Plesiomonas shigelloides is an oxidase-positive, Gram-negative rod currently allocated to the family Vibrionaceae but which is more closely related to the family Enterobacteriaceae[]. Upozornenie: Prezeranie tchto strnok je uren len pre nvtevnkov nad 18 rokov! A locked padlock) or https:// means youve safely connected to the .gov website. Plesiomonas shigelloides is a species of bacteria that was formerly classified in the family Vibrionaceae, but now most microbiologists agree that a better classification is in the order Enterobacterales (see box on the right). Plesiomonas shigelloides (formerly known Aeromonas shigelloides) is an oxidase-positive, facultatively anaerobic gram-negative bacillus commonly found in aquatic environments. Biochemical characteristics and a simple scheme for the identification of Aeromonas species and Plesiomonas shigelloides. Plesiomonas can be distinguished from Shigella in diarrheal stools by an oxidase test: Plesiomonas is oxidase positive and Shigella is oxidase negative. Plesiomonas shigelloides is an oxidase-positive, gram-negative rod that has been implicated as an agent of human gastroenteritis for almost 40 years. A locked padlock) or https:// means youve safely connected to the .gov website. P. rettgeri can be incubated at 37 C in nutrient agar or nutrient broth.It was first discovered in 1904 after a waterfowl epidemic. Plesiomonas shigelloides is an oxidase-positive, gram-negative rod that has been implicated as an agent of human gastroenteritis for almost 40 years and is widely distributed in the environment. nonhemolytic on sheep blood agar. Gram-negative lactose fermenters will produce red colonies while non-fermenters will produce white/colorless colonies. Have lophotrichous flagella. Citrobacter freundii is a species of facultative anaerobic Gram-negative bacteria of the family Enterobacteriaceae which currently consists of 13 recognized species. Like B. bronchiseptica, B. pertussis is motile and expresses a flagellum-like structure. Plesiomonas shigelloides is a species of bacteria that was formerly classified in the family Vibrionaceae, but now most microbiologists agree that a better classification is in the family Enterobacteriaceae (see box on the right).It is a Gram-negative, rod-shaped bacterium which has been isolated from freshwater, freshwater fish, and shellfish and from many types of animals P. shigelloides has been increasingly recognized as an enteric pathogen [] and as a causative agent of various extra-intestinal infections such as septicaemia, meningitis, SYNOPSIS Plesiomonasshigelloides, a motile, oxidase-positive, PLESIOMONAS SHIGELLOIDES IN CHILDREN WITH ENTERITIS No.of No.Positive Comments Faecal for Pies. Plesiomonas shigelloides is an oxidase-positive, Production of indole was observed on the MIO medium and the test for oxidase was performed on picks from LIA on filter paper with tetramethyl-p-phenylenediamine (4). Plesiomonas is easily differentiated from Aeromonas sp. 1.Aeromonas spp; P. shigelloides; Y. enterocolitica ;Listeria monocytogenes (rare); Clostridium perfringens; 2.Steps in the Investigation an outbreak of food poisoning : 3.Food hygiene and safety 1.ELISA for the detection of exotoxins . Pseudomonas aeruginosa is a common encapsulated, Gram-negative, strict aerobic (although can grow anaerobically in the presence of nitrate), Rod-shaped bacterium that can cause disease in plants and animals, including humans. Lysine-, Ornithine-, and Arginine-Decarboxylase-positive. Cultures shigelloides 3 2 31 11 1 6 12 3 4 16 3 4 2 11 5S 11 3 3 3 3 5 Test No.Positiveoutof No.Tested Motility Acidin glucose (aerobic, 1 day) The organism moves by polar flagella which are lophotrichous, meaning they have multiple flagella in the same area. A. Distinguish from Shigella spp. These bacteria have a rod shape with a typical length of 15 m. Lipase-negative. UpToDate, electronic clinical resource tool for physicians and patients that provides information on Adult Primary Care and Internal Medicine, Allergy and Immunology, Cardiovascular Medicine, Emergency Medicine, Endocrinology and Diabetes, Family Medicine, Gastroenterology and Hepatology, Hematology, Infectious Diseases, Nephrology and Hypertension, Neurology, On initial isolation, V. parahaemolyticus may be confused with Aeromonas hydrophila, Plesiomonas shigelloides, and Pseudomonas spp. Sucrose-fermenting Proteus spp. P. shigelloides has been isolated from a variety of environmental sources, primarily aquatic , and is distributed worldwide.Moreover, P. shigelloides has been associated with seafood It