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Highlights Developed more efficient boron activation strategies, while establishing various low-melting growth systems. The preparation temperature of boron nitride nanotubes has been reduced to 850 °C.

ABSTRACT The extended-spectrum β-lactamase (ESBL) gene, blaVEB-1, was identified for the first time in an Escherichia coli clinical isolate, JARB-RN-0061, from blood cultures in a Japanese general hospital in 2021. The isolate exhibited high resistance to broad-spectrum cephalosporins, including ceftazidime (MIC >128 mg/L) and cefepime (MIC = 16 mg/L). blaVEB-1 was identified during whole-genome sequencing and characterization of the isolate. JARB-RN-0061 belonged to the B2-O2:K1:H7-ST95-fimH41 lineage and was classified as presumptive extraintestinal pathogenic E. coli (ExPEC) and uropathogenic E. coli (UPEC). Moreover, the strain harbored multiple virulence genes on the chromosome. The Col156/IncFIB(AP001918)/IncFII(29)-type plasmid (114,216 bp), with clbB and tcpC genes involved in bacteremia, was unique to the fimH41 subclone. The blaVEB-1 gene was located on a non-typeable and non-conjugative plasmid, pJARB-RN-0061_VEB-1 (17,093 bp). It was embedded in the class 1 integron In1883-like, with multidrug resistance gene cassettes for aacA4, aadB, cmlA5, qnrVC4, and dfrA14. Notably, comparative analysis of the complete sequence of plasmid pJARB-RN-0061_VEB-1 revealed that it was highly homologous to the blaVEB-1-harboring plasmid, pMS2H7VEB-1 (100% coverage and 99.99% identity), except for the Tn3 family transposon (4,931 bp) and the plasmid pRHBSTW-00138_5 (97% coverage and 100% identity) harbored by Klebsiella quasipneumoniae subsp. similipneumoniae strains from hospital sewage in Japan and wastewater influent in the United Kingdom, respectively. The emergence of a human pathogenic E. coli clinical isolate with the blaVEB-1-carrying plasmid in the B2-ST95 worldwide pandemic lineage, characterized by the virulence potential of ExPEC or UPEC but a low prevalence of antimicrobial resistance, would raise public health concerns.IMPORTANCEESBLs are plasmid-mediated enzymes that confer resistance to clinically significant antimicrobial agents, such as broad-spectrum cephalosporins. Recently, the rapid spread of CTX-M-type ESBL-producing E. coli has become a global issue, including in Japan, where ESBL production in human pathogenic E. coli, such as the ExPEC and UPEC lineages, which typically harbor several virulence genes, is a severe public health concern. To date, VEB (Vietnamese extended-spectrum β-lactamase) producers have been found only in hospital wastewater and rivers in Japan. Thus, we describe the first detection of a very rare human-derived blaVEB-1 gene in the E. coli B2-ST95 pandemic clonal lineage that is highly associated with ExPEC and UPEC in a Japanese clinical setting. Furthermore, we characterized the genomic features of plasmids harboring the class 1 integron-borne blaVEB-1. Our findings highlight the significance of closely monitoring ESBL-producing E. coli isolates to prevent the potential dissemination of this resistance determinant in Japan.

The electromagnetic radiation signal generated by loaded coal and rock is widely used to predict coal and rock dynamic disasters. However, due to the presence of significant electromagnetic interference at the coal mine site, the accuracy of the collected signals is insufficient. For the collected noisy charge induction signals, the wavelet threshold function of traditional denoising methods has problems such as non-progressiveness and discontinuity at the threshold. In order to achieve a better signal noise reduction effect, this paper proposes a collection based on an improved wavelet threshold (IWT) function and an improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) combined denoising algorithm. It overcomes mode aliasing and optimizes signal smoothness. Firstly, the algorithm is used to decompose the noisy signal and calculate the intrinsic mode function (IMF) and correlation coefficient of each order to distinguish the noise from the correlated signal. Then, the IMF component dominated by the signal is reconstructed to complete the denoising. The simulation and experimental results show that this algorithm can effectively remove noise in charge induction signals, and its signal-to-noise ratio (SNR) is improved by 2.3482 and 0.095 compared to six algorithms such as IWT and VMD, respectively. Compared with four algorithms, including the improved threshold function and the improved threshold function combined with Ensemble Empirical Mode Decomposition (EEMD), its noise-to-noise ratio (Rnn) decreased by 3.112, showing good noise reduction performance. The results presented in this paper provide a new method for collecting real charge induction signals.

