Publications by authors named "Xuebin Xu"

102 Publications

Multilocus sequence typing analysis and second-generation sequencing analysis of Salmonella Wandsworth.

J Clin Lab Anal 2021 Jul 10:e23901. Epub 2021 Jul 10.

Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.

Background: Salmonella Wandsworth is a rare serotype of Salmonella. This study analyzed the genotyping, genome structure, and molecular biological functions of Salmonella Wandsworth based on the results of multilocus sequence typing and next-generation sequencing genome assembly analysis.

Methods: Serological typing was performed using the slide-agglutination method. The micro broth dilution method was used to test antibiotic susceptibility. Multilocus sequence typing (MLST) was used to perform the homology analysis, while the second-generation sequencing genome analysis was used to analyze the whole genome of the bacteria.

Results: Salmonella Wandsworth is Group Q Salmonella. The MLST of this strain was ST1498. Salmonella Wandsworth was sensitive to antibiotics, such as ceftriaxone, imipenem, chloramphenicol, and colistin, but was resistant to ampicillin, cefalotin, gentamicin, and ciprofloxacin. The second-generation sequencing results showed that the genome sequence length of the bacteria was 5109457bp. Annotated COG library analysis generated 3,746 corresponding genes. After the comparison with the KEGG library, 1,340 genes, which participate in 19 types of metabolic pathways, were obtained. A total of 249 pathogenic factors and 2 disease islands were predicted. 2 CRISPR sites and 8 Cas sites were predicted. It can be seen from the evolutionary tree that Salmonella Wandsworth MLST1498 and Paratyphi B str.SPB7 are gathered together. We identified one resistance gene, namely, aac(6')-Iaa accounting for aminoglycoside resistance.

Conclusion: Salmonella Wandsworth isolated in this study is Salmonella group Q. Consequently, it is necessary to strengthen the understanding of clinical infections of Salmonella Wandsworth and carry out continuous monitoring and research.
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http://dx.doi.org/10.1002/jcla.23901DOI Listing
July 2021

Prevalence of 16S rRNA Methylation Enzyme Gene in From Outpatients and Food.

Front Microbiol 2021 25;12:663210. Epub 2021 May 25.

State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.

is the primary cause of community-acquired foodborne infections, so its resistance to antimicrobials, such as aminoglycosides, is a public health issue. Of concern, aminoglycoside resistance in is increasing rapidly. Here, we performed a retrospective study evaluating the prevalence of harboring -mediated aminoglycoside resistance in community-acquired infections and in food or environmental sources. The prevalence rates of -harboring strains were 1.1/1,000 (13/12,095) and 8.7/1,000 (32/3,687) in outpatient and food/environmental isolates, respectively. All the -harboring strains were resistant to multiple drugs, including fluoroquinolone and/or extended-spectrum cephalosporins, and most (34/45) belonged to serovar Indiana. The gene of these strains were all carried on plasmids, which spanned five replicon types with IncHI2 being the dominant plasmid type. All the -carrying plasmids were transferable into and recipients. The conjugation experiment results revealed that the -harboring . Indiana strains had a relatively higher ability to acquire -carrying plasmids. The low similarity of their pulsed field gel electrophoresis patterns indicates that the -harboring strains were unlikely to have originated from a single epidemic clone, suggesting broad spread. Furthermore, the genetic backgrounds of -harboring strains isolated from outpatients exhibited higher similarity to those isolated from poultry than to those isolated from swine, suggesting that poultry consumption maybe an infection source. These findings highlight an urgent need to monitor the prevalence and transmission of -harboring , especially Indiana, to better understand the potential public health threat and prevent the further spread of these strains.
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http://dx.doi.org/10.3389/fmicb.2021.663210DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8186500PMC
May 2021

Dissemination of IncFII plasmids carrying fosA3 and bla in clinical isolates of Salmonella enteritidis.

Zoonoses Public Health 2021 Jun 4. Epub 2021 Jun 4.

Department of Food Science & Technology, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China.

Multidrug-resistant Salmonella Enteritidis (S. Enteritidis) isolates have become a significant threat to public health, and fosfomycin has been proposed as one of the therapeutic antibiotics for serious infections by resistant pathogens. In this study, a total of 501 clinical S. Enteritidis isolates were screened and 14 (2.8%) isolates exhibited resistance to fosfomycin (MIC ≥ 1,024 μg/mL) as well as ceftriaxone (MIC ≥ 128 μg/mL). The fosA3 gene was identified in these 14 isolates. The fosA3 gene that co-transferred with bla was observed on the IncFII plasmids with sizes of ~ 78 (n = 7) or ~ 111 (n = 2) kbp in 9 transconjugants. The fosA3-bearing plasmid p12367A is 111,764 bp in length and possessed a typical IncFII backbone. A 7.6-kbp multidrug resistance region (MRR) was identified in p12367A, which was comprised of fosA3 and bla genes interspersed with ΔISEcp1 and three copies of IS26. Two typical antibiotic resistance determinants (IS26-orf3-orf2-orf1-fosA3-IS26 and IS26-orf477-bla -ΔISEcp1-IS26) shared one IS26 in the MRR. The genetic arrangement of the MRR may have resulted from the stepwise integration of IS26 mobile elements via homologous recombination. Horizontal transfer of IncFII plasmids might contribute to the dissemination of fosA3 and bla resistance genes in S. Enteritidis interspecies. These findings underline further challenges for the prevention and treatment of Enterobacteriaceae infections posed by epidemic IncFII plasmids bearing fosA3-bla .
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http://dx.doi.org/10.1111/zph.12825DOI Listing
June 2021

Aetiology of acute diarrhoea in children in Shanghai, 2015-2018.

PLoS One 2021 8;16(4):e0249888. Epub 2021 Apr 8.

Department of Infectious Diseases, Children's Hospital of Fudan University, Shanghai, China.

