scholarly journals The planctomycete Stieleria maiorica Mal15T employs stieleriacines to alter the species composition in marine biofilms

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Nicolai Kallscheuer ◽  
Olga Jeske ◽  
Birthe Sandargo ◽  
Christian Boedeker ◽  
Sandra Wiegand ◽  
...  
Keyword(s):  
Species Composition ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Lag Phase ◽  
The Novel ◽  
Bacterial Strains ◽  
Functional Link ◽  
Genetic Organisation ◽  
Marine Biofilms ◽  
The Phylum Planctomycetes

AbstractBacterial strains of the phylum Planctomycetes occur ubiquitously, but are often found on surfaces of aquatic phototrophs, e.g. alga. Despite slower growth, planctomycetes are not outcompeted by faster-growing bacteria in biofilms on such surfaces; however, strategies allowing them to compensate for slower growth have not yet been investigated. Here, we identified stieleriacines, a class of N-acylated tyrosines produced by the novel planctomycete Stieleria maiorica Mal15T, and analysed their effects on growth of the producing strain and bacterial species likely co-occurring with strain Mal15T. Stieleriacines reduced the lag phase of Mal15T and either stimulated or inhibited biofilm formation of two bacterial competitors, indicating that Mal15T employs stieleriacines to specifically alter microbial biofilm composition. The genetic organisation of the putative stieleriacine biosynthetic cluster in strain Mal15T points towards a functional link of stieleriacine biosynthesis to exopolysaccharide-associated protein sorting and biofilm formation.

scholarly journals Selection of microorganisms degrading S-Metolachlor herbicide

2007 ◽  
Vol 50 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Paula Fabiane Martins ◽  
Camila Ortiz Martinez ◽  
Giselle de Carvalho ◽  
Paulo Irajara Borba Carneiro ◽  
Ricardo Antunes Azevedo ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Enterobacter Aerogenes ◽  
Lag Phase ◽  
Herbicide Degradation ◽  
Color Changes ◽  
The Difference ◽  
Selection Of Microorganisms ◽  
Selection Of

The aim of this work was to study herbicide degradation through selected microorganisms from humus and soil subjected to different plantation systems. The following bacterial species were identified: Klebsiella pneumoniae pneumoniae GC s.B strain 1, Pseudomonas alcaligenes, Enterobacter aerogenes GC s.A and Klebsiella pneumoniae pneumoniae GC s.B strain 2. Growth studies yet suggested the possibility of a very long lag phase. Although, culture with the herbicide presented biofilm formation and there were color changes in the herbicide that could have interfered with the espectrophotometry readings. After 5 days of incubation at 35ºC, the difference in the concentration of herbicide was 14.42% on average and after 10 days, 35.01%.

Calcium removal by softening of water affects biofilm formation on PVC, glass and membrane surfaces

2016 ◽  
Vol 16 (4) ◽  
pp. 888-895 ◽  
Author(s):  
W. A. M. Hijnen ◽  
F. Schultz ◽  
D. J. H. Harmsen ◽  
A. H. Brouwer-Hanzens ◽  
P. W. J. J. van der Wielen ◽  
...  
Keyword(s):  
Species Composition ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Polymorphism Analysis ◽  
Physiological Mechanisms ◽  
Atp Production ◽  
Membrane Surfaces ◽  
Calcium Removal ◽  
Ro Membrane ◽  
Substrate Concentrations

Literature data on the effect of calcium on biofilm structures induced a preliminary study. The effect of calcium removal by water softening (<1.0 mg Ca2+.L−1) under real-world drinking water conditions on biofilm formation was studied in a pilot plant with reverse osmosis (RO) membranes and in a laboratory-scale biofilm production unit (BPU) with plasticized polyvinyl chloride (PVC-P) and glass as substratum. The results showed a halving of the exponential biofouling rate in the RO membrane and also a halving of the exponential carbohydrate (CH) production rate in the biofilm on PVC-P and glass in the BPU by softening of the water. In PVC-P biofilms, softening did not affect adenosine tri-phosphate (ATP) production and bacterial species composition (terminal restriction fragment length polymorphism analysis). At low substrate concentrations in glass and RO membrane biofilms softening reduced significantly ATP and CH production and changed the species composition on the membrane. The importance of the two hypothesized physical or physiological mechanisms as causes for the observed Ca2+ effect on biofilm formation and the effect of Ca2+ concentration on those, needs further studies.

scholarly journals The relationship between biofilm formation, genes of virulence and iron metabolism in Escherichia coli

2018 ◽  
Author(s):  
Lívia Handrová ◽  
Anna Čuvalová ◽  
Vladimír Kmeť
Keyword(s):  
Escherichia Coli ◽  
Iron Metabolism ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Opportunistic Infections ◽  
Bacterial Species ◽  
Pcr Amplification ◽  
Bacterial Strains ◽  
E Coli ◽  
Wide Range

