Gram Negative Bacteria Exam 3

Neisseria gonorrhoeae

• Gram Reaction: Negative

• Cell Shape: Cocci

• Oxygen Requirement: Aerobic

• Transmission: STI, autoinoculation

• Key Assays: Oxidase +, Glucose +, Maltose -

• Virulence Determinants: Pili, IgA protease, LOS endotoxin

• Diseases: Gonorrhea, PID, DGI, Conjunctivitis

Neisseria meningitidis

• Gram Reaction: Negative

• Cell Shape: Diplococci

• Oxygen Requirement: Aerobic

• Transmission: Respiratory droplets

• Key Assays: Oxidase +, Glucose +, Maltose +

• Virulence Determinants: Capsule, LOS endotoxin, IgA protease

• Diseases: Meningitis, Meningococcemia (DIC)

Escherichia coli

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Facultative anaerobe

• Transmission: Fecal-oral, autoinoculation

• Key Assays: Lactose +, Indole +, Oxidase -

• Virulence Determinants: P pili (UTI), K1 capsule (meningitis), Shiga-like toxin (HUS)

• Diseases: UTI, HUS, Meningitis, Sepsis, Gastroenteritis

Klebsiella pneumoniae

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Facultative anaerobe

• Transmission: Fecal-oral, soil, nosocomial

• Key Assays: Lactose +, Urease +, Oxidase -

• Virulence Determinants: Polysaccharide capsule (mucoid colonies), LPS endotoxin

• Diseases: UTI, Pneumonia, Meningitis, Sepsis

Shigella dysenteriae

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Facultative anaerobe

• Transmission: Fecal-oral

• Key Assays: H₂S -, Lactose -, Oxidase -

• Virulence Determinants: Shiga toxin, Type III secretion system

• Diseases: Dysentery

Salmonella

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Facultative anaerobe

• Transmission: Zoonosis, fecal-oral, cross-placental

• Key Assays: H₂S +, Lactose -, Motile, Oxidase -

• Virulence Determinants: Vi capsule, Type III secretion system

• Diseases: Gastroenteritis, Septicemia, Typhoid fever

Yersinia pestis

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Facultative anaerobe

• Transmission: Flea bites, respiratory droplets

• Key Assays: Lactose -, Oxidase -

• Virulence Determinants: F1 capsule, Yops proteins, Plasminogen activator

• Diseases: Bubonic plague, Pneumonic plague, DIC

Pseudomonas aeruginosa

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Aerobic

• Transmission: Environmental, nosocomial

• Key Assays: Oxidase +, Pigments (Pyocyanin, Pyoverdine), Glucose -

• Virulence Determinants: Exotoxin A, Biofilm (Alginate), Elastase

• Diseases: Opportunistic infections (CF pneumonia, burns, UTIs)

Haemophilus influenzae

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Facultative anaerobe

• Transmission: Respiratory droplets

• Key Assays: Requires X (iron) and V (NAD) factors, Capsule

• Virulence Determinants: Polysaccharide capsule, IgA protease

• Diseases: Meningitis, Epiglottitis, Conjunctivitis, Otitis/Sinusitis, Pneumonia

Vibrio cholerae

• Gram Reaction: Negative

• Cell Shape: Spiral

• Oxygen Requirement: Facultative anaerobe

• Transmission: Fecal-oral

• Key Assays: Oxidase +, Alkaline growth, Sucrose +

• Virulence Determinants: Cholera toxin (enterotoxin)

• Diseases: Cholera

Treponema pallidum

• Gram Reaction: Negative

• Cell Shape: Spirochete

• Oxygen Requirement: Obligate anaerobe

• Transmission: STI

• Key Assays: Darkfield microscopy, Serology (VDRL, RPR)

• Virulence Determinants: Outer membrane proteins, Hyaluronidase

• Diseases: Syphilis (Primary, Secondary, Tertiary)

Borrelia burgdorferi

• Gram Reaction: Negative

• Cell Shape: Spirochete

• Oxygen Requirement: Microaerophilic

• Transmission: Tick-borne

• Key Assays: ELISA, Western Blot

• Virulence Determinants: Linear chromosomes, Osp proteins

• Diseases: Lyme disease

Chlamydia trachomatis

• Gram Reaction: Negative (No PG)

• Cell Shape: Rod

• Oxygen Requirement: Obligate intracellular

• Transmission: STI, autoinoculation

• Key Assays: NAAT (PCR), Inclusion bodies

• Virulence Determinants: Elementary/Reticulate body life cycle

• Diseases: Nongonococcal Urethritis, LGV, Keratoconjunctivitis

Rickettsia rickettsii

• Gram Reaction: Negative

• Cell Shape: Rod

• Oxygen Requirement: Obligate intracellular

• Transmission: Tick-borne (transovarian transmission)

• Key Assays: Weil-Felix test, Serology

• Virulence Determinants: Actin polymerization, Endothelial cell invasion

• Diseases: Rocky Mountain Spotted Fever

Aeromonas hydrophila

• Gram Reaction: Gram-negative (GNR)

• Cell Shape: Rod

• Oxygen Requirement: Facultative anaerobe

• Transmission: Waterborne

• Key Assay(s): Oxidase +

• Virulence Factors: Enterotoxin

• Diseases: Gastroenteritis

Legionella pneumophila

• Gram Reaction: Gram-negative (GNR)

• Cell Shape: Rod

• Oxygen Requirement: Aerobic

• Transmission: Water, environmental

• Key Assay(s): Oxidase +

• Virulence Factors: Intracellular parasite

• Diseases: Legionnaires' disease

Bordetella pertussis

• Gram Reaction: Gram-negative (GNR)

• Cell Shape: Rod

• Oxygen Requirement: Aerobic

• Transmission: Respiratory

• Key Assay(s): Oxidase +

• Virulence Factors: Pertussis toxin

• Diseases: Whooping cough

Francisella tularensis

• Gram Reaction: Gram-negative (GNR)

• Cell Shape: Rod

• Oxygen Requirement: Aerobic

• Transmission: Tick-borne

• Key Assay(s): Oxidase -

• Virulence Factors: Lipid capsule

• Diseases: Tularemia

Campylobacter

• Gram Reaction: Gram-negative (GNS)

• Cell Shape: Spiral

• Oxygen Requirement: Microaerophilic

• Transmission: Foodborne

• Key Assay(s): Thermotolerant

• Virulence Factors: Flagella, Enterotoxins

• Diseases: Gastroenteritis

Rickettsia prowazekii

• Gram Reaction: Gram-negative (intracellular)

• Cell Shape: rod

• Oxygen Requirement: Obligate intracellular

• Transmission: Body lice

• Key Assay(s): Weil-Felix test

• Virulence Factors: Actin polymerization

• Diseases: Epidemic typhus

Mycoplasma pneumoniae

• Gram Reaction: -

• Cell Shape: none

• Oxygen Requirement: Aerobic

• Transmission: Respiratory droplets

• Key Assay(s): Cold agglutinin test

• Virulence Factors: Adhesins, membrane disruption

• Diseases: Atypical pneumonia

Ehrlichia chaffeensis

• Gram Reaction: Gram-negative (intracellular)

• Cell Shape: rod

• Oxygen Requirement: Obligate intracellular

• Transmission: Tick-borne

• Key Assay(s): PCR, Serology

• Virulence Factors: Intracellular survival

• Diseases: Ehrlichiosis

Chlamydia pneumoniae

• Gram Reaction: Gram-negative (intracellular)

• Cell Shape: rod

• Oxygen Requirement: Obligate intracellular

• Transmission: Respiratory droplets

• Key Assay(s): NAAT, Serology

• Virulence Factors: Intracellular replication

• Diseases:, Bronchitis, Pneumonia

Helicobacter pylori

• Gram Reaction: Gram-negative (GNS)

• Cell Shape: Spiral

• Oxygen Requirement: Microaerophilic

• Transmission: Autoinoculation

• Key Assay(s): Urease +

• Virulence Factors: Flagella

• Diseases: Ulcers, Gastric cancer

Chlamydia

GNR, no PG, OIP

Unique life cycle

–Elementary Body

–Reticulate Body

GN, wall less bacteria

L-forms – induced wall-less phenotype

–Spheroplasts

–Protoplasts

Spirochetes

GNS, Axial filaments = intracellular flagella

–protoplasmic cylinder

–outer sheath

Treponema pallidum

Borrelia burgdorferi

What bacteria has a oxygen requirement MA?

Helicobacter

Borrelia Burgdorferi

Campylobacter

How do you tell the difference between Escherichia E.coli and Klebsiella

Motility

Klebsiella is nonmotile

Escherichia E.coli is motile

Flu-like, blood culture, FA, GNR, Does not ferment lactose

Salmonella (motile) or Yersinia (nonmotile)

Motility Differs

What Causes pneumonia and requires growth factors?

Haemophilus Influenza

Legionella pneumophia

Sepsis (1GP, 2 GN)

Strep Pneumoniae (Positive),(Coccus),(FA)

Treponema Pallidum (Negative), (Spiral), (OA)

Borrella Burdoferi ( Negative), (Spiral),(MA)

Conjunctivitis with pustular discharge (3 GN)

Neisseria Gonnorea (negative),(cocci),(A)

Chlamydia Trachnomatis (negative), (Rod),(OIP)

Haemophilus Influenza (negative), (Rod), (A)

Gastroenteritis via food infection (1 GP, 2 GN)

Bacillus cerus (FA), (Positive), (Rod)

Salmonella (negative), (Rod), (FA)

Camplyobacter (negative), (spiral), (MA)

Pneumonia (1 GP, 2 GN)

Staph Aureus (Positive) (FA) (Coccus)

Chlamydia Pneumonia (Negaitive) (OIP) (Rod)

Klebsiella Pneumonia (Negative) (FA) (Rod)