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Carbapenem-resistant Klebsiella pneumoniae (CRKP) is one of the leading causes of healthcare-associated infections (HAIs) and is particularly pervasive in intensive care units (ICUs). This study takes ICU layout as the research object, and integrates clinical data and bacterial genome analysis to clarify the role of separate, small wards within the ICU in controlling the transmission of CRKP.This study prospectively observed the carriage and spread of CRKP from a long-term in-hospital patient (hereafter called the Patient) colonized with CRKP in the gut and located in a separate, small ward within the ICU. The study also retrospectively investigated CRKP-HAIs in the same ICU. The relationship and transmission between CRKP isolates from the Patient and HAI events in the ICU were explored with comparative genomics.In this study, 65 CRKP-HAI cases occurred during the investigation period. Seven CRKP-HAI outbreaks were also observed. A total of 95 nonrepetitive CRKP isolates were collected, including 32 strains from the Patient in the separate small ward. Phylogenetic analysis based on core genome single-nucleotide polymorphism (cgSNP) showed that there were five possible CRKP clonal transmission events and two clonal outbreaks (A1, A2) during the study. CRKP strains from the Patient did not cause CRKP between-patient transmission or outbreaks in the ICU during the 5-year study period.The presence of a long-term hospitalized patient carrying CRKP and positioned in a separate, small ward did not lead to CRKP transmission or infection outbreaks in the ICU. Combining a small-ward ICU layout with normative HAI control measures for multidrug-resistant pathogen infection was effective in reducing CRKP transmission.

Huiqiong Liu,1 Dao Wang,1 Miaomiao Tang,1 Peisheng Jia,1 Yufeng Huo,1 Erhu Wei,1 Hao Xu,2 Xiaohui Chi,2 Huaili Wang1 1Department of Pediatric Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People’s Republic of China; 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People’s Republic of ChinaCorrespondence: Huaili Wang, Department of Pediatric Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, No. 1 Longhu East Zhonghuan Road, Zhengzhou, 450052, People’s Republic of China, Tel +86-371-66271057, Email whlek6527@126.comPurpose: With the spread of multiple drug-resistant bacteria, blaNDM-1 and mcr-9 have been detected in various bacteria worldwide. However, the simultaneous detection of blaNDM-1 and mcr-9 in Enterobacter hormaechei has been rarely reported. This study identified an E. hormaechei strain carrying both blaNDM-1 and mcr-9. We investigated the genetic characteristics of these two resistance genes in detail, elucidating various potential mechanisms by which they may be transmitted.Methods: Bacterial genomic features and possible origins were assessed by whole-genome sequencing (WGS) with Illumina and PacBio platforms and phylogenetic analysis. Subsequent investigations were performed, including antimicrobial susceptibility testing and multilocus sequence typing (MLST).Results: We isolated an E. hormaechei strain DY1901 carrying both blaNDM-1 and mcr-9 from the sputum sample. Susceptibility testing showed that the isolate was multidrug-resistant. Multiple antibiotic resistance genes and virulence genes are widely distributed in DY1901. S1-PFGE, Southern blotting, and plasmid replicon typing showed that DY1901 carried four plasmids. The plasmid carrying mcr-9 was 259Kb in size and belonged to IncHI2, while the plasmid carrying blaNDM-1 was 45Kb in length and belonged to IncX3.Conclusion: The E. hormaechei strain isolated in this study has a broad antibiotic resistance spectrum, posing a challenge to clinical treatment. Plasmids carrying mcr-9 are fusion plasmids, and those taking NDM are widely disseminated in China, suggesting that we should conduct routine genomic surveillance on such plasmids to curb the spread of drug-resistant bacteria in the region.Keywords: E. hormaechei, New Delhi metallo-β-lactamase, mcr-9, whole-genome sequencing, phylogenetic analysis

Ceftazidime/avibactam (CAZ/AVI), a combination of ceftazidime and a novel β-lactamase inhibitor (avibactam) that has been approved by the U.S. Food and Drug Administration, the European Union, and the National Regulatory Administration in China. CAZ/AVI is used mainly to treat complicated urinary tract infections and complicated intra-abdominal infections in adults, as well as to treat patients infected with Carbapenem-resistant Enterobacteriaceae (CRE) susceptible to CAZ/AVI. However, increased clinical application of CAZ/AVI has resulted in the development of resistant strains. Mechanisms of resistance in most of these strains have been attributed to bla

Shuguang Xu,1 Jinjing Tu,1 Liang Zhang,1 Yinv Chen,1 Xiaoqi Dong,1 Xiaohui Chi,2,* Hao Xu2,* 1Department of Pulmonary and Critical Care Medicine, Ningbo Medical Center Lihuili Hospital, Ningbo, People’s Republic of China; 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Hao Xu; Xiaohui Chi, Email xuhao930523@163.com; chixiaohui@zju.edu.cnPurpose: Nosocomial infections caused by New Delhi metallo-β-lactamase (NDM)-producing bacteria are prevalent worldwide. However, such diseases caused by NDM-producing Aeromonas caviae had never been reported. Our study aimed to elucidate the genomic characteristics of NDM-1-producing A. caviae isolated from hospital patients.Methods: Bacterial genomic features and possible origins were assessed by whole-genome sequencing (WGS) and phylogenetic analysis. Subsequent investigations include antimicrobial susceptibility testing and multilocus sequence typing (MLST).Results: We identified here two NDM-1-producing A. caviae isolates from bacteremia. Susceptibility testing showed that two isolates were multi-drug resistant and shared a similar resistance profile and were only sensitive to amikacin and trimethoprim/sulfamethoxazole. Both A. caviae isolates carry the carbapenem resistance gene blaNDM-1 and also have antibiotic resistance genes such as β-lactams, AmpC enzymes, macrolides, aminoglycosides, and quinolones. S1-PFGE and Southern blot analysis were negative. Whole-genome sequencing and comparative analysis revealed that these two isolates shared a close relationship.Conclusion: To the best of our knowledge, this work describes the first detection of non-plasmid encoded blaNDM-1 in A. caviae. The A. caviae isolated in this study has a broad drug resistance spectrum. Phenotypic and molecular analysis indicated the two isolates belong to the same clone. Routine genomic surveillance of this species is now necessary to effectively curb the further dissemination of carbapenem-resistant bacteria in the region.Keywords: Aeromonas caviae, New Delhi metallo-β-lactamase, whole-genome sequencing, SNP, phylogenetic analysis

