Causative Research Articles

Virulome and phylogenomic profiling of a novel Burkholderia pseudomallei strain from an Indian clinical isolate.

Highly pathogenic Burkholderia pseudomallei is the causative agent of melioidosis, a neglected tropical disease endemic in Southeast Asian tropical region. This bacterium encompasses diverse virulence factors which further undergo dynamic gene-expression flux as it transits through distinct environmental niches within the host which may lead to manifestation of differential clinical symptoms. B. pseudomallei, is classified as a Tier 1 select agent in the United States and regarded as a risk group 3 organism in India with the potential to be used as bioweapon. Considering these facts, it is vital to uncover both physiological and genetic heterogeneity of B. pseudomallei, particularly to identify any novel virulence factors that may contribute to pathogenicity. B. pseudomallei strain CM000113 was isolated from a clinical case in India, characterized it for its physiological, biochemical, and prominently genetic traits through WGS. It has a type 2 morphotype with faster doubling time and high biofilm producing capacity as compared to Pseudomonas aeruginosa. The genome size is 7.3 Mbp and it is phylogenetically close to B. pseudomallei strain Mahidol 1106a and Burkholderia mallei Turkey 2. We observed genetic heterogeneity, as key virulence factors that were identified shows sequence dissimilarity with reference strains. Additionally, presence of genomic islands, harbouring two virulence factors, GmhA and GmhB2, associated with pathogenesis indicates possibility of horizontal gene transfer. These results emphasize the need for an extensive study focusing the genome of B. pseudomallei and its associated heterogeneity, to identify molecular biomarkers aiding to develop point-of-care diagnostic kits for early diagnosis of melioidosis.

Limited Variation in Bacterial Communities of Scaphoideus titanus (Hemiptera: Cicadellidae) Across European Populations and Different Life Stages

The Nearctic leafhopper Scaphoideus titanus (Hemiptera: Cicadellidae) is the primary vector of ‘Candidatus Phytoplasma vitis’, the causative agent of Flavescence doreé in Europe. Although microorganisms play an important role in the ecology and behavior of insects, knowledge about the interaction between S. titanus and microbes is limited. In this study, we employed an amplicon metabarcoding approach for profiling the V4 region of the 16S rRNA gene to characterize the bacterial communities of S. titanus across several populations from four European localities. Additionally, we investigated changes in bacterial communities between nymphal and adult stages. In total, we identified 7,472 amplicon sequence variants (ASVs) in adults from the European populations. At the genus level, ‘Candidatus Karelsulcia’ and ‘Candidatus Cardinium’ were the most abundant genera, with both being present in every individual. While we found significant changes in the microbial composition of S. titanus across different European populations, no significant differences were observed between nymphal and adult stages. Our study reveals new insights into the microbial composition of S. titanus and highlights the role of geography in influencing its bacterial community.

Case report: A rare case of meningoencephalitis caused by Mycobacterium gordonae

Meningoencephalitis, an infectious disease affecting the nervous system, is primarily caused by a variety of pathogens. Non-tuberculous mycobacteria (NTM) have emerged as the leading causative agent of infections worldwide, but central nervous system infections resulting from NTM are infrequent in individuals with functioning immune systems. This case report highlights the diagnosis and treatment of a 26-year-old female patient who developed headaches 2 months post double eyelid surgery and was subsequently diagnosed with NTM meningoencephalitis through metagenomic next-generation sequencing (mNGS) analysis of cerebrospinal fluid. The patient underwent a comprehensive diagnostic and therapeutic protocol, resulting in a positive clinical outcome.

A New Method for Feeding Laboratory-Reared Aedes aegypti (Diptera: Culicidae) Adult Females1

Abstract The mosquito Aedes aegypti (L.) (Diptera: Culicidae) transmits arboviruses including the causative agent for yellow fever and threatens human health in tropical and subtropical areas. To reduce the incidence of infection, a variety of tactics is being developed to keep the population density of this vector mosquito as low as possible. Laboratory research directed to this end requires maintaining laboratory colonies of the insect, which, in this case, requires providing immobilized live animals to A. aegypti adult females for a source of blood for production of viable eggs. Using live animals for this procedure is costly, time consuming, and requires rearing mammalian species in the laboratoy. This study evaluated the impact of supplying the adult females with blood from a domestic pig (Sus scrofa domestica L.) mixed with an anticoagulant (7 ml of heparin per liter of blood) on the oviposition rate of A. aegypti. Feeding A. aegypti females with pig blood obtained from a slaughter facility and mixed with heparin produced more eggs (6,994 ± 168) than those allowed to feed on a living hamster as a source of blood (5,483 ± 171). Thus, this methodology is more efficient and economical than the current use of live animals to feed females of A. aegypti.

Evaluating Alternative Fungicides for Effective Management of Rice Blast Disease: Inhibitory Effects on Pyricularia oryzae Cavara

Tricyclazole has been a successful solution for managing rice blast for over three decades. However, the continuous use of this fungicide has led to the development of resistance and the accumulation of tricyclazole residues within rice grains, prompting a ban on its usage in India. In response to this pressing issue, the present study aims to evaluate the efficacy of alternative fungicides in controlling the growth of Pyricularia oryzae, the causal agent of rice blast. The study employed a comprehensive approach, assessing the performance of various fungicides, including picoxystrobin, hexaconazole, isoprothiolane, kresoxim methyl, pyraclostrobin, tebuconazole, kitazin, and zineb, at varying dosage levels (100%, 75%, and 50% of the recommended dose). The findings of this investigation indicated that hexaconazole, isoprothiolane, kitazin, and zineb exhibited a 100% inhibition of P. oryzae growth across all tested doses. Pyraclostrobin also demonstrated a 100% inhibition at the highest dose, although its effectiveness decreased slightly at lower doses. In contrast, picoxystrobin and kresoxim methyl did not exhibit significant effectiveness in controlling the growth of the rice blast pathogen. These results provide valuable insights into the potential alternatives to tricyclazole for managing rice blast when used either alone or in combination at reduced doses.

Identification and Characterization of Bipolaris secalis and B. setariae Associated with Brown Stripe Disease on Saccharum officinarum in Yunnan, China.

Sugarcane (Saccharum officinarum L.) is the most important sugar crop that belongs to the Poaceae family and is mainly cultivated in tropical and subtropical regions worldwide. Brown stripe disease is a common and serious foliar fungal disease of sugarcane and has become a serious threat to sugarcane production in China. Yunnan Province is the second-largest sugar base in China. From 2022 to 2023, brown stripe-like symptoms from different sugarcane variety were observed in Yunnan. Thirty-nine Bipolaris-like isolates were obtained from symptomatic leaves of different sugarcane varieties and characterized by means of morphological identification combined with multilocus phylogeny comprising internal transcribed spacer rDNA (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the translation elongation factor-1α (TEF-1α) gene sequence date. The analysis provided strong support for the delineation and identification of two Bipolaris species associated with sugarcane brown stripe, including Bipolaris secalis and B. setariae. Pathogenicity text in potted sugarcane plants confirmed that these two Bipolaris species can cause brown stripe of sugarcane, thus fulfilling Koch's postulates. This study confirmed that B. secalis and B. setariae were the pathogens of brown stripe in Yunnan Province. To the best of our knowledge, this is the first to report B. secalis as causal agents of brown stripe of sugarcane. Collectively, this finding provides a basis for sugarcane brown stripe disease accurate diagnosis and would be helpful to the development of effective management strategies.

First Report of Leaf Blight on Paris polyphylla Caused by Ceratobasidium ramicola in China.

Paris polyphylla var. yunnanensisis a perennial herb with significant medicinal properties in anticancer, anti-inflammatory, antibacterial immunomodulatory and antispasmodic activities (Duan et al. 2018). In April 2022, leaf blight disease emerged in Xiangtan City (Hunan), affecting P. polyphylla plantings over an area of 3×104 m2 (27.904°N, 112.918°E). The disease incidence reached an average of 22% of the plants in the field, with infected plants initially displaying water-soaked chlorosis, followed by dry yellow shrinkage that gradually spread from the leaf tips to the entire plant. To identify the causal agent, 20 leaf lesions (4 mm2) collected from 20 plants were surface sterilized with 75% ethanol for 10 s, 5% NaOCl for 30 s, rinsed in sterile distilled water three times, transferred to potato dextrose agar (PDA) plates with lactic acid (0.125%) , and incubated at 28 °C in the dark. Four isolates (PP21 to PP24) with similar morphologies were obtained and purified by the hyphal-tip method. Colonies on PDA initially appeared white with cottony mycelium, later turning light-yellow on the underside. Septate hyphae were branched at right angles with a small constriction at the departure of the branch point and measured 4.16 to 7.93 µm in diameter. Binucleate cells within the septate hyphae were visualized using Giemsa staining (Servicebio, China). For molecular identification, the rDNA internal transcribed spacer (ITS), the second largest subunit of nuclear DNA-directed RNA polymerase II (RPB2), and ATP synthase subunit 6 (ATP6) were amplified from genomic DNA of the isolates extracted by Fungus Genomic DNA Extraction Kit (Bioflux, China) using primers ITS1/ITS4 (White et al. 1990), bRPB2-6F/bRPB2-7.1R (Matheny 2005; Reeb et al. 2004) and ATP61/ATP62 (Kretzer and Bruns 1999), respectively. The ITS, RBP2 and ATP6 of the four isolates were sequenced and deposited in GenBank. BLASTn search of sequenced ITS (PQ187050, PQ187051, PP728052, PQ187052), RBP2 (PQ202833, PQ202834, PP735921, PQ202835) and ATP6 (PQ202837, PQ202838, PP735922, PQ202839) revealed a >99% identity with the type strain of Ceratobasidium ramicola CBS133.82 (NR138368, DQ301708, and DQ301577). For phylogenetic analysis, concatenated sequences of ITS, RBP2, and ATP6 were employed using the maximum-likelihood method in MEGA-X. Based on the morphological and molecular analyses, the isolates were classified into the C. ramicola clade (Bandoni 1979; Samuels et al. 2012; Jeong et al. 2023). To test the pathogenicity of the isolate PP23, mycelial plugs (5 mm in diameter) were placed directly on 15 healthy leaves from 15 three-year-old plants after puncturing with sterile needles. Sterile PDA plugs served as controls. All plants were kept in a greenhouse with conditions of 25°C, 80% relative humidity and a photoperiod of 12 h. After 5 days, all infected plants developed leaf blight symptoms similar to those described above, whereas the control plants remained asymptomatic. The pathogenicity test was conducted three times. C. ramicolawas re-isolated from all symptomatic leaves and confirmed to be identical to the original isolate based on morphology and nucleotide sequences of ITS, RBP2, and ATP6. While C. ramicola is commonly reported to be isolated from diseased cacao, its pathogenicity to cacao remains unknown (Samuels et al. 2012). To our knowledge, this is the first report of C. ramicola causing leaf blight on P. polyphylla, a medicinal herb with significant economic importance in China.

MAGA Trumps the Incumbency Advantage in a Dueling Incumbent Primary

Redistricting is the causal agent responsible for two incumbents facing off in U.S. House elections and hence, despite the rarity of these matchups, they occur periodically due to district boundary changes. In this article, we examine who wins a recent and highly competitive incumbent duel: the 2024 GOP primary in Alabama’s congressional district (CD) 1. Our assessment of this race marks the first academic study to marshal large-N survey data for the purpose of gauging voter preferences in a dueling incumbent primary. This approach gives us a clearer understanding of what accounts for the outcome of a highly contentious and extremely close election. Our findings suggest the incumbency advantage was overridden by voter alignment with the MAGA wing of the Republican Party, which produced a narrow victory for the more MAGA/Trump-positioned candidate in this race.

Solanum pimpinellifolium exhibits complex genetic resistance to Pseudomonas syringae pv. tomato

Pseudomonas syringae pv. tomato (Pst) is the causal agent of bacterial speck disease in tomatoes. The Pto/Prf gene cluster from Solanum pimpinellifolium was introgressed into several modern tomato cultivars and provided protection against Pst race 0 strains for many decades. However, virulent Pst race 1 strains that evade Pto-mediated immunity now predominate in tomato-growing regions worldwide. Here we report the identification of resistance to a Pst race 1 strain (Pst19) in the wild tomato accession S. pimpinellifolium LA1589 (hereafter LA1589), using our rapid high-throughput seedling screen. LA1589 supports less bacterial growth than cultivars, and does not exhibit a hypersensitive response to Pst19. We tested an existing set of 87 Inbred Backcross Lines (IBLs) derived from a cross between susceptible Solanum lycopersicum E-6203 and Solanum pimpinellifolium LA1589 for resistance to Pst19. Using single-marker analysis, we identified three genomic regions associated with resistance. Bacterial growth assays on IBLs confirmed that these regions contribute to resistance in planta. We also mapped candidate genes associated with resistance in a cross between the Solanum lycopersicum var. lycopersicum cultivar Heinz BG-1706 and S. pimpinellifolium LA1589. By comparing candidates from the two mapping approaches, we were able to identify 3 QTL and 5 candidate genes in LA1589 for a role in resistance to Pst19. This work will assist in molecular marker-assisted breeding to protect tomato from bacterial speck disease.

Serological and bacterial prevalence of Brucella spp. in suspected patients: a risk factor analysis in North Khorasan, Iran

Background and Objectives: Brucellosis, a zoonotic bacterial disease caused by Brucella, affects humans and domestic animals, leading to significant economic loss. This study examined suspected cases in North Khorasan, Iran, to understand the prevalence of infection and its characteristics in this region. Materials and Methods: Blood specimens were collected from 200 patients suspected of brucellosis after obtaining in- formed consent. Serum samples were tested using RBPT, Wright, and 2-ME agglutination tests. Blood samples were cul- tured on Brucella agar, and positive cultures underwent biotyping and PCR assays. A questionnaire identified correlated risk factors. Results: RBPT, Wright, and 2-ME tests showed 25% brucellosis seroprevalence in symptomatic patients. In contrast, the prevalence was 2.5% among those with positive blood cultures. Notably, all culture-positive patients were also serologically positive, with titers exceeding 1:320 in Wright and 2-ME tests. Most positive cases were in people in their 30s, with B. mel- itensis biovar 1 identified as the causative agent, and the results were confirmed by multiplex PCR. Significant risk factors include contact with livestock and consumption of raw milk (P < 0.0001). Conclusion: The findings highlighted the importance of comprehensive diagnostic approaches for accurate identification of brucellosis. Furthermore, education regarding close contact with animals and pasteurization of dairy products is essential for controlling human brucellosis.

Toxoplasma gondii infection induces the expression of the chemokine CXCL16 in macrophages to promote chemoattraction of CXCR6+ cells.

CXCL16 is a multifaceted chemokine expressed by macrophages and other immune cells in response to viral and bacterial pathogens. However, few studies have investigated its role in parasitic infections. The obligate intracellular parasite Toxoplasma gondii (T. gondii) is the causative agent of toxoplasmosis, an infection with potentially deleterious consequences in immunocompromised individuals and the developing fetus of acutely infected pregnant women. Chemokines are critical mediators of host defense and, as such, dysregulation of their expression is a subversion strategy often employed by the parasite to ensure its survival. Herein, we report that types I and II T. gondii strains upregulated the expression of both transmembrane and soluble forms of CXCL16 in infected bone marrow-derived macrophages (BMDM). Exposure to soluble T. gondii antigens (STAg) and to excreted-secreted proteins (TgESP) led to the induction of CXCL16. Cxcl16 mRNA abundance and CXCL16 protein levels increased in a time-dependent manner upon T. gondii infection. Importantly, conditioned medium (CM) collected from T. gondii-infected wild-type (WT) macrophage cultures promoted the migration of RAW264.7 cells expressing CXCR6, the cognate receptor of CXCL16, an effect that was significantly reduced by a neutralizing anti-CXCL16 antibody or use of CM from CXCL16 knockout (KO) macrophages. Lastly, T. gondii-driven CXCL16 expression appeared to modulate cytokine-induced (IL-4 + IL-13) alternative macrophage activation and M2 phenotypic marker expression. Further investigation is required to determine whether this chemokine contributes to the pathogenesis of toxoplasmosis and to elucidate the underlying molecular mechanisms.

Optimising Transformation Efficiency in Borrelia: Unravelling the Role of the Restriction-Modification System of Borrelia afzelii and Borrelia garinii

Borrelia spp. are transmitted to humans by the bite of an infected tick. In Europe, Borrelia afzelii and Borrelia garinii are the main causative agents of Lyme borreliosis, one of the most prevalent tick-borne diseases in the northern hemisphere. In bacteria such as Borrelia spp., a restriction-modification system (RMS) protects against the harmful introduction of foreign DNA. The RMS comprises two activities: methyltransferase and endonuclease. This study is aimed to characterize the RMS of B. afzelii and B. garinii. First, we identified potential RMS genes. The predicted genes were cloned into a methylase-deficient Escherichia coli strain and digested with methylation-sensitive restriction enzymes to verify methyltransferase activity. Additionally, the RMS proteins were purified to evaluate endonuclease activity. Subsequently, methylated and unmethylated plasmids were used to investigate the effect of methylation on endonuclease activity and transformation efficiency. We identified four possible RMS genes in B. afzelii and four RMS genes in B. garinii. We analyzed the presence of these genes in patient isolates and observed a high degree of heterogeneity. The restriction pattern of DNA methylated by each of the four recombinantly expressed genes provided strong evidence that all encode adenine-specific methyltransferases. After 24 h of incubation with purified RMS proteins, we observed complete digestion of unmethylated plasmid DNA, demonstrating endonuclease activity. Finally, we proved that methylation protects against endonuclease activity and increases transformation efficiency.

Resistance of barley cultivars and accessions to pathotypes of the spot blotch causative agent

Background. The spot blotch disease caused by the hemibiotrophic fungus Bipolaris sorokiniana has become a serious problem for barley. Utilization of resistant or tolerant barley cultivars ensures sustainable diversity conservation and environmentfriendly crop production. Thus, supplying barley breeders with sources of resistance to harmful diseases is an urgent task. Materials and methods. A set of 100 barley accessions, earlier selected for different levels of resistance to B. sorokiniana, served as the material for this study. Eleven isolates of B. sorokiniana of various geographic origin, belonging to 4 pathotypes, were used for testing. The resistance of barley seedlings was assessed under controlled laboratory conditions, and that of adult plants under artificial infection pressure in the field. Responses to B. sorokiniana were scored using the 0–9 rating scale.Results and conclusions. Barley genotypes with race-specific resistance to the spot blotch causative agent were identified. The percentage of barley genotypes resistant to five isolates of B. sorokiniana pathotype 1 averaged 24.2%; two isolates of pathotype 3, 29.5%; three isolates of pathotype 7, 18.3%; and one isolate of pathotype 0, 37%. Barley accessions manifesting resistance in their seedlings, but susceptible in the phase of milk-wax ripeness, and vice versa, with seedling susceptibility and adult resistance, were identified. Six (6) barley genotypes showed seedling and adult resistance to pathotype 1, nine (9) to pathotype 3, and two (2) to pathotype 7. No barley accessions resistant to all isolates of the pathogen were found.

