Open AccessTrends in Production of Extended-Spectrum β-Lactamases among Enterobacteria of Medical Interest: Report of the Second Italian Nationwide Survey
Author(s) -
Francesco Luzzaro,
Maria Lina Mezzatesta,
C. Mugnaioli,
Mariagrazia Perilli,
Stefania Stefani,
Gianfranco Amicosante,
Gian María Rossolini,
Antonio Toniolo
Publication year - 2006
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.44.5.1659-1664.2006
Subject(s) - proteus mirabilis , imipenem , amikacin , microbiology and biotechnology , piperacillin , klebsiella pneumoniae , providencia , gentamicin , biology , tazobactam , ciprofloxacin , medicine , antibiotics , escherichia coli , enterobacteriaceae , pseudomonas aeruginosa , antibiotic resistance , bacteria , biochemistry , genetics , gene
Results of a 2003 survey carried out in Italy to evaluate the prevalence of extended-spectrum β-lactamase (ESBL)-producing enterobacteria are presented. Eleven Italian Microbiology Laboratories investigated 9,076 consecutive nonreplicate isolates (inpatients, 6,850; outpatients, 2,226). ESBL screening was performed by MIC data analysis. Confirmation was obtained using the double-disk synergy test and the combination disk test based on CLSI methodology. ESBL determinants were investigated by colony blot hybridization and confirmed by sequencing. Results were compared to those of the 1999 Italian survey (8,015 isolates). The prevalence of ESBL producers was 7.4% among isolates from inpatients (in 1999, 6.3%) and 3.5% among outpatients (no data were available for 1999). Among hospitalized patients, the most prevalent ESBL-positive species wasEscherichia coli (Klebsiella pneumoniae in 1999).Proteus mirabilis was the most prevalent ESBL-positive species among outpatients. In both groups, most ESBL-positive pathogens were obtained from urinary tract infections. TEM-type ESBLs were the most prevalent enzymes (45.4%). Non-TEM, non-SHV determinants emerged: CTX-M-type inE. coli andK. pneumoniae , and PER-type inP. mirabilis ,Providencia spp., andE. coli . With the exception of 3/163P. mirabilis isolates and 1/44Providencia stuartii isolate (all of which were intermediate for imipenem), carbapenems were active against all ESBL-positive enterobacteria. Susceptibility to other drugs was as follows: 84.7% for amikacin, 84.4% for piperacillin-tazobactam, 48.0% for gentamicin, and 32.8% for ciprofloxacin. Carbapenems appear to be the drug of choice. Amikacin and β-lactam/β-lactamase inhibitor combinations represent an alternative in non-life-threatening infections. The appearance of ESBL-positive enterobacteria in the community makes it mandatory that family physicians learn how to treat these pathogens.