Weijie Cao,1,* Lina Guan,1,* Xiaoning Li,1 Ran Zhang,1 Li Li,1 Suping Zhang,1 Chong Wang,1 Xinsheng Xie,1 Zhongxing Jiang,1 Dingming Wan,1 Xiaohui Chi2 1Department of Hematology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People’s Republic of China; 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Weijie Cao Email caoweijie2003@126.comPurpose: To explore the epidemiological characteristics and risk factors of bloodstream infections (BSI) in patients who develop agranulocytosis fever after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study also provides a basis for the clinical treatment of BSI.Methods: A retrospective analysis of 397 allo-HSCT patients in the Department of Hematology of our hospital was conducted from January 2013 to December 2017 to analyze the incidence of BSI, the distribution and types of pathogenic bacteria, and drug resistance rates. We also determined whether various parameters are risk factors to BSI, including the patient age, gender, disease type, transplantation method, stem cell source, pre-treatment with anti-thymocyte globulin (ATG), and agranulocytosis time.Results: Among the 397 allo-HSCT patients, 294 had a fever during the period of agranulocytosis, and 52 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 17.7% (52/294). Among the 60 pathogens detected, 43 (71.67%), 10 (16.67%), and 7 (11.67%) were Gram negative strains, Gram positive strains, and fungi, respectively. The most common bacteria were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The detection rate of extended-spectrum β-lactamase (ESBL) was 40.0%, and carbapenem-resistant Enterobacteriaceae (CRE) accounted for 17.9%. Single-factor and multi-factor analyses showed that pre-treatment with ATG, agranulocytosis time (≥ 21 days), and stem cell source were risk factors for BSI.Conclusion: We found that in our hospital, BSIs in allo-HSCT patients are mainly caused by Gram-negative bacteria, and the resistance rate to carbapenem drugs is high. Pre-treatment with ATG, agranulocytosis time (≥ 21 days), and stem cell source are risk factors for BSI.Keywords: hematopoietic stem cell transplantation, agranulocytosis, BSI, pathogenic bacteria, risk factors

With the spread of multiple drug-resistant bacteria,Bacterial genomic features and possible origins were assessed by whole-genome sequencing (WGS) with Illumina and PacBio platforms and phylogenetic analysis. Subsequent investigations were performed, including antimicrobial susceptibility testing and multilocus sequence typing (MLST).We isolated anThe

Stanford type A acute aortic dissection (AAD) is a life-threatening illness that presents with chest pain and hemodynamic instability. AAD prompt and accurate evaluation and management are critical for survival as it is a cardiac surgical emergency. The initial treatment of AAD mandates strict blood pressure stabilization with intravenous antihypertensive medications. The progressive nature of the disease will increase the mortality as time elapses between diagnosis and surgical intervention. In addition, the patient’s blood pressure control is challenged in the presence of renal failure requiring hemodialysis. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or named 2019-nCoV) pneumonia was a newly underrecognized illness (COVID-19 [coronavirus disease 2019]). COVID-19 can cause severe acute respiratory distress syndrome, acute kidney injury, heart injury, and liver dysfunction, which would aggravate the progress of aortic dissection. In this article, we report the successful anesthesia management in a pneumonia patient with AAD complicated with renal failure during the COVID-19 epidemic period, who underwent emergency surgery and deep hypothermic circulatory arrest repair.

Background Citrobacter freundii is the most common class of pathogens in the genus Citrobacter and is an important pathogen associated with certain underlying diseases or immune dysfunction. The aim of this study was to elucidate the resistance mechanism of clinically derived carbapenem-resistant C. freundii isolate and to characterize the genetic environment and delivery pattern of the IncN1 plasmid carrying the bla IMP-4 gene from C. freundii isolate. Materials and methods We identified a clinical isolate of C. freundii L91 carrying bla IMP-4 and performed phylogenetic analysis by whole-genome sequencing. The complete genomic sequence of L91 was obtained using the Illumina HiSeq 4000-PE150 and PacBio RS II platforms. Antimicrobial susceptibility testing was determined by the VITEK 2 system. Plasmid characteristics were presented by S1-pulsed-field gel electrophoresis (PFGE), Southern blotting and conjugation experiments. Results S1-PFGE, Southern blot and conjugation assay confirmed the presence of bla IMP-4 genes on a conjugative plasmid in this isolate. C. freundii L91 and transconjugant L91-E. coli 600 strains both showed resistance to carbapenems. In silico analysis further showed that pIMP-4-L91 is an IncN1 plasmid with a length of 51,042 bp. Furthermore, bla IMP-4 gene was found encoded in the bla IMP-4-qacG2-aacA4-catB3 cassette array within a class 1 integron. A conserved structure sequence (ΔISKpn27-bla IMP-4-ΔISSen2-hp-hp-IS6100) was found in the upstream and downstream of the bla IMP-4. Conclusion We performed a comprehensive phylogenetic analysis of carbapenemase-resistant C. freundii and elucidated the resistance mechanism of clinically derived C. freundii L91. Not only that, we also found that the bla IMP-4 gene is located on the IncN1 plasmid and has a horizontal transfer function and a certain ability to spread. To lower the risk of the dissemination of such C. freundii isolates in clinical settings, more surveillance is needed in the future.

Background During brain development, volatile anesthetic can rapidly interfere with physiologic patterns of dendritic development and synaptogenesis and impair the formation of precise neuronal circuits. KCC2 plays vital roles in spine development and synaptogenesis through its Cl- transport function and structural interactions with the spine cytoskeleton protein 4.1 N. The aim of this study was to dissect the mechanism of volatile anesthetics, which impair dendritic development and synaptogenesis via mediation of KCC2 cleavage. Methods Westernblotting was employed to assess the expression change of NR2B, NR2A, calpain-1, calpain-2, KCC2, and 4.1 N protein of rat (PND 5). Co-immunoprecipitation was applied to demonstrate the interaction between KCC2 and 4.1 N protein. Long-term cognitive deficiency was assessed by MWM. Lentivirus-calpain-2 was administered by hippocampus stereotaxic injection. Results There was a significant increase in the level of NR2B instead of NR2A exposure to isoflurane. Calpain-2 was excessively activated via NR2B after 6 h of isoflurane exposure. The expression of plasmalemmal KCC2 and 4.1 N protein was significantly decreased treated with isoflurane. The isoflurane group showed longer traveled distance, prolonged escape latency, less time spent in the target quadrant, and decreased platform crossings. Pretreatment with ifenprodil and downregulated calpain-2 expression significantly alleviated these neurotoxicity responses and cognitive deficiency after isoflurane exposure. Conclusions A significant increase in NR2B, excessive activation of calpain-2 and increased cleavage of plasmalemmal KCC2, are involved in isoflurane-induced neurotoxicity and long-term cognitive deficiency. Blocking NR2B and calpain-2 activity significantly attenuated these responses. The KCC2 cleavage mediated by NR2B and calpain-2 is a major determinant of isoflurane-induced long-term cognitive deficiency.

Carbapenem-resistantA prospective study was conducted on patients with mechanical ventilation from July 2018 to December 2019 in a tertiary hospital. Multi-genomics studies (16S rRNA amplicon, metagenomics, and whole-genome sequencing [WGS]) of endotracheal deep aspirate (ETA) were performed.Fifty-two ICU patients were enrolled, including 24 with CRAB VAP (CRAB-I), 22 with CRAB colonization (CRAB-C), and six CRAB-negative patients (infection-free) (CRAB-N). Diversity of pulmonary microbiota was significantly lower in CRAB-I than in CRAB-C or CRAB-N (mean Shannon index, 1.79 vs. 2.73 vs. 4.81,Lower respiratory tract microbiota dysbiosis including elevated relative abundance of

Background: Brucellosis is the most widespread zoonosis worldwide and one of the most neglected zoonotic diseases. At present, large-scale farms are growing rapidly, increasing the risk of disease transmission. Objectives: In this study, the propensity score matching (PSM) method was used to analyze the epidemiological characteristics of brucellosis and explore the risk factors of brucellosis infection in Hulunbuir, Inner Mongolia, China. Methods: A questionnaire for brucellosis was designed based on general knowledge and the protection of key groups of brucellosis. Epidata 13.0 software was used to establish the questionnaire, and propensity score matching was used to select cases that met the requirements of case-controls. Results: A total of 152 cases and 456 controls were included. The results of the study show that feeding livestock, carrying lambs regularly, and raising livestock without protective measures can increase the risk of brucellosis infection. Conclusions: Behavioral factors are the main risk factors for brucellosis, and livestock keepers should strengthen self-protection when working.

Ganfeng Liang,1,* Yuting Rao,2,3,* Shuang Wang,4 Xiaohui Chi,2 Hao Xu,2 Yang Shen1 1Department of Infectious Diseases, The First Hospital of Taizhou, Taizhou, People’s Republic of China; 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People’s Republic of China; 3Department of Laboratory Medicine, Puyang Oil Field General Hospital, Puyang, People’s Republic of China; 4Institute of Bacterial Infection Disease Control, Shandong Centre for Disease Control and Prevention, Jinan, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yang Shen; Hao Xu Email Shenyanghtt@163.com; xuhao0523@zju.edu.cnBackground: The emergence of the plasmid-borne colistin-resistant gene (mcr-1) poses a great threat to human health. What is worse, the recent observations of the coexistence of mcr-1 with carbapenemase encoding genes in some bacteria caused even more concern. Yet, there is a lack of observations of such strains in the human gut.Methods: The isolation of E. coli L889 was performed on selective medium plates. Antibiotic susceptibilities were determined by an agar dilution and a broth microdilution method. Multi-locus sequence typing (MLST) and acquired resistance genes were also characterized. Transferability of blaNDM-9/mcr-1-carrying plasmids was determined by conjugation, replicon typing and S1-Pulsed-field gel electrophoresis (S1-PFGE), and Southern blotting. The sequences of these plasmids were analyzed by using whole-genome sequencing with Illumina Novaseq and Nanopore platforms.Results: E. coli L889 was identified as ST1101 concomitantly carrying blaNDM-9 and mcr-1 from a stool sample. Antimicrobial susceptibility tests showed that it was resistant to various antimicrobial agents and only susceptible to tigecycline. Notably, blaNDM-9 was located on a ∼ 114-kb untypable plasmid, while mcr-1 was located on a ∼ 63-kb IncI2 plasmid.Conclusion: Our research, to our knowledge, first reported an ST1101 E. coli strain with an untypeable blaNDM-9-harbouring plasmid and an IncI2 mcr-1-carrying plasmid. The colonized E. coli strains potentially contribute to the dissemination and transfer of blaNDM-9 and mcr-1 to clinical isolates, which is a considerable threat to public health and should be closely monitored.Keywords: blaNDM-9, mcr-1, gut, Escherichia coli, ST1101

