Biofilm development by clinical isolates of Staphylococcus spp. from retrieved orthopedic prostheses.
BACKGROUND
Biofilms are considered the key factor in the development of implant-related infections. However, only a few reports have dealt with the ability of organisms isolated from such infections to develop biofilms in vitro.


METHODS
We evaluated different phenotypic techniques (2 microtiter plate assays and confocal laser scanning microscopy (CLSM) and genotypic techniques (detection of the ica operon) related to biofilm development by clinical isolates of Staphylococcus spp.


RESULTS
All 26 strains tested (from 23 specimens) were biofilm producers. Stepanovic test detected biofilm formation in 85% of the strains, microtiter plate assay in 65%, and CLSM in 39%. The ica operon was detected in 73% of all strains (all 13 S. aureus strains and 6 of the 13 coagulase-negative Staphylococcus strains). 7 ica-negative strains were biofilm-positive by phenotypic methods.


CONCLUSIONS
The detection of ica genes could not be related to the phenotypic ability of the strains to develop a biofilm in vitro, so both studies (genetic and phenotypic) are required for a better evaluation of the biofilm-producing ability of clinical strains of Staphylococcus isolated from orthopedic infections.
Departments of Clinical Microbiology, Fundación Jiménez Díaz-UTE, Madrid, Spain. jestebanmoreno@gmail.com
Jaime
J
Esteban
Diana
D
Molina-Manso
Iris
I
Spiliopoulou
José
J
Cordero-Ampuero
Ricardo
R
Fernández-Roblas
Antigoni
A
Foka
Enrique
E
Gómez-Barrena
D001422:Bacterial Adhesion / Q000502:physiology; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development; D006801:Humans; D018613:Microscopy, Confocal; D019736:Prostheses and Implants / Q000382:microbiology*; D016459:Prosthesis-Related Infections / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013210:Staphylococcus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology