Local treatment of Dacron patch graft infected with biofilm-producing Staphylococcus epidermidis using antibiotic-releasing porous apatite ceramic: an experimental study in the rabbit.

Some Staphylococcus epidermidis strains produce an extracellular glycocalyx called biofilm and exhibit a high resistance to antibiotics due to this biofilm.1Bergamini T.M Bandyk D.F Govostis D Kaebnick H.W Towne J.B Infection of vascular prostheses caused by bacterial biofilms.J Vasc Surg. 1988; 7: 21-30PubMed Scopus (90) Google Scholar, 2D. Mack. Molecular mechanisms of staphylococcus epidermidis biofilm formation. J Hosp Infect 1999;43(Suppl):113-125Google Scholar, 3Schwank S Rajacic Z Zimmerli W Blaser J Impact of bacterial formation on in vitro and in vivo activities of antibiotics.J Antimicrob Chemother. 1998; 42: 895-898Google Scholar We previously reported the efficacy of local treatment with antibiotics-releasing apatite ceramic (TCP) for prosthetic graft infection by S aureus.4Sago T Mori Y Takagi H Iwata H Murase K Kawamura Y Local treatment of Dacron patch graft contaminated with Staphylococcus aureus using antibiotic-releasing porous apatite ceramic an experimental study in the rabbit.J Vasc Surg. 2003; 37: 169-174Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar, 5Murase K Hirose H Mori Y Takagi H Iwata H Sago T Graft-preserving treatment for vascular graft infected with Staphylococcus aureus with antibiotic-releasing porous apatite ceramic in the rabbit.J Vasc Surg. 2003; 38: 368-373Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar Usually S aureus does not produce biofilm. Afterwards, we extended our new treatment method to the other major prevalent pathogen, biofilm-producing S epidermidis. S epidermidis, American Type Culture Collection 35984, was used as the infecting organism. Teicoplanin (TEIC, Aventis Pharma S A, Germany) was used as the antibiotic. The minimum inhibitory concentration of TEIC for S epidermidis was 2 mg/mL. By using the same technique of our previous reports, Dacron grafts were patched in the anterior wall of the abdominal aorta of the rabbits. These animals were divided into the following four groups: (1) the NS group (n = 6), a no-treatment group with a sterile prosthetic vascular graft; (2) the NB group (n = 8), a no-treatment group with a prosthetic vascular graft infected with S epidermidis; (3) the TA group (n = 6), a group with a prosthetic vascular graft infected with S epidermidis, treated two weeks after the operation with TEIC (100 mg) locally administered on the graft; and (4) the TT group (n = 6), a group with a prosthetic vascular graft infected with S epidermidis, treated two weeks after the operation with TEIC-loaded TCP placed on the infected graft. The TT group received the same amount of TEIC (100 mg) as the TA group. Four weeks after the first operation, all the patched graft was removed from the abdominal aorta and cultured after its sonication. Cotton swabs of perigraft fluid and of the graft surface, tissue around the prosthetic vascular graft, and arterial blood were cultured. In the NS group, no bacteria were recovered by all culturing methods in all animals. In the NB group, perigraft effusion and poor graft incorporation were recognized in 5 of 8 (63%) animals. S epidermidis was recovered in 6 of 8 (75%) animals by sonication. In the TA group, all animals had normal anastomosis and normal graft incorporation. S epidermidis was recovered in 5 of 6 (83%) animals by sonication. In the TT group, all animals had normal anastomosis, normal graft incorporation, and no perigraft effusion. S epidermidis was not recovered in any animals. Significant differences in the infection rate were found between the NB group and TT group (P < .01) and between the TA group and the TT group (P < 0.05) (Fig). We found similar effectiveness against Dacron patch graft infection with biofilm-producing S epidermidis and efficacy of local treatment with antibiotics-releasing TCP for prosthetic graft infection.