scholarly journals Bacteria-mediated stabilization of a panel of Picornaviruses

2018 ◽  
Author(s):  
Elizabeth R. Aguilera ◽  
Y Nguyen ◽  
Jun Sasaki ◽  
Julie K. Pfeiffer
Keyword(s):  
Thermal Stability ◽  
Bacterial Species ◽  
Enteric Virus ◽  
Aichi Virus ◽  
Bacterial Strains ◽  
Bacterial Surface ◽  
Oral Transmission ◽  
Specific Effects ◽  
Surface Polysaccharides ◽  
Mengo Virus

ABSTRACTSeveral viruses encounter various bacterial species within the host and in the environment. Despite these close encounters, the effects of bacteria on picornaviruses specifically is not completely understood. Previous work determined that poliovirus (PV), an enteric virus, has enhanced virion stability when exposed to bacteria or bacterial surface polysaccharides such as lipopolysaccharide. Virion stabilization by bacteria may be important for inter-host transmission since a mutant PV with reduced bacterial binding had a fecal-oral transmission defect in mice. Therefore, we investigated whether bacteria broadly enhance stability of picornaviruses from three different genera: Enterovirus (PV and coxsackievirus B3 (CVB3)), Kobuvirus (Aichi virus) and Cardiovirus (Mengo virus). Furthermore, to delineate strain-specific effects, we examined two strains of CVB3 and a PV mutant with enhanced thermal stability. We determined that specific bacterial strains enhance thermal stability of PV and CVB3, while Mengo virus and Aichi virus are stable at high temperatures in the absence of bacteria. Additionally, we determined that bacteria or lipopolysaccharide can stabilize PV, CVB3, Aichi virus, and Mengo virus during exposure to bleach. These effects are likely mediated through direct interactions with bacteria since viruses bound to bacteria in a pull-down assay. Overall, this work reveals shared and distinct effects of bacteria on a panel of picornaviruses.IMPORTANCERecent studies have shown that bacteria promote infection and stabilization of poliovirus particles, but the breadth of these effects on other members of the Picornaviridae family is unknown. Here, we compared the effect of bacteria on four distinct members of the Picornaviridae family. We found that bacteria reduced inactivation of all of the viruses during bleach treatment, but not all viral strains were stabilized by bacteria during heat treatment. Overall, our data provide insight into how bacteria play differential roles on picornavirus stability.

scholarly journals Bacterial Stabilization of a Panel of Picornaviruses

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Elizabeth R. Aguilera ◽  
Y Nguyen ◽  
Jun Sasaki ◽  
Julie K. Pfeiffer
Keyword(s):  
Thermal Stability ◽  
Bacterial Species ◽  
Enteric Virus ◽  
Aichi Virus ◽  
Bacterial Strains ◽  
Bacterial Surface ◽  
Oral Transmission ◽  
Specific Effects ◽  
Pulldown Assay ◽  
Surface Polysaccharides

ABSTRACTSeveral viruses encounter various bacterial species within the host and in the environment. Despite these close encounters, the effects of bacteria on picornaviruses are not completely understood. Previous work determined that poliovirus (PV), an enteric virus, has enhanced virion stability when exposed to bacteria or bacterial surface polysaccharides such as lipopolysaccharide. Virion stabilization by bacteria may be important for interhost transmission, since a mutant PV with reduced bacterial binding had a fecal-oral transmission defect in mice. Therefore, we investigated whether bacteria broadly enhance stability of picornaviruses from three different genera:Enterovirus(PV and coxsackievirus B3 [CVB3]),Kobuvirus(Aichi virus), andCardiovirus(mengovirus). Furthermore, to delineate strain-specific effects, we examined two strains of CVB3 and a PV mutant with enhanced thermal stability. We determined that specific bacterial strains enhance thermal stability of PV and CVB3, while mengovirus and Aichi virus are stable at high temperatures in the absence of bacteria. Additionally, we determined that bacteria or lipopolysaccharide can stabilize PV, CVB3, Aichi virus, and mengovirus during exposure to bleach. These effects are likely mediated through direct interactions with bacteria, since viruses bound to bacteria in a pulldown assay. Overall, this work reveals shared and distinct effects of bacteria on a panel of picornaviruses.IMPORTANCERecent studies have shown that bacteria promote infection and stabilization of poliovirus particles, but the breadth of these effects on other members of thePicornaviridaefamily is unknown. Here, we compared the effects of bacteria on four distinct members of thePicornaviridaefamily. We found that bacteria reduced inactivation of all of the viruses during bleach treatment, but not all viral strains were stabilized by bacteria during heat treatment. Overall, our data provide insight into how bacteria play differential roles in picornavirus stability.

