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•We describe a strain of S. Typhimurium resistant to 28 antibiotics.•The strain carried 54 AMR genes, and blaOKP-B-10was found in Salmonellafirst.•The strain carried two novel plasmids.•pSH11G993-1 carried 14 AMR genes, including blaCMY-2, mphA, and ermB.•pSH11G993-2 endowed the strain virulence and resistance.

•Of the faecal samples obtained from clinical settings in Shanghai, 3.9% were mcr-1-positive Escherichia colistrains.•All mcr-1was detected in four types of E. coli, including atypical enteropathogenic E. coli(aEPEC), enteropathogenic E. coli(EPEC), enterotoxigenic E. coli(ETEC), and enteroaggregative E. coli(EAEC).•Half of the strains carrying quinolone resistance- or β-lactam resistance-related genes were multidrug-resistant.•IncX4 was the predominant type in mcr-1-positive E. coli.

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.

Soil organic matter (SOM) significantly influences soil fertility, biology, and the global C cycle. Laser‐induced breakdown spectroscopy (LIBS) is attractive, as it can measure SOM accurately and quickly with minimal sample preparation and effective cost. Our earlier self‐adaptive (SA) model based on individual distances between LIBS soil spectra coupled with partial least squares (PLS) was favorable for SOM prediction. To optimize this model by including soil identification via the use of a hybrid distance between the spectra, two hybrid distance SA models to enhance SOM predictions from LIBS spectra in 250 Chinese topsoils were built and studied. The models used LIBS soil spectra and SOM content measured by the traditional potassium dichromate oxidation method for calibration. The performance of these models for the validation set was compared with the conventional no‐identification PLS model and SA‐PLS models. The modified models that used (a) a hybrid of Euclidean distance (ED) and angle cosine (SAxc–PLS), and (b) a hybrid of ED and the distance of response y(SAxy–PLS) improved SOM predictions , with a R2of 0.908, a RMSE of 5.65 g kg−1, and a residual prediction deviation (RPD) of 2.91 in the validation set for SAxc–PLS; and a R2of 0.900, a RMSE of 5.49 g kg−1, and a RPD of 2.99 in the validation set for SAxy–PLS. The improved performance mainly resulted from simultaneous consideration of diversity and correlation of the spectra. Therefore, modified SA models hold great potential for SOM prediction, especially for different soils.

In this study, we explored the prevalence of oxacillin-susceptible mecA-positive Staphylococcus aureus(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 hld(100%), hla(93.3%), pvl(80.0%), and hlb(46.7%) followed by segand seq(33.3%, each), hlg(26.7%), seband hlgv(20.0%, each), sec, seh, sel, sep, and tst(13.3%, each), and sei, sem, sen, and seo(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 β-lactam. Our study is the first to report that OS-MRSA isolates are associated with food poisoning outbreaks worldwide.

Laser‐induced breakdown spectroscopy (LIBS) is an emerging multi‐elemental analytical technique offering fast and simultaneous quantification of soil properties with minimal sample preparation and effective cost. Due to soil heterogeneity, spectral variation however limits the quantitative robustness. In this study, 348 soil samples were collected and prepared for acquisition of LIBS spectra. Influences of shot layer and number on LIBS quality were evaluated by spectral intensity and relative standard deviation (RSD). Effects of shot layer and number and five normalization procedures on LIBS ability to measure soil organic matter (SOM), total nitrogen (TN), and total soluble salt content (TSC), were evaluated using partial least squares regression (PLSR). Increasing shot number reduced LIBS spectral variance, thereby improving the quantitative accuracy of selected soil properties. Deep shot layers (4th or 5th shot layers) reduced the intensities of soil spectra and thereby decreased the quantitative accuracy for TSC. However, deep shot layers improved the SOM and TN prediction performances. Among the normalization approaches, the method based on the correction of Si line (DS) showed superior performance for improving quantitation of SOM and TN. The arithmetic average method (AA) was best for TSC prediction. Optimization of shot layer, number and normalization procedures of LIBS spectra resulted in fair prediction of SOM (residual prediction deviation of validation set, RPDV= 1.608), good prediction of TN (RPDV= 1.836), and very good quantitative analysis of TSC (RPDV= 2.456). Therefore, our findings illustrate very good potential for improving the quantitative accuracy of the LIBS soil spectra.

