scholarly journals Integrated into Environmental Biofilm Chromobacterium vaccinii Survives Winter with Support of Bacterial Community

2020 ◽  
Vol 8 (11) ◽  
pp. 1696
Author(s):  
Daria A. Egorova ◽  
Olga L. Voronina ◽  
Andrey I. Solovyev ◽  
Marina S. Kunda ◽  
Ekaterina I. Aksenova ◽  
...  

Chromobacterium species are common in tropical and subtropical zones in environmental samples according to numerous studies. Here, we describe an environmental case of resident Chromobacterium vaccinii in biofilms associated with Carex spp. roots in Moscow region, Russia (warm-summer humid continental climate zone). We performed broad characterization of individual properties as well as surrounding context for better understanding of the premise of C. vaccinii survival during the winter season. Genome properties of isolated strains propose some insights into adaptation to habit and biofilm mode of life, including social cheaters carrying ΔluxR mutation. Isolated C. vaccinii differs from previously described strains in some biochemical properties and some basic characteristics like fatty acid composition as well as unique genome features. Despite potential to modulate membrane fluidity and presence of several genes responsible for cold shock response, isolated C. vaccinii did not survive during exposure to 4 °C, while in the complex biofilm sample, it was safely preserved for at least half a year in vitro at 4 °C. The surrounding bacterial community within the same biofilm with C. vaccinii represented a series of psychrophilic bacterial species, which may share resistance to low temperatures with other species within biofilm and provide C. vaccinii an opportunity to survive during the cold winter season.

Author(s):  
Daria A. Egorova ◽  
Olga L. Voronina ◽  
Andrey I. Solovyev ◽  
Marina S. Kunda ◽  
Ekaterina I. Aksenova ◽  
...  

Chromobacterium species are common in tropical and subtropical zones in environmental water samples and believed to «tropical» species. Here we describe an environmental case of resident Chromobacterium vaccinii in biofilms associated with Carex spp. roots in Moscow region, Russia (warm-summer humid continental climate zone). We performed broad characterization of individual properties as well as surrounding context for better understanding the premise of C. vaccinii survival during winter season. Genome properties of isolated strains propose some insights into adaptation to habit and biofilm mode of life, including social cheaters carrying ΔluxR mutation. Isolated C. vaccinii differs with previously described strains in some biochemical properties and some basic characteristics like fatty acid composition as well as unique genome features. Despite potential to modulate membrane fluidity and presence of several genes responsible for cold shock response, isolated C. vaccinii didn`t survive during exposure to 4 °C, while in initial complex biofilm it was able to survive for months in vitro at 4 °C. Surrounding bacterial community within the same biofilm with C. vaccinii represented a series of psychrophilic bacterial species which may share resistance to low temperatures with other species within biofilm and provide C. vaccinii opportunity to survive during cold winter season.


2020 ◽  
Vol 13 (11) ◽  
pp. 1
Author(s):  
A. R. B. Zanco ◽  
A. Ferreira ◽  
G. C. M. Berber ◽  
E. N. Gonzaga ◽  
D. C. C. Sabino

The different integrated production systems can directly interfere with its bacterial community. The present study aimed to assess density, bacterial diversity and the influence of dry and rainy season in different integrated and an exclusive production system. The fallow and a native forest area was assessed to. Samples were collected in 2012 March and September. The isolation were carried out into Petri dishes containing DYGS medium. The number of colony forming units (CFU) was counted after 48 hours and. The bacterial density ranged between 106 and 107 CFU g-1 soil. The crop system affected the dynamics of the bacterial community only in the rainy season. The rainy season showed greater density of total bacteria when compared to the dry period regardless of the cropping system. The dendrograms with 80 % similarity showed thirteen and fourteen groups in the rainy and dry seasons. Isolates with the capacity to solubilize phosphate in vitro were obtained from all areas in the two seasons, but this feature has been prevalent in bacteria isolated during the rainy season


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2904
Author(s):  
Margot Gautier ◽  
Cécile Thirant ◽  
Olivier Delattre ◽  
Isabelle Janoueix-Lerosey

Neuroblastoma, a pediatric cancer of the peripheral sympathetic nervous system, is characterized by an important clinical heterogeneity, and high-risk tumors are associated with a poor overall survival. Neuroblastoma cells may present with diverse morphological and biochemical properties in vitro, and seminal observations suggested that interconversion between two phenotypes called N-type and S-type may occur. In 2017, two main studies provided novel insights into these subtypes through the characterization of the transcriptomic and epigenetic landscapes of a panel of neuroblastoma cell lines. In this review, we focus on the available data that define neuroblastoma cell identity and propose to use the term noradrenergic (NOR) and mesenchymal (MES) to refer to these identities. We also address the question of transdifferentiation between both states and suggest that the plasticity between the NOR identity and the MES identity defines a noradrenergic-to-mesenchymal transition, reminiscent of but different from the well-established epithelial-to-mesenchymal transition.


