Effects of evidence-based care on diabetic foot ulcers: A meta-analysis.

This analysis systematically reviewed the efficacy of evidence-based care on diabetic foot ulcers. A computerised literature search was conducted for randomised controlled studies (RCTs) of evidence-based care interventions for the treatment of diabetic foot ulcers using the PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM) and Wanfang databases from the date of inception of each database to June 2023. The articles were independently screened, data were extracted by two researchers, and the quality of each study was assessed using the Cochrane bias assessment tool. Meta-analysis of the data was performed using RevMan 5.4 software. Twenty-five RCTs with a total of 2272 patients were included. Meta-analysis showed that, compared with other care methods, evidence-based care significantly improved the treatment efficacy of diabetic foot ulcers (odds ratio: 3.91, 95% confidence interval [CI]: 2.76 to 5.53, p < 0.001) and significantly reduced their fasting plasma glucose (mean difference [MD]: -1.10, 95% CI: -1.24 to -0.96, p < 0.001), 2-h postprandial glucose (2hPG) (MD: -1.69, 95% CI: -2.07 to -1.31, p < 0.001) and glycated haemoglobin (HbA1c) (MD: -0.71, 95% CI: -0.94 to -0.48, p < 0.001). Evidence-based care intervention is effective at reducing FPG, 2hPG and HbA1c levels and improving treatment efficacy in patients with diabetic foot ulcers.

Substrate-Controlled Diversity-Oriented Synthesis of Novel Polycyclic Frameworks via [4 + 2] and [3 + 2] Annulations of Ninhydrin-Derived MBH Adducts with 3,4-Dihydroisoquinolines.

Substrate-controlled diversity-oriented synthesis of polycyclic frameworks via [4 + 2] and [3 + 2] annulations between ninhydrin-derived Morita-Baylis-Hillman (MBH) adducts and 3,4-dihydroisoquinolines under similar reaction conditions have been developed. The reaction provides diversity-oriented synthesis of a series of novel and structurally complex spiro multi heterocyclic skeletons in good yields (up to 87% and 90%, respectively) with excellent diastereoselectivities (up to >25:1 dr). In particular, the switchable [4 + 2] and [3 + 2] annulation reactions are controlled by tuning the hydroxyl protecting group on the ninhydrin-derived MBH adduct to deliver structural diverse spiro[indene-2,2'-[1,3]oxazino[2,3-a]isoquinoline] and spiro[indene-2,1'-pyrrolo[2,1-a]isoquinoline], respectively. Furthermore, the relative configuration and chemical structure of two kinds of cycloadducts were confirmed through X-ray diffraction analysis.

The effects of enhanced recovery after surgery on wound infection, complications, and postoperative hospital stay in patients undergoing colorectal surgery: A systematic review and meta-analysis.

This study aimed to systematically evaluate the effects of enhanced recovery after surgery (ERAS) on surgical site infections, postoperative complications, and length of hospital stay in patients undergoing colorectal surgery. A comprehensive search was conducted of PubMed, Web of Science, Ovid, EMBASE, The Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Data from database inception to April 2023 to identify relevant studies on the application of ERAS in colorectal surgery. Studies were screened, and data were extracted based on predetermined inclusion and exclusion criteria. Meta-analysis was performed using RevMan 5.4 software. A total of 22 studies, including 3702 patients (ERAS group: 1906; control group: 1796), were included in the final analysis. ERAS significantly reduced the incidence of surgical site infection (odds ratio [OR]: 0.49, 95% confidence interval [CI]: 0.34-0.69, p < 0.001), postoperative complications (OR: 0.33, 95% CI: 0.27-0.41, p < 0.001), and length of hospital stay (standardised mean difference: -1.22 days, 95% CI: -1.66 to -0.77 days, p < 0.001). These findings suggest that ERAS reduces the incidence of surgical site infections and postoperative complications and shortens the length of hospital stay in patients undergoing colorectal surgery. Therefore, ERAS should be promoted and applied in clinical practice.

