Prediction of carbapenem-resistant gram-negative bacterial bloodstream infection in intensive care unit based on machine learning.

BACKGROUND: Predicting whether Carbapenem-Resistant Gram-Negative Bacterial (CRGNB) cause bloodstream infection when giving advice may guide the use of antibiotics because it takes 2-5 days conventionally to return the results from doctor's order. METHODS: It is a regional multi-center retrospective study in which patients with suspected bloodstream infections were divided into a positive and negative culture group. According to the positive results, patients were divided into the CRGNB group and other groups. We used the machine learning algorithm to predict whether the blood culture was positive and whether the pathogen was CRGNB once giving the order of blood culture. RESULTS: There were 952 patients with positive blood cultures, 418 patients in the CRGNB group, 534 in the non-CRGNB group, and 1422 with negative blood cultures. Mechanical ventilation, invasive catheterization, and carbapenem use history were the main high-risk factors for CRGNB bloodstream infection. The random forest model has the best prediction ability, with AUROC being 0.86, followed by the XGBoost prediction model in bloodstream infection prediction. In the CRGNB prediction model analysis, the SVM and random forest model have higher area under the receiver operating characteristic curves, which are 0.88 and 0.87, respectively. CONCLUSIONS: The machine learning algorithm can accurately predict the occurrence of ICU-acquired bloodstream infection and identify whether CRGNB causes it once giving the order of blood culture.

Clonal Dissemination of Aeromonas hydrophila With Binary Carriage of bla KPC-2-Bearing Plasmids in a Chinese Hospital.

Dissemination of the Klebsiella pneumoniae carbapenemase (KPC)-encoding gene among Enterobacterales is common but relatively rare in Aeromonas spp. In this study, we characterized two KPC-2-producing Aeromonas hydrophila strains (Ah2101 and Ah2111), each isolated from a patient in different intensive care units (ICUs) of a Chinese hospital. Whole-genome sequencing (WGS) revealed simultaneous carriage of the bla KPC-2 and imiH genes, both of which encode high-level carbapenem resistance in these two A. hydrophila isolates. The two isolates were shown to be clonally related and each isolate harbored two distinguishable bla KPC-2-bearing plasmids, only one of which was transferrable to A. hydrophila, but not Escherichia coli EC600 via conjugation. The genetic element that contains bla KPC-2 in these two plasmids, namely ISKpn27-Δbla TEM-1-bla KPC-2-ISKpn6, was structurally identical, commonly detected in Enterobacterales, and associated with Tn3-based transposons. In addition, more than sixty putative genes that encode various virulence factors were identified in these two A. hydrophila isolates. This is the first study that reports clonal dissemination of carbapenem-resistant A. hydrophila strains carrying structurally different bla KPC-2-bearing plasmids. Further investigation is warranted to monitor the future transmission of bla KPC-2-bearing plasmids in A. hydrophila in clinical settings.

Adaptive iterative learning control for high-order nonlinear systems with random initial state shifts.

Aiming at the tracking problem for a class of high-order nonlinear systems with arbitrary initial state, this paper proposes different initial state shifts rectifying schemes for systems with different orders from the perspective of solving differential equations to ensure that the systems achieve complete tracking over the specified interval. This method relaxes the requirement of initial positioning in iterative learning control, and solves the problem of iterative learning control for high-order nonlinear systems with arbitrary initial state error. The theoretical analysis shows that the proposed schemes can make all signals in the system bounded, and ensure that the tracking error in the preset interval tends to zero as the number of iterations increases. When designing the controller, the arctangent function is used to avoid flutter of the control signal and related variables. The final simulations verify the effectiveness of the proposed algorithms.

Differential expression of circular RNAs in plasma exosomes from patients with ankylosing spondylitis.

