Potential effects of aerosol generation and transmission during bedside endoscope cleaning.

Airborne transmission is among the most frequent types of nosocomial infection. Recent years have witnessed frequent outbreaks of airborne diseases, such as severe acute respiratory syndrome (SARS) in 2002, Middle East respiratory syndrome (MERS) in 2012, and coronavirus disease 2019 (COVID-19), with the latter being on the rampage since the end of 2019 and bringing the effect of aerosols on health back to the fore (Gralton et al., 2011; Wang et al., 2021). An increasing number of studies have shown that certain highly transmissible pathogens can maintain long-term stability and efficiently spread through aerosols (Leung, 2021; Lv et al., 2021). As reported previously, influenza viruses that can spread efficiently through aerosols remain stable for a longer period compared to those that cannot. The World Health Organization (WHO) has stated that aerosol-generating procedures (AGPs) play an important role in aerosol transmission in hospitals (Calderwood et al., 2021). AGPs, referring to medical procedures that produce aerosols, including dental procedures, endotracheal intubation, sputum aspiration, and laparoscopic surgeries, have been reported to be significantly associated with an increased risk of nosocomial infection among medical personnel (Hamilton, 2021).

Gut Microbiome Analysis and Screening of Lactic Acid Bacteria with Probiotic Potential in Anhui Swine.

With the widespread promotion of the green feeding concept of "substitution and resistance", there is a pressing need for alternative products in feed and breeding industries. Employing lactic acid bacteria represents one of the most promising antimicrobial strategies to combat infections caused by pathogenic bacteria. As such, we analyzed the intestinal tract of Anhui local pig breeds, including LiuBai Pig, YueHei Pig, and HuoShou Pig, to determine the composition and diversity of intestinal microbiota using 16S rRNA. Further, the functionality of the pigs' intestinal microbiota was studied through metagenomic sequencing. This study revealed that lactic acid bacteria were the primary contributors to the functional composition, as determined through a species functional contribution analysis. More specifically, the functional contribution of lactic acid bacteria in the HuoShou Pig group was higher than that of the LiuBai Pig and YueHei Pig. Subsequently, the intestinal contents of the HuoShou Pig group were selected for the screening of the dominant lactic acid bacteria strains. Out of eight strains of lactic acid bacteria, the acid-production capacity, growth curve, and tolerance to a simulated intestinal environment were assessed. Additional assessments included surface hydrophobicity, the self-aggregation capability, co-agglutination of lactic acid bacteria with pathogenic bacteria, and an in vitro bacteriostatic activity assay. Lactobacillus johnsonii L5 and Lactobacillus reuteri L8 were identified as having a strong overall performance. These findings serve as a theoretical basis for the further development of pig-derived probiotics, thereby promoting the application of lactic acid bacteria to livestock production.

Effects of probiotics on cecal microbiome profile altered by duck Escherichia coli 17 infection in Cherry Valley ducks.

Avian colibacillosis is one of the most serious infectious bacterial diseases that endanger the modern poultry industry. Lactobacillus is believed to inhibit intestinal pathogens and maintain a healthy gut microbiota. This study aimed to investigate Lactobacillus supplementation in Cherry Valley ducks to prevent the intestinal flora dysbiosis caused by Duck Escherichia coli 17. One hundred and twenty healthy one day old Cherry Valley ducks were randomized to three study groups (Group I = the control group; Group II = duck Escherichia coli 17 challenge group and Group III = DE17 challenge group supplemented with lactic acid bacteria composite preparation). Cherry Valley ducks in Group II and Group III were gavage challenged with DE17 (1 × 105 CFU/mL) on day 14. Pyrosequencing of the V3/V4 variable regions of the genes encoding for 16S rRNA was used for sequence analysis. The results showed that the normal intestinal microecology was affected by DE17, including a relative increase in proteobacteria. At the same time, the Lactobacillales were increased and harmful bacteria were decreased in different intestinal segments of ducks in Group III, compared to those in Group II. Network analysis showed that dietary lactic acid bacteria addition improved the interaction pattern within the cecal microbiota of ducks and the result showed that in Ruminococcus_2 was independently present in the group III and Lachnospiraceae_NK4A136_group species correlation existed between group I and group III. This study proved that oral supplementation with Lactobacillus casei 1.2435, Lactobacillus rhamnosus 621 and Lactobacillus rhamnosus A4 can mitigate DE17 induced intestinal flora dysbiosis.

Antagonistic trait of Lactobacillus reuteri S5 against Salmonella enteritidis and assessment of its potential probiotic characteristics.

