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127-416: See text. Pseudomonas is a genus of Gram-negative bacteria belonging to the family Pseudomonadaceae in the class Gammaproteobacteria . The 313 members of the genus demonstrate a great deal of metabolic diversity and consequently are able to colonize a wide range of niches. Their ease of culture in vitro and availability of an increasing number of Pseudomonas strain genome sequences has made

254-499: A phenazine -type antibiotic active agent against certain fungal plant pathogens, and the closely related species P. aurantiaca , which produces di-2,4-diacetylfluoroglucylmethane , a compound antibiotically active against Gram-positive organisms. Some members of the genus are able to metabolise chemical pollutants in the environment, and as a result, can be used for bioremediation . Notable species demonstrated as suitable for use as bioremediation agents include: Pseudomonas

381-623: A terminal electron acceptor . When oxygen, nitrate, and nitrite are absent, it is able to ferment arginine and pyruvate by substrate-level phosphorylation . Additionally, phenazines produced by P. aeruginosa can act as electron shuttles to facilitate survival of cells at depth in biofilms. Adaptation to microaerobic or anaerobic environments is essential for certain lifestyles of P. aeruginosa , for example, during lung infection in cystic fibrosis and primary ciliary dyskinesia , where thick layers of lung mucus and bacterially-produced alginate surrounding mucoid bacterial cells can limit

508-491: A "fruity" odor. Most Pseudomonas spp. are naturally resistant to penicillin and the majority of related beta-lactam antibiotics , but a number are sensitive to piperacillin , imipenem , ticarcillin , or ciprofloxacin . Aminoglycosides such as tobramycin , gentamicin , and amikacin are other choices for therapy. This ability to thrive in harsh conditions is a result of their hardy cell walls that contain proteins known as porins . Their resistance to most antibiotics

635-502: A characteristic "grape-like" or "fresh-tortilla" odor on bacteriological media. In mixed cultures, it can be isolated as clear colonies on MacConkey agar (as it does not ferment lactose ) which will test positive for oxidase . Confirmatory tests include production of the blue-green pigment pyocyanin on cetrimide agar and growth at 42 °C. A TSI slant is often used to distinguish nonfermenting Pseudomonas species from enteric pathogens in faecal specimens. When P. aeruginosa

762-413: A decrease in fitness, while cheaters have an increase in fitness. The magnitude of change in fitness increases with increasing iron limitation. With an increase in fitness, the cheaters can outcompete the cooperators; this leads to an overall decrease in fitness of the group, due to lack of sufficient siderophore production. These observations suggest that having a mix of cooperators and cheaters can reduce

889-604: A delayed manner. So, las is a direct and indirect regulator of QS-controlled genes. Another form of gene regulation that allows the bacteria to rapidly adapt to surrounding changes is through environmental signaling. Recent studies have discovered anaerobiosis can significantly impact the major regulatory circuit of QS. This important link between QS and anaerobiosis has a significant impact on production of virulence factors of this organism. Garlic experimentally blocks quorum sensing in P. aeruginosa . As in most Gram negative bacteria, P. aeruginosa biofilm formation

1016-455: A genetic basis exists behind bacterial antibiotic resistance, rather than the biofilm simply acting as a diffusion barrier to the antibiotic. Depending on the nature of infection, an appropriate specimen is collected and sent to a bacteriology laboratory for identification. As with most bacteriological specimens, a Gram stain is performed, which may show Gram-negative rods and/or white blood cells . P. aeruginosa produces colonies with

1143-407: A genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

1270-508: A higher risk. A comparative genomic analysis of 494 complete Pseudomonas genomes, including 189 complete P. aeruginosa genomes, identified several proteins that are shared by the vast majority of P. aeruginosa strains, but are not observed in other analyzed Pseudomonas genomes. These aeruginosa-specific core proteins, such as CntL, CntM, PlcB, Acp1, MucE, SrfA, Tse1, Tsi2, Tse3, and EsrC are known to play an important role in this species' pathogenicity. P. aeruginosa uses

1397-441: A large range of antibiotics and may demonstrate additional resistance after unsuccessful treatment. It should usually be possible to guide treatment according to laboratory sensitivities, rather than choosing an antibiotic empirically . If antibiotics are started empirically, then every effort should be made to obtain cultures (before administering the first dose of antibiotic), and the choice of antibiotic used should be reviewed when

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1524-651: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

1651-628: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

1778-573: A neural network which can then differentiate between milk spoilage microorganisms such as P. fluorescens and P. aureofaciens . Pseudomonas comprises the following species, organized into genomic affinity groups: P. asplenii Subgroup P. chlororaphis Subgroup P. corrugata Subgroup P. fluorescens Subgroup P. fragi Subgroup P. gessardii Subgroup P. jessenii Subgroup P. koreensis Subgroup P. mandelii Subgroup P. protegens Subgroup incertae sedis Recently, 16S rRNA sequence analysis redefined

1905-416: A positive result to the oxidase test , the absence of gas formation from glucose, glucose is oxidised in oxidation/fermentation test using Hugh and Leifson O/F test, beta hemolytic (on blood agar ), indole negative, methyl red negative, Voges–Proskauer test negative, and citrate positive. Pseudomonas may be the most common nucleator of ice crystals in clouds, thereby being of utmost importance to

