Effects of Clindamycin on Adherence of Clostridium difficile to Human Embryonic Intestinal Cells
CHEMICAL RESEARCH DEVELOPMENT AND ENGINEERING CENTER ABERDEEN PROVING GROUND MD
Pagination or Media Count:
An in vitro assay system, consisting of monolayers of human embryonic intestinal cells HEI and Clostridium difficile, was used to observe cell surface and cytoplasmic interactions. Microorganism test conditions include toxin B positive 938 and toxin B negative 789 strains, each harvested from standard sheep blood agar SBA, casamino acids agar CAS, and CAS containing subinhibitory concentrations of clindamycin CAS-CL. Effects of toxin B were seen when organisms were harvested from SBA. Adherence and internalization were observed with organisms harvested from CAS and CAS-CL. Evidence of adherence andor movement into HEI cells was observed at 15, 30, 60, and 90 min time periods using the in vitro internalization assay, conventional scanning electron microscopy, transmission electron microscopy, and field emission scanning electron microscopy of freeze fractured preparations. Quantitative organism determinations, and the observed activity of microorganisms harvested from CAS and CAS-CL, revealed their capability to adhere to andor enter HEI cells. The toxin B producer, 938, harvested from CAS-CL, entered the cytoplasm and remained intact within it.
- *SCANNING ELECTRON MICROSCOPES
- IN VITRO ANALYSIS
- ELECTRON MICROSCOPY
- TOXINS AND ANTITOXINS