Development of the first PCR for detection of Psoroptes ovis var. cuniculi infection and its comparison to microscopic examination and serological assay in rabbits

Psoroptes mites are the common ecto-parasites of wild and domestic animals worldwide, which causes considerable economic losses in livestock industry. Microscopy is deemed to be the 'gold standard' for the diagnosis of Psoroptes mite infection but it has poor sensitivity for low mite infections and/or sub-clinical infections. To overcome these shortcomings, we screened four genes to develop a sensitive and specific PCR for the detection of Psoroptes mite infection in rabbits, and confirmed its practicability in detecting early infection and monitoring treatment outcome with traditional microscopy and serological tests. Results showed that PCR assay targeting ITS2 (ITS2-PCR) had a high specificity and sensitivity (detection limit: 40.3 pg/μL DNA) for detecting P. ovis DNA. In rabbits artificially infected with P. ovis, all three diagnostic tests showed the same detection rate from 14 days post infection (dpi) to 42 days dpi. However, these diagnostic tests behave differently at 7 dpi and after treatment: at 7 dpi, the detection rate of ITS2-PCR was higher than rPsoSP3-based iELISA and traditional microscopy (ITS2-PCR: 88.9%, rPsoSP3-iELISA: 77.7%, microscopy: 33.3%); at 7 days post treatment (dpt), positivity rates of ITS2-PCR and microscopy rapidly decreased to 0.00% and 11.1%, whereas rPsoSP3-iELISA remained 100% positive rate. Furthermore, the comprehensive comparisons of diagnostic performance and features of three diagnostic tests at 7 dpi were performed. Compared to ITS2-PCR or rPsoSP3-iELISA, microscopy had the lowest sensitivity, and the agreement between these assays was low (κ < 0.3). Field study showed that ITS2-PCR showed a higher detection rate than microscopy (19.4% and 11.1%, respectively). Our results suggested that the ITS2-PCR developed in this study provided a new laboratory tool for diagnosis of P. ovis var. cuniculi infection, and it had advantages over microscopic examination in detection low-level mite infections and serological assay in monitoring treatment outcome.

[Progress of schistosomiasis control in People's Republic of China in 2022]

This report presented the endemic status of schistosomiasis and analyzed the data collected from the national schistosomiasis prevention and control system and national schistosomiasis surveillance program in the People's Republic of China in 2022. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to maintain the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan, Hubei, Anhui, Jiangxi and Hunan provinces maintained the criteria of transmission control by the end of 2022. A total of 452 counties (cites, districts) were found to be endemic for schistosomiasis in China in 2022, with 27 434 endemic villages covering 73 424 400 people at risk of infections. Among the 452 endemic counties (cities, districts), 75.89% (343/452), 23.45% (106/452) and 0.66% (3/452) achieved the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. In 2022, 4 317 356 individuals received serological tests for schistosomiasis, and 62 228 were sero-positive. A total of 208 646 individuals received stool examinations for schistosomiasis, with one positive and another two cases positive for urine microscopy, and these three 3 cases were imported schistosomiasis patients from Africa. There were 28 565 cases with advanced schistosomiasis documented in China by the end of 2022. Oncomelania hupensis snail survey was performed in 18 891 endemic villages in China in 2022 and O. hupensis snails were found in 6 917 villages (36.62% of all surveyed villages), with 8 villages identified with emerging snail habitats. Snail survey was performed at an area of 655 703.01 hm² and 183 888.60 hm² snail habitats were found, including 110.58 hm² emerging snail habitats and 844.35 hm² re-emerging snail habitats. There were 477 200 bovines raised in the schistosomiasis endemic areas of China in 2022, and 113 946 bovines received serological examinations for schistosomiasis, with 204 sero-positives detected. Among the 131 715 bovines received stool examinations, no positives were identified. In 2022, there were 19 726 schistosomiasis patients receiving praziquantel chemotherapy, and expanded chemotherapy was performed in 714 465 person-time for humans and 234 737 herd-time for bovines in China. In 2022, snail control with chemical treatment was performed at an area of 119 134.07 hm², and the actual area of chemical treatment was 65 825.27 hm², while environmental improvements were performed at an area of 1 163.96 hm². Data from the national schistosomiasis surveillance program of China showed that the mean prevalence of Schistosoma japonicum infections was both zero in humans and bovines in 2022, and no S. japonicum infection was detected in O. hupensis snails. These data demonstrated that the endemic status of schistosomiasis continued to decline in China in 2022, with 3 confirmed schistosomiasis patients that had a foreign nationality and all imported from Africa, and the areas of snail habitats remained high. Further improvements in the construction of the schistosomaisis surveillance and forecast system, and reinforcement of O. hupensis survey and control are required to prevent the re-emerging schistosomiasis.

