scholarly journals Phage Mediate Bacterial Self Recognition

2018 ◽  
Author(s):  
Sooyeon Song ◽  
Yunxue Guo ◽  
Jun-Seob Kim ◽  
Xiaoxue Wang ◽  
Thomas K. Wood
Keyword(s):  
Kin Recognition ◽  
Group Behavior ◽  
Lytic Phage ◽  
Bacterial Cells ◽  
Demarcation Line ◽  
E Coli ◽  
Self Recognition ◽  
The Family ◽  
K 12

AbstractCells are social, and self-recognition is an important and conserved aspect of group behavior where cells assist kin and antagonize non-kin to conduct group behavior such as foraging for food and biofilm formation. However, the role of the common bacterial cohabitant, phage, in kin recognition, has not been explored. Here we find that a boundary (demarcation line) is formed between different swimmingEscherichia colistrains but not between identical clones; hence, motile bacterial cells discriminate between self and non-self. The basis for this self-recognition is a novel, 49 kb, T1-type, lytic phage of the family siphoviridae (named here SW1) that controls formation of the demarcation line by utilizing one of the host’s cryptic prophage proteins, YfdM, to propagate. Critically, SW1 increases the fitness ofE. coliK-12 compared to the identical strain that lacks the phage. Therefore, bacteria use phage to recognize kin.

scholarly journals Evolution of Bacterial Global Modulators: Role of a Novel H-NS Paralogue in the EnteroaggregativeEscherichia coliStrain 042

mSystems ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
A. Prieto ◽  
M. Bernabeu ◽  
S. Aznar ◽  
S. Ruiz-Cruz ◽  
A. Bravo ◽  
...  
Keyword(s):  
Protein A ◽  
Bacterial Cells ◽  
Gene Encoding ◽  
Specific Expression ◽  
Protein Targets ◽  
Global Regulators ◽  
E Coli ◽  
The Family ◽  
Regulatory Properties

ABSTRACTBacterial genomes sometimes contain genes that code for homologues of global regulators, the function of which is unclear. In members of the familyEnterobacteriaceae, cells express the global regulator H-NS and its paralogue StpA. InEscherichia coli, out of providing a molecular backup for H-NS, the role of StpA is poorly characterized. The enteroaggregativeE. colistrain 042 carries, in addition to thehnsandstpAgenes, a third gene encoding anhnsparalogue (hns2). We present in this paper information about its biological function. Transcriptomic analysis has shown that the H-NS2 protein targets a subset of the genes targeted by H-NS. Genes targeted by H-NS2 correspond mainly with horizontally transferred (HGT) genes and are also targeted by the Hha protein, a fine-tuner of H-NS activity. Compared with H-NS, H-NS2 expression levels are lower. In addition, H-NS2 expression exhibits specific features: it is sensitive to the growth temperature and to the nature of the culture medium. This novel H-NS paralogue is widespread within theEnterobacteriaceae.IMPORTANCEGlobal regulators such as H-NS play key relevant roles enabling bacterial cells to adapt to a changing environment. H-NS modulates both core and horizontally transferred (HGT) genes, but the mechanism by which H-NS can differentially regulate these genes remains to be elucidated. There are several instances of bacterial cells carrying genes that encode homologues of the global regulators. The question is what the roles of these proteins are. We noticed that the enteroaggregativeE. colistrain 042 carries a new hitherto uncharacterized copy of thehnsgene. We decided to investigate why this pathogenicE. colistrain requires an extra H-NS paralogue, termed H-NS2. In our work, we show that H-NS2 displays specific expression and regulatory properties. H-NS2 targets a subset of H-NS-specific genes and may help to differentially modulate core and HGT genes by the H-NS cellular pool.

The Local Sanarelli-Shwartzman Phenomenon in Rats Induced by Human Leukaemic Cells

1973 ◽  
Vol 29 (02) ◽  
pp. 353-362
Author(s):  
J Lisiewicz ◽  
A Pituch ◽  
J. A Litwin
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Intravenous Injection ◽  
Peripheral Blood ◽  
Lymphocytic Leukaemia ◽  
Acute Myeloblastic Leukaemia ◽  
Demarcation Line ◽  
E Coli ◽  
Leukaemic Cells ◽  
Shwartzman Phenomenon

