Whole Genome Classification and Phylogenetic Analyses of Rotavirus B strains from the United States

Rotaviruses (RVs) are a major etiological agent of acute viral gastroenteritis in humans and young animals, with rotavirus B (RVB) often detected in suckling and weaned pigs. Group A rotavirus classification is currently based on the two outer capsid proteins, VP7 and VP4, and the middle layer protein, VP6. Using RVB strains generated in this study and reference sequences from GenBank, pairwise identity frequency graphs and phylogenetic trees were constructed for the eleven gene segments of RVB to estimate the nucleotide identity cutoff values for different genotypes and determine the genotype diversity per gene segment. Phylogenetic analysis of VP7, VP4, VP6, VP1–VP3, and NSP1–NSP5 identified 26G, 5P, 13I, 5R, 5C, 5M, 8A, 10N, 6T, 4E, and 7H genotypes, respectively. The analysis supports the previously proposed cutoff values for the VP7, VP6, NSP1, and NSP3 gene segments (80%, 81%, 76% and 78%, respectively) and suggests new cutoff values for the VP4, VP1, VP2, VP3, NSP2, NSP4, and NSP5 (80%, 78%, 79%, 77% 83%, 76%, and 79%, respectively). Reassortment events were detected between the porcine RVB strains from our study. This research describes the genome constellations for the complete genome of Group B rotaviruses in different host species.

A multiplex real-time PCR assay, based on invA and pagC genes, for the detection and quantification of Salmonella enterica from cattle lymph nodes

Cattle lymph nodes can harbor Salmonella and potentially contaminate beef products. We have developed and validated a new real-time PCR (qPCR) assay for the detection and quantification of Salmonella enterica in cattle lymph nodes. The assay targets both the invA and pagC genes, the most conserved molecular targets in Salmonella enterica. An 18S rRNA gene assay that amplifies from cattle and other animal species was also included as an internal control. Available DNA sequences for invA, pagC and 18S rRNA genes were used for primer and probe selections. Three Salmonella serotypes, S. Typhimurium, S. Anatum, and S. Montevideo, were used to assess the assay's analytical sensitivity. Correlation coefficients of standard curves generated for each target and for all three serotypes were >99% and qPCR amplification efficiencies were between 93% and 110%. Assay sensitivity was also determined using standard curve data generated from Salmonella-negative cattle lymph nodes spiked with 10-fold dilutions of the three Salmonella serotypes. Assay specificity was determined using Salmonella culture method, and qPCR testing on 36 Salmonella strains representing 33 serotypes, 38 Salmonella strains of unknown serotypes, 252 E. coli strains representing 40 serogroups, and 31 other bacterial strains representing 18 different species. A collection of 647 cattle lymph node samples from steers procured from the Midwest region of the US were tested by the qPCR, and compared to culture-method of detection. Salmonella prevalence by qPCR for pre-enriched and enriched lymph nodes was 19.8% (128/647) and 94.9% (614/647), respectively. A majority of qPCR positive pre-enriched samples (105/128) were at concentrations between 10⁴ and 10⁵ CFU/mL. Culture method detected Salmonella in 7.7% (50/647) and 80.7% (522/647) of pre- and post-enriched samples, respectively; 96.0% (48/50) of pre-enriched and 99.4% (519/522) of post-enriched culture-positive samples were also positive by qPCR. More samples tested positive by qPCR than by culture method, indicating that the real-time PCR assay was more sensitive. Our data indicate that this triplex qPCR can be used to accurately detect and quantify Salmonella enterica strains from cattle lymph node samples. The assay may serve as a useful tool to monitor the prevalence of Salmonella in beef production systems.

Insertion methods comparison for The Streamlined Liner of the Pharynx Airway in children by novice

BACKGROUND

The Streamlined Liner of the Pharynx Airway (SLIPA™) is a popular supraglottic airway device used for pediatric anesthesia. However, based on the anatomical features of pediatric patients, novice residents are expected to have difficulties inserting the device. The objective of this work was to improve the SLIPA insertion by modifying the device.

METHODS

A total of 134 children were randomized into two groups. Anesthesia was standardized among all patients except for the way in which the SLIPA was inserted. One group underwent the conventional method of insertion (Group C), while the modified group received a SLIPA that was bent120° at the 'bridge' point with an intubating stylet (Group M). The primary outcome was insertion success rate, and the secondary outcomes included insertion time, incidence of complications and hemodynamic responses to insertion.