•Heavy metal resistance genes (HMRGs) were prevalent among E. coliand Salmonellafrom chicken farms and retail meat.•HMRGs correlated with disinfectant resistance genes (DRGs) and antibiotic resistance genes (ARGs).•HMRGs, DRGs and ARGs located on the same genetic element may lead to co-resistance to these compounds.

AbstractObjectives:This study aimed to trace the transmission source of Salmonella entericaserovar Typhimurium and Salmonella entericaserovar Enteritidis strains associated with enteric infections in Shanghainese children, and understand the molecular mechanism of resistance to third-generation cephalosporins and ciprofloxacin.Materials and Methods:The profiles of pulsed-field gel electrophoresis (PFGE) were compared among the isolates from children, animal, and environment. Antimicrobial susceptibility was determined using the minimal inhibitory concentrations and Kirby–Bauer disk diffusion method. Extended-spectrum β-lactamase (ESBL) producing isolates mediated by resistance genes were identified using polymerase chain reaction and sequencing.Results:Based on PFGE patterns, 49 (33.1%) of 148 human SalmonellaTyphimurium isolates located in the dominant PFGE clusters were genetically related to the isolates from poultry source, environment water, aquatic products, and reptiles, whereas 97 (97.0%) of 100 human SalmonellaEnteritidis isolates were genetically related to isolates from poultry and water. The rates of resistance to ceftriaxone among clinical SalmonellaTyphimurium and SalmonellaEnteritidis isolates were 42.0% and 14.2%, respectively. Besides, 35.1% of SalmonellaTyphimurium isolates displayed resistance to ciprofloxacin; 64.9% of SalmonellaTyphimurium isolates and 97.0% of SalmonellaEnteritidis isolates displayed reduced susceptibility to ciprofloxacin. Of 64 ESBL/AmpC-producing strains, CTX-M, TEM, DHA, and CMY were detected at frequencies of 86.0%, 62.5%, 7.8%, 3.1%, and 3.1%, respectively.Conclusions:The transmission sources of SalmonellaTyphimurium and SalmonellaEnteritidis infections in Shanghainese children were diverse. The high prevalence of resistance to third-generation cephalosporins and ciprofloxacin mediated by multiple molecular mechanisms needs continuous monitoring and intervention.

AbstractSalmonellaproducing β-lactamases has spread rapidly worldwide and poses a serious threat to human and animal health. In this study, we characterized 220 ceftriaxone (CRO)-resistant isolates identified among 3153 Salmonellafrom humans, animals, food, and water collected in Shanghai, China. They were assessed for antimicrobial susceptibility, phenotypic identification of extended-spectrum β-lactamases (ESBLs), and β-lactamase genes and integrons. CRO resistance in Salmonellaincreased from 5.0% in 2011 to 8.4% in 2013. SalmonellaEnteritidis (45.5%), SalmonellaTyphimurium (20.9%) from humans, and SalmonellaIndiana (14.5%) from poultry represented the majority of the CRO-resistant isolates. Many isolates were also resistant to other antimicrobials, including nalidixic acid (84.5%), sulfisoxazole (70.5%), and tetracycline (61.8%). Resistance to ciprofloxacin was also found in 33.6% of the isolates. Most isolates (98.2%) were confirmed as ESBL producers. Resistance genes such as blaCTX-M, blaTEM, and blaOXAwere detected in 207 (94.1%), 99 (45%), and 53 (24.1%) isolates, respectively. Three types of integron I and one type of integron II were identified in 13 (5.9%) and 2 (0.9%) isolates, respectively. The integrons encompassed 10 different genes: dfrA1/12/17/25, aadA1/2/5, sat2, orfF, and ybeA. Our study underscores concern for increasing CRO resistance, and highlights the widespread ESBL genes in Salmonella enterica.

