Objective:Periprosthetic joint infection (PJI) is one of the most severe complications following hip and knee arthroplasty and is a leading cause of revision surgery. Pathogens and their antibiotic susceptibility are key factors in the successful treatment of PJI. This study retrospectively analyzes the pathogen characteristics and antimicrobial susceptibility of PJI patients treated at our center, aiming to establish an empirical antibiotic regimen for PJI in the region, providing a reference for empirical antibiotic therapy in the clinical management of PJI.Methods:This study retrospectively reviewed PJI patients treated at our center from January 2018 to October 2024. In each case, preoperative arthrocentesis fluid, and synovium tissue from at least three sites during surgery were collected for aerobic and anaerobic blood culture. The positive culture rate, distribution of pathogens based on Gram staining, methicillin resistance, mixed infections, and multidrug resistance were analyzed. Effective coverage parameters were constructed based on antimicrobial sensitivity and coverage rates, and appropriate empirical antimicrobial regimens were proposed.Results:A total of 233 PJI patients were included in the analysis. There were 99 males and 134 females with an average age of 67.0±10.1 years (ranging from 32 to 93 years). The study included 130 hip and 103 knee arthroplasty patients. Among the patients, 202 (86.7%) had positive cultures, with a total of 301 pathogen strains isolated: 268 Gram-positive bacteria (89.4%), 25 Gram-negative bacteria (8.3%), and 7 fungal strains (2.3%). The most common Gram-positive bacteria were coagulase-negative staphylococci (196 strains, 65.1%), epidermal staphylococci (77 strains, 25.6%), Staphylococcus aureus (39 strains, 13.0%), and Streptococcus spp. (19 strains, 6.3%). The most common Gram-negative bacteria were Enterobacteriaceae (14 strains, 4.7%). In hip joint infections, the most prevalent pathogens were epidermal Staphylococci (48 strains, 28.1%) and Staphylococcus aureus (27 strains, 15.8%), while in knee joint infections, epidermal Staphylococci (29 strains, 22.3%) were most common. Regarding antibiotic resistance, 48.5% of staphylococcal strains were methicillin-resistant Staphylococcus, and 51.5% were multidrug-resistant strains. Staphylococci were 100% susceptible to vancomycin, teicoplanin, daptomycin, linezolid, and tigecycline, but exhibited high resistance to β-lactams and quinolone antibiotics. Analysis of empirical antibiotic regimens revealed that vancomycin combined with meropenem, linezolid combined with meropenem, vancomycin combined with imipenem, vancomycin combined with piperacillin/tazobactam, and vancomycin combined with ceftriaxone had effective coverage rates of 97.0%, 97.0%, 96.0%, 94.9%, and 90.9%, respectively.Conclusion:The main pathogens in PJI in this region are Gram-positive bacteria, with high rates of methicillin resistance and multidrug resistance. Based on antimicrobial susceptibility data, we recommend vancomycin combined with meropenem as the empirical treatment regimen for culture-negative PJI in this region, with linezolid combined with meropenem as an alternative.

Objective:Periprosthetic joint infection (PJI) is one of the most severe complications following hip and knee arthroplasty and is a leading cause of revision surgery. Pathogens and their antibiotic susceptibility are key factors in the successful treatment of PJI. This study retrospectively analyzes the pathogen characteristics and antimicrobial susceptibility of PJI patients treated at our center, aiming to establish an empirical antibiotic regimen for PJI in the region, providing a reference for empirical antibiotic therapy in the clinical management of PJI.Methods:This study retrospectively reviewed PJI patients treated at our center from January 2018 to October 2024. In each case, preoperative arthrocentesis fluid, and synovium tissue from at least three sites during surgery were collected for aerobic and anaerobic blood culture. The positive culture rate, distribution of pathogens based on Gram staining, methicillin resistance, mixed infections, and multidrug resistance were analyzed. Effective coverage parameters were constructed based on antimicrobial sensitivity and coverage rates, and appropriate empirical antimicrobial regimens were proposed.Results:A total of 233 PJI patients were included in the analysis. There were 99 males and 134 females with an average age of 67.0±10.1 years (ranging from 32 to 93 years). The study included 130 hip and 103 knee arthroplasty patients. Among the patients, 202 (86.7%) had positive cultures, with a total of 301 pathogen strains isolated: 268 Gram-positive bacteria (89.4%), 25 Gram-negative bacteria (8.3%), and 7 fungal strains (2.3%). The most common Gram-positive bacteria were coagulase-negative staphylococci (196 strains, 65.1%), epidermal staphylococci (77 strains, 25.6%), Staphylococcus aureus (39 strains, 13.0%), and Streptococcus spp. (19 strains, 6.3%). The most common Gram-negative bacteria were Enterobacteriaceae (14 strains, 4.7%). In hip joint infections, the most prevalent pathogens were epidermal Staphylococci (48 strains, 28.1%) and Staphylococcus aureus (27 strains, 15.8%), while in knee joint infections, epidermal Staphylococci (29 strains, 22.3%) were most common. Regarding antibiotic resistance, 48.5% of staphylococcal strains were methicillin-resistant Staphylococcus, and 51.5% were multidrug-resistant strains. Staphylococci were 100% susceptible to vancomycin, teicoplanin, daptomycin, linezolid, and tigecycline, but exhibited high resistance to β-lactams and quinolone antibiotics. Analysis of empirical antibiotic regimens revealed that vancomycin combined with meropenem, linezolid combined with meropenem, vancomycin combined with imipenem, vancomycin combined with piperacillin/tazobactam, and vancomycin combined with ceftriaxone had effective coverage rates of 97.0%, 97.0%, 96.0%, 94.9%, and 90.9%, respectively.Conclusion:The main pathogens in PJI in this region are Gram-positive bacteria, with high rates of methicillin resistance and multidrug resistance. Based on antimicrobial susceptibility data, we recommend vancomycin combined with meropenem as the empirical treatment regimen for culture-negative PJI in this region, with linezolid combined with meropenem as an alternative.