scholarly journals Narrow-Host-Range Bacteriophages That Infect Rhizobium etli Associate with Distinct Genomic Types

2013 ◽  
Vol 80 (2) ◽  
pp. 446-454 ◽  
Author(s):  
Rosa Isela Santamaría ◽  
Patricia Bustos ◽  
Omar Sepúlveda-Robles ◽  
Luis Lozano ◽  
César Rodríguez ◽  
...  
Keyword(s):  
Host Range ◽  
Restriction Enzymes ◽  
Open Reading Frames ◽  
Rhizobium Etli ◽  
Content Type ◽  
Narrow Host Range ◽  
Bean Plants ◽  
Synthesis And Processing ◽  
A Minor

ABSTRACTIn this work, we isolated and characterized 14 bacteriophages that infectRhizobium etli. They were obtained from rhizosphere soil of bean plants from agricultural lands in Mexico using an enrichment method. The host range of these phages was narrow but variable within a collection of 48R. etlistrains. We obtained the complete genome sequence of nine phages. Four phages were resistant to several restriction enzymes andin vivocloning, probably due to nucleotide modifications. The genome size of the sequenced phages varied from 43 kb to 115 kb, with a median size of ∼45 to 50 kb. A large proportion of open reading frames of these phage genomes (65 to 70%) consisted of hypothetical and orphan genes. The remainder encoded proteins needed for phage morphogenesis and DNA synthesis and processing, among other functions, and a minor percentage represented genes of bacterial origin. We classified these phages into four genomic types on the basis of their genomic similarity, gene content, and host range. Since there are no reports of similar sequences, we propose that these bacteriophages correspond to novel species.

scholarly journals A Non-Conserved p33 Protein of Citrus Tristeza Virus Interacts with Multiple Viral Partners

2020 ◽  
Vol 33 (6) ◽  
pp. 859-870 ◽  
Author(s):  
Thi Nguyet Minh Dao ◽  
Sung-Hwan Kang ◽  
Aurélie Bak ◽  
Svetlana Y. Folimonova
Keyword(s):  
Host Range ◽  
Citrus Tristeza Virus ◽  
Protein A ◽  
Integral Membrane Protein ◽  
Open Reading Frames ◽  
Bimolecular Fluorescence Complementation ◽  
In Planta ◽  
Tristeza Virus ◽  
Citrus Tristeza

The RNA genome of citrus tristeza virus (CTV), one of the most damaging viral pathogens of citrus, contains 12 open reading frames resulting in production of at least 19 proteins. Previous studies on the intraviral interactome of CTV revealed self-interaction of the viral RNA-dependent RNA polymerase, the major coat protein (CP), p20, p23, and p33 proteins, while heterologous interactions between the CTV proteins have not been characterized. In this work, we examined interactions between the p33 protein, a nonconserved protein of CTV, which performs multiple functions in the virus infection cycle and is needed for virus ability to infect the extended host range, with other CTV proteins shown to mediate virus interactions with its plant hosts. Using yeast two-hybrid, bimolecular fluorescence complementation, and coimmunoprecipitation assays, we demonstrated that p33 interacts with three viral proteins, i.e., CP, p20, and p23, in vivo and in planta. Coexpression of p33, which is an integral membrane protein, resulted in a shift in the localization of the p20 and p23 proteins toward the subcellular crude-membrane fraction. Upon CTV infection, the four proteins colocalized in the CTV replication factories. In addition, three of them, CP, p20, and p23, were found in the p33-formed membranous structures. Using bioinformatic analyses and mutagenesis, we found that the N-terminus of p33 is involved in the interactions with all three protein partners. A potential role of these interactions in virus ability to infect the extended host range is discussed.

scholarly journals Emergence and Dissemination of Enterobacteriaceae Isolates Producing CTX-M-1-Like Enzymes in Spain Are Associated with IncFII (CTX-M-15) and Broad-Host-Range (CTX-M-1, -3, and -32) Plasmids

2006 ◽  
Vol 51 (2) ◽  
pp. 796-799 ◽  
Author(s):  
Ângela Novais ◽  
Rafael Cantón ◽  
Raquel Moreira ◽  
Luísa Peixe ◽  
Fernando Baquero ◽  
...  
Keyword(s):  
Host Range ◽  
Broad Host Range ◽  
Narrow Host Range

