Characterization and dynamics of intestinal microbiota in patients with Clostridioides difficile colonization and infection.

Gut microbiota dysbiosis increases the susceptibility to Clostridioides difficile infection (CDI). In this study, we monitored C. difficile colonization (CDC) patients from no CDC status (CDN) to CDC status (CDCp) and CDI patients from asymptomatic status before CDI (PRECDI), CDI status (ONCDI), to asymptomatic status after CDI (POSTCDI). Based on metagenomic sequencing, we aimed to investigate the interaction pattern between gut microbiota and C. difficile. There was no significant difference of microbiota diversity between CDN and CDCp. In CDCp, Bacteroidetes and short-chain fatty acid (SCFA)-producing bacteria increased, with a positive correlation between SCFA-producing bacteria and C. difficile colonization. Compared with PRECDI, ONCDI and POSTCDI showed a significant decrease in microbiota diversity, particularly in Bacteroidetes and SCFA-producing bacteria, with a positive correlation between opportunistic pathogen and C. difficile. Fatty acid metabolism, and amino acid biosynthesis were enriched in CDN, CDCp, and PRECDI, while bile secretion was enriched in ONCDI and POSTCDI. Microbiota and metabolic pathways interaction networks in CDN and CDCp were more complex, particularly pathways in fatty acid and bile acid metabolism. Increasing of Bacteroidetes and SCFA-producing bacteria, affecting amino acid and fatty acid metabolism, is associated with colonization resistance to C. difficile and inhibiting the development of CDI.

Aerobic Treadmill Exercise Upregulates Epidermal Growth Factor Levels and Improves Learning and Memory in d-galactose-Induced Aging in a Mouse Model.

Previous studies have demonstrated that exercise improves cognitive function in Alzheimer's disease mice but the exact mechanism needs further studies. This research aimed to study the effects of aerobic treadmill exercise on epidermal growth factor (EGF) levels and learning and memory in d-galactose-induced aging in a mouse model. Forty male Kunming mice were analyzed in this study and randomly divided into 4 groups: control (C group), aerobic exercise (AE group), d-galactose (D-gal group), and d-galactose + aerobic exercise (D-gal + AE group). The C and AE groups received a daily mid-scapular subcutaneous injection of .9% saline for 40 days. Mice in the D-gal and D-gal + AE groups were subcutaneously injected with d-galactose (1.25 mg/kg) once daily for 40 days. The mice in the AE group and D-gal + AE group completed 40 days of aerobic treadmill exercise. Learning and memory were evaluated by step-down tests. Specifically, 24 h after the behavioral test, blood was collected and brain tissue was extracted, and superoxide dismutase (SOD) and acetylcholinesterase activities were detected. The neurons in the CA1 and CA3 regions of the hippocampus were counted by Nissl staining. The number of EGF-positive cells was observed by immunohistochemical methods. In the learning test, the reaction time in the D-gal group increased significantly (P < .05), while the error numbers in the D-gal group tended to decrease compared with AE, D-gal + AE, and C groups. In the memory test, the latency of mice in the D-gal group was lower, while the error in this group was higher than in the other groups (P < .05). The activities of SOD and acetylcholinesterase were lower in the D-gal group than in the other groups (P < .05). The number of EGF-positive cells and neurons in the hippocampal CA1 and CA3 regions in the D-gal + AE group was higher compared to those in the D-gal group (P < .05), and lower in groups with mice that were not injected with d-galactose. Aerobic treadmill exercise inhibited SOD activity, increased EGF-positive cells, and decreased neuronal death and apoptosis, thereby improving learning and memory in the mouse model of d-galactose-induced aging.

Prevalent Dominant Acinetobacter baumannii ST191/195/208 Strains in Bloodstream Infections Have High Drug Resistance and Mortality.