Direct ferrous sulfate exposure facilitates the VBNC state formation rather than ferroptosis in Listeria monocytogenes.

Listeria monocytogenes frequently causes Listeriosis in humans and animals. In present study, we discovered that in the presence of FeSO4, L. monocytogenes became viable but non-culturable (VBNC), and remained virulent to Caenorhabditis elegans. The killing assay indicated that these VBNC cells kept sensitive to tetracycline, differing from dormant cells. Transcriptomic analysis revealed more gene transcription occurrence in the VBNC cells compared to dormant cells, involving stress response and ribosome binding. No ferroptosis hallmarks were observed in the VBNC cells, whereas the application of either intracellular Fe2+ chelator or the ferroptosis inhibitor arrested the formation of VBNC state by FeSO4, as well as by Benzakonium chloride or Haz-Tab. This implicated the universal involvement of intracellular Fe2+ and other cascades related to ferroptosis in the formation of VBNC state in L. monocytogenes. Taken together, we discovered an iron-induced VBNC state in L. monocytogenes, and provided clues to further understanding their potential risks.

ER stress-related mRNA-lncRNA co-expression gene signature predicts the prognosis and immune implications of esophageal cancer.

BACKGROUND: Esophageal cancer (EC) is one of the most common malignant cancers in the world. Endoplasmic reticulum (ER) stress is an adaptive response to various stress conditions and has been implicated in the development of various types of cancer. Long noncoding RNAs (lncRNAs) refer to a group of noncoding RNAs (ncRNAs), which regulate gene expression by interacting with DNA, RNA and proteins. Accumulating evidence suggests that lncRNAs are critical regulators of gene expression in development, differentiation, and human diseases, such as cancers and heart diseases. However, the prognostic model of EC based on ER stress-related mRNA and lncRNA has not been reported. METHODS: Firstly, we downloaded RNA expression profiles from The Cancer Genome Atlas (TCGA) and obtained ER stress-related genes from the Molecular Signature Database (MSigDB). Next, Weighted Correlation Network Analysis (WGCNA) co-expression analysis was used to identify survival-related ER stress-related modules. Prognostic models were developed using univariate and Least absolute shrinkage and selection operator (LASSO) regression analyses on the training set and validated on the test set. Afterwards, The Receiver Operating Characteristic (ROC) curve and nomogram were used to evaluate the performance of risk prediction models. Differentially expressed gene (DEG) and enrichment analysis were performed between different groups in order to identify the biological processes correlated with the risk score. Finally, the fraction of immune cell infiltration and the difference of tumor microenvironment were identified in high-risk and low-risk groups. RESULTS: The WGCNA co-expression analysis identified 49 ER genes that are highly associated with EC prognosis. Using univariate Cox regression and LASSO regression analysis, we developed prognostic risk models based on nine signature genes (four mRNAs and five lncRNAs). Both in the training and in the test sets, the overall survival (OS) of EC patients in the high-risk group was significantly lower than that in the low-risk group. The Kaplan-Meier curve and the ROC curve demonstrate the prognostic model we built can precisely predict the survival with more than 70% accuracy. The correlation analysis between the risk score and the infiltration of immune cells showed that the model can indicate the state of the immune microenvironment in EC. CONCLUSION: In this study, we developed a novel prognostic model for esophageal cancer based on ER stress-related mRNA-lncRNA co-expression profiles that could predict the prognosis, immune cell infiltration, and immunotherapy response in patients with EC. Our results also may provide clinicians with a quantitative tool to predict the survival time of patients and help them individualize treatment strategies for the patients with EC.

Construction and validation of a prognostic model for lung adenocarcinoma based on endoplasmic reticulum stress-related genes.