RESULTS

The insertion success rate was significantly higher in Group M than Group C (94% vs. 73%, Χ² = 10.659, P = 0.001). The insertion time for Group M [29.31 (25.91-35.60) seconds] was shorter than for Group C [34.72 (26.81-42.58) seconds] (Z = -2.381, P = 0.017). Trends in heart rate (F = 0.260, P = 0.794), mean blood pressure (F = 0.167, P = 0.683) did not significantly differ between the two groups over time. In terms of complications, we found no significant differences between groups (P > 0.05).

CONCLUSION

The 120° bend improved SLIPA insertion when performed by novice, as reflected by higher insertion success rates and shorter insertion times, with no statistical differences in hemodynamic response to insertion or the incidence rates of complications between the two groups.

Genetic Analysis of Virulence Potential of Escherichia coli O104 Serotypes Isolated From Cattle Feces Using Whole Genome Sequencing

Escherichia coli O104:H4, a Shiga toxin-producing hybrid pathotype that was implicated in a major foodborne outbreak in Germany in 2011, has not been detected in cattle. However, serotypes of O104, other than O104:H4, have been isolated from cattle feces, with O104:H7 being the most predominant. In this study, we investigated, based on whole genome sequence analyses, the virulence potential of E. coli O104 strains isolated from cattle feces, since cattle are asymptomatic carriers of E. coli O104. The genomes of ten bovine E. coli O104 strains (six O104:H7, one O104:H8, one O104:H12, and two O104:H23) and five O104:H7 isolated from human clinical cases were sequenced. Of all the bovine O104 serotypes (H7, H8, H12, and H23) that were included in the study, only E. coli O104:H7 serotype possessed Shiga toxins. Four of the six bovine O104:H7 strains and one of the five human strains carried stx1c. Three human O104 strains carried stx2, two were of subtype 2a, and one was 2d. Genomes of stx carrying bovine O104:H7 strains were larger than the stx-negative strains of O104:H7 or other serotypes. The genome sizes were proportional to the number of genes carried on the mobile genetic elements (phages, prophages, transposable elements and plasmids). Both bovine and human strains were negative for intimin and other genes associated with the type III secretory system and non-LEE encoded effectors. Plasmid-encoded virulence genes (ehxA, epeA, espP, katP) were also present in bovine and human strains. All O104 strains were negative for antimicrobial resistance genes, except one human strain. Phylogenetic analysis indicated that bovine E. coli O104 strains carrying the same flagellar antigen clustered together and STEC strains clustered separately from non-STEC strains. One of the human O104:H7 strains was phylogenetically closely related to and belonged to the same sequence type (ST-1817) as the bovine O104:H7 STEC strains. This suggests that the bovine feces could be a source of human illness caused by E. coli O104:H7 serotype. Because bovine O104:H7 strains carried virulence genes similar to human clinical strains and one of the human clinical strains was phylogenetically related to bovine strains, the serotype has the potential to be a diarrheagenic pathogen in humans.

Simulation Evaluation of Cardiac Assist Devices

During past decades, various cardiac assist devices were invented. These cardiac assist devices can be classified into two categories: parallel connected or sequentially connected to the natural heart. In the past, more attention was paid to the assistance of the device provided to the failing heart and most research was conducted towards that goal. While less attention was paid to the “dose” of the assistance for rehabilitation of the natural heart. In our study, the hemodynamic effects of parallel as well as sequential cardiac assist devices are investigated in terms of the working load to the natural heart, and the oxygen supply and consumption of the natural heart. Preliminary results show that the sequential assistance could reduce the working load of the natural heart as well as increase the coronary flow. The results also indicate that the control scheme of the cardiac assist device has effect on the oxygen supply and consumption of the natural heart. There is optimal “dose” of assistance for the rehabilitation of the natural heart.

