Bacteriophage can drive virulence in marine pathogens

2020 ◽  
pp. 73-82 ◽  
Author(s):  
Mark Little ◽  
Maria Isabel Rojas ◽  
Forest Rohwer
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Pathogens ◽  
Meta Analysis ◽  
Relevant Literature ◽  
Marine Ecosystems ◽  
Marine Environments ◽  
Human Pathogens ◽  
Large Role ◽  
Associated Bacteria ◽  
And Function

The roles of prophages in disease have mainly considered human pathogens, while their role in marine pathogens has only recently been considered. This chapter reviews the relevant literature on what is known of prophages in marine ecosystems and provides a meta-analysis of the abundance and function of prophages in marine pathogenic bacteria. According to these results, bacterial pathogens in marine environments contain a significantly higher abundance of prophage DNA in their genomes than host-associated bacteria, which are non-pathogenic. The authors also surveyed the genetic content of the prophages that were associated with known pathogens and compared their functions to non-pathogens. Their findings suggest that horizontally acquired prophage-encoded DNA may play a large role in the ecology and evolution of marine diseases

scholarly journals Molybdenum Enzymes and How They Support Virulence in Pathogenic Bacteria

2020 ◽  
Vol 11 ◽  
Author(s):  
Qifeng Zhong ◽  
Bostjan Kobe ◽  
Ulrike Kappler
Keyword(s):  
Drug Targets ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogens ◽  
Energy Generation ◽  
Cellular Functions ◽  
Pathogen Fitness ◽  
Future Drug ◽  
Domains Of Life ◽  
Cofactor Biosynthesis ◽  
And Function

Mononuclear molybdoenzymes are highly versatile catalysts that occur in organisms in all domains of life, where they mediate essential cellular functions such as energy generation and detoxification reactions. Molybdoenzymes are particularly abundant in bacteria, where over 50 distinct types of enzymes have been identified to date. In bacterial pathogens, all aspects of molybdoenzyme biology such as molybdate uptake, cofactor biosynthesis, and function of the enzymes themselves, have been shown to affect fitness in the host as well as virulence. Although current studies are mostly focused on a few key pathogens such as Escherichia coli, Salmonella enterica, Campylobacter jejuni, and Mycobacterium tuberculosis, some common themes for the function and adaptation of the molybdoenzymes to pathogen environmental niches are emerging. Firstly, for many of these enzymes, their role is in supporting bacterial energy generation; and the corresponding pathogen fitness and virulence defects appear to arise from a suboptimally poised metabolic network. Secondly, all substrates converted by virulence-relevant bacterial Mo enzymes belong to classes known to be generated in the host either during inflammation or as part of the host signaling network, with some enzyme groups showing adaptation to the increased conversion of such substrates. Lastly, a specific adaptation to bacterial in-host survival is an emerging link between the regulation of molybdoenzyme expression in bacterial pathogens and the presence of immune system-generated reactive oxygen species. The prevalence of molybdoenzymes in key bacterial pathogens including ESKAPE pathogens, paired with the mounting evidence of their central roles in bacterial fitness during infection, suggest that they could be important future drug targets.

scholarly journals Dissecting the co-transcriptome landscape of plants and microbiota members

2021 ◽  
Author(s):  
Tatsuya Nobori ◽  
Yu Cao ◽  
Frederickson Entila ◽  
Eik Dahms ◽  
Yayoi Tsuda ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Early Stage ◽  
Building Blocks ◽  
Niche Separation ◽  
In Planta ◽  
Bacterial Strains ◽  
Transcriptional Responses ◽  
Associated Bacteria ◽  
Plant Microbiota ◽  
And Function

AbstractInteractions between plants and each neighboring microbial species are fundamental building blocks that collectively determine the structure and function of the plant microbiota, but the molecular basis of such interactions is poorly characterized. Here, we monocolonized Arabidopsis leaves with nine plant-associated bacteria from all major phyla of the plant microbiota and profiled co-transcriptomes of plants and bacteria. These strains elicited quantitatively different plant transcriptional responses including typical pattern-triggered immunity responses. Genes of non-pathogenic bacteria involved in general metabolism and energy production were commonly suppressed in planta in contrast to a virulent pathogen. Various nutrient acquisition pathways that are frequently encoded in the genomes of plant-associated bacteria were induced in planta in a strain-specific manner, shedding light on bacterial adaptation to the plant environment and identifying a potential driving force of niche separation. Integrative analyses of plant and bacterial transcriptomes suggested that the transcriptional reprogramming of plants is largely uncoupled from that of bacteria at an early stage of interactions. This study provides insights into how plants discriminate among bacterial strains and sets the foundation for in-depth mechanistic dissection of plant-microbiota interactions.

