PMC8329477_01
Culture, Gram stain, and biofilm formation of C. sputigena clinical isolate.. A.C. sputigena isolate from patient 1 (C1) demonstrates gray-colored non-hemolytic colonies on a blood agar plate (2x) after 48 h incubation. B. At higher magnification (10x), swarming nature of the colonies can be appreciated. C.C. sputigena demonstrate thin, gram-negative bacilli morphology in smears prepared from the blood agar plate in A (1000x). D. Bar graph depicting average biofilm production quantities for the C1 and a laboratory-adapted reference strain (R1) at 24 and 48 h incubation. Error bars represent standard error of the mean and statistical differences assessed by Mann Whitney test (****, p < 0.0001). Note, panels A-C were generated from iPhone 12 Pro Max, Wide (1x) Lens with Moment 10x Macro Lens and Olympus DP74 microscope. Image enhancement performed with Affinity Photo, Pixelmator Pro and Topaz Labs Sharpen AI software.
gr1.jpg
PMC8329477_01_gr1.jpg
fig0005
Subculture to trypticase soy agar with 5 % sheep blood (blood agar), chocolate, and MacConkey agars with incubation at 36  C in 5 % CO2 yielded growth on blood and chocolate agars (Fig. 1A, B) approximately 24 h later. Evaluation of the growth demonstrated gram-negative bacilli (Fig. 1C), and the isolate was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS; BD  Bruker MALDI Biotyper  platform) as Capnocytophaga sputigena with a score of 2.44. We found that biofilm production of the clinical isolate was significantly higher than that of the reference strain at both 24 h and 48 h of incubation (p < 0.0001) (Fig. 1D).