Table 1.

Microbiological analysis of samples

Colony size	Lactose fermenter	Color of colony	Gram staining	Other tests	Inference
1–2 mm	Yes	Magenta	Gram-positive cocci in pairs	• Bile Esculin agarpositive	• Enterococci
				• Heat tolerant at 60°C for 30 minutes
				• Bile Esculin agar positive	• Non-enterococcal group IV streptococci
				• Heat sensitive at 60°C for 30 minutes
1–3 mm	Yes	Pink	Gram-positive bacilli in palisades	No additional tests performed	• Diphtheroids
1–2 mm	Yes	Salmon pink	Gram-positive cocci in clusters	• Coagulase-negative	• Coagulase-negative staphylococci
				• Coagulase positive	• Staphylococcus aureus
2–5 mm	No	Pale	Gram-negative coccobacilli	• Non-fermenter on glucose fermentation media	• Acinetobacter species
				• Oxidase negative
				• Non-motile
3–6 mm	Yes	Pink, mucoid	Gram-negative bacilli	• Fermenter on glucose media	• Klebsiella pneumoniae
				• Citrate utilizationpositive
0.5–1 mm	Yes	Pink	Budding cells seen	No additional tests performed	• Candida species
1–4 mm	Variable	Pink	Spore-containing bacilli	No additional tests performed	• Aerobic spore bearers (usually contaminants)