Escherichia coli is known as one of the bacterial species with the widest adaptability to variety of niches either within organisms or outside in environment. Most strains of E. coli are of low virulence and associated with opportunistic infections, whereas others are highly virulent. The success of E. coli in colonising such a wide range of hosts and environments is basically due to a noticeable ductility in exploiting the available resources. It is becoming increasingly clear that biofilms have an enormous impact on medicine because since 65% of animal and human bacterial infections involve biofilms. In present study, we isolated strains of E. coli from animals. 19 interesting isolates were selected and tested by PCR amplification to virulence – iutA, cvaC, iss, tsh, papC, kps, iha and iron metabolism genes – sitA, feoB, irp2, fyuA, iroN, ireA. The ability of biofilm formation was assessed in a quantitative assay using a microtiter-plate test. Bacterial strains were grown on BHI. We divided isolates of E. coli into four classes: very weak (63.0%), weak (10.5%), moderate (10.5%) and strong (16.0%) biofilm producers. Representation genes of virulence were highly in isolates from very weak biofilm producers – from 7 genes were 6 highly; only papC (P fimbrial adhesin) was low. Genes of iron metabolism were different. Genes – sitA, fyuA, ireA in strong isolates producing biofilm and feoB, irp2, iroN in weak producers were most represented. The results show possible relation between presence virulence factor and low biofilm formation.

scholarly journals SPECIES COMPOSITION OF ASSOCIATIONS AND RELATIONSHIPS BETWEEN MICROORGANISMS ISOLATED FROM OSTEOMYELITIS FOCUS

2021 ◽  
Vol 29 (2) ◽  
pp. 183-190
Author(s):  
I.V. Shipitsyna ◽  
◽  
E.V. Osipova ◽  
A.A. Natalskiy ◽  
A.V. Pavlov ◽  
...  
Keyword(s):  
Species Composition ◽  
Biofilm Formation ◽  
Specific Weight ◽  
Moderate Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Film Forming

Objective. To determine the species composition of the associations isolated from osteomyelitis foci and to study the character of associate relationships based on the biofilm-forming ability data. Methods. The microbiological study included clinical isolates (n=184) obtained from associations (n=88) during primary inoculations from wounds and fistulas of patients (n= 88) with chronic osteomyelitis of long tubular bones. In order to obtain an associative biofilm in vitro, the cultures of competing bacterial strains were daily mixed in 1:1 ratio. The biofilms were grown on the surface of polystyrene plates with subsequent determination of the level of biofilm formation in 24 and 48 hours. Thecoefficient of relationship (CR) was calculated to evaluate the synergistic, neutral and antagonistic relationships between bacteria in the biofilms. Results. The associations of staphylococcus with gram-negative bacteria were most frequently recovered from osteomyelitis foci. On the 1st day of the experiment, 38,6 % of associations had a moderate biofilm-forming ability, and besides, associations of gram-positive + gram-negative bacteria were observed in 36,4%; 42,1% of associations had a low biofilm-forming ability; 19,3% - had a high biofilm-forming ability. After 48 hours the percentage of mild adhesive strains remained at the same level - 38,6%, as for the low adhesive ones it decreased to 36,4%, high adhesive - increased up to 25%. Most bacterial associations manifested antagonistic relationships. Synergism in biofilm-formingby the association of S. aureus + P. aeruginosa was observed in 2 cases,while the level of film-forming was high as on the first and the second day of the study. In several associations it transformed from antagonistic to synergistic or neutral relationships. Conclusion. It has ben established that among the identified associations, the largest specific weight falls on the associations of gram-positive + gram-negative bacteria , while S. aureus is one of the most common components. These associations were noted to have high and mild activity of biofilm -forming on the surface of polystyrene plates. Relationships between the microorganisms isolated from osteomyelitis foci in associations, as a rule, are antagonistic. What this paper adds For the first time, the nature of the relationship between microorganisms in the composition of associations isolated from the osteomyelitis focus has been studied on the basis of biofilm-forming ability data. It has been established that in microbiocenosis of the osteomyelitis foci, the greatest specific weight falls on the associations of S. aureus with gram-negative bacteria. These associations have a high and moderate activity of biofilm formation on the surface of polystyrene plates. The relationships between microorganisms isolated from the osteomyelitis focus as part of associations are usually antagonistic.

scholarly journals Biofilm Formation Drives Transfer of the Conjugative Element ICEBs1inBacillus subtilis

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Frédéric Lécuyer ◽  
Jean-Sébastien Bourassa ◽  
Martin Gélinas ◽  
Vincent Charron-Lamoureux ◽  
Vincent Burrus ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
High Rate ◽  
Conjugative Transfer ◽  
Bacterial Strains ◽  
Content Type

