Consultation outcome

UK SMI ID 1: Appendices text description

Updated 24 September 2021

This page provides an accessible text description of the appendices from the UK Standards for Microbiology Investigations document ‘UK SMI ID 1: introduction to the preliminary identification of medically important bacteria and fungi from culture’. For the full document, view and download ID 1: introduction to the preliminary identification of medically important bacteria and fungi from culture. For the full draft document, see the consultation page.

Appendix 1: characteristics of Gram-positive cocci

Gram-positive cocci

Anaerobic growth only

Peptostreptococcus Gemella morbillorum

Aerobic or facultative growth

Catalase negative:

• Streptococcus^{[footnote 1]}
• Enterococcus
• Abiotrophia
• Aerococcus^{[footnote 2]}
• Gemella
• Helcococcus
• Leuconostoc
• Pediococcus
• Rothia^{[footnote 3]}

Catalase positive:

• Staphylococcus
• Micrococcus
• Rothia^{[footnote 3]}

Appendix 2: characteristics of Gram-positive rods

Gram-positive rods

Anaerobic growth only

Short medium length may be in chains:

• Clostridium (spores)

Coryneform:

• Propionibacterium^{[footnote 4]}
• Actinomyces^{[footnote 4]}
• Bifidobacterium
• Eubacterium

Aerobic or facultative growth:

Branching filaments or beaded:

• Nocardia^{[footnote 4]}
• Streptomyces^{[footnote 4]}
• Actinomyces^{[footnote 4]}
• Mycobacterium^{[footnote 5]}
• Gordona
• Tsukamurella
• Actinomadura

Coccobacilli:

• Corynebacterium
• Listeria
• Erysipelothrix
• Mycobacterium^{[footnote 5]}
• Nocardia
• Rhodococcus

Coryneform:

• Arcanobacterium
• Corynebacterium
• Gardnerella^{[footnote 6]}
• Kurthia^{[footnote 4]}
• Oerskovia
• Propionibacterium^{[footnote 4]}
• Rothia^{[footnote 4]}
• Turicella^{[footnote 4]}
• Brevibacterium
• Cellulomonas
• Dermabacter
• Microbacterium

Large rods, straight sides, may have spores:

• Bacillus (spores) ^{[footnote 5]}
• Lactobacillus (non sporing)

Appendix 3: characteristics of Gram-negative bacteria

Gram-negative bacteria

Cocci / coccobacilli:

Aerobic or facultative:

• Acinetobacter
• Kingella
• Moraxella
• Neisseria

Anaerobic growth only:

• Veillonella

Rods

Aerobic or facultative:

• Refer to Appendix 4

Anaerobic growth only:

• Bacteroides
• Fusobacterium
• Mobiluncus
• Porphyromonas
• Prevotella

Appendix 4: characteristics of Gram-negative bacteria (continued from Appendix 3)

Aerobic or facultative Gram-negative rods

Small and, or, pleomorphic:

• Aggregatibacter^{[footnote 1]}
• Bordetella^{[footnote 1]}
• Brucella^{[footnote 1] [footnote 7]}
• Cardiobacterium^{[footnote 1]}
• Eikenella^{[footnote 1]}
• Francisella^{[footnote 1]}
• Pasteurella^{[footnote 1]}
• Haemophilus^{[footnote 1]}
• Bartonella
• Streptobacillus^{[footnote 1]}
• Acinetobacter

Variable length:

• Legionella^{[footnote 1]} (specific growth requirements)

Straight sided oxidase negative:

• Enterobacteriaceae^{[footnote 2] [footnote 7]}
• Stenotrophomonas^{[footnote 2]}
• Capnocytophaga^{[footnote 8]}
• Acinetobacter
• consider Gardnerella

Straight sided oxidase positive:

• Pseudomonas
• Alcaligenes
• Burkholderia
• Aeromonas
• Flavobacterium
• Capnocytophaga
• Acidovorax
• Chromobacterium
• Comamonas
• Kingella^{[footnote 1]}

Curved:

• Vibrio
• Campylobacter (microaerobic)
• Arcobacter (microaerobic)
• Helicobacter (microaerobic)

Appendix 5: characteristics of fungi

Moulds (filamentous)

Aseptate hyphae

Mucoraceous moulds (formerly Zygomycetes):

• Mucor species
• Rhizopus species
• Basidiobolus species
• Conidiobolus species
• Lichtheimia (previously Absidia) species
• Rhizomucor species

Septate hyphae

Monomorphic:

• Fusarium species
• Aspergillus species
• Microsporum species
• Trichophyton species
• Phialophora species
• Epidermophtyon floccosum
• Cladosporium species
• Madurella species
• Acremonium species
• Scedosporium species

Dimorphic:

• Histoplasma species^{[footnote 9]}
• Blastomyces dermatitidis^{[footnote 9]}
• Paracoccidiodes brasiliensis^{[footnote 9]}
• Coccidioides immitis^{[footnote 9]}
• Talaromyces (previously Penicillium) marneffei^{[footnote 9]}
• Sporothrix schenckii

Yeasts (unicellular) ^{[footnote 10]}

Germ-tube positive

• Candida albicans
• Candida dubliniensis
• Candida africana

Pseudohyphae or budding yeast:

• Candida species
• Cryptococcus species
• Saccharomyces species

Arthrospores:

• Trichosporon species
• Saprochaete capitate

Pink or red colonies:

• Rhodotorula species
• Sporobolomyces species

Minute colonies

Presumptive Malassezia species.

1. Some species may be anaerobic. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹²

2. May be weak catalase positive. ↩ ↩² ↩³

3. This organism is pleomorphic (with a variation in the size and shape of cells) catalase variable, catalase test may not be helpful for differentiation. ↩ ↩²

4. This organism is pleomorphic. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

5. These organisms (that is, Mycobacterium tuberculosis and Bacillus anthracis) are hazard group 3 organisms and should be processed in a Containment level 3 laboratory. Mycobacterium species should be referred to the Reference Laboratory for full identification. ↩ ↩² ↩³

6. Gardnerella vaginalis is a Gram variable rod and may usually be differentiated by its microscopic appearance. ↩

7. These organisms (that is, Brucella species and species within the family Enterobacteriaceae) are hazard group 3 organisms and should be processed in Containment level 3 laboratories. ↩ ↩²

8. This organism is pleomorphic, catalase variable and a facultative anaerobe. ↩

9. These fungi are hazard group 3 organisms and should be processed in a Containment level 3 laboratory. ↩ ↩² ↩³ ↩⁴ ↩⁵

10. C. glabrata does not form pseudohyphae or a germ tube. ↩