scholarly journals The Conservation of Low Complexity Regions in Bacterial Proteins Depends on the Pathogenicity of the Strain and Subcellular Location of the Protein

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 451
Author(s):  
Pablo Mier ◽  
Miguel A. Andrade-Navarro
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Bacterial Species ◽  
Outer Membrane Proteins ◽  
Subcellular Location ◽  
Low Complexity ◽  
Extracellular Proteins ◽  
Bacterial Strains ◽  
Bacterial Proteins ◽  
Protein Subcellular Location

Low complexity regions (LCRs) in proteins are characterized by amino acid frequencies that differ from the average. These regions evolve faster and tend to be less conserved between homologs than globular domains. They are not common in bacteria, as compared to their prevalence in eukaryotes. Studying their conservation could help provide hypotheses about their function. To obtain the appropriate evolutionary focus for this rapidly evolving feature, here we study the conservation of LCRs in bacterial strains and compare their high variability to the closeness of the strains. For this, we selected 20 taxonomically diverse bacterial species and obtained the completely sequenced proteomes of two strains per species. We calculated all orthologous pairs for each of the 20 strain pairs. Per orthologous pair, we computed the conservation of two types of LCRs: compositionally biased regions (CBRs) and homorepeats (polyX). Our results show that, in bacteria, Q-rich CBRs are the most conserved, while A-rich CBRs and polyA are the most variable. LCRs have generally higher conservation when comparing pathogenic strains. However, this result depends on protein subcellular location: LCRs accumulate in extracellular and outer membrane proteins, with conservation increased in the extracellular proteins of pathogens, and decreased for polyX in the outer membrane proteins of pathogens. We conclude that these dependencies support the functional importance of LCRs in host–pathogen interactions.

scholarly journals Isolation and efficacy of two bacterial strains antagonists of Erwinia amylovora and Pectobacterium carotovorum

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
M’hamed BENADA ◽  
Boualem BOUMAAZA ◽  
Sofiane BOUDALIA ◽  
Omar KHALADI
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Bacterial Species ◽  
Crop Protection ◽  
Soft Rot ◽  
Causal Agent ◽  
Plant Diseases ◽  
Ecological Niches ◽  
Pectobacterium Carotovorum ◽  
Bacterial Strains

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.

In vitro evaluation of the effect of nicotine, cotinine, and caffeine on oral microorganisms

2008 ◽  
Vol 54 (6) ◽  
pp. 501-508 ◽  
Author(s):  
Karina Cogo ◽  
Michelle Franz Montan ◽  
Cristiane de Cássia Bergamaschi ◽  
Eduardo D. Andrade ◽  
Pedro Luiz Rosalen ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Culture Media ◽  
Bacterial Species ◽  
In Vitro Study ◽  
Bacterial Strains ◽  
Planktonic Cells ◽  
Susceptibility Tests

The aim of this in vitro study was to evaluate the effects of nicotine, cotinine, and caffeine on the viability of some oral bacterial species. It also evaluated the ability of these bacteria to metabolize those substances. Single-species biofilms of Streptococcus gordonii , Porphyromonas gingivalis , or Fusobacterium nucleatum and dual-species biofilms of S. gordonii – F. nucleatum and F. nucleatum – P. gingivalis were grown on hydroxyapatite discs. Seven species were studied as planktonic cells, including Streptococcus oralis , Streptococcus mitis , Propionibacterium acnes , Actinomyces naeslundii , and the species mentioned above. The viability of planktonic cells and biofilms was analyzed by susceptibility tests and time-kill assays, respectively, against different concentrations of nicotine, cotinine, and caffeine. High-performance liquid chromatography was performed to quantify nicotine, cotinine, and caffeine concentrations in the culture media after the assays. Susceptibility tests and viability assays showed that nicotine, cotinine, and caffeine cannot reduce or stimulate bacterial growth. High-performance liquid chromatography results showed that nicotine, cotinine, and caffeine concentrations were not altered after bacteria exposure. These findings indicate that nicotine, cotinine, and caffeine, in the concentrations used, cannot affect significantly the growth of these oral bacterial strains. Moreover, these species do not seem to metabolize these substances.

scholarly journals Identification and Characterization of a Poliovirus Capsid Mutant with Enhanced Thermal Stability

2018 ◽  
Vol 93 (6) ◽  
Author(s):  
Y Nguyen ◽  
Palmy R. Jesudhasan ◽  
Elizabeth R. Aguilera ◽  
Julie K. Pfeiffer
Keyword(s):  
Thermal Stability ◽  
High Temperatures ◽  
Oral Route ◽  
Mutant Virus ◽  
Single Amino Acid ◽  
Bacterial Surface ◽  
Virus Particles ◽  
Heat Resistant ◽  
Viral Particles ◽  
Very High

