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Bacterial resistance to antibiotics has become an important concern for public health. This study was aimed to investigate the characteristics and the distribution of the florfenicol-related resistance genes in bacteria isolated from four farms. A total of 106 florfenicol-resistant Gram-negative bacilli were examined for florfenicol-related resistance genes, and the positive isolates were further characterized. The antimicrobial sensitivity results showed that most of them (100, 94.33%) belonged to multidrug resistance Enterobacteriaceae . About 91.51% of the strains carried floR gene, while 4.72% carried cfr gene. According to the pulsed-field gel electrophoresis results, 34 Escherichia coli were subdivided into 22 profiles, the genetic similarity coefficient of which ranged from 80.3 to 98.0%. The multilocus sequence typing (MLST) results revealed 17 sequence types (STs), with ST10 being the most prevalent. The genome sequencing result showed that the Proteus vulgaris G32 genome consists of a 4.06-Mb chromosome, a 177,911-bp plasmid (pG32-177), and a 51,686-bp plasmid (pG32-51). A floR located in a drug-resistant region on the chromosome of P. vulgaris G32 was with IS 91 family transposase, and the other floR gene on the plasmid pG32-177 was with an IS CR2 insertion sequence. The cfr gene was located on the pG32-51 flanked by IS 26 element and TnpA26. This study suggested that the mobile genetic elements played an important role in the replication of resistance genes and the horizontal resistance gene transfer., (Copyright © 2020 Li, Zhu, Zhou, Lu, Liu, Sun, Ying, Lu, Lin, Li, Ying, Bao and Xu.)

Background: The main treatment of choledochal cysts is the complete resection of the cyst with Roux-en-Y hepaticojejunostomy, which includes open procedures, laparoscopic procedures, and robot-assisted procedures using a da Vinci surgical system. The aim of this current study was to investigate the safety and effectiveness of these three different surgical methods in pediatric choledochal cyst excisions., Methods: Between January 2015 and December 2018, patients with choledochal cysts treated with open procedures, laparoscopic procedures, or robot-assisted procedures were retrospectively analyzed. The data collected included demographic information of all patients, type and size of cyst, operative details, and postoperative outcomes., Results: A total of 371 episodes of patients were enrolled which consist of the open procedures group (n = 226), laparoscopic procedures group (n = 104), and robot-assisted procedures group (n = 41). The operation time was significantly longer in the laparoscopic procedures group (212.79 ± 34.94) than open procedures group (115.88 ± 13.50) and robot-assisted procedures group (180.61 ± 14.07) (p < 0.001). The volume of intraoperative bleeding were higher in the open procedures group (40.12 ± 55.51) than in the laparoscopic procedures group (21.73 ± 11.44) and robot-assisted procedures group (21.34 ± 9.42), while there was no significant difference between the latter groups. The time to taking water, time to starting liquid diet, and the average length of postoperative hospital stay were similar between the laparoscopic and robot-assisted procedures group, which are shorter than the open procedures group with significant differences. There was no signifcant difference in complications among the three groups., Conclusion: Choledochal cyst excision with robotic-assisted procedures had identical surgical effects as open procedures and had lower technical requirements. But it had higher medical cost and better cosmetic effects. Open procedures had largely positive surgical outcomes with fewest complications but poor cosmetic effects. Laparoscopic procedures were the most technique-demanding approaches with positive cosmetic and economic effect. The incidence of complications of laparoscopic procedures decreased with the learning curve.

Staphylococcus caprae, Staphylococcus capitis , and Staphylococcus epidermidis belong to the "Epidermidis Cluster Group" (ECG) and are generally opportunistic pathogens. In this work, whole genome sequencing, molecular cloning and pan-genome analysis were performed to investigate the genetic characteristics of the resistance, virulence and genome structures of 69 ECG strains, including a clinical isolate ( S. caprae SY333) obtained in this work. Two resistance genes ( blaZ and aadD2 ) encoded on the plasmids pSY333-41 and pSY333-45 of S. caprae SY333 were confirmed to be functional. The bla region in ECG exhibited three distinct structures, and these chromosome- and plasmid-encoded bla operons seemed to follow two different evolutionary paths. Pan-genome analysis revealed their pan-genomes tend to be "open." For the virulence-related factors, the genes involved in primary attachment were observed almost exclusively in S. epidermidis , while the genes associated with intercellular aggregation were observed more frequently in S. caprae and S. capitis . The type VII secretion system was present in all strains of S. caprae and some of S. epidermidis but not in S. capitis . Moreover, the isd locus (iron regulated surface determinant) was first found to be encoded on the genomes of S. caprae and S. capitis . These findings suggested that the plasmid and chromosome encoded bla operons of ECG species underwent different evolution paths, as well as they differed in the abundance of virulence genes associated with adherence, invasion, secretion system and immune evasion. Identification of isd loci in S. caprae and S. capitis indicated their ability to acquire heme as nutrient iron during infection., (Copyright © 2020 Sun, Zhou, Zhang, Li, Lin, Lu, Liu, Lu, Lin, Li, Xu, Bao and Zhang.)

