Difference between revisions of "Bordetella bronchiseptica"

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(Description and significance)
(Cell structure and metabolism)
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==Cell structure and metabolism==
 
==Cell structure and metabolism==
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
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Bordetella bronchiseptica may or may not have a flagella dependent on if environment stimuli signals for need of motility. When present, the flagella is most commonly observed to be a left-handed triple helix with an average diameter of approximately 13.8 nm. In some cases, the flagella may be up to 18 to 22 nm thick, consisting of braided structures of 5 to 6 individual strands. [5]
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Other unique structures include a 5-layered cell wall. The first 3 layers give the organism a lobulated surface contour appearance. The walls have channels between the lobules which are within a 10-20nm wide range. [6]
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The inner cell membrane which surrounds the cytoplasm is tri-laminar. Inside, the cytoplasm matrix is rich in ribosomes. [9] The nuclear zone of Bordetella bronchiseptica contains DNA present in a network of fibers and undefined bodies. The whole organism seems to be encapsulated in a polysaccharide capsule [6], enabling it to survive in the environment whereas its two closest relatives which lack the capsule cannot. The organism seems also to contain genes that encode pili.
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While its genome does encode complete pathways for biosynthesis of needed intermediates, Bordetella bronchiseptica and the genus Bordetella in general do not use sugars as a carbon source. As expected, the genes encoding for enzymes normally present in this pathway (such as phosophofructokinase, glucokinase, fructose1,6-bisphophate, etc.) are absent form the genome. However, genes encoding the gluconeogenesis are present, suggesting that sugars such as glucose can be made. Though genes are present that encode for the TCA cycle are present, it is believed to be non-functional from a study’s observations in which Acetyl-Coenzyme A and oxaloacetate did not give rise to alpha-ketoglutarate. [5] This may be due to an evolutionary remnant.
  
 
==Ecology==
 
==Ecology==

Revision as of 06:55, 5 June 2007

Bordetella bronchiseptica A Microbial Biorealm page on the genus Bordetella bronchiseptica

Classification

Higher order taxa

Domain; Phylum; Class; Order; family [Others may be used. Use NCBI link to find]

Species

NCBI: Taxonomy

Genus species

Bordetella bronchiseptica


Bordetella bronchiseptica is a minute, gram-negative rod-shaped coccobacilli about .5-1 micrometers in diameter and 5 micrometers in length. It may or may not have a flagella, dependent on environmental stimuli. Optimal growth temperature is 35-37° C. [4] Though it is commonly known to colonize in respiratory tracts of animals, it can also withstand surviving long-term in the environment, a trait that separates it from its most common relatives (noted below). It can also be cultured on various media and has demonstrated rapid growth on blood-free peptone agar. [1,4]

This aerobic species was first isolated and identified by Ferry in 1910 as Bacillus bronchicanis, recovered from respiratory tracts of dogs infected with distemper. Ferry also isolated it later (1912-1913) from the respiratory tracts of guinea pigs, monkeys, and other animals and subsequently changed the name to Bacillus bronchiseptica. The organism would go through at least four more name changes before Moreno-Lopez founded and described the genus Bordetella (After the first man to isolate the pertussis-causing organism, Jules Bordet). The name was then settled to be Bordetella bronchiseptica. [4,9] Bordetella bronchiseptica is mostly closely related to Bordetella pertussis and Bordetella parapertussis, both of which is believed to have risen originally from Bordtella bronchiseptica. It is believed that the species diverged 3.5 million years ago through decay of the Bordetella brochiseptica genome, as seen through a large-scale gene loss of the two subsequent species. [1,9] Due to its effect on mammals such as domestic pets (cats and dogs) and lab animals, Bordetella bronchiseptica has been closely studied. It has also had its genome sequenced, primarily to derive data in comparison to its relative Bordetella pertussis, which causes whooping cough in humans. [9]

Genome structure

Bordetella bronchiseptica has a circular chromosome consisting of approximately 5,338,400 base pairs. It has one or more medium to large-sized plasmids dependent on the strain, and it is unknown at the time if these encode for anything useful. A small labile plasmid is found in most strains and is believed to be crucial in inferred antibiotic resistance. Of the circular chromosome, 68.07% of the composition are GC complements. It is believed to have 5,007 coding sequences with an average gene size of 978 base pairs. There are 3 rRNA operons as well as 55 tRNA operons. Analysis of the genome shows that there has been horizontal DNA transfer as apparent by the anomalous GC content. About 3,000 genes are shared by its closest relatives, B.pertussis and B. parapertussis. Its larger genome size compared to B. pertussis and B. parapertussis is believed to be crucial in coding for extra features suce as its capsule.[9]

Cell structure and metabolism

Bordetella bronchiseptica may or may not have a flagella dependent on if environment stimuli signals for need of motility. When present, the flagella is most commonly observed to be a left-handed triple helix with an average diameter of approximately 13.8 nm. In some cases, the flagella may be up to 18 to 22 nm thick, consisting of braided structures of 5 to 6 individual strands. [5] Other unique structures include a 5-layered cell wall. The first 3 layers give the organism a lobulated surface contour appearance. The walls have channels between the lobules which are within a 10-20nm wide range. [6]

The inner cell membrane which surrounds the cytoplasm is tri-laminar. Inside, the cytoplasm matrix is rich in ribosomes. [9] The nuclear zone of Bordetella bronchiseptica contains DNA present in a network of fibers and undefined bodies. The whole organism seems to be encapsulated in a polysaccharide capsule [6], enabling it to survive in the environment whereas its two closest relatives which lack the capsule cannot. The organism seems also to contain genes that encode pili. While its genome does encode complete pathways for biosynthesis of needed intermediates, Bordetella bronchiseptica and the genus Bordetella in general do not use sugars as a carbon source. As expected, the genes encoding for enzymes normally present in this pathway (such as phosophofructokinase, glucokinase, fructose1,6-bisphophate, etc.) are absent form the genome. However, genes encoding the gluconeogenesis are present, suggesting that sugars such as glucose can be made. Though genes are present that encode for the TCA cycle are present, it is believed to be non-functional from a study’s observations in which Acetyl-Coenzyme A and oxaloacetate did not give rise to alpha-ketoglutarate. [5] This may be due to an evolutionary remnant.

Ecology

Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.

Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Application to Biotechnology

Does this organism produce any useful compounds or enzymes? What are they and how are they used?

Current Research

Enter summaries of the most recent research here--at least three required

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by student of Rachel Larsen and Kit Pogliano