Total Number Of Colonies Research Articles

The Dual Inflammasome/Myddosome Inhibitor HT-6184 Restores Erythropoiesis in MDS/AML

Background: The NLRP3 inflammasome is one of the key biological drivers of ineffective hematopoiesis and inflammation in myelodysplastic syndrome (MDS). Inflammasome activation arises from both cell-extrinsic (e.g., Toll-like receptors) and cell-intrinsic signals (e.g., somatic mutations) that direct caspase-1 maturation leading to GATA-1 degradation, myeloid skewing, and pyroptotic cell death. HT-6184 is a potent allosteric inhibitor of the inflammasome scaffold protein NEK7 that blocks inflammasome assembly, promotes ASC speck dissolution, and inhibits myddosome activation of NFκβ. To investigate preclinical activity in MDS, we evaluated HT-6184 in MDS and acute myeloid leukemia (AML) models, including patient-derived sample cultures. Results: Expression of inflammasome pathway components was first assessed by gene expression profiling in a large cohort of MDS bone marrow CD34+-selected cells and healthy age-matched controls. Cellular expression of the inflammasome components, caspase-1, gasdermin D, IL-18 and Pycard was significantly upregulated in MDS specimens compared to healthy controls. Furthermore, cases with the highest expression of inflammasome effectors had significantly inferior overall survival (Log Rank P <0.05). The novel inflammasome inhibitor, HT-6184, was designed to prevent NEK7 from mediating the oligomerization of NLRP3 monomers following an activation signal, ultimately preventing inflammasome assembly. Thus, the structure of HT-6184 was tailored to maximize its interactions with NEK7, rigidifying the protein, and locking it in a conformation that prevents interaction with NLRP3. The allosteric activity of HT-6184 was examined using nano differential scanning fluorimetry and confirmed with limited proteolysis assays, which demonstrated that HT-6184 disrupts NEK7 conformations at single-digit nanomolar concentrations. This was confirmed in cell-based assays showing its ability to inhibit IL-1β release with a 50% inhibitory concentration (IC) of 46 nM in THP-1 cells. These data further correlate with HT-6184 blocking of ASC speck formation with an IC90 of 100 nM in THP-1 cells as well as speck dissolution. HT-6184 also affects the NF-κΒ pathway, by blocking myddosome function and resulting in a decreased expression of an NF-κΒ driven reporter gene, with an IC50 of 10.2 nM in transfected cells. HT-6184 exerts its pharmacological activity by inhibiting the priming and activation steps of the NLRP3 inflammasome. It is pharmacologically active in a human whole blood assay, strongly downregulating the production of pro-inflammatory cytokines. Anti-inflammatory efficacy was also observed in vivo in a murine inflammation model of inflammatory bowel disease. HT-6184 incubation with human monocytes abrogated production of IL-1β and IL-6, reverting human monocytes to a less inflamed state as demonstrated by single cell proteomic studies (isoplexis platform). It similarly decreased IL-1β production from monocytes derived from a TET2 -/+ mouse model that preferentially develops monocytic expansion. Finally, treatment initiation of primary MDS/AML bone marrow specimens (N=10) with HT-6184 in methylcellulose cultures markedly increased erythroid differentiation and reduced myelomonocytic colonies in the majority of samples. This was evidenced by the change in total number of colonies and by fluorescence activated cell sorting (FACS) assessment of differentiation markers (Glycophorin A, CD71, CD11b, CD14) after 14 days of incubation. Inflammasome-directed IL-1β secretion in primary MDS samples was also abrogated by HT-6184 treatment. Conclusions: These findings demonstrate that the novel dual inflammasome/myddosome inhibitor, HT-6184 effectively suppresses myeloid skewing, restores erythroid commitment in MDS/AML specimens, and provides a rationale for clinical development in myeloid malignancies.