Abstract Antimicrobial resistance is a global health concern; Enterobacterales resistant to third-generation cephalosporins (3GCs) and carbapenems are of the highest priority. Here, we conducted genome sequencing and standardized quantitative antimicrobial susceptibility testing of 4,195 isolates of Escherichia coli and Klebsiella pneumoniae resistant to 3GCs and Enterobacterales with reduced meropenem susceptibility collected across Japan. Our analyses provided a complete classification of 3GC resistance mechanisms. Analyses with complete reference plasmids revealed that among the bla CTX-M extended-spectrum β-lactamase genes, bla CTX-M-8 was typically encoded in highly similar plasmids. The two major AmpC β-lactamase genes were bla CMY-2 and bla DHA-1. Long-read sequencing of representative plasmids revealed that approximately 60% and 40% of bla CMY-2 and bla DHA-1 were encoded by such plasmids, respectively. Our analyses identified strains positive for carbapenemase genes but phenotypically susceptible to carbapenems and undetectable by standard antimicrobial susceptibility testing. Systematic long-read sequencing enabled reconstruction of 183 complete plasmid sequences encoding three major carbapenemase genes and elucidation of their geographical distribution stratified by replicon types and species carrying the plasmids and potential plasmid transfer events. Overall, we provide a blueprint for a national genomic surveillance study that integrates standardized quantitative antimicrobial susceptibility testing and characterizes resistance determinants.

Nitrogen (N) deposition rates have notably increased around the world, especially in high-altitude regions like the Qinghai–Tibetan Plateau (QTP). We conducted a six-year comprehensive experiment to simulate nitrogen deposition in an alpine grassland area near Qinghai Lake. Four levels of nitrogen depositions, i.e., 0 (CK), 8 kg N ha−1year−1 (N1), 40 kg N ha−1year−1 (N2), and 72 kg N ha−1year−1 (N3), with three replicates for each N treatment, were tested annually in early May and early July, with the meticulous collection of plant and soil samples during the peak growth period from 15 July to 15 August. We used the null model to evaluate the impact of environmental filtration and interspecific competition on the dynamics of the plant community was assessed based on the level of discrete species affinities within the plant community by constructing a phylogenetic tree. The results showed that the environmental filter was the predominant driver for the change of community’s genealogical fabric. The N2 and N3 treatments increased the influence of soil factors on the change of plant community structure. Climatic factors played a crucial role on the change of plant community in the CK grassland area, while soil factors were dominant in the N1- and N3-treated grasslands.

ABSTRACTIn 2020, the Ralstonia mannitolilytica strain JARB-RN-0044 was isolated from a midstream urine sample of an elderly hospitalized patient in Japan and was highly resistant to carbapenem (i.e., imipenem, meropenem, and doripenem). Whole-genome sequencing revealed that the complete genome consists of two replicons, a 3.5-Mb chromosome and a 1.5-Mb large non-chromosomal replicon which has not been reported in R. mannitolilytica, and referred to as the “megaplasmid” in this study based on Cluster of Orthologous Group of proteins functional analysis. The strain JARB-RN-0044 harbored two novel OXA-60 and OXA-22 family class D β-lactamase genes blaOXA-1176 and blaOXA-1177 on the megaplasmid. Cloning experiments indicated that Escherichia coli recombinant clone expressing blaOXA-1176 gene showed increased minimum inhibitory concentrations (MICs) of imipenem, meropenem, and doripenem, indicating that blaOXA-1176 gene encodes carbapenemase. In contrast, E. coli recombinant clone expressing blaOXA-1177 gene showed increased MICs of piperacillin and cefazolin, but not of carbapenem. Interestingly, the 44.6 kb putative prophage region containing genes encoding phage integrase, terminase, head and tail protein was identified in the downstream region of blaOXA-1176 gene, and comparative analysis with some previously reported R. mannitolilytica isolates revealed that the prophage region was unique to strain JARB-RN-0044. The existence of a highly carbapenem-resistant R. mannitolilytica isolate may raise human health concerns in Japan, where the population is rapidly aging.IMPORTANCERalstonia mannitolilytica is an aerobic non-fermenting Gram-negative rod commonly found in aquatic environments and soil. The bacteria can occasionally cause severe hospital-acquired bloodstream infections in immunocompromised patients and it has been recently recognized as an emerging opportunistic human pathogen. Furthermore, some R. mannitolilytica isolates are resistant to various antimicrobial agents, including β-lactams and aminoglycosides, making antimicrobial therapy challenging and clinically problematic. However, clinical awareness of this pathogen is limited. To our knowledge, in Japan, there has been only one report of a carbapenem-resistant R. mannitolilytica clinical isolate from urine by Suzuki et al. in 2015. In this study, whole-genome sequencing analysis revealed the presence and genetic context of novel blaOXA-1176 and blaOXA-1177 genes on the 1.5 Mb megaplasmid from highly carbapenem-resistant R. mannitolilytica isolate and characterized the overall distribution of functional genes in the chromosome and megaplasmid. Our findings highlight the importance of further attention to R. mannitolilytica isolate in clinical settings.