2032-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

2159-551: A seems to be a pathogen that primarily affects humans, another strain known as Pseudomonas plecoglossicida poses risks to fish. This strain can cause gastric swelling and haemorrhaging in fish populations. Various strains of Pseudomonas are recognized as pathogens in the plant kingdom. Notably, the Pseudomonas syringae family is linked to diseases affecting a wide range of agricultural plants, with different strains showing adaptations to specific host species. In particular,

2286-404: A serious problem for medical care in industrialized societies, especially for immunocompromised patients and the elderly. They often cannot be treated effectively with traditional antibiotic therapy. Biofilms serve to protect these bacteria from adverse environmental factors, including host immune system components in addition to antibiotics. P. aeruginosa can cause nosocomial infections and

2413-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

2540-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

2667-584: Is citrate , catalase , and oxidase positive . It is found in soil, water, skin flora , and most human-made environments throughout the world. It thrives not only in normal atmospheres, but also in low-oxygen atmospheres, thus has colonized many natural and artificial environments. It uses a wide range of organic material for food; in animals, its versatility enables the organism to infect damaged tissues or those with reduced immunity. The symptoms of such infections are generalized inflammation and sepsis . If such colonizations occur in critical body organs, such as

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2794-447: Is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes . P. aeruginosa is able to selectively inhibit various antibiotics from penetrating its outer membrane - and has high resistance to several antibiotics. According to

2921-399: Is a Latin word meaning verdigris ("copper rust"), referring to the blue-green color of laboratory cultures of the species. This blue-green pigment is a combination of two secondary metabolites of P. aeruginosa , pyocyanin (blue) and pyoverdine (green), which impart the blue-green characteristic color of cultures. Another assertion from 1956 is that aeruginosa may be derived from

3048-401: Is a fluorescent-yellow color. The genome of Pseudomonas aeruginosa consists of a relatively large circular chromosome (5.5–6.8   Mb) that carries between 5,500 and 6,000 open reading frames , and sometimes plasmids of various sizes depending on the strain. Comparison of 389 genomes from different P. aeruginosa strains showed that just 17.5% is shared. This part of the genome

3175-450: Is a genus of bacteria known to be associated with several diseases affecting humans, plants, and animals. One of the most concerning strains of Pseudomonas is Pseudomonas aeruginosa , which is responsible for a considerable number of hospital-acquired infections. Numerous hospitals and medical facilities face persistent challenges in dealing with Pseudomonas infections. The symptoms of these infections are caused by proteins secreted by

3302-526: Is a prolific plant pathogen . It exists as over 50 different pathovars , many of which demonstrate a high degree of host-plant specificity. Numerous other Pseudomonas species can act as plant pathogens, notably all of the other members of the P. syringae subgroup, but P. syringae is the most widespread and best-studied. P. tolaasii can be a major agricultural problem, as it can cause bacterial blotch of cultivated mushrooms . Similarly, P. agarici can cause drippy gill in cultivated mushrooms. Since

3429-411: Is also a common cause of postoperative infection in radial keratotomy surgery patients. The organism is also associated with the skin lesion ecthyma gangrenosum . P. aeruginosa is frequently associated with osteomyelitis involving puncture wounds of the foot, believed to result from direct inoculation with P. aeruginosa via the foam padding found in tennis shoes, with diabetic patients at

3556-476: Is attributed to efflux pumps , which pump out some antibiotics before they are able to act. Pseudomonas aeruginosa is increasingly recognized as an emerging opportunistic pathogen of clinical relevance. One of its most worrying characteristics is its low antibiotic susceptibility. This low susceptibility is attributable to a concerted action of multidrug efflux pumps with chromosomally encoded antibiotic resistance genes (e.g., mexAB-oprM , mexXY , etc.) and

3683-516: Is being investigated. The risk of contracting P. aeruginosa can be reduced by avoiding pools, hot tubs, and other bodies of standing water; regularly disinfecting and/or replacing equipment that regularly encounters moisture (such as contact lens equipment and solutions); and washing one's hands often (which is protective against many other pathogens as well). However, even the best hygiene practices cannot totally protect an individual against P. aeruginosa, given how common P. aeruginosa

3810-457: Is capable of extensive colonization, and can aggregate into enduring biofilms . The word Pseudomonas means "false unit", from the Greek pseudēs ( Greek : ψευδής, false) and ( Latin : monas , from Greek : μονάς, a single unit). The stem word mon was used early in the history of microbiology to refer to microorganisms and germs , e.g., kingdom Monera . The species name aeruginosa

3937-462: Is composed of nucleic acids, amino acids, carbohydrates, and various ions. It mechanically and chemically protects P. aeruginosa from aggression by the immune system and some toxic compounds. P. aeruginosa biofilm's matrix is composed of up to three types of sugar polymers (or "exopolysacharides") named PSL, PEL, and alginate. Which exopolysacharides are produced varies by strain. Upon certain cues or stresses, P. aeruginosa revert

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4064-420: Is considered a model organism for the study of antibiotic-resistant bacteria. Researchers consider it important to learn more about the molecular mechanisms that cause the switch from planktonic growth to a biofilm phenotype and about the role of QS in treatment-resistant bacteria such as P. aeruginosa . This should contribute to better clinical management of chronically infected patients, and should lead to

4191-731: Is considered as the most important . An important factor found to be associated with antibiotic resistance is the decrease in the virulence capabilities of the resistant strain. Such findings have been reported in the case of rifampicin-resistant and colistin-resistant strains, in which decrease in infective ability, quorum sensing, and motility have been documented. Mutations in DNA gyrase are commonly associated with antibiotic resistance in P. aeruginosa . These mutations, when combined with others, confer high resistance without hindering survival. Additionally, genes involved in cyclic-di-GMP signaling may contribute to resistance. When P. aeruginosa

4318-612: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

4445-511: Is from Pseudomonas . Cystic fibrosis patients are also predisposed to P. aeruginosa infection of the lungs due to a functional loss in chloride ion movement across cell membranes as a result of a mutation . P. aeruginosa may also be a common cause of "hot-tub rash" ( dermatitis ), caused by lack of proper, periodic attention to water quality. Since these bacteria thrive in moist environments, such as hot tubs and swimming pools, they can cause skin rash or swimmer's ear. Pseudomonas

4572-523: Is grown under in vitro conditions designed to mimic a cystic fibrosis patient's lungs, these genes mutate repeatedly. Two small RNAs , Sr0161 and ErsA , were shown to interact with mRNA encoding the major porin OprD responsible for the uptake of carbapenem antibiotics into the periplasm . The sRNAs bind to the 5'UTR of oprD , causing increase in bacterial resistance to meropenem . Another sRNA, Sr006 , may positively regulate (post-transcriptionally)

4699-517: Is in the environment. Phage therapy against P. aeruginosa has been investigated as a possible effective treatment, which can be combined with antibiotics, has no contraindications and minimal adverse effects. Phages are produced as sterile liquid, suitable for intake, applications etc. Phage therapy against ear infections caused by P. aeruginosa was reported in the journal Clinical Otolaryngology in August 2009. As of 2024, research on

4826-452: Is isolated from a normally sterile site (blood, bone, deep collections), it is generally considered dangerous, and almost always requires treatment. However, P. aeruginosa is frequently isolated from nonsterile sites (mouth swabs, sputum , etc.), and, under these circumstances, it may represent colonization and not infection. The isolation of P. aeruginosa from nonsterile specimens should, therefore, be interpreted cautiously, and

4953-447: Is known to control expression of a number of virulence factors in a hierarchical manner, including the pigment pyocyanin. However, although the las system initiates the regulation of gene expression, its absence does not lead to loss of virulence factors. Recently, it has been demonstrated that the rhl system partially controls las-specific factors, such as proteolytic enzymes responsible for elastolytic and staphylolytic activities, but in

5080-427: Is not commonly found in the environment. Iron is usually found in a largely insoluble ferric form. Furthermore, excessively high levels of iron can be toxic to P. aeruginosa . To overcome this and regulate proper intake of iron, P. aeruginosa uses siderophores , which are secreted molecules that bind and transport iron. These iron-siderophore complexes, however, are not specific. The bacterium that produced

5207-491: Is not properly cleaned or on the hands of healthcare workers. Pseudomonas can, in rare circumstances, cause community-acquired pneumonias , as well as ventilator -associated pneumonias, being one of the most common agents isolated in several studies. Pyocyanin is a virulence factor of the bacteria and has been known to cause death in C. elegans by oxidative stress . However, salicylic acid can inhibit pyocyanin production. One in ten hospital-acquired infections

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5334-435: Is regulated by one single molecule: cyclic di-GMP . At low cyclic di-GMP concentration, P. aeruginosa has a free-swimming mode of life. But when cyclic di-GMP levels increase, P. aeruginosa start to establish sessile communities on surfaces. The intracellular concentration of cyclic di-GMP increases within seconds when P. aeruginosa touches a surface ( e.g. : a rock, plastic, host tissues...). This activates

5461-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

5588-453: Is superficial and limited (for example, ear infections or nail infections), topical gentamicin or colistin may be used . For pseudomonal wound infections, acetic acid with concentrations from 0.5% to 5% can be an effective bacteriostatic agent in eliminating the bacteria from the wound. Usually a sterile gauze soaked with acetic acid is placed on the wound after irrigation with normal saline. Dressing would be done once per day. Pseudomonas

5715-527: Is the P. aeruginosa core genome. A comparative genomic study (in 2020) analyzed 494 complete genomes from the Pseudomonas genus, of which 189 were P. aeruginosa strains. The study observed that their protein count and GC content ranged between 5500 and 7352 (average: 6192) and between 65.6 and 66.9% (average: 66.1%), respectively. This comparative analysis further identified 1811 aeruginosa-core proteins, which accounts for more than 30% of

5842-439: Is the type species of the genus Pseudomonas . Identification of P. aeruginosa can be complicated by the fact individual isolates often lack motility. The colony morphology itself also displays several varieties. The main two types are large, smooth, with a flat edge and elevated center and small, rough, and convex. A third type, mucoid, can also be found. The large colony can typically be found in clinal settings while

5969-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

6096-528: Is the low permeability of the bacterial cellular envelopes. In addition to this intrinsic resistance, P. aeruginosa easily develops acquired resistance either by mutation in chromosomally encoded genes or by the horizontal gene transfer of antibiotic resistance determinants. Development of multidrug resistance by P. aeruginosa isolates requires several different genetic events, including acquisition of different mutations and/or horizontal transfer of antibiotic resistance genes. Hypermutation favours

6223-737: Is usually eliminated in 90% of the cases after 10 to 14 days of treatment. One of the most worrisome characteristics of P. aeruginosa is its low antibiotic susceptibility, which is attributable to a concerted action of multidrug efflux pumps with chromosomally encoded antibiotic resistance genes, i.e., the genes that encode proteins that serve as enzymes to break down antibiotics. Examples of such genes are: Specific genes and enzymes involved in antibiotic resistance can vary between different strains. P. aeruginosa TG523 harbored genes predicted to have antibacterial activity and those which are implicated in virulence. Another feature that contributes to antibiotic resistance of P. aeruginosa