Comparative genomics reveals differences in mobile virulence genes of Escherichia coli O103 pathotypes of bovine fecal origin

Escherichia coli O103, harbored in the hindgut and shed in the feces of cattle, can be enterohemorrhagic (EHEC), enteropathogenic (EPEC), or putative non-pathotype. The genetic diversity particularly that of virulence gene profiles within O103 serogroup is likely to be broad, considering the wide range in severity of illness. However, virulence descriptions of the E. coli O103 strains isolated from cattle feces have been primarily limited to major genes, such as Shiga toxin and intimin genes. Less is known about the frequency at which other virulence genes exist or about genes associated with the mobile genetic elements of E. coli O103 pathotypes. Our objective was to utilize whole genome sequencing (WGS) to identify and compare major and putative virulence genes of EHEC O103 (positive for Shiga toxin gene, stx1, and intimin gene, eae; n = 43), EPEC O103 (negative for stx1 and positive for eae; n = 13) and putative non-pathotype O103 strains (negative for stx and eae; n = 13) isolated from cattle feces. Six strains of EHEC O103 from human clinical cases were also included. All bovine EHEC strains (43/43) and a majority of EPEC (12/13) and putative non-pathotype strains (12/13) were O103:H2 serotype. Both bovine and human EHEC strains had significantly larger average genome sizes (P < 0.0001) and were positive for a higher number of adherence and toxin-based virulence genes and genes on mobile elements (prophages, transposable elements, and plasmids) than EPEC or putative non-pathotype strains. The genome size of the three pathotypes positively correlated (R² = 0.7) with the number of genes carried on mobile genetic elements. Bovine strains clustered phylogenetically by pathotypes, which differed in several key virulence genes. The diversity of E. coli O103 pathotypes shed in cattle feces is likely reflective of the acquisition or loss of virulence genes carried on mobile genetic elements.

Ectopic Cartilage Formation Induced by Mesenchymal Stem Cells on Porous Gelatin-Chondroitin-Hyaluronate Scaffold Containing Microspheres Loaded with TGF-β1

The study aimed to produce a novel porous gelatin-chondroitin-hyaluronate scaffold in combination with a controlled release of TGF-β1 and to evaluate its potentials in ectopic cartilage formation. The gelatin-chondroitin-hyaluronate scaffold was developed to mimic the natural extra cellular matrix of cartilage. Gelatin microspheres loaded with TGF-β1 (MS-TGFβ1) showed a fast cytokine release at initial phase (37.4%) and the ultimate accumulated release was 83.1% by day 18. Then MS-TGFβ1 were incorporated into scaffold. The MSCs seeded on scaffold with or without MS-TGFβ1 were incubated in vitro or implanted subcutaneously in nude mice. In vitro study showed that, compared to the scaffold, the scaffold/MS-TGFβ1 significantly augmented the proliferation of MSCs and GAG synthesis. Three weeks postoperatively histology observation showed that in MSCs/scaffold/MS-TGFβ1 implantation group, cells of newly formed ectopic cartilage were located within typical lacunae and demonstrated morphological characteristics of chondrocytes. Six weeks later the ectopic cartilage grew more and islands of cartilage were observed. The matrix was extensively metachromatic by safranin-O/Fast green staining. Immunohistochemical staining also indicated ectopic cartilage was intensely stained for type II collagen. Instead, in the MSCs/scaffold implantation group, no cartilage-like tissue formed and matrix showed negative or weak positive staining. The percentage of positive staining area was significantly larger in MSCs/scaffold/MS-TGFβ1 group (p<0.05) at each time point. The results indicated that the novel gelatin-chondroitin-hyaluronate scaffold with MS-TGFβ1 could induce the chondral differentiation of MSCs to form cartilage and might serve as a new way to repair cartilage defects.

Molecular detection and characterization of transient bovine viral diarrhea virus (BVDV) infections in cattle commingled with ten BVDV persistently infected cattle