Background: Endoscopic retrograde biliary drainage (ERBD) is the most frequently performed procedure for treating benign or malignant biliary obstruction. Although duodenal perforations secondary to the biliary plastic stent are quite rare, they can be life-threatening. The treatment strategies for such perforations are diverse and continue to be debated., Case Presentation: We report three cases of duodenal perforation due to the migration of biliary plastic stents that were successfully managed using an endoscope. The three patients were admitted on complaints of abdominal pain after they underwent ERBD. Abdominal computerized tomography (CT) revealed migration of the biliary plastic stents and perforation of the duodenum. Endoscopy was immediately performed, and perforation was confirmed. All migrated stents were successfully extracted endoscopically by using snares. In two of the three cases, the duodenal defects were successfully closed with haemostatic clips after stent retrieval, and subsequently, endoscopic nasobiliary drainage tubes were inserted. After the endoscopy and medical treatment, all three patients recovered completely., Conclusions: Duodenal perforations due to the migration of biliary stents are rare, and the treatment strategies remain controversial. Our cases and cases in the literature demonstrate that abdominal CT is the preferred method of examination for such perforations, and endoscopic management is appropriate as a first-line treatment approach.

Objectives: To evaluate the efficacy of different ways of cocktail analgesic mixture injection on total knee arthroplasty (TKA)., Methods: A total of 50 patients with knee osteoarthritis treated by TKA from July to September 2018 were randomly divided into two groups ( n =25). The Group 1 underwent anterior intra-articular injection before prosthesis implanted while the Group 2 underwent posterior intra-articular injection before prosthesis implanted. Visual Analogue Scale (VAS) of all patients for pain during activity and at rest, maximal flexion degree of the knee at the 48th h and the 72th h after surgery, the time of raise leg, usage rate of patient-controlled analgesia (PCA), and complications were evaluated and analyzed., Results: VAS for pain at rest of patients in the Group 1 was significantly less than that in the Group 2 at the 6th, 12th, and 24th h after surgery (all P <0.05). Maximal flexion degree of the knee at the 48th h and the 72th h after surgery in the Group 1 was better than that in the Group 2 (both P <0.05). The Group 1 costed less time than the Group 2 on the ability to perform an active straight leg raise ( P =0.027)., Conclusions: The anterior intra-articular cocktail analgesic mixture injection can strongly relieve the pain early after TKA, which can improve knee function and achieve painless rehabilitation in most patients, with safety.

The rate of brucellosis, a zoonotic disease, has rapidly increased in humans brucellosis(HB) in recent years. In 1950-2018, a total of 684,380 HB cases (median 2274/year (interquartile range (IQR) 966-8325)) were reported to the National Infectious Disease Surveillance System in mainland China. The incidence of HB peaked in 2014 (4.32/100,000), and then showed a downward trend; we predict that it will maintain a steady downward trend in 2019-2020. Since 2015, the incidence of HB has shown opposite trends in the north and south of China; rates in the north have fallen and rates in the south have increased. In 2004-2018, the most significant increases in incidence of HB were in Yunnan (IQR 0.002-0.463/100,000), Hubei (IQR 0.000-0.338/100,000), and Guangdong (IQR 0.015-0.350/100,000). The areas where HB occurs have little overlap with areas with high per capita GDP in China. The "high-high" clusters of HB are located in northeastern China (Inner Mongolia, Heilongjiang, Jilin, Liaoning, Ningxia, Shanxi, and Gansu), and the "low-low" clusters of HB are located in southern China (Yunnan, Jiangxi, Shanghai, Guangxi, Guangdong, Zhejiang, Guizhou, and Hunan). In recent years, the incidence of HB in China has been controlled to some extent, but the incidence of HB has increased in southern China, and the disease has spread geographically in China from north to south. Further research is needed to address this change and to continue to explore the relationship between the incidence of HB and relevant factors.

