Background: The emergence of polymyxin-resistant, carbapenem-resistant Klebsiella pneumoniae (CRKP) presents a critical challenge to clinical management. This study aimed to delineate the molecular mechanisms driving the acquisition of polymyxin resistance in CRKP. Methods: We analyzed polymyxin-susceptible and polymyxin-resistant CRKP isolates obtained from a single patient. Antimicrobial susceptibility testing was performed to determine the minimum inhibitory concentrations. Whole genome sequencing was employed to identify variations in two-component systems and to screen for mcr genes, which were involved in polymyxin resistance. Differential gene expression was assessed using RNA sequencing and validated by quantitative real-time PCR. Furthermore, site-directed mutagenesis was utilized to confirm the causal role of specific mutations in conferring the resistant phenotype. Results: An L96P mutation in the PhoQ protein was found in the polymyxin-resistant CRKP isolate. Compared with the PhoQ wild-type, this mutation significantly upregulated expression of phoP/Q, pmrD, and arnBCADTEF operon-related genes. A corresponding L96P mutant was subsequently constructed in the polymyxin-susceptible ATCC 13883 strain via site-directed mutagenesis. Antimicrobial susceptibility testing confirmed that the PhoQ L96P mutation elevates the minimal inhibitory concentrations of colistin and polymyxin B to 64 mg/L and >32 mg/L, respectively, from a baseline of 0.5 mg/L. Conclusions: The PhoQ L96P mutation is a pivotal driver of polymyxin resistance in CRKP, primarily mediated through the upregulation of the arnBCADTEF operon.

The plasmid-mediated tigecycline resistance gene tmexCD1-toprJ1 and its variants have emerged as a public health threat, with increasing identification in various sources of Enterobacterales worldwide. However, comprehensive epidemiological features of tmexCD1-toprJ1 in clinical carbapenem-resistant Klebsiella pneumoniae (CRKP) remain limited. Herein, we conducted a retrospective nationwide surveillance to assess the prevalence and molecular epidemiology of clinical tmexCD1-toprJ1-positive isolates from 4314 non-duplicated CRKP strains collected from 151 medical institutions across 31 provinces, municipalities, and autonomous regions in China. tmexCD1-toprJ1 was detected in 18 (0.42%) CRKP strains spanning 12 provinces, all exhibiting multidrug resistance phenotypes. ST147 was the dominant sequence type and predominantly co-harbored blaKPC-2. Phylogenetic analysis unveils the intrahospital, interhospital, and interprovincial spread of tmexCD1-toprJ1 carrying ST147 CRKP, which display a closer genomic proximity to those from other global regions, suggesting the international transmission risk of tmexCD1-toprJ1. Variable tigecycline resistance levels among isogenic ST147 strains were associated with differential tmexCD1-toprJ1 expression. Further, three types of plasmid replicons were found in the carriage of tmexCD1-toprJ1, among which IncFIB(K) and IncFIB(K)/IncHI1B were the primary vectors of tmexCD1-toprJ1, and a multireplicon megaplasmid was identified. The emergence of regionally disseminated tmexCD1-toprJ1-bearing ST147 CRKP clone highlights the potential global spread risk of tmexCD1-toprJ1, underscoring the urgent need for further surveillance and control measures to mitigate the ongoing spread of this resistant pathogen.

