scholarly journals Characterization of the ELPhiS Prophage from Salmonella enterica Serovar Enteritidis Strain LK5

2012 ◽  
Vol 78 (6) ◽  
pp. 1785-1793 ◽  
Author(s):  
L. Farris Hanna ◽  
T. David Matthews ◽  
Elizabeth A. Dinsdale ◽  
David Hasty ◽  
Robert A. Edwards
Keyword(s):  
Salmonella Enterica ◽  
Bacterial Pathogens ◽  
Genomic Analysis ◽  
Bacterial Genomes ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Content Type ◽  
Transfer Genes ◽  
Screen Approach ◽  
Lysogenic Phage

ABSTRACTPhages are a primary driving force behind the evolution of bacterial pathogens by transferring a variety of virulence genes into their hosts. Similar to other bacterial genomes, theSalmonella entericaserovar Enteritidis LK5 genome contains several regions that are homologous to phages. Although genomic analysis demonstrated the presence of prophages, it was unable to confirm which phage elements within the genome were viable. Genetic markers were used to tag one of the prophages in the genome to allow monitoring of phage induction. Commonly used laboratory strains ofSalmonellawere resistant to phage infection, and therefore a rapid screen was developed to identify susceptible hosts. This approach showed that a genetically tagged prophage, ELPhiS (Enteritidis lysogenic phage S), was capable of infectingSalmonellaserovars that are diverse in host range and virulence and has the potential to laterally transfer genes between these serovars via lysogenic conversion. The rapid screen approach is adaptable to any system with a large collection of isolates and may be used to test the viability of prophages found by sequencing the genomes of various bacterial pathogens.

scholarly journals IncI1 Plasmids Carrying VariousblaCTX-MGenes Contribute to Ceftriaxone Resistance in Salmonella enterica Serovar Enteritidis in China

2015 ◽  
Vol 60 (2) ◽  
pp. 982-989 ◽  
Author(s):  
Marcus Ho-yin Wong ◽  
Biao Kan ◽  
Edward Wai-chi Chan ◽  
Meiying Yan ◽  
Sheng Chen
Keyword(s):  
Salmonella Enterica ◽  
Complete Sequence ◽  
Health Concern ◽  
Phenotypic Characterization ◽  
The Novel ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Content Type ◽  
Control And Prevention ◽  
Cephalosporin Resistance

ABSTRACTResistance to extended-spectrum β-lactams inSalmonella, in particular, in serotypes such asSalmonella entericaserovar Enteritidis that are frequently associated with clinical infections, is a serious public health concern. In this study, phenotypic characterization of 433 clinicalS. Enteritidis strains obtained from a nationwide collection of the Chinese Center for Disease Control and Prevention during the period from 2005 to 2010 depicted a trend of increasing resistance to ceftriaxone from 2008 onwards. Seventeen (4%) of the strains were found to be resistant to ceftriaxone, 7% were found to be resistant to ciprofloxacin, and 0.7% were found to be resistant to both ciprofloxacin and ceftriaxone. Most of the ceftriaxone-resistantS. Enteritidis strains (15/17) were genetically unrelated and originated from Henan Province. The complete sequence of an IncI1 plasmid, pSE115, which belonged to a novel sequence type, was obtained. This 87,255-bp IncI1 plasmid was found to harbor ablaCTX-M-14gene in a novel multidrug resistance region (MRR) within thetralocus. Although the majority of strains were also found to contain conjugative IncI1 plasmids with a size similar to that of pSE115 (∼90 kb) and harbor a variety ofblaCTX-Mgroup 1 and group 9 elements, the novel MRR site at thetralocus in pSE115 was not detectable in the other IncI1 plasmids. The findings from this study show that cephalosporin resistance inS. Enteritidis strains collected in China was mainly due to the dissemination of IncI1 plasmids carryingblaCTX-M, resembling the situation in which IncI1 plasmids serve as major vectors ofblaCTX-Mvariants in other members of theEnterobacteriaceae.

