[Distribution and drug resistance of pathogens of blood stream infection in patients with hematological malignancies after chemotherapy]

[A single-center analysis of pathogenic bacteria distribution and drug resistance in bacterial bloodstream infections among patients with hematological diseases]

Objective: To analyze the distribution and drug resistance of pathogens of bacterial bloodstream infection in patients with hematological diseases in the Department of Hematology of Tianjin Medical University General Hospital, and to provide etiological data for clinical empirical anti-infection treatment. Methods: A retrospective analysis was conducted on the general clinical information, pathogenic bacteria and drug susceptibility test results of patients with hematological diseases diagnosed with bacterial bloodstream infection by menstrual blood culture in our center from January 2016 to December 2022. Results: Patients included 498 inpatients, with a total of 639 bacterial strains. Among the patients, 86.9% patients had malignancies, and 76.7% had agranulocytosis. Symptoms of concurrent infections, including those of the respiratory tract, oral mucosa, skin and soft tissues, and abdominal sources were observed in 68.3% patients. Gram-negative bacteria (G(-)) accounted for 79.0% of the isolated bacteria, and gram-positive bacteria (G(+)) accounted for 21.0%. The top five isolated pathogens were Klebsiella pneumoniae (22.5%), Escherichia coli (20.8%), Pseudomonas aeruginosa (15.0%), Enterococcus faecium (5.5%), and Stenotrophomonas maltophilum (5.0%). Escherichia coli exhibited a decreasing trend of resistance to quinolones, cephalosporins, and carbapenems. Klebsiella pneumoniae exhibited increasing rates of resistance to quinolones and cephalosporins between 2016 and 2018, but the rated decreased after 2019. The resistance rate to carbapenems exhibited by Pseudomonas aeruginosa was approximately 20%. Carbapenem-resistant strains of Pseudomonas aeruginosa strains were first detected in 2017, with a peak resistance rate of 35.7%, detected in 2019. A 60.0% resistance rate to methicillin was observed in methicillin-resistant coagulase-negative staphylococci (MRCNS), and one case of linezolid-resistant MRCNS was detected. Conclusions: Pathogenic bacteria of bacterial bloodstream infections were widely distributed in our center, and precautions are warranted against carbapenem resistant P. aeruginosa and Klebsiella pneumoniae.

Integrative analysis of multi-omics data reveals inhibition of RB1 signaling promotes apatinib resistance of hepatocellular carcinoma

Although apatinib is a promising drug for the treatment of liver cancer, the underlying drug resistance mechanism is still unclear. Here, we constructed apatinib-resistant HepG2 cells. We then characterized the epigenomic, transcriptomic, and proteomic landscapes both in apatinib-resistant and non-resistant HepG2 cells. Differential expression, ATAC-seq, and proteomic data analyses were performed. We found that the cell cycle related protein RB1 may play an essential role in the process of apatinib resistant to hepatocarcinoma. Moreover, there were extensive variations at the transcriptome, epigenetic, and proteomic level. Finally, quantitative PCR (qPCR) and western blot analysis showed that expression level of RB1 in apatinib-resistant cell as well as the samples of patients in progressive disease were significantly lower than that in controls. Those results also showed that the RB1 pathway inhibitors CDK2-IN-73 and Palbociclib could relieve the resistance of apatinib resistant cells. Our results further enhance our understanding of the anti-tumorigenic and anti-angiogenic efficacy of apatinib in liver cancer and provide a novel perspective regarding apatinib resistance. Furthermore, we proved that CDKN2B inhibition of RB1 signaling promoted apatinib resistance in hepatocellular carcinoma. Those findings have greatly important biological significance for the resistance of apatinib and the treatment of liver cancer.

