A survey of Gram-negative bacteria survival on hospital fabrics and plastics

One critical factor for the transmission of microorganisms from person to person or from the environment to a person (patient or health care worker) is the ability of the microbe to survive on an environmental surface. The purpose of this study was to determine the length of survival of various gram-negative bacteria on fabrics and plastics commonly used in hospitals. Seven materials were tested: smooth cotton (clothing), cotton terry (towels), 60% cotton-40% polyester blend (scrub suits and lab coats), polyester (drapes), 75% nylon-25% spandex (pressure garments), polyvinyl (splash aprons), and polyurethane (keyboard covers). The following bacteria were tested: Pseudomonas aeruginosa, Escherichia coli:, Klebsiella pneumoniae, Serratia marcescens, Proteus mirabilis, Acinetobacter species, and Enterobacter species. Swatches of the materials were inoculated with defined amounts of bacteria and assayed at regular intervals. Survival was dependent on the bacterium, its inoculum size, and the material tested. At 10(2) microorganisms per swatch, bacteria survived from less than 1 hour to 8 days. At 10(4) to 10(5) bacteria per swatch, survival ranged from 2 hours to more than 60 days. These findings emphasize the need for careful disinfection and conscientious contact control procedures in areas that serve immunosuppressed individuals, such as patients with burn injuries.