[Distribution and Drug Sensitivity Analysis of Pathogenic Bacteria Isolated from Patients in Hematology Department].

OBJECTIVE: To investigate the distribution and drug sensitivity of pathogenic bacteria isolated from patients in hematology department, in order to provide evidence for rational use of antibiotics in clinic. METHODS: The distribution of pathogenic bacteria and drug sensitivity data of patients in the hematology department of The First Affiliated Hospital of Nanjing Medical University from 2015 to 2020 were retrospectively analyzed, and the pathogens isolated from different specimen types were compared. RESULTS: A total of 2 029 strains of pathogenic bacteria were isolated from 1 501 patients in the hematology department from 2015 to 2020, and 62.2% of which were Gram-negative bacilli, mainly Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii. Gram-positive coccus accounted for 18.8%, mainly Coagulase-negative staphylococcus (CoNS) and Staphylococcus aureus. Fungi (17.4%) were mainly candida. The 2 029 strains were mainly isolated from respiratory tract (35.1%), blood (31.8%) and urine (19.2%) specimens. Gram-negative bacilli were the main pathogenic bacteria in different specimen types (>60%). K. pneumoniae, S. maltophilia and A. baumannii were the most common pathogens in respiratory specimens, E. coli, CoNS, K. pneumoniae and P. aeruginosa were common in blood samples, and E. coli and Enterococcus were most common in urine samples. Enterobacteriaceae had the highest susceptibility to amikacin and carbapenems (>90.0%), followed by piperacillin/tazobactam. P. aeruginosa strains had high sensitivity to antibiotics except aztreonam (<50.0%). The susceptibility of A. baumannii to multiple antibiotics was less than 70.0%. The antimicrobial resistance rates of E. coli and K. pneumoniae in respiratory tract specimens were higher than those in blood specimens and urine specimens. CONCLUSION: Gram-negative bacilli are the main pathogenic bacteria isolated from patients in hematology department. The distribution of pathogens is different in different types of specimens, and the sensitivity of each strain to antibiotics is different. The rational use of antibiotics should be based on different parts of infection to prevent the occurrence of drug resistance.

Liquid biopsy for non-invasive assessment of liver injury in hepatitis B patients.

BACKGROUND: Hepatitis B is a major public health problem in China. Accurate liver injury assessment is essential for clinical evidence-based treatment. Liver biopsy is considered the gold standard method to stage liver disease, but it is not widely used in resource-limited settings. Therefore, non-invasive liquid biopsy tests are needed. AIM: To assess liver injury in hepatitis B patients using quantified cell free DNA combined with other serum biomarker as a liquid biopsy-based method. METHODS: A cohort of 663 subjects including 313 hepatitis B patients and 350 healthy controls were enrolled. Ultrasound-guided liver biopsies followed by histopathological assessments were performed for the 263 chronic hepatitis B patients to determine the degree of liver injury. Cell-free DNA was quantified using a novel duplex real-time polymerase chain reaction assay. RESULTS: Compared with healthy controls, patients with hepatitis B virus (HBV) infection had significantly higher plasma DNA, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and HBV DNA levels (P < 0.01). Serum ALT, AST, bilirubin, and plasma DNA levels of patients with marked-severe inflammation were significantly higher than those with mild-moderate inflammation (P < 0.01). There was a statistically significant correlation between hepatocyte inflammation severity and serum bilirubin (R 2 = 0.673, P < 0.01) or plasma DNA (R 2 = 0.597, P < 0.01) levels. The areas under the curves of serum ALT, bilirubin, plasma DNA, and their combination to distinguish between patients with mild-moderate and marked-severe inflammation were 0.8059, 0.7910, 0.7921, and 0.9564, respectively. CONCLUSION: The combination of plasma DNA, serum ALT, and bilirubin could be a candidate liquid biopsy for non-invasive assessment of liver injury in hepatitis B patients.

[Dynamic monitoring of plasma circulating DNA in patients with acute myeloid leukemia and its clinical significance].