Diarrhoea remains a major cause of childhood morbidity and mortality worldwide. This study aimed to monitor the aetiology of acute diarrhoea in children in Shanghai. Paediatric outpatients with acute diarrhoea were enrolled in the study from Jan 2015 to Dec 2018. Faecal samples were collected for testing. Enteric bacteria were identified and typed by culture and serotyping, respectively. Enteric viruses were identified by real-time PCR. Enteric pathogens were identified in 1572 (58.4%) of the 2692 enrolled children with acute diarrhoea. Viruses were detected more frequently than bacteria (41.3% versus 25.0%). Nontyphoidal Salmonella spp. (NTS) was the most common (10.3%) bacteria isolated, followed by enteropathogenic Escherichia coli (EPEC) (6.5%), enteroaggregative Escherichia coli (EAEC) (6.2%), Campylobacter spp. (3.6%), enterotoxigenic Escherichia coli (ETEC) (1.1%), Shigella spp. (0.2%), and enterohemorrhagic Escherichia coli (EHEC) (0.1%). Rotavirus was the most common (16.0%) virus detected, followed by norovirus (15.5%), adenovirus (7.2%), sapovirus (3.0%) and astrovirus (2.7%). Rotavirus, norovirus and NTS were the major pathogens responsible for diarrhoea in Shanghainese children. Improving uptake of the rotavirus vaccine and strengthening foodborne-pathogen prevention will aid in reducing the burden of diarrhoeal disease in children in Shanghai.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0249888PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8031434PMC
April 2021

Significantly Enhancing the Lithium Ionic Conductivity of Metal-Organic Frameworks via a Postsynthetic Modification Strategy.

Langmuir 2021 Apr 24;37(13):3922-3928. Epub 2021 Mar 24.

College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China.

Metal-organic frameworks (MOFs), due to their possessing a porous structure, are potential candidates for solid-state ionic conduction materials. Moreover, uncoordinated carboxylic acid groups (-COOH) of MOFs can be used as postsynthetic modification sites, which are favorable for lithium ion exchange. Herein, we synthesized a unique multiple carboxylic zinc metal-organic framework (Zn-MOF-COOH) containing uncoordinated carboxylic acid groups. Zn-MOF-COOLi was synthesized through deprotonation using LiOH via a straightforward acid-base reaction at room temperature (RT), thereby exhibiting better good electrochemical properties. The lithium ionic conductivity (σ) increased from 1.81 × 10 to 1.65 × 10 S·cm, lithium ion transference number () rose from 0.67 to 0.77, and the electrochemical window improved from 2.0-5.5 to 1.5-6.5 V. This work offers a new strategy to improve the σ of MOFs and a new perspective toward manufacturing of high-performance solid-state ionic conduction materials.
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http://dx.doi.org/10.1021/acs.langmuir.1c00156DOI Listing
April 2021

Solvent-Free Synthesis of Iron-Based Metal-Organic Frameworks (MOFs) as Slow-Release Fertilizers.

Polymers (Basel) 2021 Feb 13;13(4). Epub 2021 Feb 13.

The State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science Chinese Academy of Sciences, Nanjing 210008, China.

Metal-organic frameworks (MOFs) were usually synthesized in hydrothermal conditions; in this study, a more energy-saving, easier to control, and solvent-free mechanochemical method was firstly applied to synthesize MOFs with varied reactants as slow release fertilizer, and the components and structures were characterized by X-ray diffraction (XRD), Fourier transform infrared total attenuated reflectance (FTIR-ATR), and laser-induced breakdown spectroscopy (LIBS). Results showed that three MOFs (compounds I, II, and III) were obtained, the MOFs were confirmed as oxalate phosphate oxalate frameworks (OPA-MOF), and ions were adsorbed between layers that contributed to the contents, while urea molecules mainly impacted the structure. The elemental compositions significantly varied among the three compounds; compound I showed the highest content of N (4.91%), P (15.71%), and Fe (18.60%), compound III indicated the highest content of C (6.52%) and K (12.59%), while the contents of C, K, P, and Fe in compound II were in the medium range. Similar release profiles of Fe and P were found among the three MOFs, and the release rates of nutrients were demonstrated as the order of N > K > P > Fe. The compositions and release profiles demonstrated potential application of MOFs as a novel slow-release fertilizer.
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http://dx.doi.org/10.3390/polym13040561DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7918741PMC
February 2021

A valuable strategy to improve ferroelectric performance significantly metallic ion doping in the lattice nodes of metal-organic frameworks.

Chem Commun (Camb) 2021 Mar;57(20):2515-2518

Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot, 010021, P. R. China.

Metal-organic frameworks (MOFs) with polar space groups in crystallography represent a class of potential molecular-based ferroelectrics; however, the rational design and enhancement of the performance of MOF-based ferroelectrics is a great challenge. In this work, a series of mixed-metal MOFs deriving from Mg2+ ions doped into the lattice nodes of the parent-MOF (Ni-MOF) are synthesized by an in situ solvothermal method. Taking advantage of Mg2+ ions doped in the Ni-MOF, the doped-MOFs (Mg/Ni-MOFs) appear to have a significant lattice distortion and noteworthy dipole asymmetry in the crystals. It is found that the obtained doped-MOFs show a significant enhancement of ferroelectricity compared with that of the parent-MOF. This study opens up a new landscape to explore possibilities for controlling ferroelectric performance in MOF-based ferroelectrics.
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http://dx.doi.org/10.1039/d0cc08217aDOI Listing
March 2021

Molecular Characterization of Cephalosporin-Resistant Enteritidis ST11 Isolates Carrying from Children with Diarrhea.

Foodborne Pathog Dis 2021 Feb 2. Epub 2021 Feb 2.

Department of Food Science & Technology, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China.