scholarly journals Naturally Occurring Motility-Defective Mutants of Salmonella enterica Serovar Enteritidis Isolated Preferentially from Nonhuman Rather than Human Sources

2011 ◽  
Vol 77 (21) ◽  
pp. 7740-7748 ◽  
Author(s):  
Lucía Yim ◽  
Laura Betancor ◽  
Arací Martínez ◽  
Clare Bryant ◽  
Duncan Maskell ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Intestinal Epithelial ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Transcriptional Responses ◽  
Content Type ◽  
Field Isolates ◽  
Specific Pcr ◽  
Human Intestinal Epithelial Cells ◽  
Natural Isolates ◽  
Cell Invasiveness

ABSTRACTSalmonellosis represents a worldwide health problem because it is one of the major causes of food-borne disease. Although motility is postulated as an importantSalmonellavirulence attribute, there is little information about variation in motility in natural isolates. Here we report the identification of a point mutation (T551 → G) inmotA, a gene essential for flagellar rotation, in severalSalmonella entericaserovar Enteritidis field isolates. This mutation results in bacteria that can biosynthesize structurally normal but paralyzed flagella and are impaired in their capacity to invade human intestinal epithelial cells. Introduction of a wild-type copy ofmotAinto one of these isolates restored both motility and cell invasiveness. ThemotAmutant triggered higher proinflammatory transcriptional responses than an aflagellate isolate in differentiated Caco-2 cells, suggesting that the paralyzed flagella are able to signal through pattern recognition receptors. A specific PCR was designed to screen for the T551 → G mutation in a collection of 266S. Enteritidis field isolates from a nationwide epidemic, comprising 194 from humans and 72 from other sources. We found that 72 of the 266 (27%) isolates were nonmotile, including 24.7% (48/194) of human and 33.3% (24/72) of food isolates. Among nonmotile isolates, 15 carried the T551 → G mutation and, significantly, 13 were recovered from food, including 7 from eggs, but only 2 were from human sources. These results suggest that the presence of paralyzed flagella may impair the ability ofS. Enteritidis to cause disease in the human host but does not prevent its ability to colonize chickens and infect eggs.

scholarly journals Virulence and Metabolic Characteristics of Salmonella enterica Serovar Enteritidis Strains with DifferentsefDVariants in Hens

2012 ◽  
Vol 78 (18) ◽  
pp. 6405-6412 ◽  
Author(s):  
Cesar A. Morales ◽  
Jean Guard ◽  
Roxana Sanchez-Ingunza ◽  
Devendra H. Shah ◽  
Mark Harrison
Keyword(s):  
Salmonella Enterica ◽  
Egg Production ◽  
The Body ◽  
Wild Type ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Blood Calcium ◽  
Content Type ◽  
Metabolic Characteristics ◽  
Wide Range ◽  
Metabolic Properties

ABSTRACTSalmonella entericaserovar Enteritidis is one of a fewSalmonella entericaserotypes that has SEF14 fimbriae encoded by thesefoperon, which consists of 4 cotranscribed genes,sefABCD, regulated bysefR. A parental strain was used to construct asefDmutant and its complement, and all 3 strains were compared for gene expression, metabolic properties, and virulence characteristics in hens. Transcription ofsefDby wild type was suppressed at 42°C and absent for the mutant under conditions where the complemented mutant had 103times higher transcription. Growth of the complemented mutant was restricted in comparison to that of the mutant and wild type. Hens infected with the wild type and mutant showed decreased blood calcium and egg production, but infection with the complemented mutant did not. Thus, the absence ofsefDcorrelated with increased metabolic capacity and enhanced virulence of the pathogen. These results suggest that any contribution thatsefDmakes to egg contamination is either unknown or would be limited to early transmission from the environment to the host. Absence ofsefD, either through mutation or by suppression of transcription at the body temperature of the host, may contribute to the virulence ofSalmonella entericaby facilitating growth on a wide range of metabolites.

