scholarly journals Genome Variation and Molecular Epidemiology ofSalmonella entericaSerovar Typhimurium Pathovariants

2018 ◽  
Vol 86 (8) ◽  
Author(s):  
Priscilla Branchu ◽  
Matt Bawn ◽  
Robert A. Kingsley
Keyword(s):  
Molecular Epidemiology ◽  
Host Range ◽  
Animal Health ◽  
Wide Distribution ◽  
Genomic Diversity ◽  
Broad Host Range ◽  
Wild Animals ◽  
Genome Variation ◽  
Content Type ◽  
The Impact

ABSTRACTSalmonella entericaserovar Typhimurium is one of approximately 2,500 distinct serovars of the genusSalmonellabut is exceptional in its wide distribution in the environment, livestock, and wild animals.S. Typhimurium causes a large proportion of nontyphoidalSalmonella(NTS) infections, accounting for a quarter of infections, second only toS. entericaserovar Enteritidis in incidence.S. Typhimurium was once considered the archetypal broad-host-rangeSalmonellaserovar due to its wide distribution in livestock and wild animals, and much of what we know of the interaction ofSalmonellawith the host comes from research using a small number of laboratory strains of the serovar (LT2, SL1344, and ATCC 14028). But it has become clear that these strains do not reflect the genotypic or phenotypic diversity ofS. Typhimurium. Here, we review the epidemiological record ofS. Typhimurium and studies of the host-pathogen interactions of diverse strains ofS. Typhimurium. We present the concept of distinct pathovariants ofS. Typhimurium that exhibit diversity of host range, distribution in the environment, pathogenicity, and risk to food safety. We review recent evidence from whole-genome sequencing that has revealed the extent of genomic diversity ofS. Typhimurium pathovariants, the genomic basis of differences in the level of risk to human and animal health, and the molecular epidemiology of prominent strains. An improved understanding of the impact of genome variation of bacterial pathogens on pathogen-host and pathogen-environment interactions has the potential to improve quantitative risk assessment and reveal how new pathogens evolve.

scholarly journals Silage Collected from Dairy Farms Harbors an Abundance of Listeriaphages with Considerable Host Range and Genome Size Diversity

2012 ◽  
Vol 78 (24) ◽  
pp. 8666-8675 ◽  
Author(s):  
Kitiya Vongkamjan ◽  
Andrea Moreno Switt ◽  
Henk C. den Bakker ◽  
Esther D. Fortes ◽  
Martin Wiedmann
Keyword(s):  
Host Range ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Genomic Diversity ◽  
Broad Host Range ◽  
Content Type ◽  
Narrow Host Range ◽  
Food Borne ◽  
Size Diversity ◽  
Range Characterization

ABSTRACTSince the food-borne pathogenListeria monocytogenesis common in dairy farm environments, it is likely that phages infecting this bacterium (“listeriaphages”) are abundant on dairy farms. To better understand the ecology and diversity of listeriaphages on dairy farms and to develop a diverse phage collection for further studies, silage samples collected on two dairy farms were screened forL. monocytogenesand listeriaphages. While only 4.5% of silage samples tested positive forL. monocytogenes, 47.8% of samples were positive for listeriaphages, containing up to >1.5 × 104PFU/g. Host range characterization of the 114 phage isolates obtained, with a reference set of 13L. monocytogenesstrains representing the nine major serotypes and four lineages, revealed considerable host range diversity; phage isolates were classified into nine lysis groups. While one serotype 3c strain was not lysed by any phage isolates, serotype 4 strains were highly susceptible to phages and were lysed by 63.2 to 88.6% of phages tested. Overall, 12.3% of phage isolates showed a narrow host range (lysing 1 to 5 strains), while 28.9% of phages represented broad host range (lysing ≥11 strains). Genome sizes of the phage isolates were estimated to range from approximately 26 to 140 kb. The extensive host range and genomic diversity of phages observed here suggest an important role of phages in the ecology ofL. monocytogeneson dairy farms. In addition, the phage collection developed here has the potential to facilitate further development of phage-based biocontrol strategies (e.g., in silage) and other phage-based tools.

scholarly journals In VivoTransmission of an IncA/C Plasmid in Escherichia coli Depends on Tetracycline Concentration, and Acquisition of the Plasmid Results in a Variable Cost of Fitness

