Summary of studies comparing the effects of cleaning agents on Clostridium difficile spores
| STUDY | AGENTS INCLUDED | METHODS | OUTCOMES |
|---|---|---|---|
| Fawley et al,20 2007 | Anionic surfactant and NaDCC (1000 mg/L free chlorine)* Detergent and hypochlorite* NaDCC alone (1000 mg/L free chlorine)* Nonionic surfactant and phosphate Hydrogen peroxide (concentration not provided) | Solution of mature spores were exposed to cleaning agents for 0, 10, 20, and 30 min, cleaned then incubated anaerobically for 48 h; results interpreted in comparison to nonexposed control preparations | All 3 chlorine-containing agents inactivated vegetative cells and spores within 10 min of exposure; exposure to detergent (nonionic surfactant and phosphate) or hydrogen peroxide resulted in no difference in the number of viable spores compared with controls at 30 min |
| Perez et al,21 2005 | Chlorine dioxide equal to 600 mg/L free chlorine* Acidified bleach equal to 5000 mg/L free chlorine* Domestic bleach in 3 dilutions (5000 mg/L free chlorine, 3000 mg/L free chlorine, and 1000 mg/L free chlorine)* 7% hydrogen peroxide | Spores were grown anaerobically and heated to kill vegetative cells; stainless steel disks were contaminated with spore suspension and exposed to cleaning agents for 10, 15, or 30 min; after neutralizing the cleaning agent, agar plates were inoculated with the contents of each disk and incubated for 2 and 5 d | Acidified bleach, regular bleach (5000 mg/L free chlorine), and 7% hydrogen peroxide inactivated spores within 10 min of exposure; chlorine dioxide and domestic bleach at 3000 mg/L and 1000 mg/L free chlorine were all able to inactivate spores; however, exposure times were longer (up to 30 min) |
| Block,22 2004 | 0.26% peracetic acid—a biocide with manufacturer claims of sporicidal activity NaDCC tablets (1000 mg/L free chlorine)* | Spores were grown anaerobically on blood agar plates and harvested by suspending the cultures in methanol; equal aliquots of spore suspensions were dried on stainless steel disks and PVC floor covering material; each material was exposed to the test solutions for 3, 5, or 10 min, after which time remaining viable spores were counted | Neither agent was effective in eradicating the spores, although both agents reduced spore counts; on stainless steel, at 10 min, peracetic acid exposure resulted in a 6 log10 reduction in viable spores compared with a 0.7 log10 reduction in viable spores with NaDCC (P = .011); on PVC, the log10 reduction in viable spores for peracetic acid (2.7) and NaDCC (0.9) were not statistically different |
| Wullt et al,23 2003 | 70% isopropanol 2% glutaraldehyde 0.26% peracetic acid Acidified nitrite | C difficile bacteria and spores were grown anaerobically on blood agar for 48 h; vegetative cells were killed using ethanol, and spores were suspended in water to which disinfecting agents were added for 5, 15, and 30 min before being inactivated | Glutaraldehyde, peracetic acid, and acidified nitrite reduced spore counts by 99% after 15-min exposure; glutaraldehyde has been associated with dermatitis and symptoms of asthma secondary to exposure; isopropanol showed no effect on spore viability even after 30-min exposure |
NaDCC—sodium dichloroisocyanurate, PVC—polyvinyl chloride.
↵* Chlorine-releasing product.