Cholestasis is common in multiple clinical circumstances. The NOD-like receptor protein 3 (NLRP3) inflammasome pathway has been demonstrated to play an important role in liver injury and fibrosis induced by cholestasis. We previously proved that MCC950, a selective NLRP3 inhibitor, alleviates liver fibrosis and injury in experimental liver cholestasis induced by bile-duct ligation (BDL) in mice. Herein, we investigate the role of calcipotriol, a potent vitamin D receptor agonist, in experimental liver cholestasis, test its therapeutic efficacy, and explore its potential protective mechanism. C57BL/6 mice were made to undergo BDL or fed the 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet to establish two classic cholestatic models. Calcipotriol was administered intraperitoneally to these mice daily. Serum makers of liver damage and integrity, liver histological changes, levels of liver pro-fibrotic markers, bile acid synthetases and transporters were measured in vivo . The underlying mechanism by which calcipotriol alleviates cholestatic liver injury and fibrosis was further investigated. The results of the current study demonstrated that calcipotriol supplement significantly alleviate cholestatic liver injury and fibrosis. Moreover, calcipotriol supplement markedly inhibited NLRP3 inflammasome pathway activation to alleviate liver injury and fibrosis in vivo and inhibit hepatic stellate cell (HSC) activation in vitro . In addition, VDR agonist calcipotriol exert inhibitory effect on NLRP3 inflammasome activation through activating yes-associated protein 1 (YAP1). In conclusion, our findings proved that calcipotriol suppressed the NLRP3 signal by activating YAP1 to alleviate liver injury and retard fibrogenesis in cholestasis., (Copyright © 2020 Wang, Wang, Qu, Yuan, Pan and Li.)

Airway infections associated with cystic fibrosis (CF) are polymicrobial. We reported previously that clinical isolates of Pseudomonas aeruginosa promote the growth of a variety of streptococcal species. To explore the mechanistic basis of this interaction, we performed a genetic screen to identify mutants of Streptococcus sanginuis SK36 whose growth was no longer enhanced by P. aeruginosa PAO1. Mutations in the zinc uptake systems of S. sanguinis SK36 reduced growth of these strains by 1 to 3 logs compared to that of wild-type S. sanguinis SK36 when grown in coculture with P. aeruginosa PAO1, and exogenous zinc (0.1 to 10 μM) rescued the coculture defect of zinc uptake mutants of S. sanguinis SK36. Zinc uptake mutants of S. sanguinis SK36 had no obvious growth defect in monoculture. Consistent with competition for zinc driving coculture dynamics, S. sanguinis SK36 grown in coculture with P. aeruginosa showed increased expression of zinc uptake genes compared to that of S. sanguinis grown alone. Strains of P. aeruginosa PAO1 defective in zinc transport also supported ∼2-fold more growth by S. sanguinis compared to that in coculture with wild-type P. aeruginosa PAO1. An analysis of 118 CF sputum samples revealed that total zinc levels varied from ∼5 to 145 μM. At relatively low zinc levels, Pseudomonas and Streptococcus spp. were found in approximately equal abundance; at higher zinc levels, we observed a decline in relative abundance of Streptococcus spp., perhaps as a result of increasing zinc toxicity. Together, our data indicate that the relative abundances of these microbes in the CF airway may be impacted by zinc levels. IMPORTANCE Polymicrobial infections in CF cases likely impact patient health, but the mechanism(s) underlying such interactions is poorly understood. Here, we show using an in vitro model system that interactions between Pseudomonas and Streptococcus are modulated by zinc availability, and clinical data are consistent with this model. Together with previous studies, our work supports a role for metal homeostasis as a key factor driving microbial interactions., (Copyright © 2020 American Society for Microbiology.)