Understanding changes in pathogen behavior (e.g. increased virulence, a shift in transmission channel) is critical for the public health management of emerging infectious diseases. Genome degradation via gene depletion or inactivation is recognized as a pathoadaptive feature of the pathogen evolving with the host. However, little is known about the exact role of genome degradation in affecting pathogenic behavior, and the underlying molecular detail has yet to be examined. Using large-scale global avian-restricted Salmonellagenomes spanning more than a century, we projected the genetic diversity of SalmonellaPullorum (bvSP) by showing increasingly antimicrobial-resistant ST92 prevalent in Chinese flocks. The phylogenomic analysis identified three lineages in bvSP, with an enhancement of virulence in the two recently emerged lineages (L2/L3), as evidenced in chicken and embryo infection assays. Notably, the ancestor L1 lineage resembles the Salmonellaserovars with higher metabolic flexibilities and more robust environmental tolerance, indicating stepwise evolutionary trajectories towards avian-restricted lineages. Pan-genome analysis pinpointed fimbrial degradation from a virulent lineage. The later engineered fim-deletion mutant, and all other five fimbrial systems, revealed behavior switching that restricted horizontal fecal–oral transmission but boosted virulence in chicks. By depleting fimbrial appendages, bvSP established persistent replication with less proinflammation in chick macrophages and adopted vertical transovarial transmission, accompanied by ever-increasing intensification in the poultry industry. Together, we uncovered a previously unseen paradigm for remodeling bacterial surface appendages that supplements virulence-enhanced evolution with increased vertical transmission.

AbstractWe characterized antibiotic resistance profiles, antibiotic resistance-associated genes, and pulsed-field gel electrophoresis (PFGE) patterns of 145 Salmonella entericaserotype Typhimurium isolates from human infections and retail foods that were possibly responsible for salmonellosis outbreaks from 2008 to 2012 in Shanghai, China. Resistance to at least three antibiotics was found in 66.7% of chicken isolates, 76.5% of duck isolates, 77.8% of pork isolates, and 80.5% of human isolates. Seven antibiotic resistance phenotypes were detected in chicken isolates, 16 in pork isolates, 17 in duck isolates, and 50 in human isolates. No significant difference (p> 0.05) was found between Salmonellaisolates derived from human salmonellosis and from retail foods in terms of the percent resistance of ampicillin, amoxicillin/clavulanic acid, ceftiofur, ceftriaxone, nalidixic acid, chloramphenicol, gentamicin, kanamycin, streptomycin, tetracycline, sulfisoxazole, and sulfamethoxazole/trimethoprim. PFGE using XbaI and BlnI showed that some Salmonellaisolates recovered from human infections and retail foods had same or highly similar genetic profile. Same or similar antibiotic resistance profiles, antibiotic resistance associated genes (i.e., qnrA, qnrB, qnrS, aac(6′)-Ib, and oqxAB), gene cassettes (i.e., aadA2, dfrA12-aadA2, and aadA1), and mutations were detected in those isolates that exhibited high genetic similarities. These findings highlighted the frequent presence of SalmonellaTyphimurium in retail chicken, pork, duck, and humans.

AbstractSalmonella entericaserovar Enteritidis is the leading global cause of salmonellosis. A total of 146 SalmonellaEnteritidis isolates obtained from retail chicken products in Shanghai, China were characterized for their antimicrobial susceptibilities, virulence and antibiotic resistance gene profiles, and molecular subtypes using pulsed-field gel electrophoresis (PFGE). Approximately 42% (61/146) of the isolates were susceptible to all 13 antimicrobials tested. More than half of the isolates (50.70%) were resistant to ampicillin, 49.32% to sulfisoxazole, 17.12% to tetracycline, and 15.75% to doxycycline. Thirty (20.55%) isolates were resistant to three or more antimicrobials. The avrA, mgtC, and sopE virulence genes were identified in all isolates, while 97.2% and 92.4% were positive for bcfC and spvC genes, respectively. Genes associated with resistance to streptomycin (aadA), β-lactams (blaTEM, blaCMY, blaSHV, and blaCTX), tetracycline (tetA and tetB), and sulfonamides (sulI, sulII, and sulIII) were detected among corresponding resistant isolates. A total of 41 PFGE patterns were identified from 77 antimicrobial resistance (AMR) isolates and were primarily grouped into seven clusters (A–G), each with 90% similarity. The majority of SalmonellaEnteritidis isolates (63.63%, 49/77) shared the same PFGE cluster, indicating potential cross contamination during processing and cutting or working during retailing and marketing. A significantly (p< 0.05) lower percentage (<25%) of isolates belonging to clusters D and E were resistant to sulfisoxazole compared with those belonging to clusters A, B, C, F, and G (>80%), indicating that sulfisoxazole resistance might be associated with genetic content (PFGE profiles) of SalmonellaEnteritidis. This study provides important and updated information about the baseline antimicrobial-resistant data for food safety risk assessment of SalmonellaEnteritidis from retailed chicken in Shanghai, which is the first step for the development and implementation of China's AMR National Action Plan, and can be helpful for future surveillance activities to ensure the safety of the chicken supply.