Lung adenocarcinoma (LUAD) is one of the most universal types of cancer all over the world and its morbidity continues to rise year by year. Growing evidence has demonstrated that endoplasmic reticulum stress is highly activated in cancer cells and plays a key role in regulating the fate of cancer cells. However, the role and mechanism of endoplasmic reticulum stress in lung adenocarcinoma genesis and development remains unclear. In this research, we developed a prognostic model to predict the overall survival of patients with LUAD utilizing endoplasmic reticulum stress-related genes and screened out potential small molecular compounds, which could assist the clinician in making accurate decisions and better treat LUAD patients. Firstly, we downloaded 419 endoplasmic reticulum stress-related genes (ERSRGs) from Molecular Signatures Database (MSigDB). Secondly, we obtained information about the transcriptome profiling and corresponding clinical data of 59 normal samples and 535 lung adenocarcinoma samples from The Cancer Genome Atlas (TCGA) database. Next, we used the DESeq2 package to identify differentially expressed genes related to endoplasmic reticulum stress. We performed univariate Cox, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analysis to establish a prognostic model for LUAD patients based on ERSRGs. Then, we carried out univariate and multivariate independent prognostic analysis of endoplasmic reticulum stress-related gene (ERSRG) score and some clinical traits of lung adenocarcinoma. Additionally, we developed a clinically applicable nomogram for predicting survival for LUAD patients over one, three, and five years. Moreover, we carried out a drug sensitivity analysis to identify novel small molecule compounds for LUAD treatment. Finally, we examined the tumor microenvironment (TME) and immune cell infiltrating analysis to explore the interactions between immune and cancer cells. 142 differentially expressed ERSRGs were identified by using the DESeq2 package. A prognostic model was built based on 7 differentially expressed ERSRGs after performing univariate Cox regression, LASSO regression, and multivariate Cox regression analysis. According to the results of univariate and multivariate independent prognostic analysis, we found ERSRG score can be used as an independent prognostic maker. Using the Kaplan-Meier curves, we found low-risk patients had higher survival probability than high-risk patients in both training set and test set. A nomogram was drawn to predict 1-, 3-, and 5-year survival probability. The calibration curves explained good performance of the model for the prediction of survival. Phenformin, OSU-03012, GSK-650394 and KIN001-135 were identified as the drugs most likely to provide important information to clinicians about the treatment of LUAD patients. A prognostic prediction model was established based on 7 differentially expressed ERSRGs (PDX1, IGFBP1, DDIT4, PPP1R3G, CFTR, DERL3 and NUPR1), which could effectively predict the prognosis of LUAD patients and give a reference for clinical doctors to help LUAD patients to make better treatment tactics. Based on the 4 small molecule compounds (Phenformin, OSU-03012, GSK-650394 and KIN001-135) we discovered, targeting endoplasmic reticulum stress-related genes may also be a therapeutic approach for LUAD patients.

Heat shock in Cronobacter sakazakii induces direct protection and cross-protection against simulated gastric fluid stress.

The bacterial heat shock response in foodborne pathogens is caused by exposure to higher temperatures which poses a great threat to food safety because it can undermine food processing interventions and host defense. The study assessed the heat and acid resistance of Cronobacter sakazakii following heat shock (53 °C for 15min). Inactivation curves of the heat-shocked and non-shocked C. sakazakii cells at four temperatures (56, 58, 60, and 62 °C) and simulated gastric fluid (SGF, pH 3.0) were examined and fitted with the log-linear model and the Weibull model. The inactivation parameters obtained on the basis of the Weibull model showed that heat shock significantly (p < 0.05) increased the values of δ (time to reach 1 log reduction) and t3d (time to reach 3 log reduction) under thermal and acid inactivation. The results proved that heat shock provided C. sakazakii direct protection from a more adverse heat challenge and cross-protection from SGF, i.e. there was a heat shock response. Results of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed that seven protein species showed enhanced expression, while four protein species showed decreased expression in the heat-shocked compared to the non-heat-shocked C. sakazakii cells. Quantitative real-time reverse transcriptase PCR (RT-qPCR) revealed upregulation of six stress related genes, ibpA, ibpB (both encoding molecular chaperons), Hsp15 (encoding heat shock protein), Hsp20 (encoding small heat-shock protein), HspQ (encoding proteases) and rpoS (encoding stationary phase sigma factor), following heat shock treatment. In addition, heat shock induced an increase proportion of saturated fatty acids (SFA), cyclic fatty acids (CFA) and the ratio of saturated fatty acids to unsaturated fatty acids (SFA/USFA), whereas reducing the proportion of unsaturated fatty acids (USFA). Consequently, establishment of inactivation models of C. sakazakii could provide data support for quantitative microbial risk assessment (QMRA). Exploration of enhanced resistance mechanisms might provide clues for prevention and control of contamination by heat-shocked C. sakazakii.