SummaryThe local Sanarelli-Shwartzman phenomenon (SSP-L) in the skin of 30 rats was induced by an intr a cutaneous sensitizing injection of leukaemic leucocytes isolated from the peripheral blood of patients with chronic lymphocytic leukaemia (CLL), acute myeloblastic leukaemia (AL) and chronic granulocytic leukaemia (CGL) and challenged by an intravenous injection of 100(μ of E. coli endotoxin. SSP-L was observed in 7 rats after injection of CLL lymphocytes and in 6 and 2 rats after AL myeloblasts and the CGL granulocytes, respectively. The lesions in the skin after AL myeloblasts appeared in a shorter time and were of longer duration compared with those observed after CLL lymphocytes and CGL granulocytes. Histologically, the lesions consisted of areas of destruction in the superficial layers of the skin ; the demarcation line showed the presence of neutrophils, macrophages and erythrocytes. Haemorrhages and fibrin deposits near the demarcation line were larger after injection of CLL lymphocytes and AL myeloblasts than after CGL granulocytes. The possible role of leucocyte procoagulative substances in the differences observed have been discussed.

scholarly journals The Real-Time-Based Assessment of the Microbial Killing by the Antimicrobial Compounds of Neutrophils

2011 ◽  
Vol 11 ◽  
pp. 2382-2390 ◽  
Author(s):  
J. T. Atosuo ◽  
E.-M. Lilius
Keyword(s):  
Real Time ◽  
Antimicrobial Agents ◽  
Hypochlorous Acid ◽  
Bacterial Cells ◽  
Photorhabdus Luminescens ◽  
Bacterial Luciferase ◽  
E Coli ◽  
High Concentrations ◽  
Time Basis ◽  
K 12

A recombinantEscherichia coliK-12 strain, transformed with a modified bacterial luciferase gene (luxABCDE) fromPhotorhabdus luminescens, was constructed in order to monitor the activity of various antimicrobial agents on a real-time basis. ThisE. coli-lux emitted, without any addition of substrate, constitutive bioluminescence (BL), which correlated to the number of viable bacterial cells. The decrease in BL signal correlated to the number of killed bacterial cells. Antimicrobial activity of hydrogen peroxide (H2O2) and myeloperoxidase (MPO) was assessed. In high concentrations, H2O2alone had a bacteriocidic function and MPO enhanced this killing by forming hypochlorous acid (HOCl). Taurine, the known HOCl scavenger, blocked the killing by MPO. WhenE. coli-lux was incubated with neutrophils, similar killing kinetics was recorded as in H2O2/MPO experiments. The opsonization of bacteria enhanced the killing, and the maximum rate of the MPO release from lysosomes coincided with the onset of the killing.

scholarly journals Regulatory Role of PlaR (YiaJ) for Plant Utilization in Escherichia coli K-12

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tomohiro Shimada ◽  
Yui Yokoyama ◽  
Takumi Anzai ◽  
Kaneyoshi Yamamoto ◽  
Akira Ishihama
Keyword(s):  
Escherichia Coli ◽  
Genetic System ◽  
Regulatory Role ◽  
E Coli ◽  
Warm Blooded Animal ◽  
Plant Utilization ◽  
K 12

AbstractOutside a warm-blooded animal host, the enterobacterium Escherichia coli K-12 is also able to grow and survive in stressful nature. The major organic substance in nature is plant, but the genetic system of E. coli how to utilize plant-derived materials as nutrients is poorly understood. Here we describe the set of regulatory targets for uncharacterized IclR-family transcription factor YiaJ on the E. coli genome, using gSELEX screening system. Among a total of 18 high-affinity binding targets of YiaJ, the major regulatory target was identified to be the yiaLMNOPQRS operon for utilization of ascorbate from fruits and galacturonate from plant pectin. The targets of YiaJ also include the genes involved in the utilization for other plant-derived materials as nutrients such as fructose, sorbitol, glycerol and fructoselysine. Detailed in vitro and in vivo analyses suggest that L-ascorbate and α-D-galacturonate are the effector ligands for regulation of YiaJ function. These findings altogether indicate that YiaJ plays a major regulatory role in expression of a set of the genes for the utilization of plant-derived materials as nutrients for survival. PlaR was also suggested to play protecting roles of E. coli under stressful environments in nature, including the formation of biofilm. We then propose renaming YiaJ to PlaR (regulator of plant utilization).

scholarly journals Interaction between complement subcomponent C1q and bacterial lipopolysaccharides

1989 ◽  
Vol 257 (3) ◽  
pp. 865-873 ◽  
Author(s):  
A Zohair ◽  
S Chesne ◽  
R H Wade ◽  
M G Colomb
Keyword(s):  
Escherichia Coli ◽  
Chemical Modification ◽  
Essential Role ◽  
Wild Strain ◽  
E Coli ◽  
Diethyl Pyrocarbonate ◽  
Direct Binding ◽  
Bacterial Lipopolysaccharides ◽  
K 12