2015 ◽  
Vol 81 (10) ◽  
pp. 3561-3570 ◽  
Author(s):  
Timothy J. Johnson ◽  
Randall S. Singer ◽  
Richard E. Isaacson ◽  
Jessica L. Danzeisen ◽  
Kevin Lang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Dose ◽  
Broad Host Range ◽  
Antibiotic Administration ◽  
Dose Administration ◽  
Content Type ◽  
E Coli ◽  
The Impact ◽  
Selection Of

ABSTRACTIncA/C plasmids are broad-host-range plasmids enabling multidrug resistance that have emerged worldwide among bacterial pathogens of humans and animals. Although antibiotic usage is suspected to be a driving force in the emergence of such strains, few studies have examined the impact of different types of antibiotic administration on the selection of plasmid-containing multidrug resistant isolates. In this study, chlortetracycline treatment at different concentrations in pig feed was examined for its impact on selection and dissemination of an IncA/C plasmid introduced orally via a commensalEscherichia colihost. Continuous low-dose administration of chlortetracycline at 50 g per ton had no observable impact on the proportions of IncA/C plasmid-containingE. colifrom pig feces over the course of 35 days. In contrast, high-dose administration of chlortetracycline at 350 g per ton significantly increased IncA/C plasmid-containingE. coliin pig feces (P< 0.001) and increased movement of the IncA/C plasmid to other indigenousE. colihosts. There was no evidence of conjugal transfer of the IncA/C plasmid to bacterial species other thanE. coli.In vitrocompetition assays demonstrated that bacterial host background substantially impacted the cost of IncA/C plasmid carriage inE. coliandSalmonella.In vitrotransfer and selection experiments demonstrated that tetracycline at 32 μg/ml was necessary to enhance IncA/C plasmid conjugative transfer, while subinhibitory concentrations of tetracyclinein vitrostrongly selected for IncA/C plasmid-containingE. coli. Together, these experiments improve our knowledge on the impact of differing concentrations of tetracycline on the selection of IncA/C-type plasmids.

scholarly journals Evolution of IncA/CblaCMY-2-Carrying Plasmids by Acquisition of theblaNDM-1Carbapenemase Gene

2011 ◽  
Vol 56 (2) ◽  
pp. 783-786 ◽  
Author(s):  
Alessandra Carattoli ◽  
Laura Villa ◽  
Laurent Poirel ◽  
Rémy A. Bonnin ◽  
Patrice Nordmann
Keyword(s):  
Host Range ◽  
Large Scale ◽  
The United States ◽  
Broad Host Range ◽  
New Delhi ◽  
Yersinia Ruckeri ◽  
Content Type ◽  
Photobacterium Damselae ◽  
Environmental Bacteria ◽  
Broad Host Range Plasmids

ABSTRACTTheblaNDM-1gene has been reported to be often located on broad-host-range plasmids of the IncA/C type in clinical but also environmental bacteria recovered from the New Delhi, India, area. IncA/C-type plasmids are the main vehicles for the spread of the cephalosporinase geneblaCMY-2, frequently identified in the United States, Canada, and Europe. In this study, we completed the sequence of IncA/C plasmid pNDM-KN carrying theblaNDM-1gene, recovered from aKlebsiella pneumoniaeisolate from Kenya. This sequence was compared with those of three IncA/C-type reference plasmids fromEscherichia coli,Yersinia ruckeri, andPhotobacterium damselae. Comparative analysis showed that theblaNDM-1gene was located on a widely diffused plasmid scaffold known to be responsible for the spread ofblaCMY-2-like genes and consequently for resistance to broad-spectrum cephalosporins. Considering that IncA/C plasmids possess a broad host range, this scaffold might support a large-scale diffusion of theblaNDM-1gene among Gram-negative rods.

scholarly journals A Multispecies Cluster of VIM-1 Carbapenemase-Producing Enterobacterales Linked by a Novel, Highly Conjugative, and Broad-Host-Range IncA Plasmid Forebodes the Reemergence of VIM-1

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Gabriele Arcari ◽  
Federica Maria Di Lella ◽  
Giulia Bibbolino ◽  
Fabio Mengoni ◽  
Marzia Beccaccioli ◽  
...  
Keyword(s):  
Host Range ◽  
Bacterial Species ◽  
Klebsiella Oxytoca ◽  
Gene Cassette ◽  
University Hospital ◽  
Broad Host Range ◽  
Class 1 Integron ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Class 1

