Laboratory Investigations in Microbiology

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Appendix D. Unknown ID images: Gram stains and colonies

Gram-negative bacteria

Aeromonas hydrophila

White/beige single rods 3 - 5 um long

Alcaligenes faecalis

Off-white, spreading edges, turning pink in center single coccobacilli (short rods) 1 - 2 um long

Branhamella catarrhalis

  paired cocci 1 - 2 um in diameter

Chromobacterium violaceum

Small, opaque, purple single rods 2 - 3 um in length

Citrobacter freundii

White/beige single rods 2 - 3 um in length

Edwardsiella tarda

White, flat single rods 2-5 um in length

Enterobacter aerogenes & cloacae

White/beige single rods 2 - 3 um in length

Escherichia coli (B)

White/beige single rods 2 - 3 um in length

Escherichia coli (K12)

White/beige single rods 2 - 3 um in length

Klebsiella pneumoniae

White/beige single rods 2 - 3 um in length

Leclercia adecarboxylata

White/beige/yellow   single rods 2 - 3 um in length

Morganella morganii

White/beige single rods 2 - 3 um in length

Neisseria perflava & sicca

White/beige paired cocci 1 um in diameter

Novosphingobium capsulatum

  Yellow/orang long irregular rods

 

       

Proteus vulgaris

White/beige, swarming single rods 2 - 3 um in length

Providencia alcalifaciens

White/beige single rods 2 - 3 um in length

Pseudomonas aeruginosa

White/beige, spreading edges, turn pink as they get older single rods 2 - 4 um in length

Pseudomonas fluorescens

White/beige single rods 2 - 3 um in length

Pseudomonas putida

Small, pale yellow single rods 2 - 3 um in length

Rhizobium leguminasorum

  Beige/white single rods 2 - 3 um in length

Rhodospirillum rubrum

Small red, grow slowly in young cultures, cells are curved (vibrio) and 2 - 4 um long. As they get older, long spirals (10 - 20 um) may be seen as well

Serratia liquefaciens

White/beige single rods 2 - 3 um in length

Serratia marcesens

Red/orange single rods 2 - 3 um in length

Shigella dysenteriae

White/beige single rods 2 - 3 um in length

Stentrophomonas maltophila

White/beige single rods 2 - 5 um in length

Vibrio natriegens

White/beige single rods 2 - 3 um in length

Vibrio parahaemolyticus

White/beige single rods or curved cells 2 - 3 um in length

Yersinia enterocolitica

White/beige single rods 2 - 3 um in length

Gram-positive bacteria

Arthrobacter globiformis

Opaque white colonies Irregular rods 3 - 5 um

Actinomyces spp.

Small, dry, powdery white colonies Filamentous rods, branching; Spores may be present

Bacillus cereus

Large flat white rod-shaped cells, 3 - 5 um long, in chains; endospores may be visible

Bacillus mycoides

White opaque with rhizoid edges rod-shaped cells, 2 - 4 um long, in chains; endospores may be visible

Bacillus subtilis

large white flat and opaque rod-shaped cells, 3 - 5 um long, in chains; endospores may be visible

Bacillus thuringiensis

  large white flat and opaque rod-shaped cells, 3 - 5 um long, in chains; endospores may be visible

Clostridium sporogenes

white opaque with rhizoid edges single rod-shaped cells; endospores may be present

Corynebacterium pseudodip.

Beige, small and opaque irregular (club-shaped) rods, 2 - 3 um long, often in parallel (palisade) arrangements or V-shapes

Enterococcus faecalis

Small white round or oval cocci, 1 um in diameter, forming pairs or short chains

Kurthia gibsonii

White/Beige opaque regular-shaped rods, 2 - 4 um long, in pairs or short chains

Lactobacillus acidophilus

Small white single rods, 2 - 3 um long

Lactobacillus plantarum

Small white single rods, 2 - 3 um long

Leuconostoc mesenteroides

translucent white colonies chains of cocci 1 um in diameter

Listeria monocytogenes

Small translucent white colonies single rods, 2 - 3 um long

Micrococcus luteus

Small pale yellow cocci 1 - 2 um in diameter, in regular clusters, esp. tetrads

MIcrococcus lysodeitikus

Medium sized beige colonies clusters/tetrads of cocci 1 - 2 um in diameter

Micrococcus nishyominensis

  orange/red cocci 1 - 2 um in diameter, in regular clusters, esp. tetrads

Micrococcus roseus

Small pink cocci 1 - 2 um in diameter, in regular clusters, esp. tetrads

Mycobacterium phlei

Small crumbly/dry white/beige thin rods, 3 - 5 um long, often clumped into filaments

Nocardia corallina

Small white powder colonies branching filaments (hyphae)

Pediococcus damnosus

Small white cocci, often clumped or in tetrads

Paenibacillus polymyxa

  flat white long thin rods, 3 - 5 um; spores and endospores may be present

Sarcina auriantiaca

  orange/red cocci in tetrads

Sporosarcina ureae

Dark yellow, small cocci, 1 um in diamater, clumped into tetrads

Staphylococcus aureus

Yellow/golden cocci, 1 um in diameter, in irregular clusters

Staphylococcus epidermis

White cocci, 1 um in diameter, in irregular clusters

Staphylococcus saprophyticus

White cocci, 1 um in diameter, in irregular clusters

Staphylococcus xerosis

golden yellow cocci, 1-2 um in diameter, in irregular clusters

Streptococcus lactis

Small white cocci (oval or round) in short or long chains

Streptococcus pyogenes

Small white oval or round cocci, 1 um in diameter, often in long chains

Streptococcus thermophilus

  Small white cocci (oval or round) in short or long chains

Streptomyces antibioticus

  Powdery/filamentous white branching filaments