In vitro and in vivo Stability of the 2ζ2 Protein Complex of the Broad Host-Range Streptococcus pyogenes pSM19035 Addiction System

2002 ◽  
Vol 383 (11) ◽  
Author(s):  
A.G. Camacho ◽  
R. Misselwitz ◽  
J. Behlke ◽  
S. Ayora ◽  
K. Welfle ◽  
...  
Keyword(s):  
Host Range ◽  
Streptococcus Pyogenes ◽  
Protein Complex ◽  
Broad Host Range

scholarly journals IncC of Broad-Host-Range Plasmid RK2 Modulates KorB Transcriptional Repressor Activity In Vivo and Operator Binding In Vitro

1999 ◽  
Vol 181 (9) ◽  
pp. 2807-2815 ◽  
Author(s):  
Grazyna Jagura-Burdzy ◽  
Kalliope Kostelidou ◽  
Jessica Pole ◽  
Dheeraj Khare ◽  
Anthony Jones ◽  
...  
Keyword(s):  
Host Range ◽  
Broad Host Range ◽  
Coordinate Regulation ◽  
Broad Host Range Plasmid ◽  
Reporter Systems ◽  
Operator Binding ◽  
Repressor Activity ◽  
Plasmid Rk2

ABSTRACT The korAB operon of broad-host-range plasmid RK2 encodes five genes, two of which, incC andkorB, belong to the parA and parBfamilies, respectively, of genome partitioning functions. BothkorB and a third gene, korA, are responsible for coordinate regulation of operons encoding replication, transfer, and stable inheritance functions. Overexpression of incCalone caused rapid displacement of RK2. Using two different reporter systems, we show that incC modulates the action of KorB. Using promoter fusions to the reporter gene xylE, we show that incC potentiates the repression of transcription bykorB. This modulation of korB activity was only observed with incC1, which encodes the full-length IncC (364 amino acids [aa]), whereas no effect was observed withincC2, which encodes a polypeptide of 259 aa that lacks the N-terminal 105 aa. Using bacterial extracts with IncC1 and IncC2 or IncC1 purified through the use of a His6 tail and Ni-agarose chromatography, we showed that IncC1 potentiates the binding of KorB to DNA at representative KorB operators. The ability of IncC to stabilize KorB-DNA complexes suggests that these two proteins work together in the global regulation of many operons on the IncP-1 genomes, as well in plasmid partitioning.

Conjugative Transfer and in Vitro/in Vivo Stability of the Broad-Host-Range IncP R751 Plasmid in Brucella spp.

Plasmid ◽  
1993 ◽  
Vol 29 (2) ◽  
pp. 142-146 ◽  
Author(s):  
J.M. Verger ◽  
M. Grayon ◽  
E. Chaslus-Dancla ◽  
M. Meurisse ◽  
J.P. Lafont
Keyword(s):  
Host Range ◽  
Broad Host Range ◽  
Conjugative Transfer

In Vivo and in Vitro Stability of the Broad-Host-Range Cloning Vector pBBR1MCS in Six Brucella Species

Plasmid ◽  
1995 ◽  
Vol 33 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Philip H. Elzer ◽  
Michael E. Kovach ◽  
Robert W. Phillips ◽  
Gregory T. Robertson ◽  
Kenneth M. Peterson ◽  
...  
Keyword(s):  
Host Range ◽  
Cloning Vector ◽  
Broad Host Range ◽  
Brucella Species ◽  
In Vitro Stability

scholarly journals Characterization of a Broad-Host-Range Lytic Phage SHWT1 Against Multidrug-Resistant Salmonella and Evaluation of Its Therapeutic Efficacy in vitro and in vivo

2021 ◽  
Vol 8 ◽  
Author(s):  
Chenglin Tao ◽  
Zhengfei Yi ◽  
Yaodong Zhang ◽  
Yao Wang ◽  
Hong Zhu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Host Range ◽  
Therapeutic Efficacy ◽  
Multidrug Resistant ◽  
Lytic Activity ◽  
Resistant Bacteria ◽  
Lytic Phage ◽  
Broad Host Range

