Escherichia coli is an important foodborne pathogen and also plays key roles in dissemination of antimicrobial resistance genes (ARGs). However, current data on the prevalence of antimicrobial-resistant E. coli at different nodes of the pork supplying chain are still limited. Herein, we investigated drug-resistant phenotypes and molecular characteristics of E. coli strains isolated from different pig farms, slaughterhouses, and terminal markets in the Henan Province of China. A total of 191 (70.74%), 140 (35.09%), and 77 (30.20%) E. coli strains were isolated from 270, 399, and 255 samples collected from pig farms, slaughterhouses, and retailing markets, respectively. Antimicrobial susceptibility testing revealed that these 408 strains showed severe antimicrobial resistance profiles. Approximately 93.19% (178/191), 66.43% (93/140), and 67.53% (52/77) of the isolates from farms, slaughterhouses, and terminal markets were resistant to three of the nine antibiotic classes tested, respectively. Multilocus sequence typing showed that sequence types (STs) 10 and ST101 were commonly identified among the isolates from farms, slaughterhouses, and terminal markets. Isolates belonging to these two STs carried multiple ARGs, conferring resistance to the antibiotics tested. Two important ARGs with great public health concerns (mcr-1 and blaNDM-1) were found from these two STs. Isolates belonging to these two STs also carried several virulence factor-encoding genes, including astA, tsh, and traT, which might contribute to the pathogenesis of these isolates. The wide prevalence and distribution of these two STs in different nodes of pork supplying chain might represent a big public health threat and should receive more attention.
The emergence of carbapenem-resistant and colistin-resistant Enterobacteriaceae represents a great risk for public health. In this study, the phenotypical and genetic characteristics of eight carbapenem-resistant and colistin-resistant isolates from pig farms in China were determined by the broth microdilution method and whole genome sequencing. Antimicrobial susceptibility testing showed that the eight carbapenem-resistant and colistin-resistant strains were resistant to three aminoglycosides, twelve β-lactams, one of the phenicols, one of the tetracyclines, and one of the fluoroquinolones tested, simultaneously. The prediction of acquired resistant genes using the whole genome sequences revealed the co-existence of blaNDM-1 and mcr-1 as well as the other genes that were responsible for the multidrug-resistant phenotypes. Bioinformatics analysis also showed that the carbapenem-resistant gene blaNDM-1 was located on a putative IncFII-type plasmid, which also carried the other acquired resistant genes identified, including fosA3, blaTEM-1B and rmtB, while the colistin-resistant gene mcr-1 was carried by a putative IncX4-type plasmid. Finally, we found that these resistant genes/plasmids were conjugative, and they could be co-conjugated, conferring resistance to multiple types of antibiotics, including the carbapenems and colistin, to the recipient Escherichia coli strains.
Abstract To improve the forecasting accuracy of power load, the forecasting model based on sparrow search algorithm (SSA), variational mode decomposition (VMD), attention mechanism and long short-term memory (LSTM) was proposed. Firstly, SSA is used to optimize the number of decomposition and penalty factor in VMD and realize the decomposition operation of the initial data. Then, LSTM is used to predict each component, and on this basis, feature and temporal attention mechanisms are introduced. Feature attention mechanism is introduced to calculate the contribution rate of relevant input features in real time, and the feature weights are modified to avoid the limitations of traditional methods relying on the threshold of expert experience association rules. Temporal attention mechanism is applied to extract the historical key moments and improve the stability of the time series prediction effect. Finally, the final result is obtained by superimposing the prediction results of each component to complete the power load prediction. Practical examples show that, compared with other methods, the proposed model achieves the highest prediction accuracy, with an RMSE of 1.23, MAE of 0.99 and MAPE of 11.62%.
