scholarly journals Distribution of insertion sequence IS200 among different clonal lines of the related Salmonella serotypes Livingstone and Eimsbuettel

1998 ◽  
Vol 47 (9) ◽  
pp. 791-797 ◽  
Author(s):  
P. B. Crichton ◽  
D. C. Old ◽  
H. F. Morphy
Keyword(s):  
Insertion Sequence ◽  
Salmonella Serotypes ◽  
Clonal Lines

The Effectiveness of Methanolic Extracts of Five Plants on Different Salmonella Isolates

2020 ◽  
Keyword(s):  
Multidrug Resistance ◽  
Salmonella Enteritidis ◽  
Microbial Growth ◽  
Herbal Extracts ◽  
Antibacterial Compounds ◽  
Natural Substances ◽  
Methanolic Extracts ◽  
Bacterial Antibiotic Resistance ◽  
Salmonella Serotypes ◽  
Multiple Challenges

Salmonellosis is known to be one of important issues that affect poultry industry as well as it can affect human health. Recently, multiple challenges are facing the use of natural antibacterial compounds, such as herbal extracts to overcome the massive increase in bacterial antibiotic resistance. Different Salmonella serotypes were recovered throughout examination of diarrheic poultry. These strains showed multidrug resistance by disc diffusion methods also, the resistance genes qnrS and aac (6′)-Ib-cr were detected in S. Enteritidis and S.Typhimurium which isolated from broiler's organs and muscles. The methanolic extracts of five plants (Alhagi maurorum, Conyza dioscoridis, Coriander sativum, Caracuma longa and Cuminum cyminum) were tested for their antibacterial activity against different isolated Salmonella serotypes using minimum inhibitory concentrations (MIC). Conyza dioscoridis was the most effective extract retarding microbial growth of Salmonella Enteritidis, while other plant extracts showed variable antimicrobial activity. These results are promising in the way of replacing the antibiotic therapy with natural substances to overcome the multidrug resistance.

scholarly journals The Functional Consequences of the Novel Ribosomal Pausing Site in SARS-CoV-2 Spike Glycoprotein RNA

2021 ◽  
Vol 22 (12) ◽  
pp. 6490
Author(s):  
Olga A. Postnikova ◽  
Sheetal Uppal ◽  
Weiliang Huang ◽  
Maureen A. Kane ◽  
Rafael Villasmil ◽  
...  
Keyword(s):  
Amino Acid ◽  
Insertion Sequence ◽  
Experimental Studies ◽  
Spike Protein ◽  
Spike Glycoprotein ◽  
Furin Cleavage ◽  
New Host ◽  
S Protein ◽  
Furin Cleavage Site ◽  
Ribosome Pausing

The SARS-CoV-2 Spike glycoprotein (S protein) acquired a unique new 4 amino acid -PRRA- insertion sequence at amino acid residues (aa) 681–684 that forms a new furin cleavage site in S protein as well as several new glycosylation sites. We studied various statistical properties of the -PRRA- insertion at the RNA level (CCUCGGCGGGCA). The nucleotide composition and codon usage of this sequence are different from the rest of the SARS-CoV-2 genome. One of such features is two tandem CGG codons, although the CGG codon is the rarest codon in the SARS-CoV-2 genome. This suggests that the insertion sequence could cause ribosome pausing as the result of these rare codons. Due to population variants, the Nextstrain divergence measure of the CCU codon is extremely large. We cannot exclude that this divergence might affect host immune responses/effectiveness of SARS-CoV-2 vaccines, possibilities awaiting further investigation. Our experimental studies show that the expression level of original RNA sequence “wildtype” spike protein is much lower than for codon-optimized spike protein in all studied cell lines. Interestingly, the original spike sequence produces a higher titer of pseudoviral particles and a higher level of infection. Further mutagenesis experiments suggest that this dual-effect insert, comprised of a combination of overlapping translation pausing and furin sites, has allowed SARS-CoV-2 to infect its new host (human) more readily. This underlines the importance of ribosome pausing to allow efficient regulation of protein expression and also of cotranslational subdomain folding.

scholarly journals Global patterns in genomic diversity underpinning the evolution of insecticide resistance in the aphid crop pest Myzus persicae