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a common cause of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients, but infection and colonization are difficult to distinguish which aggravates the abuse of antimicrobial drugs and further accelerates the evolution of drug resistance. We sought to provide new clues for the diagnosis, pathogenesis and treatment of CRAB VAP based on lower respiratory tract (LRT) microbiota. Methods: A prospective study was conducted on patients with mechanical ventilation from July 2018 to December 2019 in a tertiary hospital. Multi-genomics studies (16S rRNA amplicon, metagenomics and whole-genome sequencing [WGS]) of endotracheal deep aspirate (ETA) were performed. Results: Fifty-two ICU patients were enrolled, including 24 with CRAB VAP (CRAB-I), 22 with CRAB colonization (CRAB-C), and six CRAB-negative patients (infection-free) (CRAB-N). Diversity of pulmonary microbiota was significantly lower in CRAB-I than in CRAB-C or CRAB-N (mean Shannon index, 1.79 vs. 2.73 vs. 4.81, PAcinetobacter was most abundant in CRAB-I (76.19%), moderately abundant in CRAB-C (59.14%), and least abundant in CRAB-N (11.25%), but its interactions with other genera exhibited the opposite pattern. Metagenomics and WGS analysis showed that virulence genes were more abundant in CRAB-I than in CRAB-C. Multi-locus sequence typing (MLST) of 46 CRAB isolates revealed that the main types were ST208 (30.43%) and ST938 (15.22%), with no difference between CRAB-I and CRAB-C. Conclusions: LRT microbiota dysbiosis including elevated relative abundance of Acinetobacter and reduced bacterial interactions, and virulence enrichment may lead to CRAB VAP.

Purpose Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae bacteria causes nosocomial infections worldwide. However, KPC-producing K. pneumoniae outbreak has never been reported in Shandong Province, China. The purpose of our study was to elucidate the epidemiological and drug resistance mechanisms of KPC-producing K. pneumoniae strains collected from a large teaching hospital in Shandong during the outbreak. Moreover, we attempted to characterize the genetic environment and phylogenetic analysis of bla KPC-2 in outbreak isolates. Methods We monitored a 64-day outbreak of infection in a general hospital in Shandong Province, and the bacteria causing the infection were all ST11-type K. pneumoniae. The genotype correlation of KPC-producing K. pneumoniae isolates was assessed by whole-genome sequencing (WGS) phylogenetic analysis. Subsequent studies included antibiotic susceptibility testing, multilocus sequence typing (MLST) and S1-pulsed-field gel electrophoresis (S1-PFGE), Southern blot hybridization. Results From February 1, 2018 to April 5, 2018, 14 KPC-producing K. pneumoniae isolates from different wards were collected. All 14 isolates were resistant to carbapenems and carried the extended-spectrum β-lactamase (ESBL) gene as well as fosA, and sul genes. Whole-genome analysis showed that all 14 the outbreak isolates were all ST11 type. The bla KPC-2 carrying plasmids were all belong to IncFIIK2 type, and the size ranged from 94 kb to 368 kb. Conclusion As far as we know, this report first describes the genomics characterization of KPC-2-producing K. pneumoniae outbreak isolates from Shandong Province, China. In our study, these isolates appeared to be cloned, and ST11 K. pneumoniae was the major clone caused the outbreak. Therefore, routine surveillance of such strains in this region is urgently warranted.

It is becoming increasingly recognized that the environment plays an important role both in the emergence and in dissemination of antibiotic-resistant bacteria (ARB), Mechanisms and factors facilitating this development are, however, not yet well understood. The high detection rate of CTX-M genes in environmental sources provides an opportunity to explore this issue. In this study, 88 CTX-M-producing Escherichia coli were isolated from 30 pig feces samples from 30 pig farms and 201 environmental samples. CTX-M-producing E. coli was detected with the following frequencies in the different types of samples: pig feces, 73%; river water, 64%; river sediment, 52%; wastewater, 31%; drinking water, 23%; outlet sediment, 21%; soil, 17%; and vegetables, 4.4%. Dissemination of CTX-M-producing E. coli to different environmental matrices was evaluated by analyzing the genetic relatedness of isolates from different environmental sources, and putative transmission routes through bird feces, pig feces, drinking water, river sediment, river water, and wastewater were hypothesized. Dissemination through these routes is likely facilitated by anthropogenic activities and environmental factors. Wild birds as potential vectors for dissemination of CTX-M-producing E. coli have the capacity to spread ARB across long distances. Regional dissemination between different environmental matrices of CTX-M-producing E. coli increases the exposure risk of humans and animals in the area. Funding Agencies|National Natural Science Foundation of China [41771499, 81361138021]; Fundamental Research Funds of Shandong University [2018JC102]; Swedish Research Council; Public Health Agency of Sweden [D0879801]; Swedish Research Council Formas [2016-00640]