does not ferment lactose, but could be variable. Plesiomonas shigelloides MICROSCOPIC APPEARANCE MACROSCOPIC APPEARANCE Colonies appear grayish, shiny, opaque with a smooth surface. Catalase-positive. The biochemical characteristics of 55 strains of Aeromonas spp. Most C. freundii cells have several flagella used for locomotion, although some non-motile taxa do not.C. It is also a significant pathogen causing mainly intestinal diseases in humans. Plesiomonas is easily differentiated from Aeromonas sp. A. Catalase B. fermentation of lactose C. oxidase D. beta hemolysis. Microbiology. Citrobacter freundii is a species of facultative anaerobic Gram-negative bacteria of the family Enterobacteriaceae which currently consists of 13 recognized species. Smooth gray colonies showing no hemolysis are recovered from an infected cat scratch on blood and chocolate agar but fail to grow on MacConkey agar. oxidase test is most helpful in screening colonies suspected of being one of the family enterobacteriaceae (all negative except plesiomonas shigelloides which is positive) and in identifying colonies suspected of belonging to other genera such as pseudomonas, aeromonas, vibrio, brucella, haemophilus, alcaligenes, neisseria, campylobacter, and Jump search Burkholderia pseudomalleiBurkholderia pseudomallei colonies Ashdown agar showing the characteristic cornflower head morphologyScientific classification Domain BacteriaPhylum PseudomonadotaClass BetaproteobacteriaOrder BurkholderialesFamily BurkholderiaceaeGenus BurkholderiaSpecies pseudomalleiBinomial nameBurkholderia Laboratory diagnosis of Plesiomonas shigelloides: P. shigelloides is a straight-to-rounded, short, Gram-negative bacteria. These bacteria have a rod shape with a typical length of 15 m. Because of this, the bacteria generally move in one direction. Download Citation | Plesiomonas shigelloides: An emerging pathogen with unusual properties | Plesiomonas shigelloides is a Gram-negative, motile and oxidase-positive bacterium that is Some Plesiomonas strains share antigens with Shigella sonnei, and cross-reactions with Shigella antisera occur. A variation on this test using Ehrlichs reagent (using ethyl alcohol in place of isoamyl alcohol, developed by Paul Ehrlich) is used when performing the test on non-fermenters and anaerobes. It is widely distributed in soil and water. The test is used as an aid for the differentiation of Neisseria, Moraxella, Campylobacter and Pasteurella species (oxidase positive). TCBS is an unsatisfactory medium for oxidase testing of Vibrio spp. Plesiomonas shigelloides is a species of bacteria that was formerly classified in the family Vibrionaceae, but now most microbiologists agree that a better classification is in the order Enterobacterales (see box on the right). Pasteurella spp. We show that some of these domains were likely acquired or maintained due to the ecological niche of P. shigelloides. To test this, a quick oxidase test for cytochrome c oxidase may be performed. Although originally placed in the family Vibrionaceae (), which also included the genera Vibrio, Photobacterium, and Plesiomonas, subsequent phylogenetic investigations indicated that the genus Aeromonas is not closely related to vibrios but rather forms a monophyletic unit in The research started with fish rearing (40 days) and was followed by a challenged test (14 days). Serious Plesiomonas (Aeromonas) shigelloides infections have rarely been reported, and have probably been missed because this organism is very similar to the Enterobacteriaceae in associated clinical disease, and in properties investigated in the diagnostic laboratory. Compositions and methods for detecting Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are provided.The present invention also provides methods and compositions for screening for infection /inflammation based on genomic copy number.Described herein is a method that entails assaying a sample obtained from the urogenital tract of the mammal for an indicator of Determination of complement role To verify dependence on serum bacterial activity, sera were inactivated at 560C for 30 mins. L. pneumophila is the primary human pathogenic bacterium in this group and is the causative agent of Legionnaires' disease, also known as legionellosis.. Results of tests for the production of oxidase, acid from xylose, dulcitol, adonitol, mannitol, or inositol; greenish pigmentation on Information and translations of plesiomonas shigelloides in the most comprehensive dictionary definitions resource on the web. May 4, 2022 March 21, 2022 by Sagar Aryal. P. rettgeri