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. 2022 Feb 21:12:796040.
doi: 10.3389/fmicb.2021.796040. eCollection 2021.

Virulence and Antibiotic Resistance Genes in Listeria monocytogenes Strains Isolated From Ready-to-Eat Foods in Chile

Julio Parra-Flores  1 , Ondrej Holý  2 , Fernanda Bustamante  3 , Sarah Lepuschitz  4 , Ariane Pietzka  4 , Alejandra Contreras-Fernández  5 , Claudia Castillo  6 , Catalina Ovalle  6 , María Paula Alarcón-Lavín  1 , Ariadnna Cruz-Córdova  7 , Juan Xicohtencatl-Cortes  7 , Jetsi Mancilla-Rojano  7   8 , Miriam Troncoso  9 , Guillermo Figueroa  9 , Werner Ruppitsch  4
Affiliations

Virulence and Antibiotic Resistance Genes in Listeria monocytogenes Strains Isolated From Ready-to-Eat Foods in Chile

Julio Parra-Flores et al. Front Microbiol. .

Abstract

Listeria monocytogenes is causing listeriosis, a rare but severe foodborne infection. Listeriosis affects pregnant women, newborns, older adults, and immunocompromised individuals. Ready-to-eat (RTE) foods are the most common sources of transmission of the pathogen This study explored the virulence factors and antibiotic resistance in L. monocytogenes strains isolated from ready-to-eat (RTE) foods through in vitro and in silico testing by whole-genome sequencing (WGS). The overall positivity of L. monocytogenes in RTE food samples was 3.1% and 14 strains were isolated. L. monocytogenes ST8, ST2763, ST1, ST3, ST5, ST7, ST9, ST14, ST193, and ST451 sequence types were identified by average nucleotide identity, ribosomal multilocus sequence typing (rMLST), and core genome MLST. Seven isolates had serotype 1/2a, five 1/2b, one 4b, and one 1/2c. Three strains exhibited in vitro resistance to ampicillin and 100% of the strains carried the fosX, lin, norB, mprF, tetA, and tetC resistance genes. In addition, the arsBC, bcrBC, and clpL genes were detected, which conferred resistance to stress and disinfectants. All strains harbored hlyA, prfA, and inlA genes almost thirty-two the showed the bsh, clpCEP, hly, hpt, iap/cwhA, inlA, inlB, ipeA, lspA, mpl, plcA, pclB, oat, pdgA, and prfA genes. One isolate exhibited a type 11 premature stop codon (PMSC) in the inlA gene and another isolate a new mutation (deletion of A in position 819). The Inc18(rep25), Inc18(rep26), and N1011A plasmids and MGEs were found in nine isolates. Ten isolates showed CAS-Type II-B systems; in addition, Anti-CRISPR AcrIIA1 and AcrIIA3 phage-associated systems were detected in three genomes. These virulence and antibiotic resistance traits in the strains isolated in the RTE foods indicate a potential public health risk for consumers.

Keywords: CRISPR-Cas; Listeria monocytogenes; ready-to-eat foods; resistance genes; virulence; whole-genome sequencing.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Minimum spanning tree (MST) of 14 Listeria monocytogenes strains from ready-to-eat foods isolated in Chile. L. monocytogenes strains with ST1, ST3, ST5, ST7, ST8, ST9, ST14, ST193, ST451, and ST2763 are of clinical and food origin. Calculation of the MST is based on the defined core genome multilocus sequence typing (cgMLST) scheme consisting of 1,701 target genes from Task templates for SeqSphere+ v. 7.8.0 (2021-7). Isolates are represented as colored circles according to the classical MLST. Black numbers are in accordance with the allelic difference between isolates. Isolates with closely related genotypes are marked as Cluster.
FIGURE 2
FIGURE 2
Distribution of virulence genes present in 14 L. monocytogenes strains isolated from ready-to-eat foods. Green boxes indicate the presence of the gene and black boxes its absence.
FIGURE 3
FIGURE 3
CRISPR-Cas systems identified in L. monocytogenes genomes. The identified systems belong to the CRISPR-Cas type II-B system, and some genomes show more than one array.
See this image and copyright information in PMC

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References

    1. Aballa A., Guariglia-Oropeza V., Wiedmann M., Boor K. (2019). Cross talk between SigB and PrfA in Listeria monocytogenes facilitates transitions between extra-and intracellular environments. Microbiol. Mol. Biol. Rev. 83:e00037. 10.1128/MMBR.00034-19 - DOI - PMC - PubMed
    1. Abdollahzadeh E., Mahdi S., Hosseini H., IraJian G., Allah E. (2016). Prevalence and molecular characterization of Listeria spp. and Listeria monocytogenes isolated from fish, shrimp, and cooked ready-to-eat (RTE) aquatic products in Iran. LWT 73 205–211. 10.1016/j.lwt.2016.06.020 - DOI
    1. Aljahdali N. H., Khajanchi B. K., Weston K., Deck J., Cox J., Singh R., et al. (2020). Genotypic and phenotypic characterization of incompatibility group FIB positive Salmonella enterica Serovar Typhimurium isolates from food animal sources. Genes 11:1307. 10.3390/genes11111307 - DOI - PMC - PubMed
    1. Allam M., Tau N., Smouse S. L., Mtshali P. S., Mnyameni F., Khumalo Z., et al. (2018). Whole-genome sequences of Listeria monocytogenes sequence type 6 isolates associated with a large foodborne outbreak in South Africa, 2017 to 2018. Genome Announc. 6:e00538-18. 10.1128/genomeA.00538-18 - DOI - PMC - PubMed
    1. Althaus D., Lehner A., Brisse S., Maury M., Tasara T., Stephan R. (2014). Characterization of Listeria monocytogenes strains isolated during 2011–2013 from human infections in Switzerland. Foodborne Pathog. Dis. 11 753–758. 10.1089/fpd.2014.1747 - DOI - PubMed