Acute pancreatitis (AP) is a prevalent acute gastrointestinal disease, which may be prevented and alleviated by probiotics. Bifidobacterium animalis subsp. lactis BB-12 (BB-12) is a widely studied probiotic strain; however, its specific effects in this context remain unexplored. In this study, we aimed to investigate the prophylactic and therapeutic effects of BB-12 in AP. Our findings revealed that BB-12 administration via gavage significantly reduced pathological pancreatic damage and serum amylase activity. Microbiome analysis showed that BB-12 treatment significantly increased the relative abundance of Ligilactobacillus and decreased that of Bilophila in the gut microbiota of mice with AP. Transcriptome analysis revealed that BB-12 mitigated the AP-induced dysregulation of several pathways, specifically attenuating the upregulation of the pancreatic secretion and ascorbate and aldarate metabolism pathways while reversing the downregulation of the ribosome, oxidative phosphorylation, and thermogenesis pathways. Spearman’s correlation analysis revealed a positive correlation between the abundances of Bilophila and ASF356 and serum amylase activity. Furthermore, the abundances of Bilophila and ASF356 were significantly correlated with BB-12-regulated pancreatic genes and were predominantly enriched in the ribosome pathway. In conclusion, BB-12 pretreatment alleviated AP, likely by regulating the abundance of intestinal Lactobacillus, Bilophila, and ASF356, as well as the pancreatic secretion, ascorbate and aldarate metabolism, oxidative phosphorylation, ribosome, and thermogenesis pathways.

Escherichia coli, a rod-shaped Gram-negative bacterium, is a significant causative agent of severe clinical bacterial infections. This study aimed to analyze the epidemiology of extended-spectrum β-lactamase (ESBL)-producing mcr-1 -positive E. coli in Shandong, China. We collected 668 non-duplicate ESBL-producing E. coli strains from clinical samples at Shandong Provincial Hospital between January and December 2018, and estimated their minimum inhibitory concentrations (MICs) using a VITEK® 2 compact system and broth microdilution. Next-generation sequencing and bioinformatic analyses identified the mcr-1 gene and other resistance genes in the polymyxin B-resistant strains. The conjugation experiment assessed the horizontal transfer capacity of the mcr-1 gene. Of the strains collected, 24 polymyxin B-resistant strains were isolated with a positivity rate of 3.59% and among the 668 strains, 19 clinical strains carried the mobile colistin resistance gene mcr-1, with a positivity rate of approximately 2.8%. All 19 clinical strains were resistant to ampicillin, cefazolin, ceftriaxone, ciprofloxacin, levofloxacin, and polymyxin B. Seventeen strains successfully transferred the mcr-1 gene into E. coli J53. All transconjugants were resistant to polymyxin B, and carried the drug resistance gene mcr-1. The 19 clinical strains had 14 sequence types (STs), with ST155 (n = 4) being the most common. The whole-genome sequencing results of pECO-POL-29_mcr1 revealed that no ISApl1 insertion sequences were found on either side of the mcr-1 gene. Our study uncovered the molecular epidemiology of mcr-1-carrying ESBL-producing E. coli in the region and suggested horizontal transmission mediated by plasmids as the main mode of mcr-1 transmission.

Abstract Objective To understand the prevalence and the drug resistance of the Staphylococcus aureus (S. aureus) isolates harboring Panton–Valentine leukocidin (PVL) gene in the Shandong Provincial Hospital in 2023. The clinical application values of white blood cell (WBC), C-reactive protein (CRP), and neutrophil-to-lymphocyte ratio (NLR) in the diagnosis of PVL-positive S. aureus infection were investigated. Methods 166 S. aureus isolates were separated from inpatients in the Shandong Provincial Hospital in 2023. We determined the presence of the mecA gene and genes encoding PVL using PCR, and the department distributions and drug resistance of the isolates were analyzed. Groups were grouped according to the mecA and PVL gene test results. Contemporaneous 100 subjects undergoing healthy physical examination were selected as the control group. The levels of WBC, CRP, and NLR of each group were collected, and the clinical application values of WBC, CRP, and NLR for PVL-positive S. aureus infection were compared. Results Among the 166 strains of S. aureus, 73 isolates were Methicillin-resistant S. aureus (MRSA). The prevalence of MRSA among inpatients in the Surgical Department, Internal Medicine Department, Intensive Care Unit (ICU), Emergency and Pediatric Department was 64.4%, 12.3%, 15.1%, 4.1% and 4.1%, respectively. PVL genes were detected in 88 strains of S. aureus, most of which were Methicillin-susceptible S. aureus (MSSA). The levels of WBC, CRP, and NLR increased significantly during S. aureus infection, and the level of NLR in the PVL-positive group was significantly higher than that in the PVL-negative group (Z= -2.13, P = 0.033). Still, the levels of WBC, and CRP were rarely different between the PVL-positive group and PVL-negative group. Conclusions This study analyzed the prevalence of S. aureus harboring the PVL gene in Shandong Provincial Hospital in 2023. Compared with WBC and CRP, NLR had a higher clinical application value for PVL-positive S. aureus, and NLR can be used as a screening indicator for PVL-positive S. aureus infection.

