Carbonaceous particulate matter promotes the horizontal transfer of antibiotic resistance genes.

There is growing concern about the transfer of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in airborne particulate matter. In this study, we investigated the effects of various types of carbonaceous particulate matter (CPM) on the transfer of ARGs in vitro. The results showed that CPM promoted the transfer of ARGs, which was related to the concentration and particle size. Compared with the control group, the transfer frequency was 95.5, 74.7, 65.4, 14.7, and 3.8 times higher in G (graphene), CB (carbon black), NGP (nanographite powder), GP1.6 (graphite powder 1.6 micron), and GP45 (graphite powder 45 micron) groups, respectively. Moreover, the transfer frequency gradually increased with the increase in CPM concentration, while there was a negative relationship between the CPM particle size and conjugative transfer frequency. In addition, the results showed that CPM could promote the transfer of ARGs by increasing ROS, as well as activating the SOS response and expression of conjugative transfer-related genes (trbBp, trfAp, korA, kroB, and trbA). These findings are indicative of the potential risk of CPM for the transfer of ARGs in the environment, enriching our understanding of environmental pollution and further raising awareness of environmental protection.

Simulated Gastric Acid Promotes the Horizontal Transfer of Multidrug Resistance Genes across Bacteria in the Gastrointestinal Tract at Elevated pH Levels.

The assessment of factors that can promote the transmission of antibiotic resistance genes (ARGs) across bacteria in the gastrointestinal tract is in great demand to understand the occurrence of infections related to antibiotic-resistant bacteria (ARB) in humans. However, whether acid-resistant enteric bacteria can promote ARG transmission in gastric fluid under high-pH conditions remains unknown. This study assessed the effects of simulated gastric fluid (SGF) at different pH levels on the RP4 plasmid-mediated conjugative transfer of ARGs. Moreover, transcriptomic analysis, measurement of reactive oxygen species (ROS) levels, assessment of cell membrane permeability, and real-time quantitative assessment of the expression of key genes were performed to identify the underlying mechanisms. The frequency of conjugative transfer was the highest in SGF at pH 4.5. Antidepressant consumption and certain dietary factors further negatively impacted this situation, with 5.66-fold and 4.26-fold increases in the conjugative transfer frequency being noted upon the addition of sertraline and 10% glucose, respectively, compared with that in the control group without any additives. The induction of ROS generation, the activation of cellular antioxidant systems, increases in cell membrane permeability, and the promotion of adhesive pilus formation were factors potentially contributing to the increased transfer frequency. These findings indicate that conjugative transfer could be enhanced under certain circumstances in SGF at elevated pH levels, thereby facilitating ARG transmission in the gastrointestinal tract. IMPORTANCE The low pH of gastric acid kills unwanted microorganisms, in turn affecting their inhabitation in the intestine. Hence, studies on the factors that influence antibiotic resistance gene (ARG) propagation in the gastrointestinal tract and on the underlying mechanisms are limited. In this study, we constructed a conjugative transfer model in the presence of simulated gastric fluid (SGF) and found that SGF could promote the dissemination of ARGs under high-pH conditions. Furthermore, antidepressant consumption and certain dietary factors could negatively impact this situation. Transcriptomic analysis and a reactive oxygen species assay revealed the overproduction of reactive oxygen species as a potential mechanism by which SGF could promote conjugative transfer. This finding can help provide a comprehensive understanding of the bloom of antibiotic-resistant bacteria in the body and create awareness regarding the risk of ARG transmission due to certain diseases or an improper diet and the subsequent decrease in gastric acid levels.

Predicting the concentrations of enteric viruses in urban rivers running through the city center via an artificial neural network.

Viral waterborne diseases are widespread in cities due largely to the occurrence of enteric viruses in urban rivers, which pose a significant concern to human health. Yet, the application of rapid detection technology for enteric viruses in environmental water remains undeveloped globally. Here, multiple linear regression (MLR) modeling and artificial neural network (ANN) modeling, which used frequently measured physicochemical parameters in river water, were constructed to predict the concentration of enteric viruses including human enteroviruses (EnVs), rotaviruses (HRVs), astroviruses (AstVs), noroviruses GⅡ (HuNoVs GⅡ), and adenoviruses (HAdVs) in rivers. After training, testing, and validating, ANN models showed better performance than any MLR model for predicting the viral concentration in Jinhe River. All determined R-values for ANN models exceeded 0.89, suggesting a strong correlation between the predicted and measured outputs for target enteric viruses. Furthermore, ANN models provided a better congruence between the observed and predicted concentrations of each virus than MLR models did. Together, these findings strongly suggest that ANN modeling can provide more accurate and timely predictions of viral concentrations based on frequent (or routine) measurements of physicochemical parameters in river water, which would improve assessments of waterborne disease prevalence in cities.

Visual Detection of Vibrio parahaemolyticus using Combined CRISPR/Cas12a and Recombinase Polymerase Amplification.

Objective: To establish an ultra-sensitive, ultra-fast, visible detection method for Vibrio parahaemolyticus (VP) . Methods: We established a new method for detecting the tdh and trh genes of VP using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 12a (CRISPR/Cas12a) combined with recombinase polymerase amplification and visual detection (CRISPR/Cas12a-VD). Results: CRISPR/Cas12a-VD accurately detected target DNA at concentrations as low as 10 -18 M (single molecule detection) within 30 min without cross-reactivity against other bacteria. When detecting pure cultures of VP, the consistency of results reached 100% compared with real-time PCR. The method accurately analysed pure cultures and spiked shrimp samples at concentrations as low as 10 2 CFU/g. Conclusion: The novel CRISPR/Cas12a-VD method for detecting VP performed better than traditional detection methods, such as real-time PCR, and has great potential for preventing the spread of pathogens.

Antibiotic resistance genes in gut of breast-fed neonates born by caesarean section originate from breast milk and hospital ward air.

The human gut is a reservoir of antibiotic resistance genes (ARGs). Even in the absence of antibiotics, ARGs are present in large quantities in faeces of adults, children and even newborns. However, where and when ARGs are acquired remains unclear, as does the types of ARGs acquired. Herein, we recruited 82 pairs of women and their caesarean section newborns. Conventional culture methods and quantitative PCR were employed to detect nine species and six ARG types in meconia, faeces from 3-day-old newborns, amniotic fluid, colostrum, and hospital ward air samples. Furthermore, ARG transfer was explored by tracking Staphylococcus epidermidis isolated from faeces of 3-day-old newborns, colostrum and ward air samples using multi-locus sequence typing (MLST). No ARGs or microorganisms were detected in meconia or amniotic fluid. One or more ARGs were detected in 90.2% of faeces from 3-day-old newborns, and the mecA gene exhibited the highest detection rate (45.1%). ARGs were detected in 85.4% of colostra consistent with ARGs in faeces from 3-day-old newborns. Some ARGs were detected in ward air, and might also be a source of ARGs in neonatal faeces. Isolation of S. epidermidis from neonatal faeces was consistent with antibiotic resistance and gene profiles for colostrum samples. Traceability analysis of S. epidermidis showed that ARGs in neonatal faeces mainly originated from colostrum, and partly from ward air. After birth, neonates born by caesarean section obtain a variety of ARGs mainly from colostrum, and partly from ward air.

[Regulative effect of active components of Cistanche deserticola on intestinal dysbacteriosis induced by antibiotics in mice].

Objective: To study the effects of Cistanche deserticola and its active components Cistanche deserticola polysaccharide and Echinacoside on intestinal flora of antibiotic-associated diarrhea (AAD) mice. Methods: Forty-eight Balb/c mice were randomly divided into control (Con) group, AAD Group, inulin (Inu) group, Cistanche deserticola (RCR) group, Cistanche deserticola polysaccharide (RCRDT) group and Echinacoside (Ech) group with 8 mice in each group. The diarrhea model of mice was induced by intragastric administration of lincomycin hydrochloride(3 g/kg) for 7 days, and then treated by intragastric administration of INU(5 g/kg), RCR(5 g/kg), RCRDT(200 mg/kg) and ECH (60 mg/kg),0.2 ml once a day for 7 days, Con group and AAD group were given the same volume of normal saline. By observing general signs of mice, colon HE staining, 16S rDNA high-throughput sequencing analysis, the effects of Cistanche deserticola, Cistanche deserticola polysaccharide and Echinacea glycoside on the imbalance of intestinal flora induced by antibiotics in mice were evaluated. Results: Compared with Con group, AAD group mice lost weight, presented obvious diarrhea symptoms, inflammatory changes in colon tissue and decreased intestinal flora diversity (P＜0.05) indicating the success of the model. Compared with AAD group, the weight and diarrhea of INU, RCR, RCRDT and ECH groups were significantly improved, and the colon pathology of ECH group was restored to normal level. Compared with AAD group, RCR group, RCRDT group and ECH group had significantly decreased intestinal Firmicutes, increased Blautia and Lachnoclostridium, and decreased Clostridium_sensu_stricto_1 (P＜0.05) . In ECH group, the abundance and diversity of intestinal microflora were returned to normal level, and the structure of intestinal microflora was well adjusted, the contents of Bacteroides, Flavonifractor, Agathobacter, Lachnoclostridium and Prevotella-9 were increased (P＜0.01). Conclusion: Both Cistanche deserticola and its active components cistanche deserticola polysaccharide and echinacoside can regulate the intestinal flora imbalance caused by antibiotics and improve the symptoms of AAD, especially echinacoside.

Spatial behavior and source tracking of extracellular antibiotic resistance genes in a chlorinated drinking water distribution system.

Antibiotic resistance genes (ARGs) are receiving increasing concerns due to the antibiotic resistance crisis. Nevertheless, little is known about the spatial behavior and sources of extracellular ARGs (eARGs) in the chlorinated drinking water distribution systems (DWDSs). Here, tap water was continuously collected to reveal the occurrence of both eARGs and intracellular ARGs (iARGs) along a chlorinated DWDS. Afterward, the correlation between eARGs, eDNA-releasing communities, and communities of planktonic bacteria was further analyzed. The eARG concentration decreased significantly, whereas the proportion of vanA and blaNDM-1 increased. Further, the diversity of the eDNA-releasing community increased markedly with increasing distance from the drinking water treatment plant (DWTP). Moreover, the dominant eDNA-releasing bacteria shifted from Acinetobacter, Pseudomonas, and Methylobacterium-Methylorubrum in finished water from the DWTP to Bacteroides, Faecalibacterium, Staphylococcus, and Parabacteroides in the DWDS. In terms of eARG source, thirty genera were significantly correlated with seven types of eARGs that resulted from the lysis of dead planktonic bacteria and detached biofilms. Conversely, the iARGs concentration increased, whereas the biodiversity of the planktonic bacteria community decreased in the sampling points along the DWDSs. Our findings provide critical insights into the spatial behavior and sources of eARGs, highlighting the health risks associated with ARGs in DWDSs.

[Effects of Chlorine Dioxide Disinfection on the Profile of the Super Antibiotic Resistance Genes in a Wastewater Treatment Plant].

In order to study the effects of chlorine dioxide (ClO2) disinfection on the super antibiotic resistance genes (SARGs), the final effluents before and after chlorine dioxide were sampled throughout one year in a wastewater treatment plant (WWTP). The bacteria and extracellular nucleic acid were collected using microporous membrane filtration and nucleic acid adsorption particles, respectively. A total of 9 SARGs was detected through a quantitative real-time polymerase chain reaction (qPCR). The results revealed that both intracellular and extracellular NDM-1, MCR-1, and MEC-A could be positively detected in the samples. Overall, ClO2 disinfection enhanced the relative abundance of the iSARGs (P<0.05), exhibiting a seasonal pattern, and increasing in the spring, summer, and autumn. In spring, it improved the most, up to twice the abundance. No SARGs were detected positive in the winter, either intracellularly or extracellularly. There was no significant variation in the concentrations of eSARGs before and after ClO2 disinfection. Therefore, ClO2 disinfection cannot effectively remove iSARGs and eSARGs in the final effluent from the WWTP.

Decreased Antibiotic Susceptibility in Pseudomonas aeruginosa Surviving UV Irradition.

Given its excellent performance against the pathogens, UV disinfection has been applied broadly in different fields. However, only limited studies have comprehensively investigated the response of bacteria surviving UV irradiation to the environmental antibiotic stress. Here, we investigated the antibiotic susceptibility of Pseudomonas aeruginosa suffering from the UV irradiation. Our results revealed that UV exposure may decrease the susceptibility to tetracycline, ciprofloxacin, and polymyxin B in the survival P. aeruginosa. Mechanistically, UV exposure causes oxidative stress in P. aeruginosa and consequently induces dysregulation of genes contributed to the related antibiotic resistance genes. These results revealed that the insufficient ultraviolet radiation dose may result in the decreased antibiotic susceptibility in the pathogens, thus posing potential threats to the environment and human health.

Contamination sources of the enteric virus in recreational marine water shift in a seasonal pattern.

Human enteric virus occurrence in bathing beaches poses a potential health risk to swimmers. They may come from several sources, but the understanding of the seasonal contribution of contamination sources to virus occurrence is still lacking. Here, the surveillance of human enteric viruses at the First Bathing Beach in Qingdao was performed January-December 2018. The occurrence of Enteric viruses, assayed with quantitative polymerase chain reaction (qPCR), was analyzed at temporal and spatial levels to determine the viral contamination sources. The results showed that only Astroviruses (AstVs) and Adenoviruses (HAdVs) were found in the swimming area. Their occurrence correlated significantly with the sewage-polluted area, but HAdVs were only found in autumn and AstVs in spring. Meanwhile, enteric viruses in the swimming area showed significantly higher levels than the surrounding area, particularly AstVs in summer with the swimmer crowd. All these data imply that sewage discharge and swimmers co-contribute to the viral occurrence in a seasonal pattern, with the former being more focused in warm seasons (spring and autumn) and the latter in hot seasons (summer). These results indicate that sewage discharge and crowd swimmers, as unsafe swimming conditions, should be avoided to improve public health at the bathing beaches.

Chlorine disinfection promotes the exchange of antibiotic resistance genes across bacterial genera by natural transformation.

Chlorine disinfection to drinking water plays an important role in preventing and controlling waterborne disease outbreaks globally. Nevertheless, little is known about why it enriches the antibiotic resistance genes (ARGs) in bacteria after chlorination. Here, ARGs released from killed antibiotic-resistant bacteria (ARB), and culturable chlorine-injured bacteria produced in the chlorination process as the recipient, were investigated to determine their contribution to the horizontal transfer of ARGs during disinfection treatment. We discovered Escherichia coli, Salmonella aberdeen, Pseudomonas aeruginosa and Enterococcus faecalis showed diverse resistance to sodium hypochlorite, and transferable RP4 could be released from killed sensitive donor consistently. Meanwhile, the survival of chlorine-tolerant injured bacteria with enhanced cell membrane permeabilisation and a strong oxidative stress-response demonstrated that a physiologically competent cell could be transferred by RP4 with an improved transformation frequency of up to 550 times compared with the corresponding untreated bacteria. Furthermore, the water quality factors involving chemical oxygen demand (CODMn), ammonium nitrogen and metal ions (Ca2+ and K+) could significantly promote above transformation frequency of released RP4 into injured E. faecalis. Our findings demonstrated that the chlorination process promoted the horizontal transfer of plasmids by natural transformation, which resulted in the exchange of ARGs across bacterial genera and the emergence of new ARB, as well as the transfer of chlorine-injured opportunistic pathogen from non-ARB to ARB. Considering that the transfer elements were quite resistant to degradation through disinfection, this situation poses a potential risk to public health.

Putative environmental levels of levofloxacin facilitate the dissemination of antibiotic-resistant Escherichia coli via plasmid-mediated transformability.