OBJECTIVES:Community-acquired and hospital-acquired bloodstream infections (CA-BSI and HA-BSI) caused by Gram-negative bacteria (GNB) pose major clinical risks, but differences in their molecular epidemiology and prognostic etiologic factors remain unclear. METHODS:A genomic epidemiology study analyzed 933 CA-BSI and 1001 HA-BSI isolates from 21 major Chinese teaching hospitals. We collected comprehensive clinical data and conducted molecular characterization, including sequence types, antibiotic resistance genes, virulence factors, and plasmid types, as well as clinical phenotypes of major pathogens. Multivariable Cox models were used to identify mortality predictors. RESULTS:Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacter cloacae complex were the predominant species in both CA-BSI and HA-BSI groups but exhibited distinct clinical and molecular characteristics between CA-BSI and HA-BSI. CA-BSI patients showed significantly higher inflammatory markers (CRP, PCT, WBC, and Neu%), while HA-BSI patients had significantly poorer prognosis including prolonged hospitalization, higher ICU admission rates and clinical deterioration or mortality. Genomic surveillance revealed a critical divergence: HA isolates were dominated by high-risk clones such as ST11 K. pneumoniae and ST2 A. baumannii, which were enriched in antimicrobial resistance genes, directly linking to worse outcomes. CA isolates, while more diverse, were characterized by specific lineages including ST131 E. coli (enriched with specific virulence genes: yersiniabactin, K1 capsule, and P fimbriae) and ST23 K. pneumoniae, which carried a significantly greater number of virulence genes. Multivariable analysis confirmed that mortality risk profiles are setting-specific, influenced by distinct combinations of patient comorbidities (including age, gender, agranulocytosis, and infection source) and bacterial genetic determinants (such as lacI or aadA2 for K. pneumoniae and aph(3')-Ia for A. baumannii). CONCLUSIONS:This first genomic epidemiological investigation of GNB-BSIs stratified by acquisition setting reveals a fundamental clinical and epidemiological divergence between CA- and HA-cases. The study underscores that tracking mortality-associated strains and genes is essential for improving clinical outcomes and advancing etiological knowledge.

INTRODUCTION:Sepsis remains one of the leading causes of death worldwide. Monocytes play a pivotal role in sepsis due to their dual role in both pro-inflammation and immunosuppression. However, the phenotypic markers and developmental characteristics of immunosuppressive monocytic myeloid-derived suppressor cells (M-MDSCs) in sepsis remain largely unknown. OBJECTIVES:This study aimed to investigate the functional heterogeneity of M-MDSCs in sepsis. METHODS:The frequency of M-MDSCs was assessed for the prognosis of sepsis. Single-cell RNA sequencing was conducted on purified HLA-DRhighCD14+ and HLA-DRlowCD14+ monocytes, respectively, from patients with sepsis to study their heterogeneity. RESULTS:We find that the frequency of M-MDSCs, as defined by classical markers, has limited value in the prognosis of sepsis due to their broad heterogeneity. Based on scRNA-seq analysis, M-MDSCs in sepsis are established as HLA-DRlowCD14+ monocytes, which display high expression of RETN and low expression of HLA-DPB1. We further segregate M-MDSCs into five subsets: IL1R2_M-MDSC, THBS1_M-MDSC, S100A_M-MDSC, IFN-sti_M-MDSC, and PPBP_M-MDSC, with the first three subsets accounting for the majority of the population. Pro-inflammatory S100A_M-MDSC dominates early-stage population and is characterized by high expression of S100A. Middle-stage IL1R2_M-MDSC exhibits cytokine production, while THBS1_M-MDSC is associated with TGF-β signaling, revealing concurrent pro-inflammatory and immunosuppressive functions. In the late stage, both THBS1_M-MDSC and IL1R2_M-MDSC display immunosuppressive functions. Furthermore, our data suggest a metabolic shift from oxidative phosphorylation to fatty acid and amino acid biosynthesis as pro-inflammatory monocytes transition into immunosuppressive M-MDSCs. VSIG4, a novel functional marker of immunosuppressive M-MDSCs, is specifically expressed in THBS1_M-MDSC. Subsequently, our preliminary results suggest that the combined detection of surface VSIG4 and IL1R2 on HLA-DRlowCD14+ monocytes shows potential for predicting sepsis outcomes. CONCLUSION:This study illuminates the characteristics of M-MDSCs in sepsis, providing a new direction for disease prognosis.