Background:Enterobacter cloacae complex (ECC), which includes major nosocomial pathogens, causes urinary, respiratory, and bloodstream infections in humans, for which colistin is one of the last-line drugs. Objective:This study aimed to analyse the epidemiology and resistance mechanisms of colistin-resistant Enterobacter cloacae complex (ECC) strains isolated from Shandong, China. Methods:Two hundred non-repetitive ECC strains were collected from a tertiary hospital in Shandong Province, China, from June 2020 to June 2022. Whole-genome sequencing and bioinformatics analyses were performed to understand the molecular epidemiology of the colistin-resistant ECC strains. The nucleotide sequences of heat shock protein (hsp60) were analyzed by using BLAST search to classify ECC. The gene expression levels of ramA, soxS, acrA, acrB, phoP, and phoQ were assessed using RT-qPCR. MALDI-TOF MS was used to analyse the modification of lipid A. Results:Twenty-three colistin-resistant strains were detected among the 200 ECC clinical strains (11.5%). The hsp60 cluster analysis revealed that 20 of the 23 ECC strains belonged to heterogeneous resistance clusters. Variants of mgrB, phoPQ, and pmrAB, particularly phoQ and pmrB, were detected in the 23 ECC strains. The soxS and acrA genes were significantly overexpressed in all 23 colistin-resistant ECC strains (P < 0.05). Additionally, all 23 ECC strains contained modified lipid A related to colistin resistance, which showed five ion peaks at m/z 1876, 1920, 1955, 2114, and 2158. Among the 23 ECC strains, 6 strains possessed a phosphoethanolamine (pETN) moiety, 16 strains possessed a 4-amino-4-deoxy-L-arabinose (-L-Ara4N) moiety, and one strain had both pETN and -L-Ara4N moieties. Conclusion:This study suggests that diverse colistin resistance existed in ECC, including unknown resistance mechanisms, exist in ECC. Mechanistic investigations of colistin resistance are warranted to optimise colistin use in clinical settings and minimise the emergence of resistance.

Carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) co-producing blaKPC and blaNDM poses a serious threat to public health. This study aimed to investigate the mechanisms underlying the resistance and virulence of CR-hvKP isolates collected from a Chinese hospital, with a focus on blaKPC and blaNDM dual-positive hvKP strains. Five CR-hvKP strains were isolated from a teaching hospital in China. Antimicrobial susceptibility and plasmid stability testing, plasmid conjugation, pulsed-field gel electrophoresis, and whole-genome sequencing (WGS) were performed to examine the mechanisms of resistance and virulence. The virulence of CR-hvKP was evaluated through serum-killing assay and Galleria mellonella lethality experiments. Phylogenetic analysis based on 16 highly homologous carbapenem-resistant K. pneumoniae (CRKP) producing KPC-2 isolates from the same hospital was conducted to elucidate the potential evolutionary pathway of CRKP co-producing NDM and KPC. WGS revealed that five isolates individually carried three unique plasmids: an IncFIB/IncHI1B-type virulence plasmid, IncFII/IncR-type plasmid harboring KPC-2 and IncC-type plasmid harboring NDM-1. The conjugation test results indicated that the transference of KPC-2 harboring IncFII/IncR-type plasmid was unsuccessful on their own, but could be transferred by forming a hybrid plasmid with the IncC plasmid harboring NDM. Further genetic analysis confirmed that the pJNKPN26-KPC plasmid was entirely integrated into the IncC-type plasmid via the copy-in route, which was mediated by TnAs1 and IS26. KPC-NDM-CR-hvKP likely evolved from a KPC-2-CRKP ancestor and later acquired a highly transferable blaNDM-1 plasmid. ST11-KL64 CRKP exhibited enhanced plasticity. The identification of KPC-2-NDM-1-CR-hvKP highlights the urgent need for effective preventive strategies against aggravated accumulation of resistance genes.

Purpose This study aimed to characterise the whole-genome structure of two clinical Klebsiella pneumoniae strains co-harbouring mcr-8.1 and tmexCD1-toprJ1 , both resistant to colistin and tigecycline. Methods K. pneumoniae strains TGC-02 (ST656) and TGC-05 (ST273) were isolated from urine samples of different patients hospitalised at separate times in 2021. Characterisation involved antimicrobial susceptibility testing (AST), conjugation assays, whole-genome sequencing (WGS), and bioinformatics analysis. Comparative genomic analysis was conducted on mcr-8.1-carrying and tmexCD1-toprJ1 -carrying plasmids. Results Both K. pneumoniae isolates displayed a multidrug-resistant phenotype, exhibiting resistance or reduced susceptibility to ampicillin, ampicillin/sulbactam, cefazolin, aztreonam, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, nitrofurantoin, trimethoprim/sulfamethoxazole, apramycin, tigecycline and colistin. WGS analysis revealed that clinical strain TGC-02 carried the TmexCD1-toprJ1 gene on a 200-Kb IncFII/IncFIB-type plasmid, while mcr-8 was situated on a 146-Kb IncFII-type plasmid. In clinical strain TGC-05, TmexCD1-toprJ1 was found on a 300-Kb IncFIB/IncHI1B/IncR-type plasmid, and mcr-8 was identified on a 137-Kb IncFII/IncFIA-type plasmid. Conjugation experiments assessed the transferability of these plasmids. While transconjugants were not obtained for TGC-05 despite multiple screening with tigecycline or colistin, pTGC-02-tmex and pTGC-02-mcr8 from clinical K. pneumoniae TGC-02 demonstrated self-transferability through conjugation. Notably, the rearrangement of pTGC-02-tmex and pTGC-02-mcr8 via IS26 -based homologous recombination was observed. Moreover, the conjugative and fusion plasmids of the transconjugant co-harboured the tmexCD1-toprJ1 gene cluster and mcr-8.1 , potentially resulting from IS26 -based homologous recombination. Conclusion The emergence of colistin- and tigecycline-resistant K. pneumoniae strains is concerning, and effective surveillance measures should be implemented to prevent further dissemination.

Objective Infections caused by Carbapenem-resistant Enterobacterales (CRE) have high treatment costs, high mortality and few effective therapeutic agents. This study aimed to determine the risk factors for progression from intestinal colonization to infection in hematological patients and the risk factors for 30-day mortality in infected patients.Methods A retrospective case-control study was conducted in the Department of Hematology at Shandong Provincial Hospital affiliated to Shandong First Medical University from April 2018 to April 2022. Patients who developed subsequent infections were identified as the case group by electronic medical record query of patients with a positive rectal screen for CRE colonization, and patients who did not develop subsequent infections were identified as the control group by stratified random sampling. Univariate analysis and logistic regression analysis determined risk factors for developing CRE infection and risk factors for mortality in CRE-infected patients.Results Eleven hematological patients in the study developed subsequent infections. The overall 30-day mortality rate for the 44 hematological patients in the case-control study was 11.4% (5/44). Mortality was higher in the case group than in the control group (36.5 vs. 3.0%, P = 0.0026), and septic shock was an independent risk factor for death (P = 0.024). Univariate analysis showed that risk factors for developing infections were non-steroidal immunosuppressants, serum albumin levels, and days of hospitalization. In multivariable logistic regression analysis, immunosuppressants [odds ratio (OR), 19.132; 95% confidence interval (CI), 1.349-271.420; P = 0.029] and serum albumin levels (OR, 0.817; 95% CI, 0.668-0.999; P = 0.049) were independent risk factors for developing infections.Conclusion Our findings suggest that septic shock increases mortality in CRE-infected hematological patients. Hematological patients with CRE colonization using immunosuppressive agents and reduced serum albumin are more likely to progress to CRE infection. This study may help clinicians prevent the onset of infection early and take measures to reduce mortality rates.

The global health threat posed by carbapenem-resistant Klebsiella pneumoniae (CRKP) is exacerbated by the limited availability of effective treatments. Bacteriophages are promising alternatives to conventional antimicrobial agents. However, current phage databases are limited. Thus, identifying and characterizing new phages could provide biological options for the treatment of multi-drug resistant bacterial infections. Here, we report the characterization of a novel lytic phage, vB_KpnP_23, isolated from hospital sewage. This phage exhibited potent activity against carbapenemase-producing CRKP strains and was characterised by an icosahedral head, a retractable tail, and a genome comprising 40,987 base pairs, with a G + C content of 51 %. Capable of targeting and lysing nine different capsule types (K-types) of CRKP, including the clinically relevant ST11-K64, it demonstrated both high bacteriolytic efficiency and stability in various environmental contexts. Crucially, vB_KpnP_23 lacks virulence factors, antimicrobial resistance genes, or tRNA, aligning with the key criteria for therapeutic application. In vitro evaluation of phage-antibiotic combinations revealed a significant synergistic effect between vB_KpnP_23 and meropenem, levofloxacin, or amikacin. This synergy could lead to an 8-fold reduction in the minimum inhibitory concentration (MIC), suggesting that integrated treatments combining this phage with the aforementioned antibiotics may substantially enhance drug effectiveness. This approach not only extends the clinical utility of these antibiotics but also presents a strategic advance in combating antibiotic resistance. Specifically, it underscores the potential of phage-antibiotic combinations as a powerful tool in the treatment of infections caused by CRKP, offering a promising avenue to mitigate the public health challenges of antibiotic-resistant pathogens.

Providencia rettgeri has recently gained increased importance owing to the New Delhi metallo-beta-lactamase (NDM) and other beta-lactamases produced by its clinical isolates. These enzymes reduce the efficiency of antimicrobial therapy. Herein, we reported the findings of whole-genome sequence analysis and a comprehensive pan-genome analysis performed on a multidrug-resistant P. rettgeri 18004577 clinical strain recovered from the urine of a hospitalized patient in Shandong, China, in 2018. Providencia rettgeri 18004577 was found to have a genome assembly size of 4.6 Mb with a G + C content of 41%; a circular plasmid p18004577_NDM of 273.3 Kb, harboring an accessory multidrug-resistant region; and a circular, stable IncT plasmid p18004577_Rts of 146.2 Kb. Additionally, various resistance genes were identified in its genome, including bla(NDM-1), bla(OXA-10), bla(PER-4), aph(3 ')-VI, ant(2 '')-Ia, ant(3 ')-Ia, sul1, catB8, catA1, mph(E), and tet. Conjugation experiments and whole-genome sequencing revealed that the bla(NDM-1) gene could be transferred to the transconjugant via the formation of pJ18004577_NDM, a novel hybrid plasmid. Based on the genetic comparison, the main possible formation process for pJ18004577_NDM was the insertion of the [Delta ISKox2-IS26-Delta ISKox2]-aph(3 ')-VI-bla(NDM-1) translocatable unit module from p18004577_NDM into plasmid p18004577_Rts in the Russian doll insertion structure (Delta ISKox2-IS26-Delta ISKox2), which played a role similar to that of IS26 using the "copy-in" route in the mobilization of [aph(3 ')-VI]-bla(NDM-1). The array, multiplicity, and diversity of the resistance and virulence genes in this strain necessitate stringent infection control, antibiotic stewardship, and periodic resistance surveillance/monitoring policies to preempt further horizontal and vertical spread of the resistance genes. Roary analysis based on 30 P. rettgeri strains pan genome identified 415 core, 756 soft core, 5,744 shell, and 12,967 cloud genes, highlighting the "close" nature of P. rettgeri pan-genome. After a comprehensive pan-genome analysis, representative biological information was revealed that included phylogenetic distances, presence or absence of genes across the P. rettgeri bacteria clade, and functional distribution of proteins. Moreover, pan-genome analysis has been shown to be an effective approach to better understand P. rettgeri bacteria because it helps develop various tailored therapeutic strategies based on their biological similarities and differences.

ObjectivesUrinary tract infection (UTI) is one of the most common extraintestinal infections, and uropathogenic Escherichia coli (UPEC) is the main cause of UTIs. However, the ability to treat UTI has been compromised by the increase in antimicrobial resistance, especially carbapenem resistance. Here, we aimed to characterize the antimicrobial resistance and molecular epidemiology of carbapenem-resistant UPEC isolated in Shandong, China.MethodsIn total, 17 carbapenem-resistant UPEC (CR-UPEC) isolates were collected from July 2017 to May 2020 in the Shandong Provincial Hospital. Whole-genome sequencing and bioinformatics analyses were performed to understand the molecular epidemiology of CR-UPEC. Phylogenetic groups, drug resistance genes, biofilm formation, and virulence-related gene profiles of the isolates were analyzed. Plasmid profiling and conjugation assay were performed to evaluate the ability to transfer carbapenem resistance-related genes to other E. coli isolates. Biofilm formation was also evaluated, as it is important for the persistence of infectious diseases.ResultsWe observed that 15 out of 17 CR-UPEC strains were bla(NDM) producers, among which 4 isolates could transfer bla(NDM) to recipient cells. The predominant sequence type was ST167 (6/17), followed by ST410 (3/17). The most prevalent phylogenetic group was phylogenetic group A (10/17), followed by phylogenetic group C (3/17). One isolate was resistant to polymyxin, which was caused by the carriage of a transferable plasmid harboring mcr-1. Statistical analysis did not reveal any significant difference in the carriage rate of fimbriae-coding genes between strong and weak biofilm producers.ConclusionsOur observations may assist in developing new therapeutic methods for drug-resistant organisms.

Glioma is a brain tumor that arises in the central nervous system and is categorized according to histology and molecular genetic characteristics. Long non-coding RNAs (lncRNAs) are RNAs longer than 200 nucleotides in length. They have been reported to influence significant events such as carcinogenesis, progression, and increased treatment resistance on glioma cells. Long non-coding RNAs promote cell proliferation, migration, epithelial-to-mesenchymal transition and invasion in glioma cells. Various significant advancements in transcriptomic profiling studies have enabled the identification of immune-related long non-coding RNAs as immune cell-specific gene expression regulators that mediates both stimulatory and suppressive immune responses, implying lncRNAs as potential candidates for improving immunotherapy efficacy against tumors and due to the lack of different diagnostic and treatments for glioma, lncRNAs are potential candidates to be used as future diagnostic, prognostic biomarker and treatment tools for glioma. This review's primary purpose is to concentrate on the role of long non-coding RNAs in early glioma identification, treatment, and immunotherapy.

Tigecycline serves as one of the last-resort antibiotics to treat severe infections caused by carbapenem-resistant Enterobacterales. Recently, a novel plasmid-mediated resistance-nodulation-division (RND)-type efflux pump gene cluster, TmexCD1-ToprJ1, and its variants, TmexCD2-ToprJ2 and TmexCD3-ToprJ3, encoding tetracyclines and tigecycline resistance, were revealed. In this study, we reported three TmexCD2-ToprJ2-harboring Klebsiella species strains, collected from two teaching tertiary hospitals in China, including one K. quasipneumoniae, one K. variicola, and one K. michiganensis. The three strains were characterized by antimicrobial susceptibility testing (AST), conjugation assay, WGS, and bioinformatics analysis. AST showed that K. variicola and K. quasipneumoniae strains were resistant to tigecycline with MIC values of 4μg/ml, whereas the K. michiganensis was susceptible to tigecycline with an MIC value of 1μg/ml. The TmexCD2-ToprJ2 clusters were located on three similar IncHI1B plasmids, of which two co-harbored the metallo-β-lactamase gene blaNDM-1. Conjugation experiments showed that all three plasmids were capable of self-transfer via conjugation. Our results showed, for the first time, that this novel plasmid-mediated tigecycline resistance mechanism TmexCD2-ToprJ2 has spread into different Klebsiella species, and clinical susceptibility testing may fail to detect. The co-occurrence of blaNDM-1 and TmexCD2-ToprJ2 in the same plasmid is of particular public health concern as the convergence of “mosaic” plasmids can confer both tigecycline and carbapenem resistance. Its further spread into other clinical high-risk Klebsiella clones will likely exacerbate the antimicrobial resistance crisis. A close monitoring of the dissemination of TmexCD-ToprJ encoding resistance should be considered.

Treatment strategies of infection by carbapenem-resistant Klebsiella pneumoniae (CRKP) are limited. Fosfomycin, a broad-spectrum antibiotic, has attracted renewed interest in combination therapy to fight K. pneumoniae infections. However, reports on fosfomycin-resistant K. pneumoniae are increasing. Among the 57 CRKP strains, 40 (70.2%) were resistant to fosfomycin. Thus, whole-genome sequencing and bioinformatics analysis were conducted to reveal molecular characteristics of fosfomycin-resistant K. pneumoniae. Twenty-three isolates coharbored fosAkp and fosA3, with K. pneumoniae carbapenemase (KPC)-producing ST11-KL64-wzi64-O2 (n = 13) and ST11-KL47-wzi209-OL101 (n = 8), the predominating clonal groups, while fosA3 was not detected in isolates carrying class B carbapenemase genes. Twenty-two (out of 26) ST11-KL64 strains were positive for rmpA2, of which 12 carried fosA3. Four of the 23 fosA3-positive isolates could successfully transfer their fosfomycin-resistant determinants to Escherichia coli J53AziR. All four strains belonged to ST11-KL47 with the same pulsed-field gel electrophoresis profile, and their transconjugants acquired fosfomycin, carbapenem, and aminoglycoside resistance. A 127-kb conjugative pCT-KPC-like hybrid plasmid (pJNKPN52_KPC_fosA) coharboring fosA3, blaKPC–2, blaCTX–M–65, blaSHV–12, rmtB, and blaTEM–1 was identified. ST11-KL64 and ST11-KL47 K. pneumoniae, with higher resistance and virulence, should be critically monitored to prevent the future dissemination of resistance.

Background: The purpose of this study is to use whole genome sequencing (WGS) combined with epidemiological data to track a hospital infection of the carbapenem-resistant Klebsiella pneumoniae (CRKP), which affected 3 neonatal patients in the neonatal intensive care unit (NICU). Methods: The minimum inhibitory concentrations for the antimicrobial agents were determined according to the guidelines of the Clinical and Laboratory Standards Institute. Beta-lactamases were investigated using the polymerase chain reaction and DNA sequencing. The transferability of the plasmid was investigated by a conjugation experiment. The clonal relationships were evaluated using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). WGS and single nucleotide polymorphisms (SNPs) analysis were performed on the CRKP isolates to investigate how the infection might progress. Results: Nine CRKP isolates were obtained from the NICU, seven from three patients, one from a duster cloth and one from the hand of a nurse, they all harbored bla IMP-4. Other resistance genes including bla KPC-2, bla IMP-4, bla SHV-1, bla TEM-1, bla CTX-M-15, and bla DHA-1 were also detected. PFGE analysis showed that IMP-4-producing K. pneumoniae were clonally related, and MLST assigned them to a new sequence type 2253. The SNP variations throughout the genome divided the 9 strains into three clades. Clade 1 comprised 7 strains (K1- K2 and K4-K8), whereas clade 2 and 3 consisted of only one strain each: K3 and K9, respectively.The sputum isolate K3 from patient 3 was the most distinct one differing from the other eight isolates by 239-275 SNPs. Conclusions: This is a report of using WGS to track a hospital infecion of IMP-4-producing K. pneumoniae ST2253 among neonates. Nosocomial surveillance systems are needed to limit the spread of the infection caused by these pathogens resulting from the environmental exposure in NICUs.

Glioma is a common type of tumor originating in the brain. Glioma develops in the gluey supporting cells (glial cells) that surround and support nerve cells. Exosomes are extracellular vesicles that contain microRNAs, messenger RNA, and proteins. Exosomes are the most prominent mediators of intercellular communication, regulating, instructing, and re-educating their surrounding milieu targeting different organs. As exosomes' diameter is in the nano range, the ability to cross the blood-brain barrier, a crucial obstacle in developing therapeutics against brain diseases, including glioma, makes the exosomes a potential candidate for delivering therapeutic agents for targeting malignant glioma. This review communicates the current knowledge of exosomes' significant roles that make them crucial future therapeutic agents and diagnostic tools for glioma.

Background Accurate and rapid diagnosis of Clostridium difficile infection (CDI) is critical for effective patient management and implementation of infection control measures to prevent transmission. Objectives We updated our previous meta-analysis to provide a more reliable evidence base for the clinical diagnosis of Xpert C. difficile (Xpert C. difficile ) assay. Methods We searched PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and the Chinese Biomedical Literature Database (CBM) databases to identify studies according to predetermined criteria. STATA 13.0 software was used to analyze the tests for sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the summary receiver operating characteristic curves (AUC). QUADAS-2 was used to assess the quality of included studies with RevMan 5.2. Heterogeneity in accuracy measures was tested with Spearman correlation coefficient and chi -square. Meta-regressions and subgroup analyses were performed to figure out the potential sources of heterogeneity. Model diagnostics were used to evaluate the veracity of the data. Results A total of 26 studies were included in the meta-analysis. The pooled sensitivity (95% confidence intervals [CI]) for diagnosis was 0.97(0.95–0.98), and specificity was 0.96(0.95–0.97). The AUC was 0.99 (0.98–1.00). Model diagnostics confirmed the robustness of our meta-analysis’s results. Significant heterogeneity was still observed when we pooled most of the accuracy measures of selected studies. Meta-regression and subgroup analyses showed that the sample size and type, ethnicity, and disease prevalence might be the conspicuous sources of heterogeneity. Conclusions The up-to-date meta-analysis showed the Xpert CD assay had good accuracy for detecting CDI. However, the diagnosis of CDI must combine clinical presentation with diagnostic testing to better answer the question of whether the patient actually has CDI in the future, and inclusion of preanalytical parameters and clinical outcomes in study design would provide a more objective evidence base.

The reverse transcriptase inhibitors such as lamivudine (3TC) play important roles in anti-ageing, but their effects on neurodegenerative diseases caused by ageing are not clear, especially on the functions of the nervous system such as cognition. In this study, we administered 3TC to senescence-accelerated mouse prone 8 (SAMP8) mice by gastric perfusion (100 mg/kg) for 4 weeks. Our results showed that 3TC significantly improved the ageing status of SAMP8 mice, especially the decline of cognitive ability evaluated by the Morris water maze test. To further investigate the molecular mechanisms of improving the ageing status of SAMP8 mice by 3TC, the qPCR and tissue staining methods were used to study the brain tissues (i.e., hippocampus and cortex) of mice, while the network pharmacology analysis was applied to investigate the potential targets of 3TC. The results showed that the mRNA levels of genes related to long interspersed element-1, type 1 interferon response, the senescence-associated secretion phenotype and the Alzheimer's disease in the hippocampus and cortex of SAMP8 mice were increased due to senescence, but this trend was reversed partially by 3TC. Results of histological studies showed that 3TC reduced the death of hippocampal neurons, while the results of network pharmacology analysis indicated that 3TC may exert its influence through multiple pathways, including the oestrogen signalling and the PI3K/Akt and neuroactive ligand-receptor interaction signalling pathways, which we have verified through in vitro experiments. These findings provide evidence for the therapeutic potential of 3TC in the treatment of neurodegenerative diseases.

NDM-7, a variant of New Delhi metallo-beta-lactamases (NDM), has the highest carbapenem-hydrolyzing activity. NDM-7-producing enterobacteria have been reported in many countries. In this study, we reported NDM-7 production in ST11 Klebsiella pneumoniae isolated from a boy hospitalized in the pediatric intensive care unit of a teaching hospital in China. The isolate exhibited resistance to β-lactam antimicrobials, quinolones, and trimethoprim/sulfamethoxazole, and it harbored blaNDM–7, blaCTX–M–15, qnrA, qnrB, and qnrS. The serotype of the isolated K. pneumoniae was assigned as K1, and it contained three virulence genes, including kfuBC, uge, and fim. The blaNDM–7 gene was located on a conjugative IncX3 plasmid designated as pB14NDM-7. This plasmid was fully sequenced and compared with the available blaNDM–7-harboring IncX3 plasmids. pB14NDM-7 contained a conserved genetic context of ISkox3-umuD-IS26-ΔTn125-IS5-ΔTn125-IS3000-ΔTn2. pB14NDM-7 showed 99% nucleotide identity and the same genetic context with three blaNDM–7-harboring IncX3 plasmids obtained from Escherichia coli in China. Our results indicate that IncX3 plasmid may contribute to the prevalence of blaNDM–7 in China. The high prevalence of NDM variants worldwide highlights the critical need for careful monitoring and control of the rapid dissemination of blaNDM.

Application of matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI‐TOF MS) using positive blood cultures (BCs) is a revolution in identification of microorganisms in clinical microbiology laboratories. Although there are several commercial pretreat‐ ment protocols they are expensive. Here, we evaluated the performance of a locally produced Bioyong pre‐treatment kit for the direct identification of microorganisms in positive BCs by MALDI‐TOF MS method. The mocked positive BCs were performed using 200 Thermo aerobic blood culture bottles and 200 aerobic Scenker blood culture bottles. A total of 200 organisms were invovled, including 91 strains of Gram‐positive bacteria, 97 strains of Gram‐negative bacteria and 12 strains of Candida. The positive BCs were subcultured and identified by classical biochemical Vitek II testing as the gold standard of identification. The Bioyong pre‐treatment kit could successfully identify microorganisms in 189 (94.5%) Thermo positive BCs and 189 (94.5%) Scenker positive blood cultures, respectively. In total, 94 (96.9%) Gram‐negative bacteria, 86 (94.5%) Gram‐positive bacteria and 9 (75.0%) candida isolated from Thermo positive BCs were correctly identified to species level and 95 (97.9%) Gram‐negative bacteria, 86 (94.5%) Gram‐positive bacteria and 8 (66.7%) candida isolated from Scenker positive BCs were correctly identified to species level. This method provides a rapid, accu‐ rate identification of bacteria and Candida within one hour in positive blood cultures. Routine application of this technique will improve the antimicrobial treatment within 24 h among the patients with bacteremia and candidemia. Introduction Blood stream infections (BSIs) remain one of the most serious infections with high morbidity and mortality. Rapid identifica‐ tion of the causative microorganism and the correct initial anti‐infection treatment is especially critical for sepsis patients. The delay of appropriate anti‐infection treatment may increase the mortality of patients (1). Moreover, appropriate anti‐infection therapeutic option determines the survival rate of patients (2). Accurate and rapid diagnosis of etiological diagnosis is the key to reduce the time and cost of hospitalization (3). Blood culture is still the most important diagnostic method for BSIs. For positive blood cultures, the traditional laboratory process is performed based on Gram staining, subculture, biochemical identification and antimicrobial susceptibility tests. The laboratory reports commonly need 48‐72 h. If the pathogen grows harsh or inert, the cycle will be even longer. In recent years, a variety of new rapid identification methods such as real‐time quantitative PCR, multiple PCR, fluores‐ cence in situ hybridization (FISH) and peptide nucleic acid hybridization (PNAFISH) have been introduced into the field of microbial identification (4). However, these methods are limited to detecting the target microorganisms. In addition, the cost of reagents and instruments of these methods is high. In 2009, MALDI‐TOF MS was firstly introduced into the field of clinical microbiology identification directly from positive blood cultures (BCs) (5). At present, MALDI‐TOF MS is becoming more mature for pure colony identification with high accuracy and repeatability. In almost all studies, the identification accuracy of this method was better than the routinely used biochemical identification method, with the test cycle shortened and the required cost reduced (6). There are several in‐house methods for the identification of pathogens directly from BCs or other primary specimens developed. However, none is commonly used because there is no standardization. There are also several imported commer‐ cial kits in China, but the prices are relative high for routine operation in clinical laboratories. Bioyong kit is a recently developed pretreatment method to improve the performance of direct MALDI‐TOF MS identification from positive BCs. The Bioyong sample preparation kit was produced in China locally, aimed to cut down costs and increase sensitivity. The Rapid method for direct identification of positive blood cultures by MALDI‐TOF MS YUELING WANG1, YAN JIN1, YUANYUAN BAI1, ZHEN SONG1, WENJUN CHU1, MENGQI ZHAO1, YINGYING HAO1,2 and ZHIMING LU1,2 1Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University; 2Department of Clinical Laboratory, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250021, P.R. China Received February 18, 2020; Accepted August 27, 2020 DOI: 10.3892/etm.2020.9365 Correspondence to: Dr Zhiming Lu or Dr Yingying Hao, Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jing‐Wu, Jinan, Shandong 250021, P.R. China E‐mail: r8s272@163.com E‐mail: luzhiming@sdu.edu.cn; haoyyjia@163.com