Secondary bacterial infections of buruli ulcer lesions before and after chemotherapy with streptomycin and rifampicin

Buruli ulcer (BU), caused by Mycobacterium ulcerans is a chronic necrotizing skin disease. It usually starts with a subcutaneous nodule or plaque containing large clusters of extracellular acid-fast bacilli. Surrounding tissue is destroyed by the cytotoxic macrolide toxin mycolactone produced by microcolonies of M. ulcerans. Skin covering the destroyed subcutaneous fat and soft tissue may eventually break down leading to the formation of large ulcers that progress, if untreated, over months and years. Here we have analyzed the bacterial flora of BU lesions of three different groups of patients before, during and after daily treatment with streptomycin and rifampicin for eight weeks (SR8) and determined drug resistance of the bacteria isolated from the lesions. Before SR8 treatment, more than 60% of the examined BU lesions were infected with other bacteria, with Staphylococcus aureus and Pseudomonas aeruginosa being the most prominent ones. During treatment, 65% of all lesions were still infected, mainly with P. aeruginosa. After completion of SR8 treatment, still more than 75% of lesions clinically suspected to be infected were microbiologically confirmed as infected, mainly with P. aeruginosa or Proteus miriabilis. Drug susceptibility tests revealed especially for S. aureus a high frequency of resistance to the first line drugs used in Ghana. Our results show that secondary infection of BU lesions is common. This could lead to delayed healing and should therefore be further investigated

Analgesic efficacy of an ibuprofenreleasing foam dressing compared with local best practice for painful exuding wounds

Objective: To examine if wound aetiology has an effect on the pain-relieving properties of an ibuprofen-releasing foam dressing, which was previously shown to reduce pain inwounds of various aetiologies, compared with local best practice (LBP). Method: This was a secondary analysis of data from a multicentre, randomised, parallel group trial of patients with painful exuding wounds of various aetiologies. Wound aetiology was determinedatenrolment. Of 853 patients enrolled into the trial, 688 belonged to a wound aetiology subgroup that included > 25 patients and were included in the analysis reported here. Patients were randomised to a dressing containing 112.5mg of ibuprofen (ibuprofen foam) or to LBP for 5 days. Patients recorded pain relief and pain intensity daily. The main endpoint was the proportion of patients who, from day 1 to day 5, reported a summed pain reliefscore > 50% of the total maximum pain relief score (TOTPARD5>50%) and the corresponding number needed to treat (NNT) for each wound aetiology subgroup. Further analyses included the proportion of patients who, on a daily basis, reported pain relief > 50% of the maximum daily pain relief, the proportion of patients who, on day 5,experienced a reduction in pain intensity of > 50% of the maximum score (PIDD5>50%), and if PIDD5>50% was related to baseline pain intensity. Results: Patients were categorised by thefollowing five wound types: arterial, venous, and mixed arterial-venous leg ulcers, vasculitis and traumatic ulcers. The ibuprofenfoam dressing was associated with significantlygreater pain relief than LBP in all different wound aetiology subgroups, whether chronic or traumatic (acute). Overall, TOTPAR D5>50% was 55% in the ibuprofen foam group and 24% in the LBP group (p < 0.0001; NNT, 3.2). The pain intensity evaluations revealed similar results in favour ofibuprofen foam compared with LBP. No correlation was observed between PIDD5>50 and initial pain intensity. Conclusion: In this study, the ibuprofenfoam dressing was shown to consistently relievewound painin exuding wounds of various aetiologies, irrespective of basal painintensity.The data suggest that local pain reliefby an ibuprofenfoam dressing is possible in themost common, painful, exuding, chronic and acute/traumatic wounds and so is a safer alternative to systemic pain treatment. Conflict of interest: Of the ten authors involved inthe preparation of this manuscript, seven declare that theyhave no conflicts of interest. One is a member of the Wound AdvisoryForum for Coloplast A/S, Denmark. Two are employees of Coloplast A/S, Denmark

A novel chronic wound biofilm model sustaining coexistence of Pseudomonas aeruginosa

Chronic wounds are a large burden to patients and healthcare systems. Biofilm infections in chronic wounds are crucial factors leading to non‐healing of wounds. It is important to study biofilm in wounds and to develop effective interventions against wound biofilm. This study presents a novel in vitro biofilm model mimicking infected chronic wounds. The novel layered chronic wound biofilm model uses woundlike media and includes both Pseudomonas aeruginosa and Staphylococcus aureus, which have been identified as the most important pathogens in wounds. The model sustains their coexistence for at least 96 h. Microscopy of the model revealed microbial growth in non‐surface attached microcolonies as previously observed in vivo. The model was used to determine log(10)‐reduction for the use of an antimicrobial solution and antimicrobial dressings (containing silver or honey) showing moderate‐to‐low antibiofilm effect, which indicates better concordance with the observed clinical performance of this type of treatment than other widely used standard tests