ABSTRACTEnteric viruses, including poliovirus, are spread by the fecal-oral route. In order to persist and transmit to a new host, enteric virus particles must remain stable once they are in the environment. Environmental stressors such as heat and disinfectants can inactivate virus particles and prevent viral transmission. It has been previously demonstrated that bacteria or bacterial surface glycans can enhance poliovirus virion stability and limit inactivation from heat or bleach. While investigating the mechanisms underlying bacterially enhanced virion thermal stability, we identified and characterized a poliovirus (PV) mutant with increased resistance to heat inactivation. The M132V mutant harbors a single amino acid change in the VP1 capsid coding that is sufficient to confer heat resistance but not bleach resistance. Although the M132V virus was stable in the absence of bacteria or feces at most temperatures, M132V virus was stabilized by feces at very high temperatures. M132V PV had reduced specific infectivity and RNA uncoating compared with those of wild-type (WT) PV, but viral yields in HeLa cells were similar. In orally inoculated mice, M132V had a slight fitness cost since fecal titers were lower and 12.5% of fecal viruses reverted to the WT. Overall, this work sheds light on factors that influence virion stability and fitness.IMPORTANCEViruses spread by the fecal-oral route need to maintain viability in the environment to ensure transmission. Previous work indicated that bacteria and bacterial surface polysaccharides can stabilize viral particles and enhance transmission. To explore factors that influence viral particle stability, we isolated a mutant poliovirus that is heat resistant. This mutant virus does not require feces for stability at most temperatures but can be stabilized by feces at very high temperatures. Even though the mutant virus is heat resistant, it is susceptible to inactivation by treatment with bleach. This work provides insight into how viral particles maintain infectivity in the environment.

scholarly journals Diversity and evolution of surface polysaccharide synthesis loci in Enterobacteriales

2019 ◽  
Author(s):  
Kathryn E. Holt ◽  
Florent Lassalle ◽  
Kelly L. Wyres ◽  
Ryan Wick ◽  
Rafal J. Mostowy
Keyword(s):  
Evolutionary Dynamics ◽  
Bacterial Species ◽  
Purifying Selection ◽  
Evolutionary Forces ◽  
Polysaccharide Synthesis ◽  
Surface Polysaccharides ◽  
Surface Polysaccharide ◽  
Selective Preservation ◽  
Multiple Species

Bacterial capsules and lipopolysaccharides are diverse surface polysaccharides (SPs) that serve as the frontline for interactions with the outside world. While SPs can evolve rapidly, their diversity and evolutionary dynamics across different taxonomic scales has not been investigated in detail. Here, we focused on the bacterial order Enterobacteriales (including the medically-relevant Enterobacteriaceae), to carry out comparative genomics of two SP locus synthesis regions, cps and kps, using 27,334 genomes from 45 genera. We identified high-quality cps loci in 22 genera and kps in 11 genera, around 4% of which were detected in multiple species. We found SP loci to be highly dynamic genetic entities: their evolution was driven by high rates of horizontal gene transfer (HGT), both of whole loci and component genes, and relaxed purifying selection, yielding large repertoires of SP diversity. In spite of that, we found the presence of (near-)identical locus structures in distant taxonomic backgrounds that could not be explained by recent exchange, pointing to long-term selective preservation of locus structures in some populations. Our results reveal differences in evolutionary dynamics driving SP diversity within different bacterial species, with lineages of Escherichia coli, Enterobacter hormachei and Klebsiella aerogenes most likely to share SP loci via recent exchange; and lineages of Salmonella enterica, Citrobacter sakazakii and Serratia marcescens most likely to share SP loci via other mechanisms such as long-term preservation. Overall, the evolution of SP loci in Enterobacteriales is driven by a range of evolutionary forces and their dynamics and relative importance varies between different species.

scholarly journals Polymeric Nanoparticles Active against Dual-Species Bacterial Biofilms

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4958
Author(s):  
Jessa Marie V. Makabenta ◽  
Jungmi Park ◽  
Cheng-Hsuan Li ◽  
Aritra Nath Chattopadhyay ◽  
Ahmed Nabawy ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Laser Scanning ◽  
Polymeric Nanoparticles ◽  
Bacterial Species ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Biofilms ◽  
Global Public Health ◽  
Bacterial Strains

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. Broad-spectrum antimicrobial activity was observed, with reduction in both bacterial viability and overall biofilm mass. Further, PNPs displayed minimal fibroblast toxicity and high antimicrobial activity in an in vitro co-culture model comprising fibroblast cells and dual-species biofilms of Escherichia coli and Pseudomonas aeruginosa. This study highlights a potential clinical application of the presented polymeric platform.

scholarly journals ANTIBACTERIAL ACTIVITY OF METHANOLIC RHIZOME EXTRACT OF ALPINIA CALCARATA ROSC. (ZINGIBERACEAE)