Antibiotic resistance among gram-negative bacteria is increasingly becoming a problem of global concern. Particularly problematic is the emergence of resistance to last-resort antibiotics such as carbapenems and colistin. The increasing number of reports on the plasmid-mediated colistin resistance gene mcr-1 in isolates worldwide is raising concerns for the future usefulness of this class of antibiotics. Dissemination of mcr-1 is believed to have originated mainly from animal breeding, however, the role of the environment as a transmission source is not yet fully understood. In the current study, 89 extended-spectrum β-lactamase-producing Escherichia coli isolated from 231 samples from different environmental sources in 12 villages in a rural area of Shandong, China, were screened for mcr-1. 17 (19.1%) mcr-1-positive isolates were found from different environmental sources, aggregated in 6 villages. Plasmids of three different Inc-groups carrying mcr-1 were confirmed, indicating that the widespread geographical distribution of mcr-1 in the local area is due to a number of different plasmids. Additionally, almost a third (29.4%) of the isolates carried virulence factors associated to intestinal pathogenic E. coli. These results illustrate the high complexity of the transmission patterns of mcr-1 among different environmental matrices on a local scale and the potential for the environment to facilitate dissemination and emergence of antibiotic-resistant and virulent strains of bacteria.

Human mesenchymal stem cell-based tumor therapeutic gene delivery is regarded as a promising strategy for the treatment of glioblastoma (GBM). However, the efficiency of these stem cells to home to the target sites limits their potential curative effect and clinical application. In this work, we provide a novel pretreatment approach for enhancing the homing capacity of human adipose-derived mesenchymal stem cells (hAMSCs) for stem cell-based tumor gene delivery for GBM therapy. Pre-exposure of these stem cells to TGF-β resulted in enhanced homing ability to GBM through increasing CXC chemokine receptor 4 (CXCR4) expression, as evidenced by a diminishing homing capacity when inhibition of the TGF-β receptor II and CXCR4 was applied. In addition, by pretreating hAMSCs expression of tumor necrosis factor-related apoptosis-inducing ligand with TGF-β, we achieved significant enhancements in the therapeutic efficacy as demonstrated by an increased number of migrated hAMSCs to target sites, decreased tumor volume, and prolonged survival time in a murine model of GBM. These findings highlight a straightforward method in which cell preconditioning methodology is utilized to promote therapeutic efficacy of a biological treatment for GBM.

Background The emergence of the plasmid-borne colistin-resistant gene (mcr-1) poses a great threat to human health. What is worse, the recent observations of the coexistence of mcr-1 with carbapenemase encoding genes in some bacteria caused even more concern. Yet, there is a lack of observations of such strains in the human gut. Methods The isolation of E. coli L889 was performed on selective medium plates. Antibiotic susceptibilities were determined by an agar dilution and a broth microdilution method. Multi-locus sequence typing (MLST) and acquired resistance genes were also characterized. Transferability of blaNDM-9/mcr-1-carrying plasmids was determined by conjugation, replicon typing and S1-Pulsed-field gel electrophoresis (S1-PFGE), and Southern blotting. The sequences of these plasmids were analyzed by using whole-genome sequencing with Illumina Novaseq and Nanopore platforms. Results E. coli L889 was identified as ST1101 concomitantly carrying blaNDM-9 and mcr-1 from a stool sample. Antimicrobial susceptibility tests showed that it was resistant to various antimicrobial agents and only susceptible to tigecycline. Notably, blaNDM-9 was located on a ~114-kb untypable plasmid, while mcr-1 was located on a ~63-kb IncI2 plasmid. Conclusion Our research, to our knowledge, first reported an ST1101 E. coli strain with an untypeable blaNDM-9-harbouring plasmid and an IncI2 mcr-1-carrying plasmid. The colonized E. coli strains potentially contribute to the dissemination and transfer of blaNDM-9 and mcr-1 to clinical isolates, which is a considerable threat to public health and should be closely monitored.

Background To investigate the antimicrobial profiles and genomic characteristics of MDR-Citrobacter spp. strains isolated from Fennec fox imported from Sudan to China. Methods Four Citrobacter spp. strains were isolated from stool samples. Individual fresh stool samples were collected and subsequently diluted in phosphate buffered saline as described previously. The diluted fecal samples were plated on MacConkey agar supplemented with 1 mg/l cefotaxime and incubated for 20 h at 37 °C. Matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI–TOF–MS) was used for identification. Antimicrobial susceptibility testing was performed using the broth microdilution method. Whole-genome sequencing was performed on an Illumina Novaseq-6000 platform. Acquired antimicrobial resistance genes and plasmid replicons were detected using ResFinder 4.1 and PlasmidFinder 1.3, respectively. Comparative genomic analysis of 277 Citrobacter genomes was also performed. Results Isolate FF141 was identified as Citrobacter cronae while isolate FF371, isolate FF414, and isolate FF423 were identified as Citrobacter braakii. Of these, three C. braakii isolates were further confirmed to be extended-spectrum β-lactamases (ESBL)-producer. All isolates are all multidrug resistance (MDR) with resistance to multiple antimicrobials. Plasmid of pKPC-CAV1321 belong to incompatibility (Inc) group. Comparative genomics analysis of Citrobacter isolates generated a large core-genome. Genetic diversity was observed in our bacterial collection, which clustered into five main clades. Human, environmental and animal Citrobacter isolates were distributed into five clusters. Conclusions To our knowledge, this is the first investigation of MDR-Citrobacter from Fennec Fox. Our phenotypic and genomic data further underscore the threat of increased ESBL prevalence in wildlife and emphasize that increased effort should be committed to monitoring the potentially rapid dissemination of ESBL-producers with one health perspective.

The authors have requested that this preprint be removed from Research Square.

Clostridioides difficile is the most common pathogen causing antibiotic-associated diarrhea. Previous studies showed that diverse sources, aside from C. difficile infection (CDI) patients, played a major role in C. difficile hospital transmission. This study aimed to investigate relationships and transmission potential of C. difficile strains from different sources. A prospective study was conducted both in the intensive care unit (ICU) and six livestock farms in China in 2018–2019. Ninety-eight strains from CDI patients (10 isolates), asymptomatic hospitalized carriers (55), the ICU environment (12), animals (14), soil (4), and farmers (3) were collected. Sequence type (ST) 3/ribotype (RT) 001, ST35/RT046, and ST48/RT596 were dominant types, distributed widely in multiple sources. Core-genome single-nucleotide polymorphism (cgSNP) analysis showed that hospital and farm strains shared several common clonal groups (CGs, strains separated by ≤ 2 cgSNPs) (CG4/ST3/RT001, CG7/ST35/RT046, CG11/ST48/RT596). CDI patients, asymptomatic carriers, and the ICU environment strains also shared several common CGs. The number of virulence genes was not statistically different between strains from different sources. Multi-source strains in the same CG carried identical virulence gene sequences, including pathogenicity genes at the pathogenicity locus and adhesion-related genes at S-layer cassette. Resistance genes (ermB, tetM, etc.) were widespread in multiple sources, and multi-source strains in the same CG had similar resistance phenotypes and carried consistent transposons and plasmid types. The study indicated that interspecies and cross-regional transmission of C. difficile occurs between animals, the environment, and humans. Community-associated strains from both farms and asymptomatic hospitalized carriers were important reservoirs of CDI in hospitals.

Background: Bronchoscopes has been linked to the outbreaks of nosocomial infections. We aim to investigate the phenotypic and genomic profiles of bronchoscope-associated Klebsiella aerogenes isolates, and their association with genome public available isolates from human and environment.Methods: We performed a prospective single-center study sampling echoendoscopes after clinical use and after normal decontamination procedures. Bacterial screening was conducted by culturing the sample on Mueller-Hinton agar plates. Antimicrobial susceptibility testing was performed using the broth microdilution method. Whole-genome sequencing of K. aerogenes isolates was performed using an Illumina HiSeq system and comparative genomics analysis were conducted.Results: Over the 5-month period, a total of 358 isolates and 13 isolates were recovered from samples after clinical procedures and samples after decontamination procedures, respectively. Antimicrobial susceptibility testing found 7 K. aerogenes isolates to exhibit low-level resistance to antimicrobial agents. Among 7 K. aerogenes isolates, we found 5 sequence types (STs). Whole genome sequencing and comparison analysis observed the genetic diversity in our bacterial collection, which clustered into three main clades. Furthermore, we identified a total of 43 antimicrobial resistance genes in the K. aerogenes core genomes. As expected, human isolates encoded more antimicrobial resistance genes than that environmental isolates. Conclusions: This study first described the phenotypic and genomics characteristics of bronchoscope-associated K. aerogenes. The present observations demonstrated that broadly investigation of specific pathogens using publicly available global genomes offered the opportunity to identify prevalent clones associated with various hosts, sources, and geographical locations.

Few studies have reported the implications of performing endotracheal intubation for critically ill COVID-19 patients admitted to intensive care units (ICUs). Therefore, this study aimed to summarize the outcomes of COVID-19 patients in the ICU following endotracheal intubation and provide a clinical reference for the high-risk procedure. From February 1 to February 18, 2020, we enrolled 59 critically ill COVID-19 patients who received emergency endotracheal intubation in the ICUs of Tongji Hospital. We recorded demographic information, laboratory parameters, comorbidities, changes in vital signs pre- and post-intubation, the airway grade, intubation success rate using three types of laryngoscopes, and the experience of intubators. Follow-up evaluations were performed for all proceduralists to monitor nosocomial infections. The majority of the patients requiring intubation were elderly and had at least one comorbidity. Of the patients, 86.4% developed hypoxia before intubation. The first and second attempts of successful endotracheal intubation with the Macintosh laryngoscope (70.0% and 83.3%), Airtraq videolaryngoscope (93.5% and 80%), and UE videolaryngoscope (88.9% and 100%) were performed. Notably, SpO(2)