The Association of SEPTIN6 Mutations with Pediatric Myelodysplasia

Septin family proteins belong to the RAS-like GTPase superclass and are considered as a structural element of the cytoskeleton. They are evolutionarily conserved and are important in cytokinesis, polarity, cell cycle, vesicle trafficking, and exocytosis. They are implicated in T and B cell lymphomas; and acute myeloid leukemias, where they frequently act as fusion partners with the Mixed-Lineage Leukemia (MLL) gene. Previously, we described two non-syndromic patients with severe neutropenia which progressed to myelodysplastic syndrome (MDS) (Renella et al. AJH, 2022, Mohamad et al. ASH, 2022). Next-generation sequencing revealed both patients (P1 and P2) to have novel X-linked germline mutations in codon 428 of the SEPTIN6 gene (P1: SEPTIN6 c.1282T>C; P2: SEPTIN6 c.1282T>A). One of these patients (P1) had an additional somatic stop-gain mutation (P1: SEPTIN6 c.43C>T) of unclear function. Both patient germline mutations were predicted to add 9 amino acids to the C-terminal end creating a novel mutated SEPTIN6 protein. Since SEPTIN6 is located on the X-chromosome and expression of these mutated proteins occurred in males, no wild-type protein was present in the patient cells. To further explore the biological relevance of these mutations, single base-pair gene editing was used to introduce the (P1: T>C) mutation into normal male donor CD34+ cells. Morphological studies demonstrated that SEPTIN6 edited cells had enlarged, multi-nucleated and dysplastic nuclei; and reduced clonogenic activity. To further assess the effect of the T>C mutation on hematopoietic stem cell (HSC) function, the SEPTIN6 edited cells were transplanted into immunocompromised NSGW mice. Analysis of peripheral blood demonstrated reduced chimerism in edited recipients (4.27% +/-3.4%) compared to controls (20.56% +/-6.2%, mean+/- SD, p= 0.0008) indicating a functional HSC defect upon mutation acquisition. Bulk mRNA sequencing demonstrated changes in ribosome, DNA replication, homologous recombination and mismatch repair pathways which imply DNA damage and cell cycle defects (Figure 1). To examine the potential dominant negative vs haploinsufficiency role of these mutations, we introduced the mutated SEPTIN6 (P1: SEPTIN6 c.1282T>C) cDNA into wild type human male CD34+ cells. Morphological studies demonstrated enlarged cells with multi-nucleated and dysplastic nuclei. Moreover, clonogenic assays demonstrated that cells containing both the mutated and wild type protein had reduced number of colonies (17.7+/- 5.5) compared to controls (127+/- 13.7, mean+/- SD, p <0.0001). This indicates that the mutated SEPTIN6 protein has a dominant negative effect over the wild type protein. We hypothesized that the somatic stop-gain mutation in the patient (P1) genome may mitigate the deleterious effects of the primary germline SEPTIN6 c.1282T>C mutation. To test this hypothesis, and determine the effect of each individual mutation, we created lentivirus vectors which contained a shmiR against the native SEPTIN6 mRNA and also contained (a) the germline P1: SEPTIN6 c.1282T>C mutation (M2 mutation) alone, or (b) the germline M2 mutation and the somatic stop-gain mutation (P1: M1+M2 mutation) in tandem, or (c) germline P2: SEPTIN6 c.1282T>A (M3 mutation). The wild type SEPTIN6 gene was reintroduced as a control. Clonogenic assays demonstrated that SEPTIN6 knockdown in human CD34+ cells caused no significant change in progenitor activity (Table 1). Furthermore, introduction of the M2 or the M3 germline mutants in SEPTIN6 knocked down cells caused a reduction in the total number of colonies, especially the number of GM colonies with no change in the number of BFU-E colonies (Table 1). This data validates our previous experiments performed with single base pair gene editing in human CD34+ cells. Interestingly, introduction of the stop-gain M1 mutation along with the M2 mutation (M1+M2) reversed the reduced clonogenic activity seen with expression of the M2 mutation (Table 1). This indicates that the M1 mutation by introducing an early stop codon creates a SEPTIN6 knockdown effect and rescues hematopoietic function from the deleterious M2 mutation. Overall, our data demonstrates the acquisition of de novo gain of function mutations in the SEPTIN6 gene in myelopoiesis and suggests deleterious effects on engrafting hematopoietic stem cells. These mutations are associated with the development of MDS in two pediatric patients.