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Kumar Saurabh Singh ◽  
Erick M. G. Cordeiro ◽  
Bartlomiej J. Troczka ◽  
Adam Pym ◽  
Joanna Mackisack ◽  
...  
Keyword(s):  
Host Plant ◽  
Myzus Persicae ◽  
Resistance Mechanisms ◽  
Genomic Diversity ◽  
Resistance Mutations ◽  
Host Plant Adaptation ◽  
Repeated Evolution ◽  
Evolution Of Resistance ◽  
Selective Forces ◽  
Clonal Lines

AbstractThe aphid Myzus persicae is a destructive agricultural pest that displays an exceptional ability to develop resistance to both natural and synthetic insecticides. To investigate the evolution of resistance in this species we generated a chromosome-scale genome assembly and living panel of >110 fully sequenced globally sampled clonal lines. Our analyses reveal a remarkable diversity of resistance mutations segregating in global populations of M. persicae. We show that the emergence and spread of these mechanisms is influenced by host–plant associations, uncovering the widespread co‐option of a host-plant adaptation that also offers resistance against synthetic insecticides. We identify both the repeated evolution of independent resistance mutations at the same locus, and multiple instances of the evolution of novel resistance mechanisms against key insecticides. Our findings provide fundamental insights into the genomic responses of global insect populations to strong selective forces, and hold practical relevance for the control of pests and parasites.

Synthesis of three Salmonella epitopes for biosensor studies of carbohydrate–antibody interactions

2002 ◽  
Vol 80 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Henry N Yu ◽  
Chang-Chun Ling ◽  
David R Bundle
Keyword(s):  
Key Words ◽  
Self Assembled Monolayers ◽  
Antigenic Determinants ◽  
Amino Group ◽  
Assembled Monolayers ◽  
Construction Of Self ◽  
Terminal Amino ◽  
Salmonella Serotypes ◽  
O Antigens ◽  
Antibody Interactions

Disaccharides 1-3 corresponding to the antigenic determinants of Salmonella serotypes A, B, and D1 were synthesized in a form suited for use in biosensors. The disaccharide determinants each contain a unique 3,6-dideoxyhexose, namely abequose (3,6-dideoxy-D-xylo-hexose), paratose (3,6-dideoxy-D-ribohexose), and tyvelose (3,6-dideoxy-D-arabino-hexose), are α-linked to the 3-position of D-mannopyranose. The disaccharides were further derivatized with a linear aglycon that has a terminal amino group, and can be readily coupled to pertinent chains carrying a terminal thiol for the construction of self-assembled monolayers (SAMs). Efficient routes that employed a single 3,6-dideoxygenation step were developed for the synthesis of paratoside 15 and tyveloside 22.Key words: Salmonella O-antigens, lipopolysaccharide, abequose, paratose, tyvelose, 3,6-dideoxyhexose, deoxygenation, glycoside tethers, immobilization via pentenyl glycosides.

scholarly journals Distribution of the ermG Gene among Bacterial Isolates from Porcine Intestinal Contents

2005 ◽  
Vol 71 (8) ◽  
pp. 4930-4934 ◽  
Author(s):  
Yanping Wang ◽  
Gui-Rong Wang ◽  
Nadja B. Shoemaker ◽  
Terence R. Whitehead ◽  
Abigail A. Salyers
Keyword(s):  
Insertion Sequence ◽  
Bacillus Sphaericus ◽  
Gram Positive ◽  
Sequence Element ◽  
Conjugative Transposon ◽  
Gram Positive Bacteria ◽  
First Finding ◽  
Intestinal Contents ◽  
Porcine Feces ◽  
Insertion Sequence Element

ABSTRACT The ermG gene was first found in the soil bacterium Bacillus sphaericus. More recently, it was found in several human intestinal Bacteroides species. We report here the first finding of ermG genes in gram-positive bacteria isolated from porcine feces and from under-barn manure pits used to store porcine wastes. The porcine ermG sequences were identical to the sequence of the B. sphaericus ermG gene except that six of the seven ermG-containing strains contained an insertion sequence element insertion in the C-terminal end of the gene. The porcine ermG genes were found in three different gram-positive genera, an indication that it is possible that the gene is being spread by horizontal gene transfer. A segment of a Bacteroides conjugative transposon that carries an ermG gene cross-hybridized with DNA from six of the seven porcine isolates, but the restriction patterns in the porcine strains were different from that of the Bacteroides conjugative transposon.

