RESUMEN
Salmonella strains isolated from 1,138 samples representing 28,199 biological materials (stool, urine, blood and other fluids), collected between January 1985 and January 1999 at a reference University Hospital in Ribeiräo Preto, Säo Paulo, Brazil, were studied. The most frequently detected serotypes were Salmonella enterica subspecies enterica serotype4,5,12:i:- (S. I 4,5,12:i:) (21.2 percent), S. agona (15.8 percent) and S. enteritidis (11.3 percent). A changing pattern of Salmonella serotypes was observed between 1985-1999. S. agona, which represented 27 percent of Salmonella serotypes isolated from 1985-1989, declined to 4 percent during the period from 1995 to 1999. S. enteritidis isolation remained below 1 percent until 1989; rose to 5.9 percent between 1990 and 1994, and increased to 32.3 percent between 1995-1999. S. I 4,5,12:i:-; S. Enteritidis; S. Typhimurium; S. dublin and S. infantis, showed low to moderate resistance profiles to most antimicrobial drugs. Nalidixic acid and tetracycline were the most and the least effective drugs, respectively, in the disk diffusion tests. We encountered changes in salmonellosis epidemiology in this geographical region