Fifty-three cattle of unknown serologic status that were not persistently infected (PI) with bovine viral diarrhea virus (BVDV) were commingled with 10 cattle that were PI with different strains of BVDV, and were monitored for an extended commingle period using a reverse-transcription real-time PCR (RT-rtPCR) BVDV assay on various sample types. Transient infections with BVDV were also assessed by virus isolation, virus neutralization (VN) assays, and direct buffy coat 5'-UTR sequencing. Infections were demonstrated in all cattle by RT-rtPCR; however, the detection rate was dependent on the type of sample. Buffy coat samples demonstrated a significantly greater number of positive results ( p ≤ 0.05) than either serum or nasal swab samples. Presence of elevated BVDV VN titers at the onset inversely correlated with the number of test days positive that an individual would be identified by RT-rtPCR from buffy coat samples, and directly correlated with the average Ct values accumulated over all RT-rtPCR test days from buffy coat samples. Both single and mixed genotype/subgenotype/strain infections were detected in individual cattle by direct sample 5'-UTR sequencing. A BVDV-2a strain from a PI animal was found to be the predominant strain infecting 64% of all non-PI cattle; BVDV-1b strains originating from 3 PI cattle were never detected in non-PI cattle. Although direct sample 5'-UTR sequencing was capable of demonstrating mixed BVDV infections, identifying all strains suspected was not always efficient or possible.

[Screening of Differential Expression Proteins in Rat Brain Tissues after DAI by iTRAQ-LC-MS/MS]

OBJECTIVES

To screen for the differential expression proteins in brain tissues of SD rat after diffuse axonal injury （DAI） by isobaric tag for relative and absolute quantification-liquid chromatograph-mass spectrometer/mass spectrometer （iTRAQ-LC-MS/MS）, and to explore potential biomarkers available for the diagnosis of DAI.

METHODS

Animal models of DAI were established with the Marmarou method as reference, and the subjects were divided into blank control group （n=4）, sham strike group （n=4） and fatal strike group （n=4）, respectively. The proteins in rat brain tissues were detected by iTRAQ-LC-MS/MS, and bioinformatics analysis and verification were performed on the results and screened for the differential expression proteins.

RESULTS

A total of 2 016 proteins were identified and quantified. The bioinformatics analysis revealed that the proteins had wide distribution and function, and participated in different biological processes. There were 16 proteins showed differential expression in fatal strike group, including one up-regulated expression protein and 15 down-regulated expression proteins. The results of iTRAQ-LC-MS/MS were confirmed by Western blotting method.

CONCLUSIONS

Multiple differential expression proteins in rat brain tissues after DAI can be screened by iTRAQ-LC-MS/MS. This not only indicates a research direction for exploring the pathogenesis of DAI, but also provides potential biomarkers available for the diagnosis of DAI.

[Overexpression of TRPV1 after periphery nerve injury attenuates nerve regeneration in rats]

Objective: To observe the effect of the expressive or functional blockage of TRPV1 on nerve regeneration after sciatic trans-section injury. Methods: AMG-517, a kind of TRPV1 inhibitor, was injected into the surrounding area of the ipsilateral lumbar dorsal root ganglia while unilateral sciatic nerve was transected. A total of 24 healthy male Sprague-Dawley rats were divided into 4 groups: control group, injury only group, injury+ AMG-517 150 μg/kg group, injury+ AMG-517 300 μg/kg group. The injury only group was injected the same volume of medium. The release of CGRP from dorsal-horn of spinal cord, the number of axons at proximal stem of sciatic nerve after transection, and the expression of TRPV1 in dorsal root ganglion were detected using the methods of ELISA, Western blot and semi-thin section (1 μm)- toluidine blue staining 2 weeks after injury. Results: The release of CGRP in lumbar spinal dorsal horn was obviously decreased after AMG-517 treatment, which was the evidence of TRPV1 functional inhibition. CGRP in the control group was 0.15 ng/g, the injury only group 0.17 ng/g, AMG-517 150 μg/kg group 0.09 ng/g, and AMG-517 300 μg/kg group 0.11 ng/g(P<0.01). The number of axons which were myelinated or unmyelinated increased after the TRPV1 was inhibited by AMG-517(P<0.01). In addition, the injection of AMG-517 into surrounding dorsal root ganglion decreased the expression of TRPV1 in dorsal root ganglion(P<0.01). Conclusions: Over expression or activation of TRPV1 after periphery nerve injury has negative effect on nerve regeneration in fact; Inhibiting the over-expression or over-activation of TRPV1 after nerve injury facilitates axonal regeneration and nerve repair.

[Changes of HbCO in the Blood of Rats with Different CO Concentration and Inhalation Time]

OBJECTIVES

To explore the change rules of behavioral characteristics, survival time and saturation of carboxyhemoglobin （HbCO） in different CO concentration to provide experimental basis for the cases of CO poisoning death in forensic practice.