Exosomes are being extensively studied as a source of valuable new biomarkers. The underlying mechanism of ankylosing spondylitis (AS) may include changes in the circular RNAs (circRNAs) of exosomes. However, there is a lack of reports on the role of exosomal cirRNAs in the plasma of patients with AS. We isolated exosomes from the plasma of patients with AS and healthy individuals (controls). Subsequently, we investigated the circRNA profiles of the exosomes via high-throughput RNA sequencing and identified 56 differentially expressed circRNAs in the exosomes of patients with AS compared with those of the healthy controls. Gene Ontology demonstrated that the differentially expressed circRNAs were mainly involved in the negative regulation of the activity of the transcription factor nuclear factor-κB and bone remodelling that is potentially related to AS. Kyoto Encyclopedia Genes and Genome demonstrated that the most highly AS-correlated pathways that were identified were 'notch signalling pathway' and those primarily involved with 'cholinergic synapse'. Finally, we validated five differentially expressed circRNAs using quantitative real-time polymerase chain reaction and predicted their potential functions through the circRNA-miRNA-mRNA network. Our study is the first to report changes in exosomal circRNAs from plasma samples of patients with AS, and provide novel targets for further investigation of molecular mechanisms and potential intervention therapy targets of AS.

Convergence of carbapenem resistance and hypervirulence in a highly-transmissible ST11 clone of K. pneumoniae: An epidemiological, genomic and functional study.

Co-occurrence of hypervirulence and KPC-2 carbapenem resistant phenotypes in a highly-transmissible ST11 clone ofKlebsiella pneumoniae has elicited deep concerns from public health stand point. To address this puzzle, we conducted a large-scale epidemiological, clinical and genomic study of K. pneumonia ST11 clones with both hypervirulence and carbapenem resistance in two tertiary hospitals in Zhejiang province. Most of the patients (15/23) were diagnosed with exclusively carbapenem-resistant K. pneumoniae (CRKP) infections. Ten death cases were reported, some of which are due to the failure of antibiotic therapies. As a result, we identified one new rare sequence types (ST449) to KPC-2-producing CRKP, in addition to the dominant ST11. These clinical isolates of K. pneumoniae are multi-drug resistant and possess a number of virulence factors. Experimental infections of wax moth larvae revealed the presence of hypervirulence at varied level, suggesting the complexity in bacterial virulence factors. However, plasmid curing assays further suggested that the rmpA2-virulence plasmid is associated with, but not sufficient for neither phenotypic hypermucoviscosity nor virulence of K. pneumoniae. Intriguingly, all the rmpA2 genes were found to be inactive due to genetic deletion. In total, we reported 21 complete plasmid sequences comprising 13 rmpA2-positive virulence plasmids and 8 blaKPC-2-harboring resistance plasmids. In addition to the prevalent pLVKP-like virulence plasmid variants (~178kb), we found an unexpected diversity among KPC-2-producing plasmids whose dominant form is IncFII-IncR type (~120kb), rather than the previously anticipated version of ~170kb. These findings provide an updated snapshot of convergence of hypervirulence and carbapenem resistance in ST11 K. pneumoniae.

Early use of polymyxin B reduces the mortality of carbapenem-resistant Klebsiella pneumoniae bloodstream infection.

Polymyxin B is one of the last resort option for carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infection in China. Therefore, the timing of administration of polymyxin is frequently delayed. We collected 40 cases of CRKP bloodstream infections (BSIs) treated with combinations based on polymyxin B over 30 months. The primary outcome, 30-day mortality rate, was 52.5% (21/40). Early administration of polymyxin B is meant to administer the drug within 48h of diagnosing bacteremia. Delayed administration was considered when polymyxin B was administered after 48h of bacteremia onset. Polymyxin B duration and total dosages were similar in the two groups (11.57 days versus 11.76 days, p=0.919; 1306.52mg versus 1247.06mg, p=0.711). Compared with delayed administration, early use of polymyxin B-based combination therapy had a significant increase in the rate of bacterial clearance (65.22% versus 29.41%, p=0.025; OR=0.533) and decreased 30-day mortality (39.13% versus 70.59%, p=0.045; OR=0.461) and overall mortality (43.48% versus 82.35%, p=0.022; OR=0.321).

Early use of polymyxin B reduces the mortality of carbapenem-resistant Klebsiella pneumoniae bloodstream infection

ABSTRACT Polymyxin B is one of the last resort option for carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infection in China. Therefore, the timing of administration of polymyxin is frequently delayed. We collected 40 cases of CRKP bloodstream infections (BSIs) treated with combinations based on polymyxin B over 30 months. The primary outcome, 30-day mortality rate, was 52.5% (21/40). Early administration of polymyxin B is meant to administer the drug within 48 h of diagnosing bacteremia. Delayed administration was considered when polymyxin B was administered after 48 h of bacteremia onset. Polymyxin B duration and total dosages were similar in the two groups (11.57 days versus 11.76 days, p = 0.919; 1306.52 mg versus 1247.06 mg, p = 0.711). Compared with delayed administration, early use of polymyxin B-based combination therapy had a significant increase in the rate of bacterial clearance (65.22% versus 29.41%, p = 0.025; OR = 0.533) and decreased 30-day mortality (39.13% versus 70.59%, p = 0.045; OR = 0.461) and overall mortality (43.48% versus 82.35%, p = 0.022; OR = 0.321).

