Preliminary Study On The Diagnosis And Intervention Of Chronic Wound Bacterial Biofilm

[Objective]In this study, we selected the chronic wounds suspected of bacterial biofilm, through the clinical judgment combined with the analysis of bacterial culture results was to prove the presence of bacterial biofilm in chronic wounds and to analyses bacterial species distribution in bacterial biofilm.2 cases from bacterial culture positive cases were for the clinical intervention and provide relevant basis for future clinical practice.[Methods] 1. The object of study:From 2013 January to 2015 February, patients were selected in wound care center of Nanjing Jingling hospital with chronic wound bacterial biofilm. After the inclusion and exclusion criteria for screening,the patients signed informed consent, finally we included 148 patients with a total of 8 kinds of wound:surgical site infection, pressure ulcer, traumatic wound, diabetic foot ulcer, immune disease wound, venous ulcer, radiation injury and atypical wound; 82 cases male,66 cases female; 2. Clinical assessment:systemic evaluation of patients mainly includes the assessment of patients with and without underlying diseases and treatments; dynamic observation of abnormal biochemical indexes; physical activity ability of the patients. The local wound assessment was mainly observed for wound bed area, odor and quantity, edema and stealth and record.3. Preexperiment was to determine if bacterial culture sampling process can judge the wound has bacterial biofilm:according to the standards of clinical and laboratory diagnosis of bacterial biofilm on the 2012 Mexico World Conference announcement of bacterial biofilm infection,20 cases firstly were selected for preexperiment, after explaining the purpose and method to the patients, the researcher strictly take samplings in accordance with the unified method:first with 0.5% iodophor cleaned the wound and surrounding skin 2-3 times, and normal saline washed the same range 2-3 times, the test tube removed aseptic cotton for the word "Z"from one end to the other end of the wound, to ensure getting secretions, the sampling cotton swab went into the tubes without contamination. Samples were immediately delivered to the person responsible for the bacteria culture in microbial laboratory, the wound biofilm was doubted if bacterial culture was positive. At the same time, taking the central soybean grain size tissue of 20 cases of wound, neutral formalin fixed, were sent to the pathology department for DNA extraction by PCR technology for identification of species of pathogenic bacteria. Specimens stained with HE were by electron scanning microscope for structure, comparing biological membrane structure diagram with the foreign reports, the results confirmed the wounds had the bacterial biofilm, therefore 148 cases can be verified by the general bacterial culture,and the analysis of the characteristics of bacterial biofilm.4. Clinical intervention:the implementation of standardized care was for 148 cases with the sharp debridment and using the silver dressing.2 cases selected from the bacterial culture positive cases were for molecular technique.5. The observation indexes:the standardized clinical intervention rates were healing rate, dropout rate, mortality and referral rates.2 representative wound cases was mainly bacterial culture results, the wound area, wound fluid pH value and temperature of the local wound.6. The statistical analysis:wound type/position/severity, bacteria in the biofilm bacterial species, resistant strains employed were described by constituent ratio (%), the results of bacterial culture with descriptive statistics for positive rate and negative rate (%).The follow-up effects of wound were expressed as a percentage.[Results] 1.148 cases of 8 chronic wound bacterial biofilm, according to bacterial growth ratio distribution is as follows:SSI, traumatic injury, pressure ulcer, immune disease wound, VLU, untypical wound, DFU, radiation injury; the wound involving the muscle layer was easily lead to bacterial biofilm.2. The positive rate results of bacterial culture of 148 cases of chronic wound bacteria in biofilm was 66%, more common in Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli.3. In 98 cases of bacterial culture positive cases were isolated from 86 kinds of resistant bacteria and resistance to different antibiotics, ranking top three was Staphylococcus aureus, Pseudomonas aeruginosa and Proteus mirabilisand; 4. Of 148 cases, the wound healing rate was 62.2%, the mortality 4.7%, the dropout rate was 7.4%, the referral rate was 13.5%,2 cases of wound healed well with the clinical intervention.[Conclusion] 1.According to the clinical manifestations of chronic wound bacterial biofilm and bacterial culture results can judge whether the existence of bacterial biofilm in the wound infection;2. the multiple of the presence of bacteria in chronic wound bacterial biofilms may cause prolonged unhealing of the wound.3. Debridement combined with silver antimicrobial dressing can effectively remove bacteria biofilm in chronic wound preliminarily.