The expanding use of antimicrobials in livestock is an important contributor to the worldwide rapid increase in antimicrobial resistance (AMR). However, large-scale studies on AMR in livestock remain scarce. Here, we report findings from surveillance of E. coli AMR in pig farms in China in 2018-2019. We isolated E. coli in 1,871 samples from pigs and their breeding environments, and found AMR in E. coli in all provinces in mainland China. We detected multidrug-resistance in 91% isolates and found resistance to last-resort drugs including colistin, carbapenems and tigecycline. We also identified a heterogeneous group of O-serogroups and sequence types among the multidrug-resistant isolates. These isolates harbored multiple resistance genes, virulence factor-encoding genes, and putative plasmids. Our data will help to understand the current AMR profiles of pigs and provide a reference for AMR control policy formulation for livestock in China.
Enterobacteriaceae having chromosomally-encoded mcr-1 is rarely reported. In this study, we recovered a chromosomal mcr-1 carrying Escherichia coli, designated HeN100, from the feces of a diarrheal pig in China. Antimicrobial susceptibility testing showed that HeN100 was resistant to three aminoglycosides, twelve β-lactams including three carbapenems, one phenicol, two tetracyclines, two fluoroquinolones, nitrofurantoin, and colistin tested. Oxford Nanopore MinION sequencing revealed that the complete genomes of the multidrug resistant (MDR) HeN100 consisted of a single circular chromosome and five circular plasmids. Bioinformatical analysis determined HeN100 as ST695 and it contained many acquired resistance genes responsible for its MDR phenotypes, including colistin resistance mcr-1 and the carbapenem resistance blaNDM-1, and most of these genes were located on plasmids. However, the mcr-1 was found on the chromosome, and it was located between an IS30-like element ISApl1 and a PAP2-like encoding gene. These three genes consisted of an "ISApl1-mcr-1-orf" segment and inserted in high AT-rich regions. Finally, we found the blaNDM-1 was carried on an IncFII type conjugative plasmid. The conjugation frequency of this plasmid was 7.61 ± 2.11 × 10-5 per recipient, and its conjugation conferred resistance to carbapenems and other β-lactams, as well as aminoglycosides. The spread of this mcr-1/blaNDM-1-carrying E. coli ST695 represents a great concern of public health.
Abstract The emergence and dissemination of colistin resistance in Enterobacteriaceae mediated by plasmid-borne mcr genes in recent years now pose a threat to public health. In this study, we isolated and characterized colistin-resistant and/or mcr -positive E. coli from pig farms in Central China. Between 2018 and 2019, 594 samples were collected and recovered 445 E. coli isolates. Among them, 33 with colistin resistance phenotypes and 37 that were positive for mcr genes were identified, including 34 positive for mcr-1 , one positive for mcr-3 , and two positive for both mcr-1 and mcr-3 . An insertion of nine bases (“CTGGATACG”) into mcr-1 in four mcr -positive isolates led to gene dysfunction, and therefore did not confer the colistin resistance phenotype. Antimicrobial susceptibility testing revealed that 37 mcr -positive isolates showed severe drug resistance profiles, as 50% of them were resistant to 20 types of antibiotics. Multilocus sequence typing revealed a heterogeneous group of sequence types in mcr -positive isolates, among which ST10 (5/37), ST156 (5/37), and ST617 (4/37) were the predominant types. Plasmid conjugation assays showed that mcr -carrying plasmids of 25 mcr -positive isolates were conjugated with E. coli recipient, with conjugation frequencies ranging from 1.7 × 10 -6 to 4.1 × 10 -3 per recipient. Conjugation of these mcr genes conferred a colistin resistance phenotype upon the recipient bacterium. PCR typing of plasmids harbored in the 25 transconjugants determined six types of plasmid replicons, including IncX4 (14/25), FrepB (4/25), IncI2 (3/25), IncHI2 (2/25), FIB (1/25), and IncI1 (1/25). This study contributes to the current understanding of antibiotic resistance and molecular characteristics of colistin-resistant E. coli in pig farms.
To improve the prediction accuracy of the system load, this paper couples k-means clustering algorithm and neural network to predict the system load by taking into account the component characteristics of user load. Firstly, the typical curve of each 10kV distribution line is calculated. Secondly, the distribution lines are clustered into different categories through kmeans clustering according to the typical curves so that the user-side load can be effectively decomposed. Finally, the system load is predicted by using neural network with the load forecast result of different components as features. The experimental results show that the system load prediction considering the user-side load component analysis is beneficial to improve the prediction accuracy of the system load. This research has certain engineering application value.
Abstract Antimicrobial resistance (AMR) is one of the most urgent threats to the global public health, and the expanding use of antimicrobials in food animals is considered as a main reason for the worldwide rapid increasing of AMR. However, AMR in animals in many regions are poorly documented. China is the largest pig-rearing and pork consumption country in the world. In the present study, we identified AMR in pig farms from all provinces (including Tibet and Qinghai) of mainland China by investigation of a common indicator bacterium Escherichia coli from both pigs and the breeding environmental samples. A total of 2693 samples from pigs and environments in 67 pig farms in all 31 provinces of mainland China were collected between 1 October 2018 to 30 September 2019, and a total of 1871 E. coli strains were isolated. By testing the susceptibility of these 1871 E. coli isolates on 28 types of antibiotics that commonly used in both human and veterinary medicine, we found that resistance to tetracycline (96.26%), chloramphenicol (82.04%), moxifloxacin (81.56%), and trimethoprim/sulfamethoxazole (80.38%) were the broad phenotypes among these E. coli isolates from pig farms in China. A proportion of E. coli isolates were resistant to colistin (3.79%), carbapenems (imipenem [2.62%], meropenem [2.30%], ertapenem [2.46%]), and broad-spectrum-cephalosporins (ceftriaxone [29.56%], cefepime [14.00%]). More than 70% of the isolates displayed multidrug-resistant (MDR), and/or extensively drug-resistant (XDR) phenotypes, and MDR/XDR- E. coli was observed in pig farms in all provinces of mainland China. We also systematically revealed the distribution of O-serogroups, sequence types, resistance genes, virulence factors encoding genes, and putative plasmids of MDR/XDR- E. coli in pig farms from different provinces of China, and partially characterized the pathotypes of certain MDR/XDR- E. coli strains. In addition, the genetic transmission basis of the bla NDM , mcr , ESBL-encoding, fluoroquinolone-resistance, and tetX genes were addressed in this study. Most importantly, we suggested a very high genetic propensity of the pig farm-sourced MDR/XDR- E. coli in spreading into humans. To the best of our knowledge, this is the first study on a national scale that the resistance phenotypes and population genomics of E. coli in pig farms in China are revealed. Our data presented herein will help understand the current profile of AMR in pigs and also provide reference for policy formulation of AMR control action in livestock in China.
Escherichia coli (E. coli) is an important foodborne pathogen and a biomarker for monitoring antimicrobial resistance. Investigating the prevalence of E. coli in the poultry industry holds great importance, particularly in Henan province, a major poultry-producing region in China. Here, we investigated the antimicrobial resistance (AMR) phenotypes of E. coli strains obtained from the poultry industry in Henan, China. A total of 344 E. coli strains were isolated from 638 samples collected from seven farms, three slaughterhouses, and ten terminal markets. Approximately 96.4%, 81.7%, and 52.5% of the isolates from the farms, slaughterhouses, and terminal markets exhibited multidrug resistance. Whole-genome sequencing was performed on 169 strains to reveal their genomic characteristics. The sequence type (ST) analysis revealed that ST10 and ST156 were the most frequent types within the poultry supply chain, whereas ST10 and ST162 were commonly found across the farms, slaughterhouses, and terminal markets. Fourteen ST10 E. coli strains belonged to phylogenetic group A, while fifteen ST165 and six ST162 E. coli strains belonged to phylogenetic group B1. In addition, several antimicrobial resistance genes and virulence factor genes were identified. The blaNDM-5 gene mediated carbapenem resistance in two E. coli strains, while mcr-1-mediated colistin resistance was detected in nine E. coli strains. Phylogenetic group A exhibited fewer virulence genes compared to other groups of E. coli. Plasmid replicons, such as IncFIB (AP001918), IncX1, IncFIC (FII), and IncFII (pHN7A8), were frequently observed. These findings provide valuable insights into the current AMR profiles of E. coli strains isolated from the poultry industry in Central China and highlight the need to implement good manufacturing practices and reduce antibiotic usage to mitigate potential risks associated with E. coli.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)