is in the genus Providencia, along with Providencia stuartii, Providencia alcalifaciens, and Providencia rustigianii. Modified oxidase Test B. Bacitracin Susceptibility C. Furazolidone Susceptibility D. Penicillin susceptibility. It is also used to differentiate pseudomonads from related species. Flera exempel p versttningar sorterade efter mnesomrde av specifik tillfrd effekt (spi Svenska-Engelska ordbok och den smarta versttningsassistenten. Last updated: August 15, 2019 by Sagar Aryal. P. shigelloides is a facultative, anaerobic, Gram-negative rod weakly related to the species of Enterobacteriaceae and Vibrionaceae. . Oxidase test protocol. Biochemical Test and Identification of Streptococcus pneumoniae. It is a non-fermenter on MacConkey agar but some strains are partial lactose-fermenters. Pick a single isolated colony (from a pure culture) and make a suspension of it in sterile distilled water. The oxidase test is used to determine if an organism possesses the cytochrome oxidase enzyme. It causes the infection of the host cell by sticking to the host cell using trimeric autotransporter adhesins Most C. freundii cells have several flagella used for locomotion, although some non-motile taxa do not.C. The genus Plesiomonas includes a single species, Plesiomonas shigelloides.Although originally classified with Aeromonas as belonging to the family Vibrionaceae, recent evidence based on small subunit ribosomal RNA sequencing has shown that P. shigelloides is more closely related to members of the Enterobacteriaceae (37, 51), with P. mirabilis causes 90% of all Proteus infections in humans. It is oxidase-positive and catalase-positive. and other oxidase-positive organisms by standard biochemical tests. Plesiomonas can be distinguished from Shigella in diarrheal stools by an oxidase test: Plesiomonas is oxidase positive and Shigella is oxidase negative. Grows at the incubation of 24 hours at 30C- 35C. Principle of Indole Test. In presence of the enzyme cytochrome oxidase (gram-negative bacteria), the N,N-dimethyl-p-phenylenediamine oxalate and -naphthol react to indophenol blue. Most strains are sensitive to vibriostatic agent 0/129. Using tweezers, place an oxidase disk on a slide. A species of facultatively anaerobic, Gram-negative, rod shaped bacteria in the phylum Proteobacteria. wikipedia When performing the oxidase test, which of the following would not be appropriate? Plesiomonas shigelloides is a motile, oxidase-positive, facultatively anaerobic, gram-negative rod bacterium, which is presently classified in the family Vibrionaceae. This species is motile, oxidase, catalase, ornithine and lysine decarboxylase, and arginine dihydrolase positive, Voges-Proskauer test negative, reduces nitrate, but does not hydrolyze urea or liquefy gelatin. Transport: 4C or frozen L. monocytogenes Tumbling motility: head over heels/end-to-end motility Listeriolysin O Infections:-Granulomatosis infantiseptica-Meningitis Lab. Plesiomonas can be distinguished from Shigella in diarrheal stools by an oxidase test: Plesiomonas is oxidase positive and Shigella is oxidase negative. Plesiomonas shigelloides is a species of bacteria that was formerly classified in the family Vibrionaceae, but now most microbiologists agree that a better classification is in the order Enterobacterales (see box on the right).It is a Gram-negative, rod-shaped bacterium which has been isolated from freshwaterGram-negative, rod-shaped bacterium which Global Biodiversity Information Facility. It is an important pathogen of fish and has been implicated as a cause of enteric disease in humans, especially following the consumption of raw seafood. Share sensitive information only on official, secure websites. Infection with this type of pathogenic bacteria may lead to hemorrhagic diarrhea, and to Oxidase Test Principle. Science; Biology; Biology questions and answers; can someone tell me the results for these organisms in a gram test, oxidase test, 6% naCl test, and phenol red sucrose test : (just indicate if positive or negative) Vibrio parahaemolyticus, Plesiomonas shigelloides, Shigella flexneri, Yersinia enterocolitica, Vibrio cholerae, Aeromonas hydrophila, Alcaligenes faecalis, P. shigelloides is naturally found in fresh water and other Non-lactose fermenting, oxidase positive. A one-minute oxidase test to detect Vibrio strains isolated from cultures on thiosulphate-citrate-bile salts-sucrose (TCBS) medium Vibrio cholerae is oxidase positive, a primary characteristic used to differentiate it from Enterobacteriaceae. Negative (-ve) The oxidase test is a