FIG 4.

Salmonella populations recovered from the tissues of infected calves. Calves were orally challenged with an inoculum containing 11 S. enterica serovars in approximately equal proportions. The contributions of each serovar to the population in each tissue (abundance) are represented by color-coded bars, and the number of serovars present in each pool (richness) is indicated by dots. The composition of the inoculum as determined by viable counts (expected) was not significantly different from that determined by sequencing and quantification of diagnostic SNPs (observed). In the distal ileum, MLNs, and CLNs of all 3 calves, S. Typhimurium was the predominant serovar, and these tissues had less richness than the PLNs. Salmonella serovars Typhimurium and Dublin were most abundant in the livers of all the animals. The PLNs (prescapular, prefemoral, and popliteal lymph nodes) had richness scores of at least 10, indicating that all the serovars could reach and survive within these tissues by 48 h postinfection. Salmonella serovars Typhimurium and Anatum were most abundant across all the PLNs.