An Epidemiological Study Of Pathogenic Strains Of Post-traumatic Osteomyelitis In Multi-center And Their Drug Resistance

Objective:(1)Post-traumatic osteomyelitis of limbs is a common complication.At present,the clinical epidemiological data of post-traumatic osteomyelitis of limbs in China only rely on single center reports,there are no comprehensive studies describing the entire spectrum about it.We attempt to analyze the clinical epidemiological data of post-traumatic osteomyelitis of limbs in China,to identify susceptible populations,injury factors,main infected sites,complications and other risk factors,screening main pathogenic bacteria which caused post-traumatic osteomyelitis and analyzing its dynamic change of drug sensitive rate,drug resistance rate to antibiotics.We aims at providing the data of evidence-based medicine basis for the prevention and treatment of post-traumatic osteomyelitis of limbs in China.Methods:(1)We conducted a retrospective analysis of limb fracture patients across 21 China medical centers who with completed Electronic Health Record(EHR)data between 1 January 2008 and 31 December 2017.Analyzing the basic information of infection rate,susceptible populations,injury factors,infected sites,main complications and main pathogenic bacteria of post-traumatic osteomyslitis in different regions.(2)According to the types and quantity of pathogenic bacteria which caused post-traumatic osteomyelitis,identifying the relative risk factors for different infected populations(i.e.MI,PI,MP,MN,PP,PN,PP+PN).(3)Identifying the main comorbidities of patients with post-traumatic osteomyelitis in the limbs.According to the results of the main pathogenic bacteria and bacterial drug susceptibility tests,analyzing whether there is significant difference in the distribution of pathogenic bacteria and its drug sensitive rate,drug resistance rate in patients with and without comorbidities after post-traumatic osteomyelitis in the limbs.(4)To observe the dynamic changes of gram negative and gram positive bacteria which caused bone infection since January 1,2008 to December 31,2017,analyzing the dynamic changes of the main pathogenic bacteria which have been screened out during the ten years and the change trend of effect relationship of drug sensitive rate and drug resistance rate to antibiotics the main pathogenic bacteria over time.Results:(1)212,394 limb fractures patients with completed Electronic Health Record(EHR)data were screened across 21 hospitals between 1 January2008 and 31 December 2017,we enrolled 3526 patients who withpost-traumatic osteomyelitis.The overall infection rate gradually increased during past decade,and it was nearly 2% in 2017。(2)The epidemiological information of all 3526 patients shows that the patients mainly focus on male(80.0%).The age of all infected patients mainly focused on middle age,the mean of age was 42.2 years(95%confidence interval [%95 CI],26.2 to 58.2 years).The percentage of open fracture is 67.4%,it is significant higher than closed fracture(P<0.05).The patients who were transferred from other hospital without surgery is 48.4%(P<0.05).Left side of tibia and fibula,femur and calcaneus are more susceptible to occur traumatic bone infection than right side(P<0.05),left lower extremity is more susceptible to occur traumatic osteomyelitis than other anatomical sites(P<0.05).Traffic accident is the most dominant injury factor,no matter in all seven regions or the overall group.3526 patients were consisted of 2912 cases of MI(82.6%)and 614 cases of PI(14.7%),the proportion of gram-positive and negative bacteria in MI was approximately 1:1(49%:51%),and the proportion in PI was 30.7%:69.3%.We screen out four kinds of dominant gram positive bacteria and five kinds of dominant gram negative bacteria,respectively.MSSA(Methicillin-sensitive Staphylococcus aureus)is the most dominant Gram-positive pathogenic strains,there are 720 strains(38.8%).Pseudomonas aeruginosa is the most Gram-negative bacteria,there are 478strains(19.4%).