technique for detecting the presence of the terminal enzyme system in aerobic respiration called cytochrome C oxidase or cytochrome a3. grows well on sheep blood agar and most enteric media. Oxidase test is most helpful in screening colonies suspected of being one of the family Enterobacteriaceae (all negative except Plesiomonas shigelloides which is positive) and in identifying colonies suspected of belonging to other genera such as Pseudomonas, Sign Up She had been suffering with sharp epigastric pain. 162 Plesiomonas can be found in aquatic environments in addition to various fish, birds, and mammals. It is placed among the Enterobacteriaceae. The regent used is o-nitrophenyl-B-D-galactopyranoside. A locked padlock) or https:// means youve safely connected to the .gov website. by oxidase test; distinguished from Aeromonas by negative DNAse testing. Sucrose-fermenting Proteus spp. Purpose of the Test. Plesiomonas can be distinguished from Shigella in diarrheal stools by an oxidase test: Plesiomonas is oxidase positive and Shigella is oxidase negative. A case of overwhelming neonatal meningitis and sepsis is discussed, and the use of the simple produce yellow colonies which may resemble those of Vibrio. O Scribd o maior site social de leitura e publicao do mundo. Plesiomonas shigelloides (family Enterobacteriaceae) has been implicated in gastroenteritis outbreaks in travelers to tropical regions and in persons who have ingested contaminated food or water (13).For persons native to tropical regions, however, casecontrol studies have found little or no association between P. shigelloides infection and diarrhea (46). The structure of the two central domains (23) of RctB is similar with, and common among, plasmid replication initiators (Orlova et al. Final identification of suspected pathogens was performed using standard biochemical tests (4), not API system. Basic Characteristics. Enter the email address you signed up with and we'll email you a reset link. Tryptophan is an amino acid that can undergo deamination and hydrolysis by bacteria that express tryptophanase enzyme. Campylobacter is a helical-shaped, non-spore-forming, Gram-negative, microaerophilic, nonfermenting motile bacterium with a single flagellum at one or both poles, which are also oxidase-positive and grow optimally at 37 to 42 C. P. mirabilis causes 90% of all Proteus infections in humans. Zsady ochrany osobnch dajov. It is a soil bacterium that causes rare infections in humans, and is often multi-drug Principle. freundii is a soil-dwelling microorganism, Anaplasma phagocytophilum (formerly Ehrlichia phagocytophilum) is a Gram-negative bacterium that is unusual in its tropism to neutrophils.It causes anaplasmosis in sheep and cattle, also known as tick-borne fever and pasture fever, and also causes the zoonotic disease human granulocytic anaplasmosis.. A. phagocytophilum is a Gram-negative, obligate bacterium of neutrophils. The percentage lysis was expressed as the intensity (w/v) of oxidase released from the labeled bacteria into the supernate. The biopsy of the ulcer revealed curved baccili with 2.Molecular diagnostic tools to detect foodborne pathogens like Diarrhoeagenic E.coli Plesiomonas shigelloides Contains a RctB-Chromid. The bacteria are oxidase positive and show non-lactose fermentation on MacConkey agar. Oxidase + - MAC + NLF 42 C - 0/120 vibriostatic disk vibrio & plesiomonas are Sensitive TCBS agar thiosulfate citrate bile salts sucrose- transport media- Carey Blair. Meaning of plesiomonas shigelloides. Properties (Streptococcus pneumoniae) Bile Solubility. Choose a colony that is well isolated and representative of the fresh culture to be tested. This oxidase test is useful in the initial characterization of gram-negative bacteria. Login . {{configCtrl2.info.metaDescription}} Sign up today to receive the latest news and updates from UpToDate. Share sensitive information only on official, secure websites. Oxidase-labelled P. shigelloides incubated in inactivated normal human serum was used as a control. Plesiomonas shigelloides is a Gram-negative, mobile, non-spore-forming, facultatively anaerobic, and oxidase-positive bacillus. Plesiomonas is negative for DNAse, and this and other biochemical tests distinguish it from Aeromonas sp. Information and translations of plesiomonas shigelloides in the most comprehensive dictionary definitions resource on the web. Which of the following tests can easily differentiate Plesiomonas shigelloides from other members of family Enterobacteriaceae? Free and Open Access to Biodiversity Data. Moraxella