Background: Different sequence types of Acinetobacter baumannii (AB) have their own epidemiological characteristics, drug resistance, and toxicity. Methods: AB bloodstream infection (BSI) in the First Affiliated Hospital of Medical College of Zhejiang University from January 2012 to December 2017 were classified by multilocus sequence typing. Clinical data of patients were retrospectively analyzed, drug resistance and toxicity were respectively studied by drug sensitivity and complement killing tests. Results: 247 unduplicated AB strains were collected, and ST191/195/208, the main epidemic dominant strain, accounted for 70.9%. Patients with ST191/195/208 on infection had higher white blood cell (10.8 vs 8.9, p = 0.004), neutrophil% (89.5 vs 86.9, p = 0.005), neutrophil count (9.5 vs 7.1, p = 0.021), D-dimer (6.7 vs 3.8, p = 0.000), total bilirubin (27.0 vs 21.5, p = 0.038), pronatriuretic peptide (324 vs 164, p = 0.042), C-reactive protein (82.5 vs 56.3, p = 0.048), clinical pulmonary infection score (CPIS; 7.33 ± 2.30 vs 6.50 ± 2.72, p = 0.045), and acute physiology and chronic health evaluation-II (APACHE-II; 19.620 ± 5.1850 vs 17.648 ± 6.1251, p = 0.011). Patients with ST191/195/208 had more complications, including pulmonary infection (p = 0.041), septic shock (p = 0.009), and multiple organ failure (p = 0.019). Patients with ST191/195/208 had higher 3 day mortality (24.6% vs 13.9%, p = 0.043), 14 day mortality (46.8% vs 26.8%, p = 0.003), and 28 day mortality (55.0% vs 32.4%, p = 0.001). ST191/195/208 strains had higher drug resistance to most antibiotics, and higher survival rate at 90% normal serum concentration (p < 0.001). Conclusion: ST191/195/208 strains predominate in the hospital and prevails in patients with severe infections with increased multidrug antimicrobial resistance and excessive mortality compared to any other AB stains.

Identification of natural compound garcinone E as a novel autophagic flux inhibitor with anticancer effect in nasopharyngeal carcinoma cells.

CONTEXT: Current chemotherapeutic drugs cannot meet the treatment needs of patients with nasopharyngeal carcinoma (NPC), so urgent action is needed to discover novel chemotherapeutic agents. Our previous study revealed that garcinone E (GE) inhibited the proliferation and metastasis of NPC, suggesting that the compound might display promising anticancer activity. OBJECTIVE: To examine the mechanism underlying the anti-NPC activity of GE for the first time. MATERIALS AND METHODS: For MTS assay, NPC cells were treated with 2.5-20 µmol/L GE or dimethyl sulfoxide for 24, 48, and 72 h. Colony formation capacity, cell cycle distribution, and in vivo xenograft experiment of GE were assessed. MDC staining, StubRFP-sensGFP-LC3 observation, LysoBrite Blue staining, and immunofluorescence examined the autophagy of NPC cells after GE exposure. Western blotting, RNA-sequencing, and RT-qPCR measured protein and mRNA levels. RESULTS: GE suppressed cell viability with an IC50 of 7.64, 8.83 and 4.65 µmol/L for HK1, HONE1 and S18 cells. GE inhibited colony formation and cell cycle, increased autophagosome number, and inhibited the autophagic flux partially by blocking lysosome-autophagosome fusion, and repressed S18 xenograft growth. GE dysregulated the expression of autophagy- and cell cycle-related proteins such as Beclin-1, SQSTM1/p62, LC3, CDKs, and Cyclins. Bioinformatics GO and KEGG pathway enrichment analysis of RNA-seq showed that autophagy was enriched in differentially expressed genes upon GE treatment. DISCUSSION AND CONCLUSION: GE acts as an autophagic flux inhibitor, which may have potential chemotherapeutic use for NPC treatment and may have an application in basic research to explore the mechanisms of autophagy.

Phenotypic and genomic comparison of dominant and nondominant sequence-type of Acinetobacter baumannii isolated in China.

A. baumannii is a common clinical pathogen that often causes pneumonia and bloodstream infections in ICU patients. Sequence types (ST) are used to investigate the distribution and spread of A. baumannii. Biological characteristics such as virulence and resistance may play a role in A. baumannii becoming a specific dominant ST(DST,ST191, ST195 and ST208) strain. To characterize the biological, genetic, and transcriptomic differences between the DST and non-dominant ST(NST,ST462 and ST547,etc.) strains in A. baumannii, we performed several biological experiments and genetic, and transcriptomic analyses. The DST group displayed more resistance ability to desiccation, oxidation, multiple antibiotics, and complement killing than the NST group. However, the latter had higher biofilm formation ability than the former. The genomic analysis showed the DST group exhibited more capsule-related and aminoglycoside-resistant genes. Besides, GO analysis indicated that functions involved in lipid biosynthetic, transport, and the metabolic process were up-regulated in the DST group, while KEGG analysis manifested that the two-component system related to potassium ion transport and pili were down-regulated. In short, resistance to desiccation, oxidation, multiple antibiotics, and serum complement killing are important reasons for the formation of DST. Genes related to capsule synthesis and lipid biosynthesis and metabolism play an important role at the molecular level in the formation of DST.

