Relationship between bacterial adhesion to prosthetic valve materials and bacterial growth

Yunchao HUANG; Kaiyun YANG; Yujie LEI; Guangqiang ZHAO; Xiaoming LI; Jia GAO

ABSTRACT

BACKGROUND:

Studies have demonstrated that prosthetic valve endocarditis is primarily caused by bacteria adhering on the surface of the materials.Thus,the relationship of prosthetic valve materials with bacteria adhesion and growth is an important subject.

OBJECTIVE:

To explore the influence of prosthetic valve materials on bacteria growth through observing the relationship of bacteria adhesion on prosthetic valve materials and bacteria growth.DESIGN,TIME AND

SETTING:

Repetitive measurement was performed at the Department of Cardiac and Thoracic Surgery,Third Hospital of Kunming Medical College from January to March 2001.MATERIALSTerylene(Dacron)was purchased from Man-made Blood Vessel Laboratory of Suzhou Weaves Belt Factory;polytetrafluoroethylene was provided by Teflon-GoreTexW.L.Gore & Associates,Inc.Arizona,USA;pyrolytic carbon was provided by Department of Biological Material of Sichuan Union University;staphylococcus anreus,Escherichia coli,staphylococcus epidermidis,and Pseudomonas aerugmosa were prepared by our laboratory.

METHODS:

The growth curve of staphylococcus aureus,staphylococcus epidermidis,Escherichia coli and Pseudomonas aeruginosa on dacron,pyrolytic carbon and pelytetrafluoroethylene were quantitatively determined respectively by plate counting and gamma.ray counting of 125 Ⅰ radiolabeled bacteria in vitro.Bacteria growing normally served as control.All bacteria were cultured for 30 hours,and bacteria concentration was determined every 2 hours.In addition,the adhesive capacities of foMr kinds of bacteria on dacron,pyrolytic carbon and polytetrafluoroethylene were detected Escherichia coli and Pseudomonas aeruginosa on dacron,pyrolytic carbon and polytetrafluoroethytene.

RESULTS:

There were no significant differences in adhesive capacities of each bacterium on dacron,pyrolytic carbon and polytetrafluoroethylene at the same time point(P>0.05).The differences in growth curve of four kinds of bacteria on prosthetic valve materials were not remarkable compared to the control(P>0.05).Different bacteria showed different adhesion degree on the materialsstaphylococcus aureus exhibited strongest adhesion on dacron;staphylococcus epidermidis on pyrolytic carbon;Escherichia coli on dacron.The adhesive capacity of Pseudomonas aerugmosa on dacron reached peak within 12 hours,and gradually decreased,but maintained strong adhesion on the other materials.The adhesive capacmes of four bacteria on the materials did not increase or maintain with time.

CONCLUSION:

The adhesive capacity of one bacterium to different artificial valve materials and different bacteria to one prosthetic valve materials is different.The materials.show little influence on bacterium growth cycle.