Microorganisms Database

Discover our comprehensive collection of microorganisms

Gram negative bacilli - enterobacteriaceae

Escherichia coli

Morphology

  • Shape: Rod
  • Arrangement: Single or pairs
  • Size: 1-2 μm in length, 0.25-1 μm in diameter
  • Motility: Motile (peritrichous flagella) or non-motile
  • Capsule: Some strains have capsule
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Negative
  • Catalase: Positive
  • Indole: Positive
  • Methyl_red: Positive
  • Vp: Negative
  • Citrate: Negative (most strains)
  • Urease: Negative
  • H2s_production: Negative
  • Tsi: A/A, gas +, H2S -
  • Of_glucose: Fermentative
  • Lactose_fermentation: Positive (most strains)
  • Motility_test: Positive (most strains)

Growth Conditions

  • Temperature_range: 15-45°C
  • Optimal_temp: 37°C
  • Oxygen: Facultative anaerobe
  • Macconkey: Pink colonies (lactose fermenter)
  • Blood_agar: Gray, moist colonies, some strains hemolytic
Klebsiella pneumoniae

Morphology

  • Shape: Rod
  • Arrangement: Single
  • Size: 1-2 μm length, 0.5-0.8 μm diameter
  • Motility: Non-motile
  • Capsule: Thick polysaccharide capsule
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Negative
  • Catalase: Positive
  • Indole: Negative (K. pneumoniae), Positive in some subspecies
  • Methyl_red: Negative
  • Vp: Positive
  • Citrate: Positive
  • Urease: Positive
  • H2s_production: Negative
  • Tsi: A/A, gas +, H2S -
  • Of_glucose: Fermentative
  • Lactose_fermentation: Positive
  • Motility_test: Negative

Growth Conditions

  • Temperature_range: 10-42°C
  • Optimal_temp: 37°C
  • Oxygen: Facultative anaerobe
  • Macconkey: Pink, mucoid colonies
  • Blood_agar: Large, mucoid colonies, non-hemolytic
Salmonella enterica

Morphology

  • Shape: Rod
  • Arrangement: Single
  • Size: 1-3 μm length, 0.5-0.8 μm diameter
  • Motility: Motile (peritrichous flagella)
  • Capsule: Vi antigen in some strains
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Negative
  • Catalase: Positive
  • Indole: Negative
  • Methyl_red: Positive
  • Vp: Negative
  • Citrate: Positive
  • Urease: Negative
  • H2s_production: Positive
  • Tsi: K/A, gas +, H2S +
  • Of_glucose: Fermentative
  • Lactose_fermentation: Negative
  • Motility_test: Positive

Growth Conditions

  • Temperature_range: 15-43°C
  • Optimal_temp: 37°C
  • Oxygen: Facultative anaerobe
  • Macconkey: Pale colonies (non-lactose fermenter)
  • Blood_agar: Smooth, moist colonies, usually non-hemolytic
Proteus mirabilis

Morphology

  • Shape: Rod
  • Arrangement: Single
  • Size: 1-3 μm length, 0.5-0.8 μm diameter
  • Motility: Highly motile (swarming motility)
  • Capsule: Absent
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Negative
  • Catalase: Positive
  • Indole: Negative
  • Methyl_red: Positive
  • Vp: Negative
  • Citrate: Positive
  • Urease: Positive
  • H2s_production: Positive
  • Tsi: K/A, gas +, H2S +
  • Of_glucose: Fermentative
  • Lactose_fermentation: Negative
  • Motility_test: Positive

Growth Conditions

  • Temperature_range: 10-43°C
  • Optimal_temp: 37°C
  • Oxygen: Facultative anaerobe
  • Macconkey: Pale colonies
  • Blood_agar: Swarming growth, strong odor

Gram positive cocci - clusters

Staphylococcus aureus

Morphology

  • Shape: Coccus
  • Arrangement: Clusters
  • Size: 0.5-1 μm in diameter
  • Motility: Non-motile
  • Capsule: Present in some strains
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Negative
  • Catalase: Positive
  • Indole: Negative
  • Methyl_red: Variable
  • Vp: Positive
  • Citrate: Variable
  • Urease: Positive (some strains)
  • H2s_production: Negative
  • Tsi: A/A, gas -, H2S -
  • Of_glucose: Fermentative
  • Lactose_fermentation: Negative
  • Motility_test: Negative

Growth Conditions

  • Temperature_range: 15-45°C
  • Optimal_temp: 37°C
  • Oxygen: Facultative anaerobe
  • Macconkey: No growth
  • Blood_agar: Golden-yellow, beta-hemolytic colonies

