spp. Isolated from Tonsils of Wild Deer and Boars: Genomic Characterization.

is a major human and animal foodborne pathogen. However, data from environmental reservoirs remain scarce. Here, we used whole-genome sequencing to characterize species isolates recovered over 1 year from wild animals in their natural habitats in Spain. Three different spp. ( [ = 19], subsp. [ = 4], and [ = 3]) were detected in 23 animal tonsils (9 deer, 14 wild boars) and 2 feeding troughs. No species was detected in feces. was detected in tonsils of 44.4% (8 out of 18) of deer and 40.7% (11 out of 27) of wild boars. isolates belonged to 3 different core genome multilocus sequence typing (cgMLST) types (CTs) of 3 distinct sublineages (SL1, SL387, and SL155) from lineages I and II. While cgMLST type L1-SL1-ST1-CT5279 (IVb; clonal complex 1 [CC1]) occurred only in one animal, types L1-SL387-ST388-CT5239 (IVb; CC388) and L2-SL155-ST155-CT1170 (IIa; CC155) were retrieved from multiple animals. In addition, L1-SL387-ST388-CT5239 (IVb; CC388) isolates were collected 1 year apart, revealing their long-term occurrence within the animal population and/or environmental reservoir. The presence of identical strains in deer and wild boars suggests contamination from a common food or environmental source, although interhost transmission cannot be excluded. Pathogenicity islands LIPI-1, LIPI-3, and LIPI-4 were present in 100%, 5%, and 79% of the isolates, respectively, and all lineage II isolates ( = 3) carried SSI-1 stress islands. This study highlights the need for monitoring environmental contamination and the importance of tonsils as a possible intrahost reservoir. is a foodborne bacterial pathogen responsible for listeriosis. Whole-genome sequencing has been extensively used in public health and food industries to characterize circulating isolates, but genomic data on isolates occurring in natural environments and wild animals are still scarce. Here, we show that wild animals carry pathogenic and that the same genotypes can be found at different time points in different host species. This work highlights the need of species monitoring of environmental contamination and the importance of tonsils as a possible intrahost reservoir.