Quantitative Determination of Nitrofurazone Metabolites in Animal-Derived Foods Based on a Background Fluorescence Quenching Immunochromatographic Assay.

Due to their facile synthesis and friendly functionalization, gold nanoparticles (AuNPs) have been applied in all kinds of biosensors. More importantly, these biosensors, with the combination of AuNPs and immunoassay, are expected to be used for the detection of different compounds with low concentrations in complex samples. In this study, a AuNPs-labeled antibody immunoprobe was prepared and combined with a fluorescence-quenching principle and a background fluorescence-quenching immunochromatographic assay (bFQICA), achieving rapid on-site detection. By using a portable fluorescence immunoquantitative analyzer and a QR code with a built-in standard curve, the rapid quantitative determination for nitrofurazone metabolite of semicarbazide (SEM) in animal-derived foods was realized. The limits of detection (LODs) for bFQICA in egg, chicken, fish, and shrimp were 0.09, 0.10, 0.12, and 0.15 µg kg-1 for SEM, respectively, with the linear range of 0.08-0.41 µg L-1, the recoveries ranging from 73.5% to 109.2%, and the coefficient of variation <15%, only taking 13 min for the SEM detection. The analysis of animal-derived foods by bFQICA complied with that of liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Spectroscopic Characterization of a Polycaprolactone-Chitosan Electrospun Scaffold Modified with Photocatalytic TiO2 Nanoparticles for Improved Wound Healing: A Complete In Vivo Evaluation.

In the current study, we hypothesized that the electrospun scaffold chitosan (CS)/polycaprolactone (PCL)/titanium dioxide (TiO2) could be prepared by combining CS, PCL, and TiO2 nanoparticles (TiO2 NPs) using an electrospinning technique for wound dressing applications. The CS/PCL/TiO2 electrospun scaffold was prepared and characterized by UV-Vis, SEM, TEM, FTIR, and XRD analyses. Based on the UV-Vis analysis, the incorporation of CS/PCL on the surface of TiO2 NPs affected their optical properties. Further, CS/PCL and CS/PCL/TiO2 were found to have uniform distribution in fiber diameter with no bead morphology, as confirmed by SEM. The XRD spectrum of the CS/PCL/TiO2 revealed that the TiO2 NPs were adequately mixed with the CS/PCL solution, exhibiting the planes of TiO2 peaks (112), (105), (204), (116), and (301), which aligned well with the lattice structure. The antibacterial activity of CS/PCL/TiO2 against Staphylococcus aureus and Escherichia coli was evaluated using the zone of inhibition method. By testing the cytocompatibility of CS/PCL/TiO2 in vitro, this dressing was found to have a less toxic nature. In addition, In Vivo wound healing studies showed that the dressing prepared with the CS/PCL/TiO2 electrospun scaffold improved wound healing compared to that prepared with CS/PCL alone. The above results strongly support the use of CS/PCL/TiO2 electrospun scaffold as an effective dressing for wound healing.

Production and characterization of monoclonal antibodies against GII.6 norovirus virus-like particles.

In this study we generated and characterized a series of monoclonal antibodies (mAbs) against GII.6 norovirus (NoV) virus like particles (VLPs). Mice were immunized with purified GII.6 NoV VLPs and peptide-bovine serum albumin (BSA) conjugates with the peptide sequence (31 aa) derived from the trypsin cleavage region. An indirect enzyme-linked immunosorbent assay was used to identify positive cell clones during cloning and subcloning, and an in vitro VLP-histo-blood group antigens (HBGAs) binding blockade assay was used to identify mAbs with blocking ability. A total of seven mAbs comprising five (1F7, 1F11, 2B6, 2C4, and 2E10) reactive with major capsid proteins (VP1) and two (1E5 and 2B2) reactive with both VP1 proteins and the peptide were identified. mAb 1F7, 1F11, and 2B6 were identified as blocking antibodies. Sandwich ELISA indicated that all these mAbs recognized soluble GII.6 NoV VLPs. Cross-reactivities with GI.7, GII.3, and GII.4 NoV VLPs were observed in indirect and sandwich ELISA. Western blot analysis indicated that all non-blocking mAbs recognized denatured GII.6 VP1 proteins and blocking mAbs only recognized non-denatured proteins. The in vitro VLP-HBGA binding blockade assay indicated that the three blocking antibodies exhibited blocking effects against GII.6 NoV VLPs, but not GI.7, GII.3, and GII.4 NoV VLPs. Epitope mapping and HBGA blocking assay indicated that mAbs targeting the predicted surface-exposed loop region did not have blocking effects, suggesting a possible important role of this region in regulating NoV-HBGA interactions. This is the first report regarding the characterization of mAbs with blocking ability against GII.6 NoV VLPs. These mAbs might be useful in facilitating our understanding of this group of viruses.

Proteomic analysis of the antimicrobial effects of sublethal concentrations of thymol on Salmonella enterica serovar Typhimurium.

Salmonella enterica serovar Typhimurium is an important foodborne pathogen that causes serious and extensive food contamination as well as disease and death worldwide. Considering the increasing severity of antibiotic resistance, antibiotic alternatives are urgently needed. As a natural biocide and a component of some essential oils from herbs, thymol is capable of killing various bacteria through a potentially unique mechanism, although the targets of thymol have not been completely elucidated. In this study, the variation in the whole proteome of Salmonella after thymol stress was evaluated using the SWATH multiplex technique. The strain Salmonella Typhimurium CVCC541 was treated with a sublethal concentration (75 µg/mL) of thymol, which rapidly increased the permeability of bacterial membranes at the tested concentration. Thymol destroyed the integrity of the bacterial membrane, as observed by transmission electron microscopy. The proteomes of the treated and untreated cells were characterized after an 8-h treatment. The proteomic analysis of thymol-treated cells indicated that 144 proteins exhibited upregulation or downregulation compared with the control cells, particularly those involved in cellular structure and metabolism. The results of this study showed that thymol may play an antimicrobial role in altering the membrane permeability, virulence change, and antioxidant response of Salmonella Typhimurium. The results of the present study provide an improved understanding of the proteomic response of Salmonella Typhimurium to thymol stress, including the identification of promising targets for the future exploration of innovative approaches to control Salmonella Typhimurium.

Bactericidal activity of alpha-bromocinnamaldehyde against persisters in Escherichia coli.

Persisters are tolerant to multiple antibiotics, and widely distributed in bacteria, fungi, parasites, and even cancerous human cell populations, leading to recurrent infections and relapse after therapy. In this study, we investigated the potential of cinnamaldehyde and its derivatives to eradicate persisters in Escherichia coli. The results showed that 200 µg/ml of alpha-bromocinnamaldehyde (Br-CA) was capable of killing all E. coli cells during the exponential phase. Considering the heterogeneous nature of persisters, multiple types of persisters were induced and exposed to Br-CA. Our results indicated that no cells in the ppGpp-overproducing strain or TisB-overexpressing strain survived the treatment of Br-CA although considerable amounts of persisters to ampicillin (Amp) and ciprofloxacin (Cip) were induced. Chemical induction by carbonyl cyanide m-chlorophenylhydrazone (CCCP) led to the formation of more than 10% persister to Amp and Cip in the entire population, and Br-CA still completely eradicated them. In addition, the cells in the stationary phase, which are usually highly recalcitrant to antibiotics treatment, were also completely eradicated by 400 µg/ml of Br-CA. Further studies showed that neither thiourea (hydroxyl-radical scavenger) nor DPTA (Fe3+ chelator to block the hydroxyl-radical) affected the bactericidal efficiency of the Br-CA to kill E. coli, indicating a ROS-independent bactericidal mechanism. Taken together, we concluded that Br-CA compound has a novel bactericidal mechanism and the potential to mitigate antibiotics resistance crisis.

Preliminary study of urine metabolism in type two diabetic patients based on GC-MS.

OBJECTIVE: Comparative study of type 2 diabetes and healthy controls by metabolomics methods to explore the pathogenesis of Type II diabetes. METHODS: Gas chromatography - mass spectrometry (GC-MS) with a variety of multivariate statistical analysis methods to the healthy control group 58 cases, 68 cases of Type II diabetes group were analyzed. Chromatographic conditions: DB-5MS column; the carrier gas He; flow rate of 1 mL·min(-1), the injection volume 1 uL; split ratio is 100: 1. MS conditions: electron impact (EI) ion source, an auxiliary temperature of 280°C, the ion source 230°C, quadrupole 150°C; mass scan range 30~600 mAu. RESULTS: Established analytical method based on urine metabolomics GC-MS of Type II diabetes, determine the urine succinic acid, L-leucine, L-isoleucine, tyrosine, slanine, acetoace acid, mannose, L-isoleucine, L-threonine, Phenylalanine, fructose, D-glucose, palmi acid, oleic acid and arachidonic acid were significantly were significantly changed. CONCLUSION: Based on metabolomics of GC-MS detection and analysis metabolites can be found differences between type 2 diabetes and healthy control group, PCA diagram can effectively distinguish Type II diabetes and healthy control group, with load diagrams and PLS-DA VIP value metabolite screening, the resulting differences in metabolic pathways involved metabolites, including amino acid metabolism, lipid metabolism, glucose metabolism and energy metabolism.

Development of a class-specific polyclonal antibody-based indirect competitive ELISA for detecting fluoroquinolone residues in milk.

Modified 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) method was employed to synthesize the artificial antigen of norfloxacin (NOR), and New Zealand rabbits were used to produce anti-NOR polyclonal antibody (pAb). Based on the checkerboard titration, an indirect competitive enzyme-linked immunosorbent assay (icELISA) standard curve was established. This assay was sensitive and had a working range from 0.12 to 68.40 ng/ml, with the half maximal inhibitory concentration (IC(50)) and limit of detection (LOD) values of 2.7 ng/ml and 0.06 ng/ml, respectively. The produced pAb exhibited high cross-reactivity to fluoroquinolones (FQs) tested, and the IC(50) values to enoxacin, ciprofloxacin, and pefloxacin were 3.1, 3.4, and 4.1 ng/ml, respectively. It also indicated that the concentrations of NaOH and methanol in assay buffer should not be higher than 10% and 30%. When spiked in milk at 5, 20, and 50 ng/ml, the recoveries for NOR, enoxacin, ciprofloxacin, and pefloxacin ranged 90.5%-98.0%, 84.0%-95.2%, 94.0%-106.0%, and 89.5%-100.0%, respectively. The results suggest that this class-specific pAb-based icELISA could be utilized for the primary screening of FQ residues in animal-original products.

A survey of plasmid-mediated fluoroquinolone resistance genes from Escherichia coli isolates and their dissemination in Shandong, China.

Bacterial resistance to fluoroquinolones result from mutations in the quinolone resistance-determining regions of the drug targets, overexpression of efflux pumps, and/or the more recently identified plasmid-mediated low-level resistance mechanisms. We investigated the prevalence of and characterized plasmid-mediated fluoroquinolone resistance genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA) by polymerase chain reaction in fluoroquinolone-resistant Escherichia coli (n = 530) isolated from a chicken farm, a pig farm, and hospitalized patients in Shandong, China, in 2007. The aac(6')-Ib-cr gene was the most prevalent resistance gene that was detected in bacteria isolated from all sources. Next was the qnrS gene, which was predominantly present in isolates from the pig farm. Only eight (5.8%) isolates from hospital patients were found to possess the qepA gene, and these isolates were first reported in qepA-carrying E. coli from humans in China. The qnrA and qnrB genes were not detected in any of the isolates. Further, most of the isolates were also resistant to beta-lactams and aminoglycosides as determined by the broth microdilution method. Pulsed-field gel electrophoresis analysis of the E. coli isolates with similar resistance patterns that also carried resistance genes showed great genomic diversity among these bacteria, suggesting that the multiresistant E. coli isolates carrying the qnr, aac(6')-Ib-cr, or qepA genes were not derived from a specific clone, but represented a wide variety of different genotypes. The results of Southern hybridization revealed that qepA, qnrS, and parts of aac(6')-Ib-cr genes were localized on plasmids and/or chromosome. qepA and aac(6')-Ib-cr genes were colocalized with aac(6')-Ib-cr and qnrS genes, respectively, on the same plasmids. Our study demonstrated that two different genes (qepA and aac(6')-Ib-cr) were identified on the same plasmid in E. coli strains derived from patients and qnrS and aac(6')-lb-cr genes on the same plasmid in an E. coli strain of animal origin.

Characterization of antimicrobial resistance and integrons among Escherichia coli isolated from animal farms in Eastern China.

A total of 182 Escherichia coli isolates from animals, environment and workers of dairy cattle, swine and chicken farms in Shandong which locates in Eastern China, were investigated for antimicrobial resistance as well as prevalence and the transfer mechanisms of integrons. The results revealed isolates from swine and chicken farm exhibited high levels of resistance to antimicrobial agents. The positive rate of gene cassette of class 1 integron in dairy cattle, swine and chicken farms was 5%, 20% and 41.94%, respectively. Only four isolates possessed class 2 integron, all of which were from chicken farm. Nine distinct cassette arrays were detected and two novel gene cassette arrays yheSDelta-yheR-kefBDelta and chrADelta-sul1-qacEDelta1-orf5-aadA5-dfrA17 were identified in class 1 integron for the first time. Class 1 integrons were found to be located mostly in both chromosomal and conjugative plasmid through southern hybridization and conjugation. PFGE revealed clonal relatedness among the isolates from different sources, especially within the same farm. The results confirmed the antimicrobial resistance and prevalence of integrons were strongly associated with the selection pressure of antimicrobial agents, and resistance genes in animal farms were probably spread by both vertical and horizontal transfer.

Increased prevalence of plasmid-mediated quinolone resistance determinants in chicken Escherichia coli isolates from 2001 to 2007.

To evaluate the temporal change in the plasmid-mediated quinolone resistance (PMQR) determinants from 2001 to 2007 in chicken, a total of 532 chicken Escherichia coli isolates were screened for PMQR determinants by polymerase chain reaction and sequencing. The prevalence of qnr genes, aa(6')-Ib-cr, and qepA were 9.8%, 11.7%, and 0.75%, respectively. Among the qnr determinants, qnrA-, qnrB-, and qnrS-type genes were detected in 4 (0.75%), 21 (3.9%), and 27 (5.1%) of the examined isolates, respectively. None of the isolates carried qnrC gene. Ciprofloxacin resistance increased over time (p < 0.01), and a clear trend of increase in the prevalence of qnr and aac(6')-Ib-cr genes among the isolates was shown from 2001 to 2007 (p < 0.01). Pulsed-field gel analysis showed that the PMQR-positive isolates were not clonally related and genetically diverse. Quinolone resistance was transferred by conjugation from qnrB-, qnrS-, and aac(6')-Ib-cr-positive isolates to recipient E. coli. The qnrB and aac(6')-Ib-cr alleles were located on the plasmids with the size of 49 and 50 kb, respectively. However, the qnrS alleles were located on different plasmids with sizes from 57.4 to 88.6 kb, indicating diverse genetic backgrounds. The increasing frequency of ciprofloxacin resistance in E. coli was associated with increasing prevalence of qnr genes and aac(6')-Ib-cr (r(s) = 0.964, p = 0.00045). This survey showed that PMQR determinants were highly prevalent in chicken E. coli isolates in China with a trend of increase from 2001 to 2007. Horizontal transfer and widespread use of quinolone antimicrobials may have contributed to the spread of PMQR determinants in the poultry production system. The widespread dissemination of PMQR could potentially fuel the rapid development of fluoroquinolones resistance.