Purpose: The aim of this work was to identify a novel β-lactamase gene bla PAU-1 encoded on the plasmid of a clinical Pseudomonas a er u ginosa isolate., Materials and Methods: The clinical P. aeruginosa isolates were isolated from a hospital in southern China. Molecular cloning was performed to analyze the function of the resistance gene. The minimum inhibitory concentration (MIC) was determined by means of the agar dilution method to determine the antimicrobial susceptibilities of the strains. Whole-genome sequencing and comparative genomics analysis were performed to analyze the structures of the resistance gene-related sequences., Results: PAU-1 is a molecular class A, Bush-Jacoby group 2be enzyme which encoded 293 amino acids and shared 74% amino acid identity with a putative class A β-lactamase from Rhodoferax saidenbachensis . Cloned bla PAU-1 in Escherichia coli and P. aeruginosa conferred resistance to piperacillin and ampicillin, and elevated the MIC with a 2-3 dilution for some oxyimino-β-lactams in P. aeruginosa . The genetic environment of bla PAU-1 is tnp A- res-hp-relE-bla PAU-1 - lysR , which is in accordance with the structure of a Tn 3 transposon. Epidemiological investigation of bla PAU-1 in the same district did not show any evidences of molecular dissemination associated with this determinant., Conclusion: A novel class A β-lactamase gene, bla PAU-1 , associated with the mobile genetic element was identified on a transferable plasmid in a clinical P. aeruginosa isolate. Strict surveillance for the emergence of the new determinant should be established and an effort should be made to block the dissemination of this determinant., Competing Interests: The authors report no conflicts of interest in this work., (© 2019 Wang et al.)

The diversity of class D β-lactamases mediating resistance to β-lactams has been increasingly reported recently. In this study, a novel class D oxacillinase named OXA-830 was identified in a fully sequenced Aeromonas simiae strain, which was isolated from sewage discharged from a farm in southern China. OXA-830 shares the highest amino acid identity of 79.3% with an OXA-12-like variant named OXA-725. When expressed in E. coli DH5α, OXA-830 conferred resistance to penicillins and selected β-lactamase inhibitors but not to cephalosporins and carbapenems. Kinetic analysis of OXA-830 revealed a broad substrate profile including penicillins, cefazolin, cefoxitin, and ceftazidime but not carbapenems. The hydrolytic activity was significantly inhibited by sulbactam, followed by tazobactam, but was less effectively inhibited by clavulanic acid. The bla OXA- 830 gene was located on the A. simiae A6 chromosome and the bla OXA- 830 -related region was bracketed by a pair of perfect inverted repeats., (Copyright © 2019 Chen, Zhou, Qian, Shen, Zhu, Zhou, Sun, Lu, Liu, Li, Xu, Bao and Lu.)

Swarming is a surface-associated motile behavior that plays an important role in the rapid spread, colonization, and subsequent establishment of bacterial communities. In Pseudomonas aeruginosa , swarming is dependent upon a functional flagella and aided by the production of biosurfactants. AmrZ, a conserved transcription factor across pseudomonads, has been shown to be a global regulator of multiple genes important for virulence and ecological fitness. In this study, we expand this concept of global control to swarming motility by showing that deletion of amrZ results in a severe defect in swarming, while multicopy expression of this gene stimulates swarming of P. aeruginosa . Mechanistic studies showed that the swarming defect of an amrZ mutant does not involve changes of biosurfactant production but is associated with flagellar malfunction. The ∆ amrZ mutant exhibits increased levels of the second messenger cyclic di-GMP (c-di-GMP) compared to the wild-type strain, under swarming conditions. We found that the diguanylate cyclase GcbA was the main contributor to the increased accumulation of c-di-GMP observed in the ∆ amrZ mutant and was a strong inhibitor of flagellar-dependent motility. Our results revealed that the GcbA-dependent inhibition of motility required the presence of two c-di-GMP receptors containing a PilZ domain: FlgZ and PA14&#95;56180. Furthermore, the ∆ amrZ mutant exhibits enhanced production of Pel polysaccharide. Epistasis analysis revealed that GcbA and the Pel polysaccharide act independently to limit swarming in Δ amrZ . Our results support a role for AmrZ in controlling swarming motility, yet another social behavior besides biofilm formation that is crucial for the ability of P. aeruginosa to colonize a variety of surfaces. The central role of AmrZ in controlling these behaviors makes it a good target for the development of treatments directed to combat P. aeruginosa infections.

