Molecular Typing of Listeria monocytogenes IVb Serogroup Isolated from Food and Food Production Environments in Poland

Abstract

Listeria monocytogenes is one of the most important foodborne pathogens that may be present in food and in food processing environments. In the present study, 91 L. monocytogenes isolates of serogroup IVb from raw meat, ready-to-eat food and food production environments in Poland were characterized by whole genome sequencing (WGS). The strains were also compared, using core genome multi-locus sequence typing (cgMLST) analysis, with 186 genomes of L. monocytogenes recovered worldwide from food, environments, and from humans with listeriosis. The L. monocytogenes examined belonged to three MLST clonal complexes: CC1 (10; 11.0% isolates), CC2 (70; 76.9%), and CC6 (11; 12.1%). CC1 comprised of two STs (ST1 and ST515) which could be divided into five cgMLST, CC2 covered two STs (ST2 and ST145) with a total of 20 cgMLST types, whereas CC6 consisted of only one ST (ST6) classified as one cgMLST. WGS sequences of the tested strains revealed that they had several pathogenic markers making them potentially hazardous for public health. Molecular comparison of L. monocytogenes strains tested in the present study with those isolated from food and human listeriosis showed a relationship between the isolates from Poland, but not from other countries.

Characterization and Genetic Diversity of Listeria monocytogenes Isolated from Cattle Abortions in Latvia, 2013–2018

“…Serogroup IVb was found to be more prevalent than IIa among wildlife animal samples in Spain [41]. Hypervirulent clones of IVb were present in food and food production environments, highlighting their importance associated with human invasive listeriosis cases [42]. In our dataset, CC1 in the context of abortion was not observed at all, and neurological manifestations of listeriosis in cattle in Latvia are rarely reported, only one case since 2013, and in that case, we identified L. monocytogenes ST1 (CC1) (unpublished data, BIOR).…”

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“…In this study, CC1, CC2, CC4, and CC6 made up 66.7% of lineage I isolates and were isolated from food, FPEs, and animals, as well as from human cases. This result is similar to that reported in Lachtara et al (2021) on the prevalence of CC1, CC2, and CC6 in food and FPE isolates in Poland. These CCs have previously been described as hypervirulent (Maury et al, 2016).…”

Evaluation of the Persistence and Characterization of Listeria monocytogenes in Foodservice Operations

“…In this study, L. monocytogenes serogroup IVb, CC2/ST2 was the isolates most frequently detected from drains (FSOpA and B). Similarly, the same molecular variant was predominant in an analysis performed in Poland in a study monitoring RTE foods, meat, and food environments [ 80 ]. It has also been reported that CC2 isolates were more salt-tolerant than isolates belonging to other CCs [ 81 ].…”