VIBRIO

• Vibrio, Aeromonas, and Plesiomonas

  Species that are all oxidase-positive, glucose-fermenting, gram-negative bacilli capable of growth on MacConkey agar
• Vibrio, Aeromonas, and Plesiomonas

  • Gram stain reaction
  • Oxidase activity
  • O/129 Susceptibility
  • Growth on TCBS agar
  • 0% NaCl
  • 6.5% NaCl
  • Acid from Glucose
  • Acid from Inositol
  • Acid from Mannitol
  • Acid from Sucrose
  • Gelatin liquefaction
• Vibrio


  • Family Vibrionaceae
  • Aquatic environments, including fresh water, brackish or estuarine water, and marine or salt water
• Vibrio species


  • V. cholerae (serogroups O1 and non-O1)
  • V. parahaemolyticus
  • V. vulnificus
  • V. alginolyticus
• Vibrio species


  • Recent consumption of raw seafood (especially oysters)
  • Recent immigration or foreign travel
  • Gastroenteritis with cholera-like or rice-water stools
  • Accidental trauma incurred during contact with fresh, estuarine, or marine water or associated products
• Clinical Infections Associated With Vibrio Species

  • V. cholerae O1: Cholera, gastroenteritis, wound infections, bacteremia
  • V. cholerae O139: Cholera
  • V. cholerae non-O1: Gastroenteritis, septicemia, brain abscesses, ear infections
  • Vibrio parahaemolyticus: Gastroenteritis, wound infections
  • Vibrio vulnificus: Septicemia, wound infections
  • Vibrio alginolyticus: Wound infections, ear infections, conjunctivitis, respiratory infections, bacteremia
  • Vibrio mimicus: Gastroenteritis, ear infections
  • Vibrio fluvialis: Gastroenteritis
  • Vibrio furnissii: Gastroenteritis
  • Vibrio cincinnatiensis: Meningitis, bacteremia
  • Vibrio metschnikovii: Septicemia, peritonitis
  • Vibrio harveyi: Wound infections
  • Grimontia hollisae: Gastroenteritis
  • Photobacterium damselae: Wound infections (cellulitis; necrotizing fasciitis), bacteremia
• Vibrio species culture


  1. Stool specimens collected and transported in Cary-Blair medium

  2. Specimens for culture consist of mucus flecks from stools

  3. Enrichment in taurocholate-peptone broth (pH 8.0-9.0) or Alkaline Peptone Water broth (pH 8.5)

  4. Subculture to TCBS agar

  
• TCBS agar


  • Contains 1% sodium chloride, bile salts, and sucrose
  • Bromothymol blue and thymol blue pH indicators
  • High pH (8.6) inhibits growth of other intestinal microbiota
  • Differentiates sucrose-fermenting (yellow colonies) from non-sucrose-fermenting (green colonies) Vibrio species
• Vibrio species laboratory tests

  • Facultatively anaerobic
  • Catalase- and oxidase-positive
  • Able to reduce nitrate to nitrite
  • Do not ferment inositol
  • V. cholerae and V. mimicus do not require salt for growth
  • String test to differentiate from Aeromonas
  • Vibrostatic test using 0129 to differentiate Vibrio species

  
• Medically important Vibrio species

  • V. cholerae serogroups O1 and O139: Epidemic and pandemic cholera
  • V. cholerae non-O1/non-O139: Cholera-like diarrhea, mild diarrhea, rarely extraintestinal infection
  • V. parahaemolyticus: Gastroenteritis, perhaps extraintestinal infection
  • Others (V. mimicus, V. vulnificus, V. hollisae, V. fluvialis, V. damsela, V. anginolyticus, V. metschnikovii): Ear, wound, soft tissue, and other extraintestinal infections, all uncommon
• Vibrio cholerae


  • Virulence factors: Cholera toxin, zonula occludens toxin, accessory cholera enterotoxin, O1 and O139 somatic antigens, hemolysin/cytotoxins, motility, chemotaxis, mucinase, toxin coregulated pili
  • Cholera: profuse, watery diarrhea leading to dehydration, hypotension, and often death
  • Rice water stools
  • May also cause nonepidemic diarrhea and extraintestinal infections
  • Rapid darting or shooting-star motility
  • Polar, sheathed flagella when grown in broth, peritrichous, unsheathed flagella when grown on solid media
  • Curved gram-negative rods, can be highly pleomorphic
  • V. cholerae O1 and O139 cause classic cholera, divided into serotypes Ogawa, Inaba, and Hikojima
  • Two biotypes: classic and El Tor
• Vibrio parahaemolyticus


  • Gastroenteritis, food poisoning
  • Requirement of 1% to 8% NaCl
  • Hemolysin production and virulence, known as the Kanagawa phenomenon
  • Produces a heat-stable hemolysin that lyses human erythrocytes in high-salt mannitol medium
• Vibrio vulnificus


