scholarly journals Characterization of Salmonella enterica serovar Typhimurium conjugative plasmids transferring resistance to antibiotics and their interaction with the virulence plasmid

2008 ◽  
Vol 62 (5) ◽  
pp. 938-941 ◽  
Author(s):  
H. Hradecka ◽  
D. Karasova ◽  
I. Rychlik
2008 ◽  
Vol 52 (12) ◽  
pp. 4514-4517 ◽  
Author(s):  
Ana Herrero ◽  
M. Carmen Mendoza ◽  
Rosaura Rodicio ◽  
M. Rosario Rodicio

ABSTRACT pUO-StVR2 is a virulence-resistance plasmid which originated from pSLT of Salmonella enterica serovar Typhimurium through acquisition of a complex resistance island, flanked by regions that provide a toxin-antitoxin system and an iron uptake system. The presence of resistance and virulence determinants on the same plasmid allows coselection of both properties, potentially increasing health risks.


2003 ◽  
Vol 185 (3) ◽  
pp. 991-1000 ◽  
Author(s):  
C. W. Bouwman ◽  
M. Kohli ◽  
A. Killoran ◽  
G. A. Touchie ◽  
R. J. Kadner ◽  
...  

ABSTRACT Disulfide oxidoreductases are viewed as foldases that help to maintain proteins on productive folding pathways by enhancing the rate of protein folding through the catalytic incorporation of disulfide bonds. SrgA, encoded on the virulence plasmid pStSR100 of Salmonella enterica serovar Typhimurium and located downstream of the plasmid-borne fimbrial operon, is a disulfide oxidoreductase. Sequence analysis indicates that SrgA is similar to DsbA from, for example, Escherichia coli, but not as highly conserved as most of the chromosomally encoded disulfide oxidoreductases from members of the family Enterobacteriaceae. SrgA is localized to the periplasm, and its disulfide oxidoreductase activity is dependent upon the presence of functional DsbB, the protein that is also responsible for reoxidation of the major disulfide oxidoreductase, DsbA. A quantitative analysis of the disulfide oxidoreductase activity of SrgA showed that SrgA was less efficient than DsbA at introducing disulfide bonds into the substrate alkaline phosphatase, suggesting that SrgA is more substrate specific than DsbA. It was also demonstrated that the disulfide oxidoreductase activity of SrgA is necessary for the production of plasmid-encoded fimbriae. The major structural subunit of the plasmid-encoded fimbriae, PefA, contains a disulfide bond that must be oxidized in order for PefA stability to be maintained and for plasmid-encoded fimbriae to be assembled. SrgA efficiently oxidizes the disulfide bond of PefA, while the S. enterica serovar Typhimurium chromosomally encoded disulfide oxidoreductase DsbA does not. pefA and srgA were also specifically expressed at pH 5.1 but not at pH 7.0, suggesting that the regulatory mechanisms involved in pef gene expression are also involved in srgA expression. SrgA therefore appears to be a substrate-specific disulfide oxidoreductase, thus explaining the requirement for an additional catalyst of disulfide bond formation in addition to DsbA of S. enterica serovar Typhimurium.


2013 ◽  
Vol 19 (13) ◽  
pp. 1494-1506 ◽  
Author(s):  
Mark Shepherd ◽  
Begoña Heras ◽  
Maud E. S. Achard ◽  
Gordon J. King ◽  
M. Pilar Argente ◽  
...  

2002 ◽  
Vol 46 (5) ◽  
pp. 1604-1606 ◽  
Author(s):  
Cheng-Hsun Chiu ◽  
Chishih Chu ◽  
Lin-Hui Su ◽  
Wan-Yu Wu ◽  
Tsu-Lan Wu

ABSTRACT A Salmonella enterica serovar Typhimurium strain that harbored a plasmid carrying a TEM-1-type β-lactamase gene was isolated from the blood and cerebrospinal fluid of an infant with meningitis. This 3.2-kb plasmid was further characterized to be a nonconjugative pGEM series cloning vector containing a foreign insert. The strain was likely laboratory derived and contaminated the environment before it caused the infection.


2008 ◽  
Vol 190 (24) ◽  
pp. 8155-8162 ◽  
Author(s):  
Fiona J. Cooke ◽  
Derek J. Brown ◽  
Maria Fookes ◽  
Derek Pickard ◽  
Alasdair Ivens ◽  
...  

ABSTRACT Salmonella enterica serovar Typhimurium definitive phage type 104 (DT104) has caused significant morbidity and mortality in humans and animals for almost three decades. We completed the full DNA sequence of one DT104 strain, NCTC13348, and showed that significant differences between the genome of this isolate and the genome of the previously sequenced strain Salmonella serovar Typhimurium LT2 are due to integrated prophage elements and Salmonella genomic island 1 encoding antibiotic resistance genes. Thirteen isolates of Salmonella serovar Typhimurium DT104 with different pulsed-field gel electrophoresis (PFGE) profiles were analyzed by using multilocus sequence typing (MLST), plasmid profiling, hybridization to a pan-Salmonella DNA microarray, and prophage-based multiplex PCR. All the isolates belonged to a single MLST type, sequence type ST19. Microarray data demonstrated that the gene contents of the 13 DT104 isolates were remarkably conserved. The PFGE DNA fragment size differences in these isolates could be explained to a great extent by differences in the prophage and plasmid contents. Thus, here the nature of variation in different Salmonella serovar Typhimurium DT104 isolates is further defined at the gene and whole-genome levels, illustrating how this phage type evolves over time.


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