Complete Genome Sequences of Three Clinical Listeria monocytogenes Sequence Type 8 Strains from Recent German Listeriosis Outbreaks

Abstract

We report here the closed genome sequences of three clinical Listeria monocytogenes strains of multilocus sequence typing (MLST) sequence type 8 (ST8). These strains are representatives of three separate listeriosis outbreak clusters (Alpha1, Pi4, and Sigma1) that affected Germany between 2012 and 2020.

Genetic Diversity and Relationships of Listeria monocytogenes Serogroup IIa Isolated in Poland

“…The remaining seven strains, mainly recovered from RTE food, were grouped into three CCs, with single isolates in each ( Figure 1 ). L. monocytogenes of the CCs identified in the present study were also previously detected among 100 strains of IIa serogroup recovered from food but were also often isolated from humans with listeriosis [ 12 , 14 , 18 , 44 , 45 , 46 , 47 ].…”

“…The remaining seven strains, mainly recovered from RTE food, were grouped into three CCs, with single isolates in each (Figure 1). L. monocytogenes of the CCs identified in the present study were also previously detected among 100 strains of IIa serogroup recovered from food but were also often isolated from humans with listeriosis [12,14,18,[44][45][46][47]. Further analysis of WGS sequences revealed that all 100 current isolates were classified into eight sequence types, with the most prevalent ST155 (33; 33.0%), ST121 (30; 30.0%), and ST8 (28; 28.0%) (Figure 2).…”

“…Only two CC8 isolates of cgMLST types CT750 and CT9837, both of food production environments origin, were positive for the Tn6188_qac ( ermC ) transposon involved in QAC and other various disinfectants resistance widely used in food production ( Table 2 ) [ 68 , 71 ]. Isolates belonging to CC8 were also previously identified in food and in humans suffering from listeriosis [ 18 , 26 , 45 , 46 , 47 , 83 ]. However, there are also studies in which none of the L. monocytogenes classified to CC8 was positive for the Tn6188_qac ( ermC ) marker [ 49 , 80 ].…”

Large Multicountry Outbreak of Invasive Listeriosis by a Listeria monocytogenes ST394 Clone Linked to Smoked Rainbow Trout, 2020 to 2021

“…The Ny9 outbreak was caused by a ST394 clone. Genetic and phenotypic analysis demonstrated that this clone possessed a very similar virulence potential like the Sigma1 outbreak strain ( 22 , 46 ), which was one of the closest relatives in our strain collection. ST394 strains have not been described so far in the context of large outbreak clusters.…”

High density genomic surveillance and risk profiling of clinical Listeria monocytogenes subtypes in Germany, 2018-2021

“…This selection included strain 18-04540 from the large Epsilon1a outbreak (18) as a representative for ST6 with average MFL/NL risk (Fig. 3D), strain 21-03201 from the Alpha10 cluster representing hypervirulent ST1, strain 19-05816 from the Pi4 cluster (40) for hypovirulent ST8, strain 19-06323 (Chi1a cluster) as a hypovirulent ST14 isolate, the sporadic 21-04322 strain representing hypovirulent ST29 and the Omikron1 strain 17-01049 as a member of hypovirulent ST155.…”