[The Expression and Correlation of miR-195, miR-125 and Calreticulin in Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To analyze the expression and correlation of microRNA-195 (miR-195), miR-125 and calreticulin in diffuse large B-cell lymphoma (DLBCL). METHODS: From April 2020 to April 2021, 80 DLBCL patients with complete data archived by the Pathology Department of Handan First Hospital and The Second Hospital of Hebei Medical University were selected as the study group, and 70 patients with reactive lymph node hyperplasia were selected as the control group. The expressions of miR-195 and miR-125 were detected by real-time fluorescence quantitative PCR, and the expression of calreticulin was detected by Western blot. Pearson correlation was used to analyze the correlation between miR-195, miR-125, calreticulin and DLBCL, and ROC curve was used to analyze the predictive value of miR-195, miR-125 and calreticulin for DLBCL. RESULTS: Compared with the control group, the expression of miR-195 decreased but miR-125 and calreticulin increased in the study group (P<0.001). The expression levels of miR-195, miR-125 and calreticulin were not related to sex, age, primary site and B symptoms of patients with DLBCL, but related to immunophenotype, Ann Arbor stage, lactate dehydrogenase, IPI score, nodule involvement and Ki-67 index. The expression of miR-195 decreased and the expression of miR-125 and calreticulin increased in DLBCL paitents with non-germinal center source, Ann Arbor stage III-IV, lactate dehydrogenase > 245 U/L, IPI score 3-5, nodule involvement≥2 and Ki-67 index≥75% (P<0.05). Pearson correlation analysis showed that miR-195 and miR-125 were negatively correlated (r=-0.536, P=0.001), miR-195 and calreticulin were negatively correlated (r=-0.545, P=0.001), while miR-125 and calreticulin were positively correlated (r=0.523, P=0.001). ROC curve showed that compared with the single diagnosis of miR-195, miR-125 and calreticulin, the combination of the three items had higher predictive value for DLBCL (P<0.001). CONCLUSION: The expression of miR-195 decreases and the expression of miR-125 and calreticulin increase in patients with DLBCL. Along with the increase of disease stage and IPI score, the decrease of miR-195 and the increase of miR-125 and calreticulin aggravate gradually. The three items may participate in the occurrence and progress of DLBCL.

Effects of serial and acute enteric-coated sodium bicarbonate supplementation on anaerobic performance, physiological profile, and metabolomics in healthy young men.

Background: Previous studies have reported that sodium bicarbonate ingestion may enhance high-intensity exercise performance and cause severe gastrointestinal distress. However, enteric-coated sodium bicarbonate may reduce gastrointestinal symptoms of sodium bicarbonate after oral administration. This remains to be confirmed. This study aimed to verify the effects of serial and acute enteric-coated sodium bicarbonate supplementation on anaerobic performance, physiological profile, and metabolomics in healthy young men. Methods: Healthy young males (n = 12) ingested 0.2 g/kg body mass of enteric-coated sodium bicarbonate (ES) in serial enteric-coated sodium bicarbonate (SES, continuous ES supplementation for 5 days) and acute enteric-coated sodium bicarbonate (AES, acute ES supplementation before exercise) or a placebo (PL) in a randomized crossover design. After each supplement protocol, the participants completed four Wingate anaerobic tests (WAT). The first three Wingate tests (testing anaerobic capacity) were performed with a 5-min passive recovery between each. After the third Wingate test, participants were required to complete a 50-min recovery followed by a fourth WAT test (testing the recovery of anaerobic capacity after 50-min intervals). Blood lactate (BLA), heart rate (HR), and ratings of perceived exertion (RPE) were measured in all conditions during the test, as was the subjective gastrointestinal-symptoms assessment questionnaire (GSAQ). Mean power (MP) and peak power (PP) were recorded after four WATs. Urine samples were collected before the test and 50 min after the 3rd WAT. Results: Serial enteric-coated sodium bicarbonate supplementation improved anaerobic capacity in the third bout of WATs, as observed based on an increase in mean power (SES vs. PL (613 ± 57 vs. 542 ± 64 W), P = 0.024) and peak power (SES vs. PL (1,071 ± 149 vs. 905 ± 150 W), P = 0.016). Acute ES supplementation did not affect anaerobic capacity. The occurrence of gastrointestinal symptoms after enteric-coated sodium bicarbonate supplementation was minimal and no difference compared to placebo in the current study. In particular, serial enteric-coated sodium bicarbonate supplementation had no gastrointestinal side effects before the test. The AES and SES groups had a trivial effect on blood lactate compared to the PLA group. There was no significant difference in HR and RPE among the three groups. Based on targeted metabolomics analysis, the 50 min after the third WAT, the levels of lactate (P < 0.001), L-Malic acid (P < 0.05), and oxaloacetate (P < 0.05) were significantly higher in the SES group than in the PL group. Compared with the AES group, the levels of lactate and fumarate in the SES group were significantly increased (P < 0.05). Conclusions: Our study indicates that serial enteric-coated sodium bicarbonate supplementation positively improves anaerobic performance among healthy young men. However, acute ingestion of enteric-coated sodium bicarbonate did not improve anaerobic exercise performance. Either with serial or acute supplementation doses, enteric-coated sodium bicarbonate produced fewer gastrointestinal symptoms and no difference compared to placebo, especially with no gastrointestinal side effects after serial supplementation. Serial and acute supplementation of enteric-coated sodium bicarbonate might tend to promote lactate clearance. Furthermore, serial enteric-coated sodium bicarbonate ingestion may cause changes in the metabolism of lactate, L-Malic acid, oxaloacetate, and fumarate 50 min after exercise, which presumably may promote the tricarboxylic acid cycle and lactate clearance.

