scholarly journals Beyond the Wall: Exopolysaccharides in the Biofilm Lifestyle of Pathogenic and Beneficial Plant-Associated Pseudomonas

2021 ◽  
Vol 9 (2) ◽  
pp. 445
Author(s):  
Zaira Heredia-Ponce ◽  
Antonio de Vicente ◽  
Francisco M. Cazorla ◽  
José Antonio Gutiérrez-Barranquero
Keyword(s):  
Extracellular Matrix ◽  
Biofilm Formation ◽  
Clinical Importance ◽  
Ecological Significance ◽  
Human Pathogen ◽  
Metabolic Versatility ◽  
Polysaccharide Synthesis ◽  
Biofilm Architecture ◽  
Opportunistic Human Pathogen ◽  
Genetic Context

The formation of biofilms results from a multicellular mode of growth, in which bacteria remain enwrapped by an extracellular matrix of their own production. Many different bacteria form biofilms, but among the most studied species are those that belong to the Pseudomonas genus due to the metabolic versatility, ubiquity, and ecological significance of members of this group of microorganisms. Within the Pseudomonas genus, biofilm studies have mainly focused on the opportunistic human pathogen Pseudomonas aeruginosa due to its clinical importance. The extracellular matrix of P. aeruginosa is mainly composed of exopolysaccharides, which have been shown to be important for the biofilm architecture and pathogenic features of this bacterium. Notably, some of the exopolysaccharides recurrently used by P. aeruginosa during biofilm formation, such as the alginate and polysaccharide synthesis loci (Psl) polysaccharides, are also used by pathogenic and beneficial plant-associated Pseudomonas during their interaction with plants. Interestingly, their functions are multifaceted and seem to be highly dependent on the bacterial lifestyle and genetic context of production. This paper reviews the functions and significance of the exopolysaccharides produced by plant-associated Pseudomonas, particularly the alginate, Psl, and cellulose polysaccharides, focusing on their equivalents produced in P. aeruginosa within the context of pathogenic and beneficial interactions.

scholarly journals Exopolysaccharide biosynthetic glycoside hydrolases can be utilized to disrupt and preventPseudomonas aeruginosabiofilms

2015 ◽  
Author(s):  
Perrin Baker ◽  
Preston J HIll ◽  
Brendan D Snarr ◽  
Noor Alnabelseya ◽  
Mathew J Pestrak ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Glycoside Hydrolases ◽  
Bacterial Biofilms ◽  
Human Pathogen ◽  
Host Defenses ◽  
Bacterial Exopolysaccharide ◽  
Opportunistic Human Pathogen ◽  
Potential Therapeutics

Bacterial biofilms are a significant medical challenge as they are recalcitrant to current therapeutic regimes. A key component of biofilm formation in the opportunistic human pathogenPseudomonas aeruginosais the biosynthesis of the exopolysaccharides Pel and Psl, which are involved in the formation and maintenance of the structural biofilm scaffold and protection against antimicrobials and host defenses. Given that the glycoside hydrolases - PelAhand PslGh- encoded in thepelandpslbiosynthetic operons, respectively, are utilized for in vivo exopolysaccharide processing, we reasoned that these would provide specificity to targetP. aeruginosabiofilms. Evaluating these enzymes as potential therapeutics, we demonstrate that these glycoside hydrolases selectively target and degrade the exopolysaccharide component of the biofilm matrix and that nanomolar concentrations of these enzymes can both prevent biofilm formation as well as rapidly disrupt preexisting biofilms in vitro. This treatment was effective against clinical and environmental P. aeruginosa isolates and reduced biofilm biomass by 58-94%. These non-cytotoxic enzymes potentiated antibiotics as the addition of either enzyme to a sub-lethal concentration of colistin reduced viable bacterial counts by 2.5 orders of magnitude. Additionally, PelAhwas able to increase neutrophil killing by ~50%. This work illustrates the feasibility and benefits of using bacterial exopolysaccharide biosynthetic glycoside hydrolases and synthetic biology to develop novel anti-biofilm therapeutics.

