|Tollefson, L - FDA, CVM|
Submitted to: American Association of Swine Practitioners Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 4, 1997
Publication Date: N/A
Technical Abstract: Salmonella typhimurium definitive phage type (DT) 104 was first identified in humans in England and Wales in 1984. This strain has a unique antimicrobial resistance pattern (R-type) with multiple resistance observed for ampicillin (A), chloramphenicol (C), streptomycin (S), sulfonamides (Su), and tetracycline (T) (ACSSuT). The number of isolations in the U.K. from humans rose slowly from 1984 to 1990 then more rapidly so that by 1993, DT104 with R-type ACSSuT accounted for over 80% of the isolations. In 1995, R-type ACSSuT DT104 accounted for over 87% of S. typhimurium isolates recovered from humans with 26.4% and 6.2% of these isolates having additional resistance to trimethoprim and ciprofloxacin, respectively. In the animal population in the U.K., DT104 was first recovered in 1989 from cattle. Since that time isolations have continued to rise and now account for the majority of S. typhimurium isolates. Recovery has also been documented from sheep, pigs, poultry, goats, rabbits, dogs, seabirds, rodents, porpoises, cats, horses, and animal feed. Contact with ill farm animals, particularly cattle, is implicated as a primary factor for transmission. Long-term carriage has also been observed in all species, particularly in cats and cattle. Illness associated with DT104 from humans and animals has now reached epidemic proportions in the U.K. This paper discusses the history, characteristics, and status of S. typhimurium DT104 in the U.S.