Antimicrobial resistance in Salmonella enteritidis from foods involved in human salmonellosis outbreaks in southern Brazil.

The antimicrobial resistance of Salmonella Enteritidis (n = 79) isolated from foods involved in human salmonellosis outbreaks in Southern Brazil during the period of 2001 to 2002 was analysed. The isolates were individually tested using the disc diffusion method against 10 antimicrobial agents. Most isolates were susceptible to all drugs tested. No S. Enteritidis isolates were resistant to sulfamethoxazole/trimethoprim or sulfazotrim and only one was resistant to chloramphenicol. The predominant resistance observed was to nalidixic acid (21.5%), gentamicin (12.7%), and streptomycin (11.4%), while intermediate resistance was observed most often for kanamycin (29.1%), neomycin (17.7%), and streptomycin (13.9%). Resistance was verified in 30 isolates (30.97%) grouped in 14 different patterns. Resistance to more than one agent was verified in 13 (16.46%) of the isolates. Two isolates were resistant to four drugs and only one strain presented resistance to three antibiotics.