Enteritidis is an important foodborne pathogen with high prevalence of resistance to cephalosporins, imposing a serious threat to public health. Therefore, a total of 162 Enteritidis isolates collected from child patients in China from 2007 to 2017 were characterized for their resistance to cephalosporins and investigated the transmission characteristics of cephalosporin resistance gene. We found that 15 (9.26%) isolates were all resistant to cefalotin (minimum inhibitory concentration [MIC] ≥512 μg/mL), ceftazidime (MIC 16-128 μg/mL), ceftriaxone (MIC 64 to ≥512 μg/mL), ceftiofur (MIC 64-256 μg/mL), and cefotaxime (MIC 64 to ≥512 μg/mL) with the possession of cephalosporin resistance genes ( = 13), ( = 1), and ( = 1). Molecular typing further revealed that these 15 isolates belonged to sequence type ST11 and shared close pulsed-field gel electrophoresis patterns, suggesting the possibility of clonal spread in Enteritidis interspecies. Furthermore, conjugation experiments were successfully performed in 13 of 15 isolates, and was present on conjugative plasmids with sizes ranging from 54.7 to 173.4 kb. Compared with recipient C600, transconjugants conferred elevated MICs for cephalosporins ranging from 2- to 2048-fold. The genetic structure surrounding of gene in transconjugants were ΔIS-- ( = 8) and IS-- ( = 3), respectively. Taken together, on the plasmids might contribute to cephalosporin resistance in Enteritidis, and conjugative transfer of might facilitate the spread of cephalosporin resistance in Enteritidis. Hence, effective mitigation measurements are needed to reduce the threat caused by cephalosporin-resistant Enteritidis to public health.
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http://dx.doi.org/10.1089/fpd.2020.2878DOI Listing
February 2021

Epidemiology and Characterization of CTX-M-55-Type Extended-Spectrum β-Lactamase-Producing Serovar Enteritidis Isolated from Patients in Shanghai, China.

Microorganisms 2021 Jan 27;9(2). Epub 2021 Jan 27.

College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China.

The emergence of extended-spectrum β-lactamase-producing serovar Enteritidis (ESBL-SE) in humans and foods has gained global attention. In particular, CTX-M-type ESBL-SE are increasingly being detected from various sample types. The aim of this study was to comprehensively analyze the epidemiology and characteristics of -carrying ESBL-SE isolates of clinical origin in Shanghai, China. A total of 292 Enteritidis isolates were recovered from the feces and blood of outpatients and inpatients between 2006 and 2014. Overall, there was a high frequency of cefotaxime-resistant isolates (97.3%), which was significantly higher ( < 0.01) than that of isolates resistant to the other tested antibiotics. All Enteritidis isolates exhibited resistance to ≥1 antibiotic, and 98.0% were multidrug resistant. A total of 233 isolates were identified as ESBL-SE, 166 of which were CTX-M type. Six subtypes of CTX-M-encoding genes were detected, among which (91.6%, 152/166) was the most prevalent genotype. There was high genetic similarity among -positive ESBL-SE. The gene in the ESBL-SE donor strains could be easily transferred into recipient strains. This study highlights that CTX-M-55 should be considered an important surveillance target in Shanghai, China. Cephalosporins, especially cefotaxime, must be used with caution in empirical treatment for infections.
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http://dx.doi.org/10.3390/microorganisms9020260DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7912593PMC
January 2021

Fabrication of a "turn-on"-type enantioselective fluorescence sensor via a modified achiral MOF: applications for synchronous detection of phenylalaninol enantiomers.

Analyst 2021 Feb 26;146(3):937-942. Epub 2020 Nov 26.

Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot, 010021, China.

Homochiral metal-organic frameworks (HMOFs) have garnered considerable attention due to their extrachiral properties and broad application for chiral recognition. However, assembling a pair of high-quality chiral MOFs for sensing enantiomers precisely is a formidable challenge because of the complicated chiral environment and uncontrollable coordinated conditions. Herein, one pair of homochiral UiO-66 analogues, S-1 ([email protected](COOH)) and R-1 ([email protected](COOH)), are reported for chiral recognition. They were fabricated via a condensation reaction between the carboxyl groups of UiO-66-(COOH) and amino groups of l/d-amino propanol (l/d-AP). These novel fluorescent probes exhibited highly enantioselective fluorescence enhancement towards l/d-phenylalaninol (l/d-PA). For example, when S-1 and R-1 were treated with l-PA or d-PA, they displayed different fluorescence responses: the enantiomeric fluorescence enhancement ratio (ef) was 2.51 and 0.41 for S-1 and R-1, respectively. Hence, a visible difference in fluorescence enhancement for l-PA and d-PA and excellent enantioselective behavior between S-1 and l-PA (or R-1 and d-PA) was displayed. Measurements of fluorescence lifetime, powder X-ray diffraction, molecular-dynamic simulations and Benesi-Hildebrand plots were employed to determine the observed high enantioselectivity for l/d-PA. In brief, we found that two post-modified HMOFs, S-1 and R-1, were outstanding enantioselective sensors for detecting l-PA and d-PA. They had a prominent difference in ef and remarkable enantioselectivity factor α and ΔΔG based on steric hindrance and stereochemical difference.
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http://dx.doi.org/10.1039/d0an01879aDOI Listing
February 2021

Co-occurrence of mcr-9, extended spectrum β-lactamase (ESBL) and AmpC genes in a conjugative IncHI2A plasmid from a multidrug-resistant clinical isolate of Salmonella diarizonae.

J Infect 2021 04 11;82(4):84-123. Epub 2020 Nov 11.

State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China. Electronic address:

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http://dx.doi.org/10.1016/j.jinf.2020.11.008DOI Listing
April 2021

The Evaluation of the Multiple Myeloma Pathological Osseous Tissue of Microarchitecture.

Curr Med Imaging 2021 ;17(4):513-516

Human Anatomy Teaching and Research Section (Digital Medical Center), Inner Mongolia Medical University Basic Medical College, Hohhot, 010059, China.

Background: The typical imaging finding of MM is bone destruction in the form of diffuse patchy osteolytic lesions or punctate destruction. However, it is difficult to accurately determine the fine structure of bone affected by MM with these techniques due to low specificity and sensitivity.

Introduction: This study aimed to investigate the microscopic anatomical morphology and analyze the microstructure changes of trabeculae affected by multiple myeloma (MM) based on micro-CT.

Methods: MM-affected and normal trabecular bone samples were imaged by micro-CT to obtain bone structure parameters to assess statistical differences between them and evaluate the degree of microstructural damage of MM-affected trabeculae.

