A new screening method for discovering antibacterial agents from filamentous fungi

Rapid development of resistance among major bacterial pathogens renders antibiotics more and more ineffective and it is crucial to find novel antibiotics for controlling these pathogens. Since high-throughput screening (HTS) that selects antibacterial agents according to targets in vitro rather than whole-cell have not proven effective in the discovery of new antibiotics; new approaches for discovering the next generation of antibiotics are urgently needed. Filamentous fungi are an important source for many of the antibiotics currently used, but screening them for novel antibiotics is difficult primarily due to the lack of efficient screening methods capable of maintaining whole bacterial cell metabolism. In this study, mixed agar plate culture (MAPC) screening method is described. The method maintains the advantages of traditional whole-cell screening but offers increased screening efficiency. Furthermore, its simplicity and convenience makes it suitable for many laboratories. MAPC screening increases the probability of discovering novel antibacterial agents from filamentous fungi under laboratory conditions.Keywords: Drug-resistant bacterial pathogens, novel antibiotics; screening method, filamentous fungi product

Allogeneic haematopoietic stem cell transplantation with decitabine-containing preconditioning regimen in TP53-mutant myelodysplastic syndromes: A case study

Myelodysplastic syndrome (MDS) with TP53 mutations has a poor prognosis after transplantation, and novel therapeutic means are urgently needed. Decitabine (Dec) monotherapy has demonstrated improved overall response rates in MDS and acute myeloid leukaemia, although these responses were not durable. This study aimed to preliminary evaluate the efficacy of a Dec-containing allogeneic haematopoietic stem cell transplantation (allo-HSCT) preconditioning regimen in TP53-mutant MDS. Nine patients with TP53-mutant myelodysplastic syndromes received the decitabine-containing preconditioning regimen and subsequent myeloablative allo-HCT between April 2013 and September 2021 in different centres. At a median follow-up of 42 months (range, 5 to 61 months), the overall survival (OS) was 89% (8/9), progression-free survival (PFS) was 89% (8/9), and relapse incidence was 11.1%. The incidence of severe acute (grade III-IV) graft-versus-host disease (GVHD) was 22.2% (2/9) and that of chronic moderate-to-severe GVHD was 11.1% (1/9). The 1-year GVHD-free/relapse-free survival (GRFS) was 56% (5/9). In conclusion, we found real-world clinical data that supports the use of a Dec-containing preconditioning regimen before allo-HSCT for possible improved outcomes in TP53-mutant MDS patients; there is therefore an urgent call for an in-depth exploration of the involved mechanism to confirm these preliminary findings

Short-term variation in zooplankton community from Daya Bay with outbreaks of <I>Penilia avirost</I>ris

The zooplankton community structure in bays fluctuates as a result of anthropogenic activities in such waters. We focused on the short-term variability of a zooplankton community and compared its differences at the outflow of a nuclear power plant (ONPP), in a marine cage-culture area (MCCA) and in unpolluted waters (UW) in the south-west part of Daya Bay from 28 April to 1 June 2001. Environmental factors and zooplankton abundance differed significantly among stations at ONPP, MCCA and UW: high temperatures and a high zooplankton abundance occurred at ONPP, while a high chlorophyll a concentration and a low zooplankton abundance prevailed in MCCA. Statistical analysis revealed that the zooplankton diversity and abundance could be reduced by the activity of the marine cage-culture in a short time. Penilia avirostris made up an important component of the zooplankton in the study area, its abundance ranging widely from 16 to 7267 indiv. m-3 from April to June and peaking at the ONPP outflow. The outbreak of P. avirostris probably resulted from the combined effects of favourable water temperature, food concentration and its parthenogenetic behaviour

Differential Physiological Responses of Small Thalassiosira pseudonana and Large Thalassiosira punctigera to the Shifted-High Light and Nitrogen

With global warming, the intensity and frequency of extreme episodic weather events such as typhoons are rising in tropical and subtropical regions, disturbing the water column and shifting phytoplankton therein from deep to surface layers, and exposing them to high light as well as nutrients. To explore how phytoplankton respond to such environmental changes, we tracked the growth, cell compositions and physiology of small Thalassiosira pseudonana and large Thalassiosira punctigera from simulated ambient to upward-shifted light and nitrogen (N) conditions. Shifting to high levels of light caused a limited effect on the growth of small T. pseudonana, but reduced that of large T. punctigera by 36%, with supplemental N alleviating the light-caused growth reduction. The upward-shifted light reduced the cellular pigments contents in small T. pseudonana, but not in large T. punctigera. The upward-shifted light reduced the photosynthetic capability (FV/FM) of both species, as well as the light utilization efficiency (α) and maximal relative electron transport rate (rETRmax), but it enhanced their dark reparations. Moreover, the upward-shifted light did not affect the superoxide dismutase (SOD) activity of small T. pseudonana, but it did enhance that of large T. punctigera. In addition, the supplemental N showed a limited effect on cellular pigments and the dark respiration of T. pseudonana, but it reduced that of T. punctigera. Our results showed that the growth responses of Thalassiosira to upward-shifted light and nitrogen vary with species and possibly with cell size, indicating that the field species composition might change after the occurrence of extreme weather events

Unraveling Heterogeneity of Coral Microbiome Assemblages in Tropical and Subtropical Corals in the South China Sea

Understanding the coral microbiome is critical for predicting the fidelity of coral symbiosis with growing surface seawater temperature (SST). However, how the coral microbiome will respond to increasing SST is still understudied. Here, we compared the coral microbiome assemblages among 73 samples across six typical South China Sea coral species in two thermal regimes. The results revealed that the composition of microbiome varied across both coral species and thermal regimes, except for Porites lutea. The tropical coral microbiome displayed stronger heterogeneity and had a more un-compacted ecological network than subtropical coral microbiome. The coral microbiome was more strongly determined by environmental factors than host specificity. gamma- (32%) and alpha-proteobacteria (19%), Bacteroidetes (14%), Firmicutes (14%), Actinobacteria (6%) and Cyanobacteria (2%) dominated the coral microbiome. Additionally, bacteria inferred to play potential roles in host nutrients metabolism, several keystone bacteria detected in human and plant rhizospheric microbiome were retrieved in explored corals. This study not only disentangles how different host taxa and microbiome interact and how such an interaction is affected by thermal regimes, but also identifies previously unrecognized keystone bacteria in corals, and also infers the community structure of coral microbiome will be changed from a compacted to an un-compacted network under elevated SST

Diversity and abundance of epipelagic larvaceans and calanoid copepods in the eastern equatorial Indian Ocean during the spring inter-monsoon

1371-1380This study investigated the species composition, distribution and abundance of larvaceans and calanoid copepods in the eastern equatorial Indian Ocean. In total, 25 species of larvaceans and 69 species of calanoid copepods were identified in the study area. Although the average diversity and evenness indexes of larvaceans were lower than those of calanoid copepods, the abundance of larvaceans was higher than that of calanoids with means of 40.1±14.9 ind m-3 and 28.4±9.1 ind m-3, respectively. Larvacean community was numerically dominated by Oikopleura fusiformis, Oikopleura longicauda, Oikopleura cophocerca, Fritillaria formica and Fritillaria pellucida, accounting for 83% of total larvacean abundance. The calanoid community was dominated by the following five species, represented 61% of calanoid copepods: Clausocalanus furcatus, Clausocalanus farrani, Acartia negligens, Acrocalanus longicornis as well as the copepodite stage of Euchaeta spp. This study highlights that the importance of larvaceans in the eastern equatorial Indian Ocean

Phytoplankton responses to aluminum enrichment in the South China Sea

Compared to extensive studies reporting the aluminum (Al) toxicity to terrestrial plants and freshwater organisms, very little is known about how marine phytoplankton responds to Al in the field. Here we report the marine phytoplankton responses to Al enrichment in the South China Sea (SCS) using on-deck bottle incubation experiments during eight cruises from May 2010 to November 2013. Generally, Al addition alone enhanced the growth of diatom and Trichodesmium, and nitrogen fixation, but it inhibited the growth of dinoflagellates and Synechococcus. Nevertheless, Al addition alone did not influence the chlorophyll a concentration of the entire phytoplankton assemblages. By adding nitrate and phosphate simultaneously, Al enrichment led to substantial increases in chlorophyll a concentration (especially that of the picophytoplankton &lt; 3 mu m), and cell abundances of diatom and photosynthetic picoeukaryotes. These results indicate varied responses of phytoplankton in different size fractions and taxonomic groups to Al enrichment. Further, by simultaneously adding different macronutrients and/or sufficient trace metals including iron, we found that the phytoplankton responses to Al enrichment were relevant to nutrients coexisting in the environment. Al enrichment may give some phytoplankton a competitive edge over using nutrients, especially the limited ones. The possible influences of Al on the competitors and grazers (predators) of some phytoplankton might indirectly contribute to the positive responses of the phytoplankton to Al enrichment. Our results indicate that Al may influence marine carbon cycle by impacting phytoplankton growth and structure in natural seawater

π-section tunable matching network with patterned ferroelectric thin film

10.1002/mop.23942Microwave and Optical Technology Letters50123251-3254MOTL