Establishment of a hydrodynamic delivery system in ducks.

Chronic hepatitis B virus (HBV) poses a significant global health challenge as it can lead to acute or chronic liver disease and hepatocellular carcinoma (HCC). To establish a safety experimental model, a homolog of HBV-duck HBV (DHBV) is often used for HBV research. Hydrodynamic-based gene delivery (HGD) is an efficient method to introduce exogenous genes into the liver, making it suitable for basic research. In this study, a duck HGD system was first constructed by injecting the reporter plasmid pLIVE-SEAP via the ankle vein. The highest expression of SEAP occurred when ducks were injected with 5 µg/mL plasmid pLIVE-SEAP in 10% bodyweight volume of physiological saline for 6 s. To verify the distribution and expression of exogenous genes in multiple tissues, the relative level of foreign gene DNA and ß-galactosidase staining of LacZ were evaluated, which showed the plasmids and their products were located mainly in the liver. Additionally, ß-galactosidase staining and fluorescence imaging indicated the delivered exogenous genes could be expressed in a short time. Further, the application of the duck HGD model on DHBV treatment was investigated by transferring representative anti-HBV genes IFNα and IFNγ into DHBV-infected ducks. Delivery of plasmids expressing IFNα and IFNγ inhibited DHBV infection and we established a novel efficient HGD method in ducks, which could be useful for drug screening of new genes, mRNAs and proteins for anti-HBV treatment.

Pulley Effect in the Capture of DNA Translocation through Solid-State Nanopores.

Nanopores are powerful single-molecule sensors for analyzing biomolecules such as DNA and proteins. Understanding the dynamics of DNA capture and translocation through nanopores is essential for optimizing their performance. In this study, we examine the effects of applied voltage and pore diameter on current blockage, translocation time, collision, and capture location by translocating λ-DNA through 5.7 and 16 nm solid-state nanopores. Ionic current changes are used to infer DNA conformations during translocation. We find that translocation time increases with pore diameter, which can be attributed to the decrease of the stall force. Linear and exponential decreases of collision frequency with voltage are observed in the 16 and 5.7 nm pores, respectively, indicating a free energy barrier in the small pore. Moreover, the results reveal a voltage-dependent bias in the capture location toward the DNA ends, which is explained by a "pulley effect" deforming the DNA as it approaches the pore. This study provides insights into the physics governing DNA capture and translocation, which can be useful for promoting single-file translocation to enhance nanopore sensing.

Comparison of Lumbar Fusion Surgical Outcomes Between Patients with Lumbar Spinal Stenosis ≥80 Versus 65-79 Years Old.

BACKGROUND The efficacy of lumbar fusion surgery in patients age 80 years and older with lumbar spinal stenosis (LSS) is still controversial. This retrospective study aimed to evaluate the surgical outcomes of LSS patients ³80 vs 65-79 years. MATERIAL AND METHODS The study included 66 patients diagnosed with LSS from 2014 to 2020; 33 patients were ³80 years and 33 patients were 65-79 years. The 2 groups were matched for sex and surgical segment. All patients underwent posterior lumbar decompression, fixation, and fusion surgery. The Numerical Rating Scale (NRS) of leg and back pain, Oswestry Disability Index (ODI), Short-Form Health Survey (SF-36), and radiographic data were collected before surgery and at 3, 6, and 12 months postoperatively. RESULTS NRS (back) in the ≥80 years group was significantly higher than in the 65-79 years group at 3 months [2 (0-3) vs 1 (0-3), P=0.001]. Improvement of SF-36 (3 months: 15.7±4.9 vs 27.6±5.4, P<0.001; 6 months: 27.3±6.8 vs 31.5±5.6, P=0.011) and Physical Component Score (PCS) (3 months: 6.5±2.5 vs 17.0±3.6, P<0.001; 6 months: 15.9±3.4 vs 20.1±3.1, P<0.001) at 3 and 6 months in the ≥80 years group were significantly smaller than in 65-79 years group. There was a difference of Pfirrmann index of adjacent segment disc between the 2 groups at 12 months [≥80 vs 65-79 years group: 5.5 (4-8) vs 5 (3-8), P=0.003]. CONCLUSIONS Lumbar fusion surgery in patients ≥80 years with LSS can provide comparable improvements in clinical and radiographic outcomes compared with younger patients. Postoperative physiological function recovery was slower in patients ≥80 years.

