[Antibiotic resistance in Salmonella enterica: an increasing problem].
OBJECTIVE
To determine the evolution of the frequencies of Salmonella enterica serotypes and their resistance to antimicrobial agents.


METHODS
A retrospective study of all S. enterica strains isolated from stool samples in the Hospital Clinico Universitario of Zaragoza over the period 1990-1994.


RESULTS
Enteritidis was the most frequently isolated serotype (62.9%), although it showed a progressive decrease (from 76.2% in 1990 to 39.8% in 1994). Typhimurium was the serotype showing the highest resistance levels, 37.1% of its isolates being resistant to ampicillin, streptomycin, chloramphenicol and tetracyclin. There was a distinct increase in the frequency of multiresistant strains, from 9.7% in 1990 to 22.9% in 1994. Of 88 such strains, 78.4% corresponded to serogroup B, whereas only 4.5% to serogroup D. Of the antimicrobial agents traditionally considered elective, only cotrimoxazole maintained acceptable resistance levels (4.4%). Resistance to fluoroquinolones or 3rd-generation cephalosporines was not detected.


CONCLUSIONS
The increasing frequency of Typhimurium, a highly resistant serotype, restrains the elective antimicrobial agents to cotrimoxazole in children and fluoroquinolones in adults. 3rd-generation cefalosporines may be a good alternative in case of therapeutic failure.
Galán
J C
JC
Servicio de Microbiología, Hospital Clínico Universitario Lozano Blesa, Zaragoza.
Varea
M
M
Castillo
F J
FJ
Clavel
A
A
Gómez-Lus
R
R
D004352:Drug Resistance, Microbial; D006801:Humans; D012189:Retrospective Studies; D012475:Salmonella / Q000145:classification / Q000187:drug effects*; D012477:Salmonella enteritidis / Q000187:drug effects; D012486:Salmonella typhimurium / Q000187:drug effects