Difference between revisions of "Micavibrio"

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{{Biorealm Genus}}
 
{{Biorealm Genus}}
 
==Classification==
 
==Classification==
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Bacteria; Proteobacteria; Deltaproteobacteria; Bdellovibrionales; Bdellovibrionaceae; Micavibrio
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Bacteria; Proteobacteria; Alphaproteobacteria; Bdellovibrionales; Bdellovibrionaceae; Micavibrio
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===Species===
 
===Species===
[[Image:mica.jpg‎|frame|right|150px|Scanning electron micrograph of ''Micavibrio aeruginosavorus'' (yellow) preying on ''Pseudomonas aeruginosa'' (purple) growing in a biofilm.  From  [http://www.umdnj.edu/research/publications/spring07/3.htm. The University of Virginia]]]
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[[Image:mica.jpg‎|frame|right|150px|Scanning electron micrograph of ''Micavibrio aeruginosavorus'' (yellow) preying on ''Pseudomonas aeruginosa'' (purple) growing in a biofilm.  From  [http://www.umdnj.edu/research/publications/spring07/3.htm. The University of Medicine and Dentistry of New Jersey]]]
 
    
 
    
 
''M. aeruginosavorus, M. admirandus''
 
''M. aeruginosavorus, M. admirandus''
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==Description and significance==
 
==Description and significance==
''Micavibrio aeruginosavorus'' is a predatory bacteria which displays ‘vampire-like’ behavior in an obligatory parasitic lifestyle on other bacteria. Gram-negative micro-organisms known to be pathogenic in humans, such as ''Pseudomonas aeruginosa'', are the prey for this host specific predator. ''M. aeruginosavorus''' life cycle consists of an attack phase, during which motile ''M. aeruginosavorus'' seek their prey, and an attachment phase, during which ''M. aeruginosavorus'' attach irreversibly to the cell surfaces of prey bacteria (4). The attached ''M. aeruginosavorus'' will feed on their prey and divide by binary fission, which leads to the death of the infected prey cells (4). By coculturing ''Bdellovibrio bacteriovorus'' 109J and ''M. aeruginosavorus'' ARL-13 with selected pathogens, [it has been] demonstrated that predatory bacteria are able to attack bacteria from the genus ''Acinetobacter, Aeromonas, Bordetella, Burkholderia, Citrobacter, Enterobacter, Escherichia, Klebsiella, Listonella, Morganella, Proteus, Pseudomonas, Salmonella, Serratia, Shigella, Vibrio'' and ''Yersinia'' (1). ''M. aeruginosavorus'' have an ability to prey and reduce many of the multidrug-resistant pathogens associated with human infection (1). The goal of researchers is to better understand the roles, capabilities, and interactions of ''M. aeruginosavorus'' as a potential 'live antibiotic' for the pathogens causing human disease.
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''Micavibrio spp.'' is an obligate predator that exhibits ‘vampire-like’ behavior.  It attaches to the surfaces of prey and feeds by "leaching", eventually killing its prey.  They prey on Gram-negative micro-organisms known to be pathogenic in humans. <sup>4</sup>  Due to its epibiotic lifestyle, obtaining an axenic culture is difficult, limiting potenial research.  Currently, research is focused in its application as an antimicrobial.<sup>1</sup>
  
 
==Genome structure==
 
==Genome structure==
[[Image:chromosome.jpg|thumb|400px|right| Decription ''bacteria''. [http://www.biomedcentral.com/1471-2164/12/453 From BMC Genomics.]]]
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[[Image:chromosome.jpg|thumb|400px|right| ''Micavibrio aerurinosavorus'' ARL-13 genome. [http://www.biomedcentral.com/1471-2164/12/453 From BMC Genomics.]]]
  
