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Candida auris emerged as a pathogenic species of fungus that causes severe and invasive outbreaks worldwide. The fungus exhibits high intrinsic resistance rates to various first-line antifungals, and the underlying molecular mechanism responsible for its multidrug resistance is still unclear. In this study, a transcriptomic analysis was performed between two C. auris isolates that exhibited different anti-drug patterns by RNA-sequencing, namely, CX1 (anti-drug sensitive) and CX2 (resistant). Transcriptomic analysis results revealed 541 upregulated and 453 downregulated genes in the resistant C. auris strain compared with the susceptible strain. In addition, our findings highlight the presence of potential differentially expressed genes (DEGs), which may play a role in drug resistance, including genes involved in ergosterol and efflux pump biosynthesis such as SNQ2 , CDR4 , ARB1 , MDR1 , MRR1 , and ERG genes. We also found that Hsp related genes were upregulated for expression in the anti-drug-resistant strain. Biofilm formation and growth conditions were also compared between the two isolates. Our study provides novel clues for future studies in terms of understanding multidrug resistance mechanisms of C. auris strains. [ABSTRACT FROM AUTHOR]

Highlights • Responses of soil respiration to rainfall pulse were analyzed in an oak forest. • Drought affects the response of soil respiration to rainfall event. • Larger soil respiration response to rainfall is found under severe drought. • Drought rather than precipitation size affects rainfall induced total C loss. Abstract As a consequence of climate change, a higher frequency of spring drought periods followed by episodic precipitation events is predicted for Central China. Little is known about the effect of drought intensity on the response of soil CO 2 efflux to discrete precipitation events in forest ecosystems. A field experiment was conducted to assess the responses of soil CO 2 efflux to spring drought and precipitation pulse in an oak forest located at climatic transitional zone in Central China. Soil respiration (SR) and heterotrophic respiration (HR) under 30-day drought showed higher responses to precipitation pulse than those under control and 20- day drought treatments. Regardless of drought intensity, precipitation events of 5, 10, and 20 mm levels significantly increased SR by 86.0, 103.4, and 175.2%, and HR by 108.4, 129.5, and 161.5% when compared with non-water addition plots, respectively. Severe drought treatment (30-day drought) amplified the contribution of HR to SR in response to precipitation pulse (84.5% vs 78.3% for the control). Drought intensity rather than precipitation amount showed substantial influence on total carbon loss through SR and HR. These findings highlight the importance of incorporating both drought intensity and precipitation events and their impacts on soil carbon cycling into future predictions of forest ecosystems under climate change. [ABSTRACT FROM AUTHOR]

Lakes are an important natural source of CH4 to the atmosphere. However, the multi-seasonal CH4 efflux from lakes has been rarely studied. In this study, the CH4 efflux from Poyang Hu, the largest freshwater lake in China, was measured monthly over a 4-year period by using the floating-chamber technique. The mean annual CH4 efflux throughout the 4 years was 0.54 mmol m-2 day-1, ranging from 0.47 to 0.60 mmol m-2 day-1. The CH4 efflux had a high seasonal variation with an average summer (June to August) efflux of 1.34 mmol m-2 day-1 and winter (December to February) efflux of merely 0.18 mmol m-2 day-1. The efflux showed no apparent diel pattern, although most of the peak effluxes appeared in the late morning, from 10:00 to 12:00 CST (GMTC8). Multivariate stepwise regression on a seasonal scale showed that environmental factors, such as sediment temperature, sediment total nitrogen content, dissolved oxygen, and total phosphorus content in the water, mainly regulated the CH4 efflux. However, the CH4 efflux only showed a strong positive linear correlation with wind speed within 1 day on a bihourly scale in the multivariate regression analyses but almost no correlation with wind speed on diurnal and seasonal scales. [ABSTRACT FROM AUTHOR]

