Fig. 2

FISH of a dermis biopsy shows single C. avidum cells located close to structures compatible with sweat glands, located at the border of the dermis to the subcutaneous fat tissue. The tissue section was hybridized with the panbacterial probe EUB338_Cy5 (mangenta), the C. acnes/ C. modestum/ C. namnetense/ A. thiooxidans/ M. chitae-specific probe PAC_FITC (green) and the C. avidum/ A. thiooxidans/ A. propionicum/ A. jensenii/ A. thoeni–specific probe PRAV_Cy3 (orange). Nucleic acids were stained with DAPI. a Overview of the biopsy, overlay of all fluorescence channels and background fluorescence allows orientation within the tissue (b). At higher magnification of the inset marked in (a), single rods are located at the border of the dermis and the subcutaneous fat tissue. c Inset of (b) showed the detected rods at higher magnification (d to g), the identical microscopic field as (c) with separate fluorescence channels, DAPI, Cy3, Cy5, and FITC, respectively. Note the detected rod was positive in DAPI (c), the PRAV (d), and EUB338 (e) probe, but showed no signal with PAC (f)