Roles of Ribosomal S6 Kinases in Acute Leukemia and Normal Hematopoiesis

Ribosomal S6 kinases (RSKs) are serine-threonine kinases that are activated by the Ras/mitogen activated protein kinase signaling pathways and regulate cell proliferation and survival. There are 4 isoforms of RSK (RSK1, 2, 3, 4), and there is evidence that the isoforms mediate tissue-specific cellular functions. We hypothesized that RSK isoforms have distinct roles in hematopoiesisand evaluated RSK as a target for the treatment of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). To investigate isoform expression in hematopoiesis, we sorted cord blood mononuclear cells into hematopoietic progenitor stages and quantified RSK isoform mRNA by RT-qPCR. RSK1 expression remained consistent throughout hematopoiesis, whereas RSK2 expression decreased in the more differentiated populations. RSK3 was elevated in the lymphoid-primed multipotential progenitor and common myeloid progenitor stages and was greatly reduced in the more mature megakaryocyte-erythroid progenitor population. These results suggest that RSK proteins have isoform-specific roles in hematopoiesis. To analyze the importance of each isoform on hematopoiesis, we transduced cord blood CD34+ cells with lentiviral constructs expressing isoform-specific or control shRNAs. After liquid culture for 5 days, the cells were plated in methylcellulose media containing SCF, IL-3, GM-CSF, and EPO to determine the colony-forming potential. RSK1 and RSK2 knockdown decreased the colony-forming unit - erythroid colonies and increased the granulocyte/macrophage colony numbers. RSK3 knockdown increased the burst-forming unit - erythroid colonies and total colony numbers. After liquid culture days 8, 11, and 14, the erythroid and myeloid populations were analyzed by flow cytometry. RSK1 knockdown increased the CD11b+ and CD14+ myeloid populations and decreased the CD71+ erythroid population. RSK3 knockdown increased the erythroid population and decreased the myeloid populations. These data demonstrate that RSK1 and RSK3 have opposing effects on hematopoietic lineage determination. Overexpression of RSK proteins leads to aberrant cell survival and proliferation in many cancers including leukemia. We have previously reported that RSK and phosphorylated RSK are elevated in pediatric AML and are associated with a worse prognosis. There are only two orally bioavailable RSK inhibitors that have moved to phase I clinical trials: TAS0612 and PMD-026. TAS0612 is a multi-kinase inhibitor of RSK, AKT, and S6K. PMD-026 has high specificity to all four RSK isoforms. We evaluated the effects of both compounds in AML and ALL. To determine the effects of the RSK inhibitors on AML, we treated AML cell lines and patient samples with a range of doses of PMD-026, TAS0612, or 0.1% DMSO. After 3 days, we performed CellTiter Glo assays to determine the relative viable cell number and calculate the concentration of drug that inhibits cell growth by 50% (IC50). TAS0612 had an IC50 of 0.096-0.64 µM in AML cell lines Molm13, U937, AML193, and MV4;11. To test the cytotoxicity of TAS0612 on normal hematopoiesis, we plated healthy bone marrow mononuclear cells with TAS0612 in methylcellulose media. Colony formation was not adversely affected by TAS0612 up to 1 µM. PMD-026 was effective in Molm13, Kasumi-1, and MV4;11 with an IC50 of 0.34-0.55 µM and in AML patient samples 3123 and 4192 with an IC50 of 1.5-2.3 µM. PMD-026 did not affect healthy bone marrow colony formation up to 5 µM for a 2.5- to 10-fold therapeutic window. Furthermore, we tested the effects of RSK inhibitors in ALL. While PMD-026 was not effective, we found that B-ALL cell lines (REH, Nalm-6) and T-ALL cell lines (Loucy, Jurkat) were sensitive to RSK inhibition by TAS0612 with an IC50 of 0.056-0.19 µM. Western blot analysis of RSK protein revealed that RSK1, RSK2, and phospho-RSK proteins are elevated in ALL cell lines compared to healthy peripheral blood mononuclear cells. We are investigating the role of RSK and RSK isoforms in ALL. We found that RSK isoform expression is modified during hematopoiesis. Isoform expression influences early-fate decisions to differentiate into erythroid and myeloid lineages. RSK inhibitors PMD-026 and TAS0612 are effective at targeting AML and ALL cells with limited cytotoxicity to healthy cells, making them promising candidates for translation into clinical trials for AML and ALL.

Septin11 and Septin 8 Play Critical and Overlapping Roles Murine Stem Cell Function

Septins are highly conserved GTP binding proteins which regulate a variety of cellular functions including cytokinesis, polarity, cell cycle, vesicle trafficking, and exocytosis and are now considered the fourth component of the cytoskeleton. Septins are implicated in T and B cell lymphomas; and acute myeloid leukemias, where they frequently act as fusion partners with the Mixed-Lineage Leukemia (MLL) gene. Previous data in our laboratory led to the discovery of a small molecular inhibitor, DW0254, which inhibits RAS function and its downstream target RhoGTPase, Rac, including the hematopoietic-specific Rac2 GTPase, also implicated in MLL leukemias. The inhibitor leads to apoptosis of leukemia cell lines. Using biophysical methods, we discovered that DW0254 binds both the RAS chaperone, PDE6D, and Septin11, which is a member of the Septin6 family (Sara CN, et al., Blood Cancer 2022). Although Septins have been reported to be involved in function of the RhoGTPase Cdc42 and hematopoietic stem progenitor cell (HSPC) polarity, the role of Septin11 in hematopoiesis has not been reported. Septin11 is a member of the Septin6 family of proteins which consists of Septin6, 8, 10, 11 and 14 with significant homology between family members. Previous data in yeast has hypothesized functional overlap within each family of Septin proteins. To better understand the functional role of Septin11, we created lentivirus vectors tagged with a GFP reporter that contained shmiRs against Septin11. Culture of Septin11 knockdown (Septin11 KD) murine HSPC in IMDM (10ng/ml IL-3, 25ng/ml of SCF, TPO, Flt-3 and IL-6) resulted in an average of 13-fold decrease in cell counts compared to controls (p=0.02) and a decrease in total clonogenic activity (Figure 1) with defects seen in both myeloid (GM) and erythroid (BFU-E) colonies. Reduced clonogenic numbers were accompanied by a significant increase in early apoptotic cells suggesting that Septin11 is important in regulating apoptosis in HSPC. To determine the potential role of Septin11 in more primitive hematopoietic cells, we utilized competitive repopulation assays. Transduced BoyJ HSPC (GFP+ Septin11 KD and BFP+ control, mixed 1:1) were injected into lethally irradiated C57Bl/6 mice. We observed a reduction in multilineage chimerism in the peripheral blood, bone marrow, spleen and thymus in primary transplant recipients after knockdown of Septin11 (Table 1). To better define function in specific hematopoietic populations of HSPC, we performed knockdown in FACS-sorted purified cells. Engraftment studies demonstrated a significant reduction in bone marrow chimerism in primary transplant recipients after knockdown of Septin11 most clearly in LT-HSC and ST-HSC (Table 1) with no statistically significant change in MPP. Therefore, to better study the hematopoietic stem cell compartment, we performed secondary transplants utilizing the cells obtained from primary competitive repopulation assays. We observed an unexpected recovery in engraftment in secondary transplant recipients that was accompanied by an increase in the mRNA expression of Septin8. Since Septin8 and Septin11 are closely related we hypothesized that induction of Septin8 was subserving key functions of Septin11. To test this hypothesis, we created a lentivirus vector that expressed both a shmiR against Septin11 and the Septin8 cDNA. Concurrent overexpression of Septin8 with Septin11 knockdown HSPC caused a significant increase in the total number of colonies compared to controls (Figure 1). These data indicate an important role of Septin11 in murine hematopoiesis and a potential redundant role for Septin8.

Распространение, диагностика и профилактика нозематоза пчел

Abstract. Nosema is an infectious disease caused by the microsporidia Nosema cerana and Nosema apis. Adult bees get sick, as a result of which the family weakens and dies. Spores of N. cerana and N. apis, when infecting bees, penetrate into the middle section of the intestine, where the development of vegetative forms of pathogens occurs. The latter predominate in the epithelial cells of the mucous membrane of this part of the intestine and feed on their protoplasm. As a result, epithelial cells die off, as a result of which the intestine loses its functional activity, leading to the weariness of the bees. Families with nosematosis weaken, lose viability, and eventually die. Therefore, the development of measures to combat nosematosis is relevant. The purpose of the study was to study the spread of nosematosis in bees in the conditions of the Northern Trans-Urals and the development of therapeutic and preventive measures. To achieve this goal, the following tasks were set: determine the epizootological state of apiaries located in different natural and climatic zones in the south of the Tyumen region; to establish the effectiveness of therapeutic and preventive measures against nosematosis using herbal remedies. Methods. The work was carried out in the apiaries of the Tyumen region and in the IBiVM laboratory. In order to create an epizootic state of apiaries, bees were sampled in the apiaries of the southern taiga, subtaiga and forest-steppe climatic zones of the Northern Trans-Urals. Adult bees were selected for the study (in the amount of at least 10 % of the total number of bee colonies in each apiary). Experimental work was carried out in accordance with the “Methodological guidelines for setting up experiments in beekeeping” and “Methods for conducting research work in beekeeping”. Results. The data obtained characterize the high degree of infection with nosematosis of bees living in the northern regions. As a result of the research carried out in the laboratory of the State Agrarian University of the Northern Trans-Urals, phytopreparations have been developed, consisting of the flowers of medicinal plants (Achilléa millefólium and Tussilágo) with the juice of Állium satívum. These ingredients help to increase the resistance of families, increasing their viability and resistance to nosematosis. The scientific novelty of the work lies in the fact that in the conditions of the Northern Trans-Urals, an analysis of the epizootic state of apiaries was carried out, depending on their location in natural and climatic zones.

Antifungal Properties of Ozone Treatment against P. citrinum and R. stolonifera in Fresh-Peeled Garlic

Garlic is susceptible to decay and presents a potential vehicle for foodborne disease transmission. Ozone treatment has proven to be an effective and innoxious method to provide bacterial resistance in this globally popular pungent vegetable. This study was conducted to evaluate the effects of different ozone treatments (differing in terms of concentration, treatment time and temperature) against Penicillium citrinum and Rhizopus stolonifer in spoiled fresh-peeled garlic. The results have shown that the most inhibitory conditions for in vitro treatments were achieved with an ozone concentration, treatment time and temperature of 6 ppm, for 20 min at 20 °C, respectively, on the P. citrinum and 8 ppm, for 20 min at 25 °C, respectively, on the R. stolonifer. The optimum in vivo ozone treatment conditions for fresh-peeled garlic inoculated with the same two kinds of spoilage molds remained the same for both, consisting of an ozone concentration of 6 ppm, a time of 15 min and a temperature of 20 °C. Following these ozone treatments, the total number of colonies of yeast and mold, as well as the incidence, lesion diameter and depth of spoilage in the fresh-peeled garlic was significantly reduced during storage, with improved bactericidal inhibition effects. In conclusion, this study showed that ozone treatment effectively inhibits the growth of spoilage molds, destroys cell structures, and affects the metabolic and physiological processes of P. citrinum and R. stolonifer. Thus, it provides a protective shield and extends the shelf life of fresh-peeled garlic.

Bacteria reduction and quality improvement of 3D printed fresh carrots by inner design and moderate microwave treatment

AbstractBacteria reduction and quality change of 3D printed carrots with different infill percentages (%) were studied after being treated with microwave (MW) at three power levels (120, 230, and 390 W). The color, appearance, texture (hardness, chewiness, and gumminess), and total polyphenol contents (TPCs) were comprehensively evaluated. The results showed that infill levels had no effect on bacterial population reduction but significantly affected the appearance of the samples after MW treatment. The total number of colonies (TNCs) were decreased by 0.27–0.68 (120 W, 60 s), 2.24–2.48 (230 W, 60 s), and 4.27–4.54 (390 W, 60 s) log CFU/g under the three MW treatments, respectively. 390 W MW treated achieved a very significant effect on inoculated Escherichia coli, with a death rate of 81.13%. MW treatment enhanced the hardness, chewiness, and TPC of the printed carrots as well as improved sticky mouthfeel without adversely affecting the visual color. The bacterial reduction effect of MW 390 W treatment for 60 s was relatively better. 60% infill sample was the best for the purpose of avoiding surface shrinkage and deformation of low infill samples and surface puffing of high infill samples.Practical applicationsIn this study, fresh vegetables were used for printing and MW sterilization was combined into 3D printing, so as to ensure the microbial safety of 3D printed products and provide technical basis for the sterilization treatment of meat, seafood, and other printed foods susceptible to microbial contamination.

Mildew detection in rice grains based on computer vision and the YOLO convolutional neural network.

At present, detection methods for rice microbial indicators are usually based on microbial culture or sensory detection methods, which are time-consuming or require expertise and thus cannot meet the needs of on-site rice testing when the rice is taken out of storage or traded. In order to develop a fast and non-destructive method for detecting rice mildew, in this paper, micro-computer vision technology is used to collect images of mildewed rice samples from 9 image locations. Then, a YOLO-V5 convolutional neural network model is used to detect moldy areas of rice, and the mold coverage area is estimated. The relationship between the moldy areas and the total number of bacterial colonies in the image is obtained. The results show that the precision and the recall of the established YOLO-v5 model in identifying the mildewed areas of rice in the validation set were 82.1% and 86.5%, respectively. Based on the mean mildewed area identified by the YOLO-v5 model, the precision and recall for light mold detection were 100% and 95.3%, respectively. The proposed method based on micro-computer vision and the YOLO convolutional neural network can be applied to the rapid detection of mildew in rice taken out of storage or traded.

Myelo-Erythroid Lineage Segregation Is Regulated By the GATA-2 Interactome

Hematopoiesis arises from hematopoietic stem cell differentiating into downstream progenitors through a multistep process of sequential lineage potential restriction leading to the final production of >10 hematopoietic cell type.The regulation of hematopoietic lineage development involves synergistic and antagonistic interactions between transcription factors (TF) with lineage-restricted expression patterns, both through protein-protein interaction and direct transcriptional activation.Eosinophils, basophils and mast cells are key myeloid cell types involved in allergic inflammation and have been proposed to arise from a granulocyte-macrophage progenitor (GMP), that also generates neutrophils and macrophages, with GATA-2 up-regulation as a critical determinant. However, recent work identified a distinct basophil/eosinophil/mast cells progenitor (BEMP) that arises from multi-potent erythroid-primed multipotent progenitors (EMPP) where GATA-2 is already expressed ( Drissen et al., 2016). Here, we show that the GATA-2 interactome, rather than GATA-2 expression, controls myeloid lineage choice in EMPPs. To investigate the molecular mechanism instructing lineage decision in EMPP, we performed gene-expression profiling (RNA-seq) comparing its downstream progeny, early restricted erythroid/megakaryocyte progenitor (preMegE) and BEMP. This analysis identified differential expressed genes, including antagonist gene-expression pattern between the LIM-only protein 2 ( Lmo2) and protein 4 ( Lmo4), both previously shown as GATA-2 interactor. While Lmo2 function in hematopoiesis have been exhaustively studied, the role of Lmo4 remains unknown. In colony forming unit (CFU)-assay, overexpression of Lmo4 in EMPP mediated by lentiviral delivery, resulted in an increased number of mast-colonies associated with a decreased of erythroid/megakaryocyte colonies, while the total colony number was unchanged. In addition, transplantation of hematopoietic lineage-negative cells transduced with Lmo4/empty(Ctrl) lentiviral particles, showed an increased frequency of basophils and eosinophils associated with a decrease of erythroid cells in Lmo4 overexpressing cells compared to Ctrl, in both bone marrow and spleen of recipient mice, 8 weeks after transplantation. Analysis of transduced Lineage-negative Kit + (LK) compartment of recipient mice, also revealed an increased frequency of BEMP associated with a decreased frequency of preMegE in Lmo4overexpressing cells compared to Ctrl. Taken together, these data suggested that Lmo4 overexpression instruct lineage decision of EMPP toward basophil/eosinophil/mast lineages.Over-expression followed by co-immunoprecipitation in HEK-293T cell line revealed that LMO4 compete with LMO2 binding to GATA-2, suggesting a mutually exclusive transcriptional complex. More importantly, lack of interaction between LMO4 and GATA-2 mediated by a point mutation in the zinc-finger 1 domain (ZnF1) of GATA-2 (GATA2-G320D), frequently identified in AML/AEL, resulted in an absence of mast lineage potential of EMPP compared to GATA2 +/+. Moreover, over-expression of Lmo4 in EMPP from GATA2 G320D/G320D mice compared to GATA2 +/+, failed to instruct myeloid fate in vitro. Overall, our data identified a specific molecular mechanism of hematopoietic cell fate decision driven by protein-protein interaction with GATA-2. Perturbation of GATA-2 interactome through over-expression of the cofactor Lmo4 or specific point mutation in GATA2 ZnF1 domain results in lineage fate switch of EMPP toward the erythroid/megakaryocyte or basophil/eosinophil/mast lineages.

Effects of chitosan with different molecular weights on storage quality and fungi inhibition of mini-cucumber

The effect of low (LWC, 30 kD), medium (MWC, 150 kD) and high molecular weight chitosan (HWC, 300 kD) coatings on storage quality and fungi inhibition of mini-cucumber was evaluated. Chitosan coatings significantly reduced the weight loss, and delayed the color change and sensory score of mini-cucumber when compared with the control. Chitosan coatings significantly retarded the decrease of DPPH free radical scavenging rate and total phenol content, and inhibited the total number of bacterial colonies and the viable numbers of yeast and molds in mini-cucumber. Chitosan coatings also significantly reduced the disease incidence and disease severity of mini-cucumber artificial inoculated with Botrytis cinerea. LWC coating showed superior preservation effectiveness and antifungal activity to MWC and HWC coating. Compared with the control, LWC coating prolonged the shelf life by 6 days which was evaluated by sensory score, and reduced the total number of bacterial colonies and viable numbers of yeast and molds in mini-cucumber by 4.20 log10 CFU/g and 2.72 log10 CFU/g, respectively. These results suggested that chitosan molecular weights affected preservation effectiveness and antifungal activity against B. cinerea and LWC could be used to prolong the shelf life of mini-cucumber and maintain its quality after harvest.

Back propagation artificial neural network (BP-ANN) for prediction of the quality of gamma-irradiated smoked bacon

This study investigated the effect of gamma irradiation on smoked bacon quality during storage and developed a multi-quality prediction model based on gamma irradiation. Gamma irradiation reduced moisture content and improved the microbial safety of smoked bacon. It also accelerated protein and lipid oxidation and altered free amino acids and fatty acids composition. It was effective in slowing down quality deterioration and sensory quality decline during storage. The backpropagation artificial neural network (BP-ANN) model was constructed by using physical and chemical indicators, irradiation dose, and storage time as input variables, and the total number of colonies and sensory scores as output layers. The transfer functions of the input-hidden layer and hidden-output layer were ReLu and Sigmoid, respectively. There were 13 neurons in the hidden layer. Results showed that BP-ANN based on physical and chemical indicators, irradiation dose, and storage time had great potential in predicting the multiple quality of smoked bacon.

Novel PVA/carboxylated cellulose antimicrobial hydrogel grafted with curcumin and ε-polylysine for chilled chicken preservation.

PVA/CC/CUR/PL composite films containing curcumin (CUR) and ε-polylysine (PL) were prepared by casting and chemical grafting methods to address the threat to food spoilage. Morphological analysis showed that the grafting of CUR and PL resulted in a rough cross-section of the polymer matrix. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the grafting of CUR and PL into the polymer matrix via esterification and amidation reactions, respectively. Thermal weight loss analysis showed that grafting process positively improved the thermal stability. The PVA/CC/CUR/PL films exhibited strong bactericidal activity, reaching 99.0% and 99.8% for Pseudomonas lundensis and Shewanella putrefaciens, respectively. After 8days of storage, the total number of colonies and the TVB-N content in the PVA/CC/CUR/PL group decreased by 1.51 lg CFU/g and 13.77mg/100g, respectively. Therefore, PVA/CC/CUR/PL films are considered as a promising bactericidal material with good mechanical properties, functionality, and other excellent characteristics.

Exploring the potential of ume-derived proanthocyanidins: novel applications for blueberry preservation.

Proanthocyanidins (PCs) extracted from ume have many well-known functional properties. The aim of this study was to explore a novel natural food preservative using ume plum pulp proanthocyanidins (UPPP). The crude product of PCs from ume plum was obtained by using ethanol as extraction solvent and ultrasonic-assisted extraction, and then the pure product of UPPP was obtained by purification with AB-8 resin. The bacteriostatic ability of UPPP and the freshness preservation effect on blueberry were analyzed. The results showed that UPPP had a high inhibitory effect on Staphylococcus aureus (MIC of 1.563 mg/mL) and Escherichia coli (MIC of 3.125 mg/mL). Findings revealed that, in comparison to 0.02% potassium sorbate, blueberries treated with a high concentration of UPPP in a dipping treatment displayed superior quality maintenance after 7 days of storage at 4°C. Importantly, analysis of the various metrics showed that treatment with UPPP was significantly better compared to blueberries treated with 0.02% potassium sorbate. For example, the decay rate, weight loss, and total number of colonies of blueberries treated with 0.02% potassium sorbate were 55.56, 3.48%, and 4.24 ± 0.07 log CFU/mL, whereas the values of the above indexes for blueberries treated with 25 mg/mL of UPPP were 22.22, 3.09%, and 3.10 ± 0.17 log CFU/mL, respectively. Conversely, blueberries that were not dipped in any preservative displayed signs of deterioration as early as the 3rd day of the storage period, highlighting the potential of UPPP as a valuable method for preserving fruits and vegetables. Therefore, UPPP holds great promise as an innovative natural food preservative, effectively enhancing food safety, quality, and extending shelf-life.

High hydrostatic pressure improved properties of peanut sprout juice and its effect on resveratrol

HHP was a nonthermal technology which was widely used in food processing. In this study, HHP was used to process the peanut sprout juice and microbial load, physicochemical properties and antioxidant capacities of peanut sprout juice were found to be improved during 90-day storage. Compared with heat treatment (HT, 95 °C, 10 min), the treatment at 400–600 MPa resulted in greater microbiological stability. No more than 2 lg CFU/g of total plate count (TPC) was observed at 600 MPa for 5 min during a 90-day storage period at 4 °C. The significant negative correlation between the total number of colonies and resveratrol was confirmed, which has bactericidal and bacteriostatic effects. Additionally, resveratrol treated with HHP would degrade and generate new degradation products like p-methylphenol, resorcinol, oxidized resveratrol with higher DPPH scavenging rate, which resulted the higher antioxidation capacity in HHP treated peanut sprout juice. In a word, this study focused on the effect of HHP on peanut sprout juice and the possible degradation behavior of the bioactive resveratrol with HHP treatment, providing a promising processing technology for peanut sprout juice with higher quality.

Analysis of contamination with drug-resistant bacteria among three types of commercially available pork in Beijing and Shanxi,China

The contamination of pork with drug-resistant bacteria seriously affects food safety and human health. This study analyzed the characteristics of contaminating drug-resistant bacteria among three types of commercially available pork (i.e., intensively farmed, organic and free-range). The results revealed that seven antibiotic-resistant strains were present in all three pork samples, and the total number of bacterial colonies of antibiotic-resistant strains in the intensively farmed pork samples was significantly different from those in the organic and free-range pork (P < 0.05), while there was no difference between the organic and free-range pork. The multidrug resistance(MDR) rates were 91.88%, 85.27% and 73.11% for the bacterial isolates from these kinds of pork，which significantly differed between the three types of pork samples (P < 0.05). Nine resistance genes were detected, among which sul1 and aac(6′)-Ib-cr had the highest detection rates of 85.26% and 79.47%, respectively. Class I integron genes were detected in MDR strains from all three types of pork, but only four β-lactam gene cassettes were detected in the intensively farmed strains. In summary, all three types of pork were contaminated with resistant bacteria, but there were differences in the MDR rates and the presence of drug-resistant genes.

Microbial interactions and dynamic changes of volatile flavor compounds during the fermentation of traditional kombucha

This study aims to explore the core microbiota of kombucha and to discover potential correlations between microbiota and volatile flavor compounds. The total acidity and microbial colony numbers changed dramatically in different fermentation periods of kombucha. Microbial analysis based on high throughput sequencing technology showed that the bacteria of Komagataeibacter, Pseudomonas, Burkholderia, Ralstonia, Halomonas, Sphingomonas and fungi of Dekkera, Saccharomyces cerevisiae, Botryotrichum, Monascus, Pichia were the dominant genera. In addition, the correlation coefficients between the bacteria and fungi were different. The volatile flavor compounds of alcohols, acids, esters, aldehydes, ketones, phenolics, and terpenes were identified using headspace solid-phase microextraction combined with gas chromatography coupled with mass spectrometry. Typically, the concentrations of ethanol, acetic acid, and ethyl acetate was 71.59–248.23 μg/L, 97.73–849.00 μg/L, and 44.52–181.59 μg/L, respectively, during fermentation. This study is helpful to understand the dynamic changes of microbial communities and volatile flavor compounds during the fermentation of kombucha.

Occurrence of metals, phthalate esters, and perfluoroalkyl substances in cellar water and their relationship with bacterial community in rural areas of China

Water cellars are traditional rainwater harvesting facilities that have been widely used in rural areas of northwest China. However, there are few reports about the water quality and health risk caused by the cellar water, especially phthalate esters (PAEs) and perfluoroalkyl substances (PFASs). This study investigated and assessed the health risks caused by the metals, PAEs, PFASs and bacterial communities in cellar water. The results showed that the turbidity and total number of bacterial colonies ranged from 4.7 to 58.5 NTU and 5–557 CFU/mL, respectively. The turbidity and total number of bacterial colonies were the main water quality problems. Due to high concentration of Tl (0.005–0.171 μg/L), the samples reached a high level of metal pollution. PAEs showed no non-carcinogenic and carcinogenic risk. The perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonate (PFOS) were the main components of PFASs. PFOA and PFOS reached a moderate risk level in many cellar water samples. Moreover, Tl, Pb, As, PFBA and PFBS could change the bacterial community composition and induce the enrichment of bacterial functions related to human diseases. Besides these parameters, dissolved oxygen (DO) also affected the bacterial functions related to human diseases. Therefore, more attention should be paid to turbidity, DO, Tl, Pb, As, PFOA, PFOS, PFBA and PFBS in the cellar water. These results are meaningful for the water quality guarantee and health protection in rural areas of China.

Improving the technique of protecting concrete floors in poultry houses

The object of the study was concrete floors in a poultry house with different types of litter. The paper addressed the problem of reducing microorganism contamination of concrete floors in poultry houses to prevent biological corrosion. Corrosion of the surface of the concrete floor in the form of the formation of calcium oxalate monohydrate crystals was established by scanning electron microscopy; microscopic fungi: A. pullulans, F. sporotrichioides, and A. niger were detected. The TPD MS method established that concrete samples obtained in a room with straw lose moisture by 51.52 % more, with granules – by 342.42 % (р≤0.05), with shavings by 6.06 %, compared to control. CO from concrete samples is released less with sawdust litter by 86.40 %, with straw – by 83.49 %, with shavings – by 76.69 %, with granules – by 69.90 % (р≤0.05). The CO2 content in concrete samples from the room with sawdust was lower by 86.88 % (р≤0.05), with straw – by 55.73 %, with shavings – by 38.52 %, with granules – by 23.77 %, compared to control without litter. Microbiological studies have established that 48 hours after disinfection, the total number of colonies of microorganisms on a concrete floor with a sawdust litter likely decreased by an average of 90.19 %, straw – by 91.62 %, shavings – by 79.76 %, granules – by 82.88 % (р≤0.05), in the control – by 83.73 %. It can be argued that the disinfectant destroys microorganisms on the concrete surface regardless of the type of substrate. The peculiarity of the experiment was the use of scanning electron microscopy and TPD MS methods to study structural changes in concrete. The research is distinguished by the use of a powdered disinfectant to reduce microbial damage to a concrete floor with different types of litter. The results of the experiment could be used in the aggressive environment of poultry houses to reduce the impact on concrete structures

Influence of dry season on social wasp communities (Hymenoptera: Polistinae) in Deciduous Forest

The seasonal deciduous forest, also known as dry forest, is characterized by the deciduity of tree species and two well-defined seasons which cause drastic changes in its physiognomy, and the seasonality of rainy periods directly impacts the forest’s biological communities. Social wasps (Vespidae: Polistinae) are well documented. However, some ecosystems in which they occur, such as the deciduous forest, are still subsampled. This study aimed to assess the response of social wasp communities to the dry season in a deciduous forest in the Mata Seca State Park, in the North of the state of Minas Gerais, Brazil. Insects were collected over 24 days divided into four field campaigns, each with six continuous days of collection (February, May, July, and November 2021), encompassing one campaign per season. All specimens were sacrificed and stored in 70% alcohol and later dry mounted for identification. The Kruskal-Wallis (KW) H test was performed to verify the difference between species richness, number of total colonies, and number of colonies of each tribe in relation to the collection station. In total, 131 colonies of eight species were located, particularly Polybia occidentalis (Olivier, 179), with 39 colonies, Polistes versicolor (Olivier, 1791), with 33, Mischocyttarus cassununga, with 21, and Protonectarina sylveirae (Saussure, 1854), with 13. Six species, five of which were from the Epiponini tribe, were collected in the four seasons. The responses of social wasps to the periods of drought in the deciduous forest vary with tribe. While Epiponini populations can keep colonies active in the dry season, Polistini cannot. Meanwhile, P. versicolor responds positively to the onset of the rainy season, increasing its population.

Effects of Rhizophagus intraradices and Acinetobacter calcoaceticus on Soybean Growth and Carbendazim Residue

In agricultural production, carbendazim and other pesticides are used to prevent soybean root rot. However, carbendazim degrades slowly and affects a series of biochemical processes such as soil biological nitrogen fixation and soil nutrient activation in the natural environment. This study mainly investigated the effects of Rhizophagus intraradices, Acinetobacter calcoaceticus, and carbendazim on soybean biomass, the incidence of root rot, the total number of bacterial colonies and phosphorus-solubilizing bacteria in rhizosphere soil, and carbendazim residue in soybean grains and rhizosphere soil. The results showed that the arbuscular mycorrhizal fungi (AMF) spore density, AMF infection rate, soybean biomass, nodule number, total bacterial colonies, and phosphorus-solubilizing bacteria colonies in the soybean rhizosphere soil were the highest in the R. intraradices and A. calcoaceticus treatment groups under natural soil conditions. Moreover, the incidence of root rot and carbendazim residue in soybean grains and rhizosphere soil were the lowest in the R. intraradices and A. calcoaceticus treatment group under natural soil conditions. This result indicated that R. intraradices and A. calcoaceticus can effectively reduce carbendazim residue in soybean grains and rhizosphere soil. This study provided theoretical support for the development of microbial fertilizer and microbial degradation of pesticide residues and improved the practical basis for ensuring food safety.