scholarly journals Characterization of Epidemic IncI1-Iγ Plasmids Harboring Ambler Class A and C Genes in Escherichia coli and Salmonella enterica from Animals and Humans

2015 ◽  
Vol 59 (9) ◽  
pp. 5357-5365 ◽  
Author(s):  
Hilde Smith ◽  
Alex Bossers ◽  
Frank Harders ◽  
Guanghui Wu ◽  
Neil Woodford ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Phylogenetic Trees ◽  
Functional Study ◽  
Content Type ◽  
Gene Associations ◽  
Genes Encoding ◽  
Marked Resistance

ABSTRACTThe aim of the study was to identify the plasmid-encoded factors contributing to the emergence and spread of epidemic IncI1-Iγ plasmids obtained fromEscherichia coliandSalmonella entericaisolates from animal and human reservoirs. For this, 251 IncI1-Iγ plasmids carrying various extended-spectrum β-lactamase (ESBL) or AmpC β-lactamase genes were compared using plasmid multilocus sequence typing (pMLST). Thirty-two of these plasmids belonging to different pMLST types were sequenced using Roche 454 and Illumina platforms. Epidemic IncI1-Iγ plasmids could be assigned to various dominant clades, whereas rarely detected plasmids clustered together as a distinct clade. Similar phylogenetic trees were obtained using only the plasmid backbone sequences, showing that the differences observed between the plasmids belonging to distinct clades resulted mainly from differences between their backbone sequences. Plasmids belonging to the various clades differed particularly in the presence/absence of genes encoding partitioning and addiction systems, which contribute to stable inheritance during cell division and plasmid maintenance. Despite this, plasmids belonging to the various phylogenetic clades also showed marked resistance gene associations, indicating the circulation of successful plasmid-gene combinations. The variation intraYandexcAgenes found in IncI1-Iγ plasmids is conserved within pMLST sequence types and plays a role in incompatibility, although functional study is needed to elucidate the role of these genes in plasmid epidemiology.

Characterization of SEN3800-associated virulence of Salmonella enterica serovar Enteritidis phage type 8

2014 ◽  
Vol 65 (2) ◽  
pp. 631-637
Author(s):  
Daniel C. Shippy ◽  
Nicholas M. Eakley ◽  
Dareen M. Mikheil ◽  
Anna De La Cotera ◽  
Amin A. Fadl
Keyword(s):  
Salmonella Enterica ◽  
Phage Type ◽  
Salmonella Enterica Serovar Enteritidis

scholarly journals Characterization of Chicken Spleen Transcriptome after Infection with Salmonella enterica Serovar Enteritidis

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e48101 ◽  
Author(s):  
Marta Matulova ◽  
Jana Rajova ◽  
Lenka Vlasatikova ◽  
Jiri Volf ◽  
Hana Stepanova ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Chicken Spleen

scholarly journals Characterization of mcr-5-Harboring Salmonella enterica subsp. enterica Serovar Typhimurium Isolates from Animal and Food Origin in Germany

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Maria Borowiak ◽  
Jens A. Hammerl ◽  
Carlus Deneke ◽  
Jennie Fischer ◽  
Istvan Szabo ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Mobile Genetic Elements ◽  
Sequence Type ◽  
Content Type ◽  
Genetic Elements ◽  
Bacterial Chromosomes ◽  
Serovar Typhimurium

ABSTRACT We characterized eight mcr-5-positive Salmonella enterica subsp. enterica serovar Typhimurium sequence type 34 (ST34) isolates obtained from pigs and meat in Germany. Five plasmid types were identified harboring mcr-5 on Tn6452 or putative mobile insertion cassettes. The mobility of mcr-5 was confirmed by integration of Tn6452 into the bacterial chromosomes of two strains and the detection of conjugative mcr-5 plasmids. The association with mobile genetic elements might further enhance mcr-5 distribution.

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