Curved, Oxidase positive, Gram-Negative Flashcards
Curved, Oxidase-positive, Gram-negative Bacilli General
Genus Included
Vibrio, Campylobacter, Arcobacter, Helicobacter
General Features: Curved, Oxidase-positive, Gram-negative Bacilli General
Catalase Positive, Oxidase Positive, Agents of Gastroenteritis
Vibrio spp. Characteristics
Gram-negative, Curved/Comma-shaped Bacilli, Catalase Positive, Oxidase Positive, Indole Positive, Glucose Positive, Motile via Polar Flagella, Facultative Anaerobe, Found in Salt/Brackish/Marine Water
Vibrio spp. Halophilic Exception
Vibrio cholerae and Vibrio mimicus are not halophilic
Vibrio spp. Infections
Cholera, Septicemia, Wound Infections
Cholera Pathophysiology
Over secretion of cAMP leading to profuse watery diarrhea, dehydration, and death
Vibrio cholerae Virulence Factors
Choleragen (enterotoxin for cholera), Cholera toxin (CT), Zonula occludens toxin (Zot), Accessory cholera toxin (Ace), O1 and O139 somatic antigens, Hemolysin, Cytotoxin, Flagella, Mucinase, Toxin Coregulated Pili (TCP)
Pandemic Strain of Vibrio cholerae
Pandemic strain: VC-O1, Biotype: El Tor
Serotypes of Vibrio cholerae
Ogawa, Inaba, Hikojima
Specimen Hallmark of Vibrio cholerae
Rice watery stool
Transport Media for Vibrio cholerae
Cary Blair
Enrichment Media for Vibrio cholerae
Alkaline Peptone Water (pH 8.4)
Cultural Media for Vibrio cholerae
Thiosulfate-citrate-bile salts-sucrose (TCBS) (pH 8.6)
Tests for Vibrio cholerae
String test positive, Vibriostatic test (0129-impregnated disk) sensitive
General Genus of Curved, Oxidase Positive, Gram-Negative Bacilli
Vibrio, Campylobacter, Arcobacter, Helicobacter
Gram Negative Curved/Comma-Shaped Bacilli, Catalase, Oxidase, Indole, Glucose Positive, Motile via Polar Flagella, Facultative Anaerobe, Found in Salt/Brackish/Marine Water
Vibrio spp.
All Vibrio spp are halophilic except
V. cholerae and V. mimicus
Infections of Vibrio spp.
Cholera, Septicemia, Wound Infections
Cholera Pathophysiology
Over secretion of cAMP causing profuse watery diarrhea leading to dehydration and death
Associated Condition with Vibrio cholerae
Thrombotic thrombocytopenic purpura
Virulence Factors of Vibrio cholerae
Choleragen (enterotoxin), Cholera toxin (CT), Zonula occludens toxin (Zot), Accessory cholera toxin (Ace), O1 and O139 Somatic antigens, Hemolysin, Cytotoxin, Flagella, Mucinase, Toxin Coregulated Pili (TCP)
Pandemic Strain of Vibrio cholerae
Pandemic strain: VC-O1, Biotypes: El Tor
Serotypes of Vibrio cholerae
Ogawa, Inaba, Hikojima
Specimen Hallmark of Vibrio cholerae
Rice watery stool
Transport Media for Vibrio cholerae
Cary Blair
Enrichment Media for Vibrio cholerae
Alkaline Peptone Water (pH 8.4)
Cultural Media for Vibrio cholerae
TCBS (pH 8.6)
Diagnostic Tests for Vibrio cholerae
String test positive, Vibriostatic test (0129-impregnated disk) sensitive
Sucrose Fermenter; Yellow in TCBS
V. cholerae, V. alginolyticus, V. furnissii, V. fluvialis, V. cincinnatiensis, V. metschnikovii
Non-Sucrose Fermenter; Green in TCBS
V. parahemolyticus, V. vulnificus, V. mimicus
Cholera; Rice water stool
V. cholerae
Otitis, wound infection, gastroenteritis
V. alginolyticus
Summer diarrhea, B-hemolysis in Wagatsuma agar, Kanagawa phenomenon
V. parahemolyticus
Septicemia, wound infection, Lactose +, (ONPG +)
V. vulnificus
Seen in Aquatic environments: Freshwater, polluted, chlorinated, brackish water, occasionally marine water
Aeromonas spp.