Supplemental Digital Content is available in the text.

AbstractSalmonella entericaserotype Derby is among the three most common serotypes of nontyphoidal Salmonellaisolated from patients with diarrhea in China. In this study, 133 SalmonellaDerby isolates from human patients (n= 74) and foods of animal origin (n= 59) in Shanghai, China, between September 2013 and December 2014, were selected to study its phenotypic characteristics and genetic diversity. The isolates were subjected to antimicrobial susceptibility testing, plasmid replicon typing, virulence profile determination, and molecular subtyping by pulsed-field gel electrophoresis (PFGE). Isolates were frequently resistant to tetracycline (87.22%), sulfisoxazole (74.44%), and streptomycin (62.41%), and a low frequency of resistance was found toward ofloxacin (3.01%), ceftazidime (2.26%), and cefepime (1.50%); in addition, 93 (69.92%) isolates were multidrug resistant. The most common plasmid incompatibility replicon types were the IncF family (FIA, 51.31%; FIC, 27.82%; and FIB, 21.80%) and IncP types (35.34%): these plasmid types may be associated with the spread of antibiotic resistance and virulence genes. All isolates were positive for the Salmonellapathogenicity island (SPI) gene avrAand the fimbrial gene bcfCfrom among the 10 virulence genes detected, and most of them carried ssaQ(99.25%), mgtC(97.74%), siiD(98.50%), sopB(97.74%), and sopE(96.99%). PFGE showed 68 patterns in nine main clusters at an 85% similarity threshold. Most of the isolates from different sources possessed the same fingerprints or molecular profiles in each cluster, which strongly suggests the possibility that foods of animal origin, especially pork, serve as an important source for human infection. Moreover, this diversity may suggest strains originating from multiple clones. Therefore, surveillance on this serotype should be strengthened to prevent transmission of SalmonellaDerby from foods of animal origin, especially pork, to humans.

SalmonellaSenftenberg is an important nontyphoidal Salmonellaserovar that causes gastrointestinal disease worldwide. In total, 130 SalmonellaSenftenberg strains obtained from humans, food, and the environment in Shanghai, People's Republic of China, were characterized for antimicrobial susceptibility and subjected to molecular typing. Our findings indicated that most (96 of 130, 73.8%) of the strains were susceptible to all 13 antimicrobial compounds tested, whereas only two strains (1.5%) were resistant to two antimicrobial compounds. In total, 56 pulsed-field gel electrophoresis profiles were identified, including four main pulsed-field gel electrophoresis profiles (X2, X3, X4, and X5) that showed 95.7% genetic similarity. Our study revealed that the strains of SalmonellaSenftenberg from food and the environment shared a high correlation of genetic similarity with those from humans, highlighting the potential links that exist among the strains recovered from different sources in Shanghai.

AbstractTerrapins and turtles are known to transmit Salmonellato humans. However, little was known about the occurrence of this pathogen in soft-shelled terrapin that is a popular delicacy in Chinese and other East Asian cuisines. We isolated and characterized 82 (24.4%) isolates of Salmonellafrom 336 fecal samples of soft-shelled terrapins (51 of 172; 29.7%) and pet turtles (31 of 164; 18.9%) in Shanghai. SalmonellaThompson was the most common serotype (17.1%) among others. Many isolates (84.1%) were resistant to multiple antimicrobials (≥3). Molecular analysis of SalmonellaThompson and SalmonellaTyphimurium using pulsed-field gel electrophoresis unveiled a close genetic relationship between several human and terrapin isolates. Our results highlight the risk associated with the handling and consumption of turtles and their role in the spread of Salmonellain the human salmonellosis.

