Inoculation Dose Research Articles

Effect of 13-valent pneumococcal conjugate vaccine on experimental carriage of Streptococcus pneumoniae serotype 6B in Blantyre, Malawi: a randomised controlled trial and controlled human infection study

The effect of childhood pneumococcal conjugate vaccine implementation in Malawi is threatened by absence of herd effect. There is persistent vaccine-type pneumococcal carriage in both vaccinated children and the wider community. We aimed to use a human infection study to measure 13-valent pneumococcal conjugate vaccine (PCV13) efficacy against pneumococcal carriage. We did a double-blind, parallel-arm, randomised controlled trial investigating the efficacy of PCV13 or placebo against experimental pneumococcal carriage of Streptococcus pneumoniae serotype 6B (strain BHN418) among healthy adults (aged 18-40 years) from Blantyre, Malawi. We randomly assigned participants (1:1) to receive PCV13 or placebo. PCV13 and placebo doses were prepared by an unmasked pharmacist to maintain research team and participant masking with identification only by a randomisation identification number and barcode. 4 weeks after receiving either PCV13 or placebo, participants were challenged with 20 000 colony forming units (CFUs) per naris, 80 000 CFUs per naris, or 160 000 CFUs per naris by intranasal inoculation. The primary endpoint was experimental pneumococcal carriage, established by culture of nasal wash at 2, 7, and 14 days. Vaccine efficacy was estimated per protocol by means of a log-binomial model adjusting for inoculation dose. The trial is registered with the Pan African Clinical Trials Registry, PACTR202008503507113, and is now closed. Recruitment commenced on April 27, 2021 and the final visit was completed on Sept 12, 2022. 204 participants completed the study protocol (98 PCV13, 106 placebo). There were lower carriage rates in the vaccine group at all three inoculation doses (0 of 21 vs two [11%] of 19 at 20 000 CFUs per naris; six [18%] of 33 vs 12 [29%] of 41 at 80 000 CFUs per naris, and four [9%] of 44 vs 16 [35%] of 46 at 160 000 CFUs per naris). The overall carriage rate was lower in the vaccine group compared with the placebo group (ten [10%] of 98 vs 30 [28%] of 106; Fisher's p value=0·0013) and the vaccine efficacy against carriage was estimated at 62·4% (95% CI 27·7-80·4). There were no severe adverse events related to vaccination or inoculation of pneumococci. This is, to our knowledge, the first human challenge study to test the efficacy of a pneumococcal vaccine against pneumococcal carriage in Africa, which can now be used to establish vaccine-induced correlates of protection and compare alternative strategies to prevent pneumococcal carriage. This powerful tool could lead to new means to enhance reduction in pneumococcal carriage after vaccination. Wellcome Trust.

Inoculation with Azospirillum brasilense Strains AbV5 and AbV6 Increases Nutrition, Chlorophyll, and Leaf Yield of Hydroponic Lettuce.

Inoculation with Azospirillum brasilense has promisingly increased plant yield and nutrient acquisition. The study aimed to estimate the dose of A. brasilense that increases yield, gas exchange, nutrition, and foliar nitrate reduction. The research was carried out in a greenhouse at Ilha Solteira, in a hydroponic system in randomized blocks with four replicates. The treatments consisted of doses of inoculation with A. brasilense strains AbV5 and AbV6 via nutrient solution (0, 8, 16, 32, and 64 mL 100 L-1). Inoculation with A. brasilense at calculated doses between 20 and 44 mL provided the highest fresh and dry mass of shoots and roots, number of leaves, and leaf yield. In addition, the calculated doses of inoculation with A. brasilense increased the accumulation of N, P, K, Ca, Mg, S, B, Fe, Mn, and Zn in shoots and roots, except the accumulation of Ca in roots. It also increased cell membrane integrity index (15%), relative water content (13%), net photosynthesis rate (85%), intracellular CO2 concentration (15%), total chlorophyll (46%), stomatal conductance (56%), transpiration (15%), and water use efficiency (59%). Hence, inoculation with A. brasilense at doses between 20 and 44 mL 100 L-1 is considered the best approach for increasing the growth, yield, accumulation of nutrients, and gas exchange of hydroponically grown iceberg lettuce.

Isolation and Optimization of Aflatoxin B1 Degradation by Uniform Design and Complete Genome Sequencing of Novel Deep-Sea Kocuria rosea Strain 13.

Aflatoxin B1 is a natural carcinogenic mycotoxin. The biological detoxification of aflatoxin could result in less environmental pollution, more moderate conditions, and less impact on food and feed, and be more convenient than physical and chemical methods. In this study, strain 13 with aflatoxin B1 degradation activity (67.47 ± 1.44%) was isolated and identified as Kocuria rosea. A uniform design was applied to optimize the degradation activity using a software Data Processing System, and a quadratic polynomial stepwise regression model was selected to investigate the relationships between the degradation rate and five independent variables. Furthermore, the optimal degradation conditions (culture temperature of 30 °C, culture time of 4.2 days, seawater ratio of 100%, pH of 7.11, and inoculation dosage of 0.09%) were verified with a degradation rate of 88 ± 0.03%, which was well matched with the predicted value (92.97%) of the model. Complete genome sequencing of Kocuria rosea, conducted with a combination of Illumina and single-molecule real-time sequencing, was used to analyze the genomic features and functions of the strain, which were predicted by the annotation based on seven databases, and may provide insights into the potential of Kocuria rosea, as well as providing a reference for degradation gene and protein mining. These results indicate that Kocuria rosea strain 13 has the ability to degrade aflatoxin B1 efficiently, and it also has the potential to provide aflatoxin-degrading enzymes.

Nutrients Content of Polianthes tuberosa Plant Waste Fermentation with Aspergillus niger as Alternative Feed Ingredients for Ruminant

The purpose of this study was to analyze the nutritional content such as organic matter, crude protein, crude fat, crude fiber, and non-nitrogen extract materials from the waste of the tuberose flower (Polianthes tuberosa) that was fermented by Aspergillus niger as ruminant feed. The materials used were Aspergillus niger with the availability of inoculant 2.46 x 108 CFU/g, tuberose flower waste, water and molasses. The research method uses the experimental method consisting of 5 treatments and 4 replications. Each treatment used a different dose of Aspergillus niger inoculant, namely (P0) control without fermentation, (P1) 1 x 107 CFU/g dry matter (DM) material, (P2) 3 x 107 CFU/g (DM) material, (P3) 6 x 107 CFU/g (DM) material and (P4) 9 x 107 CFU/g (DM) material, each treatment required 200 grams of tuberose flower waste.very significant (P<0.01) effect onnutritional content Polianthes tuberosa mfermented nature. The conclusion of the study was that the administration of Aspergillus niger at a dose of 9 x 107 CFU/g (DM) material was the best dose for Polianthes tuberosa fermentation with a content of 83,87±0,69 % organic matter, 11,50±0,01% crude protein, 0,31±0,08% CF, 18,62±0,23% crude fiber dan 69,57±0,18% non-nitrogen extract materials.

Ifit2 restricts murine coronavirus spread to the spinal cord white matter and its associated myelin pathology.

Interferon-induced protein with tetratricopeptide repeats 2, Ifit2, is critical in restricting neurotropic murine-β-coronavirus, RSA59 infection. RSA59 intracranial injection of Ifit2-deficient (-/-) compared to wild-type (WT) mice results in impaired acute microglial activation, reduced CX3CR1 expression, limited migration of peripheral lymphocytes into the brain, and impaired virus control followed by severe morbidity and mortality. While the protective role of Ifit2 is established for acute viral encephalitis, less is known about its influence during the chronic demyelinating phase of RSA59 infection. To understand this, RSA59 infected Ifit2-/- and Ifit2+/+ (WT) were observed for neuropathological outcomes at day 5 (acute phase) and 30 post-infection (chronic phase). Our study demonstrates that Ifit2 deficiency causes extensive RSA59 spread throughout the spinal cord gray and white matter, associated with impaired CD4+ T and CD8+ T cell infiltration. Further, the cervical lymph nodes of RSA59 infected Ifit2-/- mice showed reduced activation of CD4+ T cells and impaired IFNγ expression during acute encephalomyelitis. Interestingly, BBB integrity was better preserved in Ifit2-/- mice, as evidenced by tight junction protein Claudin-5 and adapter protein ZO-1 expression surrounding the meninges and blood vessels and decreased Texas red dye uptake, which may be responsible for reduced leukocyte infiltration. In contrast to sparse myelin loss in WT mice, the chronic disease phase in Ifit2-/- mice was associated with severe demyelination and persistent viral load, even at low inoculation doses. Overall, our study highlights that Ifit2 provides antiviral functions by promoting acute neuroinflammation and thereby aiding virus control and limiting severe chronic demyelination. IMPORTANCE Interferons execute their function by inducing specific genes collectively termed as interferon-stimulated genes (ISGs), among which interferon-induced protein with tetratricopeptide repeats 2, Ifit2, is known for restricting neurotropic viral replication and spread. However, little is known about its role in viral spread to the spinal cord and its associated myelin pathology. Toward this, our study using a neurotropic murine β-coronavirus and Ifit2-deficient mice demonstrates that Ifit2 deficiency causes extensive viral spread throughout the gray and white matter of the spinal cord accompanied by impaired microglial activation and T cell infiltration. Furthermore, infected Ifit2-deficient mice showed impaired activation of T cells in the cervical lymph node and relatively intact blood-brain barrier integrity. Overall, Ifit2 plays a crucial role in mounting host immunity against neurotropic murine coronavirus in the acute phase while preventing mice from developing viral-induced severe chronic neuroinflammatory demyelination, the characteristic feature of human neurological disease multiple sclerosis (MS).