(3)There are seven kinds of univariate risk factors for MI,PI,MP,MN,PP,PN and PP+PN.The Hui nationality is high risk factor for PI(odds ratio,2.865;95% CI,1.677 to 4.894;p=0.0001).Fall damage is risk injury factor for MI compared with traffic accident(odds ratio,0.647;95%CI,0.488 to 0.858;P=0.0025),the patients who are older than 30 years are susceptible to develop MI compared with those who are younger than 20 years.The patients who were transferred this department postoperative are susceptible to develop PI(odds ratio,2.675;95% CI,2.072 to 3.452),while those who return to follow-up in this department postoperative are more susceptible to develop MI(odds ratio,0.724;95% CI,0.472 to 2.347;P=0.0001).Opened fracture is risk factor for PI(odds ratio,0.955;95% CI,0.627 to 1.455;P<0.0001).Patients who with anemia,hypoproteinemia,multiple fracture,shock,and vascular injury are more susceptible to develop PI than those who without all above complications.Those who with diabetes,hypertension,and without any complications are more susceptible to develop MI.(4)There were nine major complications for all.MSSA is mainly resistance to Ampicillin and Penicillin,while it is mainly sensitive to Amoxicillin,Ciprofloxacin,Dalfopristin,Gentamicin,Levofloxacin,Linezolid,Moxifloxacin,Piperacillin,Rifampicin,SMZCo,Teicoplanin,Tetracycline,Tigecycline,Vancomycin.MRSA is mainly resistance Amoxicillin,Ampicillin,Azithromycin,Erycin,Lincomycin and Penicillin.It is sensitive to mainly sensitive to Dalfopristin,Linezolid,SMZCo,Teicoplanin,Tigecycline and Vancomycin.Pseudomonas Aeruginosa is mainly resistance to Amoxicillin,Ampicillin,Ampicillin/Sulbactam,Cefazolin,Cefotaxime,Cefotetan,Ceftriaxone,Cefuroxime and SMZCo.It is sensitive to Amikacin,Ciprofloxacin,Gentamicin,Levofloxacin,Piperacillin/Tazobactam,Tobramycin。Enterobacter Cloacae is mainly resistance to Amoxicillin,Ampicillin,Ampicillin/Sulbactam,Cefazolin,Cefotetan and Cefuroxime.It is sensitive to Amikacin,Cefepime,Cefoperazone/ Sulbactam,Ciprofloxacin,Ertapenem,Levofloxacin,Piperacillin/Tazobactam.(5)There were 4318 pathogens which caused post-traumatic osteomyelitis.Since 2008 to 2017,the overall numbers of strains of each year increased,Gram-negative bacteria(2460 strains,56.97%)was much more than Gram-positive bacteria,S.aureus was the most commonly involved pathogen(720 strains,16.67%).(6)MSSA were highly sensitive to Piperacillin,Quinolone,Polypeptide,Teicoplanin,Rifampicin,Dalfopristin and Linezolid,while the sensitivity of MSSA to Quinolone(Moxifloxacin and Ciprofloxacin),Amoxicillin,Vancomycin,Linezolid and SMZCo present a declining trend from 2008 to 2017(P<0.05).MRSA strains were highly sensitive to Polypeptide,Teicoplanin,Dalfopristin and Linezolid,while the sensitivity of MRSA to Quinolone,parts of ?-lactamase,Tigecycline,Gentamicin,Teicoplanin,Rifampicin and Linezolid present an increased trend(P<0.05).Pseudomonas Aeruginosa strains were highly sensitive to Aminoglycosides and Quinolone,while the sensitivity of Pseudomonas Aeruginosa to Cefperazone-Sulbactam and present an increasing trend(P<0.05).Acinetobacter Baumannii were low-sensitive to Amikacin and Ertapenem,and the drug sensitive rate of Acinetobacter Baumannii to most of?-lactamase and Quinolone still present a declining trend(P<0.05).Conclusions:(1)Post-traumatic osteomyelitis mainly focuses on male,middle age,open fracture,left lower extremities and who was transferred from other hospital without surgery.Traffic accident was the dominant injury factor.Some factors regard as risk factors for MI or PI.(2)Gram-negative bacteria are the main pathogens,both of MI and PI group.S.aureus is the dominant strain.Different complications may affect strains’ antimicrobial resistance/sensitive rate.(3)The drug resistance/sensitive rate of dominant pathogens were partly changed dynamically.