1985 ◽  
Vol 22 (4) ◽  
pp. 375-386 ◽  
Author(s):  
H. C. Wimberly ◽  
D. O. Slauson ◽  
N. R. Neilsen

Antigen-specific challenge of equine leukocytes induced the non-lytic release of a platelet-activating factor in vitro. The equine platelet-activating factor stimulated the release of serotonin from equine platelets in a dose-responsive manner, independent of the presence of cyclo-oxygenase pathway inhibitors such as indomethacin. Rabbit platelets were also responsive to equine platelet-activating factor. The release of equine platelet-activating factor was a rapid reaction with near maximal secretion taking place in 30 seconds. Addition of equine platelet-activating factor to washed equine platelets stimulated platelet aggregation which could not be inhibited by the presence of aspirin or indomethacin. Platelets preincubated with equine platelet-activating factor became specifically desensitized to equine platelet-activating factor while remaining responsive to other platelet stimuli such as collagen and epinephrine. The following biochemical properties of equine platelet-activating factor are identical to those properties of 1-0-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (AGEPC): stability upon exposure to air and acid; loss of functional activity after basecatalyzed methanolysis with subsequent acylation that returned all functional activity; and identical relative mobilities on silica gel G plates developed with chloroform:methanol:water (65:35:6, volume/volume). The combined functional and biochemical characteristics of equine platelet-activating factor strongly suggest identity between this naturally occurring, immunologically derived equine factor and AGEPC.


2007 ◽  
Vol 405 (3) ◽  
pp. 455-463 ◽  
Author(s):  
Alain Doucet ◽  
Dominique Bouchard ◽  
Marie France Janelle ◽  
Audrey Bellemare ◽  
Stéphane Gagné ◽  
...  

Pre-elafin is a tight-binding inhibitor of neutrophil elastase and myeloblastin; two enzymes thought to contribute to tissue damage in lung emphysema. Previous studies have established that pre-elafin is also an effective anti-inflammatory molecule. However, it is not clear whether both functions are linked to the antipeptidase activity of pre-elafin. As a first step toward elucidating the structure/function relationship of this protein, we describe here the construction and characterization of pre-elafin variants with attenuated antipeptidase potential. In these mutants, the P1′ methionine residue of the inhibitory loop is replaced by either a lysine (pre-elafinM25K) or a glycine (pre-elafinM25G) residue. Both mutated variants are stable and display biochemical properties undistinguishable from WT (wild-type) pre-elafin. However, compared with WT pre-elafin, their inhibitory constants are increased by one to four orders of magnitude toward neutrophil elastase, myeloblastin and pancreatic elastase, depending on the variants and enzymes tested. As suggested by molecular modelling, this attenuated inhibitory potential correlates with decreased van der Waals interactions between the variants and the enzymes S1′ subsite. In elastase-induced experimental emphysema in mice, only WT pre-elafin protected against tissue destruction, as assessed by the relative airspace enlargement measured using lung histopathological sections. Pre-elafin and both mutants prevented transient neutrophil alveolitis. However, even the modestly affected pre-elafinM25K mutant, as assayed in vitro with small synthetic substrates, was a poor inhibitor of the neutrophil elastase and myeloblastin elastolytic activity measured with insoluble elastin. We therefore conclude that full antipeptidase activity of pre-elafin is essential to protect against lung tissue lesions in this experimental model.


2020 ◽  
Vol 110 (5) ◽  
pp. 989-998
Author(s):  
Cláudio M. Vrisman ◽  
Loïc Deblais ◽  
Yosra A. Helmy ◽  
Reed Johnson ◽  
Gireesh Rajashekara ◽  
...  

Plant pathogenic bacteria in the genus Erwinia cause economically important diseases, including bacterial wilt of cucurbits caused by Erwinia tracheiphila. Conventional bactericides are insufficient to control this disease. Using high-throughput screening, 464 small molecules (SMs) with either cidal or static activity at 100 µM against a cucumber strain of E. tracheiphila were identified. Among them, 20 SMs (SM1 to SM20), composed of nine distinct chemical moiety structures, were cidal to multiple E. tracheiphila strains at 100 µM. These lead SMs had low toxicity to human cells and honey bees at 100 µM. No phytotoxicity was observed on melon plants at 100 µM, except when SM12 was either mixed with Silwet L-77 and foliar sprayed or when delivered through the roots. Lead SMs did not inhibit the growth of beneficial Pseudomonas and Enterobacter species but inhibited the growth of Bacillus species. Nineteen SMs were cidal to Xanthomonas cucurbitae and showed >50% growth inhibition against Pseudomonas syringae pv. lachrymans. In addition, 19 SMs were cidal or static against Erwinia amylovora in vitro. Five SMs demonstrated potential to suppress E. tracheiphila when foliar sprayed on melon plants at 2× the minimum bactericidal concentration. Thirteen SMs reduced Et load in melon plants when delivered via roots. Temperature and light did not affect the activity of SMs. In vitro cidal activity was observed after 3 to 10 h of exposure to these five SMs. Here, we report 19 SMs that provide chemical scaffolds for future development of bactericides against plant pathogenic bacterial species.