Background: Trichosporon japonicum is a rare but highly lethal pathogen causing fungemia in immunocompromised patients. With the expanding use of chimeric antigen receptor T (CAR-T) cell therapy, the spectrum of opportunistic fungal infections is changing, yet data on T. japonicum infections in this setting remain scarce. Case Presentation: A 69-year-old man with diffuse large B-cell lymphoma developed catheter-associated fungemia after CAR-T cell reinfusion. He initially presented with neck pain and white oral mucosal patches, followed by fever four days later. T. japonicum was isolated from both peripheral blood and central venous catheter tip cultures, identified by microscopic examination, mass spectrometry, and molecular sequencing. Antifungal prophylaxis was initiated before fever onset based on close monitoring of white blood cell count, procalcitonin, interleukin-6, and C-reactive protein; treatment was subsequently adjusted according to species identification and antifungal susceptibility results. Infection was controlled within two weeks after catheter removal and immune recovery. The patient remained well at six-month follow-up. Conclusion: This case adds to the limited literature on T. japonicum fungemia in patients receiving CAR-T therapy. Our experience, together with a review of the literature, underscores that successful management requires prompt catheter removal, immune restoration, and combination therapy with voriconazole and amphotericin B, as echinocandin monotherapy should be avoided. Awareness of this pathogen in immunocompromised patients is critical.

Gut microbiota may play a role in regulating the stress hormone cortisol. However, the mechanisms underlying the regulation of cortisol by gut microbiota are poorly understood. Here, it is found that gut microbiota degraded cortisol, and this ability is heterogeneous among individuals. Mice gavaged with gut microbiota having a low ability to degrade cortisol may be prone to developing depressive-like behavior. The cortisol-degrading strain Pseudomonas aeruginosa Tongji is isolated from faecal microbiota. The des-like enzyme expressed by P. aeruginosa Tongji converts cortisol into androgen. Bacterial des-like enzyme protects mice against depressive-like behavior via degrading cortisol and producing androgen. The probiotic Bacillus subtilis expressing the des-like enzyme is constructed, which protects the host against cortisol elevation. These findings suggest that bacterial des-like enzyme may regulate cortisol and improve depression by converting cortisol into androgen.

BACKGROUND:Peptoniphilus vaginalis, a Gram-positive anaerobic coccus, is a recently characterized species within the Peptoniphilus genus. No studies have detailed its features. This report documents the first case of P. vaginalis bloodstream infection in a patient with diabetic foot infection, with a review of existing literature. CASE PRESENTATION:A 55-year-old male presented with multiple skin ulcers on both lower extremities and hyperpyrexia. Blood cultures were conducted, and analysis via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) revealed two distinct colony morphologies, namely Peptoniphilus spp. and Staphylococcus epidermidis. Discrepancies between MALDI-TOF MS results and biochemical identification prompted 16S rRNA sequencing, which confirmed P. vaginalis. The patient underwent surgical debridement and received intravenous antibiotics (levofloxacin, linezolid, and ornidazole), resulting in favorable recovery. CONCLUSIONS:This is the first report of P. vaginalis bloodstream infection in a patient with diabetic foot infection. It was observed that conventional biochemical identification methods and MALDI-TOF MS technology may not reliably detect P. vaginalis. In the absence of more advanced molecular methods, P. vaginalis could potentially be misidentified as Peptoniphilus harei, even in the previously published literature. Catalase testing may serve as a pragmatic discriminator in resource-limited settings, which required further validation. This underscores the necessity for employing molecular biology techniques to ensure precise diagnosis and optimize treatment strategies.