Results: Micro CT images clearly showed the microstructure of MM-affected trabeculae. The degree of trabecular osteoporosis varied with the severity of MM. There were significant differences in the structural parameters between MM-affected and normal trabeculae (P < 0.05).

Conclusion: Micro-CT clearly reveals the microstructure of MM-affected trabeculae. The obtained bone structure data will help to determine the degree of bone damage caused by MM and assess the efficacy.
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http://dx.doi.org/10.2174/1573405616666201015144015DOI Listing
January 2021

Characterization of Multidrug Resistance Patterns of Emerging Serovar Rissen along the Food Chain in China.

Antibiotics (Basel) 2020 Sep 30;9(10). Epub 2020 Sep 30.

Institute of Veterinary Sciences & Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.

spp. are recognized as important foodborne pathogens globally. serovar Rissen is one of the important serovars linked with swine products in numerous countries and can transmit to humans by food chain contamination. Worldwide emerging . Rissen is considered as one of the most common pathogens to cause human salmonellosis. The objective of this study was to determine the antimicrobial resistance properties and patterns of Rissen isolates obtained from humans, animals, animal-derived food products, and the environment in China. Between 2016 and 2019, a total of 311 Rissen isolates from different provinces or province-level cities in China were included here. Bacterial isolates were characterized by serotyping and antimicrobial susceptibility testing. Minimum inhibitory concentration (MIC) values of 14 clinically relevant antimicrobials were obtained by broth microdilution method. . Rissen isolates from humans were found dominant (67%; 208/311). . Rissen isolates obtained from human patients were mostly found with diarrhea. Other . Rissen isolates were acquired from food (22%; 69/311), animals (8%; 25/311), and the environment (3%; 9/311). Most of the isolates were resistant to tetracycline, trimethoprim-sulfamethoxazole, chloramphenicol, streptomycin, s ceftriaxone, c ciprofloxacin, and azithromycin. In total, 92% of the . Rissen isolates were multidrug-resistant and ASSuT (27%), ACT (25%), ACSSuT (22%), ACSSuTAmc (11%), and ACSSuTFox (7%) patterns were among the most prevalent antibiotic resistance patterns found in this study. The widespread dissemination of antimicrobial resistance could have emerged from misuse of antimicrobial agents in animal husbandry in China. These findings could be useful for rational antimicrobial usage against Rissen infections.
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http://dx.doi.org/10.3390/antibiotics9100660DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7600917PMC
September 2020

Discovery of mcr-3.1 gene carried by a prophage located in a conjugative IncA/C2 plasmid from a Salmonella Choleraesuis clinical isolate.

J Infect 2021 03 30;82(3):414-451. Epub 2020 Sep 30.

State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China. Electronic address:

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http://dx.doi.org/10.1016/j.jinf.2020.09.036DOI Listing
March 2021

Antimicrobial resistance and molecular characterization of Salmonella enterica serovar Corvallis isolated from human patients and animal source foods in China.

Int J Food Microbiol 2020 Dec 8;335:108859. Epub 2020 Sep 8.

National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Lingnan Guangdong Laboratory of Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China. Electronic address:

In this study, 205 Salmonella enterica serovar Corvallis strains were obtained from humans and foods from Guangdong, Guangxi, and Shanghai in China from 2009 to 2017 to assess drug resistance and molecular epidemiology. These isolates displayed high rates of resistance to sulfisoxazole (94.15%) and tetracycline (77.56%). Surprisingly, the rate of resistance to ciprofloxacin reached 21.46%. Moreover, 63.9% of the strains displayed multidrug resistance. Detection of quinolone genes showed that 97.56% of the strains had single mutations (T57S) in parC. The plasmid-mediated quinolone resistance (PMQR) genes qnrS, aac(6')-Ib-cr, and qnrB, were also detected. The extended spectrum β-lactamase (ESBLS) gene that was most common among the isolates was bla (18.05%). These S. Corvallis isolates are the first to date, that have been reported to possess bla or bla. Additionally, 95.61% of isolates were biofilm producers. The streptomycin resistance rate was higher in strong biofilm producers (87.50%) than in moderate (37.93%) and weak (26.49%) biofilm producers. Pulsed-field gel electrophoresis (PFGE) showed that some strains from different sources had the same genotype. These isolates may be transmitted to humans through food and therefore the monitoring of these isolates should be strengthened in China.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2020.108859DOI Listing
December 2020

A new plasmid carrying mphA causes prevalence of azithromycin resistance in enterotoxigenic Escherichia coli serogroup O6.

BMC Microbiol 2020 08 11;20(1):247. Epub 2020 Aug 11.

Academy of Military Medical Sciences, NO.20 Dongda Street, Fengtai District, Beijing, 100071, China.

Background: At present, azithromycin has become an effective treatment for severe diarrhea caused by Enterotoxigenic Escherichia coli (ETEC) infection. However, enterobacteria have begun to develop resistance to azithromycin and have attracted attention in recent years. This study conducted to described the emergence of a high proportion of azithromycin-resistant ETEC serogroup O6 strains in Shanghai and to analyzed the mechanisms of azithromycin resistance.

Results: Strains from adult diarrhea patients with ETEC serogroup O6 infections were collected by Shanghai Diarrhea Surveillance Network and the Foodborne Surveillance Network from 2016 to 2018. We tested 30 isolates of ETEC O6 serogroup, 26 of which were resistant to azithromycin. Phylogenetic analysis revealed that these ETEC serogroup O6 strains have formed an independent dominant clone. S1-PFGE and southern blotting revealed the presence of the mphA gene on the 103 kb plasmid. Illumina and Nanopore sequencing and plasmid coverage analysis further confirmed that azithromycin-resistant strains carried a novel IncFII plasmid harboring mphA and blaTEM-1 resistance genes.

Conclusions: This is the first study to report a high proportion of azithromycin resistance in a particular ETEC serogroup due to a specific plasmid carrying mphA. Our findings indicate the rapid spread of azithromycin resistance, highlighting the urgency of stringent surveillance and control measure.
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http://dx.doi.org/10.1186/s12866-020-01927-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418381PMC
August 2020

An unusual high-frequency ferroelectric obtained via the post-synthetic modification of a metal-organic framework.