Exercise on Striatal Dopamine Level and Anxiety-Like Behavior in Male Rats after 2-VO Cerebral Ischemia.

The purpose of this study was to discuss the effect of voluntary wheel running on striatal dopamine levels and anxiety-like behavior in rats with global cerebral ischemia. The male Sprague-Dawley rats were signed on in this study and randomly divided into following 4 groups: Control group (C group), Sham group (S group), ischemia group (I group), and 3 weeks physical exercise before ischemia group (3RI group). The rats in the 3RI group were placed in a voluntary running wheel for three weeks to exercise. Then, the rats in I and 3RI groups received bilateral carotid artery ligation (2-VO) operation. The C and S group did not perform voluntary running exercise and the bilateral common carotid arteries of S group were exposed without ligation. In vivo microdialysis was used in conjunction with high performance liquid chromatography (HPLC) and electrochemical detection to ascertain the level of dopamine in the striatum. Elevated plus maze (EPM) and open field (OF) were used to test anxiety status at 24 hours and 7days after 2-VO cerebral ischemia. Meanwhile, gait and motor coordination evaluations were carried out to eliminate the influence of non-specific motor problems. The results indicated that cerebral ischemia instigate the increase of striatal dopamine in I group rats during acute cerebral ischemia. A 3-week voluntary wheel running significantly enhances the striatal dopamine before ischemia and obstructs a further increase of dopamine during acute cerebral ischemia in 3RI group rats. At 24 hours after ischemia, striatal dopamine returned to pre-ischemic levels in 3RI group. Striatal dopamine in I group were less than pre-ischemic levels at 7 days. Behavioral data indicated that 3-week voluntary wheel running promoted recovery of anxiety-like behavior and gait were not affected by 2-VO cerebral ischemia at 24 hours post-ischemia rats. Therefore, it can be concluded that 3-week physical exercise significantly increased the striatal dopamine and improved anxiety-like behavior by inhibiting the increase of dopamine during acute cerebral ischemia and suppressing the decrease of dopamine after 24 hours and 7 days cerebral ischemia.

Corrigendum: Comparative respiratory tract microbiome between carbapenem-resistant Acinetobacter baumannii colonization and ventilator associated pneumonia.

[This corrects the article DOI: 10.3389/fmicb.2022.782210.].

Investigation of the Effectiveness of Traditional Breathing Therapy on Pulmonary Function in College Students with Obstructive Sleep Apnea.

