Multidrug-resistant Salmonella Typhimurium DT104 in poultry

Salmonella Typhimurium isolates from feed ingredients or poultry sources is olated during 1995 to 1997 from different geographical locations within Min nesota were examined for the presence of Salmonella Typhimurium definitive type 104 (DT104). Antibiotic susceptibility studies indicated that 15 of 50 isolates of Salmonella Typhimurium had an antibiotic resistance pattern (a mpicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) t hat is usually observed with multi-drug-resistant Salmonella Typhimurium DT 104. Of the 15 isolates showing the antibiotic resistance pattern, 8 isolat es were phage type 104, 3 isolates were typed as phage type 104 complex, an d the remaining 4 isolates belonged to phage types 193, 81, and 126, DT104 was recovered from both feed ingredients and poultry samples. Of the seven feed ingredient-associated Salmonella Typhimurium isolates, four were DT104 , whereas only 7 of 43 poultry-associated Salmonella Typhimurium isolates w ere DT104. A repetitive sequence-based polymerase chain reaction (rep-PCR) of 50 isolates of Salmonella Typhimurium representing 13 phage types identi fied seven distinct fingerprint profiles. No correlation between phage type and rep-PCR type was noticed. Eleven Salmonella Typhimurium isolates belon ging to DT104 and its complex were grouped into two closely related rep-PCR types.