Emergence of Multidrug-Resistant<i>Salmonella enterica</i>SerotypeTyphimurium DT104 Infections in the United States

TLDR

Resistant Salmonella strains pose a global health problem, with DT104 a major cause of illness in Europe. The study aimed to characterize DT104 infections in the United States by analyzing data from local and state health departments and public laboratories collected between 1979 and 1996. Researchers phage‑typed isolates exhibiting the five‑drug resistance pattern and tracked its prevalence over time. DT104 prevalence rose from 0.6 % in 1979‑80 to 34 % in 1996, with 78 % of surveillance sites reporting it in 1994‑95 and most isolates being phage type DT104, establishing it as a widespread pathogen and highlighting the need for prudent antimicrobial use.

Abstract

Strains of salmonella that are resistant to antimicrobial agents have become a worldwide health problem. A distinct strain of Salmonella enterica serotype typhimurium, known as definitive type 104 (DT104), is resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline and has become a major cause of illness in humans and animals in Europe, especially the United Kingdom.To characterize typhimurium DT104 infections in the United States, we analyzed data collected by local and state health departments and public health laboratories between 1979 and 1996 in national surveys of the antimicrobial-drug resistance of salmonella. Selected typhimurium isolates with the five-drug pattern of resistance were phage typed.The prevalence of typhimurium isolates with the five-drug pattern of resistance increased from 0.6 percent in 1979-1980 to 34 percent in 1996. In 1994-1995, such isolates were identified in samples from 36 of the 46 surveillance sites (78 percent). Thirty-nine of 43 typhimurium isolates with the five-drug pattern of resistance identified in 1994-1995 and 1996 were phage type DT104 or a closely related phage type.Multidrug-resistant typhimurium DT104 has become a widespread pathogen in the United States. More prudent use of antimicrobial agents in farm animals and more effective disease prevention on farms are necessary to reduce the dissemination of multidrug-resistant typhimurium DT104 and to slow the emergence of resistance to additional agents in this and other strains of salmonella.