Background: Obstructive sleep apnea (OSA) is a problem that involves many body systems, but its impact on the respiratory system deserves special attention. While there are many studies investigating the use of continuous positive airway pressure (CPAP) to treat lung function in patients with sleep apnea, the lack of studies in the literature on the effects of traditional breathing therapy on lung function in patients with OSA prompted us to conduct such a study. Objective: The present randomized trial aims to assess the effect of traditional breathing therapy on daytime sleepiness and pulmonary function in college students with OSA. Methods: Forty college students (male) with OSA were randomly divided into two groups: the control group (CG) and the traditional breathing therapy group (TG). Daytime sleepiness symptoms in OSA are measured primarily by the Epworth Sleepiness Scale (ESS). Pulmonary function measurements included FVC, FEV1, PEE, and MEF50%. The changes in morning blood pressure (BP), including diastolic BP and systolic BP, were also recorded. Data were recorded before and after the experiment. Results: A decrease in ESS at 12 weeks after intervention had statistical significance compared with values recorded before intervention (P < 0.05). A decrease in systolic and diastolic BP at 12 weeks after intervention had statistical significance compared with values recorded before intervention (P < 0.05). Comparisons made in terms of pulmonary functions demonstrated a statistically significant increase in 12-week postintervention values of FVC, FEV1, PEF, and MEF50% (P < 0.05). Conclusion: Our study shows the positive effects of traditional breathing therapy on pulmonary function parameters. This suggests that traditional breathing therapy treatment in OSA patients is as effective as CPAP on pulmonary function, while there is an improvement in daytime sleepiness and a modest decline in the mean daytime systolic and diastolic BP.

Comparative Respiratory Tract Microbiome Between Carbapenem-Resistant Acinetobacter baumannii Colonization and Ventilator Associated Pneumonia.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a common cause of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients, but its infection and colonization state are difficult to distinguish. If the judgment is wrong, it may aggravate the abuse of antibiotics and further accelerate the evolution of drug resistance. We sought to provide new clues for the diagnosis, pathogenesis and treatment of CRAB VAP based on lower respiratory tract (LRT) microbiota. Methods: A prospective study was conducted on patients with mechanical ventilation from July 2018 to December 2019 in a tertiary hospital. Multi-genomics studies (16S rRNA amplicon, metagenomics, and whole-genome sequencing [WGS]) of endotracheal deep aspirate (ETA) were performed. Results: Fifty-two ICU patients were enrolled, including 24 with CRAB VAP (CRAB-I), 22 with CRAB colonization (CRAB-C), and six CRAB-negative patients (infection-free) (CRAB-N). Diversity of pulmonary microbiota was significantly lower in CRAB-I than in CRAB-C or CRAB-N (mean Shannon index, 1.79 vs. 2.73 vs. 4.81, P < 0.05). Abundances of 11 key genera differed between the groups. Acinetobacter was most abundant in CRAB-I (76.19%), moderately abundant in CRAB-C (59.14%), and least abundant in CRAB-N (11.25%), but its interactions with other genera increased in turn. Metagenomics and WGS analysis showed that virulence genes were more abundant in CRAB-I than in CRAB-C. Multi-locus sequence typing (MLST) of 46 CRAB isolates revealed that the main types were ST208 (30.43%) and ST938 (15.22%), with no difference between CRAB-I and CRAB-C. Conclusion: Lower respiratory tract microbiota dysbiosis including elevated relative abundance of Acinetobacter and reduced bacterial interactions, and virulence enrichment may lead to CRAB VAP.

Different Exercise Time on 5-HT and Anxiety-like Behavior in the Rat With Vascular Dementia.

BACKGROUND: Previous studies have demonstrated that pre-exercise suppresses anxiety-like behavior, but the effects of different exercise times on vascular dementia induced anxiety-like behavior have not been well investigated. OBJECTIVE: The present study aims to investigate the underlying neurochemical mechanism of different pre-vascular-dementia exercise times on 5-HT and anxiety-like behavior in rats with vascular dementia. METHODS: 32 Sprague-Dawley (SD) rats were randomly divided into 4 groups: sham group (S group, n = 8), vascular dementia group (VD group, n = 8), 1-week physical exercise and vascular dementia group (1WVD group, n = 8), and 4 weeks physical exercise and vascular dementia group (4WVD group, n = 8). 1 week and 4 weeks of voluntary wheel running were used as pre-exercise training. The vascular dementia model was established by bilateral common carotid arteries occlusion (BCCAo) for 1 week. But bilateral common carotid arteries were not ligated in the sham group. The level of hippocampal 5-HT was detected with in vivo microdialysis coupled with high-performance liquid chromatography (MD-HPLC). Elevated plus maze (EPM), open field (OF), and light/dark box test were used to test anxiety-like behavior. RESULTS: Compared with the C group, the hippocampal 5-HT was significantly decreased in the VD group after 1 week of ligated operation. The hippocampal 5-HT levels in 1WVD and 4WVD groups were substantially higher than the level in the VD group. The hippocampal 5-HT level has no significant difference among C, 1WVD, and 4WVD. Behavioral data suggested that the rats in the VD group developed obvious anxiety-like behavior after 1 week of ligation surgery. Still, the rats in 1WVD and 4WVD groups did not show significant anxiety-like behavior. CONCLUSION: Both 1 week and 4 weeks of voluntary running wheel exercise can inhibit the anxiety-like behavior in rats with vascular dementia by upregulating 5-HT levels in the hippocampus in the VD model.