2016 ◽  
Vol 3 (1) ◽  
pp. 65-66
Author(s):  
Arumugasamy K ◽  
Nantha Kumar R ◽  
Abdul Kaffoor H ◽  
Shalimol A
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Species ◽  
Antibacterial Activities ◽  
Bacterial Activity ◽  
Proteus Vulgaris ◽  
Bacterial Strains ◽  
Zone Of Inhibition

The methanolic rhizome extract of A. calcarata was evaluated for its antibacterial activities against five bacterial strains Pseudomonas aeuroginosa, Proteus vulgaris, Salmonella paratyphi, Bacillus thurungiensis and Staphylococcus faccealis. The extract has inhibited all the tested bacterial species with different manner at various concentration. However the higher level zone of inhibition in 400 (mg/ml) is significant against all the above said bacterial strains of these Salmonella paratyphi. Based on the present study it can be conculuded that the plant rhizome possess potent anti bacterial activity.

scholarly journals Improvement Salt Tolerance of Safflower Plants by Endophytic Bacteria

2019 ◽  
Vol 5 ◽  
pp. 38-56 ◽  
Author(s):  
Khulod A. Hemida ◽  
Amany M.M. Reyad
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Endophytic Bacteria ◽  
Bacterial Species ◽  
Limiting Factors ◽  
Symbiotic Association ◽  
Bacterial Strains ◽  
Growth Promoters ◽  
Wide Range ◽  
Plant Salt Tolerance

Salinity is one of the most dangerous environmental limiting factors of the plant productivity. A wide range of adaptation strategies is required to overcome salinity stress. However, such strategies seem to be long drawn and cost-intensive. It has been confirmed in recent years that plant growth promoting endophytes (PGPEs) that have the ability to further build a symbiotic association with their host to improve host plant salt tolerance. In our investigation try to improve plant salt tolerance using different species of endophytic bacteria. From the total eight endophytic bacterial species were isolated from root, stem, and leaf of Carthamustinctorius (safflower) plant, two isolates were capable of using 1-aminocyclopropane-1-carboxylic acid (ACC) as a sole nitrogen source, and they are of positive results for (ACC) deaminase activity and indole-3-acetic acid (IAA) production. The bacterial isolates were identified using 16S ribosomal DNA technique as Bacillus cereus and Bacillus aerius and had accession numbers MG708176 and MG711593 respectively, by submitting their sequences in GenBank database. This study showed that the bacterial strains B. cereus and B. aerius are valuable biological plant growth promoters that could enhance salt tolerance in Safflower plants under 100, 200, and 300mMNaCl levels resulting in an increase in plant growth and ascorbate-glutathione redox cycle, in comparison with the non-inoculated controls. Our findings reported that the co-inoculation of the two selected endophytic bacteria strains were successfully isolated from Safflower seedlings significantly alleviated the harmful effects of salt stress, promoted plant growth and biomass yield.

scholarly journals Cost-Effective Fabrication, Antibacterial Application and Cell Viability Studies of Modified Nonwoven Cotton Fabric

2021 ◽  
Author(s):  
Rahat Nawaz ◽  
Sayed Tayyab Raza Naqvi ◽  
Batool Fatima ◽  
Nazia Zulfiqar ◽  
Muhammad Umer Farooq ◽  
...  
Keyword(s):  
Cotton Fabric ◽  
Biomedical Applications ◽  
Active Sites ◽  
Food Packaging ◽  
Low Cost ◽  
Bacterial Species ◽  
Enterobacter Aerogenes ◽  
Cost Effective ◽  
Bacterial Strains ◽  
Toxicity Assay

Abstract Nonwoven cotton fabric has been fabricated and designed for antibacterial applications using low cost and ecofriendly precursors. The treatment of fabric with alkali leads to formation of active sites. The surfaces were dip coated with silver nanaoparticles and chitosan. The surface was chlorinated in next step to transform amide (N-H) groups in chitosan into N-halamine (N-Cl). The modified and unmodified surfaces of the nonwoven cotton fabric have been characterized by FTIR, SEM, and XRD. The active chlorine loading is measured with iodine/ sodium thiosulphate. The antimicrobial activity and cell toxicity assay were carried out with and without modifications of nonwoven cotton fabric. The antimicrobial efficacies of loaded fabric were evaluated against four bacterial species (Micrococcus lutes, Staphylococcus aurea, Enterobacter aerogenes, and E.coli). It was found that modified fabric exhibited superior efficiency against gram-positive and gram-negative bacterial strains as compared to their bulk counterparts upon exposure without destroying and affecting fabric nature. The overall process is economical for commercial purposes. The modified fabric can be used for antimicrobial, health, and food packaging industries, and in other biomedical applications.

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