The Hazard Perception for the Surrounding Shape of Warning Signs: Evidence From an Event-Related Potentials Study.

Surrounding shape is a very important component of warning signs. Unlike colors, signal words, and pictorials that can directly convey the surface meaning, the surrounding shapes of warning signs convey warning information somewhat obscurely. Most of the researchers who studied this topic investigated the individuals' hazard perception of the surrounding shapes of warning signs by using questionnaires. In addition, the scholars' points about the role of the surrounding shapes are inconsistent. This study, therefore, decided to use Event-Related Potentials (ERP) technology to explore the impact of the shapes on the perception of warning signs to find the evidences of the hazard perception of the shapes from the electrophysiological perspective. Using the Oddball paradigm, we found four components caused by different shapes of warning signs. Specifically, P200 amplitude characterizes the attraction to attention of surrounding shapes in the early automatic perception stage, the N300 components represented the emotional valance and arousal level, the P300 and the LPP connoted uneasy/unsafe information and reflected the inhibition strength on the uneasy/unsafe information. Experimental data indicated that the shape of UPRIGHT TRIANGLE had larger arousal strength and more negative valence than the shape of CIRCLE. People get stronger negative information from the UPRIGHT TRIANGLE shapes than from the CIRCLE. This finding might be helpful for designing the surrounding shapes of warning signs.

How Is the Neural Response to the Design of Experience Goods Related to Personalized Preference? An Implicit View.

Understanding the process by which consumers evaluate the designs of experience goods is critical for firms designing and delivering experience products. As the implicit process involved in this evaluation, and given the possible social desirability bias inherent to traditional methods of product design evaluation in certain conditions, neuroscientific methods are preferred to gain insight into the neural basis of consumers' evaluation of experience good designs. We here used event-related potentials (ERPs) and a revised go/no-go paradigm to investigate consumers' neural responses to experience good designs. Personalized product designs and neutral landscape pictures were randomly presented to 20 student participants; they were asked to view these product designs without making any decisions. The paired t-test and repeated-measures analysis of correlation showed that the P200 and late positive potential (LPP) elicited by the most-preferred experience good designs were significantly higher than that elicited by least-preferred designs, and the two ERP components were positively correlated with the personalized rating scores. Thus, P200 and LPP might be the early and late indices of consumers' evaluation of experience good designs, respectively, and may facilitate an understanding of the temporal course of this evaluation. Furthermore, these two ERP components can be used to identify consumers' preferences toward experience good designs. In addition, given the use of personalized experimental stimuli, these findings may help to explain why customized products are preferred by consumers.

A Secure Transmission Scheme Based on Artificial Fading for Wireless CrowdSensing Networks.

For secure transmission of low cost single antenna communication nodes in wireless crowdsensing networks under static channel, a physical layer communication scheme is proposed, where each digital modulated symbol is encrypted by a random key at the transmitter and decrypted with the same key at the receiver. The legal users exploit the synchronized chaotic sequence and the two-stage block interleaver to generate a complex random variable (random key), whereby its envelope obeys the Rayleigh distribution and its phase obeys the uniformly distribution. The modulated symbol is multiplied by the complex random variable (encryption) to imitate the Rayleigh fading of the channel at the transmitting end. The received symbol is divided by the identical complex random variable (decryption) to recover the transmitted message before the digital demodulation at the receiving end. Simulation results show that the bit error ratio (BER) performance of the legitimate users is consistent with the theoretical value of the Rayleigh fading channel, while the corresponding BER of the eavesdropper is too high (about 0.5) to intercept any information.

Acute Disseminated Talaromyces marneffei in An Immunocompetent Patient.