Background Citrobacter freundii is the most common class of pathogens in the genus Citrobacter and is an important pathogen associated with certain underlying diseases or immune dysfunction. The aim of this study was to elucidate the resistance mechanism of clinically derived carbapenem-resistant C. freundii isolate and to characterize the genetic environment and delivery pattern of the IncN1 plasmid carrying the blaIMP-4 gene from C. freundii isolate. Materials and Methods We identified a clinical isolate of C. freundii L91 carrying blaIMP-4 and performed phylogenetic analysis by whole-genome sequencing. The complete genomic sequence of L91 was obtained using the Illumina HiSeq 4000-PE150 and PacBio RS II platforms. Antimicrobial susceptibility testing was determined by the VITEK 2 system. Plasmid characteristics were presented by S1-pulsed-field gel electrophoresis (PFGE), Southern blotting and conjugation experiments. Results S1-PFGE, Southern blot and conjugation assay confirmed the presence of blaIMP-4 genes on a conjugative plasmid in this isolate. C. freundii L91 and transconjugant L91-E. coli 600 strains both showed resistance to carbapenems. In silico analysis further showed that pIMP-4-L91 is an IncN1 plasmid with a length of 51,042 bp. Furthermore, blaIMP-4 gene was found encoded in the blaIMP-4-qacG2-aacA4-catB3 cassette array within a class 1 integron. A conserved structure sequence (ΔISKpn27-blaIMP-4-ΔISSen2-hp-hp-IS6100) was found in the upstream and downstream of the blaIMP-4. Conclusion We performed a comprehensive phylogenetic analysis of carbapenemase-resistant C. freundii and elucidated the resistance mechanism of clinically derived C. freundii L91. Not only that, we also found that the blaIMP-4 gene is located on the IncN1 plasmid and has a horizontal transfer function and a certain ability to spread. To lower the risk of the dissemination of such C. freundii isolates in clinical settings, more surveillance is needed in the future.

Various lines of evidence suggest that neonatal exposure to general anesthetics, especially repeatedly, results in neuropathological brain changes and long-term cognitive impairment. Although progress has been made in experimental models, the exact mechanism of GA-induced neurotoxicity in the developing brain remains to be clarified. Sirtuin 1 (SIRT1) plays an important role in synaptic plasticity and cognitive performance, and its abnormal reduction is associated with cognitive dysfunction in neurodegenerative diseases. However, the role of SIRT1 in GA-induced neurotoxicity is unclear to date. In this study, we found that the protein level of SIRT1 was inhibited in the hippocampi of developing mice exposed to sevoflurane. Furthermore, the SIRT1 inhibition in hippocampi was associated with brain-derived neurotrophic factor (BDNF) downregulation modulated by methyl-cytosine-phosphate-guanine–binding protein 2 (MeCP2) and cAMP response element-binding protein (CREB). Pretreatment of neonatal mice with resveratrol nearly reversed the reduction in hippocampal SIRT1 expression, which increased the expression of BDNF in developing mice exposed to sevoflurane. Moreover, changes in the levels of CREB and MeCP2, which were considered to interact with BDNF promoter IV, were also rescued by resveratrol. Furthermore, resveratrol improved the cognitive performance in the Morris water maze test of the adult mice with exposure to sevoflurane in the neonatal stage, without changing motor function in the open field test. Taken together, our findings suggested that SIRT1 deficiency regulated BDNF signaling via regulation of the epigenetic activity of MeCP2 and CREB, and resveratrol might be a promising agent for mitigating sevoflurane-induced neurotoxicity in developing mice.

This study was conducted to explore the prevalence and transmission of mcr-1 Escherichia coli among healthy rural residents in Shandong, China, and to provide theoretical basis for the prevention and control of spread and treatment of multi-drug resistant Escherichia coli. A total of 218 healthy residents from 3 villages in Guan County, Shandong Province, China were included in this study, and their fecal samples were collected. Colistin-resistant Escherichia coli were selected, and their drug sensitivity and plasmids' transferability were measured. After analysis, some conclusions can be drawn. The colistin-resistant Escherichia coli, most strains of which are MDROs, is common and highly transmissible in healthy residents in rural areas in China. Interventions should be implemented to prevent the spread of colistin-resistant Escherichia coli through health education and tighter regulation of antibiotics.

Xiaohui Chi,Man Li,Wei Mei,Mingfeng Liao Department of Anesthesiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China Introduction: Acute pain is a common complication following cesarean section under general anesthesia. Post–cesarean section pain management is important for both the mother and the newborn. This study compared the effects of patient-controlled intravenous analgesia (PCIA) using sufentanil or tramadol on postoperative pain control and initiation time of lactation in patients who underwent cesarean section under general anesthesia.Methods: Primiparas (n=146) scheduled for cesarean section under general anesthesia were randomized to receive PCIA with sufentanil or tramadol. Movement-evoked and rest-pain intensity were assessed by the Numerical Rating Scale (NRS) postoperatively. The number of PCIA attempts, amount of drug consumed, initiation time of lactation, and Quality of Recovery Score 40 (QoR-40) were recorded at 4, 8, 12, and 24h postoperatively. Pre- and postoperative serum prolactin levels were recorded.Results: No between-group difference existed in the NRS at rest at any time point postoperatively. Patients on sufentanil had more movement-evoked pain and a higher sedation score at 4, 8, and 12 h postoperatively, as compared with the tramadol group. At 24 h, the QoR-40 was higher in the tramadol group compared with the sufentanil group. No significant between-group differences were present in patient satisfaction and nausea/vomiting scores. Postpartum prolactin levels were significantly higher in the tramadol group versus the sufentanil group, corresponding with a significant delay in initiation of lactation in the latter.Conclusion: PCIA with tramadol may be preferred due to lower movement-evoked pain, higher quality of recovery, and earlier lactation in patients following cesarean section under general anesthesia. Keywords: sufentanil, tramadol, cesarean section, patient-controlled analgesia, prolactin&nbsp