A rare discal cyst with concurrent double-level isthmic lumbar spondylolisthesis: a case report and literature review.

We presented a 47-year old male diagnosed as a discal cyst with concurrent isthmic lumbar spondylolisthesis, which was not reported in the literature previously. A cystectomy with two-segmental transforaminal lumbar interbody fusion and instruments was performed. The association between concurrent discal cyst and isthmic spondylolisthesis may be illuminated by excessive strain and focal degeneration of the disc. Preoperative discography is probably unnecessary when surgical resection and histopathology are indicated for the patient.

Inhibition of RhoA/MRTF-A signaling alleviates nucleus pulposus fibrosis induced by mechanical stress overload.

PURPOSE/AIM: : Intervertebral disc degeneration (IDD) is the leading cause of lower back pain, and clinically useful drugs for IDD are unavailable. Mechanical stress overload-induced fibrosis plays a critical role in IDD. RhoA/MRTF-A signaling is known to regulate tissue fibrosis; however, the effect of RhoA/MRTF-A on the development of IDD is unclear. MATERIALS AND METHODS: : The expression of aggrecan, collagen I, collagen II, MMP-12, CTGF, and MRTF-A in nucleus pulposus (NP) samples from IDD patients and controls was detected by immunohistochemical staining. Primary nucleus pulposus cells (NPCs) were isolated and cultured to establish an overload strain model treated with or without CCG-1423. The protein levels of RhoA, ROCK2, MRTF-A, CTGF, and MMP-12 as well as fibrosis-associated proteins were detected by western blotting and immunofluorescence. RESULTS: : Collagen I, MMP-12, and CTGF were significantly upregulated, and aggrecan and collagen II were significantly downregulated in the IDD samples. The cellular localization of MRTF-A was associated with intervertebral disc (IVD) degeneration. Overloaded strain enhanced the nuclear translocation of MRTF-A and changed the NPC morphology from spindle-shaped to long strips. Additional experiments showed that RhoA, ROCK2, MRTF-A, SRF, MMP-12, and CTGF were upregulated; however, aggrecan and collagen II were downregulated in NPCs under overload strain. CCG-1423, a RhoA/MRTF-A pathway inhibitor, reversed strain-induced fibrosis. CONCLUSION: : Mechanical stress activates RhoA/MRTF-A signaling to promote extracellular matrix (ECM) degeneration in the NP, which is associated with the development of IDD. Our findings suggest that the RhoA/MRTF-A inhibitor CCG-1423 can alleviate NPC degeneration caused by overload stress and has potential as a therapeutic agent for IDD.

Application of electromagnetic navigation in endoscopic transforaminal lumbar interbody fusion: a cohort study.

STUDY DESIGN: Clinical retrospective cohort study. OBJECTIVES: To explore the application of the electromagnetic navigation system in Endo-TLIF. MATERIALS AND METHODS: From May 2019 to March 2020, 76 patients with single-segment lumbar spondylolisthesis treated by electromagnetic navigation-assisted Endo-TLIF (NE group) and conventional Endo-TLIF (CE group) were enrolled in the study. Time of pedicle screw implantation, entire operation time, the number of intraoperative X-ray fluoroscopy exposures, total blood loss, incision length, ambulation time, accuracy of pedicle screws, complications, visual analog scale for back and leg pain, Oswestry Disability Index, Japanese Orthopedic Association score and postoperative fusion rates were recorded, respectively. RESULTS: There were no significant differences in preoperative demographics between the NE and CE groups (P > 0.05). The mean number of intraoperative X-ray fluoroscopy exposures, guidewires insertion, entire operation time, total blood loss and adjustment rate of screws in the NE group were significantly less compared with the CE group (P < 0.05, respectively). There were no significant differences in clinical parameters between the two groups at different time points in the follow-up period (P > 0.05). There was no statistical difference in fusion rates between the two groups. In addition, one case of cage subsidence was observed after surgery in the CE group. CONCLUSION: Electromagnetic navigation systems could be applied throughout the entire surgical course and ameliorate the shortcomings of the conventional Endo-TLIF technique to reduce radiation exposure, improve accuracy, avoid repetitive operations and shorten surgery time and the required learning curve of the procedure. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Comparison of electromagnetic and optical navigation assisted Endo-TLIF in the treatment of lumbar spondylolisthesis.

Uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion (Endo-TLIF) with percutaneous pedicle screw fixation is a promising, minimally invasive method for the treatment of lumbar spondylolisthesis. However, repeated radiation exposure from X-rays and the steep learning curve remain to be improved.

Sequential endoscopic and robot-assisted surgical solutions for a rare fungal spondylodiscitis, secondary lumbar spinal stenosis, and subsequent discal pseudocyst causing acute cauda equina syndrome: a case report.

BACKGROUND: Fungal spondylodiscitis is a rare infectious disease. The secondary lumbar spinal stenosis and postoperative discal pseudocyst were even rarer. The surgical interventions were disputed, yet endoscopic and robot-assisted techniques may be helpful under different circumstances. CASE PRESENTATION: A 62-year-old female was diagnosed as infectious spondylodiscitis at the L4/5 level and a posterolateral endoscopic debridement was performed after invalid conservative therapy. Causative organism culture revealed a rare fungus, Candida tropicalis. A secondary spinal stenosis with refractory radiculopathy occurred almost 3 years after the first surgery and a successful endoscopic surgery was implemented aiming to decompress the nerve in a minimally invasive way. However, 2 months later, the patient manifested severe acute cauda equina syndrome and radiological examinations suggested a rare postoperative discal pseudocyst. A laminectomy followed by a pseudocystectomy was applied to achieve thorough decompression. An innovative double trajectory system (simultaneous traditional pedicle screw and cortical bone trajectory screw) accompanied by posterolateral fusion was designed and executed by the professional robot-assisted system. CONCLUSION: Endoscopic and robot-assisted techniques may provide alternative solutions for fungal spondylodiscitis and accompanied sequelae.

Relationship between hinge fracture and postoperative axial symptoms after cervical laminoplasty.

OBJECTIVE: To identify the clinical characteristics of fractured hinges after open-door cervical laminoplasty for cervical canal stenosis and explore the relationship between hinge fractures and axial symptoms. METHODS: This was a retrospective study of patients with cervical myelopathy who underwent open-door laminoplasty between November 2014 and November 2016 at the Affiliated Hospital of Qingdao University. Cervical CT scans were performed after surgery and the Takeuchi criteria were applied to evaluate the postoperative axial symptoms. RESULTS: Of 223 opened laminae in 67 patients, 67 laminae (30.0%) in 30 patients (44.8%) showed fracture. The frequency of hinge fractures was higher at C6 (53.7%). Forty-nine fractured laminae (73.13%) were non-displaced and 18 were displaced. At 3 months, 33 fractured laminae (49.3%) showed bony union on CT, and union rates were 86.6% and 91.0% at 6 and 12 months, respectively, indicating that the union rate was lower for displaced fractures than for non-displaced fractures. Among the 67 patients, 14 had axial symptoms: three of 37 (8.1%) patients without hinge fractures and 11 of 30 (36.7%) patients with hinge fractures. One year later, the hinge fractures were healed in 24/30 patients. Among the six unhealed patients, five still suffered from axial symptoms. The frequency of axial symptoms was higher in the patients with three or more hinge fractures (66.7%) than in the patients with only one (16.7%) or two (46.7%) hinge fractures. CONCLUSIONS: Patients with hinge fractures may have an increased risk for axial symptoms after open-door cervical laminoplasty. The frequency of axial symptoms decreases with fracture healing.

mNGS helped diagnose scrub typhus presenting as a urinary tract infection with high D-dimer levels: a case report.

BACKGROUND: Scrub typhus is caused by O. tsutsugamushi and spreads through mite larvae biting the skin. Classic symptoms of the disease are eschar and lymphadenopathy. Previous reports have revealed clinical manifestations of scrub typhus, including gastrointestinal symptoms, meningoencephalitis, ocular flutter, pneumonitis, acute respiratory distress syndrome, and acute kidney injury. However, cases of scrub typhus presenting as a urinary tract infection (UTI) with high D-dimer levels could be easily misdiagnosed when clinical attention is insufficient, resulting in difficulty in making a timely diagnosis of the infection. Metagenomics next-generation sequencing (mNGS) is a revolutionary and highly sensitive method that may help in diagnosing atypical cases, even when trace amounts of pathogens are present. CASE PRESENTATION: A 52-year-old female presented with a 10-day history of fever, chills, headache and myalgia. She was initially diagnosed with influenza at a local clinic. Various antibacterials were used on the 2nd-12th day onwards; however, her symptoms persisted and were followed by increased urination duration, frequency, urgency and dysuria for 2 days. Orientia tsutsugamushi was confirmed as the pathogen responsible for the infection through mNGS analysis of her blood samples from Day 13 onwards. The patient's temperature changed remarkably 24 h after the initiation of doxycycline. Over the next 48 h (i.e., Day 15 onwards), the patient showed clinical improvement. She recovered and was discharged from the hospital. CONCLUSIONS: Scrub typhus can present atypical clinical symptoms, such as UTIs, in a febrile patient. mNGS may be a useful method for identifying O. tsutsugamushi infection in patients with atypical clinical manifestations.

The technical feasibility and preliminary results of minimally invasive endoscopic-TLIF based on electromagnetic navigation: a case series.

BACKGROUND: Uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion (Endo-TLIF) with percutaneous pedicle screw fixation is a promising, minimally invasive method for the treatment of lumbar spondylolisthesis. However, repeated radiation exposure from X-rays and the steep learning curve remain to be improved. METHODS: This retrospective study explored the effects of electromagnetic navigation on improving Endo-TLIF with percutaneous pedicle screw fixation. Clinical information from 42 patients who had received Endo-TLIF with percutaneous pedicle screw fixation from May 2019 to November 2020 was analyzed retrospectively. The procedures were assisted under electromagnetic navigation. The rate of adjustment for guide wires, frequency of X-ray exposure, operative time, accuracy of pedicle screw location, and clinical outcomes were recorded. RESULTS: The mean follow-up for 42 patients was 11.9 ± 3.1 months. The mean age of the patients was 56.1 ± 9.26 years, with a female/male ratio of 25:17. According to postoperative CT scans and 3D reconstructions, the excellent and good rate of pedicle screws was 96.4%. The rate of adjustment for guide wires under the assistance of electromagnetic navigation was 1.78%, and the frequency of X-ray exposure was 8.27 ± 1.83. The operative time was 167.25 ± 28.16 min, including the duration of guide wire insertion (14.63 ± 5.45 min) and duration of decompression and cage placement (75.43 ± 13.97 min). The duration of hospitalization after operation was 2.59 ± 1.16 days. The preoperative VAS score was 7.51 ± 1.91, and the preoperative ODI was 82.42 ± 8.7%. At the last follow-up, the VAS score was 2.09 ± 0.59, and the ODI was 11.09 ± 3.2%. There were statistically significant improvements in the VAS score and ODI in all patients at the follow-up (p < 0.05). CONCLUSIONS: Electromagnetic navigation can provide accurate positioning and guidance in real time, which improves the surgical efficiency of percutaneous pedicle screw placement and endoscopic decompression in Endo-TLIF with reduced radiation exposures.