METHODS

Total 160 SD rats were randomly divided into four groups. CO with the concentration of 1 250 mg/m³, 3 750 mg/m³, 6 250 mg/m³ were continuously and respectively replenished in a self-made toxicant exposure equipment until rats died from poisoning. In different CO concentration, the behavioral characteristics and survival time of poisoning rats were observed and recorded. The saturation of HbCO in heart blood was detected by spectrophotometric method. Organs such as brain, heart, lung and liver, and heart blood were obtained via autopsy and histopathological observation was performed.

RESULTS

The behavioral characteristics of CO poisoning rats were limp and slow response. There were a gradual decrease of survival time and an increase of HbCO saturation in rats with the increase of CO concentration. Three rats in CO concentration of 1 250 mg/m³ group showed lower saturations of HbCO than the lethal dose and this situation hasn't been found in other groups.

CONCLUSIONS

The animal model of CO poisoning established under different CO concentration has the advantages such as simplicity and good repeatability, which lays a foundation to the further study for CO and other inhaled toxic gas in the research of forensic sciences.

Characterizing the rapid spread of porcine epidemic diarrhea virus (PEDV) through an animal food manufacturing facility

New regulatory and consumer demands highlight the importance of animal feed as a part of our national food safety system. Porcine epidemic diarrhea virus (PEDV) is the first viral pathogen confirmed to be widely transmissible in animal food. Because the potential for viral contamination in animal food is not well characterized, the objectives of this study were to 1) observe the magnitude of virus contamination in an animal food manufacturing facility, and 2) investigate a proposed method, feed sequencing, to decrease virus decontamination on animal food-contact surfaces. A U.S. virulent PEDV isolate was used to inoculate 50 kg swine feed, which was mixed, conveyed, and discharged into bags using pilot-scale feed manufacturing equipment. Surfaces were swabbed and analyzed for the presence of PEDV RNA by quantitative real-time polymerase chain reaction (qPCR). Environmental swabs indicated complete contamination of animal food-contact surfaces (0/40 vs. 48/48, positive baseline samples/total baseline samples, positive subsequent samples/total subsequent samples, respectively; P < 0.05) and near complete contamination of non-animal food-contact surfaces (0/24 vs. 16/18, positive baseline samples/total baseline samples, positive subsequent samples/total subsequent samples, respectively; P < 0.05). Flushing animal food-contact surfaces with low-risk feed is commonly used to reduce cross-contamination in animal feed manufacturing. Thus, four subsequent 50 kg batches of virus-free swine feed were manufactured using the same system to test its impact on decontaminating animal food-contact surfaces. Even after 4 subsequent sequences, animal food-contact surfaces retained viral RNA (28/33 positive samples/total samples), with conveying system being more contaminated than the mixer. A bioassay to test infectivity of dust from animal food-contact surfaces failed to produce infectivity. This study demonstrates the potential widespread viral contamination of surfaces in an animal food manufacturing facility and the difficulty of removing contamination using conventional feed sequencing, which underscores the importance for preventing viruses from entering and contaminating such facilities.

[Clinical effect of vacuum sealing drainage in the treatment of complex fracture and dislocation of foot with severe soft tissue injury]

Objective: To observe the clinical effect of vacuum sealing drainage (VSD) in the treatment of complex fracture and dislocation of foot with severe soft tissue injury. Methods: From March 2012 to January 2015, a retrospective analysis of 108 cases of the foot closed complex fracture dislocation with severe soft tissue injury in Department of Foot and Ankle, the Second Hospital of Tangshan City, Tangshan.Injury mechanisms included press and crush injury, traffic accident.According to the operation the cases were divided into the VSD group (56 cases) and the control group (52 cases). The injury foot swelling after treated by open reduction and internal fixation or fusion joint fracture and dislocation. VSD technique was used to cover the wound and wound in group VSD. The wound was sutured, the sterile dressing was covered and the dressing was changed regularly in the control group. Results: Preoperative hospitalization time: 16 days in group VSD, 28 days in the control group; the total hospitalization time: 33 days in group VSD, 53 days in the control group; wound healing: 29 cases in VSD group, 12 cases in the control group; prolonged healing after dressing: 16 cases in VSD group, 13 cases in the control group; after skin grafting healing: 9 cases in VSD group, 17 cases in the control group; healed after flap transposition: 2 cases in VSD group and 10 cases in thecontrol group.The difference of the data of the two groups was statistically significant, P<0.05.Maryland foot score: 55-98 (average: 88.8, median: 91.5) points in VSD group, 38-97 (average: 84.85, median: 91) points in control group, compared with median by rank sum test, Z value: -2.755, the difference was statistically significant, P< 0.05.The late recovery effect rating: 39 casesexcellent, good 12 cases, can be 5 cases, no poor in VSD group, excellent 29 cases, good 8 cases, can be 11 cases, poor 4 cases in the the control group, the difference was statistically significant, P<0.05. Conclusion: VSD can shorten the preoperative waiting time and total hospitalization time, improve the wound healing rate directly, reduce the skin grafting and flap transfer replacement rate, reduce the secondary injury, increased fracture risk reduction and internal fixation, reduce joint fusion rate in the treatment of foot closed complex fracture and dislocation with severe soft tissue injury.