Heavy grazing and unsuitable farming practices have led to grassland degradation in northern China. This study examined soil CO 2 efflux (Fc) from five land-use types during the non-growing season on the southeastern edge of the Mongolian Plateau in China. The land-use types included three native vegetation steppes subjected to differing stocking rates [ungrazed (UG), moderately grazed (MG) and heavily grazed (HG)], a fertilized annual cropland (CL) and a perennial pasture (PP) used for haying and winter grazing. Values of Fc were measured at 3-day to 2-week intervals during the non-growing season in two contrasting hydrological years (2012-13 and 2013-14) using closed chambers. The Fc during 1 Oct. 2013 to 30 April 2014 averaged 475 mg C m −2 for all sites compared to a significantly (P < 0.05) lower Fc (102 mg C m −2 ) during 1 Oct. 2012 to 30 April 2013. The seasonal Fc patterns followed the same trend during the two non-growing seasons with greater Fc observed in the autumn and spring freeze-thaw periods compared to the winter permanently frozen period, which accounted for 4.8% of accumulated total non-growing season Fc. The heavily grazed site showed less soil CO 2 efflux compared to UG, MG, PP and CL land-use types due to a larger reduction in gross primary productivity (GPP) compared to ecosystem respiration. Grazing reduced Fc by 23% for MG and 32% for HG compared to UG. Soil CO 2 efflux from the PP land-use type, which was grazed during the non-growing season, was 23% greater than that from the UG and CL land-use types. Air temperature during the non-growing season was the main factor controlling soil CO 2 efflux (R 2 = 0.40, P < 0.001), although soil water content also played a role. Precipitation received during the growing season had a large legacy effect on Fc. Annual weather variation overshadowed the influence of land-use types on Fc. [ABSTRACT FROM AUTHOR]

In order to study the diurnal variation of soil CO efflux from temperate meadow steppes in Northeast China, and determine the best time for observation, a field experiment was conducted with a LI-6400 soil CO flux system under five typical plant communities ( Suaeda glauca (Sg), Chloris virgata (Cv), Puccinellia distans (Pd), Leymus chinensis (Lc) and Phragmites australis (Pa)) and an alkali-spot land (As) at the meadow steppe of western Songnen Plain. The results showed that the diurnal variation of soil CO efflux exhibited a single peak curve in the growing season. Diurnal maximum soil respiration (Rs) often appeared between 11:00 and 13:00, while the minimum occurred at 21:00-23:00 or before dawn. Air temperature near the soil surface (Ta) and soil temperature at 10 cm depth (T) exerted dominant control on the diurnal variations of soil respiration. The time-windows 7:00-9:00 could be used as the optimal measuring time to represent the daily mean soil CO efflux at the Cv, Pd, Lc and Pa sites. The daily mean soil CO efflux was close to the soil CO efflux from 15:00 to 17:00 and the mean of 2 individual soil CO efflux from 15:00 to 19:00 at the As and Sg sites, respectively. During nocturnal hours, negative soil CO fluxes (CO downwards into the soil) were frequently observed at the As and Sg sites, the magnitude of the negative CO fluxes were 0.10-1.55 μmol/(m·s) and 0.10-0.69 μmol/(m·s) at the two sites. The results implied that alkaline soils could absorb CO under natural condition, which might have significant implications to the global carbon budget accounting. [ABSTRACT FROM AUTHOR]

Antibiotic resistance in bacteria has become a major global health problem. One of the main reservoirs of antibiotic resistance genes is the human gut microbiota. To characterise these genes, a metagenomic approach was used. In this study, a comprehensive antibiotic resistome catalog was established using fecal samples from 246 healthy individuals from world's longevity township in Jiaoling, China. In total, 606 antibiotic resistance genes were detected. Our results indicated that antibiotic resistance genes in the human gut microbiota accumulate and become more complex with age as older groups harbour the highest abundance of these genes. Tetracycline resistance gene type tetQ was the most abundant group of antibiotic resistance genes in gut microbiota, and the main carrier of antibiotic resistance genes was Bacteroides. Antibiotic efflux, inactivation, and target alteration were found to be the dominant antimicrobial resistance mechanisms. This research may help to establish a comprehensive antibiotic resistance catalog that includes extremely long-lived healthy people such as centenarians, and may provide potential recommendations for controlling the use of antibiotics. [ABSTRACT FROM AUTHOR]