Effects of Different Eimeria Inoculation Doses on Growth Performance, Daily Feed Intake, Gut Health, Gut Microbiota, Foot Pad Dermatitis, and Eimeria Gene Expression in Broilers Raised in Floor Pens for 35 Days.

The study was conducted to investigate the effects of different Eimeria inoculation doses on the growth performance, gut ecosystem, and body composition of broilers in floor pens for 35 days. A total of 750 15-day-old broilers were allocated to five experimental groups with six replicate pens. The five experimental groups included unchallenged control (CON); Eimeria dose 1 (ED1): E. acervulina: 31,250/E. maxima: 6250/E. tenella: 6250; Eimeria dose 2 (ED2): E. acervulina: 62,500/E. maxima: 12,500/E. tenella: 12,500; Eimeria dose 3 (ED3): E. acervulina: 125,000/E. maxima: 25,000/E. tenella: 25,000; and Eimeria dose 4 (ED4): E. acervulina: 250,000/E. maxima: 50,000/E. tenella: 50,000. On D 21, BW were linearly reduced by increased Eimeria inoculation doses (p < 0.01). On D 35, the Eimeria challenge groups had significantly lower BW compared to the CON group. Increased Eimeria inoculation doses linearly decreased crude fat (CF) (p < 0.01) on D 21. Increased Eimeria inoculation doses tended to increase the relative abundance of the phylum Proteobacteria (p = 0.098) on D 21. On D 35, lean:fat was linearly reduced by increased Eimeria inoculation doses (p < 0.05). Eimeria infection negatively influenced growth performance and gut health in broilers in the acute phase, and the negative effects were prolonged to D 35 in floor pen conditions.

Biotransformation of sulfamethoxazole by newly isolated surfactant-producing strain Proteus mirabilis sp. ZXY4: Removal efficiency, pathways, and mechanisms

In this study, the SMX degrading strain Proteus mirabilis sp. ZXY4 with surfactant manufacturing potential was isolated from sludge utilizing blood agar and CTAB agar plate. FTIR analysis indicated that the biosurfactant generated by strain ZXY4 was glycolipid. 3D-EEM demonstrated that SMX biodegradation was strongly connected to biosurfactants, the synergistic effect of biodegradation and biosurfactant made strain ZXY4 have excellent SMX degradation performance. Under the optimal conditions of inoculation dosage of 15%, temperature of 30 ℃, pH of 7 and initial SMX concentration of 5 mg L-1, strain ZXY4 could completely degrade SMX within 24 h. SMX biodegrades at low concentrations (less than5 mg L-1) followed by the zero-order kinetic model, high concentration (>5 mg L-1) is more consistent with the first-order kinetic model. LC-MS analysis revealed 14 SMX degradation intermediates, and five potential biodegradation mechanisms were postulated. The findings provide new insights into the biodegradation of SMX.

Polyclonal antibodies inhibit growth of key cellulolytic rumen bacterial species.

Antibodies targeting specific bacterial species could allow for modification of the rumen microbial population to enhance rumen fermentation. However, there is limited knowledge of targeted antibody effects on rumen bacteria. Therefore, our objective was to develop efficacious polyclonal antibodies to inhibit the growth of targeted cellulolytic bacteria from the rumen. Egg-derived, polyclonal antibodies were developed against pure cultures of Ruminococcus albus 7 (anti-RA7), Ruminococcus albus 8 (anti-RA8), and Fibrobacter succinogenes S85 (anti-FS85). Antibodies were added to a cellobiose-containing growth medium for each of the three targeted species. Antibody efficacy was determined via inoculation time (0 h and 4 h) and dose response. Antibody doses included: 0 (CON), 1.3 × 10-4 (LO), 0.013 (MD), and 1.3 (HI) mg antibody per ml of medium. Each targeted species inoculated at 0 h with HI of their respective antibody had decreased (P < 0.01) final optical density and total acetate concentration after a 52 h growth period when compared with CON or LO. Live/dead stains of R. albus 7 and F. succinogenes S85 dosed at 0 h with HI of their respective antibody indicated a decrease (≥ 96%; P < 0.05) in live bacterial cells during the mid-log phase compared with CON or LO. Addition of HI of anti-FS85 at 0 h in F. succinogenes S85 cultures reduced (P < 0.01) total substrate disappearance over 52 h by at least 48% when compared with CON or LO. Cross-reactivity was assessed by adding HI at 0 h to non-targeted bacterial species. Addition of anti-RA8 or anti-RA7 to F. succinogenes S85 cultures did not affect (P ≥ 0.45) total acetate accumulation after 52 h incubation, indicating that antibodies have less of an inhibitory effect on non-target strains. Addition of anti-FS85 to non-cellulolytic strains did not affect (P ≥ 0.89) OD, substrate disappearance, or total VFA concentrations, providing further evidence of specificity against fiber-degrading bacteria. Western blotting with anti-FS85 indicated selective binding to F. succinogenes S85 proteins. Identification by LC-MS/MS of 8 selected protein spots indicated 7 were outer membrane proteins. Overall, polyclonal antibodies were more efficacious at inhibiting the growth of targeted cellulolytic bacteria than non-targeted bacteria. Validated polyclonal antibodies could serve as an effective approach to modify rumen bacterial populations.

A novel rodent model of chronic spinal implant-associated infection

BACKGROUND CONTEXTBacterial infection of spinal instrumentation is a significant challenge in spinal fusion surgery. Although the intraoperative local application of powdered vancomycin is common practice for mitigating infection, the antimicrobial effects of this route of administration are short-lived. Therefore, novel antibiotic-loaded bone grafts as well as a reliable animal model to permit the testing of such therapies are needed to improve the efficacy of infection reduction practices in spinal fusion surgery. PURPOSEThis study aims to establish a clinically relevant rat model of spinal implant-associated infection to permit the evaluation of antimicrobial bone graft materials used in spinal fusion. STUDY DESIGNRodent study of chronic spinal implant-associated infection. METHODSInstrumentation anchored in and spanning the vertebral bodies of L4 and L5 was inoculated with bioluminescent methicillin-resistant Staphylococcus aureus bacteria (MRSA). Infection was monitored using an in vivo imaging system (IVIS) for 8 weeks. Spines were harvested and evaluated histologically, and colony-forming units (CFUs) were quantified in harvested implants and spinal tissue. RESULTSPostsurgical analysis of bacterial infection in vivo demonstrated stratification between MRSA and phosphate-buffered saline (PBS) control groups during the first 4 weeks of the 8-week infection period, indicating the successful establishment of acute infection. Over the 8-week chronic infection period, groups inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU demonstrated significantly higher bioluminescence than groups inoculated with PBS control (p = 0.009 and p = 0.041 respectively). Histological examination at 8 weeks postimplantation revealed the presence of abscesses localized to implant placement in all MRSA inoculation groups, with the most pervasive abscess formation in samples inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU. Quantification of CFU plated from harvested spinal tissue at 8 weeks post-implantation revealed the 1 × 105 MRSA CFU inoculation group as the only group with a significantly greater average CFU count compared to PBS control (p = 0.017). Further, CFU quantification from harvested spinal tissue was greater than CFU quantification from harvested implants across all inoculation groups. CONCLUSIONOur model demonstrated that the inoculation dosage of 1 × 105 MRSA CFU exhibited the most robust chronic infection within instrumented vertebral bodies. This dosage had the greatest difference in bioluminescence signal from control (p < 0.01), the lowest mortality (0% compared to 50% for samples inoculated with 1 × 106 MRSA CFU), and a significantly higher amount of CFUs from harvested spine samples than CFUs from control harvested spine samples. Further, histological analysis confirmed the reliability of this novel rodent model of implanted-associated infection to establish infection and biofilm formation of MRSA for all inoculation groups. CLINICAL SIGNIFICANCEThis model is intended to simulate the infection of instrumentation used in spinal fusion surgeries concerning implant locality and material. This model may evaluate potential antimicrobial and osteogenic biomaterials and investigate the relationship between implant-associated infection and failed fusion.

Bacillus velezensis SQR9 inhibition to fungal denitrification responsible for decreased N2O emissions from acidic soils

Tropical and subtropical acidic soils are hotspots of global terrestrial nitrous oxide (N2O) emissions, with N2O produced primarily through denitrification. Plant growth-promoting microbes (PGPMs) may effectively mitigate soil N2O emissions from acidic soils, achieved through differential responses of bacterial and fungal denitrification to PGPMs. To test this hypothesis, we conducted a pot experiment and the associated laboratory trials to gain the underlying insights into the PGPM Bacillus velezensis strain SQR9 effects on N2O emissions from acidic soils. SQR9 inoculation significantly reduced soil N2O emissions by 22.6–33.5 %, dependent on inoculation dose, and increased the bacterial AOB, nirK and nosZ genes abundance, facilitating the reduction of N2O to N2 in denitrification. The relative contribution of fungi to the soil denitrification rate was 58.4–77.1 %, suggesting that the N2O emissions derived mainly from fungal denitrification. The SQR9 inoculation significantly inhibited the fungal denitrification and down-regulated fungal nirK gene transcript, dependent on the SQR9 sfp gene, which was necessary for secondary metabolite synthesis. Therefore, our study provides new evidence that decreased N2O emissions from acidic soils can be due to fungal denitrification inhibited by PGPM SQR9 inoculation.

Untargeted metabolomic analysis reveals the mechanism of Enterococcus faecium agent induced CaCO3 scale inhibition.

In this study, a lactic acid bacterium, Enterococcus faecium, was found to prevent CaCO3 precipitation through its metabolism. On analysis of all stages of E. faecium growth, static jar tests demonstrated that stationary phase E. faecium broth possessed the highest inhibition efficiency of 97.3% at a 0.4% inoculation dosage, followed by the decline and log phases with efficiencies of 90.03% and 76.07%, respectively. Biomineralization experiments indicated that E. faecium fermented the substrate to produce organic acid, which resulted in modulation of the pH and alkalinity of the environment and thus inhibited CaCO3 precipitation. Surface characterization techniques indicated that the CaCO3 crystals precipitated by the E. faecium broth tended to be significantly distorted and formed other organogenic calcite crystals. The scale inhibition mechanisms were revealed by untargeted metabolomic analysis on log and stationary phase E. faecium broth. In total, 264 metabolites were detected, 28 of which were differential metabolites (VIP ≥ 1 and p < 0.05). Of these, 15 metabolites were upregulated in stationary phase broth, and 13 metabolites were downregulated in log phase broth. Metabolic pathway analysis suggested that improved glycolysis and the TCA cycle were the main reasons for enhancement of the antiscaling performance of E. faecium broth. These findings have significant implications for microbial metabolism-induced CaCO3 scale inhibition.

Enhancing the ability of rice to adapt and grow under saline stress using selected halotolerant rhizobacterial nitrogen fixer

Abstract Salinity stress has become the major devastating constraint for rice growth. Halotolerant rhizobacterial nitrogen fixer (HRNF) was investigated for increasing the nitrogenase activity (NA), organic acid (OA), gibberellic acid (GA), and indole 3-acetic acid (IAA) productions, seedling growth, and rice yield. Six N fixers were isolated using Ashby’s (Ab1, Ab2, and Ab3) and Okon’s media (Az1, Az2, and Az3). Furthermore, bioassay was carried out using rice seedling grown on nitrogen-free medium. The Ab3 and Az2 isolates were selected and biomolecularly identified as Pseudomonas stutzeri and Klebsiella pneumoniae, respectively. These selected bacteria were used as active ingredients for Halotolerant rhizobacterial inoculant (HRI) dosage trials (0, 500, 1,000, and 1,500 g ha−1) on simple pot experiments. The Az group isolates had 3–5 times higher ability in fixing N and producing OA, GA, and IAA than the Ab group isolates. Furthermore, N-uptake, number of panicles, filled grain, and the rice yield of HRI treated pots were significantly increased. Application of 1,000–1,500 g HRI ha−1 had resulted in a significant increase in the yield of rice grain (26.10–28.27 g plant−1 or 15.4–25.09%) which was higher than the control. This result concludes that HRI could contribute in enhancing the ability of rice to adapt and grow under saline stress.

New Method of Vaccination Against Anthrax

The aim of this work was to develop an oral method of vaccination against anthrax, since wide vaccination campaigns using this method require no special conditions, equipment, and instruments. Also, minimum number of medical personnel is sufficient to ensure control over the intake of the drug. Materials and methods. Domestic raw materials, consumables and reagents that passed the incoming inspection and met the requirements of State and industry standards, technical specifications, and the articles of the Pharmacopoeia were used for the work. Batches of anthrax vaccines based on Bacillus anthracis strain STI-1, manufactured at the Research Center (Kirov) of the “48th Central Research Institute” of the Ministry of Defense of Russia were put to the test. Results and discussion. The immunization schemes have been tested on animals, taking into account the features of the antigen. One of the crucial factors that determine the effectiveness of oral vaccination is the correct choice of the type and form of the oral anthrax vaccine administered enterally. It has been shown that in contrast to oral vaccines, the vaccine strain in enteral vaccines must be protected from the harmful effects of stomach contents. Thus, enteric-coated capsules coated with a shell that is resistant to the action of stomach acid were used for the study. The presented experimental data indicate that a single administration of the capsules with oral anthrax vaccine STI protects at least 70 % of laboratory animals from a highly virulent strain of the anthrax microbe and confirm the safety and non-reactogenicity of the drug. The developed laboratory technology makes it possible to obtain a finished product containing one inoculation dose of an oral vaccine for laboratory animals. So, a new method of vaccination has been designed. It is necessary to conduct preclinical and clinical trials to promptly introduce the oral administration of anthrax vaccine into medical practice as the simplest method for mass vaccination of humans.

Vibrio cholerae Invasion Dynamics of the Chironomid Host Are Strongly Influenced by Aquatic Cell Density and Can Vary by Strain.

Cholera has been a human scourge since the early 1800s and remains a global public health challenge, caused by the toxigenic strains of the bacterium Vibrio cholerae. In its aquatic reservoirs, V. cholerae has been shown to live in association with various arthropod hosts, including the chironomids, a diverse insect family commonly found in wet and semiwet habitats. The association between V. cholerae and chironomids may shield the bacterium from environmental stressors and amplify its dissemination. However, the interaction dynamics between V. cholerae and chironomids remain largely unknown. In this study, we developed freshwater microcosms with chironomid larvae to test the effects of cell density and strain on V. cholerae-chironomid interactions. Our results show that chironomid larvae can be exposed to V. cholerae up to a high inoculation dose (109 cells/mL) without observable detrimental effects. Meanwhile, interstrain variability in host invasion, including prevalence, bacterial load, and effects on host survival, was highly cell density-dependent. Microbiome analysis of the chironomid samples by 16S rRNA gene amplicon sequencing revealed a general effect of V. cholerae exposure on microbiome species evenness. Taken together, our results provide novel insights into V. cholerae invasion dynamics of the chironomid larvae with respect to various doses and strains. The findings suggest that aquatic cell density is a crucial driver of V. cholerae invasion success in chironomid larvae and pave the way for future work examining the effects of a broader dose range and environmental variables (e.g., temperature) on V. cholerae-chironomid interactions. IMPORTANCE Vibrio cholerae is the causative agent of cholera, a significant diarrheal disease affecting millions of people worldwide. Increasing evidence suggests that the environmental facets of the V. cholerae life cycle involve symbiotic associations with aquatic arthropods, which may facilitate its environmental persistence and dissemination. However, the dynamics of interactions between V. cholerae and aquatic arthropods remain unexplored. This study capitalized on using freshwater microcosms with chironomid larvae to investigate the effects of bacterial cell density and strain on V. cholerae-chironomid interactions. Our results suggest that aquatic cell density is the primary determinant of V. cholerae invasion success in chironomid larvae, while interstrain variability in invasion outcomes can be observed under specific cell density conditions. We also determined that V. cholerae exposure generally reduces species evenness of the chironomid-associated microbiome. Collectively, these findings provide novel insights into V. cholerae-arthropod interactions using a newly developed experimental host system.

