Microbial overgrowth in water perfusion equipment for esophageal/rectal motility

Background, There are few data on microbial levels in water used during the assessment of GI motility. Patients undergoing such procedures may be ingesting water with unacceptably high levels of bacteria. Methods: Samples of water from the reservoir and tubing from water perfusion motility equipment were taken and quantitatively assessed to determine the concentration of viable aerobic and facultative microorganisms. Interventions were evaluated to determine which reprocessing schedule ensures absence of overgrowth by microbes within the system during storage. Results: Bacterial overgrowth can occur in manometry systems with bacterial levels of greater than 104 colony-forming units (cfu)/mL in the water from both the reservoir and the tubing. Organisms detected included Serratia marcescens, Burkholderia species, and other gram-negative nonfermentors. Eradication of these organisms was difficult, and the only intervention that consistently ensured bacterial water levels below 200 cfu/mL (i.e., within potable water guidelines) was retrofitting of the pump/tubing with new components combined with a monthly hydrogen peroxide decontamination protocol and a daily drying protocol. Conclusions: The entire tubing path of motility equipment must be stored dry to prevent microbial overgrowth. Additionally, implementation of a motility equipment quality assurance program with water testing 3 to 4 times per year is recommended to ensure that overgrowth is not a problem.