What is the typical appearance of Enterobacteriaceae under a microscope?

What is the typical appearance of Enterobacteriaceae under a microscope?

• A. Spiral-shaped
• B. Rod-shaped
• C. Clustered cocci
• D. Square-shaped

Answer: (B)

Enterobacteriaceae are a group of bacteria that are characteristically rod-shaped. Under the microscope they appear as straight or slightly curved rods (bacilli), usually seen alone or in short chains, rather than as spirals or as clusters of round cells. This rod shape is a hallmark that helps distinguish them from other bacteria: spiral-shaped organisms (like certain curved pathogens) and cocci in clusters (like Staphylococcus) have clearly different appearances. There aren’t square-shaped bacteria in this family, so that option isn’t representative of their typical look.

Enterobacteriaceae are a group of bacteria that are characteristically rod-shaped. Under the microscope they appear as straight or slightly curved rods (bacilli), usually seen alone or in short chains, rather than as spirals or as clusters of round cells. This rod shape is a hallmark that helps distinguish them from other bacteria: spiral-shaped organisms (like certain curved pathogens) and cocci in clusters (like Staphylococcus) have clearly different appearances. There aren’t square-shaped bacteria in this family, so that option isn’t representative of their typical look.