Dalton Trans 2020 Aug;49(31):10895-10900

Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P.R. China.

Ferroelectrics as crucial functional materials have attracted much interest since ferroelectricity was discovered in 1920. Herein, an unusual high-frequency ferroelectric, (CH3)2NH·[email protected], was successfully obtained through a dual-step synthetic methodology. A chiral porous Cd-MOF with a channel size of 6.8 × 6.8 Å was synthesized via self-assembly of chiral Schiff-base ligands and Cd2+ ions. Subsequently, polarizable (CH3)2NH·HCl was introduced into the channels of the Cd-MOF and hence the host-guest system (CH3)2NH·[email protected] was formed. The as-synthesized (CH3)2NH·[email protected] displays obvious ferroelectricity at a high frequency of 1 kHz. Such a high-frequency ferroelectric is extremely rare among MOF-based ferroelectric materials, and the high-frequency ferroelectricity means that (CH3)2NH·[email protected] has potential for use in ferroelectric memories. The results again demonstrate that post-synthetic modification is a promising approach for achieving rational and precise design of ferroelectric materials.
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http://dx.doi.org/10.1039/d0dt02066dDOI Listing
August 2020

Characterization of Oxacillin-Susceptible -Positive from Food Poisoning Outbreaks and Retail Foods in China.

Foodborne Pathog Dis 2020 11 21;17(11):728-734. Epub 2020 Jul 21.

College of Food Science and Engineering, Northwest A&F University, Yangling, China.

In this study, we explored the prevalence of oxacillin-susceptible -positive (OS-MRSA) in staphylococcal food poisoning outbreak isolates and foodborne isolates, and then investigated their molecular characteristics, classical staphylococcal enterotoxins (SEs), and drug resistance. Eight (2.9%) of 275 isolates from food poisoning outbreaks and 7 (3.8%) of 184 isolates from retail foods were identified as OS-MRSA isolates. Among the 15 OS-MRSA isolates, the most frequently detected toxin genes were (100%), (93.3%), (80.0%), and (46.7%) followed by and (33.3%, each), (26.7%), and (20.0%, each), , , , , and (13.3%, each), and , , , and (6.7%, each). None of isolates carried other tested virulence genes. The most frequently detected classical SEs were SEB and SEC (26.7%, each), followed by SEA and SEE (20.0%, each), and SED (6.7%). Resistance was most frequently observed in ampicillin, penicillin, and cefoxitin (100%, each), followed by trimethoprim/sulfamethoxazole (93.3%), erythromycin (73.3%), amoxicillin/clavulanic acid (46.7%), tetracyclines (26.7%), and ciprofloxacin (6.7%). All isolates were susceptible to other tested antibiotics. A dominant molecular type belonged to ST398-IVa-t034 (26.7%), followed by ST59-IVa-t437 (20.0%), ST88-III-t14340 and ST1-IVa-t114 (13.3%, each), and ST5-II-t002, ST630-t4549, ST5-II, and ST4495-t10738 (6.7%, each). Our findings indicated that OS-MRSA strains had a low prevalence rate among outbreak strains and foodborne strains, which frequently harbored SCCmec IVa, and carried a variety of toxin genes, and also expressed numerous classical SEs. In addition, all OS-MRSA isolates were susceptible to the majority of antibacterial agents except -lactam. Our study is the first to report that OS-MRSA isolates are associated with food poisoning outbreaks worldwide.
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http://dx.doi.org/10.1089/fpd.2019.2774DOI Listing
November 2020

Crystal structures and the ferroelectric properties of homochiral metal-organic frameworks constructed from a single chiral ligand.

Dalton Trans 2020 Aug 14;49(30):10402-10406. Epub 2020 Jul 14.

Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P.R. China.

MOFs have proven to be promising candidates for designing ferroelectric materials. Herein, two new homochiral MOFs, Co-MOF-1 and Co-MOF-2, have been synthesized using the chiral ligand, HL (HL = phenyl-((pyridin-4-ylmethyl)-amino)-acetic acid), and Co(NO)·6HO. Co-MOF-1 was obtained via a two-step synthetic route involving a hydrogel to Zn-MOF conversion and a dissolution-recrystallization process. Co-MOF-2 was directly synthesized by a coordination reaction between chiral ligand, HL, and Co(NO)·6HO under hydrothermal conditions. We investigate the correlation between the ferroelectric properties of the samples and their crystal structures. The ferroelectric properties of Co-MOF-1 and Co-MOF-2 are drastically different. Indeed, Co-MOF-2 shows an obvious hysteretic behavior, while a clear electric hysteresis loop was not observed for Co-MOF-1. These significant disparities may be attributed to the different molecular dipole moments in Co-MOF-1 and Co-MOF-2. The different octahedral coordination units in the molecular structures of the Co-MOFs may alter the dipole moments of the molecules, resulting in the absence of a hysteresis loop for Co-MOF-1.
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http://dx.doi.org/10.1039/d0dt01323dDOI Listing
August 2020

Genomic analyses of multidrug-resistant Salmonella Indiana, Typhimurium, and Enteritidis isolates using MinION and MiSeq sequencing technologies.

PLoS One 2020 2;15(7):e0235641. Epub 2020 Jul 2.

Joint Institute for Food Safety and Applied Nutrition, Center for Food Safety and Security Systems, University of Maryland, College Park, Maryland, United States of Amrica.

We sequenced 25 isolates of phenotypically multidrug-resistant Salmonella Indiana (n = 11), Typhimurium (n = 8), and Enteritidis (n = 6) using both MinION long-read [SQK-LSK109 and flow cell (R9.4.1)] and MiSeq short-read (Nextera XT and MiSeq Reagent Kit v2) sequencing technologies to determine the advantages of each approach in terms of the characteristics of genome structure, antimicrobial resistance (AMR), virulence potential, whole-genome phylogeny, and pan-genome. The MinION reads were base-called in real-time using MinKnow 3.4.8 integrated with Guppy 3.0.7. The long-read-only assembly, Illumina-only assembly, and hybrid assembly pipelines of Unicycler 0.4.8 were used to generate the MinION, MiSeq, and hybrid assemblies, respectively. The MinION assemblies were highly contiguous compared to the MiSeq assemblies but lacked accuracy, a deficiency that was mitigated by adding the MiSeq short reads through the Unicycler hybrid assembly which corrected erroneous single nucleotide polymorphisms (SNPs). The MinION assemblies provided similar predictions of AMR and virulence potential compared to the MiSeq and hybrid assemblies, although they produced more total false negatives of AMR genotypes, primarily due to failure in identifying tetracycline resistance genes in 11 of the 19 MinION assemblies of tetracycline-resistant isolates. The MinION assemblies displayed a large genetic distance from their corresponding MiSeq and hybrid assemblies on the whole-genome phylogenetic tree, indicating that the lower read accuracy of MinION sequencing caused incorrect clustering. The pan-genome of the MinION assemblies contained significantly more accessory genes and less core genes compared to the MiSeq and hybrid assemblies, suggesting that although these assemblies were more contiguous, their sequencing errors reduced accurate genome annotations. Our research demonstrates that MinION sequencing by itself provides an efficient assessment of the genome structure, antimicrobial resistance, and virulence potential of Salmonella; however, it is not sufficient for whole-genome phylogenetic and pan-genome analyses. MinION in combination with MiSeq facilitated the most accurate genomic analyses.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235641PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7332006PMC
September 2020

Genomic characterization of Uzaramo for human invasive infection.

Microb Genom 2020 07;6(7)

Zhejiang Provincial Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, PR China.

is composed of a wide variety of serovars, causing human self-limited gastrointestinal illnesses or invasive infections. Invasive non-typhoidal (iNTS) is well documented, with high mortality for children and immunocompromised adults in sub-Saharan Africa and has recently been reported in Southeast Asia. However, iNTS in China remains unknown. In May 2019, a case of invasive infection caused by serovar Uzaramo (. Uzaramo) was reported for the first time in China. Phylogenomic analysis was performed by genomic sequencing the available contextualized isolates, which separated the two Chinese strains into different sublineages. Both phenotypic and genomic characterization demonstrated that the . Uzaramo isolates showed in general low antimicrobial resistance potential, except one isolated from lake-water in China. Additional comparative genomic analysis and killing assays suggested a unique combination of virulence factors, including typhoid toxin and fimbrial adhesin, which might play a role in the invasive infection. This study highlights that the transparency of global surveillance genomic data could accelerate understanding of virulence and antimicrobial resistance makeup of a previously unknown threat.
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http://dx.doi.org/10.1099/mgen.0.000401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7478631PMC
July 2020

Plasmid-Encoded Gene That Confers High-Level Carbapenem Resistance in Typhimurium of Pork Origin.

Infect Drug Resist 2020 19;13:1485-1490. Epub 2020 May 19.

National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangdong Laboratory for Lingnan Modern Agriculture, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Animal Vaccine Development, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, People's Republic of China.

Purpose: Carbapenem resistance is rarely reported in Typhimurium, especially from a food origin. Here, we report a plasmid-mediated mobile carbapenem-resistant gene in Typhimurium isolated from pork in Shanghai, China in 2016.

Patients And Methods: In July 2016, the . Typhimurium SH160 strain was recovered from minced pork meat purchased from a supermarket in Yangpu District, Shanghai, China. Antimicrobial susceptibility testing, multi-locus sequence typing, conjugation, S1-PFGE, southern hybridization, whole-genome sequencing and data analysis were performed.

Results: This isolate was found to be a ST34 strain and resistant to carbapenems, cephalosporins, and most other commonly used antibiotics. The gene was harbored by a 46161-bp IncX3 plasmid which was found to be transferable. The IncX3 plasmid contains a composite cassette, consisting of . In addition, this strain was found to harbor an additional 161706-bp IncHI2 plasmid which carries nine resistant genes, such as and .

Conclusion: We reported the Typhimurium with transferable IncX3 plasmid harboring gene from minced pork. We characterized the complete genetic features of the plasmid, which demonstrated the potential for spreading in different bacterial pathogens. Therefore, extensive surveillance and monitoring for carbapenem-resistant bacterium in the food chain and public health are urgently required.
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http://dx.doi.org/10.2147/IDR.S249357DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7250698PMC
May 2020

Fourth Generation Cephalosporin Resistance Among Serovar Enteritidis Isolates in Shanghai, China Conferred by Harboring Plasmids.

Front Microbiol 2020 15;11:910. Epub 2020 May 15.

National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangdong Laboratory for Lingnan Modern Agriculture, Laboratory of Veterinary Vaccine Innovation of the Ministry of Agriculture, Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.

In this study, we investigated the pattern of antimicrobial resistance in enterica serotype Enteritidis isolates in Shanghai, China from 2005 to 2014. We found the first isolates with resistance to the fourth-generation cephalosporin cefepime starting in 2010. Furthermore, we analyzed the epidemic characteristics and mechanisms of underlying cefepime resistance in Enteritidis isolates found from 2010. In total, 38 of 2,914 (1.30%) isolates were identified as cefepime-resistant Enteritidis (CRSE) isolates by Kirby-Bauer disk diffusion. Two isolates were from animal derived food sources; 36 isolates were from fecal samples of human patients with salmonellosis. Antimicrobial susceptibility testing using the agar dilution method revealed that all CRSE isolates showed additional resistances at least to ceftazidime, cefotaxime, and ampicillin. Additionally, pulsed-field gel electrophoresis (PFGE) profiles indicated that 89.47% of CRSE isolates also displayed similar PFGE patterns. Five types of β-lactamase genes, (100.00%, 38/38), (65.79%, 25/38), (52.63%, 20/38), (18.42%, 7/38), and (5.26%, 2/38) were detected by PCR and sequencing. Among genes, was the dominant type (84.21%, 32/38). Conjugation and transformation experiments along with plasmid replicon typing revealed that was located on plasmids of various replicon types with sizes ranging from 76.8 to 138.9 kb. Plasmid sequence analysis also showed that the gene was mobilized mainly by the IS- -ORF477 transposition unit and had its own IS-based promoter, which accelerated the expression and transmission of . Analysis of whole genome sequences (Illumina) of one selected transformant SH12G706-C showed high similarity of the carrying plasmid with the IncI1 plasmid backbone p628-CTX-M of detected in 2010 in China. The present study demonstrated that the gene mobilized by IS- -ORF477 was the main feature shared by CRSE isolates and seems to play an important role for transmission of cefepime resistance. The number of CRSE isolates is rising annually, and the strong dissemination ability of IS- -ORF477-harboring plasmids among different species represents an important threat to the therapeutic effectiveness of cefepime.
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http://dx.doi.org/10.3389/fmicb.2020.00910DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7242564PMC
May 2020