Supplemental Digital Content is available in the text.

AbstractSalmonella entericaserovar Stanley is an important serovar that has been increasingly identified in human salmonellosis. The present study aimed to investigate the antimicrobial resistance and molecular typing of 88 SalmonellaStanley strains isolated from humans (diarrhea patients, n= 64; and healthy carrier, n= 1), foods (aquatic products, n= 16; vegetable, n= 1; and pork, n= 1), and environment (waste water, n= 2; and river water, n= 3) in Shanghai, China from 2006 to 2012. Nearly half of the strains were resistant to sulfafurazole (43/88, 48.9%), and many were resistant to streptomycin (35/88, 39.8%), tetracycline (22/88, 25%), and nalidixic acid (19/88, 21.6%). Approximately a quarter of the strains (24/88, 27.3%) were resistant to more than three antimicrobials, and five had ACSSuT resistance type. Six clusters (A–F) were identified by pulsed-field gel electrophoresis (PFGE) with 80% similarity. Interestingly, strains in the same cluster identified by PFGE possessed similar antibiotic resistance patterns. PFGE typing also indicated that aquatic products might serve as a transmission reservoir for SalmonellaStanley infections in humans.

AbstractThe aim of this study was to determine the molecular subtyping and antimicrobial susceptibility characteristics of Campylobacter coliisolates from different sources in China. One hundred thirteen C. coliisolates were subtyped by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and porAand flaAshort variable region (SVR) nucleotide sequences. Cluster analysis was performed based on the PFGE and sequence types (ST). Eighty-four PFGE patterns (SmaI) were observed in 113 isolates. Fifty-four STs (28 novel) and three clonal complexes (CC), 86% of which were clustered to CC828, were observed, as well as 52 porAand 37 flaA-SVR sequence alleles. MLST, porA, and flaA-SVR analysis demonstrated that many isolates from diarrheal patients shared identical genotypes with chicken isolates. Minimum inhibitory concentration values of 10 antibiotics were analyzed for 109 isolates isolated in 2011 using the E-test method. The most frequently observed resistance agents were nalidixic acid (100%) and ciprofloxacin (100%), followed by levofloxacin (99%), tetracycline (94%), metronidazole (93%), erythromycin (61%), streptomycin (72%), gentamicin (59%), ampicillin (50%), and chloramphenicol (29%). Multidrug resistance was detected in 108 of 109 C. coliisolates (99%).

ABSTRACTSalmonella entericaserovar Senftenberg is a common nontyphoidal Salmonellaserotype which causes human Salmonellainfections worldwide. In this study, 182 S. Senftenberg isolates, including 17 atypical non-hydrogen sulfide (H2S)-producing isolates, were detected in China from 2005 to 2011. The microbiological and genetic characteristics of the non-H2S-producing and selected H2S-producing isolates were determined by using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and clustered regularly interspaced short palindromic repeat (CRISPR) analysis. The phsoperons were amplified and sequenced. The 17 non-H2S-producing and 36 H2S-producing isolates belonged to 7 sequence types (STs), including 3 new STs, ST1751, ST1757, and ST1758. Fourteen of the 17 non-H2S-producing isolates belonged to ST1751 and had very similar PFGE patterns. All 17 non-H2S-producing isolates had a nonsense mutation at position 1621 of phsA. H2S-producing and non-H2S-producing S. Senftenberg isolates were isolated from the same stool sample from three patients; isolates from the same patients displayed the same antimicrobial susceptibility, ST, and PFGE pattern but could be discriminated based on CRISPR spacers. Non-H2S-producing S. Senftenberg isolates belonging to ST1751 have been prevalent in Shanghai, China. It is possible that these emerging organisms will disseminate further, because they are difficult to detect. Thus, we should strengthen the surveillance for the spread of this atypical S. Senftenberg variant.