The aims of this study were to compare the antimicrobial efficacy of Eravacycline (Erava) versus tigecycline (Tig) in vitro against clinical isolates of S. agalactiae from China and further to evaluate the heteroresistance risk and resistance mechanisms of Erava. 162 clinical isolates of S. agalactiae were collected retrospectively and the minimal inhibitory concentrations (MICs) of Erava and Tig were determined by agar dilution. Moreover, Tetracycline (Tet) specific resistance genes, genetic mutations in Tet target sites, and sequence types (ST) profiles of clinical isolates of S. agalactiae were investigated with polymerase chain reaction (PCR) experiments. The heteroresistance frequency of Erava and Tig in S. agalactiae was analyzed by population analysis profiling. Furthermore, the resistance mechanisms of both Erava and Tig were investigated in antibiotic-induced resistant S. agalactiae isolates in vitro. The MIC values of Erava and Tig were shown with ≤0.25 mg/L and ≤0.5 mg/L, respectively, against clinical S. agalactiae isolates, including that harboring the Tet-specific resistance genes tet (K), tet (M), or tet (O). The heteroresistance frequency of Tig among the clinical isolates of S. agalactiae was 1.84% (3/162), whereas no positive Erava heteroresistance was found. The enhanced MIC values of both Erava and Tig in the heteroresistance-derivative S. agalactiae clones could be reversed by the efflux pump inhibition experiments. Genetic mutations affecting 30S ribosome units (16SrRNA copies or 30S ribosome protein S10) could result in the cross resistance toward Erava and Tig in the antibiotic-induced resistant S. agalactiae isolates in vitro. Erava MIC values were nearly half of that of Tig against the clinical isolates of S. agalactiae from China and genetic mutations in the 30S ribosome units of Tet target sites (16SrRNA copies or 30S ribosome protein S10) participated in the resistance evolution of both Erava and Tig under the antibiotic pressure. • Erava exhibited robust in vitro antibacterial activity with MIC value ≤ 0.25mg/L against clinical isolates of S. agalactiae. • The heteroresistance frequency of tigecycline was 1.84% (3/162), whereas no Erava heteroresistance was found. • The MICs of Erava and Tig in the heteroresistance-derivative S. agalactiae clones were reversed by efflux pump inhibition. • The Lys57Arg mutation in the 30S ribosomal protein S10 was commonly found in the antibiotic-induced resistant S. agalactiae. [ABSTRACT FROM AUTHOR]

• In the interaction system, the DEGs of C. gloeosporioides s.s. were analyzed. • The response model of C. gloeosporioides s.s. to B. amyloliquefaciens was discussed. • The hypothetical response strategies of C. gloeosporioides s.s. was validated. Walnut is cultivated all over the world for its precious woody nut and edible oil. Walnut anthracnose caused by Colletotrichum spp. is a disastrous disease in the walnut plantation. In China, this disease is difficult to control. The efficacies of the traditional preventing and controlling measures are inadequate. It causes serious losses every year. In the interaction systems of 'antagonistic organism-pathogen', the response mechanisms of the pathogen to the stress of antagonistic organisms were largely unknown. To understand the response mechanisms of walnut anthracnose pathogen, Colletotrichum gloeosporioides sensu stricto (s.s.) TS-09R was treated with Bacillus amyloliquefaciens , and RNAseq gene expression analyses were performed. A total of 610 genes expressed differentially (DEGs). Among these genes, 387 genes were up-regulated and 223 genes were down-regulated. Gene ontology (GO) analysis showed that 409 DEGs involved in the categories of biological process, and cellular component. The KEGG pathway enrichment analysis showed that all up-regulated DEGs were enriched in amino acid metabolism, biosynthesis of other secondary metabolites, and xenobiotics biodegradation and metabolism. Further analyses indicated that C. gloeosporioides s.s. TS-09R up-expressed significantly some DEGs associated with cell membrane synthesis and, or maintaining stabilization, antioxidant and anti-stress to build the cell membrane, maintain the normal physiological function of cells. At the same time, it improved detoxification efficiency and reduced its sensitivity to the exogenous antimicrobial substance (EAS). It also improved the activity of the efflux pump translocating EAS out of the cells, reduced accumulation, and minimized injuries to cells. C. gloeosporioides s.s. TS-09R also up-expressed significantly genes associated with sporulation to promote spore production for survival in adversity. C. gloeosporioides s.s. TS-09R recruited numerous genes to respond to or resist the biocontrol of B. amyloliquefaciens. The response model was a holistic and complex network involving multiple genes and multiple signaling pathways. Additionally, the glutathione-S-transferases (GST) activities of C. gloeosporioides s.s. TS-09R, TS-09 cultured for 5 days and 9 days were calculated, and the GST activity had a similar change trend to the GST-related gene expression. The result indicated that the hypothetical response strategies were reliable. In this paper, we provided new insights into the onset of the interaction system of ' C. gloeosporioides s.s. – B. amyloliquefaciens '. The results will contribute to exploring comprehensively the mechanism of B. amyloliquefaciens according to the response mechanisms of C. gloeosporioides s.s. [ABSTRACT FROM AUTHOR]