  • Primary septicemia and wound infections
  • Organ failure
• Vibrio alginolyticus


  • Least pathogenic for humans
  • Requires at least 1% NaCl, able to tolerate up to 10% NaCl
• Aeromonas


  • Gram-negative straight rods with rounded ends or coccobacillary facultative anaerobes
  • Oxidase and catalase positive, produce acid from oxidative and fermentative metabolism
  • Indole positive
  • Most pathogenic strains are beta-hemolytic except A. caviae, which is usually nonhemolytic
  • Freshwater, estuarine, and marine environments
  • Animal meat products
  • Recognized as enteric pathogens

  
• Aeromonas infections

  • Acute, secretory diarrhea often accompanied by vomiting
  • Acute, dysenteric form of diarrhea (similar to shigellosis), with blood and mucus
  • Chronic diarrhea usually lasting more than 10 days
  • Cholera-like disease, including rice water stools
  • Traveler's diarrhea (similar to enterotoxigenic E. coli)
• Aeromonas caviae


  • Most frequently associated with gastrointestinal infections, especially in neonate and pediatric populations
  • Has been associated with inflammatory bowel disease
• Aeromonads and Plesiomonads
• Aeromonas


  • Coccobacillary facultative anaerobes that occur singly, in pairs, or in short chains
  • Oxidase and catalase positive and produce acid from oxidative and fermentative metabolism
  • Indole positive
  • Most pathogenic strains are beta-hemolytic except Aeromonas caviae, which is usually nonhemolytic
• Environments where Aeromonas is found

  • Freshwater
  • Estuarine
  • Marine
• Sources of Aeromonas infections

  • Animal meat products
• Aeromonas infections


  Recognized as enteric pathogens
• Types of Aeromonas-caused gastroenteritis

  • Acute, secretory diarrhea often accompanied by vomiting
  • Acute, dysenteric form of diarrhea (similar to shigellosis), with blood and mucus
  • Chronic diarrhea usually lasting more than 10 days
  • Cholera-like disease, including rice water stools
  • Traveler's diarrhea (similar to enterotoxigenic E. coli)
• Aeromonas caviae


  The species most frequently associated with gastrointestinal infections, especially in neonate and pediatric populations; it has been associated with inflammatory bowel disease
• Aeromonas culture


  • Aeromonads and Plesiomonads grow well in nutrient broth with 0% NaCl, but not in 6% NaCl
  • For separation of Aeromonads from Plesiomonads, one can use the fermentation of inositol, in which Aeromonads are negative and Plesiomonads are positive
  • Ability to ferment glucose, with or without the production of gas, distinguishes Aeromonas from oxidase positive, nonfermenting Pseudomonas isolates
  • Aeromonas spp. are indistinguishable from Yersinia enterocolitica on modified cefsulodin-irgasan-novobiocin (CIN) agar; therefore, it is important to perform an oxidase test to differentiate the two genera; Aeromonas spp. are oxidase positive
  • Aeromonas agar is a relatively new alternative medium that uses D-xylose as a differential characteristic
• Plesiomonas


  • Oxidase-positive, glucosefermenting, facultatively anaerobic, gram-negative bacilli that are motile by polar flagella
  • Plesiomonas has been moved to the family Enterobacteriaceae but unlike the Enterobacteriaceae, it does not have the ability to produce gas from glucose, it is the only oxidase-positive member, and it is susceptible to agent O/129
• Plesiomonas shigelloides


  • The only species in this genus
  • Fresh water inhabitant that is transmitted to humans by ingestion of contaminated water or by exposure of disrupted skin and mucosal surfaces
  • Causes gastroenteritis, most commonly in children
  • Considered an emerging enteric pathogen associated with food- and water-borne illness
• Plesiomonas culture


  • Gram-negative bacilli that occur singly, in pairs, or in short chains or filamentous forms
  • Motile by monotrichous or two to five lophotrichous flagella
  • Ferment lactose
  • Oxidase positive
  • inositol brilliant green bile agar can enhance the isolation of plesiomonads
  • Plesiomonas colonies are white to pink on this medium, and most coliform colonies are green or pink
  • Will grow on CIN, a selective agar for Yersinia spp., as opaque (non–mannitol-fermenting) colonies with an opaque apron
  • Susceptible to ampicillin

  
• Aeromonas spp. are DNase-positive, and Plesiomonas organisms are DNase-negative
• Sensitivity to the agent O/129 separates Plesiomonas from Aeromonas, and its ability to ferment inositol separates it from all Aeromonas and almost all Vibrio spp.
• Plesiomonas can grow in nutrient broth with 0% NaCl and cannot grow in nutrient broth with 6% NaCl
• Plesiomonas is positive for ornithine and lysine decarboxylases and arginine dihydrolase reactions, combined with the fermentation of inositol
• Campylobacter, Arcobacter, and Helicobacter