Selection of anti-sulfadimidine specific ScFvs from a hybridoma cell by eukaryotic ribosome display.

BACKGROUND: Ribosome display technology has provided an alternative platform technology for the development of novel low-cost antibody based on evaluating antibiotics derived residues in food matrixes. METHODOLOGY/PRINCIPAL FINDINGS: In our current studies, the single chain variable fragments (scFvs) were selected from hybridoma cell lines against sulfadimidine (SM(2)) by using a ribosome library technology. A DNA library of scFv antibody fragments was constructed for ribosome display, and then mRNA-ribosome-antibody (MRA) complexes were produced by a rabbit reticulocyte lysate system. The synthetic sulfadimidine-ovalbumin (SM(2)-OVA) was used as an antigen to pan MRA complexes and putative scFv-encoding genes were recovered by RT-PCR in situ following each panning. After four rounds of ribosome display, the expression vector pCANTAB5E containing the selected specific scFv DNA was constructed and transformed into Escherichia coli HB2151. Three positive clones (SAS14, SAS68 and SAS71) were screened from 100 clones and had higher antibody activity and specificity to SM(2) by indirect ELISA. The three specific soluble scFvs were identified to be the same molecular weight (approximately 30 kDa) by Western-blotting analysis using anti-E tag antibodies, but they had different amino acids sequence by sequence analysis. CONCLUSIONS/SIGNIFICANCE: The selection of anti-SM(2) specific scFv by in vitro ribosome display technology will have an important significance for the development of novel immunodetection strategies for residual veterinary drugs.

Distribution of superantigenic toxin genes in Staphylococcus aureus isolates from milk samples of bovine subclinical mastitis cases in two major diary production regions of China.

To evaluate the distribution of most known staphylococcal superantigen (SAg) genes in Staphylococcus aureus isolated from bovine mastitis cases, a genetic analysis of 15 SAg genes and genotypes was performed in a total of 283 S. aureus isolates collected from milk samples of cows with subclinical mastitis in two major diary production regions of China. Almost 65% of the isolates possessed at least one toxin gene. The most frequently found genes were sea (36.0%) followed by sei (31.8%), seg (31.4%) and selm (26.9%). The genes see, selk, or selo were not found in any of the isolates tested. Overall, 28 SAg genotypes were observed, among which the genotypes sea-seg-sei-selm, seg-sei-selm-seln, and sea-sed-selj predominated at the rate of 8.8%, 7.4%, and 6.7%, respectively. Marked geographical variations were noticed in the distribution of individual SAg genes and genotypes among S. aureus isolates from the two different regions. The relationship between toxin genotypes and toxin genes encoding profiles of mobile genetic elements (MGEs) was analyzed, revealing that majority of SAg genes were present in certain MGEs, which were in accordance with current knowledge about MGEs carrying those genes. However, some gene combinations suggest the possibility of the existence of variants or new types of MGEs.

[Analysis of 72 affective disorder cases in forensic psychiatric expertise].

OBJECTIVE: To explore criminal characteristics of patients with affective disorder. METHODS: Analysis was conducted in 72 cases of affective disorder diagnosed in Ankang Hospital, Public Security Bureau of Hangzhou, from 2000 to 2004. RESULTS: There was a correlation between outbreak of the affective disordered and frequency of committing crime. There was a significant difference between the mania and the depression (P<0.01) with respect to harmful behavior. The criminal behavior characteristics of patients with affective disorder were different from that of the schizophrenia, with more realistic and less pathologic intention. CONCLUSION: Recurrent attacks are warning signs for affective disorder patients committing crime. The criminal behavior characteristics of the affective disorder are different from that of the schizophrenia, probably because of the differences in etiological factor, development, symptom, and severity of the disorders.