Antibiotic residues in the environment pose a great risk to global public health. They increase antibiotic resistance by enhancing plasmid conjugation among bacteria or mutations within bacterial genomes. However, little is known about whether the putative environmental levels of antibiotics are sufficient to influence plasmid-mediated transformability. In this study, we explored the effect of eight kinds of representative antibiotics and several other compounds on the plasmid transformability of competent Escherichia coli. Only levofloxacin (LEV) at the putative environmental levels was found to facilitate the frequency of PBR322-or RP4-plasmid-mediated transformation by up to 5.3-fold. Additionally, PBR322 transformation frequency could be further enhanced by copper ion or ammonia nitrogen but inhibited by humic acid. However, when competent E. coli was exposed to the minimal inhibitory concentrations (MIC) of the antibiotics, an enhanced plasmid-assimilation ability was observed and plasmid transformation frequency was increased by up to 98.6-fold for all the tested antibiotics. Furthermore, E. coli exhibited a preference for the uptake of plasmids harbouring the resistance genes to the antibiotics it had been exposed to. Among these antibiotics, cephalexin, tetracycline, and kanamycin induced the highest uptake of RP4. The putative environmental levels of LEV enhanced plasmid transformability regardless of the presence of corresponding antibiotic resistance gene (ARG) on the genetic elements, suggesting environmental LEV residues may facilitate dissemination of antibiotic resistance by any plasmid-mediated transformability, thereby posing a great risk to health.

[Simultaneous determination of three antidepressant drugs in feces by HLPC-MS].

Objective: To establish a high performance liquid chromatography tandem mass spectrometry (HPLC / MS) method for the simultaneous determination of three antidepressant drugs in feces. Methods: Samples were pretreated with n-hexane isopropanol (95:5, v/v). Gradient elution was carried out with mixed liquid of ultrapure water and acetonitrile as mobile phase and separated by Agilent ZORBAX SB-C18 liquid chromatography column (2.1 mm×100 mm, 3.5 m). The samples were detected by electrospray ionization tandem mass spectrometry and quantified by internal standard method. Results: The recoveries of duloxetine, fluoxetine and escitalopram in fecal samples were 61.6% - 116.5%, with precision of 2.80% - 12.9% (n=5). The correlation coefficients (r) of linear equations were all greater than 0.995. The detection limits were 0.1, 1, and 0.001 µg/g, and the limits of quantification were 0.5, 2 and 0.005 µg/g, respectively. Conclusion: The method is simple and accurate to detect the contents of three antidepressants in feces, such as duloxetine, fluoxetine and escitalopram.

Graphene oxide composites for magnetic solid-phase extraction of twelve quinolones in water samples followed by MALDI-TOF MS.

Antibiotic compounds in natural waters are normally present at low concentrations. In this paper, an easy and highly sensitive screening method using graphene oxide-functionalized magnetic composites (GO@NH2@Fe3O4) combined with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was established for twelve quinolone antibiotics. GO@NH2@Fe3O4 composites were utilized as adsorbents for magnetic solid-phase extraction. This method combines the advantages of magnetic solid-phase extraction and MALDI-TOF MS, which allows for fast detection of quinolones at low concentrations. To improve absorption efficiency, the following parameters were individually optimized: sample acidity, extraction time, amount of adsorbent used, eluent used, and desorption time. Under the optimum conditions, the established method gave a low detection limit of 0.010 mg/L and allowed the high-throughput screening of twelve quinolone antibiotics (enoxacin, norfloxacin, ciprofloxacin, pefloxacin, fleroxacin, gatifloxacin, enrofloxacin, levofloxacin, sparfloxacin, danofloxacin, difloxacin, and lomefloxacin). The proposed method, having an easily prepared sorbent with a high affinity for quinolones and a convenient, high-throughput detection step, has been shown to have merit for the detection of antibiotics in water samples. Graphical abstract Schematic illustration of the (A) preparation of GO@NH2@Fe3O4 and (B) operating procedure for the MSPE and MALDI-TOF MS detection of QNs.

Inactivation of Poliovirus by Ozone and the Impact of Ozone on the Viral Genome.

OBJECTIVE: To investigate the mechanisms underlying ozone-induced inactivation of poliovirus type 1 (PV1). METHODS: We used cell culture, long-overlapping RT-PCR, and spot hybridization assays to verify and accurately locate the sites of action of ozone that cause PV1 inactivation. We also employed recombinant viral genome RNA infection models to confirm our observations. RESULTS: Our results indicated that ozone inactivated PV1 primarily by disrupting the 5'-non-coding region (5'-NCR) of the PV1 genome. Further study revealed that ozone specifically damaged the 80-124 nucleotide (nt) region in the 5'-NCR. Recombinant viral genome RNA infection models confirmed that PV1 lacking this region was non-infectious. CONCLUSION: In this study, we not only elucidated the mechanisms by which ozone induces PV1 inactivation but also determined that the 80-124 nt region in the 5'-NCR is targeted by ozone to achieve this inactivation.

Chlorine injury enhances antibiotic resistance in Pseudomonas aeruginosa through over expression of drug efflux pumps.

Adaption to adverse environments plays an important role in bacterial survival and is receiving increasing globe attention now. Here, cultivable chlorine-injured Pseudomonas aeruginosa, produced on the chlorination process, was investigated about their resistance to antibiotics. Then, global transcriptional analyses, quantitative PCR (qPCR) validation and antioxidant enzymes measurement were performed to explore the underlying mechanisms. The results showed that chlorine injury enhanced antibiotic resistance in P. aeruginosa and cultivable chlorine-injured P. aeruginosa exposed to 4 mg/L sodium hypochlorite (half of the lethal dose) improved antibiotic resistance against ceftazidime, chloramphenicol and ampicillin by 1.4-5.6 fold. This increase in antibiotic resistance was not hereditable and over expression of the MexEF-OprN efflux pump resulting from oxidative stress contributed to it. These results demonstrate temporal physiological persistence to antibiotics in cultivable chlorine-injured pathogens, suggesting their survival from adverse environments with antibiotic exposure and thereby posing lasting hazards to human health.

QTL mapping and genetic effect of chromosome segment substitution lines with excellent fiber quality from Gossypium hirsutum × Gossypium barbadense.

Chromosome segment substitution lines (CSSLs) are ideal materials for identifying genetic effects. In this study, CSSL MBI7561 with excellent fiber quality that was selected from BC4F3:5 of CCRI45 (Gossypium hirsutum) × Hai1 (Gossypium barbadense) was used to construct 3 secondary segregating populations with 2 generations (BC5F2 and BC5F2:3). Eighty-one polymorphic markers related to 33 chromosome introgressive segments on 18 chromosomes were finally screened using 2292 SSR markers which covered the whole tetraploid cotton genome. A total of 129 quantitative trait loci (QTL) associated with fiber quality (103) and yield-related traits (26) were detected on 17 chromosomes, explaining 0.85-30.35% of the phenotypic variation; 39 were stable (30.2%), 53 were common (41.1%), 76 were new (58.9%), and 86 had favorable effects on the related traits. More QTL were distributed in the Dt subgenome than in the At subgenome. Twenty-five stable QTL clusters (with stable or common QTL) were detected on 22 chromosome introgressed segments. Finally, the 6 important chromosome introgressed segments (Seg-A02-1, Seg-A06-1, Seg-A07-2, Seg-A07-3, Seg-D07-3, and Seg-D06-2) were identified as candidate chromosome regions for fiber quality, which should be given more attention in future QTL fine mapping, gene cloning, and marker-assisted selection (MAS) breeding.

Transcriptomic and biochemical analysis of upland cotton (Gossypium hirsutum) and a chromosome segment substitution line from G. hirsutum × G. barbadense in response to Verticillium dahliae infection.

BACKGROUND: Verticillium wilt (VW), also known as "cotton cancer," is one of the most destructive diseases in global cotton production that seriously impacts fiber yield and quality. Despite numerous attempts, little significant progress has been made in improving the VW resistance of upland cotton. The development of chromosome segment substitution lines (CSSLs) from Gossypium hirsutum × G. barbadense has emerged as a means of simultaneously developing new cotton varieties with high-yield, superior fiber, and resistance to VW. RESULTS: In this study, VW-resistant investigations were first conducted in an artificial greenhouse, a natural field, and diseased nursery conditions, resulting in the identification of one stably VW-resistant CSSL, MBI8255, and one VW-susceptible G. hirsutum, CCRI36, which were subsequently subjected to biochemical tests and transcriptome sequencing during V991 infection (0, 1, and 2 days after inoculation). Eighteen root samples with three replications were collected to perform multiple comparisons of enzyme activity and biochemical substance contents. The findings indicated that VW resistance was positively correlated with peroxidase and polyphenol oxidase activity, but negatively correlated with malondialdehyde content. Additionally, RNA sequencing was used for the same root samples, resulting in a total of 77,412 genes, of which 23,180 differentially expressed genes were identified from multiple comparisons between samples. After Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis on the expression profiles identified using Short Time-series Expression Miner, we found that the metabolic process in the biological process, as well as the pathways of phenylpropanoid biosynthesis and plant hormone signal transduction, participated significantly in the response to VW. Gene functional annotation and expression quantity analysis indicated the important roles of the phenylpropanoid metabolic pathway and oxidation-reduction process in response to VW, which also provided plenty of candidate genes related to plant resistance. CONCLUSIONS: This study concentrates on the preliminary response to V991 infection by comparing the VW-resistant CSSL and its VW-susceptible recurrent parent. Not only do our findings facilitate the culturing of new resistant varieties with high yield and superior performance, but they also broaden our understanding of the mechanisms of cotton resistance to VW.

Hepatitis C virus infection induces endoplasmic reticulum stress and apoptosis in human fetal liver stem cells.

The cellular mechanisms by which hepatitis C virus (HCV) replication might mediate cytopathic effects are controversial and not entirely clear. In this study, we found that blood-borne HCV (bbHCV) infection could lead to endoplasmic reticulum (ER)-stress and mitochondria-related/caspase-dependent apoptosis at the early stages of infection based on use of the highly efficient bbHCV cell culture model established previously. Sections of bbHCV-infected human fetal liver stem cells (hFLSCs) revealed convolution and nonlinear ER, cell vacuolization, swelling of mitochondria, and numerous double membrane vesicles (DMVs). The percentage of apoptotic hFLSCs infected by bbHCV reached 29.8% at 16 h postinfection, and the amount of cytochrome c increased remarkably in the cytosolic protein fraction. However, over time, apoptosis was inhibited due to the activation of NF-κB. The expression of NF-κB-p65, Bcl-xL, XIAP, and c-FLIPL in hFLSCs was increased significantly 24 h after in infection by bbHCV. The accelerated cell death cycles involving apoptosis, regeneration and repair by bbHCV infection might give rise to the development of cirrhosis, and ultimately to hepatocellular carcinogenesis. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Profiling of intracellular and extracellular antibiotic resistance genes in tap water.

Antibiotic resistance genes (ARGs) have gained global attention due to their public health threat. Extracelluar ARGs (eARGs) can result in the dissemination of antibiotic resistance via free-living ARGs in natural environments, where they promote ARB transmission in drinking water distribution systems. However, eARG pollution in tap water has not been well researched. In this study, concentrations of eARGs and intracellular ARGs (iARGs) in tap water, sampled at Tianjin, China, were investigated for one year. Fourteen eARG types were found at the highest concentration of 1.3 × 105 gene copies (GC)/L. TetC was detected in 66.7% of samples, followed by sul1, sul2, and qnrA with the same detection frequency of 41.7%. Fifteen iARGs (including tetA, tetB, tetM, tetQ, tetX, sul1, sul2, sul3, ermB, blaTEM, and qnrA) were continuously detected in all collected tap water samples with sul1 and sul2 the most abundant. Additionally, both eARG and iARG concentrations in tap water presented a seasonal pattern with most abundant prevalence in summer. The concentration of observed intracellular sulfonamide resistance genes showed a significantly positive correlation with total nitrogen concentrations. This study suggested that eARG and iARG pollution of drinking water systems pose a potential risk to human public health.