New Variant of Multidrug-Resistant Salmonella enterica Serovar Typhimurium Associated with Invasive Disease in Immunocompromised Patients in Vietnam
Mather AE., Phuong TLT., Gao Y., Clare S., Mukhopadhyay S., Goulding DA., Hoang NTD., Tuyen HT., Lan NPH., Thompson CN., Trang NHT., Carrique-Mas J., Tue NT., Campbell JI., Rabaa MA., Thanh DP., Harcourt K., Hoa NT., Trung NV., Schultsz C., Perron GG., Coia JE., Brown DJ., Okoro C., Parkhill J., Thomson NR., Chau NVV., Thwaites GE., Maskell DJ., Dougan G., Kenney LJ., Baker S.
Salmonella Typhimurium is a major diarrheal pathogen and associated with invasive nontyphoid Salmonella (iNTS) disease in vulnerable populations. We present the first characterization of iNTS organisms in Southeast Asia and describe a different evolutionary trajectory from that of organisms causing iNTS in sub-Saharan Africa. In Vietnam, the globally distributed monophasic variant of Salmonella Typhimurium, the serovar I:4,,12:i:− ST34 clone, has reacquired a phase 2 flagellum and gained a multidrug-resistant plasmid to become associated with iNTS disease in HIV-infected patients. We document distinct communities of S . Typhimurium and I:4,,12:i:− in animals and humans in Vietnam, despite the greater mixing of these host populations here. These data highlight the importance of whole-genome sequencing surveillance in a One Health context in understanding the evolution and spread of resistant bacterial infections.