Bacterial adherence and biofilm behavior of Vibrio vulnificus

1993 ◽  
Vol 51 ◽  
pp. 378-379
Author(s):  
B. D. Tall ◽  
R. T. Gray ◽  
D. B. Shah
Keyword(s):  
Electron Microscopy ◽  
Biofilm Formation ◽  
Vibrio Vulnificus ◽  
Ruthenium Red ◽  
Human Pathogen ◽  
Normal Microflora ◽  
Microscopic Studies ◽  
Plate Counts ◽  
Opportunistic Human Pathogen ◽  
Phase Variants

Vibrio vulnificus, an opportunistic human pathogen, is found as member of the normal microflora of shellfish and other seafoods, many of which are eaten raw. Though usually not harmful, V. vulnificus is responsible for causing fulminating septicemia in immunocompromised individuals. In previous light microscopic studies, we showed data suggesting that isogenic unencapsulated phase variants were more adherent to HeLa cells than were counterpart encapsulated phase variants. In this study, we extended our observations by comparing phase variant capsular morphology stained with Alcian blue (AB) and Ruthenium red (RR), and investigated the dynamics of biofilm formation by these organisms to glass coverslips (CS) using quantitative plate counts and scanning electron microscopy (SEM).To characterize the morphology of capsules expressed by these organisms, we stained cells grown on trypticase soy agar containing 1 % NaCl (TSA/NaCl) with AB and then prepared them for electron microscopy (EM) according to the method described by Hendley et al.

scholarly journals Pseudomonas aeruginosa Condensins Support Opposite Differentiation States

2016 ◽  
Vol 198 (21) ◽  
pp. 2936-2944 ◽  
Author(s):  
Hang Zhao ◽  
April L. Clevenger ◽  
Jerry W. Ritchey ◽  
Helen I. Zgurskaya ◽  
Valentin V. Rybenkov
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Competitive Growth ◽  
Human Pathogen ◽  
Functional Protein ◽  
Content Type ◽  
Bacterial Physiology ◽  
Growth Defects ◽  
Bacterial Pathogenicity ◽  
Opportunistic Human Pathogen

ABSTRACTCondensins play a key role in global chromosome packing.Pseudomonas aeruginosaencodes two condensins, SMC-ScpAB and MksBEF. We report here that the two proteins are involved in the differentiation of the bacterium and impose opposite physiological states. The inactivation of SMC induced a state characterized by increased adhesion to surfaces as well as defects in competitive growth and colony formation. In contrast, MksB-deficient cells were impaired in biofilm formation with no obvious defects during planktonic growth. The phenotype of the double mutant was dominated by the absence of MksB, indicating that the observed growth defects are regulatory in their nature rather than structural. ATPase mutations recapitulated many of the phenotypes of the condensins, indicating their requirement for a functional protein. Additionally, inactivation of condensins dramatically reduced the virulence of the bacterium in a murine model of lung infection. These data demonstrate that condensins are involved in the differentiation ofP. aeruginosaand reveal their importance for pathogenicity.IMPORTANCEAdaptation and differentiation play key roles in bacterial pathogenicity. InPseudomonas aeruginosa, an opportunistic human pathogen, these processes are mediated by the activity of an intricate regulatory network. We describe here novel members of this network, condensins. We show that the twoP. aeruginosacondensins specialize in the establishment of the sessile and planktonic states of the bacterium. Whereas condensins have well-established roles in global chromosome organization, their roles in regulating bacterial physiology have remained unknown. Our data indicate that the two programs may be linked. We further show that condensins are essential for the pathogenicity ofP. aeruginosa.

scholarly journals A Candida parapsilosis Overexpression Collection Reveals Genes Required for Pathogenesis

2021 ◽  
Vol 7 (2) ◽  
pp. 97
Author(s):  
Sára E. Pál ◽  
Renáta Tóth ◽  
Joshua D. Nosanchuk ◽  
Csaba Vágvölgyi ◽  
Tibor Németh ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Deletion Mutant ◽  
Candida Parapsilosis ◽  
Galleria Mellonella ◽  
Mutant Library ◽  
Human Pathogen ◽  
Opportunistic Human Pathogen ◽  
Mutant Collection

Relative to the vast data regarding the virulence mechanisms of Candida albicans, there is limited knowledge on the emerging opportunistic human pathogen Candida parapsilosis. The aim of this study was to generate and characterize an overexpression mutant collection to identify and explore virulence factors in C. parapsilosis. With the obtained mutants, we investigated stress tolerance, morphology switch, biofilm formation, phagocytosis, and in vivo virulence in Galleria mellonella larvae and mouse models. In order to evaluate the results, we compared the data from the C. parapsilosis overexpression collection analysis to the results derived from previous deletion mutant library characterizations. Of the 37 overexpression C. parapsilosis mutants, we identified eight with altered phenotypes compared to the controls. This work is the first report to identify CPAR2_107240, CPAR2_108840, CPAR2_302400, CPAR2_406400, and CPAR2_602820 as contributors to C. parapsilosis virulence by regulating functions associated with host-pathogen interactions and biofilm formation. Our findings also confirmed the role of CPAR2_109520, CPAR2_200040, and CPAR2_500180 in pathogenesis. This study was the first attempt to use an overexpression strategy to systematically assess gene function in C. parapsilosis, and our results demonstrate that this approach is effective for such investigations.