6350-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

6477-824: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

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6604-709: The World Health Organization P. aeruginosa poses one of the greatest threats to humans in terms of antibiotic resistance. The organism is considered opportunistic insofar as serious infection often occurs during existing diseases or conditions   – most notably cystic fibrosis and traumatic burns. It generally affects the immunocompromised but can also infect the immunocompetent as in hot tub folliculitis . Treatment of P. aeruginosa infections can be difficult due to its natural resistance to antibiotics. When more advanced antibiotic drug regimens are needed adverse effects may result. It

6731-594: The lungs , the urinary tract , and kidneys , the results can be fatal. Because it thrives on moist surfaces, this bacterium is also found on and in medical equipment , including catheters , causing cross- infections in hospitals and clinics . It is also able to decompose hydrocarbons and has been used to break down tarballs and oil from oil spills . P. aeruginosa is not extremely virulent in comparison with other major species of pathogenic bacteria such as Gram-positive Staphylococcus aureus and Streptococcus pyogenes   – though P. aeruginosa

6858-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

6985-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

7112-419: The pseudomonads were observed early in the history of microbiology . The generic name Pseudomonas created for these organisms was defined in rather vague terms by Walter Migula in 1894 and 1900 as a genus of Gram-negative, rod-shaped, and polar- flagellated bacteria with some sporulating species. The latter statement was later proved incorrect and was due to refractive granules of reserve materials. Despite

7239-435: The virulence factor exotoxin A to inactivate eukaryotic elongation factor 2 via ADP-ribosylation in the host cell, much as the diphtheria toxin does. Without elongation factor   2, eukaryotic cells cannot synthesize proteins and necrotise. The release of intracellular contents induces an immunologic response in immunocompetent patients. In addition P. aeruginosa uses an exoenzyme, ExoU, which degrades

7366-850: The Average Nucleotide Identity levels. In addition, the phylogenomic analysis identified several strains that were mis-annotated to the wrong species or evolutionary group. This mis-annotation problem has been reported by other analyses as well. In 2000, the complete genome sequence of a Pseudomonas species was determined; more recently, the sequence of other strains has been determined, including P. aeruginosa strains PAO1 (2000), P. putida KT2440 (2002), P. protegens Pf-5 (2005), P. syringae pathovar tomato DC3000 (2003), P. syringae pathovar syringae B728a (2005), P. syringae pathovar phaseolica 1448A (2005), P. fluorescens Pf0-1, and P. entomophila L48. By 2016, more than 400 strains of Pseudomonas had been sequenced. Sequencing

7493-409: The Greek prefix ae- meaning "old or aged", and the suffix ruginosa means wrinkled or bumpy. The names pyocyanin and pyoverdine are from the Greek, with pyo- , meaning "pus", cyanin , meaning "blue", and verdine , meaning "green". Hence, the term "pyocyanic bacteria" refers specifically to the "blue pus" characteristic of a P. aeruginosa infection. Pyoverdine in the absence of pyocyanin

7620-681: The Liverpool epidemic strain (LES) which is found mainly in the UK, DK2 in Denmark, and AUST-02 in Australia (also previously known as AES-2 and P2). There is also a clone that is frequently found infecting the reproductive tracts of horses. P. aeruginosa is a facultative anaerobe , as it is well adapted to proliferate in conditions of partial or total oxygen depletion. This organism can achieve anaerobic growth with nitrate or nitrite as

7747-486: The activation of numerous QS-controlled genes, the pqs system is involved in quinolone signaling, and the iqs system plays an important role in intercellular communication. QS in P. aeruginosa is organized in a hierarchical manner. At the top of the signaling hierarchy is the las system, since the las regulator initiates the QS regulatory system by activating the transcription of a number of other regulators, such as rhl. So,

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7874-602: The advice of a microbiologist or infectious diseases physician/pharmacist should be sought prior to starting treatment. Often, no treatment is needed. Morphological, physiological, and biochemical characteristics of Pseudomonas aeruginosa are shown in the Table below. Note: + = Positive, - =Negative P. aeruginosa is a Gram-negative, aerobic (and at times facultatively anaerobic ), rod-shaped bacterium with unipolar motility . It has been identified as an opportunistic pathogen of both humans and plants. P. aeruginosa

8001-421: The bacteria and may include pneumonia , blood poisoning , and urinary tract infections . Pseudomonas aeruginosa is highly contagious and has displayed resistance to antibiotic treatments, making it difficult to manage effectively. Some strains of Pseudomonas are known to target white blood cells in various mammal species , posing risks to humans, cattle, sheep, and dogs alike. While Pseudomonas aeruginos

8128-655: The bacteria. Phenazines are redox-active pigments produced by P. aeruginosa . These pigments are involved in quorum sensing , virulence , and iron acquisition. P. aeruginosa produces several pigments all produced by a biosynthetic pathway: phenazine-1-carboxamide (PCA), 1-hydroxyphenazine, 5-methylphenazine-1-carboxylic acid betaine, pyocyanin and aeruginosin A. Two nearly identical operons are involved in phenazine biosynthesis: phzA1B1C1D1E1F1G1 and phzA2B2C2D2E2F2G2 . The enzymes encoded by these operons convert chorismic acid to PCA. The products of three key genes, phzH , phzM , and phzS then convert PCA to