Previous work from our group indicated an association between the gastrointestinal microbiota of infants with cystic fibrosis (CF) and airway disease in this population. Here we report that stool microbiota of infants with CF demonstrates an altered but largely unchanging within-individual bacterial diversity (alpha diversity) over the first year of life, in contrast to the infants without CF (control cohort), which showed the expected increase in alpha diversity over the first year. The beta diversity, or between-sample diversity, of these two cohorts was significantly different over the first year of life and was statistically significantly associated with airway exacerbations, confirming our earlier findings. Compared with control infants, infants with CF had reduced levels of Bacteroides , a bacterial genus associated with immune modulation, as early as 6 weeks of life, and this significant reduction of Bacteroides spp. in the cohort with CF persisted over the entire first year of life. Only two other genera were significantly different across the first year of life: Roseburia was significantly reduced and Veillonella was significantly increased. Other genera showed differences between the two cohorts but only at selected time points. In vitro studies demonstrated that exposure of the apical face of polarized intestinal cell lines to Bacteroides species supernatants significantly reduced production of interleukin 8 (IL-8), suggesting a mechanism whereby changes in the intestinal microbiota could impact inflammation in CF. This work further establishes an association between gastrointestinal microbiota, inflammation, and airway disease in infants with CF and presents a potential opportunity for therapeutic interventions beginning in early life. IMPORTANCE There is growing evidence for a link between gastrointestinal bacterial communities and airway disease progression in CF. We demonstrate that infants with CF ≤1 year of age show a distinct stool microbiota versus that of control infants of a comparable age. We detected associations between the gut microbiome and airway exacerbation events in the cohort of infants with CF, and in vitro studies provided one possible mechanism for this observation. These data clarify that current therapeutics do not establish in infants with CF a gastrointestinal microbiota like that in healthy infants, and we suggest that interventions that direct the gastrointestinal microbiota closer to a healthy state may provide systemic benefits to these patients during a critical window of immune programming that might have implications for lifelong health., (Copyright © 2019 American Society for Microbiology.)

Liver transplantation can lead to post-traumatic stress disorder (PTSD) in recipients, but the risk factors associated with PTSD in living donors are unknown. To investigate this progression in pediatric living donors, a cross-sectional investigation was carried out.All participants completed 2 questionnaires: a PTSD self-rating scale (PTSD-SS) and a validated Chinese version of the Medical Outcomes Study Short Form-36 (SF-36). Clinical and demographic data were collected from medical records and self-report questionnaires. Univariate analysis was conducted to identify statistical differences.The prevalence of full PTSD (all symptom clusters) and partial PTSD (2 out of 3 symptom clusters) was 12.1% and 31.1%, respectively. Those with an educational status of elementary school (P = .001), who were donors to their children (P = .008), who were in the first 6 months after transplant (P < .001), or were involved in transplants where the recipients had severe complications (P = .02) were more likely to have higher PTSD-SS scores than other groups. The non-PTSD group had a higher health-related quality-of-life score compared with the full and partial PTSD groups in the domains of physical function, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health. In addition, the occurrence of PTSD was related to a poorer quality of life.The occurrence of PTSD was common in living donors after pediatric liver transplantation. Those with a lower educational status, who were donors to their children, were in the first 6 months after transplant, or were involved in transplants where the recipients had severe complications were most likely to experience PTSD. Post-traumatic stress symptom severity was significantly associated with a poorer quality of life after transplant.

Cystic fibrosis (CF) is a genetic disease that causes patients to accumulate thick, dehydrated mucus in the lung and develop chronic, polymicrobial infections due to reduced mucociliary clearance. These chronic polymicrobial infections and subsequent decline in lung function are significant factors in the morbidity and mortality of CF. Pseudomonas aeruginosa and Streptococcus spp. are among the most prevalent organisms in the CF lung; the presence of P. aeruginosa correlates with lung function decline, and the Streptococcus milleri group (SMG), a subgroup of the viridans streptococci, is associated with exacerbations in patients with CF. Here we characterized the interspecies interactions that occur between these two genera. We demonstrated that multiple P. aeruginosa laboratory strains and clinical CF isolates promote the growth of multiple SMG strains and oral streptococci in an in vitro coculture system. We investigated the mechanism by which P. aeruginosa enhances growth of streptococci by screening for mutants of P. aeruginosa PA14 that are unable to enhance Streptococcus growth, and we identified the P. aeruginosa pqsL ::Tn M mutant, which failed to promote growth of Streptococcus constellatus and S. sanguinis Characterization of the P. aeruginosa Δ pqsL mutant revealed that this strain cannot promote Streptococcus growth. Our genetic data and growth studies support a model whereby the P. aeruginosa Δ pqsL mutant overproduces siderophores and thus likely outcompetes Streptococcus sanguinis for limited iron. We propose a model whereby competition for iron represents one important means of interaction between P. aeruginosa and Streptococcus spp. IMPORTANCE Cystic fibrosis (CF) lung infections are increasingly recognized for their polymicrobial nature. These polymicrobial infections may alter the biology of the organisms involved in CF-related infections, leading to changes in growth, virulence, and/or antibiotic tolerance, and could thereby affect patient health and response to treatment. In this study, we demonstrate interactions between P. aeruginosa and streptococci using a coculture model and show that one interaction between these microbes is likely competition for iron. Thus, these data indicate that one CF pathogen may influence the growth of another, and they add to our limited knowledge of polymicrobial interactions in the CF airway., (Copyright © 2019 American Society for Microbiology.)