Lumbar spinal stenosis combined with obesity-induced idiopathic spinal epidural lipomatosis treated with posterior lumbar fusion: case report.

BACKGROUND: Spinal epidural lipomatosis is a rare cause of lumbar spinal stenosis. While conservative therapy is applicable for most of cases, surgical intervention is necessary for severe ones. This is the first time we apply this modified technique to this disease. CASE PRESENTATION: The case is a 53-year-old man. He is 175 cm tall and weighs 102 kg (body mass index 33.3 kg/cm2), presenting with low back pain and bilateral legs pain and numbness. Radiological examination showed severe lumbar spinal stenosis resulting from adipose hyperplasia, combined with hyperosteogeny and hypertrophy of ligaments, which are common etiological factors. Posterior decompression, internal fixation and a modified articular fusion technique was performed on this patient, and regular follow-up that up o 22 months showed outstanding clinical outcomes. CONCLUSIONS: A suitable style of posterior lumbar fusion should be considered to especially severe case with lumbar spinal stenosis and idiopathic spinal epidural lipomatosis.

TdIF1-LSD1 Axis Regulates Epithelial-Mesenchymal Transition and Metastasis via Histone Demethylation of E-Cadherin Promoter in Lung Cancer.

We have previously found that TdT-interacting factor 1 (TdIF1) is a potential oncogene expressed in non-small cell lung cancer (NSCLC) and is associated with poor prognosis. However, its exact mechanism is still unclear. The lysine-specific demethylase 1 (LSD1) is a crucial mediator of the epithelial-mesenchymal transition (EMT), an important process triggered during cancer metastasis. Here, we confirm that TdIF1 is highly expressed in NSCLC and related to lymph node metastasis through The Cancer Genome Atlas (TCGA) analysis of clinical samples. Silencing TdIF1 can regulate the expression of EMT-related factors and impair the migration and invasion ability of cancer cells in vitro. An analysis of tumor xenografts in nude mice confirmed that silencing TdIF1 inhibits tumor growth. Furthermore, we determined the interaction between TdIF1 and LSD1 using immunoprecipitation. Chromatin immunoprecipitation (ChIP) revealed that TdIF1 was enriched in the E-cadherin promoter region. The knockdown of TdIF1 repressed the enrichment of LSD1 at the E-cadherin promoter region, thereby regulating the level of promoter histone methylation and modulating E-cadherin transcription activity, ultimately leading to changes in EMT factors and cancer cell migration and invasion ability. The LSD1 inhibitor and TdIF1 knockdown combination showed a synergistic effect in inhibiting the growth, migration, and invasion of NSCLC cells. Taken together, this is the first demonstration that TdIF1 regulates E-cadherin transcription by recruiting LSD1 to the promoter region, thereby promoting EMT and tumor metastasis and highlighting the potential of TdIF1 as a therapeutic target for NSCLC.

LINC01121 induced intervertebral disc degeneration via modulating miR-150-5p/MMP16 axis.

BACKGROUND: Growing evidence indicates that Long noncoding RNAs contribute to cell differentiation, invasion, metabolism, proliferation and metastasis. However, the potential role of LINC01121 in progression of intervertebral disc degeneration (IDD) remains unclear. METHODS: LINC01121, matrix metalloprotease (MMP)-16 and miR-150-5p expression was determined by a quantitative-reverse transcriptase-polymerase chain reaction assay. Inflammatory cytokines level was measured by an enzyme-linked immunosorbent assay and cell counting kit-8 analysis was used to assess cell proliferation. MMP-16-specific binding with miR-150-5p was verified with a luciferase reporter assay. RESULTS: We noted that interleukin (IL)-1ß and tumor necrosis factor (TNF)-α treatment enhanced LINC01121 and MMP-16 expression in nucleus pulposus (NP) cells. LINC01121 was higher in IDD specimens compared to that in control specimens. Higher expression of LINC01121 was correlated with disc degeneration degree. Ectopic expression of LINC01121 enhanced cell proliferation and promoted ki-67, MMP-3 and ADAMTS5 expression and also suppressed collagen II expression in NP cells. We observed that overexpression of LINC01121 increased the secretion of three inflammatory cytokines, including IL-6, TNF-α and IL-1ß. We found that ectopic expression of LINC01121 decreased the miR-150-5p level in NP cells. Luciferase reporter data confirmed that MMP-16 was one direct target of miR-150-5p. Overexpression of miR-150-5p inhibited MMP-16 level and elevated the expression of LINC01121 enhanced MMP-16 level. We also found that MMP-16 was up-regulated in IDD specimens compared to that in control specimens. Higher expression of MMP-16 was correlated with disc degeneration degree. Interestingly, MMP-16 expression was positively related to LINC01121 in IDD specimens. Finally, overexpression of LINC01121 regulated cell growth, extracellular matrix degradation and inflammatory cytokine secretion via modulating MMP-16. CONCLUSIONS: our data suggested LINC01121 may be a new therapeutic target for IDD.

