Pathogens

Pathogens

Bacteria, Fungi and Viruses, Sizes and Significance
(Sizes in Microns)

Note: Most are above 0.1M in size. None are below 0.01 in size.

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 coll  
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
Opportunistic infections
Pseudormonas diminuta
Bacteria
 
1.0 0.3
 
Test organism for retention 0.2 µm membranes
Rhinorvirus
Virus
 
0.023
Humans
Colds
Rhizopus stolonifer
Fungi
 
8
Environmental
Zygomycosis
Rhodoturula spp.
Fungi
 
14
Environmental
Extrinsic Allergic Aveons
Salmonella enteritidis
Bacteria
2.0-3.0
0.6-0.7
 
Causes food poisoning
Salmonella enteritidis
Bacteria
2.0-3.0
0.6-0.7
 
Causes food poisoning
Salmonella hirschefeldii
Bacteria
1.0-2.5
0.3-0.5
 
Causes enteric fever
Salmonella typhimurium
Bacteria
 
1.0-1.5 0.5
 
Causes food poisoning in man
Salmonella typhosa
Bacteria
2.0-3.0
0.6-0.7
 
Causes typhoid fever
Sarcina maxima
Bacteria
 
4.0-4.5
 
Isolated from fermenting malt mash
Scopulariopsis spp.
Fungi
 
6
Environmental
Onychomycosis
Serratia marcescens
Bacteria
0.5-1.0
0.5
 
Test organism for retention of 0.45 µm membranes
Serratia marcescens
Bacteria
 
1.3
Environmental
Opportunistic infections
Shigella dysenteriae
Bacteria
1.0-3.0
0.4-0.6
 
Causes dysentery in man
Sporothrix schenckii
Fungi
 
6.5
Environmental
Sporotrichosis
Stachybotrys spp.
Fungi
 
5.7
Environmental
Stachybotryotoxicosis
Staphylococcus Aureus
Bacteria
 
0.8-1.0
Humans
Causes pus forming infections, opportunistic infections
Streptoccous lactis
Bacteria
 
0.5-1.0
 
Contaminant in milk
Streptococcus pneumoniae
Bacteria
 
0.9
Humans
Pneumonia, otitis media
Streptococcus pyogenes
Bacteria
 
0.6-1.0 (0.9 average)
Humans
Causes pus forming infections, scarlet fever, pharyngitis
Thermoactinomyces sacchari
Actinomycetes
 
0.86
Agricultural
Bagassosis
Thermoactinomyces vulgaris
Actinomycetes
 
1
Agricultural
Farmers’ lung, Hypersensitivity Pneumonitis
Thermomonspora viridis
Actinomycetes
 
0.6
Agricultural
Farmers’ lung, Hypersensitivity Pneumonitis
Togavirus
Virus
 
0.063
Humans
Rubella (german measles)
Trichoderma spp.
Fungi
 
4.1
Environmental
Mycotoxicosis, Volatile Organic Compound
Ulociadium spp.
Fungi
 
15
Environmental
Extrinsic Allergic Aveons
Varicella-zoster
Virus
 
0.3
Humans
Chickenpox
Wallemia sebi
Fungi
 
3
Environmental
Extrinsic Allergic Aveons
Yersinia pestis
Virus
 
0.75
Humans
Pheumonic plague

Last updated: July 25, 2016