The Physiological Profile Following Two Popular Cold Interventions After Activity in Hot and Humid Environment.

This research aims to describe and compare the effects of partial-body cryotherapy (PBC) and cold-water immersion (CWI) on the physiological responses of soccer players after cycling in a hot and humid environment. Sixteen elite soccer players participated in three experiments, and received CWI (13°C for 15 min), PBC (110°C-140°C for 3 min), and CON (room temperature: 21°C ± 2°C), respectively, after aerobic and anaerobic cycling in a hot and humid environment (temperature: 35°C-38°C; humidity: 60%-70%). Heart rate (HR), blood lactate (BLa-), perfusion index (PI), oxygen saturation (SaO2), core temperature (Tc), skin temperature (Ts), and rating of perceived exertion (RPE) were assessed at baseline and through 20 min (5-min intervals). HR was lower in CWI than CON after 20 min (p < .05). SaO2 was higher in CWI than PBC and CON between 10 and 20 min (p < .05). Tc was lower from CWI and PBC than CON between 10 and 20 min (p < .05). Ts was lower in PBC than CWI between 15 and 20 min (p < .05). RPE was lower in PBC than CON 20 min after the exercise (p < .05). No main group differences for BLa- and PI were observed. The physiological effects of PBC are generally similar to CWI. Compared with CON, both CWI and PBC could promote the recovery of physiological indexes within 20 min of exercise in a hot and humid environment. However, PBC can lead to a decrease in SaO2 due to excessive nitrogen inhalation.

Effects of Equine-Assistant Activity on Gross Motor Coordination in Children Aged 8 to 10 Years.

Generally, adequate motor coordination (MC) ability is one among the critical factors for the overall development of children. In this paper, we have thoroughly analyzed the effects of equine-assistant activity (EAA) training on MC in children. For this purpose, MC test, specifically for children, was used to the Körperkoordinationstest für Kinder (KTK), and a total of 100 children, particularly those in 8 to 10 age, were equally separated into equine-assistant activity group (EAAG) and control group (CG), respectively. The EAAG group has attended a 14-week EAA training program, while the CG joined in physical education activity once per week. The experimental results have indicated that four indices of KTK test (i.e., backward walk [WB], height jump [HH], jumping sideways [JS] and moving sideways [MS], and motor quotient [MQ] score) showed significant differences ( ∗ P < 0.05) after a 14-week EAA training. Furthermore, the indices of physical fitness test, standing long jump (SLJ), and sit and reach (SAR) showed significant differences ( ∗ P < 0.05), but the handgrip (HG) increased slightly without significant difference (P > 0.05) after a 14-week EAA training. In conclusion, there were improvements in MC, lower limb strength, and flexibility by EAAG for those who participated in a 14-week EAA training, and this study has demonstrated the effectiveness of the KTK assessment of MC in children 8 to 10 years.

Comparative genomic and transmission analysis of Clostridioides difficile between environmental, animal, and clinical sources in China.

Clostridioides difficile is the most common pathogen causing antibiotic-associated diarrhea. Previous studies showed that diverse sources, aside from C. difficile infection (CDI) patients, played a major role in C. difficile hospital transmission. This study aimed to investigate relationships and transmission potential of C. difficile strains from different sources. A prospective study was conducted both in the intensive care unit (ICU) and six livestock farms in China in 2018-2019. Ninety-eight strains from CDI patients (10 isolates), asymptomatic hospitalized carriers (55), the ICU environment (12), animals (14), soil (4), and farmers (3) were collected. Sequence type (ST) 3/ribotype (RT) 001, ST35/RT046, and ST48/RT596 were dominant types, distributed widely in multiple sources. Core-genome single-nucleotide polymorphism (cgSNP) analysis showed that hospital and farm strains shared several common clonal groups (CGs, strains separated by ≤ 2 cgSNPs) (CG4/ST3/RT001, CG7/ST35/RT046, CG11/ST48/RT596). CDI patients, asymptomatic carriers, and the ICU environment strains also shared several common CGs. The number of virulence genes was not statistically different between strains from different sources. Multi-source strains in the same CG carried identical virulence gene sequences, including pathogenicity genes at the pathogenicity locus and adhesion-related genes at S-layer cassette. Resistance genes (ermB, tetM, etc.) were widespread in multiple sources, and multi-source strains in the same CG had similar resistance phenotypes and carried consistent transposons and plasmid types. The study indicated that interspecies and cross-regional transmission of C. difficile occurs between animals, the environment, and humans. Community-associated strains from both farms and asymptomatic hospitalized carriers were important reservoirs of CDI in hospitals.