Infections attributed to Helcococcus kunzii are rarely documented, especially in relation to brain abscesses. This study aims to report the first documented case of a brain abscess associated with tympanitis caused by H. kunzii in China, alongside a comprehensive review of the existing literature. We detail the case of a 54-year-old female patient with a history of hypertension, who was diagnosed with tympanitis complicated by a brain abscess. An urgent occipital lobectomy was performed, during which pus was collected for culture analysis. Three distinct colony morphologies were identified through matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analysis, including H. kunzii and two additional anaerobic bacterial species. Subsequent biochemical assays and 16S rRNA gene sequencing corroborated the presence of H. kunzii. Antimicrobial susceptibility testing revealed that the isolated H. kunzii strain exhibited resistance to erythromycin and clindamycin. The patient was subsequently treated with intravenous antibiotics, specifically ceftriaxone, meropenem, and norvancomycin, resulting in complete recovery. This case underscores the increasing acknowledgment of H. kunzii as a notable pathogen in invasive intracranial infections. It is imperative for clinicians to consider H. kunzii in the differential diagnosis of patients presenting with intracranial infections, especially those with a history of tympanitis, to ensure prompt and effective management. The utilization of MS and molecular techniques should be prioritized for the accurate identification of these anaerobic bacteria.

Objective:To establish the epidemiological cut-off values (ECOFFs) of sitafloxacin against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, and Streptococcus pneumoniae. Methods:We collected 2264 clinical isolates from five different labs located in four cities in China. The minimum inhibitory concentrations (MICs) and inhibition zone diameters of sitafloxacin for all isolates were determined by using the broth microdilution method (BMD) and the disk diffusion method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. MIC ECOFFs were determined using ECOFFinder software, with the 99% calculated ECOFF selected as the initial value. Zone diameter ECOFFs were determined via the visual estimation method. Whole-genome sequencing was performed on E. coli strains exhibiting overlapping MICs between wild-type (WT) and non-wild-type (NWT) groups to analyze resistance mechanisms. Results:Sitafloxacin MICs ranged from 0.002 to 64 mg/L, while inhibition zone diameters ranged from 6 to 45 mm across the nine species. MIC ECOFFs were determined as 0.032, 0.064, 0.125, 0.5, 0.064, 0.125, 0.5, 0.25, and 0.125 mg/L for E. coli, K. pneumoniae, P. mirabilis (tentative ECOFF), P. aeruginosa, A. baumannii, S. aureus, E. faecalis, E. faecium, and S. pneumoniae, respectively. Except for S. pneumoniae, MICs of the other eight species showed a high correlation with zone diameters (|r| > 0.8, P < 0.0001). Consequently, the zone diameter ECOFFs were established as 26, 25, 24, 24, 25, 26, 21, and 22 for E. coli, K. pneumoniae, P. mirabilis, P. aeruginosa, A. baumannii, S. aureus, E. faecalis, and E. faecium, respectively. Conclusion:We established MIC and zone diameter ECOFFs for sitafloxacin against the nine species listed above. The MIC ECOFF for P. mirabilis was classified as tentative. For S. pneumoniae, the correlation between zone diameters and MICs was insufficient to establish a zone diameter ECOFF.

Salmonella enterica subsp. enterica serovar Mbandaka (S. Mbandaka) represents an emerging public health threat due to its remarkable genomic adaptability, involvement in multinational foodborne outbreaks, and the ability to establish persistent infections. Here, we report the first documented isolation of a carbapenem-resistant S. Mbandaka strain, a significant public health concern given the critical role of carbapenems in treating multidrug-resistant infections. Five clonal S. Mbandaka isolates were obtained from a single patient, with three isolates (SM_F22R, SM_F28R, and SM_B30R) exhibiting carbapenem resistance mediated by the blaNDM-1. The comprehensive genomic analysis uncovered a 1,220 kb chromosomal inversion mediated by IS26 through intramolecular replicative transposition (in trans), generating the SM_F28R and SM_B30R variants. Using S1 pulsed-field gel electrophoresis, Southern blotting, and conjugation experiments, we demonstrated the transfer of blaNDM-1: chromosomal localization in SM_F22R and plasmid-borne (IncC-type) carriage in SM_F28R and SM_B30R. Notably, the region carrying blaNDM-1 in both locations was flanked by IS26 and completely identical, indicating that IS26 may facilitate the transfer of blaNDM-1 between the chromosome and plasmid. Additionally, we detected the amplification of mph(A) on the chromosome and blaNDM-1 on the IncC plasmid. The expression level of blaNDM-1 in SM_F22R was lower than that in SM_F28R and SM_B30R, consistent with SM_F22R exhibiting lower carbapenem resistance compared to SM_F28R and SM_B30R. This study reported the IS26-mediated transfer of blaNDM-1 between the chromosome and a plasmid in S. Mbandaka, highlighting the critical role of transposable elements in disseminating carbapenem resistance.IMPORTANCEAs a clinically significant foodborne pathogen, carbapenem-resistant Salmonella presents a significant therapeutic challenge due to its extensive antibiotic resistance. While blaNDM-1 is conventionally plasmid-borne, our study elucidates its transfer between chromosomes and a conjugative IncC plasmid in Salmonella. Our findings demonstrate the pivotal involvement of IS26 and ISCR1 mobile genetic elements in orchestrating genomic rearrangements while concurrently mediating the horizontal transfer and subsequent amplification of antimicrobial resistance determinants. This study provides an important theoretical basis for an in-depth analysis of the horizontal transfer mechanism of bacterial resistance genes.