Salmonella enteritidis is an important foodborne pathogen that has caused multiple outbreaks of infection associated with poultry and egg consumption. Thus, the prevention and inhibition of Salmonella enteritidis infection are of great concern. Lactic acid bacteria have anti-pathogenic activity; however, their underlying mechanisms and modes of action have not yet been clarified. In this study, the antibacterial mechanism of Lactobacillus reuteri S5 (L. reuteri S5) against Salmonella enteritidis ATCC13076 (S. enteritidis ATCC13076) was studied by different methods. We found that L. reuteri S5 was able to form a stable biofilm formation, colonizing the entire intestinal tract of chickens. In addition, bacterial cultures and the cell-free supernatant (CFS) of L. reuteri S5 inhibited SE ATCC13076 growth, and this growth inhibition was also observed in the co-culture assay. This effect may be predominantly caused by antimicrobial metabolites produced by L. reuteri S5. Furthermore, treatment with the CFS of L. reuteri S5 resulted in a significant reduction in the expression of Salmonella virulence, motility and adhesion genes and a significant reduction in the motility ability and inhibitory effect on biofilm formation. In addition, the damage to the membrane structure and intracellular structure induced by the CFS of L. reuteri S5 could be observed on Transmission electron microscopy images and dodecyl sulfate, sodium salt (SDS)-Polyacrylamide gel electrophoresis confirmed the disruptive action of the CFS of L. reuteri S5 on the cytoplasmic membrane. Our findings demonstrate that L. reuteri S5, an intestinal Lactobacillus species associated with chicken health, is able to form biofilm and stably colonize chicken intestines. It also possesses anti-SE activity, preventing SE growth, inhibits the expression of SE genes involved in adhesion and invasion, virulence and cell membrane integrity, inhibits SE biofilm formation and motility, damages or destroys bacterial structures, and inhibits intracellular protein synthesis. L. reuteri S5 therefore has potential applications as a probiotic agent.

Analyzing the hepatoprotective effect of the Swertia cincta Burkillextract against ANIT-induced cholestasis in rats by modulating the expression of transporters and metabolic enzymes.

ETHNOPHARMACOLOGICAL RELEVANCE: Swertia cincta Burkill was traditionally used for treating jaundice and various types of chronic and acute hepatitis in Yunnan and Tibet in China for hundreds of years. This study aims to investigate the protective effect of S. cincta Burkill (ESC) extract on alpha-naphthylisothiocyanate (ANIT)-induced hepatotoxicity and cholestasis in rats. MATERIALS AND METHODS: Crude extracts were prepared using 90% ethanol and by vacuum drying. We utilized an ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/Q-TOF-MS) system to conduct a phytochemical analysis of the active components of ESC. Liver function was evaluated by measuring the serum levels of enzymes and components and by analyzing the liver histology. We also measured the expression of bile metabolism-related transporters and metabolic enzymes at both protein and mRNA levels to elucidate the underlying mechanisms. RESULTS: ESC analysis using an UHPLC/Q-TOF-MS revealed eight compounds. Oral administration of ESC to ANIT-treated rats can significantly reduce the increases in serum levels of ALT, AST, ALP, TBIL, and TBA. It can also improve liver pathology and bile flow. Western blot and qRT-PCR analyses showed that ESC upregulated the protein and mRNA expression of Fxr, Ntcp, Bsep, Cyp7a1, Mrp2, and Mdr2. CONCLUSION: ESC could alleviate liver injury by reducing enzyme activities of serums, improving liver pathology and bile flow. The protective mechanism was associated with regulation of the expression of hepatic transporters and metabolic enzymes.

Metabolism profiles of icariin in rats using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry and in vitro enzymatic study.

Icariin (ICA), the major constituent of Epimedium brevicornu Maxim, is recognized as an effective agent for the treatment of osteoporosis. In our previous report, the relatively short half-life (74min) and poor bioavailability (approximately 0.1%) of ICA in rats suggested that not only ICA itself but also its metabolites could be responsible for the observed osteoporosis treatment effect. Therefore, the present study aimed at identifying the metabolites of ICA in rat plasma, bile, urine, and feces after the administration of a single oral dose of ICA (150mg/kg). In this work, ultra-high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/Q-TOF-MS) method was established to identify the metabolic profiles following intragastric administration of pure ICA in rats. The blood, bile, urine, and feces samples of the rats were investigated to explore the complete metabolic pathway of ICA in vivo. A total of 14 metabolites were detected in the bile, revealing that the bile is the main excretion pathway for ICA and its metabolites. The conjugated metabolites as observed in vivo, was further confirmed by the in vitro enzymatic study. Five metabolites of ICA, including demethylicariin, icariside I-3-O-glucuronide, demethylicariside II, demethylicariside II-7-O-glucuronide, and dehydroxyicaritin-glucuronide, were reported for the first time in the literature. In addition, the results revealed that the principal metabolism pathways of ICA in rat were deglycosylation and glucuronidation after deglycosylation.

