url?scp=33746391403&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33746391403&partnerID=8YFLogxK
U2 - 10.1016/j.diagmicrobio.2006.01.017
DO - 10.1016/j.diagmicrobio.2006.01.017
M3 - Article
C2 - 16678993
AN - SCOPUS:33746391403
VL - 55
SP - 311
EP - 318
JO - Diagnostic Microbiology and Infectious Disease
JF - Diagnostic Microbiology and Infectious Disease
SN - 0732-8893
IS - 4
ER -