TY - JOUR
T1 - Dynamics of a nosocomial outbreak of multidrug-resistant Pseudomonas aeruginosa producing the PER-1 extended-spectrum β-lactamase
AU - Luzzaro, F.
AU - Mantengoli, E.
AU - Perilli, M.
AU - Lombardi, G.
AU - Orlandi, V.
AU - Orsatti, A.
AU - Amicosante, G.
AU - Rossolini, G. M.
AU - Toniolo, A.
PY - 2001
Y1 - 2001
N2 - From November 1998 to August 1999, a large outbreak occurred in the general intensive care unit of the Ospedale di Circolo in Varese (Italy), caused by Pseudomonas aeruginosa producing the PER-1 extended-spectrum β-lactamase. A total of 108 clinical isolates of P. aeruginosa resistant to broad-spectrum cephalosporins were recovered from 18 patients. Epidemic isolates were characterized by synergy between clavulanic acid and ceftazidime, cefepime, and aztreonam. Isoelectric focusing of crude bacterial extracts detected two nitrocefin-positive bands with pI values of 8.0 and 5.3. PCR amplification and characterization of the amplicons by restriction analysis and direct sequencing indicated that the epidemic isolates carried a blaPER-1 determinant. The outbreak was of clonal origin as shown by pulsed-field gel electrophoresis analysis. This technique also indicated that the epidemic strain was not related to three other PER-1-positive isolates obtained at the same hospital in 1997. Typing by enterobacterial repetitive intergenic consensus-PCR showed that minor genetic variations occurred during the outbreak. The epidemic strain was characterized by a multiple-drug-resistance phenotype that remained unchanged over the outbreak, including extended-spectrum cephalosporins, monobactams, aminoglycosides, and fluoroquinolones. Isolation of infected patients and appropriate carbapenem therapy were successful in ending the outbreak. Our report indicates that the blaPER-1 resistance determinant may become an emerging therapeutic problem in Europe.
AB - From November 1998 to August 1999, a large outbreak occurred in the general intensive care unit of the Ospedale di Circolo in Varese (Italy), caused by Pseudomonas aeruginosa producing the PER-1 extended-spectrum β-lactamase. A total of 108 clinical isolates of P. aeruginosa resistant to broad-spectrum cephalosporins were recovered from 18 patients. Epidemic isolates were characterized by synergy between clavulanic acid and ceftazidime, cefepime, and aztreonam. Isoelectric focusing of crude bacterial extracts detected two nitrocefin-positive bands with pI values of 8.0 and 5.3. PCR amplification and characterization of the amplicons by restriction analysis and direct sequencing indicated that the epidemic isolates carried a blaPER-1 determinant. The outbreak was of clonal origin as shown by pulsed-field gel electrophoresis analysis. This technique also indicated that the epidemic strain was not related to three other PER-1-positive isolates obtained at the same hospital in 1997. Typing by enterobacterial repetitive intergenic consensus-PCR showed that minor genetic variations occurred during the outbreak. The epidemic strain was characterized by a multiple-drug-resistance phenotype that remained unchanged over the outbreak, including extended-spectrum cephalosporins, monobactams, aminoglycosides, and fluoroquinolones. Isolation of infected patients and appropriate carbapenem therapy were successful in ending the outbreak. Our report indicates that the blaPER-1 resistance determinant may become an emerging therapeutic problem in Europe.
UR - http://www.scopus.com/inward/record.url?scp=0035015071&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035015071&partnerID=8YFLogxK
U2 - 10.1128/JCM.39.5.1865-1870.2001
DO - 10.1128/JCM.39.5.1865-1870.2001
M3 - Article
C2 - 11326005
AN - SCOPUS:0035015071
VL - 39
SP - 1865
EP - 1870
JO - Journal of Clinical Microbiology
JF - Journal of Clinical Microbiology
SN - 0095-1137
IS - 5
ER -