scholarly journals Virulence Gene Sequencing Highlights Similarities and Differences in Sequences in Listeria monocytogenes Serotype 1/2a and 4b Strains of Clinical and Food Origin From 3 Different Geographic Locations

2018 ◽  
Vol 9 ◽  
Author(s):  
Sofia V. Poimenidou ◽  
Marion Dalmasso ◽  
Konstantinos Papadimitriou ◽  
Edward M. Fox ◽  
Panagiotis N. Skandamis ◽  
...  
2003 ◽  
Vol 185 (18) ◽  
pp. 5573-5584 ◽  
Author(s):  
Chaomei Zhang ◽  
Min Zhang ◽  
Jingliang Ju ◽  
Joseph Nietfeldt ◽  
John Wise ◽  
...  

ABSTRACT Thirteen different serotypes of Listeria monocytogenes can be distinguished on the basis of variation in somatic and flagellar antigens. Although the known virulence genes are present in all serotypes, greater than 90% of human cases of listeriosis are caused by serotypes 1/2a, 1/2b, and 4b and nearly all outbreaks of food-borne listeriosis have been caused by serotype 4b strains. Phylogenetic analysis of these three common clinical serotypes places them into two different lineages, with serotypes 1/2b and 4b belonging to lineage I and 1/2a belonging to lineage II. To begin examining evolution of the genome in these serotypes, DNA microarray analysis was used to identify lineage-specific and serotype-specific differences in genome content. A set of 44 strains representing serotypes 1/2a, 1/2b, and 4b was probed with a shotgun DNA microarray constructed from the serotype 1/2a strain 10403s. Clones spanning 47 different genes in 16 different contiguous segments relative to the lineage II 1/2a genome were found to be absent in all lineage I strains tested (serotype 4b and 1/2b) and an additional nine were altered exclusively in 4b strains. Southern hybridization confirmed that conserved alterations were, in all but two loci, due to absence of the segments from the genome. Genes within these contiguous segments comprise five functional categories, including genes involved in synthesis of cell surface molecules and regulation of virulence gene expression. Phylogenetic reconstruction and examination of compositional bias in the regions of difference are consistent with a model in which the ancestor of the two lineages had the 1/2 somatic serotype and the regions absent in the lineage I genome arose by loss of ancestral sequences.


1980 ◽  
Vol 152 (4) ◽  
pp. 853-868 ◽  
Author(s):  
D H Rubin ◽  
B N Fields

The mammalian reoviruses (serotype 1, strain Lang and serotype 3, strain Dearing) differ in their sensitivity to digestion by chymotrypsin. We have found that the M2 double-stranded RNA (dsRNA) genome segment (encoding the micro1C outer capsid polypeptide) is responsible for this property. In addition to determining response to protease treatement in vitro, we have found that the M2 genome segment also determines the ability of these two viruses successfully to initiate local and systemic infection in newborn mice after peroral inoculation. Thus the M2 dsRNA segment defines a new virulence gene of the mammalian reoviruses.


2014 ◽  
Vol 77 (2) ◽  
pp. 254-261 ◽  
Author(s):  
MARIOS MATARAGAS ◽  
ANNA GREPPI ◽  
KALLIOPI RANTSIOU ◽  
LUCA COCOLIN

A Listeria monocytogenes subgenomic array, targeting 54 genes involved in the adhesion, adaptation, intracellular life cycle, invasion, and regulation of the infection cycle was used to investigate the gene expression patterns of acid- and salt-stressed Listeria cells after exposure to conditions similar to those in gastric and pancreatic fluids. Three L. monocytogenes strains, one laboratory reference strain (EGDe) and two food isolates (wild strain 12 isolated from milk and wild strain 3 isolated from fermented sausage), were used during the studies. Differences in the expressed genes were observed between the gastric and pancreatic treatments and also between the serotypes. Increased transcripts were observed of the genes belonging to the adaptation and regulation group for serotype 4b (strain 12) and to the invasion and regulation group for serotype 1/2a (strain EGDe). Interestingly, no significantly differentially expressed genes were found for serotype 3c (strain 3) in most cases. The genes related to adaptation (serotype 1/2a) and to intracellular life cycle and invasion (serotype 4b) were down-regulated in order to cope with the hostile environment of the gastric and pancreatic fluids. These findings may provide experimental evidence for the dominance of serotypes 1/2a and 4b in clinical cases of listeriosis and for the sporadic occurrence of serotype 3c.


2016 ◽  
Vol 4 (5) ◽  
Author(s):  
Arthur W. Pightling ◽  
Hugh Rand ◽  
Errol Strain ◽  
Franco Pagotto

Listeria monocytogenesis a pathogenic bacterium of importance to public health and food safety agencies. We present the genome sequence of the serotype 1/2aL. monocytogenesfood isolate HPB913, which was collected in Canada in 1993 as part of an investigation into a sporadic case of foodborne illness.


2005 ◽  
Vol 68 (2) ◽  
pp. 411-415 ◽  
Author(s):  
SATOKO HANDA ◽  
BON KIMURA ◽  
HAJIME TAKAHASHI ◽  
TAKASHI KODA ◽  
KAZUO HISA ◽  
...  

The incidence of Listeria monocytogenes in raw fish, shellfish, and fish roe was investigated in seafood products collected from randomly selected retail stores in and around Tokyo, Japan. Of the 10 samples of 208 examined found positive for L. monocytogenes by mini-VIDAS LMO, seven were fish roe (cod, salmon) and three were minced tuna. Three serotypes (1/2a, 1/2b, 3b) were detected among the isolated strains; serotype 1/2a was predominant (8 of 10).


2002 ◽  
Vol 184 (15) ◽  
pp. 4177-4186 ◽  
Author(s):  
Peter Lauer ◽  
Man Yin Nora Chow ◽  
Martin J. Loessner ◽  
Daniel A. Portnoy ◽  
Richard Calendar

ABSTRACT Two site-specific shuttle integration vectors were developed with two different chromosomal bacteriophage integration sites to facilitate strain construction in Listeria monocytogenes. The first vector, pPL1, utilizes the listeriophage U153 integrase and attachment site within the comK gene for chromosomal insertion. pPL1 contains a useful polylinker, can be directly conjugated from Escherichia coli into L. monocytogenes, forms stable, single-copy integrants at a frequency of ∼10−4 per donor cell, and can be used in the L. monocytogenes 1/2 and 4b serogroups. Methods for curing endogenous prophages from the comK attachment site in 10403S-derived strains were developed. pPL1 was used to introduce the hly and actA genes at comK-attBB′ in deletion strains derived from 10403S and SLCC-5764. These strains were tested for second-site complementation in hemolysin assays, plaquing assays, and cell extract motility assays. Unlike plasmid-complemented strains, integrated pPL1-complemented strains were fully virulent in the mouse 50% lethal dose assay. Additionally, the PSA phage attachment site on the L. monocytogenes chromosome was characterized, and pPL1 was modified to integrate at this site. The listeriophage PSA integrates in the 3′ end of an arginine tRNA gene. There are 17 bp of DNA identity between the bacterial and phage attachment sites. The PSA prophage DNA sequence reconstitutes a complete tRNAArg gene. The modified vector, pPL2, was integration proficient at the same frequency as pPL1 in common laboratory serotype 1/2 strains as well as serotype 4b strains.


2016 ◽  
Vol 26 (6) ◽  
pp. 369-380 ◽  
Author(s):  
Takfarinas Kentache ◽  
Eliane Milohanic ◽  
Thanh Nguyen Cao ◽  
Abdelhamid Mokhtari ◽  
Francine Moussan Aké ◽  
...  

Transposon insertion into <i>Listeria monocytogenes lmo2665</i>, which encodes an EIIC of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS), was found to prevent <smlcap>D</smlcap>-arabitol utilization. We confirm this result with a deletion mutant and show that Lmo2665 is also required for <smlcap>D</smlcap>-xylitol utilization. We therefore called this protein EIIC<sup>Axl</sup>. Both pentitols are probably catabolized via the pentose phosphate pathway (PPP) because <i>lmo2665</i> belongs to an operon, which encodes the three PTS<sup>Axl</sup> components, two sugar-P dehydrogenases, and most PPP enzymes. The two dehydrogenases oxidize the pentitol-phosphates produced during PTS-catalyzed transport to the PPP intermediate xylulose-5-P. <i>L. monocytogenes</i> contains another PTS, which exhibits significant sequence identity to PTS<sup>Axl</sup>. Its genes are also part of an operon encoding PPP enzymes. Deletion of the EIIC-encoding gene <i>(lmo0508)</i> affected neither <smlcap>D</smlcap>-arabitol nor <smlcap>D</smlcap>-xylitol utilization, although <smlcap>D</smlcap>-arabitol induces the expression of this operon. Both operons are controlled by MtlR/LicR-type transcription activators (Lmo2668 and Lmo0501, respectively). Phosphorylation of Lmo0501 by the soluble PTS<sup>Axl</sup> components probably explains why <smlcap>D</smlcap>-arabitol also induces the second pentitol operon. Listerial virulence genes are submitted to strong repression by PTS sugars, such as glucose. However, <smlcap>D</smlcap>-arabitol inhibited virulence gene expression only at high concentrations, probably owing to its less efficient utilization compared to glucose.


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