Vegetative and productive characteristics of soybean under doses of boron and inoculation of Trichoderma atroviride

The application of new management techniques with the objective of implementing in agriculture, such as the use of growth-promoting and/or plant-protecting microorganisms and micronutrients, appears as an alternative. Thus, the aim of the study was to evaluate the potential of Trichoderma atroviride in association with doses of B, analyzing the effects on nutritional contents, yield components and productivity. The study was carried out in the field, in a randomized block design in a 4 × 5 factorial scheme, whose treatments were combined, consisting of foliar application of T. atroviride in three phenological stages (V5, R1 and R5) and no application (SEM), and five doses of B (0, 500, 1000, 1500 and 2000 g ha-1). The data obtained were submitted to ANOVA and, when significant, the study of polynomial regression and Tukey’s test was carried out, followed by Pearson’s linear correlation analysis (p < 0.05). The use of the microorganism and doses of B did not result in a significant increase in the growth and productive yield of soybean (Glycine max (L.) Merr.), but the application of the micronutrient significantly increased the number of pods per plant and the foliar content of B. Positive correlations were observed between plant height and pod insertion height (r = 0.51***), pod with branches (r = 0.68***), grains with branches and pod (r = 0.69*** and 0.95*** respectively), as well as a negative correlation between 100-grain mass and plant height (r = -0.24*), and a non-correlation for yield and leaf content of B.

GAS-STING signaling plays an essential pathogenetic role in Doxorubicin-Induced Cardiotoxicity

BackgroundThe severe unfavorable effects of doxorubicin on the heart restrict its clinical usage. Numerous investigations document that cyclic GMP-AMP synthase (cGAS) activator of interferon genes (STING) cascade influences inflammation along with the immune response in a variety of diseases. The pathophysiological function of the cGAS-STING cascade in Doxorubicin-induced cardiomyopathy (DIC) is, nevertheless, unknown.MethodsIn vivo, cardiotoxicity was triggered by a single dose of intra-peritoneal inoculation of doxorubicin (15 mg/kg) in wild-type C57BL/6J mice and STING knockdown animals. Adeno-associated virus 9 (AAV9) was utilized to silence STING. qPCR along with Western blotting were adopted to assess alterations in the cGAS/STING cascade. To assess cardiac function, we employed echocardiography coupled with histology, as well as molecular phenotyping. In vitro, HL-1 cardiomyocytes were introduced as test models.ResultsIn wild type mice, doxorubicin stimulation significantly activated the cGAS/STING pathway. STING silencing increased rate of survival along with heart function in mice, as well as diminished myocardial inflammatory cytokines along with apoptosis. These observations were also confirmed by utilizing siRNA of STING in vitro studies.ConclusionThis research premise established that STING inhibition could alleviate Dox-triggered cardiotoxicity in mice. As a result, preventing DIC by repressing STING in cardiomyocytes might be a possible treatment approach.

Efficient removal of hexavalent chromium from water by Bacillus sp. Y2-7 with production of extracellular polymeric substances

ABSTRACT Bioremediation is an environmentally friendly technology for the treatment of chromium-contaminated sites. Here, a hexavalent chromium [Cr(VI)]-resistant strain was isolated from oil-contaminated soil and designated as Bacillus sp. Y2-7 based on 16S rDNA sequence characterization. The effects of various factors including inoculation dose, pH value, glucose concentration, and temperature on Cr(VI) removal rates were then evaluated. Based on the response surface methodology, optimal Cr(VI) removal efficiency (above 90%) could be achieved at an initial Cr(VI) concentration of 155.0 mg·L−1, glucose concentration of 11.479 g·L−1, and pH of 7.1. The potential removal mechanisms of Cr(VI) by strain Y2-7 were also supposed. The contents of polysaccharide and protein in extracellular polymer (EPS) of strain Y2-7 decreased slowly after cultured with Cr(VI) of 15 mg·L−1 from 1 to 7 days. We thus inferred that EPS bonded with Cr(VI) and underwent morphological changes in water. Molecular operating environment (MOE) analysis suggested that macromolecular protein complexes in Bacillus sp. Y2-7 and hexavalent chromium could establish hydrogen bonds. Collectively, our findings indicate that Bacillus sp. Y2-7 is an excellent bacterial candidate for chromium bioremediation.

Study on the pathogenicity, immunogenicity, endogenous development and drug sensitivity of Eimeria kongi.