ABSTRACT The spread of CTX-M-1-like enzymes in Spain is associated with particular plasmids of broad-host-range IncN (bla CTX-M-32, bla CTX-M-1), IncL/M (bla CTX-M-1), and IncA/C2 (bla CTX-M-3) or narrow-host-range IncFII (bla CTX-M-15). The identical genetic surroundings of bla CTX-M-32 and bla CTX-M-1 and their locations on related 40-kb IncN plasmids indicate the in vivo evolution of this element.

scholarly journals Mice Expressing Minimally Humanized CD81 and Occludin Genes Support Hepatitis C Virus Uptake In Vivo

2016 ◽  
Vol 91 (4) ◽  
Author(s):  
Qiang Ding ◽  
Markus von Schaewen ◽  
Gabriela Hrebikova ◽  
Brigitte Heller ◽  
Lisa Sandmann ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Host Range ◽  
Amino Acid Sequences ◽  
Host Factors ◽  
Narrow Host Range ◽  
Junction Protein ◽  
Mouse Hepatocytes

ABSTRACT Hepatitis C virus (HCV) causes chronic infections in at least 150 million individuals worldwide. HCV has a narrow host range and robustly infects only humans and chimpanzees. The underlying mechanisms for this narrow host range are incompletely understood. At the level of entry, differences in the amino acid sequences between the human and mouse orthologues of two essential host factors, the tetraspanin CD81 and the tight junction protein occludin (OCLN), explain, at least in part, HCV's limited ability to enter mouse hepatocytes. We have previously shown that adenoviral or transgenic overexpression of human CD81 and OCLN facilitates HCV uptake into mouse hepatocytes in vitro and in vivo. In efforts to refine these models, we constructed knock-in mice in which the second extracellular loops of CD81 and OCLN were replaced with the respective human sequences, which contain the determinants that are critical for HCV uptake. We demonstrate that the humanized CD81 and OCLN were expressed at physiological levels in a tissue-appropriate fashion. Mice bearing the humanized alleles formed normal tight junctions and did not exhibit any immunologic abnormalities, indicating that interactions with their physiological ligands were intact. HCV entry factor knock-in mice take up HCV with an efficiency similar to that in mice expressing HCV entry factors transgenically or adenovirally, demonstrating the utility of this model for studying HCV infection in vivo. IMPORTANCE At least 150 million individuals are chronically infected with hepatitis C virus (HCV). Chronic hepatitis C can result in progressive liver disease and liver cancer. New antiviral treatments can cure HCV in the majority of patients, but a vaccine remains elusive. To gain a better understanding of the processes culminating in liver failure and cancer and to prioritize vaccine candidates more efficiently, small-animal models are needed. Here, we describe the characterization of a new mouse model in which the parts of two host factors that are essential for HCV uptake, CD81 and occludin (OCLN), which differ between mice and humans, were humanized. We demonstrate that such minimally humanized mice develop normally, express the modified genes at physiological levels, and support HCV uptake. This model is of considerable utility for studying viral entry in the three-dimensional context of the liver and to test approaches aimed at preventing HCV entry.

scholarly journals Identification of Bacteriophages for Biocontrol of the Kiwifruit Canker Phytopathogen Pseudomonas syringae pv. actinidiae

2014 ◽  
Vol 80 (7) ◽  
pp. 2216-2228 ◽  
Author(s):  
Rebekah A. Frampton ◽  
Corinda Taylor ◽  
Angela V. Holguín Moreno ◽  
Sandra B. Visnovsky ◽  
Nicola K. Petty ◽  
...  
Keyword(s):  
Host Range ◽  
Pseudomonas Syringae ◽  
Management Strategies ◽  
Pulse Field ◽  
Resistant Bacteria ◽  
Bacterial Canker ◽  
Content Type ◽  
Narrow Host Range ◽  
Pulse Field Gel Electrophoresis ◽  
Isolation And Characterization

ABSTRACTPseudomonas syringaepv. actinidiae is a reemerging pathogen which causes bacterial canker of kiwifruit (Actinidiasp.). Since 2008, a global outbreak ofP. syringaepv. actinidiae has occurred, and in 2010 this pathogen was detected in New Zealand. The economic impact and the development of resistance inP. syringaepv. actinidiae and other pathovars against antibiotics and copper sprays have led to a search for alternative management strategies. We isolated 275 phages, 258 of which were active againstP. syringaepv. actinidiae. Extensive host range testing onP. syringaepv. actinidiae, other pseudomonads, and bacteria isolated from kiwifruit orchards showed that most phages have a narrow host range. Twenty-four were analyzed by electron microscopy, pulse-field gel electrophoresis, and restriction digestion. Their suitability for biocontrol was tested by assessing stability and the absence of lysogeny and transduction. A detailed host range was performed, phage-resistant bacteria were isolated, and resistance to other phages was examined. The phages belonged to theCaudoviralesand were analyzed based on morphology and genome size, which showed them to be representatives ofMyoviridae,Podoviridae, andSiphoviridae. Twenty-oneMyoviridaemembers have similar morphologies and genome sizes yet differ in restriction patterns, host range, and resistance, indicating a closely related group. Nine of theseMyoviridaemembers were sequenced, and each was unique. The most closely related sequenced phages were a group infectingPseudomonas aeruginosaand characterized by phages JG004 and PAK_P1. In summary, this study reports the isolation and characterization ofP. syringaepv. actinidiae phages and provides a framework for the intelligent formulation of phage biocontrol agents against kiwifruit bacterial canker.

scholarly journals Depletion of the Trypanosome Pumilio Domain Protein PUF2 or of Some Other Essential Proteins Causes Transcriptome Changes Related to Coding Region Length

2014 ◽  
Vol 13 (5) ◽  
pp. 664-674 ◽  
Author(s):  
Bhaskar Anand Jha ◽  
Abeer Fadda ◽  
Clementine Merce ◽  
Elisha Mugo ◽  
Dorothea Droll ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Translation ◽  
Open Reading Frames ◽  
Mrna Levels ◽  
Coding Region ◽  
Content Type ◽  
Puf Proteins ◽  
Reading Frames

ABSTRACT Pumilio domain RNA-binding proteins are known mainly as posttranscriptional repressors of gene expression that reduce mRNA translation and stability. Trypanosoma brucei has 11 PUF proteins. We show here that PUF2 is in the cytosol, with roughly the same number of molecules per cell as there are mRNAs. Although PUF2 exhibits a low level of in vivo RNA binding, it is not associated with polysomes. PUF2 also decreased reporter mRNA levels in a tethering assay, consistent with a repressive role. Depletion of PUF2 inhibited growth of bloodstream-form trypanosomes, causing selective loss of mRNAs with long open reading frames and increases in mRNAs with shorter open reading frames. Reexamination of published RNASeq data revealed the same trend in cells depleted of some other proteins. We speculate that these length effects could be caused by inhibition of the elongation phase of transcription or by an influence of translation status or polysomal conformation on mRNA decay.

scholarly journals In Vivo Transfer and Microevolution of Avian Native IncA/C2 blaNDM-1-Carrying Plasmid pRH-1238 during a Broiler Chicken Infection Study

2018 ◽  
Vol 62 (4) ◽  
pp. e02128-17 ◽  
Author(s):  
Sead Hadziabdic ◽  
Jennie Fischer ◽  
Burkhard Malorny ◽  
Maria Borowiak ◽  
Beatriz Guerra ◽  
...  
Keyword(s):  
Host Range ◽  
Broiler Chicken ◽  
Safety Concern ◽  
Fecal Excretion ◽  
Broad Host Range ◽  
Content Type ◽  
Paratyphi B ◽  
Insight Into ◽  
Infection Study

ABSTRACT The emergence and spread of carbapenemase-producing Enterobacteriaceae (CPE) in wildlife and livestock animals pose an important safety concern for public health. With our in vivo broiler chicken infection study, we investigated the transfer and experimental microevolution of the blaNDM-1-carrying IncA/C2 plasmid (pRH-1238) introduced by avian native Salmonella enterica subsp. enterica serovar Corvallis without inducing antibiotic selection pressure. We evaluated the dependency of the time point of inoculation on donor (S. Corvallis [12-SA01738]) and plasmid-free Salmonella recipient [d-tartrate-fermenting (d-Ta+) S. Paratyphi B (13-SA01617), referred to here as S. Paratyphi B (d-Ta+)] excretion by quantifying their excretion dynamics. Using plasmid profiling by S1 nuclease-restricted pulsed-field gel electrophoresis, we gained insight into the variability of the native plasmid content among S. Corvallis reisolates as well as plasmid acquisition in S. Paratyphi B (d-Ta+) and the enterobacterial gut microflora. Whole-genome sequencing enabled us to gain an in-depth insight into the microevolution of plasmid pRH-1238 in S. Corvallis and enterobacterial recipient isolates. Our study revealed that the fecal excretion of avian native carbapenemase-producing S. Corvallis is significantly higher than that of S. Paratyphi (d-Ta+) and is not hampered by S. Paratyphi (d-Ta+). Acquisition of pRH-1238 in other Enterobacteriaceae and several events of plasmid pRH-1238 transfer to different Escherichia coli sequence types and Klebsiella pneumoniae demonstrated an interspecies broad host range. Regardless of the microevolutionary structural deletions in pRH-1238, the single carbapenem resistance marker blaNDM-1 was maintained on pRH-1238 throughout the trial. Furthermore, we showed the importance of the gut E. coli population as a vector of pRH-1238. In a potential scenario of the introduction of NDM-1-producing S. Corvallis into a broiler flock, the pRH-1238 plasmid could persist and spread to a broad host range even in the absence of antibiotic pressure.

scholarly journals Genome Sequence of the Broad-Host-Range Pseudomonas Phage Φ-S1

2012 ◽  
Vol 86 (18) ◽  
pp. 10239-10239 ◽  
Author(s):  
Sanna Sillankorva ◽  
Andrew M. Kropinski ◽  
Joana Azeredo
Keyword(s):  
Host Range ◽  
Genome Sequence ◽  
Open Reading Frames ◽  
Broad Host Range ◽  
Content Type ◽  
Double Stranded Dna ◽  
The Family ◽  
Reading Frames

The broad-host-range lyticPseudomonasphage Φ-S1 possess a 40,192 bp double-stranded DNA (dsDNA) genome of 47 open reading frames (ORFs) and belongs to the familyPodoviridae, subfamilyAutographivirinae, genusT7likevirus.

scholarly journals New Insight into Amphotericin B Resistance in Aspergillus terreus

2013 ◽  
Vol 57 (4) ◽  
pp. 1583-1588 ◽  
Author(s):  
Gerhard Blum ◽  
Caroline Hörtnagl ◽  
Emina Jukic ◽  
Thomas Erbeznik ◽  
Thomas Pümpel ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Molecular Basis ◽  
Aspergillus Terreus ◽  
Minor Role ◽  
Content Type ◽  
Ergosterol Content ◽  
Disseminated Aspergillosis ◽  
A Minor

ABSTRACTAmphotericin B (AMB) is the predominant antifungal drug, but the mechanism of resistance is not well understood. We compared thein vivovirulence of an AMB-resistantAspergillus terreus(ATR) isolate with that of an AMB-susceptibleA. terreusisolate (ATS) using a murine model for disseminated aspergillosis. Furthermore, we analyzed the molecular basis of intrinsic AMB resistancein vitroby comparing the ergosterol content, cell-associated AMB levels, AMB-induced intracellular efflux, and prooxidant effects between ATR and ATS. Infection of immunosuppressed mice with ATS or ATR showed that the ATS strain was more lethal than the ATR strain. However, AMB treatment improved the outcome in ATS-infected mice while having no positive effect on the animals infected with ATR. Thein vitrodata demonstrated that ergosterol content is not the molecular basis for AMB resistance. ATR absorbed less AMB, discharged more intracellular compounds, and had better protection against oxidative damage than the susceptible strain. Our experiments showed that ergosterol content plays a minor role in intrinsic AMB resistance and is not directly associated with intracellular cell-associated AMB content. AMB might exert its antifungal activity by oxidative injury rather than by an increase in membrane permeation.