ABSTRACT In this study, we investigated VIM-1-producing Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Citrobacter freundii, and Enterobacter cloacae strains, isolated in 2019 during a period of active surveillance of carbapenem-resistant Enterobacterales in a large university hospital in Italy. VIM-1-producing strains colonized the gut of patients, with up to three different VIM-1-positive bacterial species isolated from a single rectal swab, but also caused bloodstream infection in one colonized patient. In the multispecies cluster, blaVIM-1 was identified in a 5-gene cassette class 1 integron, associated with several genetic determinants, including the blaSHV-12, qnrS1, and mph(A) genes, located on a highly conjugative and broad-host-range IncA plasmid. The characteristics and origin of this IncA plasmid were studied.

scholarly journals Mutant and Recombinant Phages Selected from In Vitro Coevolution Conditions Overcome Phage-Resistant Listeria monocytogenes

2020 ◽  
Vol 86 (22) ◽  
Author(s):  
Tracey Lee Peters ◽  
Yaxiong Song ◽  
Daniel W. Bryan ◽  
Lauren K. Hudson ◽  
Thomas G. Denes
Keyword(s):  
Listeria Monocytogenes ◽  
Host Range ◽  
Foodborne Pathogen ◽  
Resistant Bacteria ◽  
Phage Resistance ◽  
Short Term ◽  
Content Type ◽  
Life Threatening ◽  
The Impact

ABSTRACT Bacteriophages (phages) are currently available for use by the food industry to control the foodborne pathogen Listeria monocytogenes. Although phage biocontrols are effective under specific conditions, their use can select for phage-resistant bacteria that repopulate phage-treated environments. Here, we performed short-term coevolution experiments to investigate the impact of single phages and a two-phage cocktail on the regrowth of phage-resistant L. monocytogenes and the adaptation of the phages to overcome this resistance. We used whole-genome sequencing to identify mutations in the target host that confer phage resistance and in the phages that alter host range. We found that infections with Listeria phages LP-048, LP-125, or a combination of both select for different populations of phage-resistant L. monocytogenes bacteria with different regrowth times. Phages isolated from the end of the coevolution experiments were found to have gained the ability to infect phage-resistant mutants of L. monocytogenes and L. monocytogenes strains previously found to be broadly resistant to phage infection. Phages isolated from coinfected cultures were identified as recombinants of LP-048 and LP-125. Interestingly, recombination events occurred twice independently in a locus encoding two proteins putatively involved in DNA binding. We show that short-term coevolution of phages and their hosts can be utilized to obtain mutant and recombinant phages with adapted host ranges. These laboratory-evolved phages may be useful for limiting the emergence of phage resistance and for targeting strains that show general resistance to wild-type (WT) phages. IMPORTANCE Listeria monocytogenes is a life-threatening bacterial foodborne pathogen that can persist in food processing facilities for years. Phages can be used to control L. monocytogenes in food production, but phage-resistant bacterial subpopulations can regrow in phage-treated environments. Coevolution experiments were conducted on a Listeria phage-host system to provide insight into the genetic variation that emerges in both the phage and bacterial host under reciprocal selective pressure. As expected, mutations were identified in both phage and host, but additionally, recombination events were shown to have repeatedly occurred between closely related phages that coinfected L. monocytogenes. This study demonstrates that in vitro evolution of phages can be utilized to expand the host range and improve the long-term efficacy of phage-based control of L. monocytogenes. This approach may also be applied to other phage-host systems for applications in biocontrol, detection, and phage therapy.

scholarly journals Genome Characterization, Prevalence, and Transmission Mode of a Novel Picornavirus Associated with the Threespine Stickleback Fish (Gasterosteus aculeatus)

2019 ◽  
Vol 93 (9) ◽  
Author(s):  
Megan A. Hahn ◽  
Nolwenn M. Dheilly
Keyword(s):  
Gasterosteus Aculeatus ◽  
Rna Virus ◽  
Wide Distribution ◽  
Model System ◽  
Threespine Stickleback ◽  
Tissue Samples ◽  
Content Type ◽  
Threespine Sticklebacks ◽  
The Impact

