Prevalence, antimicrobial resistance, and extended-spectrum beta-lactamases characterization of Salmonella isolates in Apulia, southern Italy (2001-2005).
The prevalence, antimicrobial susceptibility, and production of extended-spectrum beta-lactamases (ESBLs) of Salmonella collected from several hospitals in Apulia (southern Italy) were evaluated. The most common Salmonella isolates were Salmonella enterica serovar Typhimurium (44.6%), S. enterica serovar Enteritidis (33.4 %), S. enterica serovar Infantis (3.2 %), S. enterica serovar Typhi (1.5%), and S. enterica serovar Bovismorbificans (1.5%). The other serovars accounted for less than 1% each. Our data show a high resistance to ampicillin, tetracycline, and chloramphenicol. The isolates were pansensitive (53.5%), resistant to one antimicrobial agent (10.5%), resistant to two antimicrobial agents (22.1%), resistant to three antimicrobial agents (10.8%), and to four antimicrobial agents (2.7%). Resistance to more than four antibiotics was observed in 0.5% of strains. The presence of ESBL was found in only one strain of S. enterica serovar Bovismorbificans. The CTX-M-1 type-producing strain was identified by isoelectric focusing and molecular analysis. Results were consistent with the presence of a pI 8.6 ESBL active on cefotaxime, ceftazidime, cefepime, and aztreonam. Mating experiments showed that the CTX-M-1 determinant was transferable. To the best of our knowledge, this is the first report of CTX-M-1 type ESBL in Salmonella serovar Bovismorbificans.
Monno
Rosa
R
Department of Internal Medicine and Public Health, University of Bari, I 70124 Bari, Italy. r.monno@igiene-seconda.uniba.it
Rizzo
Caterina
C
De Vito
Danila
D
Nucleo
Elisabetta
E
Migliavacca
Roberta
R
Pagani
Laura
L
Rizzo
Giovanni
G
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D006761:Hospitals; D007558:Italy / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D012475:Salmonella / Q000201:enzymology*; D001618:beta-Lactamases / Q000235:genetics*
D000900:Anti-Bacterial Agents; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases