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Fengjun Xia,1,2,* Xiaoyan Tao,2,3,* Haichen Wang,1,2 Jian Shui,4 Changhang Min,1,2 Yubing Xia,1,2 Jun Li,1,2 Mengli Tang,1,2 ZhaoJun Liu,1,2 Yongmei Hu,1,2 Huidan Luo,1,2 Mingxiang Zou1,2 1National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, People’s Republic of China; 2Department of Clinical Laboratory, Xiangya Hospital, Central South University, Changsha, 410008, People’s Republic of China; 3Department of Laboratory Medicine and Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People’s Republic of China; 4Department of Clinical Laboratory, Changsha Central Hospital, Changsha, 410008, People’s Republic of China*These authors contributed equally to this workCorrespondence: Mingxiang Zou, National Clinical Research Center for Geriatric Disorders, Department of Clinical Laboratory, Xiangya Hospital, Central South University, Changsha, Hunan Province, 410008, People’s Republic of China, Tel/Fax +86-7384327440, Email zoumingxiang@csu.edu.cnPurpose: As an under-explored biomaterial, bacterial biofilms have a wide range of applications in the green synthesis of nanomaterials. The biofilm supernatant of Pseudomonas aeruginosa PA75 was used to synthesize novel silver nanoparticles (AgNPs). BF75-AgNPs were found to possess several biological properties.Methods: In this study, we biosynthesized BF75-AgNPs using biofilm supernatant as the reducing agent, stabilizer, and dispersant and investigated their biopotential in terms of antibacterial, antibiofilm, and antitumor activities.Results: The synthesized BF75-AgNPs demonstrated a typical face-centered cubic crystal structure; they were well dispersed; and they were spherical with a size of 13.899 ± 4.036 nm. The average zeta potential of the BF75-AgNPs was − 31.0 ± 8.1 mV. The BF75-AgNPs exhibited strong antibacterial activities against the methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase Escherichia coli (ESBL-EC), extensively drug-resistant Klebsiella pneumoniae (XDR-KP), and carbapenem-resistant Pseudomonas aeruginosa (CR-PA). Moreover, the BF75-AgNPs had a strong bactericidal effect on XDR-KP at 1/2 × MIC, and the expression level of reactive oxygen species (ROS) in bacteria was significantly increased. A synergistic effect was observed when the BF75-AgNPs and colistin were used for the co-treatment of two colistin-resistant XDR-KP strains, with fractional inhibitory concentration index (FICI) values of 0.281 and 0.187, respectively. Furthermore, the BF75-AgNPs demonstrated a strong biofilm inhibition activity and mature biofilm bactericidal activity against XDR-KP. The BF75-AgNPs also exhibited a strong antitumor activity against melanoma cells and low cytotoxicity against normal epidermal cells. In addition, the BF75-AgNPs increased the proportion of apoptotic cells in two melanoma cell lines, and the proportion of late apoptotic cells increased with BF75-AgNP concentration.Conclusion: This study suggests that BF75-AgNPs synthesized from biofilm supernatant have broad prospects for antibacterial, antibiofilm, and antitumor applications.Graphical Abstract: Keywords: multidrug resistant, green synthesis, colistin, metallic silver, melanoma

Automatic detection and classification of road conditions are critical for the timely maintenance and repair of road surfaces. Aiming at the problems of single detection type, low detection efficiency, the low resolution of detection objects, and difficult detection of small object features in the road disease detection scene, this paper proposes an improved YOLOv5s road disease detection algorithm, YOLOv5s-DSG. First, optimize the depth and width of the network structure to reduce the impact on road damage image detection performance. Secondly, the Ghost module replaces the traditional convolution to reduce the number of model parameters, making the model lightweight and improving the detection rate. Finally, the Space-to-depth-Conv module is introduced to adapt to low-resolution and small object detection tasks. A large number of experiments on datasets such as Road Damage Dataset 2022 show that the average accuracy of the improved model at low resolution 640×640 is 1.1% higher than that of the original model, and the FPS is increased from 85 to 90; when the resolution is reduced to 480×480, the average accuracy remains the same and the FPS increases to 93. Compared with existing algorithms, it has apparent advantages in road comprehensive disease detection and classification.

Background The prevalence of multidrug-resistant hypervirulent K. pneumoniae (MDR-hvKP) has gradually increased. It poses a severe threat to human health. However, polymyxin-resistant hvKP is rare. Here, we collected eight polymyxin B-resistant K. pneumoniae isolates from a Chinese teaching hospital as a suspected outbreak. Results The minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. HvKP was identified by detecting virulence-related genes and using a Galleria mellonella infection model. Their resistance to serum, growth, biofilm formation, and plasmid conjugation were analyzed in this study. Molecular characteristics were analyzed using whole-genome sequencing (WGS) and mutations of chromosome-mediated two-component systems pmrAB and phoPQ, and the negative phoPQ regulator mgrB to cause polymyxin B (PB) resistance were screened. All isolates were resistant to polymyxin B and sensitive to tigecycline; four were resistant to ceftazidime/avibactam. Except for KP16 (a newly discovered ST5254), all were of the K64 capsular serotype and belonged to ST11. Four strains co-harbored blaKPC-2, blaNDM-1, and the virulence-related genes prmpA, prmpA2, iucA, and peg344, and were confirmed to be hypervirulent by the G. mellonella infection model. According to WGS analysis, three hvKP strains showed evidence of clonal transmission (8–20 single nucleotide polymorphisms) and had a highly transferable pKOX_NDM1-like plasmid. KP25 had multiple plasmids carrying blaKPC-2, blaNDM-1, blaSHV-12, blaLAP-2, tet(A), fosA5, and a pLVPK-like virulence plasmid. Tn1722 and multiple additional insert sequence-mediated transpositions were observed. Mutations in chromosomal genes phoQ and pmrB, and insertion mutations in mgrB were major causes of PB resistance. Conclusions Polymyxin-resistant hvKP has become an essential new superbug prevalent in China, posing a serious challenge to public health. Its epidemic transmission characteristics and mechanisms of resistance and virulence deserve attention.

CN-105 is an IV, apolipoprotein E-mimetic pentapeptide. Preclinical studies have reported that CN-105 effectively down-regulates neuroinflammatory responses in microglia and mitigates neuronal excitotoxicity following acute brain injury. The CN-105 Phase I and II trials that have been done in the United States have demonstrated that CN-105 was well tolerated in US participants. Thus, the main objective of the present Phase I study was to investigate the tolerability and pharmacokinetic (PK) profiles of CN-105 in healthy Chinese participants.This randomized, double-blind, placebo-controlled, dose-escalation study was performed in healthy participants using sequential 30-minute IV administration of single and multiple doses of CN-105 (four times daily for 13 doses). Forty volunteers were randomly assigned, in an 8:2 ratio, to one of four dosing groups, receiving either CN-105 (0.03, 0.1, 0.3, or 1 mg/kg), or placebo. Serial blood samples were collected for the measurement of plasma concentrations of CN-105. Tolerability was also assessed.After single-dose administration, the plasma CN-105 concentration rapidly reached the peak by the end of infusion. The mean elimination half-life of CN-105 ranged from 2.3 to 3.6 hours. During single- and multiple-dosing paradigms, exposure to CN-105 (AUC) exhibited linear dependency on dose. Steady state was reached by the fourth dose, with minimal accumulation. The PK properties of CN-105 with single and multiple dosing were comparable to those observed in US participants. CN-105 was generally well tolerated in Chinese participants. A total of 13 adverse events were reported in 30% of subjects (12/40) at the 0.03 mg/kg (6/8), 0.1 mg/kg (1/8), 0.3 mg/kg (2/8), 1 mg/kg (0/8) doses and with placebo (3/8). All adverse events were mild or moderate in severity and self-limited, with no dose relationship observed.CN-105 was well tolerated in these healthy Chinese participants at doses of 0.1 to 1 mg/kg with single and multiple IV administrations. The PK characteristics of CN-105 were comparable among Chinese and Western subjects. A Phase II study in patients with intracranial hemorrhage is being planned in China.gov identifiers: NCT02670824 and NCT03168581; Chinese Clinical Trial Registration identifier: CTR20202397.

Haichen Wang,1,2 Jia Li,2,3 Changhang Min,1,2 Fengjun Xia,1,2 Mengli Tang,1,2 Jun Li,1,2 Yongmei Hu,1,2 Mingxiang Zou1,2 1National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, People’s Republic of China; 2Department of Clinical Laboratory, Xiangya Hospital, Central South University, Changsha, Hunan Province, People’s Republic of China; 3Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of ChinaCorrespondence: Mingxiang Zou, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 41008, People’s Republic of China, Tel/Fax +86 7384327440, Email zoumingxiang@csu.edu.cnPurpose: Due to the extensive consumption of silver-containing compound, silver resistance spreads among gram-negative pathogens and is regarded as a great public problem. In this study, we investigated silver resistance mechanisms and antibiotic resistance genes co-harbored with sil operon among gram-negative pathogens isolated from wound samples.Methods: A total of 193 strains of gram-negative pathogens were collected from wound samples between 2018 and 2020 in Xiangya hospital. Silver resistance was obtained by broth microdilution method. The silver resistance mechanisms and the prevalence, genetic environments, and coexistence with antibiotic resistance genes of sil operon were investigated by polymerase chain reaction (PCR) and whole genome sequencing (WGS).Results: Among 193 strains, nine strains (4.7%) were resistant to Ag+ and assigned to the following species: Klebsiella pneumoniae (n = 5) and Enterobacter hormaechei (n = 4). WGS confirmed that 24 strains carried the entire sil operon, including the four Ag+-resistant E. hormaechei and 20 Ag+-susceptible strains, while PCR failed to detect some sil genes, especially silE, due to sequence variations. In seven strains, Tn7 transposon was identified in the upstream of sil operon. Spontaneous mutants resistant to Ag+ were induced in 15 out of 20 Ag+-susceptible strains, including K. pneumoniae strains belonged to high-risk groups (ST11 and ST15). The sil-positive strains harbored various antibiotic resistance genes, including blaESBL and blaApmC. WGS revealed that a single mutation in cusS gene and loss of major porins conferred silver resistance in the five K. pneumoniae strains.Conclusion: Our findings emphasize the cryptic silver resistance is prevalent among Enterobacteriaceae with sil operon or with the combination of cus operon and major porin loss and increase the understanding of the prevalence of sil operon with antibiotic resistance genes, especially blaESBL and blaApmC.Keywords: silver resistance, gram negative pathogen, sil operon, antibiotic resistance gene, whole-genome sequencing

The aim of this study was to investigate the clinical features, distribution and antimicrobial susceptibility of Nocardia species isolated from pulmonary nocardiosis cases in tertiary hospital in China. The species were collected from January 1, 2018 to May 31, 2019 and identified using MALDI-TOF MS or PCR. Antimicrobial susceptibility testing was performed using the broth microdilution method. Within the 44 Nocardia species, N. farcinica was the most frequently identified species (n = 36), followed by N. nova (n = 5), N. otitidiscaviarum (n = 1), N. cyriacigeorgica (n = 1), and N. transvalensis (n = 1). The top three predisposing factors of pulmonary nocardiosis were chronic obstructive pulmonary disease (45.5%), hypertension (34.1%), and tuberculosis (31.8%). All 44 Nocardia strains were susceptible to amikacin, trimethoprim / sulfamethoxazole, and linezolid. The resistance rates of Nocardia to amoxicillin-clavulanic acid, ciprofloxacin, clarithromycin, ceftriaxone, tobramycin, and imipenem were 4.5%, 9.1%, 79.5%, 72.7%, 63.6%, and 38.6%, respectively. Two Nocardia strains had decreased sensitivity to trimethoprim / sulfamethoxazole. In conclusion, N. farcinica was the most frequently isolated Nocardia species in the First Hospital of Changsha. All isolated clinical Nocardia strains showed susceptible to amikacin, trimethoprim / sulfamethoxazole, and linezolid, suggesting that these drugs can be primary therapeutic choices for treating Nocardia infections.

The aim of this study was to analyze the role of blood biomarkers regarding preoperative inflammation and coagulation in predicting the postoperative in-hospital mortality of patients with type A acute aortic dissection (AAD). A total of 206 patients with type A AAD who had received surgical treatment were enrolled in this study. Patients were divided into two groups: the death group (28 patients who died during hospitalization) and the survival group (178 patients). Peripheral blood samples were collected before anesthesia induction. Preoperative levels of D-dimer, fibrinogen (FIB), platelet (PLT), white blood cells (WBC) and neutrophil (NEU) were compared between the two groups. Univariable and multivariable logistic regression analysis were utilized to identify the independent risk factors for postoperative in-hospital deaths of patients with type A AAD. Receiver operating characteristic (ROC) curve were used to analyze the predictive value of these indices in the postoperative in-hospital mortality of the patients. Univariable logistic regression analysis showed that the P values of the five parameters including D-dimer, FIB, PLT, WBC and NEU were all less than 0.1, which may be risk factors for postoperative in-hospital deaths of patients with type A AAD. Further multivariable logistic regression analysis indicated that higher preoperative D-dimer and WBC levels were independent risk factors for postoperative in-hospital mortality of patients with type A AAD. ROC curve analysis indicated that application of combining FIB and PLT could improve accuracy in prediction of postoperative in-hospital mortality in patients with type A AAD. Both preoperative D-dimer and WBC in patients with type A AAD may be used as independent risk factors for the postoperative in-hospital mortality of such patients. The combination of FIB and PLT may improve the accuracy of clinical prognostic assessment.

To investigate the relationship of biofilm-forming ability of (PA) with swimming motility, twitching motility and virulence gene distribution. A total of 192 clinical isolates of PA were collected consecutively. Microtiter plate method was used to evaluate the ability to form biofilm. The swimming and twitching motilities were detected by plate method. Polymerase chain reaction (PCR) was used to detect virulence genes. Of the 192 PA clinical isolates, 186 (96.9%) showed biofilm-forming ability. Among them, 36 isolates showed weak biofilm-forming ability, 84 exhibited moderate biofilm-forming ability and 66 showed strong biofilm-forming ability. The diameters of the swimming ring for PA with none biofilm-forming ability, weak biofilm-forming ability, moderate biofilm-forming ability, strong biofilm-forming ability were (9.12±6.76), (18.42±7.51), (19.10±4.77) and respectively. The diameters of the twitching ring for PA in above groups were (8.38±1.50), (17.21±7.42), (18.49±5.62) and respectively. The swimming motility and twitching motility of none biofilm-forming ability group were weaker than biofilm-forming ability groups (all

Background. The risk of cognitive impairment in patients with atrial fibrillation is significantly increased. Its occurrence may be related to blood hypercoagulable state and immune inflammatory reaction. Platelets can mediate immune inflammatory response, but there is no evidence about the relationship between platelet count and cognitive function in patients with atrial fibrillation. Purpose. To explore whether there is a certain correlation between platelet count and cognitive function in patients with atrial fibrillation. Methods. A cross-sectional study was conducted in a single center in China, including 254 patients with atrial fibrillation. Cognitive function assessment and clinical and laboratory examinations were performed on all participants. After adjusting the related confounding factors, the relationship between platelet count and cognitive function was analyzed. Results. A total of 254 subjects with an average age of 59.71 ± 11.14 years were included. The average platelet count was 208.15 ± 68.30, and the average score of cognitive function was 19.29 ± 6.78. Result of fully adjusted binary logistic regression showed platelet count was negatively associated with the cognitive function score after adjusting confounders (hazard ratio (HR) = 0.000, 95%CI −0.01, 0.01). A nonlinear relationship was detected between platelet count and the cognitive function score, whose point was 230. The effect sizes and the confidence intervals of the left and right sides of the inflection point were 0.03 (0.01–0.05, P for nonlinearity = 0.011) and −0.03 (−0.05–0.00, P for nonlinearity = 0.023), respectively. Conclusion. Platelets have a nonlinear relationship with cognitive function in patients with atrial fibrillation. This finding suggests that, in patients with atrial fibrillation, platelets should be maintained at about 230.

BackgroundIntracerebral hemorrhage (ICH) is a devastating form of cerebrovascular disease for which there are no approved pharmacological interventions that improve outcomes. Apolipoprotein E (apoE) has emerged as a promising therapeutic target given its neuroprotective properties and ability to modify neuroinflammatory responses. We developed a 5-amino acid peptide, CN-105, that mimics the polar face of the apoE helical domain involved in receptor interactions, readily crosses the blood-brain barrier, and improves outcomes in well-established preclinical ICH models. In the current study, we investigated the therapeutic potential of CN-105 in translational ICH models that account for hypertensive comorbidity, sex, species, and age.MethodsIn three separate experiments, we delivered three intravenous doses of CN-105 (up to 0.20 mg/kg) or vehicle to hypertensive male BPH/2J mice, spontaneously hypertensive female rats, or 11-month old male mice within 24-hours of ICH. Neuropathological and neurobehavioral outcomes were determined over 3, 7, and 9 days, respectively.ResultsIn spontaneously hypertensive male mice, there was a significant dose-dependent effect of CN-105 on vestibulomotor function at 0.05 and 0.20 mg/kg doses (p < 0.05; 95% CI: 0.91 – 153.70 and p < 0.001; 95% CI: 49.54 – 205.62), while 0.20 mg/kg also improved neuroseverity scores (p < 0.05; 95% CI: 0.27 – 11.00) and reduced ipsilateral brain edema (p < 0.05; 95% CI:−0.037 –−0.001). In spontaneously hypertensive female rats, CN-105 (0.05 mg/kg) had a significant effect on vestibulomotor function (p < 0.01; η2= 0.093) and neuroseverity scores (p < 0.05; η2= 0.083), and reduced contralateral edema expansion (p < 0.01; 95% CI:−1.41 –−0.39). In 11-month old male mice, CN-105 had a significant effect on vestibulomotor function (p < 0.001; η2= 0.111) but not neuroseverity scores (p > 0.05; η2= 0.034).ConclusionsAcute treatment with CN-105 improves outcomes in translational ICH models independent of sex, species, age, or hypertensive comorbidity.

The role of kallikrein-related peptidase 5 (KLK5) has been studied in several diseases, including skin and ovarian cancers. However, its role in cervical cancer remains unclear, particularly in regulating the radiation resistance and growth of cervical cancer cells. Radiation resistance of cervical cancer is associated with local recurrence, distant metastasis, and reduced survival.We first analyzed radiotherapy-naive samples and relevant clinical data from patients with cervical cancer who received radiotherapy without surgery or other antitumor treatment from 2014 to 2016. Subsequently, biopsied tissues, in vitro cells, and transplanted tumors in nude mice were investigated.Gene sequencing and clinical data analysis showed that KLK5 overexpression was associated with a poor prognosis post-radiotherapy. In in vitro cell and tumor transplantation experiments, KLK5 overexpression significantly increased radiation resistance. However, downregulating KLK5 expression increased radiosensitivity.Our results confirm that KLK5 is vital to the radioresistance of cervical cancer, and provide a new target and marker for the treatment of radioresistance in cervical cancer.

Background Acinetobacter baumannii has traditionally been considered an opportunistic pathogen with low virulence. In this study, we characterized the carbapenem-resistant hypervirulent A. baumannii (CR-hvAB) stains isolated from our hospital in mid-south region of China. Results Blood samples collected between January 2017 and May 2019 were used for virulence experiments and biofilm assays of individual carbapenem-resistant A. baumannii (CR-AB) strains, performed using a Galleria mellonella infection model and crystal violet staining method, respectively. CR-AB isolates that induced high mortality in the G. mellonella infection model were subjected to genotyping, susceptibility testing, and clinical data analysis, and the genetic characterization of these isolates was performed by whole-genome sequencing (WGS). Among the 109 CR-AB clinical strains, the survival rate of G. mellonella larvae infected with 7 (6.4%) CR-AB isolates (number of strains with mortality of 0, 10 and 20% was 4, 1, and 2, respectively), was significantly lower than that of A. baumannii ATCC 19606 (100.0%) and the remaining CR-AB isolates (> 80.0%). Consistent with these results, patients infected with these seven isolates had an average 7-day mortality rate of 42.9%, suggesting that the isolates were CR-hvAB. These seven isolates belonged to four sequence types (STs): ST457, ST195, ST369, and ST2088 (a new ST), and mainly ST457 (n = 4). The results of the biofilm study showed that eight strains had powerful biofilm ability (strong [n = 1] and moderate [n = 7] biofilm producers) including these seven CR-hvAB isolates. Conclusions CR-hvAB isolates that induced a high mortality rate were cloned in our hospital, most of which belonged to ST457; thus, monitoring of these strains, particularly ST457, should be strengthened in the future. Meanwhile, A. baumannii, which was isolated from blood specimens and found to powerful biofilm-forming ability, is a probable hvAB isolate.

BackgroundAppropriately modulating inflammation after traumatic brain injury (TBI) may prevent disabilities for the millions of those inflicted annually. In TBI, cellular mediators of inflammation, including macrophages and microglia, possess a range of phenotypes relevant for an immunomodulatory therapeutic approach. It is thought that early phenotypic modulation of these cells will have a cascading healing effect. In fact, an anti-inflammatory, “M2-like” macrophage phenotype after TBI has been associated with neurogenesis, axonal regeneration, and improved white matter integrity (WMI). There already exist clinical trials seeking an M2-like bias through mesenchymal stem/stromal cells (MSCs). However, MSCs do not endogenously synthesize key signals that induce robust M2-like phenotypes such as interleukin-4 (IL-4).MethodsTo enrich M2-like macrophages in a clinically relevant manner, we augmented MSCs with synthetic IL-4 mRNA to transiently express IL-4. These IL-4 expressing MSCs (IL-4 MSCs) were characterized for expression and functionality and then delivered in a modified mouse TBI model of closed head injury. Groups were assessed for functional deficits and MR imaging. Brain tissue was analyzed through flow cytometry, multi-plex ELISA, qPCR, histology, and RNA sequencing.ResultsWe observed that IL-4 MSCs indeed induce a robust M2-like macrophage phenotype and promote anti-inflammatory gene expression after TBI. However, here we demonstrate that acute enrichment of M2-like macrophages did not translate to improved functional or histological outcomes, or improvements in WMI on MR imaging. To further understand whether dysfunctional pathways underlie the lack of therapeutic effect, we report transcriptomic analysis of injured and treated brains. Through this, we discovered that inflammation persists despite acute enrichment of M2-like macrophages in the brain.ConclusionThe results demonstrate that MSCs can be engineered to induce a stronger M2-like macrophage response in vivo. However, they also suggest that acute enrichment of only M2-like macrophages after diffuse TBI cannot orchestrate neurogenesis, axonal regeneration, or improve WMI. Here, we also discuss our modified TBI model and methods to assess severity, behavioral studies, and propose that IL-4 expressing MSCs may also have relevance in other cavitary diseases or in improving biomaterial integration into tissues.

Over the last few decades, increasing evidence demonstrates that the neuroinflammatory response is a double-edged sword. Although overly robust inflammatory responses may exacerbate secondary tissue injury, inflammatory processes are ultimately necessary for recovery. Traditional drug discovery often relies on reductionist approaches to isolate and modulate specific intracellular pathways believed to be involved in disease pathology. However, endogenous brain proteins are often pleiotropic in order to regulate neuroinflammation and recovery mechanisms. Thus, a process of “backward translation” aims to harness the adaptive properties of endogenous proteins to promote earlier and greater recovery after acute brain injury. One such endogenous protein is apolipoprotein E (apoE), the primary apolipoprotein produced in the brain. Robust preclinical and clinical evidence demonstrates that endogenous apoE produced within the brain modulates the neuroinflammatory response of the acutely injured brain. Thus, one innovative approach to improve outcomes following acute brain injury is administration of exogenous apoE-mimetic drugs optimized to cross the blood–brain barrier. In particular, one promising apoE mimetic peptide, CN-105, has demonstrated efficacy across a wide variety of preclinical models of brain injury and safety and feasibility in early-phase clinical trials. Preclinical and clinical evidence for apoE’s neuroprotective effects and downregulation of neuroinflammatory and the resulting translational therapeutic development strategy for an apoE-based therapeutic are reviewed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13311-020-00858-x) contains supplementary material, which is available to authorized users.

Background Small colony variants (SCVs) of Staphylococcus aureus (S. aureus) frequently lead to chronic and recurrent infections, but they are always ignored and there are few researches on their clinical isolates. We intended to investigate the prevalence and characteristics of S. aureus SCVs. Methods None‐duplicated S. aureus strains isolated from wound samples were collected from January 2018 to December 2020. The characteristics (i.e. colony morphology, growth rate, coagulase, biofilm formation, and pathogenic characteristics), antimicrobial susceptibilities, and resistance mechanisms of SCVs were also investigated. The genetic background of SCVs was analyzed through staphylococcal protein A (SPA) typing, sequence typing, and pulse field gel electrophoresis (PFGE). Results Three SCVs were screened from 278 S. aureus strains (1.1%). They formed pinpoint white colonies on blood agar plates with weak hemolysis. The reproduction speed in liquid medium was very slow for SCVs strains. The coagulase weakened or disappeared, and the ability to form biofilm varied greatly. Only slight inflammation was triggered when wound infected. The SPA typing was t2592, t233, and t023, and the sequence typing was ST88, ST239, and ST965, respectively. The PFGE revealed three SCVs were singletons. Conclusions The rate of SCVs in wound sample is low in our hospital, and the formation is associated with the usage of antimicrobial. SCVs grow slowly, and their colony morphology and biochemical characteristics are significantly different from classic S. aureus. SCVs may cause chronic infection and weak inflammation. SCVs form in resistant or susceptible strains, and there is no clonal epidemic in this hospital., Through investigating the epidemiology and characteristics of small colony variants (SCVs) of S. aureus in wound specimens, here we found that the formation of SCVs is very rare and closely related to the usage of antibiotics. At the same time, the formation of SCVs may not be limited to specific resistance types and genetic types. Therefore, clinical laboratories should pay more attention to SCVs to facilitate effective treatment of SCVs infection.

The development of novel therapies targeting cardiomyocyte pyroptosis is needed for myocardial infarction (MI). The current study sought to analyze the role and mechanism of M2 macrophage-derived extracellular vesicles (M2-EVs) in cardiomyocyte pyroptosis after MI. M2 macrophages were induced, and M2-EVs were separated and characterized. A mouse model of MI was successfully established, followed by an assessment of myocardial injury and cardiomyocyte pyroptosis. An in vitro cell model was established, followed by a comprehensive evaluation of cell viability and pyroptosis. The binding relationships of miR-378a-3p and ELAVL1 [human antigen R (HuR)], HuR, and NLR family pyrin domain containing 3 (NLRP3) were analyzed. A functional rescue experiment was designed to validate the role of HuR. After M2-EV treatment, the cardiac functions of mice with MI were restored, the myocardial injury was attenuated and cardiomyocyte pyroptosis was reduced. In vitro, M2-EVs suppressed hypoxic cell injury and pyroptosis. Mechanistically, M2-EVs delivered miR-378a-3p into cardiomyocytes to upregulate miR-378a-3p expression and inhibit ELAVL1 (HuR) expression and transport of HuR to the cytoplasm, thus destabilizing NLRP3 and inhibiting activation of the NLRP3/Caspase-1/GSDMD pathways. Overexpression of HuR inhibited the protective effect of M2-EVs in cardiomyocytes. Overall, our findings showed that M2-EV-enveloped miR-378a-3p inhibited HuR expression and HuR translocation to the cytoplasm to destabilize NLRP3 and block activation of the NLRP3/Caspase-1/GSDMD pathways, thereby attenuating cardiomyocyte pyroptosis.

OBJECTIVE: To investigate the relationship of biofilm-forming ability of Pseudomonas aeruginosa(PA) with swimming motility, twitching motility and virulence gene distribution. METHODS: A total of 192 clinical isolates of PA were collected consecutively. Microtiter plate method was used to evaluate the ability to form biofilm. The swimming and twitching motilities were detected by plate method. Polymerase chain reaction (PCR) was used to detect virulence genes. RESULTS: Of the 192 PA clinical isolates, 186 (96.9%) showed biofilm-forming ability. Among them, 36 isolates showed weak biofilm-forming ability, 84 exhibited moderate biofilm-forming ability and 66 showed strong biofilm-forming ability. The diameters of the swimming ring for PA with none biofilm-forming ability, weak biofilm-forming ability, moderate biofilm-forming ability, strong biofilm-forming ability were (9.12±6.76), (18.42±7.51), (19.10±4.77) and (17.80±5.27) mm, respectively. The diameters of the twitching ring for PA in above groups were (8.38±1.50), (17.21±7.42), (18.49±5.62) and (20.44±6.43) mm, respectively. The swimming motility and twitching motility of none biofilm-forming ability group were weaker than biofilm-forming ability groups (all P

Background Carbapenem-resistant Enterobacterales (CRE) are rapidly increasing worldwide in last two decades and lead few antibiotics for treatment. The molecular epidemiology of CRE in China was investigated to provide basis for clinical rational use of antibiotics and prevent its spread. Methods All CRE isolates in this study were collected from 11 hospitals from October 2015 to July 2018. The isolates were subjected to antimicrobial susceptibility tests, PCR molecular identification, pulsed-field gel electrophoresis, and multilocus sequence typing. Results Among the 399 CRE isolates, 51.6% (206/399) harbored carbapenemase genes. Three carbapenemase genes were detected, namely blaKPC-2, blaNDM-1, and blaIMP at rates of 29.8% (119/399), 17.5% (70/399), and 4.0% (16/399), respectively. In Klebsiella pneumoniae (350) and Escherichia coli (26), blaKPC-2 (33.4%, 117/350) and blaNDM-1 (61.5%, 16/26) were the predominant genes. The most common genes in the CRE isolates were blaKPC (85.5%) and blaNDM-1 (76.5%) from adults and children, respectively. Particularly, ST11 K. pneumoniae with blaKPC-2 harbored by IncFII plasmids were distributed in both general and primary hospitals, suggesting a clonal transmission pattern at these sites. In addition, the clonal distribution of ST2407 K. pneumoniae with blaNDM-1 located on IncX3 plasmids and blaIMP-38-positive ST307 K. pneumoniae were detected in a children’s hospital. Conclusion The distribution of carbapenemase genes differed among strains and age groups. Multiple carbapenemase genes in the CRE strains were clonally disseminated in the tested regions mediated by multiple plasmids. Therefore, CRE monitoring should be increased and measures should be adopted to prevent its transmission.

Myocardial ischaemia-reperfusion injury (MIRI) is a main pathophysiologic change following CPB surgery. L-carnitine, a natural amino acid, is able to transport fatty acids for generating energy and has a protective effect on MIRI. We aim to investigate the protective effect of L-carnitine on MIRI in patients with rheumatic valvular heart disease (RVHD) performed CPB surgical operation and the underlying mechanism. In this study, patients were randomized to three groups. L-carnitine was added to the crystalloid cardioplegic solution for experimental group 1 (6 g/L) and experimental group 2 (12 g/L), whereas no L-carnitine was used in the control group. Our results showed that L-carnitine significantly attenuated myocardial injury after surgery in these patients. L-carnitine decreased serum markers of myocardial injury including CK-MB, cTnI, hs-cTnT and IMA. L-carnitine increased left ventricular ejection fraction (LVEF) but reduced wall motion score index (WMSI) after operation. L-carnitine also inhibited myeloperoxidase (MPO) activity and inflammatory cytokines in the myocardium of patients after unclamping the aorta. Additionally, L-carnitine increased levels of superoxide dismutase (SOD) and catalase (CAT) while decreased levels of malondialdehyde (MDA) and protein carbonyl content in the myocardium of patients after unclamping the aorta. Moreover, L-carnitine suppressed the activation of nuclear factor kappa B (NF-κB) and activated nuclear factor erythroid 2-related factor 2 (Nrf2). There was also no significant difference in these indices between two experimental groups after unclamping the aorta. Taken together, L-carnitine had a protective effect against CPB-induced MIRI in patients with RVHD, which might be related to its modulation of NF-κB and Nrf2 activities.