Infections caused by carbapenem-resistant Enterobacteriaceae are a growing concern worldwide. Raoultella ornithinolytica is a species in the Enterobacteriaceae family which can cause hospital-acquired infections and is sporadically reported as carbapenem-resistant from human and environmental sources. In this study, we firstly report on an NDM-1-producing R. ornithinolytica, Rao166, isolated from drinking water in an animal cultivation area in China. In addition to carbapenem-resistance, Rao166 was resistant to several other antibiotics including gentamicin, sulfamethoxazole-trimethoprim, tetracycline and fosfomycin. Rao166 carried a novel IncFIC-type megaplasmid, 382,325 bp in length (pRAO166a). A multidrug resistance region, 60,600 bp in length, was identified in the plasmid containing an aac(3)-IId-like gene, aac(6')-Ib-cr, bla

It is becoming increasingly recognized that the environment plays an important role both in the emergence and in dissemination of antibiotic-resistant bacteria (ARB), Mechanisms and factors facilitating this development are, however, not yet well understood. The high detection rate of CTX-M genes in environmental sources provides an opportunity to explore this issue. In this study, 88 CTX-M-producing

Infections caused by carbapenem-resistant Enterobacteriaceae are a growing concern worldwide. Raoultella ornithinolytica is a species in the Enterobacteriaceae family which can cause hospital-acquired infections and is sporadically reported as carbapenem-resistant from human and environmental sources. In this study, we firstly report on an NDM-1-producing R. ornithinolytica, Rao166, isolated from drinking water in an animal cultivation area in China. In addition to carbapenem-resistance, Rao166 was resistant to several other antibiotics including gentamicin, sulfamethoxazole-trimethoprim, tetracycline and fosfomycin. Rao166 carried a novel IncFIC-type megaplasmid, 382,325 bp in length (pRAO166a). A multidrug resistance region, 60,600 bp in length, was identified in the plasmid containing an aac(3)-IId-like gene, aac(6′)-Ib-cr, blaDHA-1, blaTEM-1B, blaCTX-M-3, blaOXA-1, blaNDM-1, qnrB4, catB3, arr-3, sul1, and tet(D). Results from virulence assays implied that Rao166 has considerable pathogenic potential. Although pRAO166a was found to be non-transmissible, dissemination of the NDM-1 producing strain may occur from well water to humans or animals through cross-contamination during food preparation or directly via drinking water, and potentially lead to difficult-to-treat infections. Thus, contamination of well water by this carbapenem-resistant and presumptively virulent strain of R. ornithinolytica should be considered a potential public health risk.

In order to improve operational effectiveness against the stiff surface targets, deep underground targets and the armored vehicles et al, guidance laws considering the terminal constraints on miss distance as well as the impact angle are derived in this paper. According to the dynamics and kinematics of the relative moving relations of the missiles against a stationary target in three-dimensional space, a three-dimensional impact angle constrained guidance law, based on the sliding mode control theory, is derived. Then, the extended trajectory shaping guidance law using the linear quadratic optimal control theory is analyzed and extended to the three-dimensional space to meet the terminal impact angle requirement. Finally, compared with the classical augmented proportional navigation guidance (APNG), numerical simulation results are presented to confirm the validity and superiority of the derived adaptive sliding mode guidance (ASMG) and the deduced extended trajectory shaping guidance (ETSG).

To compare the differences of postoperative patient-controlled intravenous analgesia for laparoscopic cholecystectomy and gynecological laparoscopy in female patients.This retrospective study included 645 female patients received laparoscopic cholecystectomy or gynecological laparoscopy (laparoscopic oophorocystectomy/myomectomy) between January 2011 and July 2012 in Tongji Hospital. Among them, 207 cases of sufentanil-tramadol patient-controlled intravenous analgesia (PCIA) were enrolled and divided into 2 groups:77 cases in laparoscopic cholecystectomy group, and 130 cases in gynecological laparoscopy group. The pressing frequency and consumption of PCIA, localization and quality of postoperative pain, visual analogue scale (VAS) at 4-6 h, 8-12 h, 18-24 h after surgery, and adverse effect were compared by t-test,χ(2) test, Fisher exact test or Mann-Whitney test.There was no statistical difference of age, body mass index, and operation time between the two groups (all P0.05). As compared with the gynecological laparoscopy group (3 (4)), PCIA pressing frequency was higher in the laparoscopic cholecystectomy group (5 (7)), but there was no statistical difference (Z = -1.747, P = 0.081). PCIA consumption in the laparoscopic cholecystectomy group (79 (33) ml) was higher than that in the gynecological laparoscopy group (48 (30) ml) (Z = -6.267, P = 0.000). The postoperative pain localization and quality were different in the two groups, the patients in the laparoscopic cholecystectomy group experienced dull pain in lower abdomen, but the ones in the gynecological laparoscopy group had distending pain in upper abdomen and piercing pain around scapula. The differences of 4-6 h, 8-12 h, 18-24 h VAS scores in the two groups had no statistical significance (all P0.05). The total incidence of postoperative adverse effect between the two groups had no statistical significant difference (laparoscopic cholecystectomy group:11.7%, gynecological laparoscopy group:16.2%) (χ(2) = 0.778, P = 0.378). The incidence of dizziness was higher in the gynecological laparoscopy group (6.2%) than that in the laparoscopic cholecystectomy group (0) (Fisher exact test:P0.05).In the case of sufentanil-tramadol PCIA, laparoscopic cholecystectomy needs more postoperative analgesia, while gynecological laparoscopy has higher incidence of dizziness.