Gram negative bacilli - non-fermenter

Pseudomonas aeruginosa

Morphology

  • Shape: Rod
  • Arrangement: Single
  • Size: 1.5-3 μm in length, 0.5-1 μm in diameter
  • Motility: Motile (polar flagella)
  • Capsule: Slime layer in some strains
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Positive
  • Catalase: Positive
  • Indole: Negative
  • Methyl_red: Negative
  • Vp: Negative
  • Citrate: Positive
  • Urease: Negative
  • H2s_production: Negative
  • Tsi: K/K, gas -, H2S -
  • Of_glucose: Oxidative
  • Lactose_fermentation: Negative
  • Motility_test: Positive

Growth Conditions

  • Temperature_range: 25-42°C
  • Optimal_temp: 37°C
  • Oxygen: Obligate aerobe (can use nitrate anaerobically)
  • Macconkey: Pale colonies (non-lactose fermenter)
  • Blood_agar: Large, flat colonies with metallic sheen, beta-hemolytic

Gram positive cocci - chains

Enterococcus faecalis

Morphology

  • Shape: Coccus
  • Arrangement: Pairs and short chains
  • Size: 0.6-2.0 μm diameter
  • Motility: Non-motile
  • Capsule: Absent
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Negative
  • Catalase: Negative (weak reaction possible)
  • Indole: Negative
  • Methyl_red: Positive
  • Vp: Variable
  • Citrate: Variable
  • Urease: Negative
  • H2s_production: Negative
  • Tsi: A/A, gas -, H2S -
  • Of_glucose: Fermentative
  • Lactose_fermentation: Positive
  • Motility_test: Negative

Growth Conditions

  • Temperature_range: 10-45°C
  • Optimal_temp: 37°C
  • Oxygen: Facultative anaerobe
  • Macconkey: Poor or no growth
  • Blood_agar: Small, translucent colonies, gamma or alpha hemolysis

Gram positive bacilli - non-spore forming

Listeria monocytogenes

Morphology

  • Shape: Rod
  • Arrangement: Single or short chains
  • Size: 0.5-2 μm length, 0.5 μm diameter
  • Motility: Tumbling motility at room temp
  • Capsule: Absent
  • Spores: Non-spore forming

Biochemical Characteristics

  • Oxidase: Negative
  • Catalase: Positive
  • Indole: Negative
  • Methyl_red: Variable
  • Vp: Positive
  • Citrate: Negative
  • Urease: Negative
  • H2s_production: Negative
  • Tsi: A/A, gas -, H2S -
  • Of_glucose: Fermentative
  • Lactose_fermentation: Negative
  • Motility_test: Positive at 25°C

Growth Conditions

  • Temperature_range: 0-45°C
  • Optimal_temp: 30-37°C
  • Oxygen: Facultative anaerobe
  • Macconkey: No growth
  • Blood_agar: Small colonies, narrow beta hemolysis

Bacteria - gram positive cocci

Streptococcus pyogenes

Biochemical Characteristics

  • Catalase: Negative
  • Hemolysis: Beta
  • Bacitracin_sensitivity: Sensitive
  • Pyr: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Causes strep throat, scarlet fever, rheumatic fever
Streptococcus pneumoniae

Biochemical Characteristics

  • Catalase: Negative
  • Optochin_sensitivity: Sensitive
  • Bile_solubility: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Capsule: Polysaccharide capsule
  • Pathogenicity: Causes pneumonia, meningitis, otitis media
Streptococcus agalactiae

Biochemical Characteristics

  • Catalase: Negative
  • Hemolysis: Beta
  • Camp_test: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Neonatal sepsis, meningitis
Streptococcus mutans

Biochemical Characteristics

  • Catalase: Negative
  • Lactose_fermentation: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Dental caries

Bacteria - gram negative cocci

Neisseria gonorrhoeae

Biochemical Characteristics

  • Oxidase: Positive
  • Glucose_utilization: Positive
  • Maltose_utilization: Negative

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Gonorrhea, neonatal conjunctivitis
Neisseria meningitidis

Biochemical Characteristics

  • Oxidase: Positive
  • Glucose_utilization: Positive
  • Maltose_utilization: Positive

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Capsule: Polysaccharide capsule
  • Pathogenicity: Meningitis, septicemia

Bacteria - gram negative rods

Shigella dysenteriae

Biochemical Characteristics

  • Oxidase: Negative
  • Lactose_fermentation: Negative
  • H2s_production: Negative
  • Urease: Negative

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Bacillary dysentery
Salmonella Typhi

Biochemical Characteristics

  • Oxidase: Negative
  • Lactose_fermentation: Negative
  • H2s_production: Positive
  • Urease: Negative

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Typhoid fever
Legionella pneumophila

Biochemical Characteristics

  • Oxidase: Positive
  • Growth_requirement: Cysteine and iron

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Legionnaires' disease
Yersinia pestis

Biochemical Characteristics

  • Oxidase: Negative
  • Urease: Negative

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Plague
Enterobacter cloacae

Biochemical Characteristics

  • Oxidase: Negative
  • Lactose_fermentation: Positive
  • Urease: Variable

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Hospital-acquired infections, UTIs
Escherichia coli O157:H7

Biochemical Characteristics

  • Oxidase: Negative
  • Lactose_fermentation: Positive
  • Sorbitol_fermentation: Negative

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Hemorrhagic colitis, hemolytic uremic syndrome
Shigella sonnei

Biochemical Characteristics

  • Oxidase: Negative
  • Lactose_fermentation: Negative
  • Urease: Negative

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Shigellosis

Bacteria - gram negative curved rods

Vibrio cholerae

Biochemical Characteristics

  • Oxidase: Positive
  • Glucose_fermentation: Positive
  • Lactose_fermentation: Negative

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Motility: Single polar flagellum
  • Pathogenicity: Cholera
Campylobacter jejuni

Biochemical Characteristics

  • Oxidase: Positive
  • Catalase: Positive
  • Hippurate_hydrolysis: Positive

Other Characteristics

  • Oxygen_requirement: Microaerophilic
  • Pathogenicity: Gastroenteritis, Guillain-Barré syndrome
Vibrio parahaemolyticus

Biochemical Characteristics

  • Oxidase: Positive
  • Halophilic: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Gastroenteritis from seafood

Bacteria - gram negative coccobacilli

Haemophilus influenzae

Biochemical Characteristics

  • Oxidase: Positive
  • X_and_v_factor_requirement: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Capsule: Polysaccharide capsule in type b
  • Pathogenicity: Meningitis, epiglottitis
Acinetobacter baumannii

Biochemical Characteristics

  • Oxidase: Negative
  • Glucose_oxidation: Positive

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Nosocomial infections, ventilator-associated pneumonia
Brucella melitensis

Biochemical Characteristics

  • Oxidase: Positive
  • Urease: Positive

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Brucellosis

Bacteria - spirochetes

Treponema pallidum

Biochemical Characteristics

  • Motility: Corkscrew motility

Other Characteristics

  • Oxygen_requirement: Microaerophilic
  • Pathogenicity: Syphilis
Borrelia burgdorferi

Biochemical Characteristics

  • Motility: Corkscrew motility

Other Characteristics

  • Oxygen_requirement: Microaerophilic
  • Pathogenicity: Lyme disease
Leptospira interrogans

Biochemical Characteristics

  • Motility: Corkscrew motility

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Leptospirosis

Fungi - yeast

Candida albicans

Biochemical Characteristics

  • Germ_tube_test: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Oral thrush, vaginal candidiasis
Cryptococcus neoformans

Biochemical Characteristics

  • Urease: Positive

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Meningitis in immunocompromised hosts
Candida glabrata

Biochemical Characteristics

  • Germ_tube_test: Negative

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Urinary tract infections, bloodstream infections

Fungi - mold

Aspergillus fumigatus

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Aspergillosis, allergic bronchopulmonary aspergillosis

Fungi - dimorphic

Histoplasma capsulatum

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Histoplasmosis

Bacteria

Bacillus cereus
Mycoplasma pneumoniae
Rickettsia rickettsii
Francisella tularensis
Bordetella pertussis
Helicobacter pylori
Clostridium difficile

Bacteria - acid-fast bacilli

Mycobacterium tuberculosis

Biochemical Characteristics

  • Niacin_test: Positive
  • Nitrate_reduction: Positive

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Tuberculosis

Bacteria - gram positive bacilli

Bacillus cereus

Biochemical Characteristics

  • Catalase: Positive
  • Spore_formation: Positive
  • Lecithinase: Positive

Other Characteristics

  • Oxygen_requirement: Facultative anaerobe
  • Pathogenicity: Food poisoning, endophthalmitis
Corynebacterium diphtheriae

Biochemical Characteristics

  • Catalase: Positive
  • Urease: Negative
  • Toxin_production: Positive (diphtheria toxin)

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Diphtheria
Clostridium perfringens

Biochemical Characteristics

  • Catalase: Negative
  • Spore_formation: Positive
  • Lecithinase: Positive

Other Characteristics

  • Oxygen_requirement: Obligate anaerobe
  • Pathogenicity: Gas gangrene, food poisoning
Propionibacterium acnes

Biochemical Characteristics

  • Catalase: Positive
  • Indole: Variable

Other Characteristics

  • Oxygen_requirement: Anaerobe
  • Pathogenicity: Acne, opportunistic infections

Bacteria - intracellular

Chlamydia trachomatis

Biochemical Characteristics

  • Giemsa_stain: Positive

Other Characteristics

  • Oxygen_requirement: Obligate intracellular
  • Pathogenicity: Chlamydia, trachoma, lymphogranuloma venereum

Bacteria - no cell wall

Mycoplasma pneumoniae

Biochemical Characteristics

  • Glucose_fermentation: Positive

Other Characteristics

  • Oxygen_requirement: Aerobe
  • Pathogenicity: Atypical pneumonia