Extended form of damage mechanics analysis of Ladeveze and coworkers helps examine damage mechanics of two-dimensional woven SiC/SiC ceramic matrix composites. Prediction of damage development process using four-node quadrilateral elements demonstrates the efficiency of the theory. Association of finite element method and damage form the basis of flexural analysis.

Summary: A high ratio of severe mitochondrial defects causes multiple human mitochondrial diseases. However, until now, the in vivo rescue signal of such mitochondrial defect effects has not been clear. Here, we built fly mitochondrial defect models by knocking down the essential mitochondrial genes dMterf4 and dMrps23. Following genome-wide RNAi screens, we found that knockdown of Med8/Tfb4/mtSSB/PolG2/mtDNA-helicase rescued dMterf4/dMrps23 RNAi-mediated mitochondrial defect effects. Extremely surprisingly, they drove mtDNA replication outside mitochondria through the Med8/Tfb4-mtSSB/PolG2/mtDNA-helicase axis to amplify cytosolic mtDNA, leading to activation of the cGAS-Sting-like IMD pathway to partially mediate dMterf4/dMrps23 RNAi-triggered effects. Moreover, we found that the Med8/Tfb4-mtSSB/PolG2/mtDNA-helicase axis also mediated other fly mitochondrial gene defect-triggered dysfunctions and Drosophila aging. Overall, our study demarcates the Med8/Tfb4-mtSSB/PolG2/mtDNA-helicase axis as a candidate mechanism to mediate mitochondrial defect effects through driving mtDNA extramitochondrial replication; dysfunction of this axis might be used for potential treatments for many mitochondrial and age-related diseases.

ABSTRACT Colistin, a last-line antimicrobial agent, is recommended for the treatment of severe infections caused by multidrug-resistant (MDR) microorganisms. However, reports on plasmid-mediated mobilized colistin resistance (mcr) genes have prompted the importance of routine colistin resistance surveillance. Herein, we report the emergence of Enterobacter cloacae CST17-2 and Raoultella ornithinolytica CST129-1 carrying an mcr-9.1 gene in vegetables from Japan. A total of 308 colistin-resistant isolates were retrieved from 200 fresh vegetables in Hiroshima Prefecture, Japan. PCR detection of mcr-1 to mcr-9 was conducted. While none of the isolates detected positive for mcr-1 to mcr-8 genes, we found two (0.65%) positive strains, E. cloacae CST17-2 and R. ornithinolytica CST129-1, that harbored mcr-9.1 allele. These isolates were subjected to phenotypic susceptibility testing, whole-genome sequencing (WGS), PCR-based replicon typing, and conjugation experiment. We found that both isolates had high colistin resistance [minimum inhibitory concentration (MIC) 16 or >64 µg/mL] and showed MDR phenotypes. WGS of both isolates revealed mcr-9 on a plasmid of the IncHI2/HI2A backbone. The mcr-9-bearing plasmid, pCST17-2_1, was self-transferable, although the pCST129-1_1 plasmid was not. Despite being colistin-resistant, the so-called two-component regulatory operon, qseBC, which induces polymyxin resistance, was absent from the genetic arrangements downstream of mcr-9 in R. ornithinolytica CST129-1. Nonetheless, a conjugation experiment demonstrated that mcr-9 in a Raoultella-type background is capable of mediating colistin resistance. In silico genomic analysis and comparison revealed distinct genetic structures surrounding mcr-9, especially in the downstream vicinities. The E. cloacae CST17-2 strain is of sequence-type ST738, a sequence type that has emerged in mcr-9.1-containing E. cloacae. Remarkably, we report the first mcr-9-carrying colistin-resistant Enterobacteriaceae isolated from Japanese vegetables, which is a grave public health concern. Our findings highlight the importance of strict epidemiological monitoring to track and/or prevent further dissemination of mcr homologs across the vegetable industry. IMPORTANCE Plasmid-mediated mobile colistin-resistance genes have been recognized as a global threat because they jeopardize the efficacy of colistin in therapeutic practice. Here, we described the genetic features of two mcr-9.1-carrying Gram-negative bacteria with a colistin-resistant phenotype derived from vegetables in Japan. The colistin-resistant mcr-9.1, which has never been detected in vegetables, was located on a large plasmid in Enterobacter cloacae CST17-2 and Raoultella ornithinolytica CST129-1, suggesting a high chance of horizontal gene transfer. To the best of our knowledge, this is the first report of mcr-9 in R. ornithinolytica. This study indicates that fresh vegetables might be a potential source for the transmission of mcr-9 genes encoding resistance to frontline (colistin) and clinically relevant antimicrobials. The study also provides additional consideration for colistin use and the relevance of routine surveillance in epidemiological perspective to curb the continuous spread of mcr alleles.