SalmonellaEnteritidis is an important foodborne pathogen with high prevalence of resistance to cephalosporins, imposing a serious threat to public health. Therefore, a total of 162 SalmonellaEnteritidis 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 blaCTX-M-55(n= 13), blaCTX-M-101(n= 1), and blaCTX-M-153(n= 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 SalmonellaEnteritidis interspecies. Furthermore, conjugation experiments were successfully performed in 13 of 15 isolates, and blaCTX-M-55was present on conjugative plasmids with sizes ranging from 54.7 to 173.4 kb. Compared with recipient Escherichia coliC600, transconjugants conferred elevated MICs for cephalosporins ranging from 2- to 2048-fold. The genetic structure surrounding of blaCTX-M-55gene in transconjugants were ΔISEcp1-blaCTX-M-55-orf477(n= 8) and ISEcp1-blaCTX-M-55-orf477(n= 3), respectively. Taken together, blaCTX-Mon the plasmids might contribute to cephalosporin resistance in SalmonellaEnteritidis, and conjugative transfer of blaCTX-M-55might facilitate the spread of cephalosporin resistance in SalmonellaEnteritidis. Hence, effective mitigation measurements are needed to reduce the threat caused by cephalosporin-resistant SalmonellaEnteritidis to public health.

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 × 10–5to 1.65 × 10–4S·cm–1, lithium ion transference number (tLi+) 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.

ABSTRACTHere, we report for the first time a waterborne outbreak of Shigella sonneiin China in 2015. Eleven multidrug-resistant (MDR) S. sonneiisolates were recovered, showing high resistance to azithromycin and third-generation cephalosporins in particular, due to an mph(A)- and blaCTX-M-14-harboring IncB/O/K/Z group transmissible plasmid of 104,285 kb in size. Our study highlights the potential prevalence of the MDR outbreak of S. sonneiin China and its further dissemination worldwide with the development of globalization.

ABSTRACTIn this study, we report a novel mcr-1gene variant, named mcr-1.6, carried by an IncP plasmid in a colistin-resistant Salmonella entericaserovar Typhimurium isolate from a healthy person. Compared with mcr-1, the mcr-1.6gene contains two single-nucleotide polymorphisms, one of which results in an arginine to histidine variation (Arg536→His). The plasmid carrying the mcr-1.6gene was designated pMCR1.6_P053 and is similar to a recently discovered mcr-1-bearing plasmid found in Klebsiella pneumoniae.

ABSTRACTThe recently discovered colistin resistance element, mcr-1, adds to the list of antimicrobial resistance genes that rapidly erode the antimicrobial efficacy of not only the commonly used antibiotics but also the last-line agents of carbapenems and colistin. This study investigated the prevalence of the mobile colistin resistance determinant mcr-1in Salmonellastrains recovered from clinical settings in China and the transmission potential of mcr-1-bearing mobile elements harbored by such isolates. The mcr-1gene was recoverable in 1.4% of clinical isolates tested, with the majority of them belonging to Salmonella entericaserotype Typhimurium. These isolates exhibited diverse pulsed-field gel electrophoresis (PFGE) profiles and high resistance to antibiotics other than colistin and particularly to cephalosporins. Plasmid analysis showed that mcr-1was carried on a variety of plasmids with sizes ranging from ∼30 to ∼250 kb, among which there were conjugative plasmids of ∼30 kb, ∼60 kb, and ∼250 kb and nonconjugative plasmids of ∼140 kb, ∼180 kb, and ∼240 kb. Sequencing of representative mcr-1-carrying plasmids revealed that all conjugative plasmids belonged to the IncX4, IncI2, and IncHI2 types and were highly similar to the corresponding types of plasmids reported previously. Nonconjugative plasmids all belonged to the IncHI2 type, and the nontransferability of these plasmids was attributed to the loss of a region carrying partial or complete tragenes. Our data revealed that, similar to the situation in Escherichia coli, mcr-1transmission in Salmonellawas accelerated by various plasmids, suggesting that transmission of mcr-1-carrying plasmids between different species of Enterobacteriaceaemay be a common event.