Examination of food chain-derived Listeria monocytogenes strains of different serotypes reveals considerable diversity in inlA genotypes, mutability, and adaptation to cold temperatures
Jovana Kovacevic , Carolina Arguedas-Villa , Anna Woźniak-Biel , Taurai Tasara , Kevin J. Allen
AbstractListeria monocytogenes strains belonging to serotypes 1/2a and 4b are frequently linked to listeriosis. While inlA mutations leading to premature stop codons (PMSCs) and attenuated virulence are common in 1/2a, they are rare in serotype 4b. We observed PMSCs in 35% of L. monocytogenes isolates (n=54) recovered from the British Columbia food supply, including serotypes 1/2a (30%), 1/2c (100%), and 3a (100%), and a 3-codon deletion (amino acid positions 738 to 740) seen in 57% of 4b isolates from fish-processing facilities. Caco-2 invasion assays showed that two isolates with the deletion were significantly more invasive than EGD-SmR (P<0.0001) and were either as (FF19-1) or more (FE13-1) invasive than a clinical control strain (08-5578) (P= 0.006). To examine whether serotype 1/2a was more likely to acquire mutations than other serotypes, strains were plated on agar with rifampin, revealing 4b isolates to be significantly more mutable than 1/2a, 1/2c, and 3a serotypes (P=0.0002). We also examined the ability of 33 strains to adapt to cold temperature following a downshift from 37°C to 4°C. Overall, three distinct coldadapting groups (CAG) were observed: 46% were fast (<70 h), 39% were intermediate (70 to 200 h), and 15% were slow (>200 h) adaptors. Intermediate CAG strains (70%) more frequently possessed inlA PMSCs than did fast (20%) and slow (10%) CAGs; in contrast, 87% of fast adaptors lacked inlA PMSCs. In conclusion, we report food chain-derived 1/2a and 4b serotypes with a 3-codon deletion possessing invasive behavior and the novel association of inlA genotypes encoding a full-length InlA with fast cold-adaptation phenotypes. © 2013, American Society for Microbiology.
|Journal series||Applied and Environmental Microbiology, ISSN 0099-2240, (A 40 pkt)|
|Publication size in sheets||0.5|
|ASJC Classification||; ; ;|
|Score|| = 35.0, 09-07-2020, ArticleFromJournal|
= 40.0, 09-07-2020, ArticleFromJournal
|Publication indicators||= 30; = 28; : 2013 = 1.392; : 2013 = 3.952 (2) - 2013=4.486 (5)|
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