Effect of Shenqin biochemical extract on hypoxia-inducible factor-1α expression in ultraviolet B-irradiated HaCaT cells

Hypoxia-inducible factor-1α (HIF-1α) is considered the main transcriptional regulator of the hypoxia-specific cellular and developmental response. This study was performed to investigate the effect of Shenqin biochemical extract (SQBE) on HIF-1α expression in ultraviolet B (UVB)-irradiated HaCaT cells and the possible action mechanisms of SQBE against UVB-induced skin cancer. HaCaT cells in logarithmic growth phase were seeded in Dulbecco's modified Eagle's medium with 10% fetal bovine serum, and conventionally cultured at 37°C with 5% CO₂. Cells were divided into control group (administered the same amounts of dimethyl sulfoxide), SQBE1 group (12.5 μg/mL SQBE), SQBE2 group (25.0 μg/mL SQBE), and SQBE3 group (50.0 μg/mL SQBE). Four hours post administration, the control and treatment groups were irradiated with UVB (0, 20, 40, and 60 mJ/cm²). After 24 h, cell survival rate was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Expression levels of HIF-1α mRNA and protein were detected by polymerase chain reaction and western blotting, respectively. SQBE-treated, UVB-irradiated cells had improved survival rates. This increase was most significant in SQBE3 group (P < 0.01), which also had effectively reduced expression of intracellular HIF-1α mRNA and protein. Hence, SQBE had a protective effect on UVB-irradiated HaCaT cells and inhibited the UVB irradiation-induced expression of HIF-1α. This indicates that SQBE could prevent the occurrence of UVB radiation-induced skin cancer.

Spiral Plating Method To Quantify the Six Major Non-O157 Escherichia coli Serogroups in Cattle Feces

Cattle are a major reservoir of the six major Shiga toxin-producing non-O157 Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) responsible for foodborne illnesses in humans. Besides prevalence in feces, the concentrations of STEC in cattle feces play a major role in their transmission dynamics. A subset of cattle, referred to as super shedders, shed E. coli O157 at high concentrations (≥4 log CFU/g of feces). It is not known whether a similar pattern of fecal shedding exists for non-O157. Our objectives were to initially validate the spiral plating method to quantify the six non-O157 E. coli serogroups with pure cultures and culture-spiked fecal samples and then determine the applicability of the method and compare it with multiplex quantitative PCR (mqPCR) assays for the quantification of the six non-O157 E. coli serogroups in cattle fecal samples collected from commercial feedlots. Quantification limits of the spiral plating method were 3 log, 3 to 4 log, and 3 to 5 log CFU/mL or CFU/g for individual cultures, pooled pure cultures, and cattle fecal samples spiked with pooled pure cultures, respectively. Of the 1,152 cattle fecal samples tested from eight commercial feedlots, 122 (10.6%) and 320 (27.8%) harbored concentrations ≥4 log CFU/g of one or more of the six serogroups of non-O157 by spiral plating and mqPCR methods, respectively. A majority of quantifiable samples, detected by either spiral plating (135 of 137, 98.5%) or mqPCR (239 of 320, 74.7%), were shedding only one serogroup. Only one of the quantifiable samples was positive for a serogroup carrying Shiga toxin (stx1) and intimin (eae) genes; 38 samples were positive for serogroups carrying the intimin gene. In conclusion, the spiral plating method can be used to quantify non-O157 serogroups in cattle feces, and our study identified a subset of cattle that was super shedders of non-O157 E. coli. The method has the advantage of quantifying non-O157 STEC, unlike mqPCR that quantifies serogroups only.

