1,721,186 research outputs found
Antibiotic resistance in exopolysaccharide-forming Staphylococcus epidermidis clinical isolates from orthopaedic implant infections
No full textBiomaterials. 2005 Nov;26(33):6530-5.
Antibiotic resistance in exopolysaccharide-forming Staphylococcus epidermidis clinical isolates from orthopaedic implant infections.
Arciola CR, Campoccia D, Gamberini S, Donati ME, Pirini V, Visai L, Speziale P, Montanaro L.
Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Via di Barbiano 1/10, 40136 Bologna, Italy. [email protected]
The opportunistic pathogen Staphylococcus epidermidis is able to produce biofilm and to frequently cause implant infections. In recent years, it has also exhibited an increasing antimicrobial drug resistance. Here, the resistance to a panel of 16 different antibiotics in 342 clinical strains of S. epidermidis from orthopaedic implant infections has been investigated. The isolates were pheno- and genotyped for extracellular polysaccharide production, relevant to staphylococcal biofilm formation, in order to ascertain possible associations with antibiotic resistance. Approximately 10% of the isolates were found to be sensitive to all screened antibiotics. In all, 37-38% were resistant to beta-lactams such as oxacillin and imipenem, while the resistance to penicillin, ampicillin, cefazolin, cefamandole, was consistently observed in over 80% of the
strains. Erythromycin- and clindamycin- resistant strains were approximately 41% and 16%, respectively. Of the isolates, 10% was resistant to chloramphenicol, 23% to sulfamethoxazole and 26% to ciprofloxacin. Resistance to vancomycin was never observed. Interestingly, exopolysaccharide-producing strains exhibited a significantly higher prevalence in the resistance to the four aminoglycosides (gentamicin, amikacin, netilmicin, tobramycin), to sulfamethoxazole and to ciprofloxacin with respect to non-producing isolates. Moreover, multiple resistance to antibiotics was more frequent among exopolysaccharide-forming strains
A multiplex PCR method for the detection of all five individual genes of ica locus in Staphylococcus epidermidis. A survey on 400 clinical isolates from prosthesis-associated infections
No full textJ Biomed Mater Res A.
A multiplex PCR method for the detection of all five individual genes of ica locus in Staphylococcus epidermidis. A survey on 400 clinical isolates from prosthesis-associated infections.
Arciola CR, Gamberini S, Campoccia D, Visai L, Speziale P, Baldassarri L, Montanaro L.
Research Unit on Implant Infections, Rizzoli Orthopedic Institute, Via di Barbiano, 1/10, 40136 Bologna, Italy.
[email protected]
In Staphylococcus epidermidis, ica locus encodes for the synthesis of a polysaccharide intercellular adhesin (slime or biofilm). A multiplex polymerase chain reaction (PCR) for the detection of the five individual genes of ica locus was developed, with the aim to probe the set of genes in a large collection of Staphylococcus epidermidis clinical isolates. Single representative fragments
for icaR, icaA, icaD, icaB, and icaC genes were selected. Multiplex PCR was applied to two reference Staphylococcus epidermidis strains [the non-biofilm-forming ATCC 12228 and the biofilm-forming ATCC 35984 (RP62A)] and to 400 clinical isolates of Staphylococcus epidermidis from orthopedic prosthesis associated infections. The gene profile was compared with the phenotypic biofilm-forming ability, evaluated by means of an optimized Congo red agar (CRA) plate test. Among the clinical isolates, 228 (57%) turned out completely ica positive and were biofilm producing. Among the 172 non-biofilm-forming strains (43%), 164 (41%) were completely ica negative and 8 strains (2%) harbored all five ica genes. The ica locus thus proves to be a cluster of strictly linked genes, without any evidence of single gene deletion.
(c) 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Analysis of new synthetic electrospun scaffolds for applications in skeletal muscle tissue engineering
No full textElectromagnetically enhanced coating of a sintered titanium grid with human SAOS-2 osteoblasts and extracellular matrix
No full textThe surface modification of a sintered titanium scaffold could play an important role in bone tissue engineering. In this study we have followed a biomimetic strategy where electromagnetically stimulated human SAOS-2 osteoblasts proliferated and built their extracellular matrix on a sintered titanium grid. In comparison with control conditions (standard cell culture incubator, where no electromagnetic stimulus was detectable), the electromagnetic stimulus (magnetic field, 2 mT; frequency, 75 Hz) increased the cell proliferation and the surface coating with decorin, osteopontin, and type-I collagen. The electromagnetic stimulus aimed at obtaining a better surface coating of the sintered titanium grid in terms of cell colonization and bone matrix. The superficially modified biomaterial could be used, in clinical applications, as an implant for bone repair
Editorial: Cells, biomaterials, and biophysical stimuli for bone, cartilage, and muscle regeneration, volume II
No full text
Physically enhanced coating of a titanium plasma-spray surface with human SAOS-2 osteoblasts and extracellular matrix
No full textSeveral studies suggest that the modification of a titanium surface could play an important role in bone tissue engineering. In this study we have followed a biomimetic strategy where ultrasonically or electromagnetically stimulated human SAOS-2 osteoblasts proliferated and built their extracellular matrix on a titanium plasma-spray surface. In comparison with control conditions, the ultrasonic stimulus (power, 149 mW; frequency, 1.5 MHz) and the electromagnetic stimulus (magnetic field, 2 mT; frequency, 75 Hz) increased the cell proliferation and the surface coating with type-I collagen. The physical stimuli aimed at obtaining a better modification of the rough titanium plasma-spray surface in terms of cell colonization and coating with bone matrix. The superficially modified biomaterial could be used, in clinical applications, as an implant for bone repair
- …