Microfluidic synthesis of pH-responsive molecularly imprinted silica nanospheres for fluorescence sensing target glycoprotein

Here, fluorescent artificial antibodies for sensing ovalbumin in food were synthesized by molecular imprinting technique in a microfluidic reactor. A phenylboronic acid-functionalized silane was employed as the functional monomer to enable the polymer has pH-responsive property. Fluorescent molecularly imprinted polymers (FMIPs) could be produced continuously in a short time. Both fluorescein isothiocyanate (FITC) and rhodamine B isothiocyanate (RB)-based FMIPs can specifically recognize the target ovalbumin, particularly FITC-based FMIP, giving an imprinting factor of 2.5 and cross-reactivity factors of 2.7 (ovotransferrin), 2.8 (β-lactoglobulin) and 3.4 (bovine serum albumin), and was applied for the detection of ovalbumin in milk powder with recovery rates of 93-110%; moreover, the FMIP can be reused at least four times. Such FMIPs have promising future in replacing the fluorophore-labelled antibodies to fabricate fluorescent sensing devices or establish immunoassay methods, which have extra merits of low-cost, high stability and recyclability, easy to carry and store at ambient environments.

Synthesis of fluorescent artificial receptors with high specificity for simultaneous detection of non-steroidal anti-inflammatory drugs

Development of multiple detection methods to monitor non-steroidal anti-inflammatory drugs (NSAIDs) in food is an effective way to protect human health. Here, we aimed to synthesize fluorescent artificial receptors by molecular imprinting technique to construct a simultaneous detection system targeting NSAIDs. Rhodamine B and fluorescein-functionalized silanes were employed as the fluorescence signal reporters for naproxen and ketoprofen, respectively. Two fluorescent molecularly imprinted polymers (FMIPs) were obtained with high specificity, giving cross-reactivity factors of 6.4-15.8 (naproxen) and 2.6-25.6 (ketoprofen). Both FMIPs also displayed rapid response time (5 min) and high sensitivity (detection limit at ∼ nM level). A simultaneous detection system was constructed based on the FMIPs and applied for sensing the spiked NSAIDs in real samples, showing recoveries of 71-119 %, comparable with the HPLC methods (70-113 %). In summary, use of different FMIPs to construct simultaneous detection systems is practicable, and provides a flexible way for sensing multiple hazards in food samples.

[Clinical and pathological characteristics of gastric adenocarcinoma of fundic gland type]

To analyze the clinical, endoscopic and pathological feature of gastric adenocarcinoma of fundic gland type (GA-FG) (18 cases) collected from Sir Run Run Shaw Hospital, affiliated with Zhejiang University School of Medicine and Taizhou Hospital of Zhejiang Province from January 2019 to July 2022. There were 18 cases of patient of GA-FG, including male 12 cases, female 6 cases, aged from 38 to 78 years old, with average age of 60.5 years old. Gastroscopy showed that bulging or flat lesions of gastric fundus were 0.2-5.5 cm in size, and the mucosal surface was smooth, redness or rough. Histologic examination showed that tumor cells were dominated by chief cells and scattered with a few oxyntic cells, formed a complex gland that anastomoses each other, and infiltrated to the submucosa. The results of immunohistochemistry showed that tumor cells were positive for the expression of mucin-6 (MUC6) and Pepsinogen 1, and partial expression of synaptophysin (Syn). GA-FG is a rare type of gastric adenocarcinoma with good differentiation, and currently only a few cases have been reported, and often easily been misdiagnosed or missed. Therefore, to master the characteristics of clinic and pathology is helpful to improve the ability of clinical pathologists in differential diagnosis.

[Correction model of the sampling time error on the blood trough concentration of tacrolimus in non-sustained-release dosage form for renal transplant recipients]

Objective: To establish correction model of the sampling time error on the blood trough concentration of tacrolimus in non-sustained-release dosage form for renal transplant recipient and improve the accuracy of drug dose assessment and clinical adjustment in renal transplant recipients. Methods: Visit records of 206 outpatients in the Department of Transplantation, Nanfang Hospital, Southern Medical University were retrospectively collected from October 15, 2022 to October 30, 2022. The distribution of sampling time of tacrolimus blood drug concentration was described and the time range of correction was determined. Twenty inpatients after renal transplantation in the Department of Transplantation, Nanfang Hospital, Southern Medical University from October 1, 2022 to November 30, 2022 were prospectively included, and their demography data, laboratory test results during follow-ups, and CYP3A5 genotype were collected. The patients took tacrolimus in non-sustained-release dosage form every 12 h starting from 19∶30 on the day of admission. Peripheral blood samples were collected from the patients on the second day of admission at 7∶30 and on the third day at 6∶00-10∶00 every 30 minutes to test the blood concentration of tacrolimus. Using the collection time as the independent variable and the blood tacrolimus concentration as the dependent variable, a simple linear regression was performed to fitting a linear model of tacrolimus blood concentration-sampling time. Multiple linear regression was performed to analyze the influencing factors of the tacrolimus metabolic rate within a specific period and generate the regression equation. Results: The 206 outpatients aged (46±13) years, including 131 males (63.6%). The time gap [M (Q₁, Q₃)] between the sampling time of the follow-up outpatients and standard C₁₂ was 24 (13.0, 46.5) min, and the maximum time gap was 135 min. The 20 enrolled inpatients aged (45±12) years, including 15 males (75.0%). There was no significant difference in the blood concentration of tacrolimus collected at 7∶30 on the second (7.87±2.21)ng/ml and third days (7.84±2.33)ng/ml after admission of the enrolled inpatients (P=0.917), and the blood tacrolimus concentration rhythm was stable in the trial. The plasma concentration of C_10.5-C_14.5 was linearly related to the time, with R² [M (Q₁, Q₃)] 0.88 (0.85, 0.92) and all P<0.05. The metabolic rate of tacrolimus during C_10.5-C_14.5=0.984+0.090×basic concentration of tacrolimus (ng/ml)-0.036×body mass index+0.489×CYP3A5 genotype-0.007×hemolobin(g/L)-0.035×alanine aminotransferase (U/L)+0.143×total cholesterol (mmol/L)+0.027×total bilirubin (μmol/L), with R²=0.85. Conclusion: This study propose a correction model for tacrolimus (non-sustained-release dosage form) trough concentration around C₁₂, which is helpful for clinicians to easily and accurately assess renal transplant recipients' tacrolimus exposure.

[Preliminary study on the mechanism underlying the ecological isolation of Oncomelania hupensis populations in Changde City]

OBJECTIVE

To investigate ecological isolation between Oncomelania hupensis snail populations in hilly regions and marshland and lake regions in Yuanjiang valley, Changde City, Hunan Province, and to unravel its underlying mechanisms.

METHODS

Taoyuan County, Shimen County, Linli County and Lixian County in Changde City were selected as snail sampling sites in hilly regions, and Lixian County, Jinshi City, West Lake Administration District, Hanshou County and Dingcheng District were selected as snail sampling sites in marshland and lake areas. Cytochrome C oxidase 1 (cox 1) gene was amplified in snail samples and sequenced. The genetic sequences of O. hupensis snails were aligned using the software MEGA 11, and the haplotypes of O. hupensis snails were determined using the software DNASP 5.10.01. The phylogenetic tree was generated using Bayesian inference with the software MrBayes 3.2, and analysis of molecular variance (AMOVA) was performed to analyze the source of genetic divergence and estimate the genetic divergence index (F_ST) among snail populations with the software Arlequin 3.5.2.2. The genetic barrier among 11 O. hupensis snail populations was estimated using the Monmonier algorithm of adegenet toolkit in R package. The settings with "land in winter and water in summer" in the Yuanjian River section were divided into two categories according to the upstream and downstream, and the areas with "land in winter and water in summer" in the upstream and downstream were transformed into raster data, and then loaded into the software Fragstats 4 for analysis of landscape indicators. The trends in changes of digital elevation were extracted from the Yuanjiang River section based on the digital elevation model, and made three-dimensional visualization using the R package.

RESULTS

The mitochondrial cox 1 gene were amplified in 165 O. hupensis snais from 11 sampling sites and sequenced, and a total of 152 valid gene sequences were obtained, with 46 haplotypes or 9 populations determined. No haplotype was shared in snails between Taoyuan County and Dingcheng District and Hanshou County along the downstream of the Yuanjiang River. The total area of settings with "land in winter and water in summer" was 617.66 hm² in the upsteram of the Yuanjiang River, which consisted of 473 patches, with each patch measuring 1.31 hm², the largest area index of 0.735 2, the landscape division index of 0.999 9, and the landscape shape index of 45.293 7. The total area of settings with "land in winter and water in summer" was 9 956.92 hm² in the downstream of the Yuanjiang River, which consisted of 771 patches, with each patch measuring 12.91 hm², the largest area index of 97.839 9, the landscape division index of 0.042 7, and the landscape shape index of 7.249 6. The area of settings with "land in winter and water in summer" was much larger in the downstream than that in the upstream of the Yuanjiang River, and the stronger landscape connectivity and non-remarkable alteration of riverbed elevation provided suitable habitats for snail breeding.

CONCLUSIONS

The hydrological and environmental characteristics of the upstream of the Yuanjiang River restrain the breeding and spread of O. hupensis, resulting in ecological isolation between Oncomelania hupensis in Taoyuan County and those in the downstream of Yuanjiang River.

[Hypercapnia under controlled mechanical ventilation in patients with high-risk acute pulmonary thromboembolism]

Objective: To evaluate the variation of arterial partial pressure of carbon dioxide (PaCO₂) in patients with high-risk pulmonary embolism under mechanical ventilation. Methods: We retrospectively analyzed the cases of high-risk pulmonary embolism who underwent intravenous thrombolysis in Peking Union Medical College Hospital from January 1, 2012, to May 1, 2022. The enrolled patients were divided into a mechanical-ventilated group and an active-breathing group according to whether they received invasive mechanical ventilation or not. The level of PaCO₂ under active breathing between the two groups, the changes in PaCO₂ before intubation, after intubation and after thrombolysis in the mechanical-ventilated group were compared. The 14-day all-cause mortality of the two groups was calculated and compared. Results: A total of 49 patients with high-risk pulmonary embolism were enrolled, including 22 patients in the mechanical-ventilated group and 27 patients in the active-breathing group. Before intubation, PaCO₂ in both groups was lower than normal without statistically significant difference between the two groups. After effective thrombolysis therapy, PaCO₂ in both groups recovered to the normal range. In the mechanical-ventilated group, PaCO₂ significantly increased 11-147 min after intubation and returned to the normal range after thrombolysis therapy. The 14-day mortality in the mechanical-ventilated group was 54.5%, while all patients in the active-breathing group survived. Conclusions: Under mechanical controlled ventilation, patients with high-risk pulmonary embolism could represent hypercapnia which resolved after effective thrombolytic therapy. In mechanical ventilated patients with sudden-onset hypoxemia and hypercapnia, the possibility of high-risk pulmonary embolism should be considered.