Inappropriate use of antibiotics has accelerated to the emergence of multidrug-resistant bacteria, becoming a major health threat. Moreover, bacterial biofilms contribute to antibiotic resistance and prolonged infections. Bacteriophage (phage) therapy may provide an alternative strategy for controlling multidrug-resistant bacterial infections. In this study, a broad-host-range phage, SHWT1, with lytic activity against multidrug-resistant Salmonella was isolated, characterized and evaluated for the therapeutic efficacy in vitro and in vivo. Phage SHWT1 exhibited specific lytic activity against the prevalent Salmonella serovars, such as Salmonella Pullorum, Salmonella Gallinarum, Salmonella Enteritidis, and Salmonella Typhimurium. Morphological analysis showed that phage SHWT1 was a member of the family Siphoviridae and the order Caudovirales. Phage SHWT1 had a latent period of 5 min and burst size of ~150 plaque-forming units (PFUs)/cell. The phage was stable from pH 3-12 and 4–65°C. Phage SHWT1 also showed capacity to lyse Salmonella planktonic cells and inhibit the biofilm formation at optimal multiplicity of infection (MOI) of 0.001, 0.01, 0.1, and 100, respectively. In addition, phage SHWT1 was able to lyse intracellular Salmonella within macrophages. Genome sequencing and phylogenetic analyses revealed that SHWT1 was a lytic phage without toxin genes, virulence genes, antibiotic resistance genes, or significant genomic rearrangements. We found that phage SHWT1 could successfully protect mice against S. enteritidis and S. typhimurium infection. Elucidation of the characteristics and genome sequence of phage SHWT1 demonstrates that this phage is a potential therapeutic agent against the salmonellosis caused by multidrug-resistant Salmonella.

scholarly journals Revealing biophysical properties of KfrA-type proteins as a novel class of cytoskeletal, coiled-coil plasmid-encoded proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Adamczyk ◽  
E. Lewicka ◽  
R. Szatkowska ◽  
H. Nieznanska ◽  
J. Ludwiczak ◽  
...  
Keyword(s):  
Dna Binding ◽  
Host Range ◽  
Coiled Coil ◽  
Amino Acid Sequences ◽  
Broad Host Range ◽  
Biophysical Properties ◽  
Dna Binding Sites ◽  
In Silico Studies ◽  
Wide Range

Abstract Background DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. Results This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1β and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as “threads” by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. Conclusion KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.

scholarly journals The Transcriptional Regulator CpsY Is Important for Innate Immune Evasion in Streptococcus pyogenes

2016 ◽  
Vol 85 (3) ◽  
Author(s):  
Luis A. Vega ◽  
Kayla M. Valdes ◽  
Ganesh S. Sundar ◽  
Ashton T. Belew ◽  
Emrul Islam ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Immune Evasion ◽  
Immune Cell ◽  
Group A Streptococcus ◽  
Transcriptional Regulator ◽  
Innate Immune ◽  
Content Type ◽  
Human Host

ABSTRACTAs an exclusively human pathogen,Streptococcus pyogenes(the group A streptococcus [GAS]) has specifically adapted to evade host innate immunity and survive in multiple tissue niches, including blood. GAS can overcome the metabolic constraints of the blood environment and expresses various immunomodulatory factors necessary for survival and immune cell resistance. Here we present our investigation of one such factor, the predicted LysR family transcriptional regulator CpsY. The encoding gene,cpsY, was initially identified as being required for GAS survival in a transposon-site hybridization (TraSH) screen in whole human blood. CpsY is homologous with transcriptional regulators ofStreptococcus mutans(MetR),Streptococcus iniae(CpsY), andStreptococcus agalactiae(MtaR) that regulate methionine transport, amino acid metabolism, resistance to neutrophil-mediated killing, and survivalin vivo. Our investigation indicated that CpsY is involved in GAS resistance to innate immune cells of its human host. However, GAS CpsY does not manifest thein vitrophenotypes of its homologs in other streptococcal species. GAS CpsY appears to regulate a small set of genes that is markedly different from the regulons of its homologs. The differential expression of these genes depends on the growth medium, and CpsY modestly influences their expression. The GAS CpsY regulon includes known virulence factors (mntE,speB,spd,nga[spn],prtS[SpyCEP], andsse) and cell surface-associated factors of GAS (emm1,mur1.2,sibA[cdhA], andM5005_Spy0500). Intriguingly, the loss of CpsY in GAS does not result in virulence defects in murine models of infection, suggesting that CpsY function in immune evasion is specific to the human host.