The heptose-less mutant of Escherichia coli, D31m4, bound complement subcomponent C1q and its collagen-like fragments (C1qCLF) with Ka values of 1.4 x 10(8) and 2.0 x 10(8) M-1 respectively. This binding was suppressed by chemical modification of C1q and C1qCLF using diethyl pyrocarbonate (DEPC). To investigate the role of lipopolysaccharides (LPS) in this binding, biosynthetically labelled [14C]LPS were purified from E. coli D31m4 and incorporated into liposomes prepared from phosphatidylcholine (PC) and phosphatidylethanolamine (PE) [PC/PE/LPS, 2:2:1, by wt.]. Binding of C1q or its collagen-like fragments to the liposomes was estimated via a flotation test. These liposomes bound C1q and C1qCLF with Ka values of 8.0 x 10(7) and 2.0 x 10(7) M-1; this binding was totally inhibited after chemical modification of C1q and C1qCLF by DEPC. Liposomes containing LPS purified from the wild-strain E. coli K-12 S also bound C1q and C1qCLF, whereas direct binding of C1q or C1qCLF to the bacteria was negligible. Diamines at concentrations which dissociate C1 into C1q and (C1r, C1s)2, strongly inhibited the interaction of C1q or C1qCLF with LPS. Removal of 3-deoxy-D-manno-octulosonic acid (2-keto-3-deoxyoctonic acid; KDO) from E. coli D31m4 LPS decreases the binding of C1qCLF to the bacteria by 65%. When this purified and modified LPS was incorporated into liposomes, the C1qCLF binding was completely abolished. These results show: (i) the essential role of the collagen-like moiety and probably its histidine residues in the interaction between C1q and the mutant D31m4; (ii) the contribution of LPS, particularly the anionic charges of KDO, to this interaction.

scholarly journals BaeSR, Involved in Envelope Stress Response, Protects against Lysogenic Conversion by Shiga Toxin 2-Encoding Phages

2015 ◽  
Vol 83 (4) ◽  
pp. 1451-1457 ◽  
Author(s):  
Lejla Imamovic ◽  
Alexandre Martínez-Castillo ◽  
Carmen Benavides ◽  
Maite Muniesa
Keyword(s):  
Stress Responses ◽  
Shiga Toxin ◽  
Phage Infection ◽  
Bacterial Cells ◽  
Content Type ◽  
Signaling Systems ◽  
E Coli ◽  
Envelope Stress ◽  
Lysogenic Conversion

Infection and lysogenic conversion with Shiga toxin-encoding bacteriophages (Stx phages) drive the emergence of new Shiga toxin-producingEscherichia colistrains. Phage attachment to the bacterial surface is the first stage of phage infection. Envelope perturbation causes activation of envelope stress responses in bacterial cells. Although many external factors are known to activate envelope stress responses, the role of these responses in the phage-bacterium interaction remains unexplored. Here, we investigate the link between three envelope signaling systems inE. coli(RcsBC, CpxAR, and BaeSR) and Stx2 phage infection by determining the success of bacterial lysogenic conversion. For this purpose,E. coliDH5α wild-type (WT) and mutant strains lacking RcsBC, CpxAR, or BaeSR signaling systems were incubated with a recombinant Stx2 phage (933W). Notably, the number of lysogens obtained with the BaeSR mutant was 5 log10units higher than with the WT, and the same differences were observed when using 7 different Stx2 phages. To assess whether the membrane receptor used by Stx phages, BamA, was involved in the differences observed,bamAgene expression was monitored by reverse transcription-quantitative PCR (RT-qPCR) in all host strains. A 4-fold-higherbamAexpression level was observed in the BaeSR mutant than in the WT strain, suggesting that differential expression of the receptor used by Stx phages accounted for the increase in the number of lysogenization events. Establishing the link between the role of stress responses and phage infection has important implications for understanding the factors affecting lysogenic conversion, which drives the emergence of new pathogenic clones.

THE INFLUENCE OF THE PO1A1 MUTATION UPON RECOMBINATION IN ESCHERICHIA COLI K12

1979 ◽  
Vol 21 (3) ◽  
pp. 423-428 ◽  
Author(s):  
Barry W. Glickman ◽  
Tineke Rutgers
Keyword(s):  
Escherichia Coli ◽  
Dna Polymerase ◽  
Genetic Recombination ◽  
Dna Polymerase I ◽  
Multiple Gene ◽  
E Coli ◽  
Recombinational Process ◽  
K 12 ◽  
Polymerase I

Genetic recombination in Escherichia coli is a highly regulated process involving multiple gene products. We have investigated the role of DNA polymerase I in this process by studying the effect of the po1A1 mutation upon DNA transfer and conjugation in otherwise isogenic suppressor-free strains of E. coli K-12. It was found that the po1A1 mutation greatly reduces recombination in Hfr crosses (a factor of 20 in Po1+ × Po1A1 crosses and more than a factor of 100 in Po1A1 × Po1A1 crosses). However, since the po1A1 mutation reduces the strains capacity to act as a recipient for an F-prime and the analysis of recombination transfer gradients revealed no differences between Po1+ and Po1− strains, it is concluded that DNA polymerase I probably affects the transfer and/or stability of donor DNA rather than the recombinational process itself.