Talaromyces marneffei (also called Penicilliosis Marneffei or T. marneffei) is a rare fungal disease that is prevalent mainly in Southeast Asia and commonly seen in immunocompromised hosts. It was rarely observed in immunocompetent hosts. We report a case of acute disseminated T. marneffei in an immunocompetent patient in the non-prevalent region. This patient had never visited the endemic area. The patient experienced a persistent fever. Brain CT and magnetic resonance imaging (MRI) showed a mass in the right frontal with osteolytic damage. Excessive white blood cell (WBC) count and C-reactive protein content were observed. Antibiotics including meropenem and linezolid could not play an effect, and another two hard masses appeared in his right neck and front chest wall. The aspirates from the right frontal mass and bone marrow were cultured. The final diagnose of this infection was disseminated T. marneffei. After voriconazole treatment, all symptoms improved gradually. We present this case and aim to promote more clinicians and microbiologists in the non-endemic region to recognize this rare disease.

Invasive candidiasis in intensive care units in China: in vitro antifungal susceptibility in the China-SCAN study.

OBJECTIVES: The objectives of this study were to determine species distribution and in vitro antifungal susceptibility of Candida isolates identified in the multicentre China-SCAN study of invasive Candida infection (ICI) in intensive care units (ICUs) across China. METHODS: Candida isolates from patients in the China-SCAN study with documented ICI were evaluated by a central laboratory. Species were identified using chromogenic culture media or the API 20C AUX kit. Susceptibility to fluconazole, voriconazole, itraconazole, caspofungin and amphotericin B was determined using the CLSI broth microdilution method (M27-A3) and updated clinical breakpoints or epidemiological cut-off values. RESULTS: A total of 389 isolates from 244 patients were analysed. Species identified most frequently were Candida albicans (40.1%), Candida parapsilosis (21.3%), Candida tropicalis (17.2%) and Candida glabrata (12.9%). Rarer species such as Lodderomyces elongisporus and Candida ernobii were also identified. Fluconazole susceptibility was evident in 85.9% (134/156) of C. albicans, 62.7% (42/67) of C. tropicalis and 48.2% (40/83) of C. parapsilosis isolates. Susceptibility to voriconazole was ≥ 90% among all species. All isolates were susceptible to amphotericin B and caspofungin except C. glabrata [86.0% (43/50) susceptible to caspofungin]. Cross-resistance between fluconazole and voriconazole was observed for C. parapsilosis and C. glabrata. CONCLUSIONS: Although C. albicans was the predominant single species, non-albicans species constituted >50% of isolates. Fluconazole susceptibility was lower in most non-albicans species, indicating that fluconazole resistance should be closely monitored. Susceptibility to voriconazole, amphotericin B and caspofungin is encouraging. Differences between these data and those from other regions emphasize the importance of assessing regional variations.

[The antibacterial effect of cecropin B on pseudomonas aeruginosa infection of wounds in mice].

OBJECTIVE: To investigate the antibacterial effect of a particular antimicrobial peptide Cecropin B(CB) on Pseudomonas aeruginosa infection of wound in mice. METHODS: Thirty ICR mice were enrolled in the study, and the Pseudomonas aeruginosa infection model was reproduced by excision of the full layer of dorsal skin with an area of 1 cm x 1 cm. Then they were randomly divided into C ( control, n = 10, with wet compress of isotonic saline at 3 postinjury hour( PIH) ) , M (with hydropathic compress of 100 g/L mafenide at 3 PIH), A (with wet compress of 1 000 mg/L Cecropin B at 3 PIH) groups. The changes in body temperature and hemogram in each group were determined before and 4 days after injury. Quantitative examination were used to detect the quantity of bacteria in muscular tissue of the wounds, and the survival of the mice were observed on 4 post-injury day( PID). RESULTS: The wounds were moist with more exudation in C group,while that in other groups were dry without obvious exudation. The body temperature of the majority of the mice in each group were elevated, but the number of leucocytes in each group was lowered after operation. The quantity of bacteria in muscle in A group[ (42 +/- 50) CFU/g] was obviously lower than that in M group [(886+/-804) CFU/g, P <0.05] , and it was all obviously lower than that in C group[ (41 +/-28) x 10(5) CFU/g, P <0.01]. The number of surviving mice after 4 PID in C group was evidently smaller than that in A and M groups( P <0. 05). CONCLUSION: The cecropin B possesses obvious anti-bacterial effect on the Pseudomonas Aeruginosa infected wounds of ICR mice, and it can reduce the mortality.