Information: - Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria, forming the cell wall. The sugar component consists of alternating residues of -(1,4) linked "N"-acetylglucosamine and "N"-acetylmuramic acid. Attached to the "N"-acetylmuramic acid is a peptide chain of three to five amino acids. The peptide chain can be cross-linked to the peptide chain of another strand forming the 3D mesh-like layer. Peptidoglycan serves a structural role in the bacterial cell wall, giving structural strength, as well as counteracting the osmotic pressure of the cytoplasm. A common misconception is that peptidoglycan gives the cell its shape; however, whereas peptidoglycan helps maintain the structural strength of the cell, it is actually the MreB protein that facilitates cell shape. Peptidoglycan is also involved in binary fission during bacterial cell reproduction. - Gammaproteobacteria are a class of several medically, ecologically, and scientifically important groups of bacteria. An exceeding number of important pathogens belong to this class. Like all Proteobacteria, the Gammaproteobacteria are Gram-negative. - A cell wall is a structural layer surrounding some types of cells, situated outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are present in most prokaryotes except mycoplasma bacteria, in algae, plants and fungi but rarely in other eukaryotes including animals. A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters. - Citrobacter is a genus of Gram-negative coliform bacteria in the Enterobacteriaceae family. - Gram-negative bacteria are a group of bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. - The bacterial outer membrane is found in gram-negative bacteria. Its composition is distinct from that of the inner cytoplasmic cell membrane - among other things, the outer leaflet of the outer membrane of many gram-negative bacteria includes a complex lipopolysaccharide whose lipid portion acts as an endotoxin - and in some bacteria such as "E. coli" it is linked to the cell's peptidoglycan by Braun's lipoprotein. - Crystal violet or gentian violet (also known as methyl violet 10B or hexamethyl pararosaniline chloride) is a triarylmethane dye used as a histological stain and in Gram's method of classifying bacteria. Crystal violet has antibacterial, antifungal, and anthelmintic properties and was formerly important as a topical antiseptic. The medical use of the dye has been largely superseded by more modern drugs, although it is still listed by the World Health Organization. - The Enterobacteriaceae are a large family of Gram-negative bacteria that includes, along with many harmless symbionts, many of the more familiar pathogens, such as "Salmonella", "Escherichia coli", "Yersinia pestis", "Klebsiella", and "Shigella". Other disease-causing bacteria in this family include "Proteus", "Enterobacter", "Serratia", and "Citrobacter". This family is the only representative in the order Enterobacteriales of the class Gammaproteobacteria in the phylum Proteobacteria. Phylogenetically, in the Enterobacteriales, several peptidoglycan-less insect endosymbionts form a sister clade to the Enterobacteriaceae, but as they are not validly described, this group is not officially a taxon; examples of these species are "Sodalis", "Buchnera", "Wigglesworthia", "Baumannia cicadellinicola", and "Blochmannia", but not former Rickettsias. Members of the Enterobacteriaceae can be trivially referred to as enterobacteria or "enteric bacteria", as several members live in the intestines of animals. In fact, the etymology of the family is enterobacterium with the suffix to designate a family (aceae)not after the genus "Enterobacter" (which would be "Enterobacteraceae")and the type genus is "Escherichia". - Escherichia is a genus of Gram-negative, nonspore forming, facultatively anaerobic, rod-shaped bacteria from the family Enterobacteriaceae. In those species which are inhabitants of the gastrointestinal tracts of warm-blooded animals, "Escherichia" species provide a portion of the microbially derived vitamin K for their host. A number of the species of "Escherichia" are pathogenic. The genus is named after Theodor Escherich, the discoverer of "Escherichia coli". - Klebsiella is a genus of nonmotile, Gram-negative, oxidase-negative, rod-shaped bacteria with a prominent polysaccharide-based capsule. It is named after the German microbiologist Edwin Klebs (18341913). - The Enterobacteriales are an order of Gram - negative bacteria that includes only one family which is the Enterobacteriaceae . - Escherichia coli (also known as E. coli) is a gram-negative, facultatively anaerobic, rod-shaped, coliform bacterium of the genus "Escherichia" that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Most "E. coli" strains are harmless, but some serotypes can cause serious food poisoning in their hosts, and are occasionally responsible for product recalls due to food contamination. The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K, and preventing colonization of the intestine with pathogenic bacteria. "E. coli" is expelled into the environment within fecal matter. The bacterium grows massively in fresh fecal matter under aerobic conditions for 3 days, but its numbers decline slowly afterwards. - The cell envelope comprises the