The occurrence and abundance of antibiotic resistance genes in rivers of tropical islands: a case of Hainan Island, China.

In this study, the occurrence and distribution of 49 antibiotic resistance genes (ARGs) and two integrase genes (intl1, intl2) in three major rivers of Hainan Island, China, were investigated in July 2021, and to explore the spatial distribution of the target genes in the three rivers with the potential influencing factors such as regional characteristics and environmental factors. The results showed that a total of 46 ARGs and two integrase genes were detected in water and sediment, and the absolute abundance of ARGs ranged from 1.16 × 103 to 2.97 × 107 copies/L and 3.34 × 103-1.55 × 107 copies/g. ARGs of macrolides, aminoglycosides, and sulfonamides were this study's main types of ARGs. The aadA2, tetE, ermF, tetX, aac(6')-Ib, tetW, and qnrS genes are predominant ARGs in the water and sediment of the three rivers. The relative abundance of ARGs shows higher abundance in the midstream and downstream and lower abundance in the upstream and estuarine. After conducting a correlation analysis, it was found that there was a significant positive correlation between the ARGs detected in the water of the three main rivers. However, in sediment, tetC was negatively correlated with tetQ, macB was negatively correlated with ermF and ereA (p < 0.05), while the remaining ARGs showed positive correlations. Specifically, there was no significant positive correlation between tetQ and tetC, macB and ereA, and ermF in the sediments. Among the nine environmental factors studied, pH was found to be the main factor associated with the occurrence of ARGs in the aquatic environment, but it was also significantly associated with only nine ARGs. Among the detected heavy metals, only Cd and Zn showed significant correlations with the two ARGs in the water bodies of the three main rivers. It indicated that the pollution of ARGs in the three major rivers was in the initial stage, the detection abundance was low, the influence of environmental factors was small, and the interaction between ARGs seemed to be the main driving force. This study provides a scientific basis for further understanding the occurrence of ARGs and their influencing factors in a tropical island environment, and lays a foundation for subsequent management.

[Correlation between U2AF1 Gene Mutation Characteristics and Clinical Manifestations and Prognosis in Patients with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the correlation between U2AF1 gene mutation and clinical manifestations and prognosis in patients with myelodysplastic syndromes (MDS). METHODS: The clinical data of 203 MDS patients who accepted Next Generation Sequencing (NGS) was retrospectively analyzed in Nanfang Hospital, Southern Medical University from December 2012 to October 2019. According to whether the patients had U2AF1 gene mutation, the patients were divided into U2AF1 mutated group and non-mutated group, and the relationship between gene mutation characteristics and clinical manifestations and prognosis was analyzed. Then according to the difference of the mutation site of U2AF1, the patients in U2AF1 mutated group were divided into U2AF1S34 mutated group and U2AF1Q157/R156 mutated group, and the correlation between gene mutation characteristics and prognosis was analyzed. RESULTS: The incidence of U2AF1 mutation in MDS patients was approximately 11.3% (23/203), and the mutation frequency of U2AF1 allele was 32.5%. The male ratio in U2AF1 mutated group was significantly higher than that in U2AF1 non-mutated group (P=0.001). There was no patient who had complex karyotypes or TP53 gene mutation in U2AF1 mutated group. There were no significant differences in ages, blood parameters, bone marrow blasts, WHO 2016 classification, IPSS-R category, chromosomal abnormalities like del(5q), -7/del(7q), del(20q), +8, and gene mutation like ASXL1, DNMT3A, RUNX1, SF3B1, and SRSF2 mutation between U2AF1 mutated group and the non-mutated group. Compared with the non-mutated group, there was no significant difference in the overall survival time (P=0.377), the time of acute myeloid leukemia (AML) transformation (P=0.681), and the response rate to hypome- thylating agents in U2AF1 mutated group (P=0.556). Besides, no differences were observed in sex, diagnosis age, WHO 2016 classification, IPSS-R category, blood parameters, overall survival time, and AML transformation time between U2AF1S34 mutated group and U2AF1Q157/R156 mutated group. CONCLUSION: The U2AF1 gene mutation dose not affect the survival time, AML transformation time, and response rate to hypomethylating agents in MDS patients. Besides, there are no statistical differences in the clinical characteristics and prognosis of MDS patients between U2AF1S34 mutated group and U2AF1Q157/R156 mutated group. Transplantation shows no significant benefit for patients with U2AF1 mutation.

[Clinical characteristics of hemophagocytic syndrome: analysis of 46 cases].

OBJECTIVE: To analyze the clinical manifestations, laboratory findings, treatment and prognosis of patients with hemophagocytic syndrome (HPS). METHODS: A retrospective study was carried out to analyze the underlying disease, clinical characteristics, laboratory findings and outcomes of 46 patients with HPS. RESULTS: This cohort included 19 cases of HPS secondary to cancer, 11 cases of HPS secondary to infection, 10 cases of suspected malignant lymphoma based on PET-CT findings (without biopsy), and 6 cases of unknown etiology. The coincidence rate of the clinical characteristics of the patients with the indices listed in HPS-2004 criteria were: fever (100%), elevated serum ferritin (100%), cytopenias (93.48%), splenomegaly (91.30%), hemophagocytosis in the bone marrow, spleen or lymph nodes (84.78%), hypofibrinogenemia (67.39%), and hypertriglyceridemia (54.05%). The cases of cancer, infections and unknown etiology showed significant differences in serum levels of ferritin and ß2MG (P<0.05), and significant differences were found in triglycerides, LDH, and fibrinogenemia between the nonfatal and fatal cases (P<0.05). CONCLUSION: HPS can be secondary to various underlying diseases, many associated with Epstein-Barr virus infection. Cancer, especially NK/T-cell lymphoma, is the main cause of HPS. Persistent fever, elevated serum ferritin level and cytopenias are the most sensitive indicators for diagnosis of HPS, and early diagnosis and treatment are critical to lower the mortality rate of this disease.