ABSTRACT The complete genome sequence of an RNA virus was assembled from RNA sequencing of virus particles purified from threespine stickleback intestine tissue samples. This new virus is most closely related to the Eel picornavirus and can be assigned to the genus Potamipivirus in the family Picornaviridae. Its unique genetic properties are enough to establish a new species, dubbed the Threespine Stickleback picornavirus (TSPV). Due to their broad geographic distribution throughout the Northern Hemisphere and parallel adaptation to freshwater, threespine sticklebacks have become a model in evolutionary ecology. Further analysis using diagnostic PCRs revealed that TSPV is highly prevalent in both anadromous and freshwater populations of threespine sticklebacks, infects almost all fish tissues, and is transmitted vertically to offspring obtained from in vitro fertilization in laboratory settings. Finally, TSPV was found in Sequence Reads Archives of transcriptome of Gasterosteus aculeatus, further demonstrating its wide distribution and unsought prevalence in samples. It is thus necessary to test the impact of TSPV on the biology of threespine sticklebacks, as this widespread virus could interfere with the behavioral, physiological, or immunological studies that employ this fish as a model system. IMPORTANCE The threespine stickleback species complex is an important model system in ecological and evolutionary studies because of the large number of isolated divergent populations that are experimentally tractable. For similar reasons, its coevolution with the cestode parasite Schistocephalus solidus, its interaction with gut microbes, and the evolution of its immune system are of growing interest. Herein we describe the discovery of an RNA virus that infects both freshwater and anadromous populations of sticklebacks. We show that the virus is transmitted vertically in laboratory settings and found it in Sequence Reads Archives, suggesting that experiments using sticklebacks were conducted in the presence of the virus. This discovery can serve as a reminder that the presence of viruses in wild-caught animals is possible, even when animals appear healthy. Regarding threespine sticklebacks, the impact of Threespine Stickleback picornavirus (TSPV) on the fish biology should be investigated further to ensure that it does not interfere with experimental results.

scholarly journals Construction of a Broad-Host-Range Tn7-Based Vector for Single-Copy PBAD-Controlled Gene Expression in Gram-Negative Bacteria

2012 ◽  
Vol 79 (2) ◽  
pp. 718-721 ◽  
Author(s):  
F. Heath Damron ◽  
Elizabeth S. McKenney ◽  
Herbert P. Schweizer ◽  
Joanna B. Goldberg
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Host Range ◽  
Single Copy ◽  
Broad Host Range ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Delivery Vector ◽  
Inducible Gene

ABSTRACTWe describe a mini-Tn7-based broad-host-range expression cassette for arabinose-inducible gene expression from the PBADpromoter. This delivery vector, pTJ1, can integrate a single copy of a gene into the chromosome of Gram-negative bacteria for diverse genetic applications, of which several are discussed, usingPseudomonas aeruginosaas the model host.

scholarly journals The Sinorhizobium (Ensifer) fredii HH103 Nodulation Outer Protein NopI Is a Determinant for Efficient Nodulation of Soybean and Cowpea Plants

2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Irene Jiménez-Guerrero ◽  
Francisco Pérez-Montaño ◽  
Carlos Medina ◽  
Francisco Javier Ollero ◽  
Francisco Javier López-Baena
Keyword(s):  
Adenylate Cyclase ◽  
Host Cell ◽  
Host Range ◽  
Pathogenic Bacteria ◽  
Defense Responses ◽  
Host Cells ◽  
Broad Host Range ◽  
Sinorhizobium Fredii ◽  
Symbiotic Efficiency ◽  
Content Type

ABSTRACT The type III secretion system (T3SS) is a specialized secretion apparatus that is commonly used by many plant and animal pathogenic bacteria to deliver proteins, termed effectors, to the interior of the host cells. These effectors suppress host defenses and interfere with signal transduction pathways to promote infection. Some rhizobial strains possess a functional T3SS, which is involved in the suppression of host defense responses, host range determination, and symbiotic efficiency. The analysis of the genome of the broad-host-range rhizobial strain Sinorhizobium fredii HH103 identified eight genes that code for putative T3SS effectors. Three of these effectors, NopL, NopP, and NopI, are Rhizobium specific. In this work, we demonstrate that NopI, whose amino acid sequence shows a certain similarity with NopP, is secreted through the S. fredii HH103 T3SS in response to flavonoids. We also determined that NopL can be considered an effector since it is directly secreted to the interior of the host cell as demonstrated by adenylate cyclase assays. Finally, the symbiotic phenotype of single, double, and triple nopI, nopL, and nopP mutants in soybean and cowpea was assayed, showing that NopI plays an important role in determining the number of nodules formed in both legumes and that the absence of both NopL and NopP is highly detrimental for symbiosis. IMPORTANCE The paper is focused on three Rhizobium-specific T3SS effectors of Sinorhizobium fredii HH103, NopL, NopP, and NopI. We demonstrate that S. fredii HH103 is able to secrete through the T3SS in response to flavonoids the nodulation outer protein NopI. Additionally, we determined that NopL can be considered an effector since it is secreted to the interior of the host cell as demonstrated by adenylate cyclase assays. Finally, nodulation assays of soybean and cowpea indicated that NopI is important for the determination of the number of nodules formed and that the absence of both NopL and NopP negatively affected nodulation.

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.

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