8255-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

8382-536: The biofilm program and detach. Recent studies have shown that the dispersed cells from P. aeruginosa biofilms have lower cyclic di-GMP levels and different physiologies from those of planktonic and biofilm cells, with unique population dynamics and motility. Such dispersed cells are found to be highly virulent against macrophages and C. elegans , but highly sensitive towards iron stress, as compared with planktonic cells. Biofilms of P. aeruginosa can cause chronic opportunistic infections , which are

8509-497: The culture results are available. Due to widespread resistance to many common first-line antibiotics, carbapenems , polymyxins , and more recently tigecycline were considered to be the drugs of choice; however, resistance to these drugs has also been reported. Despite this, they are still being used in areas where resistance has not yet been reported. Use of β-lactamase inhibitors such as sulbactam has been advised in combination with antibiotics to enhance antimicrobial action even in

8636-425: The development of new drugs. Scientists have been examining the possible genetic basis for P. aeruginosa resistance to antibiotics such as tobramycin . One locus identified as being an important genetic determinant of the resistance in this species is ndvB , which encodes periplasmic glucans that may interact with antibiotics and cause them to become sequestered into the periplasm. These results suggest

8763-411: The diffusion of oxygen. P. aeruginosa growth within the human body can be asymptomatic until the bacteria form a biofilm, which overwhelms the immune system. These biofilms are found in the lungs of people with cystic fibrosis and primary ciliary dyskinesia, and can prove fatal. P. aeruginosa relies on iron as a nutrient source to grow. However, iron is not easily accessible because it

8890-409: The discovery of new antibiotics and drugs against P. aeruginosa is very much needed. Antibiotics that may have activity against P. aeruginosa include: As fluoroquinolones are one of the few antibiotic classes widely effective against P. aeruginosa , in some hospitals, their use is severely restricted to avoid the development of resistant strains. On the rare occasions where infection

9017-471: The expression of PagL, an enzyme responsible for deacylation of lipid A. This reduces the pro-inflammatory property of lipid A. Furthermore, similar to a process found in Salmonella , Sr006 regulation of PagL expression may aid in polymyxin B resistance. Probiotic prophylaxis may prevent colonization and delay onset of Pseudomonas infection in an ICU setting. Immunoprophylaxis against Pseudomonas

9144-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

9271-673: The formation of snow and rain around the world. All species and strains of Pseudomonas have historically been classified as strict aerobes . Exceptions to this classification have recently been discovered in Pseudomonas biofilms . A significant number of cells can produce exopolysaccharides associated with biofilm formation. Secretion of exopolysaccharides such as alginate makes it difficult for pseudomonads to be phagocytosed by mammalian white blood cells . Exopolysaccharide production also contributes to surface-colonising biofilms that are difficult to remove from food preparation surfaces. Growth of pseudomonads on spoiling foods can generate

9398-737: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

9525-536: The genomes of hundreds of strains revealed highly divergent species within the genus. In fact, many genomes of Pseudomonas share only 50-60% of their genes, e.g. P. aeruginosa and P. putida share only 2971 proteins out of 5350 (or ~55%). By 2020, more than 500 complete Pseudomonas genomes were available in Genebank. A phylogenomic analysis utilized 494 complete proteomes and identified 297 core orthologues, shared by all strains. This set of core orthologues at

9652-478: The genus Pseudomonas are now classified in the genera Burkholderia and Ralstonia . In 2020, a phylogenomic analysis of 494 complete Pseudomonas genomes identified two well-defined species ( P. aeruginosa and P. chlororaphis ) and four wider phylogenetic groups ( P. fluorescens, P. stutzeri, P. syringae, P. putida ) with a sufficient number of available proteomes. The four wider evolutionary groups include more than one species, based on species definition by

9779-405: The genus an excellent focus for scientific research; the best studied species include P. aeruginosa in its role as an opportunistic human pathogen , the plant pathogen P. syringae , the soil bacterium P. putida , and the plant growth-promoting P. fluorescens , P. lini , P. migulae , and P. graminis . Because of their widespread occurrence in water and plant seeds such as dicots ,

9906-486: The genus display these defining characteristics: Other characteristics that tend to be associated with Pseudomonas species (with some exceptions) include secretion of pyoverdine , a fluorescent yellow-green siderophore under iron-limiting conditions. Certain Pseudomonas species may also produce additional types of siderophore, such as pyocyanin by Pseudomonas aeruginosa and thioquinolobactin by Pseudomonas fluorescens . Pseudomonas species also typically give

10033-680: The genus level was enriched for proteins involved in metabolism, translation, and transcription and was utilized for generating a phylogenomic tree of the entire genus, to delineate the relationships among the Pseudomonas major evolutionary groups. In addition, group-specific core proteins were identified for most evolutionary groups, meaning that they were present in all members of the specific group, but absent in other pseudomonads. For example, several P. aeruginosa -specific core proteins were identified that are known to play an important role in this species' pathogenicity, such as CntL, CntM, PlcB, Acp1, MucE, SrfA, Tse1, Tsi2, Tse3, and EsrC . Members of

10160-401: The immunocompetent, P. aeruginosa typically infects the airway, urinary tract , burns , and wounds , and also causes other blood infections . It is the most common cause of infections of burn injuries and of the outer ear ( otitis externa ), and is the most frequent colonizer of medical devices (e.g., catheters ). Pseudomonas can be spread by equipment that gets contaminated and

