Drug resistance and risk factors of multidrug-resistant organism in chronic osteomyelitis: a multi-center retrospective study / 中华创伤骨科杂志

ABSTRACT

Objective:To investigate the spectrum, drug resistance and risk factors of multidrug resistant organism (MDRO) in chronic osteomyelitis.Methods:A retrospective study was conducted by cluster sampling to analyze the 414 patients with chronic osteomyelitis who had been admitted to Department of Orthopaedics, The Second Hospital Affiliated to Shanxi Medical University, Department of Orthopaedics, The People's Hospital of Shanxi Province, Department of Traumatology, Yuncheng City Hospital, and Department of Orthopaedics, Linfen City Hospital from January 2016 to December 2021. The patients were assigned into 2 groups according to whether MDRO had been detected or not. In the MDRO infection group of 150 cases, there were 118 males and 32 females with an age of (48.8±16.2) years; in the non-MDRO infection group of 264 cases, there were 194 males and 70 females with an age of (46.0±17.8) years. The characteristics of bacterial spectrum and drug resistance in MDRO infection were described and analyzed. The 2 groups were compared in terms of clinical data like gender, age, course of disease, body mass index, history of antibiotic use before admission, combined internal diseases, combined trauma, and length of hospital stay. The items with P<0.05 were included in a multivariate logistic regression model to explore the risk factors for MDRO infection. Results:Pathogenic bacteria (331 strains) were detected in 286 of the 414 patients with chronic osteomyelitis, and infection with 168 strains of MDRO was detected in 150 of the 286 patients, yielding a detection rate of 50.8% (168/331). Of the 168 strains of MDR, 129 (76.8%, 129/168) were Gram-positive and 39 (23.2%, 39/168) Gram-negative. Staphylococcus aureus was the most frequently detected species of Gram-positive bacteria (58.1%, 75/129) and the most frequently detected pathogen (44.6%, 75/168) in this study. The resistance of Gram-positive bacteria to peptides and oxazolidinones was low (less than 10%). Multivariate logistic regression analysis showed that age ≥45 years ( OR=6.991, 95% CI: 3.525 to 13.865, P<0.001), essential hypertension ( OR=4.191, 95% CI: 2.070 to 8.485, P<0.001), trauma ( OR=4.232, 95% CI: 2.409 to 7.435, P<0.001) and length of hospital stay ( OR=1.015, 95% CI: 1.001 to 1.029, P=0.030) were the risk factors for MDRO infection in patients with chronic osteomyelitis. Conclusions:The detection rate of MDRO is at a medium to high level. Gram positive bacteria are the main pathogens and resistant to most antibiotics. Antibiotic therapy guided by bacterial culture is of great significance for patients with chronic osteomyelitis. Age≥45 years, essential hypertension, trauma, and long hospital stay are risk factors for MDRO infection in patients with chronic osteomyelitis.