BACKGROUND:The challenge of dealing with isolated reactive treponemal chemiluminescence immunoassay (CIA) results in clinical practice has prompted the development of a more efficient algorithm for distinguishing true infection from false reactivity in isolated CIA sera. METHODS:A prospective cohort study was conducted at Wuhan Tongji Hospital, involving 119,002 individuals screened for syphilis using CIA from January 1, 2015, to January 6, 2017. Samples with reactive CIA results underwent simultaneous testing with the T. pallidum passive particle agglutination assay (TPPA) and the rapid plasma reagin test (RPR). Additionally, a subgroup of 189 individuals with differing TPPA statuses was selected for further analysis using Western blotting (WB) and a modified TPPA assay (titer, 1:20). To identify the optimal serological approach for distinguishing true from false reactivity in sera with isolated reactive CIAs (CIA+TPPA-RPR-), two distinct algorithms were developed and evaluated. The first algorithm involved reflexively testing CIA+TPPA-RPR- sera with the modified TPPA, followed by WB if nonreactive. The second algorithm began with WB, followed by the modified TPPA if nonreactive or indeterminate. RESULTS:WB demonstrated lower sensitivity compared to TPPA, but it identified six syphilis cases among the 89 CIA+TPPA- samples. Both WB and modified TPPA exhibited a specificity of 100%. The two supplementary confirmatory algorithms detected 12 additional syphilis cases, with the first algorithm being more cost-effective and labor-saving. CONCLUSION:A combination of a modified TPPA (titer, 1:20) and WB can serve as a reliable algorithm for distinguishing true syphilis infection from false reactive signals in isolated reactive CIA sera. CLINICAL TRIAL NUMBER:Not applicable.

Background Screening of malignant hematological diseases is of great importance for their diagnosis and subsequent treatment. This study constructed an optimal screening model for malignant hematological diseases based on routine blood cell parameters. Methods The venous blood samples of 1751 patients collected from 10 tertiary hospitals in China were divided into a training set (1223 cases) and a validation set (528 cases). In addition to the clinical diagnostic information of the samples in the training set, 26 blood cell parameters including morphological parameters were selected using manual screening and filtering to construct eight machine learning models. These models were used to identify hematological malignancies among the validation set. Results Comparison of the discrimination, calibration and clinical detection performance of the eight machine learning models revealed that the artificial neural network (ANN) model performed the optimal in identifying malignant haematological diseases in the validation set (528 cases), with an area under the receiver operating characteristic curve (AUC), accuracy, sensitivity and specificity of 0.906, 0.857, 0.832 and 0.884, respectively. Conclusion The ANN model constructed can be used for screening of malignant hematological diseases, especially in primary hospitals that lack comprehensive diagnosis, and this ANN model will help patients to get diagnosis and treatment of malignant hematological diseases as early as possible.