Molecular characterization and immunopathological investigation of Avian reticuloendotheliosis virus in breeder flocks in Egypt

BackgroundReticuloendotheliosis virus (REV) is an oncogenic immunosuppressive retrovirus that infects different kinds of avian species; posing significant economic losses to the poultry industry worldwide.MethodsIn Egypt, there is an unidentified disease associated with the runting-stunting syndrome with neoplasia, suspected to be REV, that has been continuously monitored in several breeder flocks. To diagnose and analyze REV by cell cultures, enzyme-linked immunosorbent assay (ELISA), histopathological investigation, the polymerase chain reaction (PCR) test, and sequencing analysis, 200 blood samples, and 50 tissue specimens were collected. The current study targets the occurrence and genetic characteristics of a viral neoplastic disease, resembling REV infection, circulating in breeder flocks from 2022 to 2023 in the Ismailia, El-Sharqia, and El-Dakahliya governorates.ResultHere, REV was isolated on chicken embryo fibroblast cell culture; exhibiting cell aggregation, rounding, and cell detachments. Collectively, only 70 serum samples were positive for anti‐REV antibodies with seroprevalence rates of 35% based on the ELISA test. The histopathological observation demonstrated lymphoreticular tumors in the liver, spleen, and other examined organs. The immunohistochemical staining method confirmed the REV-positive signals in all examined organs (liver, kidney, spleen, bursa, ovaries) except for the heart. The PCR assay of the LTR gene assessed 370 base pairs with only 5 positive samples with a percentage of 16.6%. Three positive samples were further sequenced and submitted to the Genbank under accession numbers (PP763709, PP763710, PP763711). Phylogenetic analysis of the REV-LTR gene showed that our three isolates (Sharquia-1-REV, Ismilia-2-REV, Mansoura-3-REV) are REV subtype III which predominantly circulated in breeders in Egypt. These three isolates are highest similar to American, Chinese, and Taiwanese REV reference strains, and other Egyptian strains with nucleotide identity percentages of 100%, 99%, and 99%; respectively, and on the amino acid identity level were with (99–100%), (98%, 99%), (99%, 100%); respectively.ConclusionsThis study established that REV infection was extensively distributed in the breeders and became one of the causes of the clinical outbreaks of tumors, raising awareness of REV as the causative agent of avian oncogenic disease in Egypt.

Space-time analysis, severity of the wilt disease in escabeche pepper (Capsicum baccatum var. Pendulum) and identification of the causal agent (Phytophthora capsici L.) under subtropical climate conditions in Peru

Phytophthora capsici is an aggressive pathogen in escabeche pepper on the Peruvian coast. Root rot has a strong correlation with humidity and environment. Disease behavior was evaluated epidemiologically using spatiotemporal variables. Severity was evaluated according to the advance of the secondary symptom according to grades 1 to 5. Then, coordinates of each plant were established by photogrammetric survey of a field with 1705 escabeche pepper plants. For temporal analysis, severity was adjusted to an exponential model (R2 = 0.909) and incidence to a Gompertz model (R2 = 0.921) that detected an initial delay of the disease due to temperature. For the spatial analysis, the Global Moran Index (Ii) showed a high spatial dependence of the disease reaching a peak of 0.4 and 0.7 for severity and incidence, respectively. Also, heat maps related to the Local Ii were generated from which an initial source of infestation was determined where the furrow irrigation started in random infestations. Then, the infestation spots were settled in areas of surface water accumulation. Also, rhizosphere samples were collected per plant by degree of severity on V8 or CMA whit PARB and PDA-A selective medium. As a result, significant differences were obtained between grade 1, grade 2, 3, 4 and grade 5. In addition, the effect on yield was significant for plants with grade 4 and 5 with respect to fruit weight (22.3 and 18.5g/fruit) and weight per plant (509.5 and 371.8g/plant), respectively.

