Molecular diversity and antimicrobial susceptibility of Listeria monocytogenes isolates from invasive infections in Poland (1997–2013)

Abstract

The epidemiology of invasive listeriosis in humans appears to be weakly characterized in Poland, the sixth most populous member state of the European Union. We obtained antimicrobial susceptibility data, PCR-serogroups and genotypic profiles for 344 invasive isolates of Listeria monocytogenes, collected between 1997 and 2013 in Poland. All isolates were susceptible to the 10 tested antimicrobials, except one that was resistant to tetracycline and minocycline and harbored the tet(M), tet(A) and tet(C) genes. Overall, no increasing MIC values were observed during the study period. Four PCR-serogroups were observed: IVb (55.8%), IIa (34.3%), IIb (8.1%) and IIc (1.8%). We identified clonal complexes (CCs) and epidemic clones (ECs) previously involved in outbreaks worldwide, with the most prevalent CCs/ECs being: CC6/ECII (32.6%), CC1/ECI (17.2%), CC8/ECV (6.1%) and CC2/ECIV (5.5%). The present study is the first extensive analysis of Polish L. monocytogenes isolates from invasive infections.

Genomic Characterization of Listeria monocytogenes Isolated From Ready-to-Eat Meat and Meat Processing Environments in Poland

“…This confirms the previous findings that meat products may be a potential source of L. monocytogenes associated with human infections (Buchanan et al, 2017). Furthermore, the present analysis also showed that isolates belonging to five cgMLST types found in food (LI-SL1-ST1-CT1385, LI-SL1-ST1-CT322, LI-SL2-ST2-CT4382, LI-SL6-ST6-CT461, LI-SL6-ST6-CT443) were previously identified among human listeriosis isolates in Poland (Kuch et al, 2018) and other European countries (Denmark and France) (Moura et al, 2016(Moura et al, , 2017. The close genetic distance between isolates within each cgMLST suggests a possible epidemiological link.…”

“…cgMLST profiles were grouped into cgMLST types (CTs) and sublineages (SLs), using the cut-offs of 7 and 150 allelic mismatches, respectively, as previously described (Moura et al, 2016). The cgMLST profiles obtained in this study were also compared with those from 55 PCR-serogroup IVb and 8 PCR-serogroup IIb publicly available genome sequences of L. monocytogenes isolated from patients in Poland (Kuch et al, 2018). All calculations were made with the method described above.…”

“…Gray shadows highlight the five groups of isolates with the 99.6% similarity, isolated from both humans and food. Clinical isolates were described by Kuch et al (2018). Rings info, from the outer side: sublineages, source of isolates, number of isolates, the scale.…”

Source tracking on a dairy farm reveals a high occurrence of subclinical mastitis due to hypervirulentListeria monocytogenesclonal complexes

“…Listeria monocytogenes faecal shedding in cattle was not confirmed, but this might be a result of the limited number of faecal samples collected on a single date. Although CC11 is not one of the most prevalent CCs in human (Maury et al ; Kuch et al ) and animal (Dreyer et al ; Steckler et al ) clinical isolates, it has been associated with ruminant neurolisteriosis cases (Dreyer et al ).…”

Population structure-guided profiling of antibiotic resistance patterns in clinical Listeria monocytogenes isolates from Germany identifies pbpB3 alleles associated with low levels of cephalosporin resistance

“…As previously reported, resistance to the clinically used antibiotics is rare in clinical isolates of L. monocytogenes [21][22][23], however, recent studies report increasing numbers of antibiotic-resistant environmental isolates, including isolates from animals, food and food-processing plants [24][25][26]. This observation is alarming since there is evidence that the increase of minimal inhibitory concentrations (MIC) observed in environmental strains also manifested in clinical strains later on [27].…”