Raman-Based Antimicrobial Susceptibility Testing on Antibiotics of Last Resort.

Background: Antibiotic resistance represents a serious global health challenge, particularly with the emergence of strains resistant to last-resort antibiotics such as tigecycline, polymyxin B, and vancomycin. Urgent measures are required to alleviate this situation. To facilitate the judicious use of antibiotics, rapid and precise antimicrobial susceptibility testing (AST) is essential. Heavy water (deuterium oxide, D2O)-labeled Raman spectroscopy has emerged as a promising time-saving tool for microbiological testing. Methods: Deuterium incorporation and experimental conditions were examined to develop and apply a Raman-based AST method to evaluate the efficacy of last-resort antibiotics, including tigecycline, polymyxin B, and vancomycin, against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecium. Essential agreement and categorical agreement were used to assess the metabolism inactivation concentration based on Raman spectroscopy (R-MIC)-a new metric developed in this study-and minimum inhibitory concentration (MIC) determined via the traditional microdilution broth method. Spearman's rank correlation coefficient was employed to measure the association between R-MIC and MIC values. Results: The Raman-based AST method achieved a 100% categorical agreement (92/92) with the traditional microdilution broth method within five hours, while the traditional method required approximately 24 h. The R-MIC values shared 68.5% (63/92) consistency with the MIC values. In addition, the R-MIC and MIC values were highly correlated (Spearman's r=0.96), resulting in an essential agreement of 100%. Conclusion: Our optimized experimental method and conditions indicate that Raman-based AST holds great promise as a solution to overcome the time-consuming challenges of traditional AST methods.

Proteomics profiling of ertapenem challenged major porin deficient carbapenem-resistant Klebsiella pneumoniae.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an urgent threat to human health. Major outer membrane proteins (OMPs) porin mutation is one important resistance mechanism of CRKP, and may also affect the inhibition activity of ß-lactam and ß-lactamase inhibitor combinations. The ertapenem-resistant K. pneumoniae strain 2018B120 with major porin mutations was isolated from a clinical patient. Genomic and time-series proteomic analyses were conducted to retrieve the ertapenem-challenged response of 2018B120. The abundance changing of proteins from PTS systems,  ABC transporters, the autoinducer 2 (AI-2) quorum sensing system, and antioxidant systems can be observed. Overexpression of alternative porins was also noticed to balance major porins' defection. These findings added a detailed regulation network in bacterial resistance mechanisms and gave new insights into bypass adaptation mechanisms the porin deficient bacteria adopted under carbapenem antibiotics pressure. SIGNIFICANCE: Outer membrane porins deficiency is an important mechanism of carbapenem resistance in K. pneumoniae. Comprehensive genomic and proteomic profiling of an ertapenem-resistant K. pneumoniae strain 2018B120 gives a detailed systematic regulation network in bacterial resistance mechanisms. Overexpression of alternative porins to balance major porins' defection was noticed, giving new insights into bypass adaptation mechanisms of porin deficient bacteria.

Innovative Design of a Cloud Tour Guide Robot for Smart Cities under the Principle of System Innovation Design.

In light of the ongoing occurrence of epidemics, the general populace frequently makes the decision to curtail their nomadic lifestyle in order to protect both their health and their safety. This has resulted in a number of issues, the most notable of which are the drop in the people's living happiness index and the poor business that the tourism industry has been experiencing as a result. Therefore, the idea of "cloud tourism" is undoubtedly the first candidate for the tourism industry, and in order to meet the requirements of cloud tourism, it is necessary to have an entirely new system to serve this, of which the scenic guide robot is an important part. At the same time, the quickening development of 5G technology offers solutions that may be put into practice for the multifurther IoT's expansion in smart cities. People will be able to experience the real outdoors without having to leave their homes, which will improve the people's well-being and alleviate the chilly status quo in the tourism industry. This is the plan, and it will be accomplished through the use of innovative guide robots that will make the experience more convenient and reliable.

Pan-Genome Analysis of Laribacter hongkongensis: Virulence Gene Profiles, Carbohydrate-Active Enzyme Prediction, and Antimicrobial Resistance Characterization.

Laribacter hongkongensis is a new emerging foodborne pathogen that causes community-acquired gastroenteritis and traveler's diarrhea. However, the genetic features of L. hongkongensis have not yet been properly understood. A total of 45 aquatic animal-associated L. hongkongensis strains isolated from intestinal specimens of frogs and grass carps were subjected to whole-genome sequencing (WGS), along with the genome data of 4 reported human clinical strains, the analysis of virulence genes, carbohydrate-active enzymes, and antimicrobial resistance (AMR) determinants were carried out for comprehensively understanding of this new foodborne pathogen. Human clinical strains were genetically more related to some strains from frogs inferred from phylogenetic trees. The distribution of virulence genes and carbohydrate-active enzymes exhibited different patterns among strains of different sources, reflecting their adaption to different host environments and indicating different potentials to infect humans. Thirty-two AMR genes were detected, susceptibility to 18 clinical used antibiotics including aminoglycoside, chloramphenicol, trimethoprim, and sulfa was checked to evaluate the availability of clinical medicines. Resistance to Rifampicin, Cefazolin, ceftazidime, Ampicillin, and ceftriaxone is prevalent in most strains, resistance to tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin, and levofloxacin are aggregated in nearly half of frog-derived strains, suggesting that drug resistance of frog-derived strains is more serious, and clinical treatment for L. hongkongensis infection should be more cautious.

The Temporal and Spatial Distributions and Influencing Factors of Transboundary Pollution in China.

Transboundary pollution between neighboring regions seriously affects the efficiency of overall environmental governance; however, there are few studies focused on how to estimate the degree of transboundary pollution between different regions. With China as a case study, this article developed a new measurement to estimate the degree of transboundary pollution among regions, and comprehensively investigated the influencing factors of transboundary pollution in China between 2000 and 2013. The results indicate that transboundary pollution effects exist in China. In ascending order, the regions most affected overall by transboundary pollution from polluting enterprises were as follows: eastern region < central region < western region. The reduction in transboundary pollution effects was most prominent for severely polluting enterprises in the eastern and western regions and lightly polluting enterprises in the central region. An analysis of the influencing factors reveals that the regional environmental regulation intensity has a negative feedback effect on the transboundary pollution effects. These findings indicate that polluting enterprises in regions with a low environmental regulation intensity are more inclined to operate in border areas to obtain both the environmental benefits associated with the low local environmental regulation intensity and the market economy benefits associated with neighboring urban regions, thereby aggravating environmental pollution in border areas.