Hongmei Xu,1 Ningning Wu,2 Hui Yu,3 Chuanqing Wang,4 Jikui Deng,5 Hongmei Wang,5 Chunzhen Hua,6 Yinghu Chen,6 Xuejun Chen,7 Ting Zhang,8 Hong Zhang,9 Yiping Chen,10 Shifu Wang,11 Qing Cao,12 Huiling Deng,13 Sancheng Cao,14 Jianhua Hao,15 Wei Gao,16 Chunmei Jing2 1Infectious Disease Department, Children’s Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Chongqing, People’s Republic of China; 2Department of Clinical Laboratory, Children’s Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders; Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Child Rare Diseases in Infection and Immunity, Chongqing, People’s Republic of China; 3Infectious Disease Department, Children’s Hospital of Fudan University, National Children’s Medical Center, Shanghai, People’s Republic of China; 4Department of Clinical Microbiology Laboratory, Nosocomial Infection Control Department, Children’s Hospital of Fudan University, National Children’s Medical Center, Shanghai, People’s Republic of China; 5Infectious Disease Department, Shenzhen Children’s Hospital, Shenzhen, People’s Republic of China; 6Infectious Disease Department, Children’s Hospital of Zhejiang University, Zhejiang, People’s Republic of China; 7Department of Medical Laboratory, Children’s Hospital of Zhejiang University, Zhenjiang, People’s Republic of China; 8Digestive and Infectious Disease Department, Children’s Hospital of Shanghai Jiaotong University, Shanghai, People’s Republic of China; 9Department of Medical Laboratory, Children’s Hospital of Shanghai Jiaotong University, Shanghai, People’s Republic of China; 10Pediatric Infectious Disease Department, Second Affiliated Hospital, and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, People’s Republic of China; 11Department of Medical Laboratory, Qilu Children’s Hospital, Shandong University, Shandong, People’s Republic of China; 12Infectious Disease Department, Shanghai Children’s Medical Center, Shanghai, People’s Republic of China; 13Infectious Disease Department, Xi’an Children’s Hospital, Xi’an, People’s Republic of China; 14Department of Medical Laboratory, Xi’an Children’s Hospital, Xi’an, People’s Republic of China; 15Infectious Disease Department, Children’s Hospital of Kaifeng City, Kaifeng, People’s Republic of China; 16Department of Medical Laboratory, Children’s Hospital of Kaifeng City, Kaifeng, People’s Republic of ChinaCorrespondence: Chunmei Jing, Department of Clinical Laboratory, Children’s Hospital of Chongqing Medical University, Chongqing Medical University, No. 136 Zhongshan Er Road, Yu Zhong District, Chongqing, 400014, People’s Republic of China, Email jcm791203@163.comObjective: Aim to investigate the pathogens distribution and drug resistance of gram-negative bacteria causing bloodstream infection (BSIs) in Infectious Disease Surveillance of Pediatric from 2016 to 2022. The prevalence of four important drug resistance phenotypes was studied: difficult-to-treat resistance, fluoroquinolone resistance, carbapenem resistance, and extended-spectrum cephalosporin resistance, and to provide reference basis for preventing and treating BSIs diseases in children.Methods: Strain identification and antimicrobial susceptibility tests were independently performed at each hospital. Data were analyzed using Whonet 5.6 and GraphPad Prism 8 software. The Mann–Whitney U-test was used to examine and compare temporal changes.Results: A total of 39977 BSIs strains were isolated, with 27.1% of the negative bacteria causing BSIs (10824 strains). The highest bacteria detected were E. coli and S. maltophilia in the neonatal and pediatric groups. The detection rate of carbapenem-resistant-K. pneumoniae (CRKPN) in neonate group was 31.4%, significantly increased compared with pediatric group, whose detection rate was 24.7%. The rates of resistance to levofloxacin and trimethoprim/sulfamethoxazole were significantly lower in neonatal groups than pediatric groups in BSIs caused by K. pneumoniae. To imipenem and meropenem were 3.6% and 3.9% among neonatal isolates, which was lower than 4.7% and 5.8 among pediatric BSIs caused by E. coli. Isolated from neonatal BSIs caused by A. baumannii showed lower resistance ratios to all the agents tested than those from pediatric. However, only the prevalence of piperacillin/tazobactam resistance was statistically lower than that in pediatric BSIs caused by P. aeruginosa. The average detection rates of carbapenem resistance, extended-spectrum cephalosporin resistance, and fluoroquinolone resistance for K. pneumoniae and E. coli were 28.1%,41.4%,11.6% and 4.0%,24.3%,31.1%, respectively.Conclusion: The detection rate of gram-negative pathogens showed an increasing trend among the bloodstream infection. The detection rate of CRKPN assumed a downward trend in 2018. There are differences types of pathogens between the neonatal group and the pediatric group, The detection rate of CRKPN in the neonate group was significantly higher than pediatric group. The first average detection rates for carbapenem resistance, extended-spectrum cephalosporin resistance, and fluoroquinolone resistance were obtained for A. baumannii, K. pneumoniae, and Escherichia coli, respectively. Those data showed a high level of antimicrobial resistance, which has posed an urgent threat to Children’s health, suggested that effective monitoring of antimicrobial resistance and antimicrobial stewardship among children in China are required.Keywords: bloodstream infection, pathogenic bacterium, difficult-to-treat resistance, carbapenem resistance, extended-spectrum cephalosporin resistance, fluoroquinolone resistance