Aspergillus spondylitis: case series and literature review.

BACKGROUND: Spinal fungal infections, especially spinal Aspergillus infections, are rare in the clinic. Here, we introduce the clinical features, diagnosis, treatment, and prognoses of 6 cases of Aspergillus spondylitis. METHODS: We retrospectively analysed the complete clinical data of patients with Aspergillus spondylitis treated in our hospital from January 2013 to January 2020. RESULTS: Aspergillus fumigatus was isolated in 4 cases, and Aspergillus spp. and Aspergillus niger were isolated in 1 case each. All six patients reported varying degrees of focal spinal pain; one patient reported radiating pain, one patient experienced bowel dysfunction and numbness in both lower limbs, and three patients had fever symptoms. One case involved the thoracic spine, one case involved the thoracolumbar junction, and 4 cases involved the lumbar spine. Three patients were already in an immunosuppressed state, and three patients entered an immunosuppressed state after spinal surgery. All six patients were successfully cured, and five required surgery. Of the 5 patients who underwent surgical treatment, 2 had spinal cord compression symptoms, and 3 had spinal instability. At the end of follow-up, 1 patient reported left back pain and 1 patient reported left limb numbness. CONCLUSION: The clinical manifestations of Aspergillus spondylitis are non-specific, and the diagnosis depends on typical imaging findings and microbiological and histopathological examination results. When there is no spinal instability, spinal nerve compression symptoms, or progressive deterioration, antifungal therapy alone may be considered. If spinal instability, spinal nerve compression, or epidural abscess formation is present, surgery combined with antifungal therapy is recommended.

Long non-coding RNAs in the spinal cord injury: Novel spotlight.

Spinal cord injury (SCI) may lead to persistent locomotor dysfunction and somatosensory disorders, which adversely affect the quality of life of patients and cause a significant economic burden to the society. The efficacies of current therapeutic interventions are still far from satisfaction as the secondary damages resulting from the complex and progressive molecular alterations after SCI are not properly addressed. Recent studies revealed that long non-coding RNAs (lncRNAs) are abundant in the brain and might play critical roles in several nervous system disorders. At the cellular level, lncRNAs have been shown to regulate the expression of protein-coding RNAs and hence participate in neuronal death, demyelination and glia activation. Notably, SCI is characterized by these biological processes, suggesting that lncRNAs could be novel modulators in the pathogenesis of SCI. This review describes recent progresses in the lncRNA transcriptome analyses and their molecular functions in regulating SCI progression.

A randomized controlled trial on effects of different hemostatic sponges in posterior spinal fusion surgeries.

BACKGROUND: Spinal fusion surgery is associated with significant blood loss, which may result in potential clinical complications, it is necessary to take safe and effective measures to reduce blood loss in surgery. We perform this study to assess the impact of three different hemostatic materials on perioperative blood loss. METHODS: We performed a Randomized Controlled Trial research and recruited patients with lumbar disease into the study between November 2013 and March 2015. All the participants were randomly assigned to 3 groups using a simple equal probability randomization scheme: Group A (Stypro hemostatic sponge), Group B (Collagen hemostatic sponge) and Group C (gelatin sponge). We compared postoperative blood loss between these 3 groups. RESULTS: In our study, drainage volume in the first 24 h of patients in Group A and B is significantly smaller, as well as total postoperative volumes of drainage (p < 0.05) during their hospital stay. The drainage volumes in the second 24 h were similar in the 3 groups. We also found that the average drainage Hematocrit (HCT) reduced over time, the average HCT of drainage is 18.04% and 11.72% on the first day and on the second day respectively. CONCLUSIONS: Hemostatic collagen sponge demonstrated better hemostasis effects than gelatin sponge with lower volume of postoperative drainage volume and blood loss in posterior spinal fusion surgery. TRIAL REGISTRATION: The trial registration number (TRN) of the study is ISRCTN29254316 and date of registration is 25/10/2016. Our trial was registered retrospectively.

Effects of application of corn straw on soil microbial community structure during the maize growing season.

This study investigated the influence of corn straw application on soil microbial communities and the relationship between such communities and soil properties in black soil. The crop used in this study was maize (Zea mays L.). The five treatments consisted of applying a gradient (50, 100, 150, and 200%) of shattered corn straw residue to the soil. Soil samples were taken from May through September during the 2012 maize growing season. The microbial community structure was determined using phospholipid fatty acid (PLFA) analysis. Our results revealed that the application of corn straw influenced the soil properties and increased the soil organic carbon and total nitrogen. Applying corn straw to fields also influenced the variation in soil microbial biomass and community composition, which is consistent with the variations found in soil total nitrogen (TN) and soil respiration (SR). However, the soil carbon-to-nitrogen ratio had no effect on soil microbial communities. The abundance of PLFAs, TN, and SR was higher in C1.5 than those in other treatments, suggesting that the soil properties and soil microbial community composition were affected positively by the application of corn straw to black soil. A Principal Component Analysis indicated that soil microbial communities were different in the straw decomposition processes. Moreover, the soil microbial communities from C1.5 were significantly different from those of CK (p < 0.05). We also found a high ratio of fungal-to-bacterial PLFAs in black soil and significant variations in the ratio of monounsaturated-to-branched fatty acids with different straw treatments that correlated with SR (p < 0.05). These results indicated that the application of corn straw positively influences soil properties and soil microbial communities and that these properties affect these communities. The individual PLFA signatures were sensitive indicators that reflected the changes in the soil environment condition.

Metagenomic next-generation sequencing for the identification of infections caused by Gram-negative pathogens and the prediction of antimicrobial resistance.

OBJECTIVE: The aim of this study was to evaluate the efficacy of metagenomic next-generation sequencing (mNGS) for the identification of Gram-negative bacteria (GNB) infections and the prediction of antimicrobial resistance. METHODS: A retrospective analysis was conducted on 182 patients with diagnosis of GNB infections who underwent mNGS and conventional microbiological tests (CMTs). RESULTS: The detection rate of mNGS was 96.15%, higher than CMTs (45.05%) with a significant difference (χ 2 = 114.46, P < .01). The pathogen spectrum identified by mNGS was significantly wider than CMTs. Interestingly, the detection rate of mNGS was substantially higher than that of CMTs (70.33% vs 23.08%, P < .01) in patients with but not without antibiotic exposure. There was a significant positive correlation between mapped reads and pro-inflammatory cytokines (interleukin-6 and interleukin-8). However, mNGS failed to predict antimicrobial resistance in 5 of 12 patients compared to phenotype antimicrobial susceptibility testing results. CONCLUSIONS: Metagenomic next-generation sequencing has a higher detection rate, a wider pathogen spectrum, and is less affected by prior antibiotic exposure than CMTs in identifying Gram-negative pathogens. The mapped reads may reflect a pro-inflammatory state in GNB-infected patients. Inferring actual resistance phenotypes from metagenomic data remains a great challenge.