scholarly journals Complete Genome Sequence of Stenotrophomonas Phage Mendera

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Kameron D. Garza ◽  
Heather Newkirk ◽  
Russell Moreland ◽  
Carlos F. Gonzalez ◽  
Mei Liu ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Stenotrophomonas Maltophilia ◽  
Human Pathogen ◽  
Base Pairs ◽  
Content Type ◽  
Genomic Annotation ◽  
Opportunistic Human Pathogen

Stenotrophomonas maltophilia is an emerging opportunistic human pathogen. In this report, we describe the isolation and genomic annotation of the S. maltophilia-infecting bacteriophage Mendera. A myophage of 159,961 base pairs, Mendera is T4-like and related most closely to Stenotrophomonas phage IME-SM1.

Influence of Glucose Concentrations on Biofilm Formation, Motility, Exoprotease Production, and Quorum Sensing in Aeromonas hydrophila

2013 ◽  
Vol 76 (2) ◽  
pp. 239-247 ◽  
Author(s):  
IQBAL KABIR JAHID ◽  
NA-YOUNG LEE ◽  
ANNA KIM ◽  
SANG-DO HA
Keyword(s):  
Quorum Sensing ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Homoserine Lactone ◽  
Protease Production ◽  
Acyl Homoserine Lactone ◽  
Human Pathogen ◽  
Initial Biofilm ◽  
Motility Inhibition

Aeromonas hydrophila recently has received increased attention because it is opportunistic and a primary human pathogen. A. hydrophila biofilm formation and its control are a major concern for food safety because biofilms are related to virulence. Therefore, we investigated biofilm formation, motility inhibition, quorum sensing, and exoprotease production of this opportunistic pathogen in response to various glucose concentrations from 0.05 to 2.5% (wt/vol). More than 0.05% glucose significantly impaired (P < 0.05) quorum sensing, biofilm formation, protease production, and swarming and swimming motility, whereas bacteria treated with 0.05% glucose had activity similar to that of the control (0% glucose). A stage shift biofilm assay revealed that the addition of glucose (2.5%) inhibited initial biofilm formation but not later stages. However, addition of quorum sensing molecules N-3-butanoyl-DL-homoserine lactone and N-3-hexanoyl homoserine lactone partially restored protease production, indicating that quorum sensing is controlled by glucose concentrations. Thus, glucose present in food or added as a preservative could regulate acyl-homoserine lactone quorum sensing molecules, which mediate biofilm formation and virulence in A. hydrophila.

Pseudomonas aeruginosa transition from environmental generalist to human pathogen

2021 ◽  
Vol 13 (1) ◽  
pp. 11
Author(s):  
Gabriela Vasco ◽  
Gabriel Trueba
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Human Body ◽  
Biofilm Formation ◽  
Reduction Reaction ◽  
Human Pathogen ◽  
Opportunistic Bacteria ◽  
Oxidation Reduction ◽  
Mammalian Tissues ◽  
Oxidation Reduction Reaction ◽  
Source Sink

Opportunistic bacteria Pseudomonas aeruginosa is one of the major concerns as an etiological agent of nosocomial infections in humans. Many virulence factors used to colonize the human body are the same as those used by P. aeruginosa to thrive in the environment such as membrane transport, biofilm formation, oxidation/reduction reaction, among others. P. aeruginosa origin is mainly from the environment, the adaptation to mammalian tissues may follow a source-sink evolution model; the environment is the source of many lineages, some of them capable of adaptation to the human body. Some lineages may adapt to humans and go through reductive evolution in which some genes are lost.  The understanding of this process may be critical to implement better methods to control outbreaks in hospitals.

scholarly journals Bacteriophages LIMElight and LIMEzero of Pantoea agglomerans, Belonging to the “phiKMV-Like Viruses”

2011 ◽  
Vol 77 (10) ◽  
pp. 3443-3450 ◽  
Author(s):  
Evelien M. Adriaenssens ◽  
Pieter-Jan Ceyssens ◽  
Vincent Dunon ◽  
Hans-Wolfgang Ackermann ◽  
Johan Van Vaerenbergh ◽  
...  
Keyword(s):  
Soil Samples ◽  
Pantoea Agglomerans ◽  
Open Reading Frames ◽  
Human Pathogen ◽  
Content Type ◽  
Host Diversity ◽  
Double Stranded Dna ◽  
Opportunistic Human Pathogen ◽  
Reading Frames