scholarly journals Glycoprotein D-Independent Infectivity of Pseudorabies Virus Results in an Alteration of In Vivo Host Range and Correlates with Mutations in Glycoproteins B and H

2001 ◽  
Vol 75 (21) ◽  
pp. 10054-10064 ◽  
Author(s):  
Jerg Schmidt ◽  
Volker Gerdts ◽  
Jörg Beyer ◽  
Barbara G. Klupp ◽  
Thomas C. Mettenleiter
Keyword(s):  
Host Range ◽  
Pseudorabies Virus ◽  
Natural Host ◽  
Target Cells ◽  
Glycoprotein D ◽  
Wild Type ◽  
Cellular Receptors ◽  
Receptor Usage

ABSTRACT Infection of cells by herpesviruses is initiated by the interaction of viral envelope glycoproteins with cellular receptors. In the alphaherpesvirus pseudorabies virus (PrV), the causative agent of Aujeszky's disease in pigs, the essential glycoprotein D (gD) mediates secondary attachment of virions to target cells by binding to newly identified cellular receptors (R. J. Geraghty, C. Krummenacher, G. H. Cohen, R. J. Eisenberg, and P. G. Spear, Science 280:1618–1620, 1998). However, in the presence of compensatory mutations, infection can also occur in the absence of gD, as evidenced by the isolation in cell culture of an infectious gD-negative PrV mutant (PrV-gD− Pass) (J. Schmidt, B. G. Klupp, A. Karger, and T. C. Mettenleiter, J. Virol. 71:17–24, 1997). PrV-gD− Pass is replication competent with an only moderate reduction in specific infectivity but appears to bind to receptors different from those recognized by wild-type PrV (A. Karger, J. Schmidt, and T. C. Mettenleiter, J. Virol. 72:7341–7348, 1998). To analyze whether this alteration in receptor usage in vitro influences infection in vivo, the model host mouse and the natural host pig were intranasally infected with PrV-gD− Pass and were compared to animals infected by wild-type PrV. For mice, a comparable progress of disease was observed, and all animals infected with mutant virus died, although they exhibited a slight delay in the onset of symptoms and, correspondingly, a longer time to death. In contrast, whereas wild-type PrV-infected pigs showed clinical signs and histological and histopathological findings typical of PrV infection, no signs of disease were observed after infection with PrV-gD− Pass. Moreover, in these animals, virus-infected cells were not detectable by immunohistochemical staining of different organ samples and no virus could be isolated from nasal swabs. Mutations in glycoproteins B and H were found to correlate with, and probably contribute to, gD-independent infectivity. In conclusion, although PrV-gD− Pass is virulent in mice, it is apparently unable to infect the natural host, the pig. This altered host range in vivo correlates with a difference of receptor usage in vitro and demonstrates for the first time the importance of gD receptors in alphaherpesvirus infection of an animal host.

IN VITRO AND IN VIVO PROPERTIES OF AN INFLUENZA A HOST RANGE VIRUS

1984 ◽  
pp. 379-386
Author(s):  
Dan C. DeBorde ◽  
Armen M. Donabedian ◽  
Susan M. Peters ◽  
H.F. Maassab
Keyword(s):  
Host Range ◽  
Influenza A
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