10287-481: The intestinal tract and severely damage or kill the host, which can be mitigated by providing excess phosphate instead of antibiotics. In higher plants, P. aeruginosa induces soft rot , for example in Arabidopsis thaliana (Thale cress) and Lactuca sativa (lettuce). It is also pathogenic to invertebrate animals, including the nematode Caenorhabditis elegans , the fruit fly Drosophila , and

10414-633: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

10541-504: The largest genomes, followed by environmental strains, and then clinical isolates. The same comparative study (494 Pseudomonas strains, of which 189 are P. aeruginosa ) identified that 41 of the 1811 P. aeruginosa core proteins were present only in this species and not in any other member of the genus, with 26 (of the 41) being annotated as hypothetical. Furthermore, another 19 orthologous protein groups are present in at least 188/189 P. aeruginosa strains and absent in all

10668-551: The las system defines a hierarchical QS cascade from the las to the rhl regulons. Detection of these molecules indicates P. aeruginosa is growing as biofilm within the lungs of cystic fibrosis patients. The impact of QS and especially las systems on the pathogenicity of P. aeruginosa is unclear, however. Studies have shown that lasR-deficient mutants are associated with more severe outcomes in cystic fibrosis patients and are found in up to 63% of chronically infected cystic fibrosis patients despite impaired QS activity. QS

10795-474: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Pseudomonas aeruginosa Pseudomonas aeruginosa is a common encapsulated , Gram-negative , aerobic – facultatively anaerobic , rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, P. aeruginosa

10922-504: The low permeability of the bacterial cellular envelopes. Besides intrinsic resistance, P. aeruginosa easily develops acquired resistance either by mutation in chromosomally encoded genes or by the horizontal gene transfer of antibiotic resistance determinants. Development of multidrug resistance by P. aeruginosa isolates requires several different genetic events that include acquisition of different mutations and/or horizontal transfer of antibiotic resistance genes. Hypermutation favours

11049-418: The mid-1980s, certain members of the genus Pseudomonas have been applied to cereal seeds or applied directly to soils as a way of preventing the growth or establishment of crop pathogens. This practice is generically referred to as biocontrol . The biocontrol properties of P. fluorescens and P. protegens strains (CHA0 or Pf-5 for example) are currently best-understood, although it is not clear exactly how

11176-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

11303-598: The moth Galleria mellonella . The associations of virulence factors are the same for plant and animal infections. In both insects and plants, P. aeruginosa virulence is highly quorum sensing (QS) dependent. Its QS is in turn highly dependent upon such genes as acyl-homoserine-lactone synthase , and lasI . P. aeruginosa is an opportunistic pathogen with the ability to coordinate gene expression in order to compete against other species for nutrients or colonization. Regulation of gene expression can occur through cell-cell communication or quorum sensing (QS) via

11430-505: The much faster method of polymerase chain reaction (PCR) . Fragments can then be matched with sequences found on bacterial species. Ribotyping is shown to be a method to isolate bacteria capable of spoilage. Around 51% of Pseudomonas bacteria found in dairy processing plants are P. fluorescens , with 69% of these isolates possessing proteases, lipases, and lecithinases which contribute to degradation of milk components and subsequent spoilage. Other Pseudomonas species can possess any one of

11557-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

11684-501: The organism. Clinical identification of P. aeruginosa may include identifying the production of both pyocyanin and fluorescein, as well as its ability to grow at 42 °C. P. aeruginosa is capable of growth in diesel and jet fuels , where it is known as a hydrocarbon -using microorganism , causing microbial corrosion . It creates dark, gellish mats sometimes improperly called " algae " because of their appearance. Many P. aeruginosa isolates are resistant to

11811-532: The other phenazines mentioned above. Though phenazine biosynthesis is well studied, questions remain as to the final structure of the brown phenazine pyomelanin. When pyocyanin biosynthesis is inhibited, a decrease in P. aeruginosa pathogenicity is observed in vitro . This suggests that pyocyanin is mostly responsible for the initial colonization of P. aeruginosa in vivo . With low phosphate levels, P. aeruginosa has been found to activate from benign symbiont to express lethal toxins inside

11938-416: The other strains of the genus. The population of P. aeruginosa can be classified in three main lineages, genetically characterised by the model strains PAO1, PA14, and the more divergent PA7. While P. aeruginosa is generally thought of as an opportunistic pathogen, several widespread clones appear to have become more specialised pathogens, particularly in cystic fibrosis patients, including

12065-644: The plant growth-promoting properties of P. fluorescens are achieved. Theories include: the bacteria might induce systemic resistance in the host plant, so it can better resist attack by a true pathogen; the bacteria might outcompete other (pathogenic) soil microbes, e.g. by siderophores giving a competitive advantage at scavenging for iron; the bacteria might produce compounds antagonistic to other soil microbes, such as phenazine -type antibiotics or hydrogen cyanide . Experimental evidence supports all of these theories. Other notable Pseudomonas species with biocontrol properties include P. chlororaphis , which produces

12192-406: The plasma membrane of eukaryotic cells, leading to lysis . Increasingly, it is becoming recognized that the iron-acquiring siderophore , pyoverdine , also functions as a toxin by removing iron from mitochondria , inflicting damage on this organelle. Since pyoverdine is secreted into the environment, it can be easily detected by the host or predator, resulting the host/predator migration towards