Shiga Toxin Subtypes of Non-O157 Escherichia coli Serogroups Isolated from Cattle Feces

Shiga toxin producing Escherichia coli (STEC) are important foodborne pathogens responsible for human illnesses. Cattle are a major reservoir that harbor the organism in the hindgut and shed in the feces. Shiga toxins (Stx) are the primary virulence factors associated with STEC illnesses. The two antigenically distinct Stx types, Stx1 and Stx2, encoded by stx1 and stx2 genes, share approximately 56% amino acid sequence identity. Genetic variants exist within Stx1 and Stx2 based on differences in amino acid composition and in cytotoxicity. The objective of our study was to identify the stx subtypes in strains of STEC serogroups, other than O157, isolated from cattle feces. Shiga toxin gene carrying E. coli strains (n = 192), spanning 27 serogroups originating from cattle (n = 170) and human (n = 22) sources, were utilized in the study. Shiga toxin genes were amplified by PCR, sequenced, and nucleotide sequences were translated into amino acid sequences using CLC main workbench software. Shiga toxin subtypes were identified based on the amino acid motifs that define each subtype. Shiga toxin genotypes were also identified at the nucleotide level by in silico restriction fragment length polymorphism (RFLP). Of the total 192 STEC strains, 93 (48.4%) were positive for stx1 only, 43 (22.4%) for stx2 only, and 56 (29.2%) for both stx1 and stx2. Among the 149 strains positive for stx1, 132 (88.6%) were stx1a and 17 (11.4%) were stx1c. Shiga toxin 1a was the most common subtype of stx1 among cattle (87.9%; 123/140) and human strains (100%; 9/9) of non-O157 serogroups. Of the total 99 strains positive for stx2, 79 were stx2a (79.8%), 11 (11.1%) were stx2c, 12 (12.1%) were stx2d. Of the 170 strains originating from cattle feces, 58 (34.1%) were stx2a subtype, 11 (6.5%) were stx2c subtype, and 11 were of subtype stx2d (6.5%). All but one of the human strains were positive for stx2a. Three strains of cattle origin were positive for both stx2a and stx2d. In conclusion, a number of non-O157 STEC serogroups harbored by cattle possess a wide variety of Shiga toxin subtypes, with stx1a and stx2a being the most predominant stx subtypes occurring individually or in combination. Cattle are a reservoir of a number of non-O157 STEC serogroups and information on the Shiga toxin subtypes is useful in assessing the potential risk as human pathogens.

Experimental infection of conventional nursing pigs and their dams with Porcine deltacoronavirus

Porcine deltacoronavirus (PDCoV) is a newly identified virus that has been detected in swine herds of North America associated with enteric disease. The aim of this study was to demonstrate the pathogenicity, course of infection, virus kinetics, and aerosol transmission of PDCoV using 87 conventional piglets and their 9 dams, including aerosol and contact controls to emulate field conditions. Piglets 2-4 days of age and their dams were administered an oronasal PDCoV inoculum with a quantitative real-time reverse transcription (qRT)-PCR quantification cycle (Cq) value of 22 that was generated from a field sample having 100% nucleotide identity to USA/Illinois121/2014 determined by metagenomic sequencing and testing negative for other enteric disease agents using standard assays. Serial samples of blood, serum, oral fluids, nasal and fecal swabs, and tissues from sequential autopsy, conducted daily on days 1-8 and regular intervals thereafter, were collected throughout the 42-day study for qRT-PCR, histopathology, and immunohistochemistry. Diarrhea developed in all inoculated and contact control pigs, including dams, by 2 days post-inoculation (dpi) and in aerosol control pigs and dams by 3-4 dpi, with resolution occurring by 12 dpi. Mild to severe atrophic enteritis with PDCoV antigen staining was observed in the small intestine of affected piglets from 2 to 8 dpi. Mesenteric lymph node and small intestine were the primary sites of antigen detection by immunohistochemistry, and virus RNA was detected in these tissues to the end of the study. Virus RNA was detectable in piglet fecal swabs to 21 dpi, and dams to 14-35 dpi.