scholarly journals Salmonellas in sewage. A study in latent human infection

1969 ◽  
Vol 67 (3) ◽  
pp. 517-523 ◽  
Author(s):  
R. W. S. Harvey ◽  
T. H. Price ◽  
D. W. Foster ◽  
W. C. Griffiths
Keyword(s):  
Technical Assistance ◽  
Human Infection ◽  
Reference Laboratory ◽  
Salmonella Infection ◽  
Technical Success ◽  
Sewerage System ◽  
The Public ◽  
Multiple Sampling ◽  
Paratyphi B ◽  
Salmonella Serotypes

SUMMARYIn a residential estate of 4000 persons, containing neither industry nor retail butchers shops, salmonellas were regularly found in the sewerage system. They were frequently found in the sewage of a portion of the estate housing 1000 persons. The range of serotypes found was wide and some types suggested an exotic origin. No overt salmonella infection in the estate was reported during the period of survey, although local general practitioners had been previously alerted. Overt infection due to serotypes found in the survey were, however, reported in other areas of Glamorgan. Multiple sampling points in the sewerage system and a serological technique for examining samples contaminated with multiple salmonella serotypes were essential for the technical success of the survey.We should like to thank Prof. Scott Thomson for his advice in the preparation of this paper; Dr E. S. Anderson of the Central Enteric Reference Laboratory and Bureau, Colindale, for phage-typing the strains of S. typhimurium and S. paratyphi B; and Dr G. J. G. King of the Public Health Laboratory, Bournemouth, for identifying the serotypes isolated. We should also like to thank Mr T. R. Liddington and Mr J. H. Price for their technical assistance.

scholarly journals Bias between the Left and Right Inverted Repeats during IS911 Targeted Insertion

2008 ◽  
Vol 190 (18) ◽  
pp. 6111-6118 ◽  
Author(s):  
P. Rousseau ◽  
C. Loot ◽  
C. Turlan ◽  
S. Nolivos ◽  
M. Chandler
Keyword(s):  
Insertion Sequence ◽  
Regulatory Protein ◽  
Open Reading Frames ◽  
Inverted Repeats ◽  
Functional Differences ◽  
Left And Right ◽  
Ordered Assembly ◽  
Overlapping Open Reading Frames ◽  
Reading Frames

ABSTRACT IS911 is a bacterial insertion sequence composed of two consecutive overlapping open reading frames (ORFs [orfA and orfB]) encoding the transposase (OrfAB) as well as a regulatory protein (OrfA). These ORFs are bordered by terminal left and right inverted repeats (IRL and IRR, respectively) with several differences in nucleotide sequence. IS911 transposition is asymmetric: each end is cleaved on one strand to generate a free 3′-OH, which is then used as the nucleophile in attacking the opposite insertion sequence (IS) end to generate a free IS circle. This will be inserted into a new target site. We show here that the ends exhibit functional differences which, in vivo, may favor the use of one compared to the other during transposition. Electromobility shift assays showed that a truncated form of the transposase [OrfAB(1-149)] exhibits higher affinity for IRR than for IRL. While there was no detectable difference in IR activities during the early steps of transposition, IRR was more efficient during the final insertion steps. We show here that the differential activities between the two IRs correlate with the different affinities of OrfAB(1-149) for the IRs during assembly of the nucleoprotein complexes leading to transposition. We conclude that the two inverted repeats are not equivalent during IS911 transposition and that this asymmetry may intervene to determine the ordered assembly of the different protein-DNA complexes involved in the reaction.

scholarly journals Identification and sequence analysis of IS6501, an insertion sequence in Brucella spp.: relationship between genomic structure and the number of IS6501 copies

1993 ◽  
Vol 139 (12) ◽  
pp. 3265-3273 ◽  
Author(s):  
S. Ouahrani ◽  
S. Michaux ◽  
J. S. Widada ◽  
G. Bourg ◽  
R. Tournebize ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Insertion Sequence ◽  
Genomic Structure
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