12319-462: The presence of a certain level of resistance. Combination therapy after rigorous antimicrobial susceptibility testing has been found to be the best course of action in the treatment of multidrug-resistant P. aeruginosa . Some next-generation antibiotics that are reported as being active against P. aeruginosa include doripenem, ceftobiprole, and ceftaroline. However, these require more clinical trials for standardization. Therefore, research for

12446-471: The production of adhesive pili , that serve as "anchors" to stabilize the attachment of P. aeruginosa on the surface. At later stages, bacteria will start attaching irreversibly by producing a strongly adhesive matrix. At the same time, cyclic di-GMP represses the synthesis of the flagellar machinery, preventing P. aeruginosa from swimming. When suppressed, the biofilms are less adherent and easier to treat. The biofilm matrix of P. aeruginosa

12573-500: The production of small molecules called autoinducers that are released into the external environment. These signals, when reaching specific concentrations correlated with specific population cell densities, activate their respective regulators thus altering gene expression and coordinating behavior. P. aeruginosa employs five interconnected QS systems   – las, rhl, pqs, iqs, and pch   – that each produce unique signaling molecules. The las and rhl systems are responsible for

12700-479: The proteases, lipases, or lecithinases, or none at all. Similar enzymatic activity is performed by Pseudomonas of the same ribotype, with each ribotype showing various degrees of milk spoilage and effects on flavour. The number of bacteria affects the intensity of spoilage, with non-enzymatic Pseudomonas species contributing to spoilage in high number. Food spoilage is detrimental to the food industry due to production of volatile compounds from organisms metabolizing

12827-503: The proteins secreted by P. aeruginosa . The bacterium possesses a wide range of secretion systems , which export numerous proteins relevant to the pathogenesis of clinical strains. Intriguingly, several genes involved in the pathogenesis of P. aeruginosa, such as CntL, CntM, PlcB, Acp1, MucE, SrfA, Tse1, Tsi2, Tse3, and EsrC are core group-specific, meaning that they are shared by the vast majority of P. aeruginosa strains, but they are not present in other Pseudomonads . P. syringae

12954-467: The proteome. The higher percentage of aeruginosa-core proteins in this latter analysis could partly be attributed to the use of complete genomes. Although P. aeruginosa is a very well-defined monophyletic species, phylogenomically and in terms of ANIm values, it is surprisingly diverse in terms of protein content, thus revealing a very dynamic accessory proteome, in accordance with several analyses. It appears that, on average, industrial strains have

13081-541: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

13208-417: The response of P. aeruginosa populations to antibiotic treatment. Although gallium has no natural function in biology, gallium ions interact with cellular processes in a manner similar to iron(III). When gallium ions are mistakenly taken up in place of iron(III) by bacteria such as Pseudomonas , the ions interfere with respiration, and the bacteria die. This happens because iron is redox-active, allowing

13335-644: The response of P. aeruginosa populations to antibiotic treatment. Mechanisms underlying antibiotic resistance have been found to include production of antibiotic-degrading or antibiotic-inactivating enzymes, outer membrane proteins to evict the antibiotics, and mutations to change antibiotic targets. Presence of antibiotic-degrading enzymes such as extended-spectrum β-lactamases like PER-1, PER-2, and VEB-1, AmpC cephalosporinases, carbapenemases like serine oxacillinases, metallo-b-lactamases, OXA-type carbapenemases, and aminoglycoside-modifying enzymes, among others, have been reported. P. aeruginosa can also modify

13462-437: The responsible Pseudomonas species. The gas sensor consists of a nose portion made of 14 modifiable polymer sensors that can detect specific milk degradation products produced by microorganisms. Sensor data is produced by changes in electric resistance of the 14 polymers when in contact with its target compound, while four sensor parameters can be adjusted to further specify the response. The responses can then be pre-processed by

13589-470: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

13716-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

13843-430: The selection of mutation-driven antibiotic resistance in P. aeruginosa strains producing chronic infections, whereas the clustering of several different antibiotic resistance genes in integrons favours the concerted acquisition of antibiotic resistance determinants. Some recent studies have shown phenotypic resistance associated to biofilm formation or to the emergence of small-colony-variants, which may be important in

13970-427: The selection of mutation-driven antibiotic resistance in P. aeruginosa strains producing chronic infections, whereas the clustering of several different antibiotic resistance genes in integrons favors the concerted acquisition of antibiotic resistance determinants. Some recent studies have shown phenotypic resistance associated to biofilm formation or to the emergence of small-colony variants may be important in

14097-545: The seventh edition of Bergey's Manual of Systematic Bacteriology (the main authority in bacterial nomenclature) as Greek pseudes (ψευδής) "false" and -monas (μονάς/μονάδος) "a single unit", which can mean false unit; however, Migula possibly intended it as false Monas , a nanoflagellated protist (subsequently, the term "monad" was used in the early history of microbiology to denote unicellular organisms). Soon, other species matching Migula's somewhat vague original description were isolated from many natural niches and, at

14224-480: The siderophores does not necessarily receive the direct benefit of iron intake. Rather, all members of the cellular population are equally likely to access the iron-siderophore complexes. Members of the cellular population that can efficiently produce these siderophores are commonly referred to as cooperators; members that produce little to no siderophores are often referred to as cheaters. Research has shown when cooperators and cheaters are grown together, cooperators have

