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Yiqun Liao,1 Junjie Gong,1 Xiaoliang Yuan,2 Hongfei Lu,1 Lixia Jiang1 1Department of Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China; 2Department of Respiratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzho, People’s Republic of ChinaCorrespondence: Yiqun Liao, Department of Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, 23 Qingnian Road, Zhanggong District, Ganzhou, 341000, Jiangxi Province, People’s Republic of China, Tel +86-15979704263, Email joanna_qun@163.comBackground: The global prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a serious challenge for nosocomial infection and attracted worldwide attention. This study explored the drug resistance genes and molecular characteristics for CRKP, providing a reference for nosocomial prevention and control.Methods: A total of 42 CRKP isolates were collected from the First Affiliated Hospital of Gannan Medical University (Ganzhou, China) from January 2018 to February 2021. The drug resistance of CRKP was tested by the VitekII Compact system. Drug resistance gene expression was detected by poly-merase chain reaction (PCR), and molecular typing was performed by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST).Results: All the 42 CRKP isolates were multi-drug resistant. Among them, 35 isolates (83.3%) produced blaKPC-2 and 12 isolates (28.6%) produced blaNDM-1. The detection rate of blaIMP-4 and blaOXA-48 was 2.4% (1/42), respectively. Twelve isolates (28.6%) carried both blaKPC-2 and blaNDM-1, one isolate (2.4%) carried both blaKPC-2 and blaIMP-4, and one isolate (2.4%) carried blaKPC-2, blaNDM-1 and blaOXA-48. A variety of other extended-spectrum beta-lactamases (ESBLs) were also detected. All 42 isolates carried blaSHV and blaCTX-M-1, 27 isolates (64.3%) carried blaTEM and 12 isolates (28.6%) carried blaCTX-M-9. The MLST data classified the 42 CRKP isolates into 11 sequence types, mainly ST11, accounting for 61.9% (26/42), of which 92.3% of isolates (24/26) carrying blaKPC-2. The PFGE results demonstrated that the 42 CRKP isolates could be divided into 20 clusters A-T, with cluster A (26.2%, 11/42) and cluster H (21.4%, 9/42) dominating, which were all ST11.Conclusion: The CRKP isolates were severely multi-drug resistant, and the main resistant gene was blaKPC-2 production, carrying multiple ESBLs genes simultaneously. The MLST and PFGE revealed that the ST11-blaKPC-2 Klebsiella pneumoniae was the main clonotype. Our findings may offer help to antibiotics selection and nosocomial infection prevention and control.Keywords: carbapenem-resistant Klebsiella pneumoniae, drug resistance genes, homology, molecular epidemiological characteristics

This research aims to improve the efficiency of phytoremediation of Cd in soil using sunflowers and optimizing the model of Cd uptake by plants. Five low molecular weight organic acids (LMWOAs), oxalic acid (OA), acetic acid (AA), tartaric acid (TA), malic acid (MA), and citric acid (CA) at 2, 4, and 6 mmol/kg, were applied to sunflowers at 20, 30, and 40 days after seed emergence. The pH, electric conductivity (EC), total nitrogen (TN), total phosphorus (TP), catalase activity, amylase activity, invertase activity, and Cd content in rhizosphere soil and Cd in plant tissues were analyzed. Plant biomass was greater at the application rates of 2 and 4 mmol/kg. For each acid treatment, the Cd content in roots and leaves increased, while that of the stem and bud decreased. The total Cd accumulation increased due to the increase in plant biomass, especially root tissues; LMWOAs applied at 20 or 30 days after seedling emergence achieved higher Cd accumulations by expanding the Cd absorption capacity of rhizosphere soil. Application time had a more significant influence on plant biomass, Cd content, and accumulation in plant tissues than the variation of LMWOAs. Soil invertase activity and pH are the main factors causing the change in Cd form. An improved Freundlich model, using soil EC and pH, had higher accuracy than a model using pH alone. LMWOAs can increase Cd accumulation in plants, and a lower application rate (2 mmol/kg) and earlier application date (20 days after seedling emergence) are beneficial for improving the phytoremediation efficiency of sunflower. The increase of root biomass expanded the contact area between plants and soil, which was one of the reasons for the increase of Cd accumulation. EC could be used as a supplementary index to improve the Freundlich model when using pH.

The height, number of tillers, chlorophyll (Chl) a and b content, and yield of rice (Oryza sativa L.) in response to alternating stresses of drought and waterlogging (ASDW) at the tillering...

The increasing soil salinity levels under reclaimed water irrigation have a negative effect on plant growth. Greenhouse experiments were conducted in 2018 and 2019 under reclaimed water–fresh water combined irrigation. After transplanting (Day 1), rice was irrigated with clean water (tap water) for 10 days to facilitate rice root colonisation. Subsequently, rice was irrigated with reclaimed water for 50 days (Day 11 to 60), and then irrigated with clean water. B. subtilis and S. cerevisiae were mixed with clean water (tap water) and irrigated into soil at Day 61. B. subtilis (20 billion colony-forming units/g) and S. cerevisiae (20 billion colony-forming units/g) were mixed at the following proportions: 5 g and 0 (J1), 3.75 g and 1.25 g (J2), 2.5 g and 2.5 g (J3), 1.25 g and 3.75 g (J4), and 0 and 5 g (J5), respectively, rice treated with reclaimed water (CK) and clean water (J0) with no microorganisms applied were also used. We measured NO3--N and NH4+-N concentrations and electrical conductivity (EC) in the soil at 0–5, 5–15, and 15–25 cm layers, root activity, and malondialdehyde (MDA), soluble sugar, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutamine synthetase (GS) activity in leaves at Day 71. B. subtilis and S. cerevisiae combination could promote rice physiological indices, and B. subtilis had a greater effect than S. cerevisiae. There are obvious differences in the physiological performance and soil N between 2018 and 2019 due to the EC of reclaimed water. Redundancy analysis revealed that soil NO3−-N and the mass of B. subtilis applied were major factors influencing leaf physiological indices. Five grams of B. subtilis is recommended to facilitate rice growth after irrigation with reclaimed water. Our research provides a new agronomic measure for the safe utilisation of reclaimed water.

The delimitations of species in Camellia section Camellia have been disputed for many years, resulting from uncertain relationships among species. Leaf morphological and anatomical characters for 54 species and three varieties in this section were investigated to reveal the relationships. Principal component analysis and cluster analysis were conducted using the transformed data for quantitative and qualitative characters from leaf morphology and anatomy. Combining the results of statistical analysis with comparative leaf characters of morphology and anatomy, we discussed the taxonomic treatment of section Camellia by Chang compared with that of Ming and we conclude that section Camellia consists of c. 50 species. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159, 456–476.