Genomic Characterization of Novel Listeria monocytogenes Serotype 4b Variant Strains

This study was conducted to determine the prevalence and characteristics of Listeria monocytogenes in bovine colostrum in Japan. We collected bovine colostrum samples from 210 dams from 21 dairy farms in Hokkaido prefecture (Japan) between March and June 2009. L. monocytogenes was detected in samples from 6 (28.6%) of the 21 farms. Of the 210 samples, 16 (7.6%) were positive for L. monocytogenes. We recovered 80 L. monocytogenes isolates; 44 (55%) isolates were classified as serotype 1/2b and 36 (45%) were classified as serotype 4b. The isolates were susceptible to penicillin, ampicillin, amoxicillin, gentamicin, kanamycin, streptomycin, erythromycin, vancomycin, tetracycline, chloramphenicol, ciprofloxacin, and trimethoprimsulfamethoxazole. Pulsed-field gel electrophoresis (PFGE) characterization of the 80 isolates revealed six PFGE types. Two PFGE types corresponded to human listeriosis cases. Most L. monocytogenes isolates possessed virulence-associated genes (actA, hly, iap, inlA, inlC, mpl, plcA, plcB, opuCA, prfA, and clpC). One PFGE type isolate possessed an epidemic clone II marker. Our findings suggest that isolates from bovine colostrum have the potential to cause human and animal listeriosis. This is the first study on the prevalence and characteristics of L. monocytogenes isolated from bovine colostrum obtained from dairy farms. Our results have important implications for improving public health and elucidating the epidemiology of L. monocytogenes in bovine colostrum.

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Genomic characterization of the most barotolerant Listeria monocytogenes RO15 strain compared to reference strains used to evaluate food high pressure processing

BMC Genomics ◽

10.1186/s12864-020-06819-0 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Ilhan Cem Duru ◽

Margarita Andreevskaya ◽

Pia Laine ◽

Tone Mari Rode ◽

Anne Ylinen ◽

...

Keyword(s):

High Pressure ◽

Listeria Monocytogenes ◽

High Pressure Processing ◽

Genomic Characterization ◽

Reference Strains

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Genomic Characterization of Clinical Listeria monocytogenes Isolates in Beijing, China

Frontiers in Microbiology ◽

10.3389/fmicb.2021.751003 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xiaoai Zhang ◽

Yuzhu Liu ◽

Penghang Zhang ◽

Yanlin Niu ◽

Qian Chen ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Common Core ◽

Core Genome ◽

The United States ◽

Multidrug Resistant ◽

Human Pathogen ◽

Genomic Characterization ◽

Beijing China ◽

Insight Into

Listeria monocytogenes is a foodborne human pathogen that affects public health worldwide. Whole-genome sequencing (WGS) can classify L. monocytogenes isolates and identify virulence islands and resistance genes potentially influencing infectivity. Herein, WGS was used to assess 151 L. monocytogenes isolates from 120 cases of clinical infection in Beijing, China, between 2014 and 2018. Most isolates were either serogroup 1/2a,3a or serogroup 1/2b,3b,7, with 25 multilocus sequence typing (MLST) types (STs) represented, of which ST8, ST87, and ST5 were the most common. Core-genome MLST (cgMLST) grouped the 151 isolates into 116 cgMLST types. The discriminatory power of cgMLST was greater than other subtypes, revealing that isolates from the same patient were highly related (only differing at one allele). Eighty-six isolates formed 30 complexes with ≤ 7 cgMLST alleles between neighboring isolates, suggesting possible outbreaks. Compared with isolates in the United States, ST8, ST121, ST619, ST87, and ST155 isolates were grouped into unified clades. All 151 isolates were positive for common virulence-associated loci, and 26 lineage I isolates harbored the pathogenicity island 3 (LIPI-3) locus, while 42 lineage I isolates harbored the complete LIPI-4 locus. Eleven ST619 isolates had both LIPI-3 and LIPI-4. Among the 151 isolates, 13 were resistant to at least one antibiotic, and no multidrug-resistant isolates were identified. Resistance phenotypes correlated with genotypes, apart from two meropenem resistance isolates. The findings provided insight into the nature of L. monocytogenes strains currently causing clinical disease in Beijing, and WGS analysis indicated possible outbreaks.

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Characterization of Virulence Properties of Listeria monocytogenes Serotype 4b Strains of Different Origins

Zoonoses and Public Health ◽

10.1111/j.1863-2378.2008.01127.x ◽

2008 ◽

Vol 55 (5) ◽

pp. 242-248 ◽

Cited By ~ 7

Author(s):

H. Werbrouck ◽

N. Botteldoorn ◽

L. Ceelen ◽

A. Decostere ◽

M. Uyttendaele ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Serotype 4B ◽

Different Origins ◽

Virulence Properties

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Characterization of a Novel Group of Listeria Phages That Target Serotype 4b Listeria monocytogenes

Viruses ◽

10.3390/v13040671 ◽

2021 ◽

Vol 13 (4) ◽

pp. 671

Author(s):

Yaxiong Song ◽

Tracey L. Peters ◽

Daniel W. Bryan ◽

Lauren K. Hudson ◽

Thomas G. Denes

Keyword(s):

Listeria Monocytogenes ◽

Food Processing ◽

Biocontrol Agent ◽

Novel Species ◽

Morphological Characteristics ◽

Inhibitory Effect ◽

One Step ◽

Step Growth ◽

Serotype 4B

Listeria monocytogenes serotype 4b strains are the most prevalent clinical isolates and are widely found in food processing environments. Bacteriophages are natural viral predators of bacteria and are a promising biocontrol agent for L. monocytogenes. The aims of this study were to characterize phages that specifically infect serotype 4b strains and to assess their ability to inhibit the growth of serotype 4b strains. Out of 120 wild Listeria phages, nine phages were selected based on their strong lytic activity against the model serotype 4b strain F2365. These nine phages can be divided into two groups based on their morphological characteristics and host range. Comparison to previously characterized phage genomes revealed one of these groups qualifies to be defined as a novel species. Phages LP-020, LP-027, and LP-094 were selected as representatives of these two groups of phages for further characterization through one-step growth curve and inhibition of serotype 4b L. monocytogenes experiments. Listeria phages that target serotype 4b showed an inhibitory effect on the growth of F2365 and other serotype 4 strains and may be useful for biocontrol of L.monocytogenes in food processing environments.

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