[Relationship between Polymorphism of miR-155 and Its Target Gene MyD88 and Clinicopathological Features of Diffuse Large B-cell Lymphoma].

OBJECTIVE: To investigate the relationship between the polymorphism of miR-155 and its target gene MyD88 and clinicopathological features of diffuse large B-cell lymphoma (DLBCL). METHODS: 135 cases of DLBCL patients in our hospital from March 2015 to August 2017 were selected, and 90 cases of reactive hyperplasia of lymph nodes were selected as the control group. The relative expression of miR-155 and MyD88 gene polymorphism were detected in the two groups, and the relationship between miR-155 and MyD88 gene polymorphism and clinicopathological characteristics of DLBCL was analyzed. RESULTS: The relative expression of miR-155 in DLBCL patients was significantly higher than that in the control group (P<0.05). The mutation rate of MyD88 L265P in DLBCL group was significantly higher than that in control group (P<0.05). The relative expression of miR-155 in patients with MyD88 L265P mutation was significantly higher than that in patients with wild-type DLBCL (P<0.05). The relative expression of miR-155 and the polymorphism of MyD88 L265P were associated with lesion location, stage, BCL-2 protein expression and MyD88 protein expression in DLBCL patients (t=7.461、8.804、6.487、10.812； χ2=10.681、8.599、7.251、23.008；P<0.05). The survival of DLBCL patients with low miR-155 expression was significantly better than that with high miR-155 expression (P<0.05). The survival of wild-type DLBCL patients with MyD88 L265P locus was significantly better than that of mutant DLBCL patients (P<0.05). There was a significant positive correlation between the relative expression of miR-155 and the expression of MyD88 protein (r=0.428, P=0.000). CONCLUSION: The abnormal expression of miR-155 and the mutation rate of MyD88 gene in DLBCL patients are increased, and the expression of miR-155 and the mutation of MyD88 gene affect the disease progression and prognosis of patients, which may be potential biological indicators for the diagnosis, treatment and prognosis of DLBCL.

TUC338 Promotes Diffuse Large B Cell Lymphoma Growth via Regulating EGFR/PI3K/AKT Signaling Pathway.

TUC338 is emerging as a novel vital long noncoding RNA (lncRNA) in human cancer; however, its role in diffuse large B cell lymphoma (DLBCL) remains unknown. In this study, we found that TUC338 was remarkably upregulated in DLBCL tissues as compared to matched normal tissues. High TUC338 was closely related to advanced Ann Arbor stage, resistance to CHOP-like treatment, and high IPI (International Prognostic Index). Stable knockdown of TUC338 evidently inhibited cell proliferation and chemotherapy resistance to Adriamycin and induced apoptosis. Further, we found that TUC338 was able to directly bind to miR-28-5p and increased EGFR level, resulting in activating carcinogenic PI3K/AKT signaling, thereby facilitating DLBCL uncontrolled growth. Moreover, we also found that depletion of TUC338 led to the inactivation of EGFR/PI3K/AKT pathway in vivo by using the xenograft tumor model. Preclinically, DLBCL patients with high TUC338 had shorter survival time than those with low TUC338, and serum TUC338 level was identified as an excellent indicator for DLBCL diagnosis. In sum, our findings clearly indicate that TUC338 functions as an oncogenic lncRNA in DLBCL through activating EGFR/PI3K/AKT pathway via sponging and inhibiting miR-28-5p, which may be a promising target for DLBCL treatment.

[Effects of Long Non-coding RNA-TUC338 on the Migration and Proliferation of Lymphoma Cells via PI3K/AKT Signaling Pathway].

