Evaluation of Microbial Growth in Hospital Textiles Through Challenge Test

Introduction: Ensuring the microbiological quality of textiles is an important requirement for health care facilities. The present study examines the way transport times and temperatures influence microbial growth in textiles. Therefore, the effectiveness of washing and disinfection processes has also been studied. Methods: Microbial Challenge Tests were set up through the artificial contamination of different dry and wet textiles which were stored at different temperatures. The bacterial concentration was evaluated in well-defined time phases aimed at simulating the time it took for the textiles to be transported from the hospital facilities to the reconditioning unit. Three times were therefore considered from T = 0 inoculation moment to T = 72 h post inoculation. At the end of each time, the increase in bacterial concentration was assessed by means of microbiological cultures, using selective media for the enumeration of each type of inoculated microorganism. Results: In all the contaminated textiles the bacterial concentration remained unchanged at a temperature of 4 °C, while at 22 °C and 37 °C there was a significant increase (p < 0.05) starting from 8 h of storage. In these textiles, the microorganism that showed the greatest growth capacity was P. aeruginosa with average initial concentration values of 104 CFU/cm2 and a final concentration of 1.5 × 105 CFU/cm2 at 22 °C and 1 × 105 CFU/cm2 at 37 °C 72 h after inoculum. Conclusion: The data highlights the fact that the degree of contamination in textiles does not undergo an increase when transport takes place at a controlled temperature. Refrigerated transport of hospital textiles is thus a desirable preventive measure to keep microbiological risk under control.