ABSTRACT The spread of the gene encoding the NDM-type carbapenemase, bla NDM, poses a serious threat to clinical practice and public health. This gene is usually carried by transferable plasmids, which facilitates its rapid spread among various species of Enterobacterales. Plasmids with the IncX3 replicon play a major role in the spread of bla NDM in Asian countries. In this study, we conducted genomic sequencing and a comparative analysis of the IncX3-type plasmids harboring bla NDM-5 and bla NDM-16b, a single-nucleotide variant of bla NDM-5, isolated in a national antimicrobial-resistant bacterial genomic surveillance in Japan (Japan Antimicrobial Resistant Bacterial Surveillance), which was carried out during 2019–2020. We compared five plasmids harboring bla NDM-5 and one plasmid harboring bla NDM-16b. They were highly identical and differed in several nucleotide substitutions or variations in insertion sequences, although they were carried by different species or genotypes. Notably, bla NDM-16b-carrying pJBBDACG-19-0070 was identical to a plasmid carrying bla NDM-5 except for one nucleotide substitution in the bla NDM gene throughout the 46 kb sequences. Transformants carrying these two plasmids showed comparative resistance to carbapenems, indicating that a substitution on the NDM enzyme (Ala233 to Val) did not affect carbapenem resistance, at least under normal experimental conditions. A database search revealed that several identical plasmids carrying bla NDM-5 were reported from neighboring countries, mainly China, before our surveillance period. Our analysis suggested that the IncX3 plasmid harboring bla NDM-5 is spreading in Japan, and bla NDM-16b emerged from a single nucleotide substitution on the plasmid, with widespread dissemination in Asian countries. IMPORTANCE IncX3 plasmids harboring bla NDM-5 play a major role in the spread of carbapenem resistance in Asia, particularly in China, in clinical and environmental settings. In this study, we present that Enterobacterales isolates carrying IncX3 plasmids harboring bla NDM-5 have been disseminated in Japan, where their identification was previously rare. In addition, bla NDM-16b, a single-nucleotide variant of bla NDM-5, was found to be carried by an identical IncX3 plasmid. A comparative sequence analysis revealed that the bla NDM-16b gene emerged from a single nucleotide substitution on an IncX3 plasmid harboring bla NDM-5. The bla NDM-16b gene did not confer elevated carbapenem resistance compared to bla NDM-5 in our assay using transformants carrying the plasmid harboring either of these genes, although the A233V substitution was reported to confer stability to the enzyme in ion-depleted conditions. Nevertheless, vigilance regarding the emergence of novel variants is required.

Data of the awareness level of college students in China about Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS) knowledge are limited. Also, the attitudes towards HIV rapid testing remain unknown among this population. Therefore, this study aimed to evaluate the awareness of HIV/AIDS knowledge and attitudes towards HIV rapid testing among Chinese college students. An online cross-sectional survey was performed in 2020. A total of 1,474 participants were finally included. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine associated factors for the cognitive levels and attitudes by multivariable logistic regression. Spearman rank correlation was used to examine the relationship between HIV/AIDS-related knowledge and attitudes. About 91% of participants had a high cognitive level on HIV/AIDS-related knowledge and 84.7% held a positive attitude towards the HIV rapid testing. Postgraduates (OR = 1.75, 95% CI: 1.16–2.66) and females (OR = 1.69, 95% CI: 1.13–2.52) were more knowledgeable. Females' attitudes towards the HIV rapid testing were more positive (OR = 1.91, 95% CI: 1.40–2.62). Moreover, the knowledge was positively correlated with attitudes towards the rapid testing (Spearman r = 0.14, p