Organism

Microbial Group

Rod Length µm

Rod or Coccus Diameter µm

Source

Significance

Absidia corymbifera

Fungi

3.8

Environmental

Zygomycosis

Acetobacter Melanogenus

Bacteria

1.0-2.0

0.4-0.8

Strong beer/vinegar bacterium.

Acinetobacter

Bacteria

1.3

Environmental

Opportunistic infections

Acremonium spp.

Fungi

2.5

Environmental

Extrinsic Allergic Aveons

Actinomyces israelii

Bacteria

1.0

Humans

Antinomycosis

Adenovirus

Virus

0.08

Humans

Colds

Alcaligenes Viscolactis

Bacteria

0.8-2.6

0.6-1.0

Causes ropiness in milk.

Alkaligenes

Bacteria                

0.75

Humans

Opportunistic infections

Alternaria alternata

Fungi

14.4

Environmental

Mycotoxicosis

Arenavirus

Virus

0.18

Rodents

Hemorrhagic fever

Aspergillis spp.

Fungi

3.5

Environmental

Aspergillosis, Volatile Organic Compound

Aureobasidium pullulans

Fungi

5

Environmental

Chromomycosis

Bacillus anthracis

Bacteria

3.0-10.0

1.0-1.3

(1.1 average)

Environmental

Causes anthrax in mammals

Bacillus Stearothermophilus

Bacteria

2.0-5.0

0.6-1.0

Biological indicator for steam sterilization

Bacillus subtilis

Bacteria

2.0-3.0

0.7-0.8

Biological indicator for ethylene oxide sterilization

Blastomyces dermatiitidis

Fungi

14

Environmental

Blastomycosis

Bordetella pertussis

Bacteria

0.25

Humans

Whooping cough

Botrytis cinera

Fungi

7

Environmental

Extrinsic Allergic Aveons

Cardiobacterium

Bacteria                

0.63

Humans

Opportunistic infections

Chaetomium globosum

Fungi

5.5

Environmental

Chromomycosis, Volatile Organic Compound

Chiamydia psittaci

Bacteria

0.3

Birds

Psittacosis

Chlamydia pneumoiae

Virus

0.3

Humans

Pneumonia

Cladosporium spp.

Fungi

9

Environmental

Chromblastomycosis

Clostridium botulinum (B)

Bacteria                

3.0-8.0

0.5-0.8

Produces exotin causes botulism

Clostridium Perinngens

Bacteria

4.0-8.0

1.0-1.5

Produces toxin causing food poisoning

Clostridium tetani

Bacteria                

4.0-8.0

0.4-0.6

Produces exotoxin causing tetanus

Coccidioides immitis

Fungi     

4

Environmental

Coccidiodomycosis

Coronavirus

Virus

0.11

Humans

Colds

Corynebacteria diphtheria

Bacteria                

1.0

Humans

Diphtheria

Coxiella burnetii

Bacteria

0.5

Cattle, sheep

Q fever

Coxsackievirus

Virus

0.027

Humans

Colds

Cryptococcus neoformans

Fungi

5.5

Environmental

Cryptococcosis

Diplococcus Pneumoniae

Bacteria                

0.5-1.25

Causes lobar pneumonia

Echovirus

Virus

0.028

Humans

Colds

Emericella nidulans

Fungi

3.3

Environmental

Mycotoxicosis, Volatile Organic Compound

Epicoccum nigrum

Fungi

20

Environmental

Extrinsic Allergic Aveons

Erwina aroideae

Bacteria                

2.0-3.0

0.5

Causes soft rot in vegetables.

Escherichia Coli
(E Coli) 

Bacteria                

1.0-3.0

0.5

Indicator of fecal contamination in water.

Eurotium spp.

Fungi

5.8

Environmental

Extrinsic Allergic Aveons

Exophiala jeanselmei

Fungi

2

Environmental

Chromomycosis

Francisella tularensis

Bacteria                

0.2

Wild animals

Tularemia

Geomyces pannorum

Fungi

3

Environmental

Extrinsic Allergic Aveons

Haemophilus influenzae

Bacteria                

0.5-2.0

0.2-0.3

Causes influenza and acute respiratory infections

Haemophilus influenzae

Bacteria                

0.43

Humans

Meningitis, pneumonia

Haemophilus parainfluenzae

Bacteria

1

Humans

Opportunistic infections

Hantavirus

Virus

0.07

Rodents

Hantavirus

Helminthosporium

Fungi     

12.5

Environmental

Extrinsic Allergic Aveons

Histoplasma capsulatum

Fungi

3

Environmental

Histoplasmosis

Influenza

Virus

0.1

Humans, birds

Flu

Klebsielia pneumoniae

Bacteria                

5

0.4-0.5

Environmental

Opportunistic infections, causes pneumonia and other respiratory inflammation

Lactobacillus Delbrueckil

Bacteria                

2.0-9.0

0.5-0.8

Causes souring of grain-mashes

Legionella pneumophia

Bacteria                

0.6

Environmental

Pontiac fever

Micromonospora faeni

Actinomycetes

1

Agricultural

Farmers' lung, Hypersensitivity Pneumonitis

Micropolyspora faeni

Actinomycetes

0.69

Agricultural

Farmers' lung, Hypersensitivity Pneumonitis

Moraxella catarrhalis

Bacteria                

1.3

Humans

Opportunistic infections

Moraxella lacunata

Bacteria

1

Humans

Opportunistic infections

Morbillvirus

Virus

0.12

Humans

Measles (rubeola)

Mucor plumbeus

Fungi

7.5

Environmental

Mucormycosis

Mycobacterium avium

Bacteria

1.2

Environmental

Cavitary pulmonary disorder

Mycobacterium intracellulare

Bacteria                

1.2

Environmental

Cavitary pulmonary disorder

Mycobacterium kansasli

Bacteria                

0.86

Unknown

Cavitary pulmonary disorder

Mycobacterium Tuberculosis

Bacteria                

1.0-4.0

0.2-0.5

(0.86 average)

Humans

Hard swelling of body tissues. TB

Mycoplasma pneumoniae

Bacteria                

0.25

Humans

Pneumonia

Mycoplasma pneumoniae (PPLO)

Bacteria

0.3-0.5

Smallest known free-living organism

Neisseria meningitidis

Bacteria                

0.8

Humans

Meningitis

Nocardia Brasilensis

Actinomycetes

1.5

Environmental

Pulmonary mycetoma

Nocardiaasteroides

Actinomycetes

1.1

Environmental

Nocardiosis

Paecilomyces variotii

Fungi     

3

Environmental

Mucormycosis

Paracoccidioides brasilensis

Fungi

23

Environmental

Paracoccidioidomycosis

Parainfluenza

Virus      

0.22

Humans

Flu

Paramyxovirus

Virus

0.23

Humans

Mumps

Parvovirus B19

Virus

0.022

Humans

Filth disease, anemia

Pediococcus acidilactci

Bacteria                

0.6-1.0

Causes mash spoilage in brewing

Pediococcus Cerevisiae

Bacteria                

1.0-1.3

Causes deterioration in beer

Penicillium spp.

Fungi

3.3

Environmental

Mycotoxicosis, Volatile Organic Compound

Phialophora spp.                

Fungi

1.5

Environmental

Chromomycosis

Phoma spp

Fungi

3.3

Environmental

Mucormycosis

Pneumocystis carinii

Bacteria                

2

Environmental

Pneumocystosis

Poxvirus - Vaccinia

Virus

0.23

Agricultural

Cowpox

Pseudomonas aeruginosa

Bacteria

0.57

Environmental

Opportunistic infections

Pseudomonas mallei

Bacteria

0.77

Environmental

Opportunistic infections

Pseudomonas pseudomallei

Bacteria                

0.57

Environmental