Aggregatibacter actinomycetemcomitans

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Aggregatibacter actinomycetemcomitans
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Bacteria
Phylum: Pseudomonadota
Class: Gammaproteobacteria
Order: Pasteurellales
Family: Pasteurellaceae
Genus: Aggregatibacter
Species:
A. actinomycetemcomitans
Binomial name
Aggregatibacter actinomycetemcomitans
(Klinger 1912) Nørskov-Lauritsen and Kilian 2006
Synonyms
  • Actinobacillus actinomycetemcomitans(Klinger 1912) Topley and Wilson 1929 (Approved Lists 1980)
  • "Bacterium actinomycetemcomitans" Klinger 1912
  • Haemophilus actinomycetemcomitans(Klinger 1912) Potts et al. 1985

Aggregatibacter actinomycetemcomitans is a Gram-negative, facultative anaerobe, nonmotile bacterium that is often found in association with localized aggressive periodontitis, a severe infection of the periodontium. It is also suspected to be involved in chronic periodontitis. [1] Less frequently, A. actinomycetemcomitans is associated with nonoral infections such as endocarditis. Its role in aggressive periodontitis was first discovered by Danish-born periodontist Jørgen Slots, a professor of dentistry and microbiology at the University of Southern California School of Dentistry.[ citation needed ]

Contents

'Bacterium actinomycetem comitans' was first described by Klinger (1912) as coccobacillary bacteria isolated with Actinomyces from actinomycotic lesions in humans. It was reclassified as Actinobacillus actinomycetemcomitans by Topley & Wilson (1929) and as Haemophilus actinomycetemcomitans by Potts et al. (1985). The species has attracted attention because of its association with localized aggressive periodontitis. [2]

Nomenclature

Recent studies have shown a phylogenetic similarity of A. actinomycetemcomitans and Haemophilus aphrophilus, H. paraphrophilus, and H. segnis, suggesting the new genus Aggregatibacter for them. [2]

Importance

It is one of the bacteria that might be implicated in destructive periodontal disease. Although it has been found more frequently in localized aggressive periodontitis, [3] prevalence in any population is rather high. It has also been isolated from actinomycotic lesions (mixed infection with certain Actinomyces species, in particular A. israelii). It possesses certain virulence factors that enable it to invade tissues, such as the pore-forming toxin leukotoxin A. It has also been isolated from women with bacterial vaginosis and as an etiologic agent in endocarditis. [4] The pore-forming toxin LtxA of A. actinomycetemcomitans may be a trigger of the autoimmune disease rheumatoid arthritis due to its ability to stimulate protein citrullination, a post-translational protein modification targeted by autoantibodies in this disease. [5] [6]

Virulence factors

A. actinomycetemcomitans serotypes

Small RNA

In bacteria, small RNAs are involved in gene regulation. Jorth et al. identified 9 sRNA by Northern blotting from computer-predicted candidates in strain VT1169 and 202 sRNA by RNA seq in strain 624. [8] [9] A systematic screen by RNA-seq and RT-PCR in HK1651 strain (a clinical isolate from an aggressive periodontitis patient), quantified 70 sRNAs and further identified 17 differentially expressed sRNAs during growth phases. [10] Target prediction indicated possibility of sRNA interaction with several virulence genes. [10] This study confirmed the presence of one of previously identified Fur regulated sRNAs JA04 identified in strain HK1651.[ citation needed ]

See also

Related Research Articles

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<i>Actinomyces</i> Genus of bacteria

Actinomyces is a genus of the Actinomycetia class of bacteria. They all are gram-positive and facultatively anaerobic, growing best under anaerobic conditions. Actinomyces species may form endospores, and while individual bacteria are rod-shaped, Actinomyces colonies form fungus-like branched networks of hyphae. The aspect of these colonies initially led to the incorrect assumption that the organism was a fungus and to the name Actinomyces, "ray fungus".

<span class="mw-page-title-main">Pasteurellaceae</span> Family of bacteria

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<span class="mw-page-title-main">Panton–Valentine leukocidin</span>

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  1. Localized aggressive periodontitis (LAP)
  2. Generalized aggressive periodontitis (GAP)

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Four non-coding small RNAs containing a Fur box-like sequence were identified by bioinformatics analysis in Aggregatibacter actinomycetemcomitansHK1651 called JA01-JA04. The transcription of sRNAs was confirmed by Northern blot. Fur binding was demonstrated to each sRNA promoter, and that transcription of the sRNAs was decreased in presence of iron and increased by iron limitation. JA03 may have the ability to regulate biofilm formation. JA01 is conserved only among A. actinomycetemcomitans. JA02 is present in both A. actinomycetemcomitans and P. multocida. JA 03 and JA04 are most widely conserved and have orthologues across many Pasteurellaceae. HrrF RNA is another Fur-regulated sRNA conserved among the Pasteurcellaceae.

<span class="mw-page-title-main">Jørgen Slots</span> Danish periodontist

Jørgen Slots is a Danish-born periodontist notable for his contributions to the field of periodontology. He is currently professor of periodontology and microbiology at the Herman Ostrow School of Dentistry of USC, and served as chairman of periodontology from 1991 to 2001.

N-glycosyltransferase is an enzyme in prokaryotes which transfers individual hexoses onto asparagine sidechains in substrate proteins, using a nucleotide-bound intermediary, within the cytoplasm. They are distinct from regular N-glycosylating enzymes, which are oligosaccharyltransferases that transfer pre-assembled oligosaccharides. Both enzyme families however target a shared amino acid sequence asparagine—-any amino acid except proline—serine or threonine (N–x–S/T), with some variations.

Aggregatibacter segnis is a species of bacteria. A. segnis can be cultured on chocolate agar.

References

  1. Henderson B, Ward JM, Ready D (October 2010). "Aggregatibacter (Actinobacillus) actinomycetemcomitans: a triple A* periodontopathogen?". Periodontology 2000. 54 (1): 78–105. doi:10.1111/j.1600-0757.2009.00331.x. PMID   20712635.
  2. 1 2 Nørskov-Lauritsen N, Kilian M (September 2006). "Reclassification of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, Haemophilus paraphrophilus and Haemophilus segnis as Aggregatibacter actinomycetemcomitans gen. nov., comb. nov., Aggregatibacter aphrophilus comb. nov. and Aggregatibacter segnis comb. nov., and emended description of Aggregatibacter aphrophilus to include V factor-dependent and V factor-independent isolates". International Journal of Systematic and Evolutionary Microbiology. 56 (Pt 9): 2135–46. doi: 10.1099/ijs.0.64207-0 . PMID   16957111.
  3. Slots J (January 1976). "The predominant cultivable organisms in juvenile periodontitis". Scandinavian Journal of Dental Research. 84 (1): 1–10. doi:10.1111/j.1600-0722.1976.tb00454.x. PMID   1061986.
  4. Africa CW, Nel J, Stemmet M (July 2014). "Anaerobes and bacterial vaginosis in pregnancy: virulence factors contributing to vaginal colonisation". International Journal of Environmental Research and Public Health. 11 (7): 6979–7000. doi: 10.3390/ijerph110706979 . PMC   4113856 . PMID   25014248.
  5. Konig MF, Abusleme L, Reinholdt J, Palmer RJ, Teles RP, Sampson K, Rosen A, Nigrovic PA, Sokolove J, Giles JT, Moutsopoulos NM, Andrade F (December 2016). "Aggregatibacter actinomycetemcomitans-induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis". Science Translational Medicine. 8 (369): 369ra176. doi:10.1126/scitranslmed.aaj1921. PMC   5384717 . PMID   27974664.
  6. Abbasi J (March 2017). "To Prevent Rheumatoid Arthritis, Look Past the Joints to the Gums". JAMA. 317 (12): 1201–1202. doi:10.1001/jama.2017.0764. PMID   28273301.
  7. Haubek D (September 2010). "The highly leukotoxic JP2 clone of Aggregatibacter actinomycetemcomitans: evolutionary aspects, epidemiology and etiological role in aggressive periodontitis". APMIS. Supplementum. 118 (130): 1–53. doi:10.1111/j.1600-0463.2010.02665.x. PMID   21214629. S2CID   20882401.
  8. Jorth P, Whiteley M (December 2010). "Characterization of a novel riboswitch-regulated lysine transporter in Aggregatibacter actinomycetemcomitans". Journal of Bacteriology. 192 (23): 6240–50. doi:10.1128/JB.00935-10. PMC   2981213 . PMID   20889741.
  9. Jorth P, Trivedi U, Rumbaugh K, Whiteley M (November 2013). "Probing bacterial metabolism during infection using high-resolution transcriptomics". Journal of Bacteriology. 195 (22): 4991–8. doi:10.1128/JB.00875-13. PMC   3811578 . PMID   23974023.
  10. 1 2 Oogai Y, Gotoh Y, Ogura Y, Kawada-Matsuo M, Hayashi T, Komatsuzawa H (December 2017). "Small RNA repertoires and their intraspecies variation in Aggregatibacter actinomycetemcomitans". DNA Research. 25 (2): 207–215. doi:10.1093/dnares/dsx050. PMC   5909427 . PMID   29211829.