ABSTRACTPantoea agglomeransis a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. Bacteriophages LIMEzero and LIMElight ofP. agglomeransare lytic phages, isolated from soil samples, belonging to thePodoviridaeand are the firstPantoeaphages of this family to be described. The double-stranded DNA (dsDNA) genomes (43,032 bp and 44,546 bp, respectively) encode 57 and 55 open reading frames (ORFs). Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of theAutographivirinae, within the genus of the “phiKMV-like viruses.” Phylogenetic analysis of all the sequenced members of theAutographivirinaesupports the classification of phages LIMElight and LIMEzero as members of the “phiKMV-like viruses” and corroborates the subdivision into the different genera. These data expand the knowledge ofPantoeaphages and illustrate the wide host diversity of phages within the “phiKMV-like viruses.”

scholarly journals Strain variation in Bacillus cereus biofilms and their susceptibility to extracellular matrix-degrading enzymes

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245708
Author(s):  
Eun Seob Lim ◽  
Seung-Youb Baek ◽  
Taeyoung Oh ◽  
Minseon Koo ◽  
Joo Young Lee ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Bacillus Cereus ◽  
Biofilm Formation ◽  
Dnase I ◽  
Extracellular Dna ◽  
Proteinase K ◽  
Strain Variation ◽  
Protein Ratio ◽  
Degrading Enzymes ◽  
Matrix Degrading Enzymes

Bacillus cereus is a foodborne pathogen and can form biofilms on food contact surfaces, which causes food hygiene problems. While it is necessary to understand strain-dependent variation to effectively control these biofilms, strain-to-strain variation in the structure of B. cereus biofilms is poorly understood. In this study, B. cereus strains from tatsoi (BC4, BC10, and BC72) and the ATCC 10987 reference strain were incubated at 30°C to form biofilms in the presence of the extracellular matrix-degrading enzymes DNase I, proteinase K, dispase II, cellulase, amyloglucosidase, and α-amylase to assess the susceptibility to these enzymes. The four strains exhibited four different patterns in terms of biofilm susceptibility to the enzymes as well as morphology of surface-attached biofilms or suspended cell aggregates. DNase I inhibited the biofilm formation of strains ATCC 10987 and BC4 but not of strains BC10 and BC72. This result suggests that some strains may not have extracellular DNA, or their extracellular DNA may be protected in their biofilms. In addition, the strains exhibited different patterns of susceptibility to protein- and carbohydrate-degrading enzymes. While other strains were resistant, strains ATCC 10987 and BC4 were susceptible to cellulase, suggesting that cellulose or its similar polysaccharides may exist and play an essential role in their biofilm formation. Our compositional and imaging analyses of strains ATCC 10987 and BC4 suggested that the physicochemical properties of their biofilms are distinct, as calculated by the carbohydrate to protein ratio. Taken together, our study suggests that the extracellular matrix of B. cereus biofilms may be highly diverse and provides insight into the diverse mechanisms of biofilm formation among B. cereus strains.

scholarly journals Global transcriptome analysis of Stenotrophomonas maltophilia in response to growth at human body temperature

2021 ◽  
Vol 7 (7) ◽  
Author(s):  
Prashant P. Patil ◽  
Sanjeet Kumar ◽  
Amandeep Kaur ◽  
Samriti Midha ◽  
Kanika Bansal ◽  
...  
Keyword(s):  
Body Temperature ◽  
Human Body ◽  
Transcriptome Analysis ◽  
Stenotrophomonas Maltophilia ◽  
Type Species ◽  
Human Pathogen ◽  
Content Type ◽  
Link Type ◽  
Human Body Temperature ◽  
Opportunistic Human Pathogen

Stenotrophomonas maltophilia is a typical example of an environmental originated opportunistic human pathogen, which can thrive at different habitats including the human body and can cause a wide range of infections. It must cope with heat stress during transition from the environment to the human body as the physiological temperature of the human body (37 °C) is higher than environmental niches (22–30 °C). Interestingly, S. rhizophila a phylogenetic neighbour of S. maltophilia within genus Stenotrophomonas is unable to grow at 37 °C. Thus, it is crucial to understand how S. maltophilia is adapted to human body temperature, which could suggest its evolution as an opportunistic human pathogen. In this study, we have performed comparative transcriptome analysis of S. maltophilia grown at 28 and 37 °C as temperature representative for environmental niches and the human body, respectively. RNA-Seq analysis revealed several interesting findings showing alterations in gene-expression levels at 28 and 37 °C, which can play an important role during infection. We have observed downregulation of genes involved in cellular motility, energy production and metabolism, replication and repair whereas upregulation of VirB/D4 type IV secretion system, aerotaxis, cation diffusion facilitator family transporter and LacI family transcriptional regulators at 37 °C. Microscopy and plate assays corroborated altered expression of genes involved in motility. The results obtained enhance our understanding of the strategies employed by S. maltophilia during adaptation towards the human body.

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