4 Common Enterobacteriaceae (and a key non-fermenter) on MacConkey Agar 🧫 MacConkey agar helps differentiate Gram-negative bacteria based on lactose fermentation and colony morphology: 🟣 Escherichia coli • Strong lactose fermenter • Bright pink to red colonies • Often with bile precipitate 🟣 Klebsiella pneumoniae • Lactose fermenter • Large, mucoid, pink colonies • Thick capsule gives a glossy appearance ⚪ Proteus mirabilis • Non-lactose fermenter • Pale, colorless colonies • Swarming inhibit

6.3K views · 123 reactions | E. coli on MacConkey agar producing pink colonies with precipitated bile. #Elmicrobiologist #Clinical #Medical #Microbiology #Ecoli #ESBL #CRE #bacteriology #bacteria | Elmicrobiologist | Facebook