inner cell membrane and the cell wall of a bacterium, if present, plus a bacterial outer membrane, if one is present (i.e. in gram-negative bacteria). - Enterobacter is a genus of common Gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacteria of the family Enterobacteriaceae. Several strains of these bacteria are pathogenic and cause opportunistic infections in immunocompromised (usually hospitalized) hosts and in those who are on mechanical ventilation. The urinary and respiratory tracts are the most common sites of infection. The genus "Enterobacter" is a member of the coliform group of bacteria. It does not belong to the fecal coliforms (or thermotolerant coliforms) group of bacteria, unlike "Escherichia coli", because it is incapable of growth at 44.5C in the presence of bile salts. Some of them showed quorum sensing properties as reported before - Salmonella is a genus of rod-shaped (bacillus) gram-negative bacteria of the Enterobacteriaceae family. The two species of "Salmonella" are "Salmonella enterica" and "Salmonella bongori". "Salmonella enterica" is the type species and is further divided into six subspecies that include over 2500 serotypes. - Yersinia is a genus of bacteria in the family Enterobacteriaceae. "Yersinia" species are Gram-negative, rod-shaped bacteria, a few micrometers long and fractions of a micrometer in diameter, and are facultative anaerobes. Some members of "Yersinia" are pathogenic in humans; in particular, "Y. pestis" is the causative agent of the plague. Rodents are the natural reservoirs of "Yersinia"; less frequently, other mammals serve as the host. Infection may occur either through blood (in the case of "Y. pestis") or in an alimentary fashion, occasionally via consumption of food products (especially vegetables, milk-derived products, and meat) contaminated with infected urine or feces. - In cell biology, the cytoplasm is the material within a living cell, excluding the cell nucleus. It comprises cytosol (the gel-like substance enclosed within the cell membrane) and the organelles the cell's internal sub-structures. All of the contents of the cells of prokaryote organisms (such as bacteria, which lack a cell nucleus) are contained within the cytoplasm. Within the cells of eukaryote organisms the contents of the cell nucleus are separated from the cytoplasm, and are then called the nucleoplasm. The cytoplasm is about 80% water and usually colorless. - The "Proteobacteria" are a major phylum of Gram-negative bacteria. The name of the phylum has never been validly published as no type genus has been proposed, thus it must be styled in quotation marks as the name has no standing in nomenclature. They include a wide variety of pathogens, such as "Escherichia", "Salmonella", "Vibrio", "Helicobacter", "Yersinia", and many other notable genera. Others are free-living (nonparasitic), and include many of the bacteria responsible for nitrogen fixation. - Shigella is a genus of Gram-negative, facultative anaerobic, nonspore-forming, nonmotile, rod-shaped bacteria closely related to "Salmonella". The genus is named after Kiyoshi Shiga, who first discovered it in 1897. - Serratia is a genus of Gram-negative, facultatively anaerobic, endosporeforming, rod-shaped bacteria of the Enterobacteriaceae family. The most common and pathogenic of the species in the genus, "S. marcescens", is normally the only pathogen and usually causes nosocomial infections. However, rare strains of "S. plymuthica", "S. liquefaciens", "S. rubidaea", and "S. odoriferae" have caused diseases through infection. "S. marcescens" is typically found in showers, toilet bowls, and around wetted tiles. Members of this genus produce characteristic red pigment, prodigiosin, and can be distinguished from other members of the Enterobacteriaceae family by their unique production of three enzymes: DNase, lipase, and gelatinase. A pan-genome analysis of the genus "Serratia" revealed that it does not depict exceptional genetic conservation or diversity as compared to other bacterial genera. - Bacteria (common noun bacteria, singular bacterium) constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. - Yersinia pestis (formerly "Pasteurella pestis") is a Gram-negative, rod-shaped coccobacillus, a facultative anaerobic organism that can infect humans via the oriental rat flea. It causes the deadly disease called Bubonic Plague (or "the Plague" colloquially). Human "Y. pestis" infection takes three main forms: pneumonic, septicemic, and bubonic plagues. All three forms were responsible for a number of high-mortality epidemics throughout human history, including: the sixth century's Plague of Justinian; the Black Death, which accounted for the death of at least one-third of the European population between 1347 and 1353; and the 19th century's Third Pandemic. These plagues probably originated in China and were transmitted west via trade routes. What object entity has the relation of 'parent taxon' with the subject 'enterobacteriales'? Choices: - bacillus - bacteria - citrobacter - enterobacter - enterobacteriaceae - enterobacteriales - escherichia - fungi - gammaproteobacteria - human - klebsiella - mycoplasma - pasteurella - prokaryotes - proteobacteria - rat - salmonella - serratia - shigella - yersinia
A:
gammaproteobacteria