Diagnostic Guide for Pythium Root Rot in Hydroponic Leafy Green and Herb Production

Pythium root rot is a ubiquitous disease of leafy greens and herbs in hydroponic systems. This disease is caused by multiple species of Pythium with P. aphanidermatum, P. dissotocum, P. myriotylum, and P. oopapillum most reported. This diagnostic guide is intended to inform growers and plant health professionals of the causal agent, host range, distribution, diagnostic approaches, and signs and symptoms of Pythium root rot in hydroponic systems.

Marginal bone resection and immediate internal fixation in multidrug resistant chronic septic nonunions of lower limb long bones: a case series.

This study aimed to evaluate the efficacy of a combined treatment approach integrating extensive debridement, immediate internal fixation, and the Masquelet technique for the management of infected nonunion of long bones in the lower limbs caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) bacteria. This retrospective case series was conducted at the Imam Khomeini Hospital Complex, Tehran, Iran, a tertiary-level academic referral centre. The study documented consecutive cases of patients presenting with infected nonunion of the tibia or femur, with a positive culture for MDR or XDR bacteria, treated between January 2019 and December 2022. Inclusion criteria were adults with a confirmed diagnosis of infected nonunion due to MDR or XDR bacteria, with exclusion criteria including patients with unrelated infections or allergies to the components of the treatment regimen. The primary outcomes measured were infection resolution and bone healing. The study cohort comprised 16 patients, predominantly male (87.5%) with an average age of 38.5 years. Methicillin-resistant Staphylococcus aureus (MRSA) was identified as the causative agent in 31.25% of the infections. Patients were followed for a period ranging from 12 to 26 months. The treatment protocol was uniformly applied across all cases. Successful bone union was observed in the majority of patients within 140 to 240 days following grafting. However, there were two instances where amputation was necessitated due to the failure to eradicate the infection. Complications arose in three cases during the follow-up period: two required re-debridement due to a recurrence of the infection, and one was subjected to bone transport owing to persistent nonunion. Notably, all cases that either failed or encountered complications were smokers. In this integrated approach, high rates of infection resolution and bone healing were achieved, suggesting this method as a viable option for these complex cases.

Development of a Therapeutic Agent Based on Escherichia coli, Assessment of Harmlessness and Anti-Radiation Activity

The paper presents the development, assessment of the safety and antiradiation activity of a therapeutic agent based on the culture of Escherichia coli strains “PL-6” and “KV-1”. To obtain the antiradiation agent, the causative agent of colibacillosis was grown in meat-peptone broth in a thermostat at a temperature of 37°C for 3 days. The grown suspension was centrifuged at 3000 rpm for 50 min, the supernatant was decanted. The sediment was brought to 1 billion cm3 with distilled water. Smears were prepared from the grown cultures and stained according to Gram to determine the purity and species of the grown culture. The prepared suspension was poured into sterile vials of 10, 50 or 100 cm3, sealed with rubber stoppers and rolled with aluminum caps, labeling with an indication of the strain, radiation dose and date. Irradiation of the microbial material was carried out on the γ-installation “Issledovatel”, source 60Co, absorbed dose rate of 1.028 Gy/sec, in the ranges of absorbed doses from 7.5 to 30.0 kGy with interdose intervals of 2.5 and 5.0 kGy. The degree of inactivation of γ-irradiated E. coli cultures was determined by seeding them on meat-peptone agar and thermostatting for 168 hours, recording the presence or absence of microorganism growth. The studies have established that the timing and degree of growth of irradiated E. coli cultures of the “PL-6” and “KV-1” strains are directly dependent on the radiation dose, their complete inactivation occurs with irradiation at a dose of 25.0 kGy. Further studies have shown that the developed biopreparation obtained on the basis of E. coli is sterile, areactogenic, non-toxic and harmless. The mechanism of formation of radioresistance of the organism against the background of application of antiradiation agents based on E. coli strains “PL-6” and “KV-1” consisted in restoration of hematological, biochemical and immune parameters, which contributed to preservation of 66.7 to 83.3٪ of lethally irradiated animals.