14351-508: The small is found in nature. The third, however, is present in biological settings and has been found in respiratory and in the urinary tract. Furthermore, mutations in the gene lasR drastically alter colony morphology and typically lead to failure to hydrolyze gelatin or hemolyze. In certain conditions, P. aeruginosa can secrete a variety of pigments, including pyocyanin (blue), pyoverdine (yellow and fluorescent ), pyorubin (red), and pyomelanin (brown). These can be used to identify

14478-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

14605-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

14732-469: The targets of antibiotic action: for example, methylation of 16S rRNA to prevent aminoglycoside binding and modification of DNA, or topoisomerase to protect it from the action of quinolones. P. aeruginosa has also been reported to possess multidrug efflux pumps systems that confer resistance against a number of antibiotic classes, and the MexAB-OprM ( Resistance-nodulation-division ( RND ) family)

14859-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

14986-2102: The taxonomy of many bacterial species previously classified as being in the genus Pseudomonas . Species removed from Pseudomonas are listed below; clicking on a species will show its new classification. The term 'pseudomonad' does not apply strictly to just the genus Pseudomonas , and can be used to also include previous members such as the genera Burkholderia and Ralstonia . α proteobacteria: P. abikonensis , P. aminovorans , P. azotocolligans , P. carboxydohydrogena , P. carboxidovorans , P. compransoris , P. diminuta , P. echinoides , P. extorquens , P. lindneri , P. mesophilica , P. paucimobilis , P. radiora , P. rhodos , P. riboflavina , P. rosea , P. vesicularis . β proteobacteria: P. acidovorans , P. alliicola , P. antimicrobica , P. avenae , P. butanovora , P. caryophylli , P. cattleyae , P. cepacia , P. cocovenenans , P. delafieldii , P. facilis , P. flava , P. gladioli , P. glathei , P. glumae , P. huttiensis , P. indigofera , P. lanceolata , P. lemoignei , B. mallei , P. mephitica , P. mixta , P. palleronii , P. phenazinium , P. pickettii , P. plantarii , P. pseudoflava , B. pseudomallei , P. pyrrocinia , P. rubrilineans , P. rubrisubalbicans , P. saccharophila , P. solanacearum , P. spinosa , P. syzygii , P. taeniospiralis , P. terrigena , P. testosteroni . γ-β proteobacteria: P. boreopolis , P. cissicola , P. geniculata , P. hibiscicola , P. maltophilia , P. pictorum . γ proteobacteria: P. beijerinckii , P. diminuta , P. doudoroffii , P. elongata , P. flectens , P. marinus , P. halophila , P. iners , P. marina , P. nautica , P. nigrifaciens , P. pavonacea , P. piscicida , P. stanieri . δ proteobacteria: P. formicans . The following relationships between genomic affinity groups have been determined by phylogenetic analysis : Pseudomonas fluorescens group Genus The composition of

15113-456: The time, many were assigned to the genus . However, many strains have since been reclassified, based on more recent methodology and use of approaches involving studies of conservative macromolecules. Recently, 16S rRNA sequence analysis has redefined the taxonomy of many bacterial species. As a result, the genus Pseudomonas includes strains formerly classified in the genera Chryseomonas and Flavimonas . Other strains previously classified in

15240-443: The topic is ongoing. In 2013, João Xavier described an experiment in which P. aeruginosa , when subjected to repeated rounds of conditions in which it needed to swarm to acquire food, developed the ability to "hyperswarm" at speeds 25% faster than baseline organisms, by developing multiple flagella , whereas the baseline organism has a single flagellum. This result was notable in the field of experimental evolution in that it

15367-415: The transfer of electrons during respiration, while gallium is redox-inactive. Infectious species include P. aeruginosa , P. oryzihabitans , and P. plecoglossicida . P. aeruginosa flourishes in hospital environments, and is a particular problem in this environment, since it is the second-most common infection in hospitalized patients ( nosocomial infections ). This pathogenesis may in part be due to

15494-428: The vague description, the type species, Pseudomonas pyocyanea ( basionym of Pseudomonas aeruginosa ), proved the best descriptor. Like most bacterial genera, the pseudomonad last common ancestor lived hundreds of millions of years ago. They were initially classified at the end of the 19th century when first identified by Walter Migula . The etymology of the name was not specified at the time and first appeared in

15621-576: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

15748-418: The various nutrients found in the food product. Contamination results in health hazards from toxic compound production as well as unpleasant odours and flavours. Electronic nose technology allows fast and continuous measurement of microbial food spoilage by sensing odours produced by these volatile compounds. Electronic nose technology can thus be applied to detect traces of Pseudomonas milk spoilage and isolate

15875-534: The virulent nature of P. aeruginosa . LigDs form a subfamily of the DNA ligases . These all have a LigDom/ligase domain, but many bacterial LigDs also have separate polymerase domains/PolDoms and nuclease domains/NucDoms. In P. aeruginosa ' s case the nuclease domains are N-terminus , and the polymerase domains are C-terminus , extensions of the single central ligase domain. Frequently acting as an opportunistic , nosocomial pathogen of immunocompromised individuals, but capable of infecting

16002-497: The virulent strain Pseudomonas tolaasii is responsible for causing blight and degradation in edible mushroom species. One way of identifying and categorizing multiple bacterial organisms in a sample is to use ribotyping. In ribotyping, differing lengths of chromosomal DNA are isolated from samples containing bacterial species, and digested into fragments. Similar types of fragments from differing organisms are visualized and their lengths compared to each other by Southern blotting or by

16129-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

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