scholarly journals Evidence of an American Origin for Symbiosis-Related Genes in Rhizobium lusitanum

2011 ◽  
Vol 77 (16) ◽  
pp. 5665-5670 ◽  
Author(s):  
Angel Valverde ◽  
Encarna Velázquez ◽  
Emilio Cervantes ◽  
José M. Igual ◽  
Peter van Berkum
Keyword(s):  
Host Range ◽  
Leucaena Leucocephala ◽  
Sequence Data ◽  
Rapd Analysis ◽  
The Other ◽  
Randomly Amplified Polymorphic Dna ◽  
Nitrogen Fixing ◽  
Chromosomal Dna ◽  
Content Type ◽  
Narrow Host Range

ABSTRACTRandomly amplified polymorphic DNA (RAPD) analysis was used to investigate the diversity of 179 bean isolates recovered from six field sites in the Arcos de Valdevez region of northwestern Portugal. The isolates were divided into 6 groups based on the fingerprint patterns that were obtained. Representatives for each group were selected for sequence analysis of 4 chromosomal DNA regions. Five of the groups were placed withinRhizobium lusitanum, and the other group was placed withinR. tropicitype IIA. Therefore, the collection of Portuguese bean isolates was shown to include the two speciesR. lusitanumandR. tropici. In plant tests, the strains P1-7, P1-1, P1-2, and P1-16 ofR. lusitanumnodulated and formed nitrogen-fixing symbioses both withPhaseolus vulgarisandLeucaena leucocephala. A methyltransferase-encodingnodSgene identical with theR. tropicilocus that confers wide host range was detected in the strain P1-7 as well as 24 others identified asR. lusitanum. A methyltransferase-encodingnodSgene also was detected in the remaining isolates ofR. lusitanum, but in this case the locus was that identified with the narrow-host-rangeR. etli. Representatives of isolates with thenodSofR. etliformed effective nitrogen-fixing symbioses withP. vulgarisand did not nodulateL. leucocephala. From sequence data ofnodS, theR. lusitanumgenes for symbiosis were placed within those of eitherR. tropiciorR. etli. These results would support the suggestion thatR. lusitanumwas the recipient of the genes for symbiosis with beans from bothR. tropiciandR. etli.

scholarly journals Isolation of Polyvalent Bacteriophages by Sequential Multiple-Host Approaches

2015 ◽  
Vol 82 (3) ◽  
pp. 808-815 ◽  
Author(s):  
Pingfeng Yu ◽  
Jacques Mathieu ◽  
Mengyan Li ◽  
Zhaoyi Dai ◽  
Pedro J. J. Alvarez
Keyword(s):  
Host Range ◽  
Pseudomonas Syringae ◽  
Burst Size ◽  
Broad Host Range ◽  
Ecological Significance ◽  
Content Type ◽  
Narrow Host Range ◽  
Isolation Methods ◽  
Culture Independent ◽  
K 12

ABSTRACTMany studies on phage biology are based on isolation methods that may inadvertently select for narrow-host-range phages. Consequently, broad-host-range phages, whose ecological significance is largely unexplored, are consistently overlooked. To enhance research on such polyvalent phages, we developed two sequential multihost isolation methods and tested both culture-dependent and culture-independent phage libraries for broad infectivity. Lytic phages isolated from activated sludge were capable of interspecies or even interorder infectivity without a significant reduction in the efficiency of plating (0.45 to 1.15). Two polyvalent phages (PX1 of thePodoviridaefamily and PEf1 of theSiphoviridaefamily) were characterized in terms of adsorption rate (3.54 × 10−10to 8.53 × 10−10ml/min), latent time (40 to 55 min), and burst size (45 to 99 PFU/cell), using different hosts. These phages were enriched with a nonpathogenic host (Pseudomonas putidaF1 orEscherichia coliK-12) and subsequently used to infect model problematic bacteria. By using a multiplicity of infection of 10 in bacterial challenge tests, >60% lethality was observed forPseudomonas aeruginosarelative to uninfected controls. The corresponding lethality forPseudomonas syringaewas ∼50%. Overall, this work suggests that polyvalent phages may be readily isolated from the environment by using different sequential hosts, and this approach should facilitate the study of their ecological significance as well as enable novel applications.

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