This study was aimed to quantify plasma circulating DNA level in patients with acute myeloid leukemia (AML) and to evaluate its clinical significance. 66 AML patients and 100 controls (60 healthy subjects for health examination, 20 cases of benign hematopathy, and 20 cases of solid tumors) were enrolled in this study. Blood samples were collected from AML patients at different status of disease and control groups. Circulating DNA were drew by using the BILATEST DNA Kit. The level of plasma DNA was determined by using duplex real-time quantitative PCR. The results showed that the median value of plasma DNA level in AML patients at diagnosis was 168.5 (73.4 - 245.1) ng/ml, significantly higher than those in three control groups, and the median level in male patients was significantly higher than that in female patients (P = 0.019). No significant difference was found in plasma DNA level of the patients at different ages and with different FAB subtypes. Compared with level before chemotherapy, the plasma DNA levels in complete remission patients and partial remission patients decreased significantly, and with no statistical difference from level of healthy controls, but was significantly different from level of non-remission patients (P < 0.05). Following up of 31 remission patients showed that the plasma DNA level increased in 5 out of 6 (83.3%) relapsed patients, but no increase was found in 22 out of 25 (88.0%) non-relapsed patients. It is concluded that the quantification of plasma DNA may be useful for evaluating therapeutic effects and monitoring relapse in AML patients.

[Study of quantitative detection of circulating DNA in the plasma of patients with cervical lesion].

OBJECTIVE: To quantitatively detect circulating DNA levels in the plasma of patients withcervical lesion and to determine the value for diagnosis of cervical lesion and cervical cancer. METHODS: Preoperative blood samples were collected from 53 cases of low-grade lesions, 49 cases of high-grade lesions, 44 cases of cervical invasive cancer and 70 cases of healthy women. Plasma DNA was extracted by magnetic bead method (BILATEST DNA kit). The quantity of plasma DNA was determined by duplex real-time quantitative PCR. RESULTS: Median plasma DNA level of invasive cervical cancer patients was 61.59 mg/L (32.06-162.16 mg/L), which was significantly higher than that of healthy women [16.35 mg/L (11.98-22.71 mg/L), P<0.01]. Among invasive cervical cancer patients, median plasma DNA level of squamous carcinoma patients was slightly higher than that of adenocarcinoma (50.43 versus 47.31 mg/L, P>0.05). Median plasma DNA level of stage I patients was lower than that of stage II-III patients (46.02 versus 71.35 mg/L, P<0.05). CONCLUSION: Quantitatively detecting plasma circulating DNA may be with some application prospect in the diagnosis of cervical diseases.

[The level of peripheral circular DNA in patients with hand foot and mouth disease].

OBJECTIVE: To determine the circular DNA level of patients with hand foot and mouth disease (HFMD) and evaluate its potential clinical value. METHODS: Venous blood in 30 healthy children and 78 patients with HFMD within 3 days of onset of illness and convalescent period was collected. The level of plasma circular DNA was detected by duplex real-time polymerase chain reaction assay. Blood sugar, high-sensitive CRP(hs-CRP) and leucocyte were also detected. RESULTS: The level of circular DNA in control group was (6.57 +/- 4.67) ng/ml. The level of circular DNA in ordinary and severe HFMD patients was (11.51 +/- 7.75) ng/ml and (20.59 +/- 10.67) ng/ml before treatment, respectively. The levels of circular DNA in ordinary and severe HFMD patients were significantly higher than that in control group (P = 0.021; 0.000); the level of circular DNA in severe HFMD patients was significantly higher than that in ordinary HFMD patients (P = 0.011). The level of circular DNA in severe HFMD patients after treatment were significantly lower than that before treatment (P = 0.033). The level of circular DNA before treatment and after treatment in ordinary HFMD patients had no significant difference. The levels of blood sugar and hs-CRP in severe HFMD patients were higher than those in ordinary before treatment (P = 0.045; 0.011). The levels of blood sugar and hs-CRP before treatment and after treatment in ordinary HFMD patients had no significant change. There was significantly positive correlation between the level of circular DNA and that of hs-CRP in HFMD patient (P = 0.021), but there was no correlation between the level of circular DNA and that of blood sugar and leucocyte. CONCLUSIONS: The level of circular DNA not only become an early identification marker of severe HFMD patients, but also become monitoring marker of effect of treatment.