Purpose: The aim of this work was to investigate the molecular characterization of a clinical Enterococcus casseliflavus strain with a resistance plasmid., Materials and Methods: En. casseliflavus EC369 was isolated from a patient in a hospital in southern China. The minimum inhibitory concentration was found by means of the agar dilution method to determine the antimicrobial susceptibilities of the strains. Whole-genome sequencing and comparative genomics analysis were performed to analyze the mechanism of antibiotic resistance and the horizontal gene transfer of the resistance gene-related mobile genetic elements., Results: En. casseliflavus EC369 showed resistance to erythromycin, kanamycin, and streptomycin, but was susceptible to vancomycin, ampicillin, and streptothricin and other antimicrobials. There were six resistance genes ( aph3 ', ant6 , bla , sat4 , and two ermB s) carried by a transposon identified on the plasmid pEC369 and a complete resistance gene cluster of vancomycin and a tet (M) gene encoded on the chromosome. This is the first complete plasmid sequence reported in clinically isolated En. casseliflavus . The plasmid with the greatest sequence identity with pEC369 was the plasmid of Enterococcus sp. FDAARGOS&#95;375, followed by the plasmids of Enterococcus faecium strains F12085 and pRE25, whereas the sequence with the greatest identity to the resistance genes carrying a transposon of pEC369 was on the chromosome of Staphylococcus aureus strain GD1677., Conclusion: The resistance profiles of En. casseliflavus EC369 might contribute to the resistance genes encoded on the plasmid. The fact that the most similar sequence to the transposon carrying resistance genes of pEC369 was encoded in the chromosome of a S. aureus strain provides insights into the mechanism of dissemination of multidrug resistance between bacteria of different species or genera through horizontal gene transfer., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Similar to other CTX-M family enzymes, KLUC is a recently identified and emerging determinant of cefotaxime resistance that has been recovered from at least three Enterobacteriaceae species, including Kluyvera cryocrescens , Escherichia coli, and Enterobacter cloacae . Whether this extended-spectrum β-lactamase (ESBL) has been disseminated among commonly isolated Enterobacteriaceae is worthy of further investigation. In this study, we screened 739 nosocomial Enterobacteriaceae isolates (240 Klebsiella pneumoniae and 499 E. coli strains) and found that one K. pneumoniae and four E. coli isolates harbored the bla KLUC gene. Three bla KLUC determinants isolated from E. coli were entirely identical to a bla KLUC-3 gene previously recovered in the same hospital. PFGE of four bla KLUC -harboring E. coli strains showed that prevalence of these determinants was most likely mediated by horizontal gene transfer but not clonal dissemination. However, the variant isolated from K. pneumoniae belonged to a novel member of the KLUC enzyme group. This newly identified enzyme (KLUC-5) has an amino acid substitution compared with previously identified KLUC-1 (G18S) and KLUC-3 (G240D). Antimicrobial susceptibility tests showed that KLUC-5 significantly reduced resistance activity to almost all the selected antimicrobials compared to previously identified KLUC-3. Site-directed mutagenesis showed that bla KLUC-5 -D240G and bla KLUC-5 -S18G significantly enhanced the MIC against its best substrate. Conjugation and S1-PFGE indicated that bla KLUC-5 was located on a transferable plasmid, which was further decoded by single-molecule, real-time sequencing. Comparative genome analysis showed that its backbone exhibited genetic homology to the IncA/C incompatibility group plasmids. A transposable element, IS Ecp1 , was detected 256-bp upstream of the bla KLUC-5 gene; this location was inconsistent with the previously identified bla KLUC-1 but congruent with the variants recovered from E. coli in the same hospital. These data provide evidence of the increasingly emerging KLUC group of ESBLs in China.