scholarly journals The Complete Genome Sequence of Escherichia coli phage Eco_BIFF

2018 ◽  
Author(s):  
Lauren Cooper ◽  
Erica Lasek-Nesselquist ◽  
Joseph Wade
Keyword(s):  
Escherichia Coli ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Genome Annotation ◽  
Complete Genome ◽  
Lytic Phage ◽  
E Coli ◽  
K 12 ◽  
Escherichia Coli Phage ◽  
Effective Growth

Escherichia coli phage Eco_BIFF was isolated from several laboratory stocks of E. coli K-12 MG1655 derivatives. The source of the contamination is unknown. Eco_BIFF is a lytic phage that shows effective growth inhibition of E. coli K-12. Here, we announce the complete genome sequence of Eco_BIFF, and major findings from its genome annotation.

scholarly journals HreP, an In Vivo-Expressed Protease of Yersinia enterocolitica, Is a New Member of the Family of Subtilisin/Kexin-Like Proteases

2001 ◽  
Vol 183 (12) ◽  
pp. 3556-3563 ◽  
Author(s):  
Gerhard Heusipp ◽  
Glenn M. Young ◽  
Virginia L. Miller
Keyword(s):  
Yersinia Enterocolitica ◽  
Gene Encoding ◽  
Significant Similarity ◽  
E Coli ◽  
Calcium Dependent ◽  
Autocatalytic Processing ◽  
The Family ◽  
Flagellum Biosynthesis

ABSTRACT The role of proteases in pathogenesis is well established for several microorganisms but has not been described for Yersinia enterocolitica. Previously, we identified a gene,hreP, which showed significant similarity to proteases in a screen for chromosomal genes of Y. enterocoliticathat were exclusively expressed during an infection of mice. We cloned this gene by chromosome capture and subsequently determined its nucleotide sequence. Like inv, the gene encoding the invasin protein of Y. enterocolitica,hreP is located in a cluster of flagellum biosynthesis and chemotaxis genes. The genomic organization of this chromosomal region is different in Escherichia coli, Salmonella, andYersinia pestis than in Y. enterocolitica. Analysis of the distribution ofhreP between different Yersinia isolates and the relatively low G+C content of the gene suggests acquisition by horizontal gene transfer. Sequence analysis also revealed that HreP belongs to a family of eukaryotic subtilisin/kexin-like proteases. Together with the calcium-dependent protease PrcA of Anabaena variabilis, HreP forms a new subfamily of bacterial subtilisin/kexin-like proteases which might have originated from a common eukaryotic ancestor. Like other proteases of this family, HreP is expressed with an N-terminal prosequence. Expression of an HreP-His6 tag fusion protein in E. coli revealed that HreP undergoes autocatalytic processing at a consensus cleavage site of subtilisin/kexin-like proteases, thereby releasing the proprotein.

scholarly journals Variation of the Ribosomal Operon 16S-23S Gene Spacer Region in Representatives of Salmonella enterica Subspecies

1998 ◽  
Vol 180 (8) ◽  
pp. 2144-2151 ◽  
Author(s):  
Sara Pérez Luz ◽  
Francisco Rodríguez-Valera ◽  
Ruiting Lan ◽  
Peter R. Reeves
Keyword(s):  
Salmonella Enterica ◽  
Phylogenetic Trees ◽  
Housekeeping Genes ◽  
The Other ◽  
Nucleotide Substitutions ◽  
E Coli ◽  
The Family ◽  
Ribosomal Operon ◽  
Ribosomal Operons ◽  
K 12

ABSTRACT The 16S-23S spacer regions of two ribosomal operons (rrnA and rrnE) have been sequenced in seven representatives of the Salmonella entericasubspecies. Isolated nucleotide substitutions were found at the same sites as in Escherichia coli but the number of polymorphic sites was much larger, as could be expected for a more heterogeneous species. Still, as in E. coli, most of the variation found was due to insertions and/or deletions affecting blocks of nucleotides generally located at equivalent regions of the putative secondary structure for both species. Isolated polymorphic sites generated phylogenetic trees generally consistent with the subspecies structure and the accepted relationships among the subspecies. However, the sequences of rrnE put subspecies I closer to E. coli K-12 than to the other S. enterica subspecies. The distribution of polymorphisms affecting blocks of nucleotides was much more random, and the presence of equivalent sequences in distantly related subspecies, and even in E. coli, could reflect relatively frequent horizontal transfer. The smallest 16S-23S spacers in other genera of the family Enterobacteriaceaewere also sequenced. As expected, the level of variation was much larger. Still, the phylogenetic tree inferred is consistent with those of 16S rRNA or housekeeping genes.

Sign in / Sign up

Export Citation Format

Share Document