  • Campylobacter and Campylobacter-like species, which include Helicobacter and Wolinella, have undergone changes in taxonomy
  • The genera Arcobacter and Sulfurospirillum were placed in the family Campylobacteraceae along with Campylobacter
  • The genera Helicobacter and Wolinella are members of the family Helicobactereaceae

  
• Campylobacters


  • Cause abortion in domestic animals, such as cattle, sheep, and swine and are primarily zoonotic organisms
  • The most common cause of bacterial gastroenteritis worldwide is Campylobacter jejuni: preparing chicken
  • Cause febrile systemic disease, periodontal disease, and, most commonly, gastroenteritis
  • Campylobacter jejuni and Campylobacter coli
  • Transmission has been attributed to direct contact with animals and handling infected pets, such as dogs, cats, and birds, and indirectly by the consumption of contaminated water and dairy products and improperly cooked poultry
  • Campylobacter and Arcobacter spp. are slow growing, fastidious
• Campylobacter and Arcobacter spp., Their Source, and Spectrum of Disease in Humans

  • Campylobacter concisus, Campylobacter curvus, Campylobacter rectus, Campylobacter showae - Humans - Periodontal disease; gastroenteritis (?)
  • Campylobacter gracilis - Humans - Deep-tissue infections: head, neck, and viscera; gingival crevices
  • Campylobacter coli - Pigs, poultry, sheep, bulls, birds - Gastroenteritis*, Septicemia
  • Campylobacter jejuni subsp. jejuni - Poultry, pigs, bulls, dogs, cats, birds, and other animals - Gastroenteritis*, Septicemia, Meningitis, Proctitis
  • Campylobacter jejuni subsp. doylei - Humans - Gastroenteritis*, Gastritis, Septicemia
  • Campylobacter lari - Birds, poultry, other animals; river and seawater - Gastroenteritis*, Septicemia, Prosthetic joint infection
  • Campylobacter hyointestinalis subsp. hyointestinalis - Pigs, cattle, hamsters, deer - Gastroenteritis
  • Campylobacter upsaliensis - Dogs, cats - Gastroenteritis, Septicemia abscesses
  • Campylobacter fetus subsp. fetus - Cattle, sheep - Septicemia, Gastroenteritis, Abortion, Meningitis
  • Campylobacter fetus subsp. venerealis - Cattle - Septicemia
  • Campylobacter plorides - Humans, shell fish - None reported
  • Campylobacter sputorum biovar sputorum - Humans, cattle, pigs - Abscesses, Gastroenteritis
  • Campylobacter ureolyticus - Humans - Dental, oral infections
  • Arcobacter cryaerophilus - Pigs, bulls, and other animals - Gastroenteritis*, Septicemia
  • Arcobacter butzleri - Pigs, bulls, humans, other animals; water - Gastroenteritis*, Septicemia
• Campylobacter laboratory test


  • Feces and blood specimen
  • Cary-Blair transport medium, modified Stuart medium, or campy thio, a thioglycollate broth base with 0.16% agar and vancomycin (10 mg/L), trimethoprim (5 mg/L), cephalothin (15 mg/L), polymyxin B (2500 U/L), and amphotericin B (2 mg/L)
  • Enzyme immunoassays (EIA) - Campylobacter assay and the ImmunoCard Stat! - Campy assay detect both C. jejuni and C. coli
  • Campylobacter spp. are curved, non-spore-forming, gram-negative, may appear as long spirals or 'S' or seagull-wing shapes, have "darting" motility on hanging drop preparations
  • To observe the typical motility, organisms should be suspended in Brucella or tryptic soy broth
  • Typical colony morphology of C. jejuni and other enteric campylobacters is moist, runny looking, and spreading

  
• Selective Media and Incubation Conditions to Recover Campylobacter and Arcobacter spp. from Stool Specimens

  • Modified Skirrow medium, Campy-BA, Blood-free, charcoal-based selective medium, Modified charcoal cefoperazone deoxycholate agar (CCDA), Semisolid motility agar, Campy-CVA - Incubated at 42°C under microaerobic conditions for 72 hours
  • Modified Skirrow medium, Blood-free charcoal-based selective media, Campy-CVA, CCDA, Semisolid motility agar - Incubated at 37°C under microaerobic conditions for at least 72 hours up to 7 days
  • Campy-CVA - Incubated at 37°C under microaerobic conditions for 72 hours
• Campylobacter species


  • ejuni subsp. doylei
  • Campylobacter upsaliensis
  • Campylobacter lari
  • Campylobacter hyointestinalis

  
• Selective media for Campylobacter

  • Modified Skirrow medium
  • Blood-free charcoal-based selective media
  • Campy-CVA
  • CCDA
  • Semisolid motility agar

  
• Campylobacter culture conditions


  37°C under microaerobic conditions for at least 72 hours up to 7 days