Author(s):  
Michael E. Stender ◽  
Christian R. Flores ◽  
Kristin J. Dills ◽  
Gregory M. Williams ◽  
Kevin M. Stewart ◽  
...  

Articular cartilage (AC) is a load bearing material that provides a low friction wear resistant interface in synovial joints. Naturally-occurring and stimulated intrinsic repair of damaged AC is ineffective. Thus, there is a desire to engineer effective replacement tissue that could be used for AC repair. Previous studies [1] have shown that culture of immature cartilage with medium including TGF-β1 will result in a more mature tissue than culture with IGF-1. Detailed characterization of tissue mechanical properties would be helpful for development of cartilage growth models [2].


Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1143 ◽  
Author(s):  
Rasmus Riemer Jakobsen ◽  
Thor Haahr ◽  
Peter Humaidan ◽  
Jørgen Skov Jensen ◽  
Witold Piotr Kot ◽  
...  

Bacterial vaginosis (BV) is characterized by a reduction in Lactobacillus (L.) spp. abundance and increased abundance of facultative anaerobes, such as Gardnerella spp. BV aetiology is not fully understood; however, bacteriophages could play a pivotal role in the perturbation of the vaginal bacterial community. We investigated the vaginal viral community, including bacteriophages and the association to the bacterial community and BV-status. Vaginal samples from 48 patients undergoing IVF treatment for non-female factor infertility were subjected to metagenomic sequencing of purified virus-like particles. The vaginal viral community was characterized and correlated with the BV-status by Nugent score, bacterial community, structure, and the presence of key vaginal bacterial species. The majority of identified vaginal viruses belonged to the class of double-stranded DNA bacteriophages, with eukaryotic viruses constituting 4% of the total reads. Clear links between the viral community composition and BV (q = 0.006, R = 0.26) as well as the presence of L. crispatus (q = 0.001, R = 0.43), L. iners, Gardnerella spp., and Atopobium vaginae were found (q < 0.002, R > 0.15). The eukaryotic viral community also correlated with BV-status (q = 0.018, R = 0.20). In conclusion, the vaginal virome was clearly linked with bacterial community structure and BV-status.


1978 ◽  
Vol 79 (1) ◽  
pp. 217-234 ◽  
Author(s):  
P J Oates ◽  
O Touster

To investigate the properties of phagolysosome (PL) fusion in Acanthamoeba homogenates, it was necessary to develop reliable methods for measuring in vitro PL fusion. The need to distinguish PL fusion from PL adhesion was met by the development of a quantitative electron microscope assay. Initial characterization of the fusion reaction by this method was followed by the development of a more rapid light microscope assay. Results obtained by the two methods were found to be in close agreement. By use of these new techniques, the in vitro PL fusion reaction was demonstrated to occur in a quantitatively reproducible manner. Under the present conditions employed, PL breakdown was not detected at any time during the in vitro incubation, while PL fusion was observed to proceed linearly for approximately 10 min, at which time the reaction ceased. Incubation of mixtures of two distinct PL types resulted in increases in hybrid PL types that were paralleled by decreases in nonhybrid PL types. The relative changes in PL concentrations observed were quantitatively consistent with PL fusion occurring randomly with respect to PL type. PL fusion was strongly inhibited by low concentrations of KF (50% inhibition at 2.7 mM), and by approximately tenfold higher concentrations of KCl, while KCN and 2,4-dinitrophenol (2,4-DNP) had little effect. In addition to further defining the nature of the PL fusion reaction in this system, these results demonstrate that, by use of the techniques described, quantitative study of the biochemical properties of this reaction is now possible.


2020 ◽  
Vol 13 (11) ◽  
pp. 1
Author(s):  
A. R. B. Zanco ◽  
A. Ferreira ◽  
G. C. M. Berber ◽  
E. N. Gonzaga ◽  
D. C. C. Sabino

The different integrated production systems can directly interfere with its bacterial community. The present study aimed to assess density, bacterial diversity and the influence of dry and rainy season in different integrated and an exclusive production system. The fallow and a native forest area was assessed to. Samples were collected in 2012 March and September. The isolation were carried out into Petri dishes containing DYGS medium. The number of colony forming units (CFU) was counted after 48 hours and. The bacterial density ranged between 106 and 107 CFU g-1 soil. The crop system affected the dynamics of the bacterial community only in the rainy season. The rainy season showed greater density of total bacteria when compared to the dry period regardless of the cropping system. The dendrograms with 80 % similarity showed thirteen and fourteen groups in the rainy and dry seasons. Isolates with the capacity to solubilize phosphate in vitro were obtained from all areas in the two seasons, but this feature has been prevalent in bacteria isolated during the rainy season.


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