ABSTRACTHorizontal gene transfer by integrative and conjugative elements (ICEs) is a very important mechanism for spreading antibiotic resistance in various bacterial species. In environmental and clinical settings, most bacteria form biofilms as a way to protect themselves against extracellular stress. However, much remains to be known about ICE transfer in biofilms. Using ICEBs1fromBacillus subtilis, we show that the natural conjugation efficiency of this ICE is greatly affected by the ability of the donor and recipient to form a biofilm. ICEBs1transfer considerably increases in biofilm, even at low donor/recipient ratios. Also, while there is a clear temporal correlation between biofilm formation and ICEBs1transfer, biofilms do not alter the level of ICEBs1excision in donor cells. Conjugative transfer appears to be favored by the biophysical context of biofilms. Indeed, extracellular matrix production, particularly from the recipient cells, is essential for biofilms to promote ICEBs1transfer. Our study provides basic new knowledge on the high rate of conjugative transfer of ICEs in biofilms, a widely preponderant bacterial lifestyle in the environment, which could have a major impact on our understanding of horizontal gene transfer in natural and clinical environments.IMPORTANCETransfer of mobile genetic elements from one bacterium to another is the principal cause of the spread of antibiotic resistance. However, the dissemination of these elements in environmental contexts is poorly understood. In clinical and environmental settings, bacteria are often found living in multicellular communities encased in a matrix, a structure known as a biofilm. In this study, we examined how forming a biofilm influences the transmission of an integrative and conjugative element (ICE). Using the model Gram-positive bacteriumB. subtilis, we observed that biofilm formation highly favors ICE transfer. This increase in conjugative transfer is due to the production of extracellular matrix, which creates an ideal biophysical context. Our study provides important insights into the role of the biofilm structure in driving conjugative transfer, which is of major importance since biofilm is a widely preponderant bacterial lifestyle for clinically relevant bacterial strains.

Modulation of Gut Microbiota through Dietary Phytochemicals as a Novel Anti-infective Strategy

2020 ◽  
Vol 17 (4) ◽  
pp. 498-506 ◽  
Author(s):  
Pavan K. Mujawdiya ◽  
Suman Kapur
Keyword(s):  
Microbial Community ◽  
Quorum Sensing ◽  
Population Density ◽  
Gut Microbiota ◽  
Biofilm Formation ◽  
Chemical Interaction ◽  
Bacterial Species ◽  
Critical Role ◽  
Bacterial Cells ◽  
Gut Microbes

: Quorum Sensing (QS) is a phenomenon in which bacterial cells communicate with each other with the help of several low molecular weight compounds. QS is largely dependent on population density, and it triggers when the concentration of quorum sensing molecules accumulate in the environment and crosses a particular threshold. Once a certain population density is achieved and the concentration of molecules crosses a threshold, the bacterial cells show a collective behavior in response to various chemical stimuli referred to as “auto-inducers”. The QS signaling is crucial for several phenotypic characteristics responsible for bacterial survival such as motility, virulence, and biofilm formation. Biofilm formation is also responsible for making bacterial cells resistant to antibiotics. : The human gut is home to trillions of bacterial cells collectively called “gut microbiota” or “gut microbes”. Gut microbes are a consortium of more than 15,000 bacterial species and play a very crucial role in several body functions such as metabolism, development and maturation of the immune system, and the synthesis of several essential vitamins. Due to its critical role in shaping human survival and its modulating impact on body metabolisms, the gut microbial community has been referred to as “the forgotten organ” by O`Hara et al. (2006) [1]. Several studies have demonstrated that chemical interaction between the members of bacterial cells in the gut is responsible for shaping the overall microbial community. : Recent advances in phytochemical research have generated a lot of interest in finding new, effective, and safer alternatives to modern chemical-based medicines. In the context of antimicrobial research various plant extracts have been identified with Quorum Sensing Inhibitory (QSI) activities among bacterial cells. This review focuses on the mechanism of quorum sensing and quorum sensing inhibitors isolated from natural sources.

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

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 Comparative genomics suggests a taxonomic revision of the Staphylococcus cohnii species complex

2021 ◽  
Author(s):  
Anna Lavecchia ◽  
Matteo Chiara ◽  
Caterina De Virgilio ◽  
Caterina Manzari ◽  
Carlo Pazzani ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Species Complex ◽  
Large Scale ◽  
Genomic Sequence ◽  
Bacterial Species ◽  
Taxonomic Revision ◽  
Distinct Species ◽  
The Novel ◽  
Staphylococcus Cohnii ◽  
Taxonomic Assignments

Abstract Staphylococcus cohnii (SC), a coagulase-negative bacterium, was first isolated in 1975 from human skin. Early phenotypic analyses led to the delineation of two subspecies (subsp.), Staphylococcus cohnii subsp. cohnii (SCC) and Staphylococcus cohnii subsp. urealyticus (SCU). SCC was considered to be specific to humans whereas SCU apparently demonstrated a wider host range, from lower primates to humans. The type strains ATCC 29974 and ATCC 49330 have been designated for SCC and SCU, respectively. Comparative analysis of 66 complete genome sequences—including a novel SC isolate—revealed unexpected patterns within the SC complex, both in terms of genomic sequence identity and gene content, highlighting the presence of 3 phylogenetically distinct groups. Based on our observations, and on the current guidelines for taxonomic classification for bacterial species, we propose a revision of the SC species complex. We suggest that SCC and SCU should be regarded as two distinct species: SC and SU (Staphylococcus urealyticus), and that two distinct subspecies, SCC and SCB (SC subsp. barensis, represented by the novel strain isolated in Bari) should be recognized within SC. Furthermore, since large scale comparative genomics studies recurrently suggest inconsistencies or conflicts in taxonomic assignments of bacterial species, we believe that the approach proposed here might be considered for more general application.

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