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From 50 infected surgical wounds of orthopaedic patients, 43 (86%) staphylococcal strains were isolated. 34 of all these staphylococci belonged to Staphylococcus aureus species (i.e. 68 % of all isolates from surgical wounds; 79% of staphylococcal isolates); 9 were coagulase-negative staphylococci (i.e. 21% of all isolates from surgical wounds; 18% of staphylococcal isolates). Among microorganisms isolated from the wounds we also found 2 (4%) of the Enterobacteriaceae family; 2 (4%) of the Pseudomonas genus; 3 (6%) of the Streptococcus genus. Thus, orthopaedic surgical wounds were infected by staphylococci (mainly S. aureus) more frequently than by other micro-organisms. All the staphylococcal strains were screened for methicillin resistance by agar disk diffusion testing and for the presence of mecA gene responsible for methicillin resistance by PCR. 32% of the S. aureus and 33% of the S. epidermidis strains resulted methicillin resistant and mecA-positive. The data confirm the diffusion of methicillin resistant S. aureus in surgical site infections and shows that the so-called "new pathogens", i.e. S. epidermidis and other coagulase-negative staphylococci, also exhibit a frequent and hazardous methicillin-resisting ability.

Deposition and aggregation of lachrymal proteins on the contact lens surface can promote bacterial adherence. Lysozyme is the major tear protein and is also mainly responsible for the formation of protein deposits on contact lenses. Nonsteroidal anti-inflammatory drugs (NSAID) prevent protein aggregation. The effect of a water-soluble NSAID drug on bacterial adherence to high-water-content/ionic disposable contact lenses was examined in a radiolabeling study. Dose-related inhibition of adherence of Staphylococcus aureus, S. epidermidis, and Pseudomonas aeruginosa on both pretreated lenses and after adding the drug to the medium was investigated. When the drug was added to the media, maximal inhibition of S. aureus adherence was observed in trypticase soy broth (59-98% at the lower and higher drug concentrations, respectively); inhibition progressively decreased in calf aqueous humor (48-75%), lysozyme (34-63%), and saline (12-20%) solutions. Inhibition of adherence varied with the three bacterial species; it was maximal with S. aureus, intermediate with S. epidermidis, and minimal with P. aeruginosa. When lenses were pretreated with the drug, consistent, and even higher, inhibitory effects were observed. The results suggest that water-soluble NSAIDs could be used in preventive treatments for conjunctivae and corneal infections in contact lens wearers, and may provide a clue as to which compounds might inhibit protein interaction and bacterial adhesion.

The authors have quantitatively evaluated and compared in vitro the Staphylococcus aureus and Staphylococcus epidermidis strain adhesiveness on various types of silicone used in surgery. The results show that there are some adhesiveness differences between the two assayed strains (S. epidermidis adhesivenessS. aureus adhesiveness) and among silicone types (adhesiveness on soft siliconesadhesiveness on hard silicones). However all silicones are suitable substrata for in vitro bacterial adhesion.

In surgical divisions, where you can find the highest percentage of hospital infections, the surgical wounds are definitively the most frequent localization. The aim of our study was to evaluate whether bacterial-biomaterial interactions could influence the growth of infections in sutured tissues. We prepared a method for in vitro bacterial adhesiveness testing based on turbidimetric analysis. The results obtained show a different grade of bacterial adhesion in relation to physical and chemical characteristics of the material examined.