The genome of ''M. aeruginosavorus'' ARL-13 has been completely sequenced and is 2,481,983 bp long on a single circular molecule with a G+C content of 54% (4). 90.3% of the genome is predicted to code for 2,434 open-reading frames, 40 tRNA genes and one rRNA operon (4). No extragenomic DNA molecules (phage or plasmid) were identified from the sequence and there was a complete absence of mobile genetic elements including insertion sequences, transposons and retrotransposons (4). Nine genomic islands encode multiple genes important for predator-prey interaction (hemolysin-related proteins) (4). RNA-Seq analysis has shown a substantial difference in transcriptome between the attack phase (seeking prey) and attachment phase (feeding on prey and replicating) (4). ''M. aeruginosavorus'' encodes six hemolysin related proteins belonging to the RTX family of toxins (following secretion, hemolysin inserts into the host cell membrane, forms a transmembrane pore then lyses the host cell) (4). The genome of ''M. aeruginosavorus'' is moderate in size, at 2.4 Mbp, it is almost twice the size of most obligate intracellular alpha-proteobacteria (4). It is substantially smaller than most free-living alpha-proteobacteria, and about 35% smaller than ''B. bacteriovorus'' HD100, which is 3.7 Mbp (4). The genome also encodes an impressive selection of hydrolytic enzymes with 4.3% of the genome predicting to encode 49 peptidases and proteases, 12 lipases, 4 RNAses, 2 DNAses and 37 additional hydrolases (4).
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The genome of ''M. aeruginosavorus'' ARL-13 has been completely sequenced and is a single circular molecule consisting of 2,481,983 bp and a 54.7% G+C content.<sup>4</sup> It is predicted that 90.3% of the genome codes for 1 rRNA operon, 40 tRNA genes and 2,434 open reading frames (ORFs). <sup>4</sup> There were no extragenomic DNA molecules (phage or plasmid) identified from the sequence and there was a complete absence of mobile genetic elements including insertion sequences, transposons and retrotransposons.<sup>4</sup> Numerous genes are encoded which have an important role in predator-prey interaction, for example, hemolysin-related proteins.<sup>4</sup> RNA-Seq analysis has shown a substantial difference in transcriptome between the attack phase (seeking prey) and attachment phase (feeding on prey and replicating). <sup>4</sup> ''M. aeruginosavorus'' ARL-13 encodes six hemolysin related proteins belonging to the RTX family of toxins which are suggested to contribute to recognizing and adhering to prey.<sup>4</sup> The genome of ''M. aeruginosavorus'' ARL-13 is a moderate size at 2.4 Mbp and is almost twice the size of most obligatory intracellular alphaproteobacteria and is smaller, by comparison, to most free living alphaproteobacteria.<sup>4</sup> The genome also encodes a large selection of hydrolytic enzymes with 4.3% of the genome predicting to encode 49 peptidases and proteases, 12 lipases, 4 RNAses, 2 DNAses and 37 additional hydrolases.<sup>4</sup>  The genome of ''M. admirandus'' ARL-14 has a G+C content of 57.1%.<sup>5</sup>
  
 
==Cell and colony structure==
 
==Cell and colony structure==
''M aeruginosavorus'' was first isolated in wastewater. ''M. aeruginosavorus'' belongs to the delta subgroup of proteobacteria; they are small (0.5 to 1.5 μm long), rod shaped, and curved and have a single polar flagellum (2).  Replication is via binary fission, producing one daughter cell at a time. ''M. aeruginosavorus'' will form plaques in diluted nutrient broth agar.
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''Micaviobrio spp.'' are curved rods measuring from 0.5 to 1.5 μm long and possess a single, unsheathed, polar flagellum.<sup>2</sup> Replication is via binary fission and is dependent on prey.<sup>4</sup>  Because ''Micavibrio spp.'' are free living obligate parasites, they are maintained as plaques on double-layered, diluted nutrient broth agar. Optimal growth conditions are in an aerobic environment in temperatures ranging from 25 to 37ºC.<sup>[1]</sup>
  
 
==Metabolism==
 
==Metabolism==
Despite being an obligate predator depending on prey for replication, ''M. aeruginosavorus'' encodes almost all major metabolic pathways (4). Genome analysis suggests that there are multiple amino acids that it can neither make nor import directly from the environment, thus providing a simple explanation for its strict dependence on prey (4). Genome analysis also show many free-living bacterium features such as genes involved in lipopolysaccharide and cell wall biosynthesis, glycolysis, TCA cycle, electron transport chain, ATP synthase (indication of ATP generation), respiration systems (4). It also contains a pentose phosphate pathway and a full set of genes for the metabolism of nucleotides (4). ''M. aeruginosavorus'' encodes genes for the synthesis of 13 amino acids necessary for protein synthesis but is missing the biosynthesis pathways for the remaining 7 amino acids (Alanine, Arginine, Histidine, Isoleucine, Methionine, Tryptophan and Valine) (4). The genome is also missing transporters for amino acids, peptides and amines, which ''M. aeruginosavorus'' obtains from its prey (4).
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Although ''M. aeruginosavorus'' depends on prey for replication, the genome encodes for most of the major metabolic pathways.<sup>4</sup> Analysis of the genome suggests there are numerous amino acids that ''M. aeruginosavorus'' can neither make nor assimilate directly from the environment, which explains the prey dependency.<sup>4</sup> Genome analysis also show many free-living bacterium features such as genes involved in lipopolysaccharide and cell wall biosynthesis, glycolysis, TCA cycle, electron transport chain, ATP synthase (indication of ATP generation) and respiration systems.<sup>4</sup> It also contains a pentose phosphate pathway and a full set of genes for the metabolism of nucleotides.<sup>4</sup> While ''M. aeruginosavorus'' encodes the genes for the synthesis of 13 amino acids necessary for protein synthesis, it is missing the biosynthesis pathways for the remaining 7 amino acids (Alanine, Arginine, Histidine, Isoleucine, Methionine, Tryptophan and Valine).<sup>4</sup>  The genome is also missing transporters for amino acids, peptides and amines, which ''M. aeruginosavorus'' obtains from its prey.<sup>4</sup>
  
 
==Ecology==
 
==Ecology==
Experiments show optimal conditions under which ''M. aeruginosavorus'' was able to prey were temperatures ranging from 25 to 37ºC with an aerobic environment (1). Predation was shown to halt under microaerophilic and anaerobic conditions (1).
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To date, ''Micavibrio spp.'' have only been isolated from waste water.  The life cycle of ''Micavibrio spp.''' is characterized by an attack phase and an attachment phase.<sup>4</sup> During the attack phase ''Micavibrio spp.'' are motile and actively seek prey.<sup>4</sup> During the attachment phase ''Micavibrio spp.'' irreversibly attach to the cell surface of prey, feed, and divide via binary fission, eventually killing the prey.<sup>4</sup>  Oringinally, both species exhibited high specificity for prey, ''M. aeruginosavorus'' for ''Pseudomonas aeruginosa'' and ''M. admirandus'' for ''Stenotrophomonas maltophilia''.<sup>5</sup>  However, more recently they both have been shown to prey on a broad range of Gram-negative bacteria when stored in suboptimal conditions.<sup>3</sup>
  
 
==Pathology==
 
==Pathology==
How does this organism cause disease? Human, animal, plant hosts? Virulence factors.
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''Micavibrio spp.'' have not been shown to be pathogenic to humans.  Current research is exploring ''M. aeruginosavorus'' potential use as an antimicrobial against increasingly more drug-resistant Gram-negative pathogenic bacteria.  Pathogens are up to 1000 times more drug resistant to traditional microbial agents when forming biofilms.  It has been shown that biofilms offer no additional protection to the prey of ''M. aeruginosavorus''.  Furture research involves the use of ''M. aeruginosavorus'' as a potential "live antibiotic".<sup>[3]</sup>
  
 
==References==
 
==References==
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[http://www.ncbi.nlm.nih.gov/pubmed/21114596 1] Dashiff, A., Junka, R., Libera, M. and Kadouri, D. (2011), Predation of human pathogens by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus. Journal of Applied Microbiology, 110: 431–444. doi: 10.1111/j.1365-2672.2010.04900.x
 
[http://www.ncbi.nlm.nih.gov/pubmed/21114596 1] Dashiff, A., Junka, R., Libera, M. and Kadouri, D. (2011), Predation of human pathogens by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus. Journal of Applied Microbiology, 110: 431–444. doi: 10.1111/j.1365-2672.2010.04900.x
  
[http://www.ncbi.nlm.nih.gov/pubmed/21808652 2] Dashiff, A., Keeling, T., & Kadouri, D. (2011). Inhibition of predation by Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus via host cell metabolic activity in the presence of carbohydrates. Applied & Environmental Microbiology, 77(7), 2224-2231. doi: 10.1128/.02565-10
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[http://www.ncbi.nlm.nih.gov/pubmed/21317250 2] Dashiff, A., Keeling, T., & Kadouri, D. (2011). Inhibition of predation by Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus via host cell metabolic activity in the presence of carbohydrates. Applied & Environmental Microbiology, 77(7), 2224-2231. doi: 10.1128/.02565-10
 +
 