catarrhalis is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system, and joints of humans. Procedure of Oxidase Test freundii is a soil-dwelling microorganism, 2017). A nichrome wire loop should be used to acquire inoculum for testing. KEY BIOCHEMICAL REACTIONS Oxidase-positive. Introduction. The pain was accompanied by mild nausea and was relieved by food or antacids. Note: All the members of the family Enterobacteriaceae are oxidase negative except Plesiomonas shigelloides which is oxidase test positive. In nature, L. pneumophila infects freshwater and soil amoebae of the genera Plesiomonas shigelloides, a ubiquitous freshwater inhabitant, has been implicated as a cause of acute diarrhea and, rarely, serious extraintestinal disease. Tilapia fingerlings were challenged by A. hydrophila at Positive (+ve) Catalase. produce yellow colonies which may resemble those of Vibrio. It is a Gram-negative, rod-shaped bacterium which has been isolated from freshwater, freshwater fish, shellfish, cattle, goats, swine, cats, dogs, Pouvanm tohto webu shlaste s uchovvanm cookies, ktor slia na poskytovanie sluieb, nastavenie reklm a analzu nvtevnosti. On initial isolation, V. parahaemolyticus may be confused with Aeromonas hydrophila, Plesiomonas shigelloides, and Pseudomonas spp. Share sensitive information only on official, secure websites. Table 2 analyzed showing the relevance to marine ecosystem particularly when Distribution of Aeromonas and Plesiomonas shigelloides isolated from bivalve associated to the risks for human health (handlers, fisheries, swimmers mollusks in Guanabara Bay (Brazil) and seafood consumers) after exposure to aquatic environment. gastroenteritis from shellfish. optimum growth temperature is 30C. Login Proteus mirabilis can migrate across the surface of solid media or devices using a type of cooperative group motility called swarming. Plesiomonas shigelloides is a species of bacteria that was formerly classified in the family Vibrionaceae, Plesiomonas can be distinguished from Shigella in diarrheal stools by an oxidase test: Plesiomonas is oxidase positive and Shigella is oxidase negative. Currently, molecular studies indicate that it is a species close phylogenetically to the genus Proteus, so it has been classified within the family Enterobacteriaceae, although it had previously been included in the What does plesiomonas shigelloides mean? When exposed to atmospheric oxygen, C. jejuni is able to change into a coccal form. A. and other oxidase-positive organisms by standard biochemical tests. Plesiomonas Plesiomonas shigelloides'' 319-73 Plesiomonas shigelloides is a species of bacteria that was formerly classified in the family Vibrionaceae, but now most microbiologists agree that a better classification is in the order Enterobacterales (see box on the right). 2. Motile. Proteus mirabilis can migrate across the surface of solid media or devices using a type of cooperative group motility called swarming. However, one FDA-approved PCR-based culture-independent diagnostic test system to detect multiple enteropathogens (FilmArray) includes P. shigelloides on its panel. Jump search Species bacteriumCampylobacter jejuniScientific classification Domain BacteriaPhylum CampylobacterotaClass Campylobacteria Order CampylobacteralesFamily CampylobacteraceaeGenus CampylobacterSpecies jejuniBinomial nameCampylobacter jejuni Jones al., 1931 Veron Chatelain, 1973Campylobacter jejuni kmplobktr dduni one Enter the email address you signed up with and we'll email you a reset link. These tests include fermentation of d -arabitol and d -xylose, mucate utilization, and failure to produce cytochrome oxidase and acid from trehalose. Plesiomonas shigelloides. Plesiomonas shigelloides is a gram-negative, facultatively anaerobic bacillus that belongs to the family Enterobacteriaceae as the only oxidase-positive member. Indole-positive. C. Colonies from sheep blood agar can be used. Bordetella pertussis is a Gram-negative, aerobic, pathogenic, encapsulated coccobacillus of the genus Bordetella, and the causative agent of pertussis or whooping cough. GNR. gram =, red long filamentous. The string test (110) is a useful presumptive test for suspected V. cholerae as all strains are positive. The most common atypical biochemical characteristics observed included fermentation of l -rhamnose, d Which is the best rapid test to differentiate Plesiomonas shigelloides from a Shigella species on selective enteric agar? Proteus mirabilis is a Gram-negative, facultatively anaerobic, rod-shaped bacterium.It shows swarming motility and urease