INTRODUCTION:Early diagnosis of lung cancer is still a challenge by using current diagnostic methods. OBJECTIVES:The study aims to explore the utilization of host immune parameters, in combination with conventional laboratory tests, for the early prediction of lung cancer. METHODS:Immune profiles were assessed by flow cytometry in 221 patients, and machine learning algorithms, utilizing either combined or routine indicators alone, were applied to classify lung cancer stages. RESULTS:The study revealed significant alterations in immune profiles across different stages of lung cancer. Notably, we observed a progressive increase in the percentages of effector memory CD8+ T cells and polymorphonuclear-MDSCs from healthy controls to patients with benign lesion, early-stage cancer, and late-stage cancer. Conversely, the percentages of naive CD8+ T cells, DCs, and NKG2D+ NK cells exhibited a decreasing trend throughout this progression. Accordingly, the gradual differentiation of effector CD8+ T cells and the accumulation of inhibitory polymorphonuclear-MDSCs, along with the progressive impairment of innate and adaptive immunity, were the most prominent immune features observed during lung cancer progression. Through in combination of selected conventional laboratory and immune indicators, we demonstrated the effectiveness of machine learning models, particularly SVC and logistic regression, in predicting the presence of lung cancer and its staging with high accuracy. CONCLUSION:We depict the immune landscape in patients with benign disease and different stages of lung cancer. Combination of routine and immune indicators by using machine learning displays a potential in predicting the presence of lung cancer and its staging.

Background: Distinguishing between active tuberculosis disease (TBD) and latent tuberculosis infection (TBI) is crucial for TB control but remains challenging. Methods: Single-cell RNA sequencing was conducted on purified Mycobacterium tuberculosis (MTB)-specific CD154+CD4+ T cells. Results: We observe a superior role of CD154 in detecting MTB infection, whereas its ability in distinguishing TBD from TBI is still limited due to patient heterogeneity. Single-cell RNA sequencing of MTBspecific CD154+CD4+ T cells identifies 10 distinct clusters, including Treg, T_act, Th1_pex, Th1_eff, Tfh, T_na, Th17_ex, Th2, NKT, and Th1_cyt. Notably, effector and apoptotic Th1 cells are predominant in CD154+CD4+ T cells of TBD. However, Tfh cells are the primary component in TBI. Most Th1_pex cells are positioned at the end of the developmental trajectory and are regulated by key genes associated with apoptosis and early exhaustion, such as GADD45B, FOS, and EZH2. Oxidative stress-induced metabolic disorder, marked by increased metabolism of nitrogen, cysteine, and glutathione, also contributes to the apoptosis of Th1_pex cells. Using seven features including NA, CM, EM, EMRA, CXCR3+ Th1, IFN-gamma+ Th1, and Tfh of CD154+CD4+ T cells, both TBD and TBI can be classified into different subtypes, and a further established random forest model can accurately differentiate TBD from TBI. Additionally, the key checkpoints of exhausted MTBspecific Th1 cells are identified and blocking ADORA2A efficiently restores their function. Conclusions: We depict the cellular compositions, transcriptional characteristics, and developmental trajectories of MTB-specific CD154+CD4+ T cells from TBI to TBD, putting forward a new direction in the diagnosis and prognosis of disease. (c) 2025 The Author(s). Published by Elsevier Ltd on behalf of The British Infection Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Objectives: This study aimed to identify differences in risk factors for carbapenem-resistant Enterobacteriaceae (CRE) infections across different anatomical sites and to explore risk factors associated with mortality in CRE-infected patients. Methods: Patients who underwent CRE screening and were subsequently diagnosed with CRE infections were included and categorized by infection site: respiratory tract (RTI), urinary tract (UTI), and bloodstream (BSI). Forty ICU patients without CRE infection were randomly selected as controls. Statistical comparisons were performed using the Mann-Whitney U or Chi-square test, as appropriate. Potential risk factors were evaluated via univariate and multivariate analyses, and a predictive model was constructed, with its performance assessed using ROC curve analysis. Results: CRE colonization was identified as a common independent risk factor across all three groups (RTI, UTI, and BSI). Infection-site-specific analyses revealed independent risk factors: RTI was associated with mechanical ventilation, UTI with trauma, and BSI with gastrointestinal injury. Predictive models for RTI, UTI, and BSI demonstrated good discrimination, with ROC AUCs of 0.94, 0.94, and 0.95, respectively. In the analysis of Survived versus Deceased patients, the BSI group had the highest mortality, though the difference was not statistically significant. Deceased patients exhibited significantly higher PCT levels than Survived patients (p = 0.005). Prior use of carbapenems and antifungal agents, as well as Ln(PCT), were independently associated with mortality in CRE-infected patients. Conclusions: Risk factors for CRE infections vary across anatomical sites, with CRE colonization, mechanical ventilation, trauma, and gastrointestinal injury playing key roles. Overuse of antibiotics and elevated inflammatory responses are associated with increased mortality. These findings provide evidence for early identification of high-risk patients and optimization of individualized treatment strategies.