Comparative Analysis of the Neutralizing Capacity of Monovalent and Bivalent Formulations of Betuvax-CoV-2, a Subunit Recombinant COVID-19 Vaccine, Against Various Strains of SARS-CoV-2

SARS-CoV-2, the causal agent of the COVID-19 pandemic, is characterized by rapid evolution, which poses a significant public health challenge. Effective vaccines that provide robust protection, elicit strong immune responses, exhibit favorable safety profiles, and enable cost-effective large-scale production are crucial. The RBD-Fc-based Betuvax-CoV-2 vaccine has previously demonstrated a favorable safety profile and induced a significant anti-SARS-CoV-2 humoral immune response in clinical trials. Due to the rapid evolution and emergence of new SARS-CoV-2 strains, the relevance of bivalent vaccine formulations has increased. Methods: This study compared the neutralizing capacity of monovalent and bivalent vaccine formulations against different SARS-CoV-2 strains detected with a SARS-CoV-2 microneutralization assay (MNT). Findings: The monovalent Wuhan-based vaccine generated neutralizing antibodies against the Wuhan and Omicron BA.2 variants but not the distinct Omicron BQ.1 strain. Conversely, the monovalent BA.2-based vaccine induced neutralizing antibodies against both Omicron strains but not Wuhan. While the bivalent Wuhan and BA.2-based vaccine was effective against strains containing the same antigens, it was insufficient to neutralize the distinctive BQ.1 strain at a small dosage. Interpretation: These findings suggest that the vaccine composition should closely match the circulating SARS-CoV-2 strain to elicit the optimal neutralizing antibody response and include the appropriate dosage. Moreover, this study did not find additional advantages of using the bivalent form over the monovalent form for the vaccination against a single prevailing SARS-CoV-2 strain.

Fgk3, a Glycogen Synthase Kinase, Regulates Chitin Synthesis through the Carbon Catabolite Repressor FgCreA in Fusarium graminearum.

The glycogen synthase kinase-3 (GSK3) orthologs are well-conserved in eukaryotic organisms. However, their functions remain poorly characterized in filamentous fungi. In our previous study, we unveiled the function of Fgk3, the GSK3 ortholog, in glycogen metabolism in Fusarium graminearum, the causal agent of Fusarium head blight. Interestingly, the fgk3 mutant was unstable and tended to produce fast-growing suppressors, including secondary suppressors. Using whole-genome sequencing, we identified suppressor mutations in FgCHS5, FgFKS1, FgCREA, FgSSN6, FgRGR1, and FgPP2A in nine primary and four secondary suppressors. Subsequently, we validated that deletion of FgCHS5 or FgCREAΔH253 mutation partially suppressed the defects of fgk3 in vegetative growth and cell wall integrity, suggesting that Fgk3 may regulate the chitin synthesis through FgCreA-mediated transcriptional regulation in F. graminearum. Accordingly, the FGK3 deletion led to hyphal swelling with abnormal chitin deposition, and deletion of FGK3 or FgCREA caused the upregulation of the expression of chitin synthases FgCHS5 and FgCHS6. The interaction between Fgk3 and FgCreA was verified by Yeast two-hybrid and Co-Immunoprecipitation assays. More importantly, we verified that the nuclear localization and protein stability of FgCreA relies on the Fgk3 kinase, while the H253 deletion facilitated the re-localization of FgCreA to the nucleus in the fgk3 mutant background, potentially contributing to the suppression of the fgk3 mutant's defects. Intriguingly, the ΔH253 mutation of FgCreA, identified in suppressor mutant S3, is adjacent to a conserved phosphorylation site, S254, suggesting that this mutation may inhibit the S254 phosphorylation and promote the nuclear localization of FgCreA. Collectively, our findings indicate that the glycogen synthase kinase Fgk3 regulates the chitin synthesis through the carbon catabolite repressor FgCreA in F. graminearum.