[Clinical and bacteriological analysis of lymphoid tissue neoplasms patients with bacteria bloodstream infections]

[Key microbial monitoring and clinical analysis of bloodstream infections and CRO colonization after hematopoietic stem cell transplantation in hematological patients]

Objective: To investigate the distribution and clinical characteristics of pathogenic bacteria following hematopoietic stem cell transplantation (HSCT), as well as to provide a preliminary research foundation for key microbial monitoring, and clinical diagnosis and treatment of infections after HSCT in hematological patients. Methods: We retrospectively analyzed the clinical data of 190 patients who tested positive for microbial testing [G-bacteria blood culture and/or carbapenem-resistant organism (CRO) screening of perianal swabs] at our center from January 2018 to December 2022. Patients were divided into blood culture positive, perianal swab positive, and double positive groups based on the testing results. The three patient groups underwent statistical analysis and comparison. Results: The top four pathogenic bacteria isolated from sixty-three patients with G-bacteria bloodstream infection (BSI) were Escherichia coli (28 strains, 43.75% ), Klebsiella pneumonia (26 strains, 40.63% ), Pseudomonas aeruginosa (3 strains, 4.69% ), and Enterobacter cloacae (3 strains, 4.69% ). The top three pathogenic bacteria isolated from 147 patients with CRO perianal colonization were carbapenem-resistant Klebsiella pneumoniae (58 strains, 32.58% ), carbapenem-resistant Escherichia coli (49 strains, 27.53% ), and carbapenem-resistant Enterobacter cloacae (20 strains, 11.24% ). The 3-year disease-free survival (DFS ) and overall survival (OS) of double positive group patients were significantly lower compared to those in the blood culture and perianal swab positive groups (DFS: 35.6% vs 53.7% vs 68.6%, P=0.001; OS: 44.4% vs 62.4% vs 76.9%, P<0.001), while non-relapse mortality (NRM) was significantly higher (50.0% vs 34.9% vs 10.6%, P<0.001). Failed engraftment of platelets and BSI are independent risk factors for NRM (P<0.001). Using polymyxin and/or ceftazidime-avibactam for more than 7 days is an independent protective factor for NRM (P=0.035) . Conclusion: This study suggests that the occurrence of BSI significantly increases the NRM after HSCT in patients with hematological diseases; CRO colonization into the bloodstream has a significant impact on the DFS and OS of HSCT patients.

[Perianal swabs surveillance cultures of Carbapenem-resistant Enterobacteriaceae(CRE) can be hints for CRE bloodstream infection in patients with hematological diseases]

Objective: To analyze the hints role of surveillance cultures of Carbapenem-resistant Enterobacteriaceae (CRE) by perianal swabs in patients with hematological diseases, and seek risk factors of CRE bloodstream infection. Methods: The resistance of CRE from 2 914 patients with hematological diseases who cultured perianal swabs, CRE bloodstream infection and risk factors were analyzed during January 2016 to December 2017. Results: In this study, perianal swabs from 2 914 patients with hematological diseases were cultured, 74 patients were CRE positive, and bloodstream infection with CRE was found in 13 of these patients. A total of 87 CRE strains were isolated (The same patient only keep the first one for the same location), including 31 Klebsiella pheuminiae, 43 Escherichia coli, 8 Enterobacter cloacae and 6 other Enterobacteriaceae. The resistance rates to piperacillin / tazobactam, imipenem, meropenam, amikacin, levofloxacin, tigecycline were 91.9%, 74.4%, 98.8%, 17.6%, 74.4% and 8.0%, respectively. Resistance to carbapenem, aminoglycoside, quinolones and tegacycline were highly consistent between two sites from 13 patients, whose both perianal swabs and blood were positive in CRE cultures. Febrile neutropenic time, digestive tract symptoms and perianal infection were independent risk factors for bloodstream infection in patients with perianal swabs positive results, the odds ratios (OR) were 1.10 (P=0.029), 1.13 (P=0.005) and 1.23 (P=0.016), respectively. Conclusion: Perianal swabs surveillance cultures of CRE can be hints for CRE bloodstream infection in patients with hematological diseases, and also can provide suggestions for antibiotics. Long time of febrile neutropenic, digestive tract symptoms and perianal infection can be the early warning for CRE bloodstream infections.