Epstein-Barr virus (EBV) is linked to a spectrum of diseases. To investigate the characteristics of various EBV-associated diseases in China, we conducted a multi-center retrospective cohort study examining molecular and serological features. EBV DNA copy numbers in plasma and peripheral blood mononuclear cells (PBMCs) were determined using quantitative polymerase chain reaction (qPCR), while four EBV-specific antibodies were assessed via chemiluminescence immunoassay. Our study included 746 patients with EBV-related diseases and 350 control adults without EBV-associated diseases. Among the patient group, EBV DNA was detectable in 97.7% of PBMC samples and 92.6% of plasma samples, significantly surpassing the positivity rates observed in controls (46.7% in PBMCs and 4.6% in plasma). In terms of specific diseases, EBV DNA was positive in PBMCs in almost all the patients across most disease groups, except in nasopharyngeal carcinoma (87.4%), whereas the EBV DNA positivity rates in plasma varied considerably. Most disease groups exhibited low positivity rates for viral capsid antigen (VCA)-IgM and high positivity rates for EBV nuclear antigen (EBNA)-IgG. Contrary, infectious mononucleosis demonstrated a high seropositivity rate (94.2%) for VCA-IgM but a low rate (0.8%) for EBNA-IgG. EBV DNA in plasma effectively distinguishes patients with EBV-associated diseases from control subjects, and incorporating PBMC EBV DNA further enhances diagnostic accuracy. In conclusion, our findings delineate distinct patterns of EBV DNA presence, levels, and antibody responses across various EBV-associated diseases. We recommend that plasma EBV DNA testing be employed as the first-line diagnostic approach for high-risk individuals, with subsequent PBMC EBV testing conducted for those exhibiting negative plasma results. A comprehensive evaluation of both EBV DNA and serological markers is essential for accurate identification and differential diagnosis of EBV-related disorders.

Objective To determine the epidemiological cut-off (ECOFF) values of etimicin against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus. Methods We selected 1500 isolates from five hospitals throughout five cities in China spanning from January 2018 to December 2021 in the study. Minimal inhibit concentrations (MICs) of etimicin were determined using the broth microdilution method. ECOFFs of etimicin against six species were calculated using ECOFFinder software and visual estimation following EUCAST principles. Results MICs of etimicin were distributed from 0.064 to >128 mg/L for S. aureus, from 0.125 to >128 mg/L for P. aeruginosa, from 0.25 to >128 mg/L for K. pneumoniae, P. mirabilis and A. baumannii, and from 0.5 to >128 mg/L for E. coli. The MIC ECOFF of etimicin was 2 mg/L for K. pneumoniae, 8 mg/L for E. coli and P. mirabilis, 16 mg/L for P. aeruginosa and A. baumannii, and the tentative ECOFF (TECOFF) of etimicin was 2 mg/L for S. aureus. Conclusions (T)ECOFFs of etimicin against E. coli, K. pneumoniae, P. mirabilis, P. aeruginosa, A. baumannii and S. aureus were determined, which will be helpful to differentiate wild-type strains.