OBJECTIVE: To investigate the effect of long non-coding RNA-TUC338 on the proliferation and migration of lymphoma cells. METHODS: The expression of TUC338 in different lymphoma cells was detected by fluorescence quantitative PCR, cell proliferation by sulforhodamine B (SRB) assay, migration of lymphoma cells by transwell assay, and protein expression in PI3K/AKT signaling pathway by Western blot. RESULTS: The expression levels of TUC338 in lymphoma cells Daudi, U937, BC-3, and Raji significantly increased in comparison with human normal T lymphocytes H9 (t=13.277, 10.103, 16.200, and 26.687, P=0.002, 0.005, 0.001, and 0.000). Compared with NC-siRNA group, the number of cells crossing the chamber of TUC338-siRNA group was significantly reduced (t=30.508, P=0.000), the protein expression levels of p-PI3K and p-AKT significantly decreased (t=16.872 and 18.371, P=0.000 and 0.000), and OD530 absorbance values at 24 h, 48 h, and 72 h were significantly lower (P<0.05). CONCLUSION: The expression of TUC338 significantly increases in lymphoma cells, and silence of TUC338 effectively inhibits the activation of PI3K/AKT signaling pathway, thereby inhibiting the proliferation and migration of lymphoma cells, which has a potential application value in diagnosis and treatment of lymphoma.

Comparative Analysis of Virulence and Toxin Expression of Vancomycin-Intermediate and Vancomycin-Sensitive Staphylococcus aureus Strains.

Previous studies on vancomycin-intermediate Staphylococcus aureus (VISA) have mainly focused on drug resistance, the evolution of differences in virulence between VISA and vancomycin-sensitive S. aureus (VSSA) requires further investigation. To address this issue, in this study, we compared the virulence and toxin profiles of pair groups of VISA and VSSA strains, including a series of vancomycin-resistant induced S. aureus strains-SA0534, SA0534-V8, and SA0534-V16. We established a mouse skin infection model to evaluate the invasive capacity of VISA strains, and found that although mice infected with VISA had smaller-sized abscesses than those infected with VSSA, the abscesses persisted for a longer period (up to 9 days). Infection with VISA strains was associated with a lower mortality rate in Galleria mellonella larvae compared to infection with VSSA strains (≥ 40% vs. ≤ 3% survival at 28 h). Additionally, VISA were more effective in colonizing the nasal passage of mice than VSSA, and in vitro experiments showed that while VISA strains were less virulent they showed enhanced intracellular survival compared to VSSA strains. RNA sequencing of VISA strains revealed significant differences in the expression levels of the agr, hla, cap, spa, clfB, and sbi genes and suggested that platelet activation is only weakly induced by VISA. Collectively, our findings indicate that VISA is less virulent than VSSA but has a greater capacity to colonize human hosts and evade destruction by the host innate immune system, resulting in persistent and chronic S. aureus infection.

Characterization of highly virulent community-associated methicillin-resistant Staphylococcus aureus ST9-SCCmec XII causing bloodstream infection in China.

Previous studies have shown that livestock (LA)-MRSA ST398 evolved from a human-adapted methicillin-susceptible S. aureus (MSSA) clone. However, detailed information regarding ST9 is still unclear. Here, we characterized a community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) ST9-SCCmec XII isolate that has not been previously reported to cause serious disease in China. We obtained whole-genome sequences of one ST9-t899-XII isolate-ZY462471-from a patient with bloodstream infection without livestock contact. The antibiotic susceptibilities of ZY462471 were determined and the clinical information was extracted from medical notes and compared with twenty-seven previously sequenced genomes. Phylogenetic reconstruction was performed to investigate the probable host evolutionary origins of ZY462471, and the difference in resistome and virulence factors were investigated. Virulence assay was performed to evaluate the high virulence potential of ZY462471 and compare the virulence between the closest ST9 MSSA neighbours. Clinical data suggested that ZY462471 is a CA-MRSA. Phylogenetic analysis showed a much closer relationship of ZY462471 with human-associated MSSA ST9 isolates than other LA-MRSA ST9 isolates, suggesting that ZY462471 probably evolved from ST9 MSSA predecessors by acquiring an SCCmec cassette. Importantly, virulence assays indicated that ZY462471 was highly virulent and compared with the MSSA ST9 predecessors, ZY462471 did not show attenuated virulence. Finally, we found that ZY462471 harboured an immune evasion cluster (IEC)-carrying ßC-Φ, which is typically found in human clinical S. aureus rather than LA-MRSA isolates, suggesting that ZY4762471 obtained the IEC-carrying ßC-Φs from human clinical S. aureus strains. Considering its high virulence potential, this strain should be monitored to prevent more widespread dissemination.