scholarly journals The Divided Bacterial Genome: Structure, Function, and Evolution

2017 ◽  
Vol 81 (3) ◽  
Author(s):  
George C. diCenzo ◽  
Turlough M. Finan
Keyword(s):  
Meta Analysis ◽  
Bacterial Genome ◽  
Genome Structure ◽  
Dna Molecules ◽  
Human Pathogens ◽  
Genome Sequences ◽  
Bacterial Genomes ◽  
Content Type ◽  
A Genome ◽  
And Function

SUMMARY Approximately 10% of bacterial genomes are split between two or more large DNA fragments, a genome architecture referred to as a multipartite genome. This multipartite organization is found in many important organisms, including plant symbionts, such as the nitrogen-fixing rhizobia, and plant, animal, and human pathogens, including the genera Brucella, Vibrio, and Burkholderia. The availability of many complete bacterial genome sequences means that we can now examine on a broad scale the characteristics of the different types of DNA molecules in a genome. Recent work has begun to shed light on the unique properties of each class of replicon, the unique functional role of chromosomal and nonchromosomal DNA molecules, and how the exploitation of novel niches may have driven the evolution of the multipartite genome. The aims of this review are to (i) outline the literature regarding bacterial genomes that are divided into multiple fragments, (ii) provide a meta-analysis of completed bacterial genomes from 1,708 species as a way of reviewing the abundant information present in these genome sequences, and (iii) provide an encompassing model to explain the evolution and function of the multipartite genome structure. This review covers, among other topics, salient genome terminology; mechanisms of multipartite genome formation; the phylogenetic distribution of multipartite genomes; how each part of a genome differs with respect to genomic signatures, genetic variability, and gene functional annotation; how each DNA molecule may interact; as well as the costs and benefits of this genome structure.

scholarly journals Clearance of Gram-Negative Bacterial Pathogens from the Ocular Surface by Predatory Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 810
Author(s):  
Eric G. Romanowski ◽  
Shilpi Gupta ◽  
Androulla Pericleous ◽  
Daniel E. Kadouri ◽  
Robert M. Q. Shanks
Keyword(s):  
Ocular Surface ◽  
Pathogenic Bacteria ◽  
Contact Lenses ◽  
Bacterial Pathogens ◽  
Time Intervals ◽  
Antibiotic Resistant ◽  
Associated Bacteria ◽  
Gram Negative ◽  
Predatory Bacteria ◽  
Rapid Clearance

It was previously demonstrated that predatory bacteria are able to efficiently eliminate Gram-negative pathogens including antibiotic-resistant and biofilm-associated bacteria. In this proof-of-concept study we evaluated whether two species of predatory bacteria, Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus, were able to alter the survival of Gram-negative pathogens on the ocular surface. Clinical keratitis isolates of Pseudomonas aeruginosa (strain PAC) and Serratia marcescens (strain K904) were applied to the ocular surface of NZW rabbits followed by application of predatory bacteria. At time intervals, surviving pathogenic bacteria were enumerated. In addition, B. bacteriovorus and S. marcescens were applied to porcine organ culture corneas under contact lenses, and the ocular surface was examined by scanning electron microscopy. The ocular surface epithelial layer of porcine corneas exposed to S. marcescens, but not B. bacteriovorus was damaged. Using this model, neither pathogen could survive on the rabbit ocular surface for longer than 24 h. M. aeruginosavorus correlated with a more rapid clearance of P. aeruginosa but not S. marcescens from rabbit eyes. This study supports previous evidence that predatory bacteria are well tolerated by the cornea, but suggest that predatory bacteria do not considerably change the ability of the ocular surface to clear the tested Gram-negative bacterial pathogens from the ocular surface.

scholarly journals Cladophora (Chlorophyta) spp. Harbor Human Bacterial Pathogens in Nearshore Water of Lake Michigan

2006 ◽  
Vol 72 (7) ◽  
pp. 4545-4553 ◽  
Author(s):  
Satoshi Ishii ◽  
Tao Yan ◽  
Dawn A. Shively ◽  
Muruleedhara N. Byappanahalli ◽  
Richard L. Whitman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Lake Michigan ◽  
Bacterial Pathogens ◽  
Dna Fingerprint ◽  
Most Probable Number ◽  
Cladophora Glomerata ◽  
Human Pathogens ◽  
Potential Health ◽  
Probable Number