Computational modeling of heart valve dynamics incorporating both fluid dynamics and valve structural responses has been challenging. In this study, we developed a novel fully-coupled fluid-structure interaction (FSI) model using smoothed particle hydrodynamics (SPH). A previously developed nonlinear finite element (FE) model of transcatheter aortic valves (TAV) was utilized to couple with SPH to simulate valve leaflet dynamics throughout the entire cardiac cycle. Comparative simulations were performed to investigate the impact of using FE-only models vs. FSI models, as well as an isotropic vs. an anisotropic leaflet material model in TAV simulations. From the results, substantial differences in leaflet kinematics between FE-only and FSI models were observed, and the FSI model could capture the realistic leaflet dynamic deformation due to its more accurate spatial and temporal loading conditions imposed on the leaflets. The stress and the strain distributions were similar between the FE and FSI simulations. However, the peak stresses were different due to the water hammer effect induced by the fluid inertia in the FSI model during the closing phase, which led to 13-28% lower peak stresses in the FE-only model compared to that of the FSI model. The simulation results also indicated that tissue anisotropy had a minor impact on hemodynamics of the valve. However, a lower tissue stiffness in the radial direction of the leaflets could reduce the leaflet peak stress caused by the water hammer effect. It is hoped that the developed FSI models can serve as an effective tool to better assess valve dynamics and optimize next generation TAV designs., Competing Interests: The authors declare that they have no conflict of interest.

A 63-year male was admitted with abdominal pain, fever and jaundice. The contrast-enhanced computed tomography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiography showed a mass in the hepatic hilar region with dilation of the intrahepatic bile duct. The left branch of portal vein was also compressed by the mass. The patient was diagnosed as intrahepatic bile duct carcinoma and underwent the left hemihepatectomy together with right hepatic duct jejunum anastomosis (Roux-en-Y)combined with hepatoduodenal ligament lymphadenectomy. In the left intrahepatic bile duct, a mass of 3 x 2 x 2 cm was seen extending into the common hepatic bile duct. No tumor was detected in the liver parenchyma. The left portal vein compression by the tumor was confirmed during surgical exploration. Immunostaining showed hepatocyte(+), AFP(+/-), CK(+/-), which indicated that the cancerous tumor cells were derived from hepatocytes but not from bile duct epithelial cells. The final diagnosis of this patient was hepatocellular carcinoma growing in the intrahepatic bile duct.

The mitral valve (MV) is a highly complex cardiac valve consisting of an annulus, anterior and posterior leaflets, chordae tendineae (chords) and two papillary muscles. The chordae tendineae mechanics play a pivotal role in proper MV function: the chords help maintain proper leaflet coaptation and rupture of the chordae tendineae due to disease or aging can lead to mitral valve insufficiency. Therefore, the aim of this study was to characterize the mechanical properties of aged human and ovine mitral chordae tendineae. The human and ovine chordal specimens were categorized by insertion location (i.e., marginal, basal and strut) and leaflet type (i.e., anterior and posterior). The results show that human and ovine chords of differing types vary largely in size but do not have significantly different elastic and failure properties. The excess fibrous tissue layers surrounding the central core of human chords added thickness to the chords but did not contribute to the overall strength of the chords. In general, the thinner marginal chords were stiffer than the thicker basal and strut chords, and the anterior chords were stiffer and weaker than the posterior chords. The human chords of all types were significantly stiffer than the corresponding ovine chords and exhibited much lower failure strains. These findings can be explained by the diminished crimp pattern of collagen fibers of the human mitral chords observed histologically. Moreover, the mechanical testing data was modeled with the nonlinear hyperelastic Ogden strain energy function to facilitate accurate computational modeling of the human MV., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: To construct lentiviral vector that interferes with Nanog, investigate its expression in human gastric cancer cell SGC-7901-transplanted nude mice, and explore the effect of shRNA-Nanog transfection on the growth of the xenograft in mice., Methods: Lentivirus carrying shRNA-Nanog was prepared by incorporating previously validated siRNA into Nanog gene specific lentiviral vectors. The models of human gastric cancer transplantation were constructed in nude mice. The mouse models were randomly divided into lentivirus-shRNA-Nanog transfection group (experimental group), GFP infection group (empty vector group) and uninfected group (control group). The tumor volume and mass changes were measured. Small animal in vivo imaging was employed to examine the fluorescent intensity and tumor metastasis. The Nanog protein expression was determined by Western blot analysis. The apoptosis of transinfected tumor cells was analyzed by TUNEL method. Results The gene sequencing demonstrated that the recombinant lentivirus carrying shRNA-Nanog was successfully established. In vivo imaging showed that 27 days after transfection, the total fluorescent intensity in the experimental group was significantly lower than that in the empty vector group or the uninfected group. The xenograft volume and mass in the experimental group decreased significantly as compared with those in the empty vector group or the uninfected group. Western blotting indicated that the expression of Nanog protein in the experimental group was significantly lower than that in the empty vector or uninfected group. TUNEL results revealed that the apoptosis rate in the experimental group was significantly higher than that in the other two groups. No statistically significant difference was found between the empty vector group and the uninfected group., Conclusion: We successfully established Nanog gene-shRNA expression vector and capsulated it as lentivirus particles, which could inhibit the growth of xenograft in nude mice.