 +
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1796979/ 3]. Kadouri, Daniel, Nel C. Venzon, and George A. O’Toole. Vulnerability of Pathogenic Biofilms to Micavibrio aeruginosavorus. Applied and Environmental Microbiology. 73.2 (2007): 605-14. doi:10.1128/AEM.01893-06
 +
 
 +
[http://www.ncbi.nlm.nih.gov/pubmed/21936919 4] Wang, Z.; Kadouri, D. E.; Wu, M. (2011). "Genomic insights into an obligate epibiotic bacterial predator: Micavibrio aeruginosavorus ARL-13". BMC Genomics 12: 453. doi:10.1186/1471-2164-12-453
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[http://www.springerlink.com.ursus-proxy-1.ursus.maine.edu/content/u52102/ 5] Brenner, D. J., Krieg, N. R., Garrity, G. M., Staley, J. T., Boone, D. R., Vos, P. D., Goofellow, M., Rainey, F.A., & Schliefer, K. H. (2005). Bergey's Manual of Systematic Bacteriology: Vol. 2. The Proteobacteria Part C The Alpha-, Beta-, Delta-, and Epsilonproteobacteria. 
  
[http://www.ncbi.nlm.nih.gov/pubmed/21808652 3]. Kadouri, Daniel, Nel C. Venzon, and George A. O’Toole. Vulnerability of Pathogenic Biofilms to Micavibrio aeruginosavorus. Applied and Environmental Microbiology. 73.2 (2007): 605-14. doi:10.1128/AEM.01893-06
 
  
[http://www.ncbi.nlm.nih.gov/pubmed/21808652 4] Wang, Z.; Kadouri, D. E.; Wu, M. (2011). "Genomic insights into an obligate epibiotic bacterial predator: Micavibrio aeruginosavorus ARL-13". BMC Genomics 12: 453. doi:10.1186/1471-2164-12-453
 
  
  
  
 
Edited by Kelly Gordon and Jennifer Willis, students of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences, http://www.usm.maine.edu/bio
 
Edited by Kelly Gordon and Jennifer Willis, students of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences, http://www.usm.maine.edu/bio

Latest revision as of 15:40, 22 February 2016

This student page has not been curated.

A Microbial Biorealm page on the genus Micavibrio

Classification

Higher order taxa

Bacteria; Proteobacteria; Alphaproteobacteria; Bdellovibrionales; Bdellovibrionaceae; Micavibrio

Species

Scanning electron micrograph of Micavibrio aeruginosavorus (yellow) preying on Pseudomonas aeruginosa (purple) growing in a biofilm. From The University of Medicine and Dentistry of New Jersey

M. aeruginosavorus, M. admirandus

NCBI: Taxonomy Genomes

Description and significance

Micavibrio spp. is an obligate predator that exhibits ‘vampire-like’ behavior. It attaches to the surfaces of prey and feeds by "leaching", eventually killing its prey. They prey on Gram-negative micro-organisms known to be pathogenic in humans. 4 Due to its epibiotic lifestyle, obtaining an axenic culture is difficult, limiting potenial research. Currently, research is focused in its application as an antimicrobial.1

Genome structure

Micavibrio aerurinosavorus ARL-13 genome. From BMC Genomics.

The genome of M. aeruginosavorus ARL-13 has been completely sequenced and is a single circular molecule consisting of 2,481,983 bp and a 54.7% G+C content.4 It is predicted that 90.3% of the genome codes for 1 rRNA operon, 40 tRNA genes and 2,434 open reading frames (ORFs). 4 There were no extragenomic DNA molecules (phage or plasmid) identified from the sequence and there was a complete absence of mobile genetic elements including insertion sequences, transposons and retrotransposons.4 Numerous genes are encoded which have an important role in predator-prey interaction, for example, hemolysin-related proteins.4 RNA-Seq analysis has shown a substantial difference in transcriptome between the attack phase (seeking prey) and attachment phase (feeding on prey and replicating). 4 M. aeruginosavorus ARL-13 encodes six hemolysin related proteins belonging to the RTX family of toxins which are suggested to contribute to recognizing and adhering to prey.4 The genome of M. aeruginosavorus ARL-13 is a moderate size at 2.4 Mbp and is almost twice the size of most obligatory intracellular alphaproteobacteria and is smaller, by comparison, to most free living alphaproteobacteria.4 The genome also encodes a large selection of hydrolytic enzymes with 4.3% of the genome predicting to encode 49 peptidases and proteases, 12 lipases, 4 RNAses, 2 DNAses and 37 additional hydrolases.4 The genome of M. admirandus ARL-14 has a G+C content of 57.1%.5

Cell and colony structure

Micaviobrio spp. are curved rods measuring from 0.5 to 1.5 μm long and possess a single, unsheathed, polar flagellum.2 Replication is via binary fission and is dependent on prey.4 Because Micavibrio spp. are free living obligate parasites, they are maintained as plaques on double-layered, diluted nutrient broth agar. Optimal growth conditions are in an aerobic environment in temperatures ranging from 25 to 37ºC.[1]

Metabolism

Although M. aeruginosavorus depends on prey for replication, the genome encodes for most of the major metabolic pathways.4 Analysis of the genome suggests there are numerous amino acids that M. aeruginosavorus can neither make nor assimilate directly from the environment, which explains the prey dependency.4 Genome analysis also show many free-living bacterium features such as genes involved in lipopolysaccharide and cell wall biosynthesis, glycolysis, TCA cycle, electron transport chain, ATP synthase (indication of ATP generation) and respiration systems.4 It also contains a pentose phosphate pathway and a full set of genes for the metabolism of nucleotides.4 While M. aeruginosavorus encodes the genes for the synthesis of 13 amino acids necessary for protein synthesis, it is missing the biosynthesis pathways for the remaining 7 amino acids (Alanine, Arginine, Histidine, Isoleucine, Methionine, Tryptophan and Valine).4 The genome is also missing transporters for amino acids, peptides and amines, which M. aeruginosavorus obtains from its prey.4

Ecology

To date, Micavibrio spp. have only been isolated from waste water. The life cycle of Micavibrio spp.' is characterized by an attack phase and an attachment phase.4 During the attack phase Micavibrio spp. are motile and actively seek prey.4 During the attachment phase Micavibrio spp. irreversibly attach to the cell surface of prey, feed, and divide via binary fission, eventually killing the prey.4 Oringinally, both species exhibited high specificity for prey, M. aeruginosavorus for Pseudomonas aeruginosa and M. admirandus for Stenotrophomonas maltophilia.5 However, more recently they both have been shown to prey on a broad range of Gram-negative bacteria when stored in suboptimal conditions.3

Pathology

Micavibrio spp. have not been shown to be pathogenic to humans. Current research is exploring M. aeruginosavorus potential use as an antimicrobial against increasingly more drug-resistant Gram-negative pathogenic bacteria. Pathogens are up to 1000 times more drug resistant to traditional microbial agents when forming biofilms. It has been shown that biofilms offer no additional protection to the prey of M. aeruginosavorus. Furture research involves the use of M. aeruginosavorus as a potential "live antibiotic".[3]

References

1 Dashiff, A., Junka, R., Libera, M. and Kadouri, D. (2011), Predation of human pathogens by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus. Journal of Applied Microbiology, 110: 431–444. doi: 10.1111/j.1365-2672.2010.04900.x

2 Dashiff, A., Keeling, T., & Kadouri, D. (2011). Inhibition of predation by Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus via host cell metabolic activity in the presence of carbohydrates. Applied & Environmental Microbiology, 77(7), 2224-2231. doi: 10.1128/.02565-10

3. Kadouri, Daniel, Nel C. Venzon, and George A. O’Toole. Vulnerability of Pathogenic Biofilms to Micavibrio aeruginosavorus. Applied and Environmental Microbiology. 73.2 (2007): 605-14. doi:10.1128/AEM.01893-06

4 Wang, Z.; Kadouri, D. E.; Wu, M. (2011). "Genomic insights into an obligate epibiotic bacterial predator: Micavibrio aeruginosavorus ARL-13". BMC Genomics 12: 453. doi:10.1186/1471-2164-12-453

5 Brenner, D. J., Krieg, N. R., Garrity, G. M., Staley, J. T., Boone, D. R., Vos, P. D., Goofellow, M., Rainey, F.A., & Schliefer, K. H. (2005). Bergey's Manual of Systematic Bacteriology: Vol. 2. The Proteobacteria Part C The Alpha-, Beta-, Delta-, and Epsilonproteobacteria.



Edited by Kelly Gordon and Jennifer Willis, students of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences, http://www.usm.maine.edu/bio