Genomic diversity of Listeria monocytogenes isolates from seafood, horticulture and factory environments in New Zealand

Listeria monocytogenes is a foodborne human pathogen that causes systemic infection, fetal-placental infection in pregnant women causing abortion and stillbirth meningoencephalitis elderly immunocompromised individuals. This study aimed to analyse L. from different sources New Zealand (NZ) compare them with international strains. We used pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) whole-genome single nucleotide polymorphisms (SNP) the population structure of NZ isolates their relationship The formed unique clusters PFGE, MLST SNP comparisons compared for which data were available. PFGE identified 31 AscI 29 ApaI patterns indistinguishable pulsotypes being present seafood, horticultural products environmental samples. Apart Asc0002:Apa0002 pulsotype was distributed across sources, other site or factory associated. Whole-genome analysis 200 randomly selected revealed lineage II dominated populations. comparison accounted 89% (177 200) total population, while representation 45.3% (1674 3473). Rarefaction showed type richness greater trend, however, it should be noted predominantly came horticulture respective processing environments factories, unlike where there good mixture clinical, food isolates.