Characterization of picroside II metabolites in rats by ultra-high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Picroside II, a bioactive compound isolated from Picrorhiza scrophulariiflora Pennell, has been reported to have hepatoprotective, neuroprotective, and antioxidant effects. However, the detailed in vivo biotransformation of this compound has been rarely reported. This study aimed to investigate the metabolic profiles of picroside II in rats by using ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry. Metabolite structures were elucidated based on accurate mass measurements of deprotonated molecules and their fragmentation patterns. Thirteen metabolites were structurally identified, and the detailed metabolic pathways were proposed. The findings revealed that after oral administration, picroside II mainly undergoes four metabolic pathways. In the first pathway, picroside II is deglycosylated to generate aglycone, which is isomerized to a dialdehyde-type intermediate. A series of metabolic reactions, including glucuronidation, subsequently occurs. In the second pathway, picroside II is subjected to ester bond hydrolysis to form vanillic acid, which is further subjected to sulfate conjugation, glycine conjugation, glucuronidation, and demethylation. In the third pathway, picroside II is directly conjugated with glucuronic acid to yield a predominant metabolite (M01) in plasma. In the fourth pathway, picroside II is directly conjugated with sulfate. These findings provide insights into the in vivo disposition of picroside II and are useful to understand the mechanism of effectiveness and toxicity of this compound as well as P. scrophulariiflora-related preparations.

Key Role of ROS in the Process of 15-Lipoxygenase/15-Hydroxyeicosatetraenoiccid-Induced Pulmonary Vascular Remodeling in Hypoxia Pulmonary Hypertension.

We previously reported that 15-lipoxygenase (15-LO) and its metabolite 15-hydroxyeicosatetraenoic acid (15-HETE) were up-regulated in pulmonary arterial cells from both pulmonary artery hypertension patients and hypoxic rats and that these factors mediated the progression of pulmonary hypertension (PH) by affecting the proliferation and apoptosis of pulmonary arterial (PA) cells. However, the underlying mechanisms of the remodeling induced by 15-HETE have remained unclear. As reactive oxygen species (ROS) and 15-LO are both induced by hypoxia, it is possible that ROS are involved in the events of hypoxia-induced 15-LO expression that lead to PH. We employed immunohistochemistry, tube formation assays, bromodeoxyuridine (BrdU) incorporation assays, and cell cycle analyses to explore the role of ROS in the process of 15-HETE-mediated hypoxic pulmonary hypertension (HPH). We found that exogenous 15-HETE facilitated the generation of ROS and that this effect was mainly localized to mitochondria. In particular, the mitochondrial electron transport chain and nicotinamide-adenine dinucleotide phosphate oxidase 4 (Nox4) were responsible for the significant 15-HETE-stimulated increase in ROS production. Moreover, ROS induced by 15-HETE stimulated endothelial cell (EC) migration and promoted pulmonary artery smooth muscle cell (PASMC) proliferation under hypoxia via the p38 MAPK pathway. These results indicated that 15-HETE-regulated ROS mediated hypoxia-induced pulmonary vascular remodeling (PVR) via the p38 MAPK pathway.

Improvement of hydrophobic integral membrane protein identification by mild performic acid oxidation-assisted digestion.

Integral membrane proteins (IMPs) are critical for the maintenance of biological systems and represent important targets for the treatment of disease. The hydrophobicity and low abundance of IMPs make them difficult to analyze. In proteomic analyses, hydrophobic peptides including transmembrane domains are often underrepresented, and this reduces the sequence coverage and reliability of the identified IMPs. Here we report a new strategy, mild performic acid oxidation treatment (mPAOT), for improvement of IMP identification. In the mPAOT strategy, the hydrophobicity of IMPs is significantly decreased by oxidizing their methionine and cysteine residues with performic acid, thereby improving the solubility and enzymolysis of these proteins. The application of the mPAOT strategy to the analysis of IMPs from human nasopharyngeal carcinoma CNE1 cell line demonstrated that many IMPs, including those with high hydrophobicity, could be reliably identified.

Dataset of the plasma membrane proteome of nasopharyngeal carcinoma cell line HNE1 for uncovering protein function.

Nasopharyngeal carcinoma (NPC) is a commonly occurring tumor in southern China and Southeast Asia. The current study focused on developing an extensive analysis method for the peripheral and integral proteins of NPC cell line HNE1. The peripheral membrane proteins were extracted by biotinylated enrichment, 0.1 M Na2CO3, and H2O. Integral or total plasma membrane fractions were prepared using 30% Percoll density grade centrifugation with or without 0.1 M Na2CO3 treatment and evaluated by Western blot analysis. The proteins were subjected to two-dimensional electrophoresis combined with tandem mass spectrometry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis combined with tandem mass spectrometry, and shotgun analysis. We identified 371, 180, and 702 proteins from peripheral, integral, and total plasma membrane fractions, respectively. In all, 848 non-redundant proteins (534 groups) were identified. Binding, catalytic, and structural molecules were the major classes. In addition to the known cell surface markers of NPC cells, the analysis revealed 311 proteins involved in multiple cell-signaling pathways and 25 proteins in disease pathways that are characteristic of cancer cells. By searching the Differentially Expressed Protein Database (http://protchem.hunnu.edu.cn/depd/index.jsp), 199 proteins were found to be differentially expressed in previous cancer proteome research. A 671 protein-protein interaction network was obtained, including 178 identified proteins in this work. The plasma membrane localization of five proteins was confirmed by immunological techniques, validating this proteomic strategy. Our study could offer some help for understanding the molecular mechanism of NPC.