[The value of different antibodies detection in diagnosis of rheumatism with uveitis]

Objective: To investigate the value of HLA-B27 antigen, antinuclear antibody (ANA), anti-dsDNA and Anti-Neutrophil Cytoplasmic Antibodies (ANCA) detection in diagnosis of rheumatism with uveitis. Methods: Seven hundred and twenty four newly diagnosed patients with non-infection uveitis in Beijing Tongren Hospital from March 2012 to March 2016 who long-term lived in Beijing and its surrounding areas were continuously enrolled. HLA-B27 antigen expressions in peripheral blood lymphocytes and ANA, anti-dsDNA and ANCA levels in serum were tested. The detailed clinical data, imaging examinations and pathological examinations were recorded to define whether the patients had rheumatism and the types of rheumatism. Results: There were 285 patients were diagnosed with rheumatism in 724 patients (39.4%), with 135 male (47.4%) and 150 female (52.6%). The mean age of male (41±14) was lower than that of female (44±14), with statistically significant (t=2.18, P<0.05). There were 176 patients with Spondyloarthropathies, 48 patients with primary systemic vasculitis, 22 patients with systemic lupus erythematosus, 18 patients with primary Sjogren's syndrome, 16 patients with rheumatoid arthritis and 5 patients with juvenile idiopathic arthritis in 285 rheumatism patients. The positive rate of HLA-B27(57.2%), ANA(15.8%), anti-dsDNA (5.3%) and ANCA(9.1%) in rheumatic uveitis patients were obviously higher than those of non-rheumatic uveitis patients [HLA-B27(1.1%), ANA(1.6%), anti-dsDNA (0.0%) and ANCA(0.9%)], with statistically significant (Fisher's exact test, P<0.01). The HLA-B27 positive antigen were mainly in patients with Spondyloarthropathies, rate was 92.1%; the positive ANA were mainly in patients with systemic lupus erythematosus, rate was 95.5%; the positive anti-dsDNA were mainly in patients with systemic lupus erythematosus, rate was 59.1%; the positive ANCA were mainly in patients with primary systemic vasculitis (besides Behcet disease), rate was 57.1%. Conclusions: The detections of HLA-B27 antigen, ANA, anti-dsDNA and ANCA are valuable for primary screening of some rheumatic uveitis. There fore, clinicians should select targeted laboratory examination combine with the patients' clinical manifestations. This will be helpful in the auxiliary diagnosis of some types of rheumatic uveitis.

[Clinical effect of double layer vacuum sealing drainage in the treatment of delayed severe infection after calcaneal fracture operation]

Objective: To observe the clinical effect of vacuum sealing drainage (VSD) technique and simple dressing change in the treatment of delayed severe infection after calcaneal fracture surgery. Methods: From August 2008 to July 2015 , 73 patients with delayed severe infection were treated after calcaneal fractures 3 months in Department of Foot and Ankle, the Second Hospital of Tangshan City, according to the treatment methods are divided into vacuum sealing drainage group of 38 cases, 35 cases of simple dressing group.Two groups of patients after regular wound debridement debridement and sterilization after vacuum sealing drainage group received double wound VSD dressing group received postoperative dressing, two groups of patients with sensitive antibiotics for treatment.Two groups of patients according to the frequency of dressing change, wound healing time, bacterial clearance time and healing time were compared in stage Ⅱ during the perioperative period. Results: Vacuum sealing drainage group: dressing: 7 times, the wound healing time was 27 days, bacterial culture negative for 8 days, the healing time of 13.5 days of perioperative period; treatment group: 34 times the number of dressing, wound healing time was 44 days, bacterial culture negative for 18 days, the healing time of 17 days of surgery period. Two groups of data were compared with the median, after the rank sum test, the difference was statistically significant (Z values were -6.670, -5.529, -5.011, -3.227, P<0.05). The vacuum sealing drainage group compared with conventional dressing group significantly reduced the number of dressing, wound healing time, healing time was significantly shortened bacterial clearance time and perioperative period Ⅱ. Conclusion: Double VSD is easy , safe and quick, short cure time, less pain, higher quality of late life advantages, compared with the traditional dressing treatment of calcaneal fractures of postoperative delayed severe infection, is a safe and effective method.