Figure 1

Gram stains of four clinical isolates to illustrate the giant size and peculiar architecture of the blood isolate of Sarcina ventriculi (B). To demonstrate the size of the Sarcina cells other images (A, C, D) are presented for comparison at the same magnification x 100. Note that the size of Sarcinae is as big as that of yeast and much bigger than that of Finegoldia magna. A. Candida parapsilosis, staining from the colony. B. Sarcina ventriculi, staining from an anaerobic blood culture bottle, 2 images (isolated from the patient presented). The identification was based on 16S rRNA sequencing. C. Finegoldia magna, big anaerobic coccus, staining from the colony. D. Sarcina-like bacteria recovered from faeces of another patient with norovirus gastroenteritis, staining from the colony. The suspicion of Sarcinae was based on typical colony morphology and gram-staining. E. Sarcina ventriculi, staining from an anaerobic blood culture bottle (as picture B), one image taken with magnification 1000, oil objective. Note tetrad assembling. F. Zoomed image of the tetrad of Sarcina-like bacteria (from picture D).