activity. and 16 P. shigelloides of human faecal origin were examined. Oxidase Test is based on the principle that certain bacteria produce indophenol blue from the oxidation of dimethyl-p-phenylenediamine and -naphthol. Home Biochemical Test Biochemical Test of Aeromonas hydrophila. Diarrhoea is the leading symptom of most of these infections and may occur as a watery, invasive and chronic form. TCBS is an unsatisfactory medium for oxidase testing of Vibrio spp. In the presence of cytochrome oxidase, N, N, N , N-Tetramethyl-p-phenylenediamine dihydrochloride (colorless) forms a compound. Plesiomonas shigelloides is a Gram-negative, motile and oxidase-positive bacterium that is widely distributed in nature. Acinetobacter baumannii complex is a Gram-negative coccobacillus that is oxidase-negative, indole negative, catalase positive, and exhibits twitching motility in wet mount, though it is nonmotile in motility agar. Biochemical Test of Aeromonas hydrophila. Outbreaks have occurred from poorly prepared seafood. B. Plesiomonas shigelloides is a species of bacteria that was formerly classified in the family Vibrionaceae, but now most microbiologists agree that a better classification is in the order Enterobacterales (see box on the right).It is a Gram-negative, rod-shaped bacterium which has been isolated from freshwaterGram-negative, rod-shaped bacterium which 1 Introduction. Plesiomonas shigelloides biochemical tests & other tests It is a catalase-positive, oxidase-positive, and indole-positive. Escherichia coli O157:H7 is a serotype of the bacterial species Escherichia coli and is one of the Shiga-like toxinproducing types of E. coli.It is a cause of disease, typically foodborne illness, through consumption of contaminated and raw food, including raw milk and undercooked ground beef. (Frosch and Kolle 1896) Henriksen and Bvre 1968. Usually, the family Enterobacteriaceae gives a negative result, whereas Pseudomonas spp, Aeromonas spp, Vibrio spp, and Neisseria spp give a positive result. The name Plesiomonas, from the Greek word for neighbor , was chosen because the organism was believed to be closely related to Aeromonas. Plesiomonas shigelloides is an oxidase-positive, gram-negative, as indole test, citrate utilization, urea production, Kligler iron agar, mannitol La Biblioteca Virtual en Salud es una coleccin de fuentes de informacin cientfica y tcnica en salud organizada y almacenada en formato electrnico en la Regin de Amrica Latina y el Caribe, accesible de forma universal en Internet de modo compatible con Reports of gastroenteritis It is a Gram-negative, rod-shaped bacterium which has been isolated from freshwater, freshwater fish, shellfish, cattle, goats, swine, cats, dogs, monkeys, vultures, snakes, toads and humans. Plesiomonads produce -lactamases but are typically susceptible to many first-line antimicrobial agents, including quinolones and carbapenems. A 49 year old woman presented to the ER complaining the she had vomited up blood at home. Informacin 02-08-2018. Proteus mirabilis is a Gram-negative, facultatively anaerobic, rod-shaped bacterium.It shows swarming motility and urease activity. Providencia rettgeri (commonly P. rettgeri), is a Gram negative bacterium that is commonly found in both water and land environments. Subscribe us to receive latest notes. Previously known as Aeromonas shigelloides. oxidase test is most useful in screening colonies suspected of being one of the family enterobacteriaceae (all negative except plesiomonas shigelloides which is positive) and in identifying colonies suspected of belonging to other genera such as pseudomonas, aeromonas, vibrio, brucella, haemophilus, alcaligenes, neisseria, campylobacter, and She had a long history of peptic ulcer disease at was initially diagnosed with duodenal ulcer at 16. It is widely distributed in soil and water. An oxidase test should not be performed from an enteric medium as acid production from sugars in these media can give a false negative reaction. - catalase and oxidase positive, reduce nitrate to nitrite (except V. metschnikovii) (0/129), positive string test, halophilic Vibrio 5 Vibriostat disk (0/129) 0/129 = 2,4-diamino-6,7-diisopropylpteridine susceptibility differentiates Vibrio from Aeromonas 6 Differentiating Plesiomonas shigelloides - oxidase + rules out Enterobacteriaceae The genus Aeromonas has undergone a number of taxonomic and nomenclature revisions over the past 15 years. Legionella pneumophila is a thin, aerobic, pleomorphic, flagellated, non-spore-forming, Gram-negative bacterium of the genus Legionella.