AUTHOR=Amarasekara Nirosha Ruwani , Swamy Amrita Subramanya , Paudel Sumit Kumar , Jiang Wentao , Li KaWang , Shen Cangliang , Zhang Yifan 

TITLE=Hypervirulent clonal complex (CC) of Listeria monocytogenes in fresh produce from urban communities

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1307610

DOI=10.3389/fmicb.2024.1307610

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>This study aimed to determine the prevalence and virulome of <italic>Listeria</italic> in fresh produce distributed in urban communities.</p></sec><sec><title>Methods</title><p>A total of 432 fresh produce samples were collected from farmer’s markets in Michigan and West Virginia, USA, resulting in 109 pooled samples. <italic>Listeria</italic> spp. were isolated and <italic>L. monocytogenes</italic> was subjected to genoserogrouping by PCR and genotyping by pulsed-field gel electrophoresis (PFGE). Multi-locus sequence typing (MLST) and core-genome multi-locus sequence typing (cgMLST) were conducted for clonal identification.</p></sec><sec><title>Results</title><p>Forty-eight of 109 samples (44.0%) were contaminated with <italic>Listeria</italic> spp. <italic>L. monocytogenes</italic> serotype 1/2a and 4b were recovered from radishes, potatoes, and romaine lettuce. Four clonal complexes (CC) were identified and included hypervirulent CC1 (ST1) and CC4 (ST219) of lineage I as well as CC7 (ST7) and CC11 (ST451) of lineage II. Clones CC4 and CC7 were present in the same romaine lettuce sample. CC1 carried <italic>Listeria</italic> pathogenicity island LIPI-1 and LIPI-3 whereas CC4 contained LIPI-1, LIPI-3, and LIPI-4. CC7 and CC11 had LIPI-1 only.</p></sec><sec><title>Discussion</title><p>Due to previous implication in outbreaks, <italic>L. monocytogenes</italic> hypervirulent clones in fresh produce pose a public health concern in urban communities.</p></sec>