Sporicidal activity of disinfectants as one possible cause for bacteria in patient-ready endoscopes.
Four endoscopes were cleaned by an experienced endoscopy technician using an enzyme detergent solution with brushing, rinsing with tap water, and then high-level disinfection in an automatic endoscope reprocessing machine using CIDEX orthophthalaldehyde solution (CIDEX OPA). After disinfection, the channels of these patient-ready endoscopes were flushed with sterile neutralizing medium, brushed with a sterile brush, and then flushed again with sterile medium. The effluent from each flush was collected in sterile bottles, immediately returned on ice to a laboratory, and tested for the presence of bacteria. An average of about 200 colony-forming units of bacteria were recovered from each endoscope. Upon staining and microscopic examination, 3 of these colonies were spore-forming bacteria, and 7 colonies were nonspore-forming bacteria. These results suggest that the endoscopes might have been contaminated with a biofilm. Bacterial biofilms have been speculated to commonly occur in endoscopes as a result of the many possible inadequacies of cleaning, disinfecting, rinsing, drying, storage, and other functions associated with the difficulties of reprocessing endoscopes. As one possible cause for a biofilm, three high-level disinfectants (CIDEX activated dialdehyde solution, CIDEX OPA, and Aldahol high-level disinfectant) were tested for their sporicidal activity against high-protein or low-protein cultures of spore-forming bacteria in suspension. The potential importance of killing spore-forming bacteria within a practical exposure time in order to prevent the formation of biofilms is discussed.
Miner
Norman
N
MicroChem Laboratory, Inc., Euless, Texas 76040, USA. nminer@microchemlab.net
Harris
Valerie
V
Ebron
Towanda
T
Cao
Thuy-Dung
TD
D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D003013:Clostridium / Q000187:drug effects / Q000254:growth & development; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000592:standards*; D004203:Disinfection / Q000379:methods / Q000592:standards; D004353:Drug Evaluation, Preclinical; D020776:Endoscopes, Gastrointestinal / Q000382:microbiology*; D004866:Equipment Contamination / Q000517:prevention & control*; D005976:Glutaral / Q000592:standards*; D017408:Guidelines as Topic; D006801:Humans; D013171:Spores, Bacterial / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors; D009764:o-Phthalaldehyde / Q000592:standards
D004202:Disinfectants; D009764:o-Phthalaldehyde; D005976:Glutaral