Background: Yersinia enterocolitica outer membrane protein A (OmpA) is one of the major outer membrane proteins with high immunogenicity. We performed the polymorphism analysis for the outer membrane protein A and putative outer membrane protein A (p-ompA) family protein gene of 318 Y. enterocolitica strains., Results: The data showed all the pathogenic strains and biotype 1A strains harboring ystB gene carried both ompA and p-ompA genes; parts of the biotype 1A strains not harboring ystB gene carried either ompA or p-ompA gene. In non-pathogenic strains (biotype 1A), distribution of the two genes and ystB were highly correlated, showing genetic polymorphism. The pathogenic and non-pathogenic, highly and weakly pathogenic strains were divided into different groups based on sequence analysis of two genes. Although the variations of the sequences, the translated proteins and predicted secondary or tertiary structures of OmpA and P-OmpA were similar., Conclusions: OmpA and p-ompA gene were highly conserved for pathogenic Y. enterocolitica. The distributions of two genes were correlated with ystB for biotype 1A strains. The polymorphism analysis results of the two genes probably due to different bio-serotypes of the strains, and reflected the dissemination of different bio-serotype clones of Y. enterocolitica.

Background/aims: To detect the feasibility of using synchronous bile duct, left lobe of liver and common hepatic artery resection without reconstruction to improve the therapeutic efficacy of HC., Methodology: A total of 19 patients with hilar cholangiocarcinoma undergoing left-sided hepatectomy, hepatic artery resection and right hepatic duct-jejunum anastomosis from June 2005 to May 2010 in our team were included prospectively in this study., Results: One case died from probable sudden myocardial infarction before discharge from hospital. Little bile leakage occurred in one case. No hepatic insufficiency developed in any cases. A follow-up of 6-66 months was applied and 11 cases were still alive at the end., Conclusions: Hepatic Arteriectomy is viable with lower total bilirubin and the excision weight up to about 30% of the standard liver.

The asymmetric, elliptical shape of a transcatheter aortic valve (TAV), after implantation into a calcified aortic root, has been clinically observed. However, the impact of elliptical TAV configuration on TAV leaflet stress and strain distribution and valve regurgitation is largely unknown. In this study, we developed computational models of elliptical TAVs based on a thin pericardial bioprosthetic valve model recently developed. Finite element and computational fluid dynamics simulations were performed to investigate TAV leaflet structural deformation and central backflow leakage, and compared with those of a nominal symmetric TAV. From the results, we found that for a distorted TAV with an elliptical eccentricity of 0.68, the peak stress increased significantly by 143% compared with the nominal circular TAV. When the eccentricity of an elliptical TAV was larger than 0.5, a central backflow leakage was likely to occur. Also, deployment of a TAV with a major calcified region perpendicular to leaflet coaptation line was likely to cause a larger valve leakage. In conclusion, the computational models of elliptical TAVs developed in this study could improve our understanding of the biomechanics involved in a TAV with an elliptical configuration and facilitate optimal design of next-generation TAV devices., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Percutaneous aortic valve (PAV) replacement is currently being investigated as an endovascular alternative to conventional open-chest valve surgery for patients with severe aortic stenosis. The results of multi-center clinical trials of PAV devices have been encouraging. However, there are serious adverse events associated with this procedure. Furthermore, long-term durability and safety of PAV need to be studied carefully. In this study, we developed a thin pericardial bioprosthetic valve model, which has similar design features of PAV. We utilized this model to investigate PAV deformation under static, pressure-only loading conditions using Finite Element method. Mechanical properties of PAV leaflet were obtained from planar biaxial testing of glutaraldehyde treated thin bovine pericardium (BP) and porcine pericardium (PP), and characterized by the Fung-elastic model. Simulations were performed to examine the effects of tissue thickness and anisotropy on the valve deformation and stress distribution. The results indicated peak stress and strain occurred in the vicinity of commissures. The peak maximum principal stresses (MPS) were reduced with the increase of leaflet tissue thickness, by 36% and 59% from the mean thickness to 0.35 mm for BP and PP, respectively. The PAV with BP leaflet had a lower peak MPS than that with PP leaflet. Moreover, leaflet material orientation had a significant influence on the peak MPS of PAV.