Following the discovery of Eimeria kongi, we investigated the pathogenicity, immunogenicity, endogenous development and drug sensitivity of this coccidian. Coccidia-free rabbits were inoculated with 1 × 102 to 5 × 104 sporulated oocysts of E. kongi before challenge 14 days post inoculation. E. kongi was moderately pathogenic and induced good immunity against re-infection. All inoculated doses results in reduced food intake and body weight gain, and an inoculation oocyst dose of 1 × 103 or higher caused various degrees of diarrhea. Except for one death of the highest dose group, all rabbits recovered 12 days post inoculation. An inoculation dose of 1 × 103 or 1 × 104 oocysts conferred the most effective protection from re-infection, which reduced oocyst output by approximately 99% and maintained body weight gain. Four generations of schizogony were observed, and the endogenous development mainly occurred in the jejunum and ileum of rabbits. E. kongi was most sensitive to sulfachloropyrazine sodium, followed by decoquinate; it is resistant to diclazuril. Both decoquinate and sulfachloropyrazine sodium may be effective in the control of E. kongi infection.

Effect of mycorrhizae on phosphate fertilization efficiency and maize growth under field conditions

Phosphorus (P) is a plant macronutrient that is indispensable for maize (Zea mays L.) production. However, P is difficult to manage in weathered soils, and its fertilization practice has low efficiency because it becomes unavailable for absorption by plant roots. Symbiosis of plants with arbuscular mycorrhizal fungi increases plant growth and enhances P uptake from the soil that is not directly available to the roots. Thus, the objective of this study was to determine how inoculation with Rhizophagus intraradices and phosphate fertilization interacts and influences the development and productivity of second-crop maize. The experiment was conducted in Selvíria, Mato Grosso do Sul, Brazil, in 2019 and 2020, both in a Typic Haplorthox. A randomized block design in subdivided plots was used for the phosphate application during crop sowing (0, 25, 50, 75, and 100% concentrations of the recommended level), and the secondary treatments were the doses of mycorrhizal inoculant (0, 60, 120 and 180 g ha−1) applied to the seed using a dry powder inoculant containing 20,800 infectious propagules per gram of the arbuscular mycorrhizal fungus R. intraradices. Only in the first year of the experiment, inoculation and phosphate fertilization promoted benefits to the maize crop, indicating potential to increase yield.

RESPONSE OF BIOFERTILIZER IN CONJUNCTION WITH DIFFERENT LEVELS OF INORGANIC FERTILIZER IN CAULIFLOWER (BRASSICA OLERACEA VAR. BOTRYTIS) PRODUCTION AT CHITWAN, NEPAL

The crop growth with its yield and yield-attributing character of Kathmandu local variety of cauliflower was evaluated under different levels of the recommended dose of inorganic fertilizer and bio-fertilizer inoculation at Khairahani, Chitwan during the winter season from December 2021 to February 2022. The experiment was laid out into two factorial Randomized Complete Block Design with three different levels of NPK (Viz:100% NPK-120:60:50, 75% NPK-90:45:37.5, and 50% NPK-60:30:25) and bio-fertilizer (Viz: No inoculation, Azotobacter inoculation, VAM inoculation, and Azotobacter +VAM inoculation). The treatments were replicated thrice. Azotobacter was inoculated by dipping seedlings into 10% (V/V) solution for 30 minutes whereas, VAM was inoculated at the rate of 4 Kg ha-1 by soil application. The results revealed that significantly higher plant height (50.57cm), number of leaves (13.42), plant spread (55.60cm), leaf area index (2.41) at harvest, and days to 100% curding (77.62), curd weight (265.6 gm), curd diameter (26.10 cm) and marketable curd yield (8.41ton ha-1) was recorded under 100% NPK fertilizer. Regarding bio-fertilizer, inoculation with Azotobacter + VAM recorded significantly higher plant height (49.15 cm), number of leaves (14.22), leaf area index (2.51), plant spread (57.52 cm) at harvest, days to 50% curding (70.22), days to 100% curding (77.6), curd diameter (25.72 cm), curd weight (249.1 gm) and marketable curd yield (8.11-ton ha-1) as compared to that of the treatment with no inoculation. Interaction between the inorganic fertilizer and biofertilizer was seen as significant in plant height at 30 days after transplanting. Thus, it can be suggested that the application of a 100% recommended dose of NPK fertilizer and Azotobacter + VAM inoculation enhances the production of cauliflower.