Acta Vulnologica 2011 March;9(1):25-36

Copyright © 2011 EDIZIONI MINERVA MEDICA

language: English, Italian

Chronic infected skin lesions, micro-organisms and bacterial resistance

Nebbioso G., Petrella F., Caprarella E., Bonat F., Costagliola C., Busalacchi A.

Azienda Sanitaria Locale Napoli 1, Napoli

Aim. Infection is one of the most frequent causes of the delayed healing of chronic skin lesions. This study analyses 231 samples, by seeding in selective and inhibitory terrains (Oxoid) to identify bacteria and fungi, considering as positive any samples that presented a growth of at least 104 cfu/mL.
Methods. Samples were collected by swab and/or the technique of irrigation/aspiration from the beds of skin ulcers with various etiologies (diabetic, venous, arterial, pressure ulcers, vasculitic) of 226 patients and subsequent antibiogram.
Results. The results reveal that the Gram-positive micro-organisms are most frequently responsible for the infection, followed by Gram-negative and fungi. In various lesions, polymicrobial flora was noted, with the isolation of 298 germs, while only 14 samples were negative. Among the gram-positives, the most numerous were the Staphylococci, followed by Enterococci and Streptococci; while among the gram-negatives Pseudomonas aeruginosa was the most abundant. More than half of the Staphylococci were resistant to oxacillin and also to other molecules such as gentamicin, norfloxacin, erythromycin and levofloxacin. The Enterobacteria isolated have proved to produce ESBL and resistant to all penicillins and cephalosporins except for cefoxitin. None of the Pseudomonaceae was sensitive only to colistin. The yeasts did not reveal particular resistance to the molecules tested.
Conclusion. The 212 positive patients were treated with specific systemic antibiotic therapy, the base of the antibiogram and local therapy with iodine-based products and dressings containing silver, never overlooking a multidisciplinary approach to lesions. Approximately 40% of ulcers healed completely, while the remainder improved significantly.