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.
A coccobacillus, or bacilluscocco, is a type of bacterium with a shape intermediate between cocci and bacilli. Coccobacilli, then, are very short rods which may be mistaken for cocci.
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. 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.
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. It is a member of the family Pasteurellaceae. The bacteria are facultatively anaerobic or aerobic, capable of fermenting carbohydrates, and of reducing nitrates. The genomic DNA contains between 40 and 47 mol % guanine plus cytosine.
Bacterial cellular morphologies are morphologies that are characteristic of various types bacteria and often a key factor in identifying bacteria species. Their direct examination under the light microscope enables the classification of these bacteria and archaea.
Aggregatibacter aphrophilus is a species of bacteria. It is one of the HACEK organisms.
Thermoanaerobacter is a genus in the phylum Bacillota (Bacteria). Members of this genus are thermophilic and anaerobic, several of them were previously described as Clostridium species and members of the now obsolete genera Acetogenium and Thermobacteroides
Acidiphilium is a genus in the phylum Pseudomonadota (Bacteria). As the name suggests, this comprises a nutritionally diverse genus of bacteria adapted to life in extremely acidic conditions, and often exhibiting FeIII reduction.
Actinoallomurus is a genus in the phylum Actinomycetota (Bacteria).
Actinoalloteichus is a genus in the phylum Actinomycetota (Bacteria).
Actinokineospora is a genus in the phylum Actinomycetota (Bacteria).
Actinospica is a genus in the phylum Actinomycetota (Bacteria).
Actinotalea is a genus in the phylum Actinomycetota (bacteria).
Algoriphagus is a genus in the phylum Bacteroidota (Bacteria).
Alkalibacillus is a genus in the phylum Bacillota (Bacteria).
Crossiella is a genus in the phylum Actinomycetota (Bacteria).
Haemophilus pittmaniae is a Gram-negative species of bacterium of the family Pasteurellaceae. Strains of this species were originally isolated from humans. The species may be associated with respiratory infections in individuals with lung disease.
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.