Causes Human: Gastroenteritis, wound infection, bacteremia; Reptile: Red-leg syndrome
Aeromonas caviae complex, Aeromonas hydrophila complex
Red man syndrome due to in reptiles
Vancomycin
Gram negative straight bacilli with rounded ends, Oxidase positive, Bull’s eye colonies on CIN, Beta-hemolytic on BAP, Do not grow on TCBS, Not halophilic, grows with 0% NaCl
Aeromonas spp.
Gram-negative Curved/Seagull wing-shaped bacilli, Catalase, Oxidase, Indoxyl acetate Positive
Campylobacter spp.
Campylobacter spp. are microaerophilic and grow at
42°C (hot enrichment method)
Associated with gastroenteritis, reactive arthritis (Reiter syndrome), and Guillain-Barré syndrome
Campylobacter spp.
Improved staining for Campylobacter spp.
0.1% basic fuchsin
Culture media for Campylobacter spp.
Skirrow, CAMPY-CVA, Cefoperazone agar, Charcoal-based selective medium (CSM)
Growth at 32°C and 42°C, Nalidixic acid sensitive, Cephalotin resistant; Hippurate +
C. jejuni
Growth at 32°C and 42°C, Nalidixic acid sensitive, Cephalotin resistant; Hippurate -
C. coli
Source of C. jejuni
Poultry, Pig, Bull, Dog, Cat
Source of C. coli
Poultry, Pig, Bull, Sheep
Growth at 37°C, Nalidixic acid resistant, Cephalotin sensitive, Found in cattle and sheep
C. fetus
Causes gastroenteritis and septicemia
“Arcobacter spp.”
Method to enhance recovery of Campylobacter and Arcobacter in stool samples using 0.45 to 0.65 µm pore size filters
“Filtration method”
Curved Gram-negative bacilli, Oxidase positive, weak Catalase positive, Urease negative
“Arcobacter spp.”
Causes Peptic Ulcer and Peptic Cancer
“Helicobacter pylori”
Virulence factor of H. pylori that produces exotoxin creating vacuoles and loosens tight junctions
“VacA”
Virulence factor of H. pylori that is part of pathogenicity islands causing peptic carcinoma
“CagA”
Virulence factor of H. pylori that binds Leb antigens in gastric epithelial cells
“BabA”
Virulence factor of H. pylori associated with peptic ulcers
“IceA”
Causes gastroenteritis and septicemia
“Arcobacter spp.”
Method to enhance recovery of Campylobacter and Arcobacter in stool samples using 0.45 to 0.65 µm pore size filters
“Filtration method”
Curved Gram-negative bacilli, Oxidase positive, weak Catalase positive, Urease negative
“Arcobacter spp.”
Causes Peptic Ulcer and Peptic Cancer
“Helicobacter pylori”
Virulence factor of H. pylori that produces exotoxin creating vacuoles and loosens tight junctions
“VacA”
Virulence factor of H. pylori that is part of pathogenicity islands causing peptic carcinoma
“CagA”
Virulence factor of H. pylori that binds Leb antigens in gastric epithelial cells
“BabA”
Virulence factor of H. pylori associated with peptic ulcers
“IceA”
Other Helicobacter species isolated from bacteremic homosexual men with HIV
“H. rappini, H. cinaedi, H. fennelliae”
Tests positive for Catalase, Oxidase, Motility, Urease (Urea Breath Test)
“Helicobacter spp.”
Growth requirements for Helicobacter spp.
“Microaerophilic, Curved Gram-negative bacilli”
Transport media for tissue biopsy of H. pylori
“Brucella broth with glycerol, Stuart’s transport medium, Portagerm pylori media”
Stains used for H. pylori
0.1% basic Fuchsin, Warthin-Starry (silver), Giemsa