ABSTRACT Cladophora glomerata, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently, Cladophora has been shown to harbor high densities of the fecal indicator bacteria Escherichia coli and enterococci. Cladophora may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attached Cladophora, obtained from the Lake Michigan and Burns Ditch (Little Calumet River, Indiana) sides of a breakwater during the summers of 2004 and 2005, harbored the bacterial pathogens Shiga toxin-producing Escherichia coli (STEC), Salmonella, Shigella, and Campylobacter. The presence of potential pathogens and numbers of organisms were determined by using cultural methods and by using conventional PCR, most-probable-number PCR (MPN-PCR), and quantitative PCR (QPCR) performed with genus- and toxin-specific primers and probes. While Shigella and STEC were detected in 100% and 25%, respectively, of the algal samples obtained near Burns Ditch in 2004, the same pathogens were not detected in samples collected in 2005. MPN-PCR and QPCR allowed enumeration of Salmonella in 40 to 80% of the ditch- and lakeside samples, respectively, and the densities were up to 1.6 × 103 cells per g Cladophora. Similarly, these PCR methods allowed enumeration of up to 5.4 × 102 Campylobacter cells/g Cladophora in 60 to 100% of lake- and ditchside samples. The Campylobacter densities were significantly higher (P < 0.05) in the lakeside Cladophora samples than in the ditchside Cladophora samples. DNA fingerprint analyses indicated that genotypically identical Salmonella isolates were associated with geographically and temporally distinct Cladophora samples. However, Campylobacter isolates were genetically diverse. Since animal hosts are thought to be the primary habitat for Campylobacter and Salmonella species, our results suggest that Cladophora is a likely secondary habitat for pathogenic bacteria in Lake Michigan and that the association of these bacteria with Cladophora warrants additional studies to assess the potential health impact on beach users.

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

The ENIGMA Brain Injury Working Group: Approach, Challenges, and Potential Benefits

2019 ◽  
Author(s):  
Elisabeth A. Wilde ◽  
Emily L. Dennis ◽  
David F Tate
Keyword(s):  
Brain Injury ◽  
Working Group ◽  
Meta Analysis ◽  
Special Issue ◽  
Group Approach ◽  
Challenges And Opportunities ◽  
Brain Structure And Function ◽  
Potential Benefits ◽  
And Function ◽  
Neuroimaging Genetics

The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) consortium brings together researchers from around the world to try to identify the genetic underpinnings of brain structure and function, along with robust, generalizable effects of neurological and psychiatric disorders. The recently-formed ENIGMA Brain Injury working group includes 8 subgroups, based largely on injury mechanism and patient population. This introduction to the special issue summarizes the history, organization, and objectives of ENIGMA Brain Injury, and includes a discussion of strategies, challenges, opportunities and goals common across 6 of the subgroups under the umbrella of ENIGMA Brain Injury. The following articles in this special issue, including 6 articles from different subgroups, will detail the challenges and opportunities specific to each subgroup.

scholarly journals TO STUDY THE ANTIBACTERIAL ACTIVITY OF VARIOUS EXTRACTS OF CLAUSENA DENTATA (WILLD.) ROEM.

2019 ◽  
pp. 69-73
Author(s):  
ANNAMALAI MADURAM ◽  
RAJU KAMARAJ
Keyword(s):  
Antibacterial Activity ◽  
Tamil Nadu ◽  
Pathogenic Bacteria ◽  
Volatile Oil ◽  
Stem Bark ◽  
Salmonella Typhi ◽  
Chloroform Extract ◽  
Klebsiella Pneumonia ◽  
Human Pathogens ◽  
Human Pathogenic Bacteria

Objectives: The objectives of the study were to study the antibacterial activity for the various extracts of Clausena dentata against human pathogens. Clausena (Rutaceae) is a genus of about 23 species of unarmed trees and shrubs. The stem bark of C. dentata is used in veterinary medicine for the treatment of wounds and sprains. Even though C. dentata has a lot of potential medical uses, the study of microbiological properties is very scarce. Methods: The plant C. dentata was collected from Kadagaman, near Tiruvannamalai, Tamil Nadu, India, and authenticated by Centre for Advanced Study in Botany, University of Madras, Chennai. The dry powder of stem bark was extracted with hexane, chloroform, and methanol. The extracts were subjected to qualitative phytochemical screening and antibacterial activity against human pathogenic bacteria such as Escherichia coli, Salmonella Typhi, Klebsiella pneumonia, Vibrio cholerae, and Staphylococcus aureus and compared with ciprofloxacin. Results: Qualitative chemical tests revealed the presence of various phytochemicals such as alkaloids, glycosides, carbohydrate, proteins and amino acids, phytosterols, and volatile oil. The antibacterial activity result reveals that all the extracts were are more active against V. cholerae. The activity against Pseudomonas aeruginosa was mild. Conclusion: The activity against V. cholerae was comparable with that of 5 μg/mL ciprofloxacin at the concentration of C. dentata 40 μg/mL. The orders of antibacterial activity against human pathogenic bacteria are hexane, methanol, and chloroform extract of C. dentata.

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