Clinical Infectious Diseases 2021

Characteristics of Salmonella recovered from stools of children enrolled in the Global Enteric Multicenter Study.

Kasumba IN, Pulford CV, Perez-Sepulveda BM, Sen S, Sayed N, Permala-Booth J, Livio S, Heavens D, Low R, Hall N, Roose A, Powell H, Farag T, Panchalingham S, Berkeley L, Nasrin D, Blackwelder WC, Wu Y, Tamboura B, Sanogo D, Onwuchekwa U, Sow SO, Ochieng JB, Omore R, Oundo JO, Breiman RF, Mintz ED, O'Reilly CE, Antonio M, Saha D, Hossain MJ, Mandomando I, Bassat Q, Alonso PL, Ramamurthy T, Sur D, Qureshi S, Zaidi AKM, Hossain A, Faruque ASG, Nataro JP, Kotloff KL, Levine MM, Hinton JCD, Tennant SM
25.01.2021
The Global Enteric Multicenter Study (GEMS) determined the etiologic agents of moderate-to-severe diarrhea (MSD) in children under 5 years old in Africa and Asia. Here, we describe the prevalence and antimicrobial susceptibility of non-typhoidal Salmonella (NTS) serovars in GEMS and examine the phylogenetics of Salmonella Typhimurium ST313 isolates. Salmonella isolated from children with MSD or diarrhea-free controls were identified by classical clinical microbiology and serotyped using antisera and/or whole genome sequence data. We evaluated antimicrobial susceptibility using the Kirby-Bauer disk diffusion method. Salmonella Typhimurium sequence types were determined using multi-locus sequence typing and whole genome sequencing was performed to assess the phylogeny of ST313. Out of 370 Salmonella-positive individuals, 190 (51.4%) were MSD cases and 180 (48.6%) were diarrhea-free controls. The most frequent Salmonella serovars identified were Salmonella Typhimurium, serogroup O:8 (C2-C3), serogroup O:6,7 (C1), Salmonella Paratyphi B Java and serogroup O:4 (B). The prevalence of NTS was low but similar across sites, regardless of age, and was similar amongst both cases and controls except in Kenya, where Salmonella Typhimurium was more commonly associated with cases than controls. Phylogenetic analysis showed that these Salmonella Typhimurium isolates, all ST313, were highly genetically related to isolates from controls. Generally, Salmonella isolates from Asia were resistant to ciprofloxacin and ceftriaxone but African isolates were susceptible to these antibiotics. Our data confirms that NTS is prevalent, albeit at low levels, in Africa and South Asia. Our findings provide further evidence that multi-drug resistant Salmonella Typhimurium ST313 can be carried asymptomatically by humans in sub-Saharan Africa. © The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America.