Bio-Inspired Low-Cost Fabrication of Stretchable, Adhesive, Transparent, and Multi-Functionalized Joint Wound Dressings

Ideal joint wound dressings should not only promote wound healing and have good mechanical properties including stretchability and adhesion but also possess functions such as sterilization or motion monitoring. The multiple characteristic requirements have greatly limited the material's alternative, resulting in research on functional joint wound dressings falling far short of market demand. Therefore, low-cost, comprehensive designs need to be developed. Herein, inspired by the spiral arteries in the endometrium, alginate-based helical fibers were introduced into polyacrylamide/gelatin (PAM-Gel) to obtain composite polymer membranes, realizing a combination of both mechanical and functional properties. Large scale (100 m) and high-throughput (10 times higher than literature) fabrication of helical microfibers were first achieved, ensuring the low cost of fiber preparation. The composite film had adequate stretchability (>300% strain), adhesion strength (14 kPa), high transparency, and good biocompatibility. The helical fibers could be easily functionalized without affecting the mechanical properties of the dressings, thus broadening the range of materials available for joint dressings. After different treatments of the helical fibers, controlled drug release and joint motion monitoring were realized. Therefore, this helical microfiber composite membrane design achieved low-cost preparation, good mechanical properties, and functionalities including healing promotion, drug release, and motion monitoring ability, demonstrating application potential.

Relationship Between Mycotoxin Production and Gene Expression in Fusarium graminearum Species Complex Strains Under Various Environmental Conditions

The Fusarium graminearum species complex (FGSC) can produce various mycotoxins and is a major concern for food quantity and quality worldwide. In this study, we determined the effects of water activity (a_w), temperature, incubation time and their interactions on mycotoxin accumulation and the expression levels of biosynthetic genes in FGSC strains from maize samples in China. The highest deoxynivalenol (DON), 3-acetyldeoxynivalenol(3ADON) and 15-acetyldeoxynivalenol (15ADON) levels of the F. boothii and F. graminearum strains were observed at 0.98 a_w/30 °C or 0.99 a_w/25 °C. F. asiaticum and F. meridionale reached maximum nivalenol (NIV) and 4-acetylnivalenol (4ANIV) contents at 0.99 a_w and 30 °C. With the extension of the incubation time, the concentrations of DON and NIV gradually increased, while those of their derivatives decreased. F. boothii, F. meridionale and one F. asiaticum strain had the highest zearalenone (ZEN) values at 0.95 a_w and 25 °C, while the optimum conditions for the other F. asiaticum strain and F. graminearum were 0.99 a_w and 30 °C. Four genes associated with trichothecene and zearalenone synthesis were significantly induced under higher water stress in the early stage of production. The results indicated independence of mycotoxin production and gene expression, as maximum amounts of these toxic metabolites were observed at higher a_w in most cases. This study provides useful information for the monitoring and prevention of such toxins entering the maize production chain.

Phenylacetylglutamine as a novel biomarker of type 2 diabetes with distal symmetric polyneuropathy by metabolomics

PURPOSE

Type 2 diabetes mellitus (T2DM) with distal symmetric polyneuropathy (DSPN) is a disease involving the nervous system caused by metabolic disorder, while the metabolic spectrum and key metabolites remain poorly defined.

METHODS

Plasma samples of 30 healthy controls, 30 T2DM patients, and 60 DSPN patients were subjected to nontargeted metabolomics. Potential biomarkers of DSPN were screened based on univariate and multivariate statistical analyses, ROC curve analysis, and logistic regression. Finally, another 22 patients with T2DM who developed DSPN after follow-up were selected for validation of the new biomarker based on target metabolomics.

RESULTS

Compared with the control group and the T2DM group, 6 metabolites showed differences in the DSPN group (P < 0.05; FDR < 0.1; VIP > 1) and a rising step trend was observed. Among them, phenylacetylglutamine (PAG) and sorbitol displayed an excellent discriminatory ability and associated with disease severity. The verification results demonstrated that when T2DM progressed to DSPN, the phenylacetylglutamine content increased significantly (P = 0.004).

CONCLUSION

The discovered and verified endogenous metabolite PAG may be a novel potential biomarker of DSPN and involved in the disease pathogenesis.

Antifungal activities of a novel triazole fungicide, mefentrifluconazole, against the major maize pathogen Fusarium verticillioides

Fusarium ear rot (FER) is a serious fungal disease occurring the late growth stage of maize. FER not only reduces the yield of maize but also causes mycotoxin contamination, which affects the quality of maize and threatens human and animal health. Fusarium verticillioides is the predominant causative pathogen of FER worldwide. At present, there is no registered fungicide for use against maize FER in China. The novel isopropyl alcohol-triazole fungicide mefentrifluconazole (MFZ) has been shown to be effective against several Fusarium spp., but little is known about its specific activity against F. verticillioides. MFZ exhibited strong antifungal activities against 50 strains of F. verticillioides collected from the major maize-growing areas in China. MFZ inhibited mycelial growth, conidium production, germination and germ tube elongation of F. verticillioides. MFZ treatment significantly reduced fumonisin production and the expression levels of fumonisin biosynthetic genes. Genome-wide transcriptional profiling of F. verticillioides in response to MFZ indicated that the expression of genes involved in ergosterol biosynthesis, including fungicide target genes (cyp51 genes), was significantly downregulated by MFZ. MFZ treatment resulted in reduced ergosterol production and increased glycerol and malonaldehyde production as well as relative conductivity in F. verticillioides. A 2-year field experiment showed a significant reduction in FER severity in maize after spraying with MFZ at the tasseling stage. This study evaluated the potential of MFZ to control FER in maize and provides insights into its antifungal activities and mechanism of action against F. verticillioides.

[Lysosomal membrane protein Sidt2 knockout induces apoptosis of human hepatocytes in vitro independent of the autophagy-lysosomal pathway]

OBJECTIVE

To explore the regulatory mechanism of human hepatocyte apoptosis induced by lysosomal membrane protein Sidt2 knockout.

METHODS

The Sidt2 knockout (Sidt2^-/-) cell model was constructed in human hepatocyte HL7702 cells using Crispr-Cas9 technology.The protein levels of Sidt2 and key autophagy proteins LC3-II/I and P62 in the cell model were detected using Western blotting, and the formation of autophagosomes was observed with MDC staining.EdU incorporation assay and flow cytometry were performed to observe the effect of Sidt2 knockout on cell proliferation and apoptosis.The effect of chloroquine at the saturating concentration on autophagic flux, proliferation and apoptosis of Sidt2 knockout cells were observed.

RESULTS

Sidt2^-/- HL7702 cells were successfully constructed.Sidt2 knockout significantly inhibited the proliferation and increased apoptosis of the cells, causing also increased protein expressions of LC3-II/I and P62(P < 0.05) and increased number of autophagosomes.Autophagy of the cells reached a saturated state following treatment with 50 μmol/L chloroquine, and at this concentration, chloroquine significantly increased the expressions of LC3B and P62 in Sidt2^-/- HL7702 cells.

CONCLUSION

Sidt2 gene knockout causes dysregulation of the autophagy pathway and induces apoptosis of HL7702 cells, and the latter effect is not mediated by inhibiting the autophagy-lysosomal pathway.

Release of Interface Confined Water Significantly Improves Dentin Bonding

Water residue and replacement difficulty cause insufficient adhesive infiltration in demineralized dentin matrix (DDM), which produces a defective hybrid layer and thus a bonding durability problem, severely plaguing adhesive dentistry for decades. In this study, we propose that the unique properties of a highly hydrated interface of the porous DDM can give rise to 1 new type of interface, confined liquid water, which accounts for most of the residue water and may be the main cause of insufficient infiltration. To prove our hypothesis, 3 metal ions with increasing binding affinity and complex stability (Na⁺, Ca²⁺, and Cu²⁺) were introduced respectively to coordinate negatively charged groups such as -PO₄^3-, -COO^- abundant in the DDM interface. Strong chelation of Ca²⁺ and Cu²⁺ rapidly released the confined water, significantly improving penetration of hydrophobic adhesive monomers, while Na⁺ had little effect. A significant decrease of defects in the hybrid layer and a much decreased modulus gap between the hybrid layer and the adhesive layer greatly optimized the microstructure and micromechanical properties of the tooth-resin bonding interface, thus improving the effectiveness and durability of dentin bonding substantially. This study paves the way for a solution to the core scientific issue of contemporary adhesive dentistry: water residue and replacement in dentin bonding, both theoretically and practically.

Paralogous FgIDO genes with differential roles in tryptophan catabolism, fungal development and virulence in Fusarium graminearum

Indoleamine 2,3-dioxygenase (Ido) is a tryptophan-degrading enzyme that is widely distributed across species. Ido catalyzes the first step of tryptophan (TRP) degradation and drives the de novo synthesis of nicotinamide adenine dinucleotide (NAD⁺) coenzymes via the kynurenine (KYN) pathway. The budding yeast Saccharomyces cerevisiae possesses a single IDO gene (BNA2) that is responsible for NAD⁺ synthesis, whereas a number of fungal species contain multiple IDO genes. However, the biological roles of IDO paralogs in plant pathogens remain unclear. In the current study, we identified three FgIDOs from the wheat head blight fungus Fusarium graminearum. FgIDOA/B/C expression was significantly induced upon TRP treatment. Targeted disruption of FgIDOA and/or FgIDOB caused different levels of NAD⁺ auxotrophy, thus resulting in pleotropic phenotypic defects. Loss of FgIDOA resulted in abnormal conidial morphology, reduced mycelial growth, decreased virulence in wheat heads and reduced deoxynivalenol accumulation. Exogenous addition of KYN or various intermediates involved in the KYN pathway rescued auxotrophy of the mutants. Metabolomics analysis revealed shifts toward alternative TRP degradation pathways to melatonin and indole derivatives in mutants lacking FgIDOB. Upregulation of partner genes in auxotrophic mutants and the capacity to rescue the auxotroph by overexpressing a partner gene indicated functional complementation among FgIDOA/B/C. Taken together, the results of this study provide insights into differential roles in paralogous FgIDOs and how fungal TRP catabolism modulates fungal development and virulence.

[Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020]

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.

Effect of Abiotic Conditions on Growth, Mycotoxin Production, and Gene Expression by Fusarium fujikuroi Species Complex Strains from Maize

Fusarium fujikuroi species complex (FFSC) strains are a major concern for food quantity and quality due to their strong ability to synthesize mycotoxins. The effects of interacting conditions of water activity, temperature, and incubation time on the growth rate, toxin production, and expression level of biosynthetic genes were examined. High temperature and water availability increased fungal growth. Higher water activity was in favor of toxin accumulation. The maximum amounts of fusaric acid (FA) and fumonisin B1 (FB1) were usually observed at 20–25 °C. F. andiyazi could produce a higher content of moniliformin (MON) in the cool environment than F. fujikuroi. The expression profile of biosynthetic genes under environmental conditions varied wildly; it was suggested that these genes might be expressed in a strain-dependent manner. FB1 concentration was positively related to the expression of FUM1, while a similar correlation of FUB8 and FUB12 with FA production could be observed in F. andiyazi, F. fujikuroi, and F. subglutinans. This study provides useful information in the monitoring and prevention of such toxins entering the maize production chain.

Baseline clinical, hormonal and molecular markers associated with clinical response to IL-23 antagonism in hidradenitis suppurativa: A prospective cohort study

Hidradenitis suppurativa is a complex inflammatory disease in which predicting therapeutic response remains challenging. IL-23 interacts with sex hormones but the relationships between the two in HS remains uninvestigated. To assess whether baseline clinical, hormonal or molecular markers are associated with clinical response to IL-23 antagonism with risankizumab in hidradenitis suppurativa. Twenty six individuals with Hurley stage 2/3 disease were administered risankizumab 150 mg Week 0, 4, 12. Baseline sex hormones and skin biopsies were taken. Clinical response at Week 16 assessed by the HiSCR, and differences between responders and non-responders assessed. Eighteen of 26 participants achieved HiSCR50 at week 16 (69.2%). Clinical response to IL-23 antagonism was associated with male gender, elevated total serum testosterone and decreased levels of FSH. Stratification by clinical responders/nonresponders identified differentially expressed genes including PLPP4 and MAPK10. Immunohistochemistry identified elevated numbers of CD11c, IL-17A and IL-17F positive cells compared to nonresponders. CD11c + cells significantly correlated with serum levels of total testosterone and inversely correlated with serum FSH. Clinical response to IL-23 antagonism in HS is associated with serum sex hormones, Th17 polarized inflammation in lesional tissue and CD11c + cells. These potential therapeutic biomarkers require further validation in larger cohorts but may suggest potential targeted HS therapy.

First report of Rice panicle blight caused by Fusarium sporotrichioides in China

Rice (Oryza sativa L.) panicle blight, caused by various fungal and bacterial pathogens, is an emerging threat to rice production, due to the impact on rice yield and quality. In the autumn of 2020, a survey was conducted to understand the etiology of the disease in Liaoning province, an important rice growing area in northeastern China. Rice seeds with typical reddish or brown spots on the glumes were collected from various rice fields. Symptomatic seeds were sterilized with 5% sodium hypochlorite and 75% ethanol, rinsed in sterile distilled water, and placed on potato dextrose agar (PDA) plates. After 3 to 5 days of incubation at 25°C, suspected Fusarium strains showing cream to salmon colonies on PDA were purified by the single-spore isolation method. The identification of these strains were performed based on morphological and molecular characteristics. Fusarium incarnatum-equiseti species complex was the most frequently, followed by the members of Fusarium graminearum species complex and Fusarium fujikuroi species complex. However, one strain was identified as F. sporotrichioides Sherb. based on the following results: (I) Colonies on PDA produced dense mycelia and typical red pigment on the undersurface. Macroconidia were usually 3- to 5-septate, moderately curved to straight, and 27.46 ± 7.16 × 3.78 ± 0.8 μm (n = 50). Microconidia were ellipsoid to fusoid and 9.77 ± 2.29 × 2.99 ± 0.65 μm (n = 50). (II) Genomic DNA was extracted by AxyPrep Multisource Genomic DNA Miniprep Kit according to the manufacturer's instructions; the sequence analysis of partial translation elongation factor-1α (TEF-1α) and RNA polymerase II second largest subunit (RPB2) were accomplished with the primers EF1/2 and RPB5F/7CR, respectively. BLAST searches of the obtained sequences had 99-100% homology with several F. sporotrichioides strains from GenBank. DNA sequences of partial TEF-1α and RPB2 were deposited in GenBank as OQ068267 and OQ068269, respectively. (III) This strain can synthesis T-2, HT-2, diacetoxyscirpenol (DAS), and Neosolaniol (NEO) toxin at the concentration of about 5000, 600, 700 and 8000 μg/kg in rice culture, respectively, according to the previous culture and analysis methods (1,2). (IV) Pathogenicity tests were conducted with the rice variety Nanjing 9108 by spraying spore suspension (106 conidia/ml) on rice spikes (5 mL per spike) at the flowering stage. Control spikes were inoculated with sterile distilled water. Three weeks after inoculation, the inoculated rice glumes showed similar symptoms with the original samples in the field. No symptoms were observed on controls. Besides, F. sporotrichioides was successfully recovered from the inoculated rice spikes but not from controls. To our knowledge, this is the first report of F. sporotrichioides causing rice panicle blight in China and this disease appears to be a serious risk to food safety and human health. Funding: This work was supported by Jiangsu Agriculture Science and Technology (CX(21)1005). References: (1) J. J. Mateo et al. Int. J. Food Microbiol. 72:115, 2002. (2) J. Qiu et al. Plant Dis. 104:2193, 2020.