Persistent Asymptomatic Human Infections by Salmonella enterica Serovar Newport in China.

mSphere 2020 05 27;5(3). Epub 2020 May 27.

CATG Microbiology & Food Safety Laboratory, Institute of Preventive Veterinary Science & Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou, China

serovar Newport ( Newport) infections are gradually on the rise in China from the last decade. For humans' infections, Newport has been ranked among the top five serovars responsible for persistent infections, globally. A total of 290 Newport strains with their relevant clinical metadata were analyzed, and the strains were subjected to whole-genome sequence analysis. Among these, 62.4% ( = 181) were from diarrheic patients and 28.9% ( = 84) were from asymptomatic individuals (including adults and youngsters) while 8.6% ( = 25) were from cases of persistent diarrhea in infants (28%,  = 7) and toddlers (72%,  = 18). The association between the sequence types (STs) and the variations in the clinical presentation was statistically significant (0.0432), with ST46 causing diarrhea or representing asymptomatic patients and ST31 or ST68 causing persistent diarrhea. Genomic analysis revealed that the highest proportion of the isolates (98.5%,  = 279), primarily from patients with or without diarrhea rather than from asymptomatic individuals, carried antimicrobial resistance determinants corresponding to the aminoglycosides and beta-lactams, highlighting the need for cautionary usage of antimicrobials in such patients. These findings also suggest that cases of nontyphoidal infection with symptoms of acute diarrhea or persistent diarrhea caused by Newport should be handled with caution, due to the high chance of development of an antimicrobial resistance phenotype that might lead to therapeutic failures. Together, Newport ST31 and ST46, which have the highest frequency of carriage of multidrug resistance, are potentially responsible for antimicrobial-resistant diarrhea/persistent diarrhea in infants and children, while adult humans are more likely to be (asymptomatic) carriers of the Newport strains. Human infections caused by Newport generally lead to gastrointestinal diseases. These infections are normally self-limiting; however, in certain cases, broad-spectrum antimicrobials are prescribed for the treatment. The Chinese National Foodborne Disease Surveillance Network has reported a gradual increase in the incidence of multidrug-resistant Newport infections in humans. After careful evaluation of the dynamic relationship among the clinical findings, the age group, and the genomic sequence data, it was found that young patients represented the major group with persistent diarrhea, whereas adults were either asymptomatic or diarrheic. Furthermore, all these strains contained multiple acquired antimicrobial resistance determinants, which limited the use of antimicrobials for human patients of all age groups. This analysis of the laboratory-confirmed cases, coupled with genetic analysis of the corresponding pathogen, revealed that antimicrobial treatment of persistent infections by Newport in infants and toddlers, and in asymptomatic or diarrheic adults, may not be successful. If the antimicrobials must be prescribed at all, they must be used with caution because of the presence of multiple acquired antimicrobial resistance determinants in such strains.
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http://dx.doi.org/10.1128/mSphere.00163-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7253594PMC
May 2020

Investigation of a Salmonellosis Outbreak Caused by Multidrug Resistant Typhimurium in China.

Front Microbiol 2020 29;11:801. Epub 2020 Apr 29.

Academy of Military Medical Sciences, Beijing, China.

The rapid emergence of multidrug resistant is a global public-health concern as outbreaks in recent years have mostly been caused by multidrug resistant strains. Here, we evaluated an outbreak in China caused by multidrug resistant serovar Typhimurium (. Typhimurium) by employing an epidemiological and laboratory investigation using conventional methods and whole genome sequencing (WGS). Eleven of the 12 people who participated in a banquet showed gastrointestinal symptoms, and 8. Typhimurium strains were recovered. Isolated outbreak strains showed multidrug resistance (MDR), and decreased susceptibility to ciprofloxacin, a first-line drug recommended by WHO for clinical treatment of intestinal infections. Antimicrobial resistance (AMR) gene analysis indicated that the MDR phenotype of these outbreak strains may be due to the presence of a number of AMR genes, including the OXA-1 and TEM-1 β-lactamase genes, which are often plasmid-borne and easily transferred. Further virulence gene analysis indicated that these outbreak strains also carried a large number of virulence genes, including 2 types of pathogenicity islands (SPI-1 and SPI-2) and many adhesion-related virulence genes. Cluster analysis based on pulse-field gel electrophoresis data and phylogenetic analysis based on WGS revealed that the outbreak clone was closely related to and thus probably derived from local strains. This outbreak caused by multidrug resistant Typhimurium highlights the need for government improved strategies for the prevention and control of infections.
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http://dx.doi.org/10.3389/fmicb.2020.00801DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7200987PMC
April 2020

Magnetic Ring Multi-Defect Stereo Detection System Based on Multi-Camera Vision Technology.

Sensors (Basel) 2020 Jan 10;20(2). Epub 2020 Jan 10.

Guangdong Xi'an Jiaotong University Academy, Foshan 528000, China.

