The effect of bacterial colonization on venous ulcer healing.

To determine the effect of bacterial colonization on venous ulcer healing, 82 patients with 100 venous ulcerated limbs were each studied prospectively for six months. Despite bacteriological swab results, topical or systemic antibiotics were not administered unless cellulitis supervened. Initial ulcer size, length of ulcer history and time to complete healing of colonized and uncolonized ulcers were determined and compared. Organisms were cultured from 83 limbs prior to commencement of treatment, the commonest isolates being Staphylococcus aureaus (48%), mixed coliforms (28%), Pseudomonas aeruginosa (21%) and anaerobes (17%). When compared with ulcers with no bacterial growth, colonized ulcers were of longer duration (p [symbol: see text] 0.01), had a larger initial size (p [symbol: see text] 0.001) and had significantly longer healing time (p [symbol: see text] 0.001). When analysed individually beta-haemolytic streptococci, anaerobes, Staphylococcus aureus and coliforms were associated with delayed healing. Delayed healing was not found with Pseudomonas aeruginosa, although pseudomonas-colonized ulcers were significantly larger and of longer duration than uncolonized ulcers. Bacterial colonization is associated with delayed venous ulcer healing. To further clarify the pathogenicity of colonizing bacteria, however, the effect of their eradiction on healing of venous ulcers needs to be established.