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Actinobacillus suis.jpg
Actinobacillus suis
Scientific classification

Brumpt 1910

A. actinomycetemcomitans
A. arthritidis
A. capsulatus
A. delphinicola
A. equuli
A. hominis
A. indolicus
A. lignieresii
A. minor
A. muris
A. pleuropneumoniae
A. porcinus
A. rossii
A. scotiae
A. seminis
A. succinogenes
A. suis
A. ureae

Actinobacillus is a genus of Gram-negative, nonmotile and non-spore-forming, oval to rod-shaped bacteria occurring as parasites or pathogens in mammals, birds, and reptiles. [1] It is a member of the Pasteurellaceae family. [2] The bacteria are facultatively aerobic or anaerobic, capable of fermenting carbohydrates (without production of gas), and of reducing nitrates. The genomic DNA contains between 40 and 47 mol % guanine plus cytosine.

Pasteurellaceae family of bacteria

The Pasteurellaceae comprise a large family of Gram-negative bacteria. Most members live as commensals on mucosal surfaces of birds and mammals, especially in the upper respiratory tract. Pasteurellaceae are typically rod-shaped, and are a notable group of facultative anaerobes. Their biochemical characteristics can be distinguished from the related Enterobacteriaceae by the presence of oxidase, and from most other similar bacteria by the absence of flagella.

Actinobacillus ( Pasteurella ) ureae and A. hominis occur in the respiratory tracts of healthy humans and may be involved in the pathogenesis of sinusitis, bronchopneumonia, and meningitis. A. actinomycetemcomitans occurs in the human oral microflora, [3] and together with anaerobic or capnophilic organisms (HACEK group organisms) may cause endocarditis. Actinobacilli are susceptible to most antibiotics of the beta-lactam family, aminoglycosides, tetracyclines, chloramphenicol, and many other antibacterial chemotherapeutics.

Sinusitis human disease

Sinusitis, also known as a sinus infection or rhinosinusitis, is inflammation of the mucous membrane that lines the sinuses resulting in symptoms. Common symptoms include thick nasal mucus, a plugged nose, and facial pain. Other signs and symptoms may include fever, headaches, poor sense of smell, sore throat, and cough. The cough is often worse at night. Serious complications are rare. It is defined as acute sinusitis if it lasts less than 4 weeks, and as chronic sinusitis if it lasts for more than 12 weeks.

Oral microbiology is the study of the microorganisms (microbiota) of the oral cavity and their interactions between oral microorganisms or with the host. The environment present in the human mouth allows the growth of characteristic microorganisms found there. It provides a source of water and nutrients, as well as a moderate temperature. Resident microbes of the mouth adhere to the teeth and gums to resist mechanical flushing from the mouth to stomach where acid-sensitive microbes are destroyed by hydrochloric acid.

Aminoglycoside molecule or a portion of a molecule composed of amino-modified sugars

Aminoglycoside is a medicinal and bacteriologic category of traditional Gram-negative antibacterial medications that inhibit protein synthesis and contain as a portion of the molecule an amino-modified glycoside (sugar). The term can also refer more generally to any organic molecule that contains amino sugar substructures. Aminoglycoside antibiotics display bactericidal activity against Gram-negative aerobes and some anaerobic bacilli where resistance has not yet arisen but generally not against Gram-positive and anaerobic Gram-negative bacteria.

An analysis of A. actinomycetemcomitans indicated it was monophyletic with Haemophilus aphrophilus and H. segnis, and it was proposed that they be reclassified as a new genus, Aggregatibacter (from the Latin, "aggregare", meaning "to come together"). [4] [5]

Monophyly Property of a group of including all taxa descendant from a common ancestral species

In cladistics, a monophyletic group, or clade, is a group of organisms that consists of all the descendants of a common ancestor. Monophyletic groups are typically characterised by shared derived characteristics (synapomorphies), which distinguish organisms in the clade from other organisms. The arrangement of the members of a monophyletic group is called a monophyly.

Aggregatibacter is a genus in the phylum Proteobacteria (Bacteria), which contains three species, namely:

Related Research Articles

<i>Helicobacter</i> genus of bacteria

Helicobacter is a genus of Gram-negative bacteria possessing a characteristic helical shape. They were initially considered to be members of the genus Campylobacter, but in 1989, Goodwin et al. published sufficient reasons to justify the new genus name Helicobacter. The genus Helicobacter contains about 35 species.

Pasteurellosis is an infection with a species of the bacterial genus Pasteurella, which is found in humans and other animals.

The HACEK organisms are a group of fastidious gram-negative bacteria that are an unusual cause of infective endocarditis, which is an inflammation of the heart due to bacterial infection. HACEK is an abbreviation of the initials of the genera of this group of bacteria: Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella. The HACEK organisms are a normal part of the human microbiota, living in the oral-pharyngeal region.

Pseudomonadales order of bacteria

The Pseudomonadales are an order of Proteobacteria. A few members are opportunistic pathogens, such as species of Pseudomonas, Moraxella, and Acinetobacter, which may cause pneumonia.

<i>Haemophilus</i> genus of bacteria

Haemophilus is a genus of Gram-negative, pleomorphic, coccobacilli bacteria belonging to the family Pasteurellaceae. While Haemophilus bacteria are typically small coccobacilli, they are categorized as pleomorphic bacteria because of the wide range of shapes they occasionally assume. These organisms inhabit the mucous membranes of the upper respiratory tract, mouth, vagina, and intestinal tract. The genus includes commensal organisms along with some significant pathogenic species such as H. influenzae—a cause of sepsis and bacterial meningitis in young children—and H. ducreyi, the causative agent of chancroid. All members are either aerobic or facultatively anaerobic. This genus has been found to be part of the salivary microbiome.

<i>Staphylococcus epidermidis</i> species of bacterium

Staphylococcus epidermidis is a Gram-positive bacterium, and one of over 40 species belonging to the genus Staphylococcus. It is part of the normal human flora, typically the skin flora, and less commonly the mucosal flora. It is a facultative anaerobic bacteria. Although S. epidermidis is not usually pathogenic, patients with compromised immune systems are at risk of developing infection. These infections are generally hospital-acquired. S. epidermidis is a particular concern for people with catheters or other surgical implants because it is known to form biofilms that grow on these devices. Being part of the normal skin flora, S. epidermidis is a frequent contaminant of specimens sent to the diagnostic laboratory.

Food microbiology

Food microbiology is the study of the microorganisms that inhibit, create, or contaminate food, including the study of microorganisms causing food spoilage, pathogens that may cause disease especially if food is improperly cooked or stored, those used to produce fermented foods such as cheese, yogurt, bread, beer, and wine, and those with other useful roles such as producing probiotics.

Biotransformation is the chemical modification (or modifications) made by an organism on a chemical compound. If this modification ends in mineral compounds like CO2, NH4+, or H2O, the biotransformation is called mineralisation.

Aggregatibacter actinomycetemcomitans is a Gram-negative, facultative anaerobe, non-motile 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. Less frequently, A. actinomycetemcomitans is associated with non-oral 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.

Microbial biodegradation is the use of bioremediation and biotransformation methods to harness the naturally occurring ability of microbial xenobiotic metabolism to degrade, transform or accumulate environmental pollutants, including hydrocarbons, polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), heterocyclic compounds, pharmaceutical substances, radionuclides and metals.

Microbiology study of microscopic organisms

Microbiology is the study of microorganisms, those being unicellular, multicellular, or acellular. Microbiology encompasses numerous sub-disciplines including virology, parasitology, mycology and bacteriology.

Haemophilus segnis is a bacterium.

Haemophilus pittmaniae is a Gram-negative species of bacterium belonging to the Pasteurellaceae family. Strains of this species were originally isolated from humans. The species may be associated with respiratory infections in individuals with lung disease.

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.

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.


  1. Chung; et al. (2008). "Actinobacillus pleuropneumoniae". Pasteurellaceae: Biology, Genomics and Molecular Aspects. Caister Academic Press. ISBN   978-1-904455-34-9.
  2. Kuhnert P; Christensen H (editors). (2008). Pasteurellaceae: Biology, Genomics and Molecular Aspects. Caister Academic Press. ISBN   978-1-904455-34-9.
  3. Rogers A H (editor). (2008). Molecular Oral Microbiology. Caister Academic Press. ISBN   978-1-904455-24-0.
  4. 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". Int. J. Syst. Evol. Microbiol. 56 (Pt 9): 2135–46. doi:10.1099/ijs.0.64207-0. PMID   16957111.
  5. Nørskov-Lauritsen, N (Apr 2014). "Classification, identification, and clinical significance of haemophilus and aggregatibacter species with host specificity for humans". Clinical Microbiology Reviews. 27 (2): 214–40. doi:10.1128/CMR.00103-13. PMC   3993099 . PMID   24696434.