Magnetic rings are the most widely used magnetic material product in industry. The existing manual defect detection method for magnetic rings has high cost, low efficiency and low precision. To address this issue, a magnetic ring multi-defect stereo detection system based on multi-camera vision technology is developed to complete the automatic inspection of magnetic rings. The system can detect surface defects and measure ring height simultaneously. Two image processing algorithms are proposed, namely, the image edge removal algorithm (IERA) and magnetic ring location algorithm (MRLA), separately. On the basis of these two algorithms, connected domain filtering methods for crack, fiber and large-area defects are established to complete defect inspection. This system achieves a recognition rate of 100% for defects such as crack, adhesion, hanger adhesion and pitting. Furthermore, the recognition rate for fiber and foreign matter defects attains 92.5% and 91.5%, respectively. The detection speed exceeds 120 magnetic rings per minutes, and the precision is within 0.05 mm. Both precision and speed meet the requirements of real-time quality inspection in actual production.
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http://dx.doi.org/10.3390/s20020392DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014282PMC
January 2020

Forensic soil analysis using laser-induced breakdown spectroscopy (LIBS) and Fourier transform infrared total attenuated reflectance spectroscopy (FTIR-ATR): Principles and case studies.

Forensic Sci Int 2020 May 28;310:110222. Epub 2020 Feb 28.

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.

Soils are crucial trace evidence that can establish or exclude the relationship between a suspect, victim, or an object at a particular scene, which could contribute to building a case. Laser-induced breakdown spectroscopy (LIBS) and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy have been demonstrated to be effective techniques for soil characterization owing to its being rapid, non-destructive, and convenient analysis with little sample preparation requirements. Therefore, the principles of LIBS and FTIR-ATR techniques for soil forensic analysis in typical soil samples were investigated and their practical feasibility was tested by applying the techniques to forensic soil samples in two criminal cases. Principal component analysis (PCA) of a typical soil sample indicated that five typical soil types were clearly distinguished by LIBS and FTIR-ATR spectra. Variations in the soil elements (i.e., Si, Mg, Al, Ca, K, O, and N) and functional groups (i.e., OH/NH, CC/CO, SiO, CO, AlOH, and NH) are crucial indicators for soil identification. The casework results demonstrated that both LIBS and FTIR-ATR show great potential for forensic soil analysis in future cases.
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http://dx.doi.org/10.1016/j.forsciint.2020.110222DOI Listing
May 2020

Presence of heavy metal resistance genes in Escherichia coli and Salmonella isolates and analysis of resistance gene structure in E. coli E308.

J Glob Antimicrob Resist 2020 06 30;21:420-426. Epub 2020 Jan 30.

College of Resources, Sichuan Agricultural University, Chengdu 611130, Sichuan, PR China. Electronic address:

Objectives: With the wide use of heavy metals as feed additives in animal production, little attention has been paid to heavy metal resistance in pathogenic bacteria. This study was performed to investigate the presence of heavy metal resistance genes (HMRGs) in Escherichia coli and Salmonella isolates and its correlation with disinfectant resistance genes (DRGs) and antibiotic resistance genes (ARGs).

Methods: HMRGs of 178 E. coli and 294 Salmonella isolated from chicken broiler farms and retail meat were detected by PCR. Minimum inhibitory concentrations (MICs) of heavy metals were determined by the broth microdilution method. The complete genome of E. coli E308, which had indications of multidrug resistance, was recovered and assembled using third-generation sequencing.

Results: The frequency of different HMRGs in E. coli and Salmonella ranged from 0.60-77.0% and 0.30-87.1%, respectively. MICs of heavy metals for E. coli and Salmonella ranged widely from ≤12.5 mg/L to 1600 mg/L. Moreover, HMRGs (zntA, arsB, merA, pcoR, pcoA, pcoC and chrA) were found to be significantly associated with one or more DRGs [sugE(c), emrE, mdfA, ydgE/ydgF, qacF, sugE(p) and qacEΔ1] and ARGs (sul1, sul2, sul3, tetA, tetB, tetC, bla, bla and bla) (P < 0.05).

Conclusion: This study demonstrated that HMRGs are widely present in E. coli and Salmonella isolated from chicken farms and retail meat. The association between HMRGs with DRGs and ARGs may lead to co-resistance to heavy metals and other antimicrobial agents.
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http://dx.doi.org/10.1016/j.jgar.2020.01.009DOI Listing
June 2020

A multi-stimuli-responsive metallohydrogel applied in chiral recognition, adsorption of poisonous anions, and construction of various chiral metal-organic frameworks.

Chem Commun (Camb) 2019 Dec 8;55(94):14178-14181. Epub 2019 Nov 8.

Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, China.

The design of stimuli-responsive hydrogels is attractive but challenging. A multi-stimuli-responsive chiral metallohydrogel was constructed using a rational approach to design a functional metallohydrogel using chiral organic gelators. The as-synthesized metallohydrogel reported here performed remarkably as a visual sensor for discriminating between (R)-phenylglycinol and (S)-phenylglycinol. Furthermore, the metallohydrogel showed a significant capacity for adsorption and enrichment of Cr(vi) in aqueous solution. Besides this, by utilizing anion-induced transformation, the metallohydrogel could be controllably directed to synthesize different types of chiral metal-organic frameworks.
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http://dx.doi.org/10.1039/c9cc07621bDOI Listing
December 2019

Rapid Emergence of Florfenicol-Resistant Invasive Non-Typhoidal in China: A Potential Threat to Public Health.

Am J Trop Med Hyg 2019 12;101(6):1282-1285

National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Key Laboratory of Zoonoses, Ministry of Agriculture, Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Animal Infectious Diseases Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.

Infection caused by invasive occurs when bacteria, which normally cause diarrhea, enter the bloodstream and spread through the body. We report the dramatic increase in florfenicol-resistant invasive non-typhoidal (iNTS) in China between 2007 and 2016. Of the 186 iNTS strains isolated during the study period, 34 were florfenicol resistant, most of which harbored known resistance genes. Florfenicol is exclusively used in veterinary medicine in China, but now florfenicol-resistant iNTS is found in clinical patients. This finding indicates that antimicrobial resistance produced in veterinary medicine can be transmitted to humans, which poses a severe threat to public health.
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http://dx.doi.org/10.4269/ajtmh.19-0403DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6896861PMC
December 2019