The purpose of the study was to find out if isolation carts were serving as a means of cross infection. Literature pertaining to sources of possible contamination on hospital units written in the past five years were reviewed.

Using the descriptive survey as the method of study, effort was made to find out if isolation carts were a means of cross infection on the hospital unit. Two laboratory cultures were obtained from both door pulls on all isolation carts used by nursing units. This was done over a three month period from December 12, 1963 to March 11, 1964. The first culture was taken before the cart was put into use by the nursing units and served as a control. The second culture was taken after the carts had been in use by nursing units for forty-eight hours.

For those patients isolated because of specific organisms, effort was made to grow these organisms. For patients isolated for their own protection, effort was made to grow pathogens which could be transmitted to the patient via the isolation cart.

To obtain specimens from door pulls, sterile swabs dampened in trypticase soy broth solution were swabbed over the entire area of both door pulls. The swabs were then replaced in the broth solution and stirred around so the bacteria would become suspended in it. The mouth of the culture tube was then passed through a flame to insure sterility of the procedure. Following this the specimens were sent to the clinical laboratory where they were innoculated on blood agar plates and in thio- glycolate broth. These were incubated at 37.5° Centigrade for seventy-two hours. Plates were examined daily for any bacterial growth. Any growth seen was restreaked on new blood agar plates. Smears were made on colonies on all plates that showed any growth. The pigment and hemolysis of the organisms were noted. These smears were stained by the gram stain method and examined under the microscope. The gram positive micrococci were classified by streaking them on mannitol salt agar. A coagulase test was run on those organisms that fermented the mannitol.

Sixteen isolation carts qualified for this study. Of the control cultures, thirteen were negative for bacterial growth. Three showed small amounts of Staphylococcus epidermidis. This is a nonpathogenic organism which probably came from the hands of whoever cleaned the cart.

Of the forty-eight hour cultures, six were negative for any bacterial growth. Eight showed growths of Staphylococcus epidermidis and the remaining two showed growths of Staphylococcus aureus coagulase negative. The latter organism is also nonpathogenic. Most likely these organisms came from those persons using the isolation cart.

These data indicated that door pulls did not harbor pathogenic organisms. Statistical analysis indicated an eighty percent probability of significance that there were organisms present on the door pulls after forty-eight hours of use. Because these were nonpathogenic organisms, it could be that these organisms could be acquired just as readily had the carts remained in Central Service for this forty-eight hour time lapse.

It was recommended that the study be carried out again under epidemic conditions; that a one to two inch wide vertical strip running parallel to the door’s edge be cultured; and that articles inside the isolation cart be cultured.

LLU Discipline





Graduate School

First Advisor

Dorothy M. Kuester

Second Advisor

Ruby Dybdahl

Third Advisor

Lucile L. Lewis

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Cross Infection



Page Count

vii; 70

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives