High genetic similarity between non-typhoidal Salmonella isolated from paired blood and stool samples of children in the Democratic Republic of the Congo

摘要

Non-typhoidal Salmonella (NTS) is an important cause of bloodstream infections in sub-Saharan Africa, but little is known about its reservoir and transmission. We assessed the possibility of a human reservoir by culturing stool samples from children with NTS found in their blood. Next, we compared the obtained blood and stool NTS isolates for genetic similarity. We found that a high proportion of children with NTS in their blood also had NTS in their stool (35.1%) when compared to a control group of children without suspicion of bloodstream infection (2.1%). We observed that Salmonella Typhimurium and Salmonella Enteritidis were the main serotypes isolated from blood and stool, and that their proportions were similar within the different populations. We found that 94.3% of the paired NTS blood and stool isolates (or 27.4% of children with NTS in their blood and a stool culture done) were genetically similar to each other. This observation adds to the evidence of a potential human reservoir for NTS.