Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the
Staphylococcus bacteria
Coxiella burnetii (TEM)
Campylobacter jejuni is a common pathogen of bacterial food-related gastrointestinal illness.
Thin spirochete Treponema pallidum bacteria, the causative agent of syphilis magnified 400 times.
Gram stain
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Gram stain is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. It may also be used to diagnose a fungal infection. The
A Gram stain of mixed Staphylococcus aureus (S. aureus ATCC 25923, gram-positive cocci, in purple) and Escherichia coli (E. coli ATCC 11775, gram-negative bacilli, in red), the most common Gram stain reference bacteria
Gram stain of Candida albicans from a vaginal swab. The small oval chlamydospores are 2–4 μm in diameter.
Purple-stained gram-positive (left) and pink-stained gram-negative (right)
Gram-stain of gram-positive streptococci surrounded by pus cells