THU0426 CLINICAL CHARACTERISTIC OF INFECTIOUS ULCERATION OVER TOPHI
Authors: Z. Huang, T. LI, X. Liu
Journal: Annals of the Rheumatic Diseases (2020)

Background: Infection in ulceration over tophi is the leading cause of sepsis in patients with gout, which is the main indication for surgery. Additionally, patients with infection will significantly prolonged wound closure time compared with those without infection. Investigation of infection in ulceration over tophi will improve our understanding of this critical issue. Objectives: To describe the microbiological profile in ulceration over tophi, antibiotic susceptibility patterns of causative agents, and to study the prediction of infection in ulceration over tophi among patients with gout. Methods: Patients with ulceration over tophi were prospectively enrolled. The clinical characteristics were recorded and microbiological specimens were taken on admission. Specimens were cultured for aerobic and anaerobic bacteria, and antibiotic susceptibility testing was performed for the culture isolates. Patients were divided into 2 groups according to having infectious ulceration or not and the potential risk factors for infectious ulceration over tophi were examined using univariate and multivariate logistic regression analyses. Results: A total of 82 patients were included for analysis. 46 pathogens were isolated from 39 (47.6%) patients, among which the top 3 were Staphylococcus aureus (43.5%), Pseudomonas aeruginosa (17.4%) and Enterococcus faecalis (13.0%). Overall, the Gram-positive bacilli were more sensitive to gentamicin (81.5%), amikacin (88.9%), trimethoprim/sulfamethoxazole (92.6%), nitrofurantoin (96.3%), linezolid (100.0%), teicoplanin (100.0%) and vancomycin (100.0%) whereas penicillin, oxacillin and ampicillin were 66.7% to 77.8% resistant. The Gram-negative bacilli were more sensitive to amikacin (84.2%), cefoperazone/sulbactam (84.2%) and meropenem (89.5%) whereas ampicillin, amoxicillin/clavulanate, cefotaxime, cefazolin, piperacillin, trimethoprim/sulfamethoxazole and tetracycline were 68.4% to 100% resistant. Patients with infection had a higher rate of smoking history and type 2 diabetes, with higher levels of erythrocyte sedimentation rate, C-reactive protein and leucocyte, and lower level of albumin. In stepwise logistic regression analysis, type 2 diabetes (adjusted OR 5.064; 95% CI = 1.430 to 17.928) and albumin level (adjusted OR 0.855; 95% CI = 0.782 to 0.935) were independent predictors of infection in ulceration over tophi. Conclusion: Infection is common in ulceration over tophi. Different antibiotic susceptibility patterns were observed in Gram-positive bacilli and Gram-negative bacilli. Type 2 diabetes and low albumin level were associated with an increased risk of infection in ulceration over tophi. The data in this study will be beneficial for tailoring infection control measures in a way that improves outcomes of ulceration over tophi. References: [1]Huang Z, Liu X, Liu Y, et al. Clinical characteristics and risk factors of ulceration over tophi in patients with gout. International journal of rheumatic diseases 2019;22:1052-7. [2]Xu J, Zhu Z, Zhang W. Clinical characteristics of infectious ulceration over tophi in patients with gout. The Journal of international medical research 2018;46:2258-64. Table 1. Bacteria isolated from initial ulceration specimens taken on the first admission. Bacteria Number* (n = 46) Proportion (%) Gram-positive bacilli 27 58.7 Staphylococcus aureus 20 43.5 Enterococcus faecalis 6 13.0 Streptococcus mutans 1 2.2 Gram-negative bacilli 19 41.3 Pseudomonas aeruginosa 8 17.4 Klebsiella pneumonia 4 8.7 Enterobacter cloacae 3 6.5 Escherichia coli 2 4.3 Acinetobacter baumannii 2 4.3 * Number of ulceration Disclosure of Interests: : None declared