[Active screening of intestinal carbapenem-resistant Enterobacteriaceae in high-risk patients admitted to the hematology wards and its effect evaluation]

Objective: To evaluate the effect of intestinal carbapenem-resistant Enterobacteriaceae (CRE) active screening combined with enhanced intervention in the prevention and control of nosocomial infection in patients admitted to the hematological ward. Methods: Patients who were admitted to the Department of Hematology in a tertiary-care general hospital from March 1, 2017 to December 31, 2019 and underwent chemotherapy or immunosuppressive therapy comprised the intervention group. They were screened for intestinal CRE at least thrice. From December 1, 2016 to February 28, 2017, patients who underwent chemotherapy or immunosuppressive therapy without active intestinal CRE screening in the Department of Hematology formed the control group. Both the patient groups were monitored for CRE infection in real time. The χ(2) test was used to compare the changes in the CRE infection rate and mortality in high-risk patients before and after the active screening. Results: During the intervention period, the CRE colonization rate of patients was 16.46% (66/401) ; in terms of disease distribution, the colonization rate of acute leukemia was the highest 23.03% (26/113) . Of the 66 colonized patients, 27 (40.9%) patients were identified as positive for CRE at the first screening, 15 (22.7%) were identified at the time of the second screening, and the remaining 24 (36.4%) were identified at the third or subsequent screening; Carbapenem-resistant Klebsiella pneumoniae (CRPK) strains were dominant among the pathogens, accounting for 54.55% (36/66) . During the active screening period, the CRE infection rate (2.49%) and mortality rate (50.00%) of high-risk patients were significantly lower than those of the controls (11.30% and 69.23%, respectively) . The pathogens of 10 CRE infection patients during the intervention period were exactly the same as the previous active screening pathogens, and the coincidence rate was 100%. Conclusion: The CRE colonization rate was the highest in patients with acute leukemia who were admitted in the hematology wards. CRPK is the main pathogen of CRE colonization, infection, and death. Increasing the frequency of screening can significantly raise the positive rate of screening, Active screening can effectively reduce the incidence and subsequent mortality of CRE in high-risk patients admitted in the hematological wards. High coincidence rate between CRE screening positive pathogens and subsequent CRE infection pathogens. Intestinal CRE screening can serve as an indicator of CRE bloodstream infection in patients with hematological diseases as well as provide information for antibiotics therapy.

[A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in adult patients with hematological disease during the period 2014-2018]

Objective: To investigate the distribution of pathogens and the antibiotic resistance profile of bloodstream infections in adult patients with hematological diseases in the period 2014-2018 to provide evidence for the rational use of antibiotics. Methods: We retrospectively analyzed the bloodstream infections in patients with hematological diseases from January 2014 to December 2018 at the institute of Hematology & Blood Diseases Hospital; this included an assessment of the clinical characteristics, distribution of pathogens, and antibiotic resistance data. Results: There were 1935 episodes of BSIs in the 1478 patients who were studied; among these, 1700 episodes occurred in the neutropenic phase. The 7-day and 30-day all-cause mortality rates were 5.5% and 8.2%, respectively. Bloodstream infection was usually accompanied by respiratory tract, perianal zone mucositis, and digestive tract symptoms; the respective proportions were 12.4%, 12.3%, and 9.1%, respectively. Total 2025 strains were isolated; 1551 (76.6%) of the pathogens were gram-negative bacteria, mainly Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa; 423 (20.9%) were gram-positive bacteria, mainly Staphylococcus spp. and Streptococcus spp. Viridans; 51 (2.5%) were fungi, mainly Candida tropicalis. The resistance rates of Enterobateriaceae to piperacillin/tazobactam, carbapenems, amikacin were <10%. The resistance rates of K. pneumoniae to cefepime, piperacillin/tazobactam and meropenem increased annually. The resistance rates of Pseudomonas aeruginosa to piperacillin/tazobactam, quinolones, Aminoglycosides were <5% even when compared to carbapenems. Eleven stains of methicillin-resistant S. aureus and 1 stain of vancomycin-resistant Enterococcus faecium were detected. Conclusion: The pathogens of bloodstream infection in adult patients with hematological diseases are widely distributed. The resistance rates of different strains vary; the rates in some species had a tendency to increase. Antibiotics should be selected rationally as per the distribution of pathogens and resistance to antibiotics in different patient groups.

[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.