Invasive diseases caused by the globally distributed commensal yeast Candida tropicalis are associated with mortality rates of greater than 50%. Notable increases of azole resistance have been observed in this species, particularly within Asia-Pacific regions. Here, we carried out a genetic population study on 1571 global C. tropicalis isolates using multilocus sequence typing (MLST). In addition, whole-genome sequencing (WGS) analysis was conducted on 629 of these strains, comprising 448 clinical invasive strains obtained in this study and 181 genomes sourced from public databases. We found that MLST clade 4 is the predominant azole-resistant clone. WGS analyses demonstrated that dramatically increasing rates of azole resistance are associated with a rapid expansion of cluster AZR, a sublineage of clade 4. Cluster AZR isolates exhibited a distinct high-level azole resistance, which was induced by tandem duplications of the ERG11 A395T gene allele. Ty3/gypsy -like retrotransposons were found to be highly enriched in this population. The alarming expansion of C. tropicalis cluster AZR population underscores the urgent need for strategies against growing threats of antifungal resistance.

INTRODUCTION:This study aims to assess the performance of the platelet count estimation using artificial intelligence technology on the MC-80 digital morphology analyzer. METHODS:Digital morphology analyzer uses two different computational principles for platelet count estimation: based on PLT/RBC ratio (PLT-M1) and estimate factor (PLT-M2). 977 samples with various platelet counts (low, median, and high) were collected. Out of these, 271 samples were immunoassayed using CD61 and CD41 antibodies. The platelet counts obtained from the hematology analyzer (PLT-I and PLT-O), digital morphology analyzer (PLT-M1 and PLT-M2), and flow cytometry (PLT-IRM) were compared. RESULTS:There was no significant deviation observed before and after verification for both PLT-M1 and PLT-M2 across the analysis range (average bias: -0.845/-0.682, 95% limit of agreement (LOA): -28.675-26.985/-29.420-28.056). When platelet alarms appeared, PLT-M1/PLT-M2 showed the strongest correlation with PLT-IRM than PLT-I with PLT-IRM (r: 0.9814/0.9796 > 0.9601). The correlation between PLT-M1/PLT-M2 and PLT-IRM was strong for samples with interference, such as large platelets or RBC fragments, but relatively weak in small RBCs. The deviation between PLT-M1 and PLT-M2 is related to the number of RBCs. Compared with PLT-I, PLT-M1/PLT-M2 showed higher accuracy for platelet transfusion decisions, especially for samples with low-value PLT. CONCLUSION:The novel platelet count estimation on the MC-80 digital morphology analyzer provides high accuracy, especially the reviewed result, which can effectively confirm suspicious platelet count.

Background: To investigate susceptibility to contezolid, a novel oxazolidinone, multicentre surveillance was conducted involving 2449 strains of Staphylococcus and Enterococcus collected from 65 hospitals across China. Methods: The MICs of contezolid, linezolid and other clinically significant antibiotics were determined by the broth microdilution method. Consistency with the broth microdilution method for contezolid was assessed using agar dilution method, as well as disc diffusion and ETEST for linezolid, respectively. WGS was conducted on all 20 linezolid-resistant and 30 randomly non-resistant strains to analyse linezolid resistance genes (optrA, poxtA, cfr) and 23S rRNA mutation sites. Results: All strains exhibited WT susceptibility to contezolid, while resistance proportions to daptomycin, vancomycin, teicoplanin, tigecycline and eravacycline ranged from 0% to 5.2% in Staphylococcus, and from 0% to 7.8% in Enterococcus. Linezolid resistance was higher in Enterococcus faecalis (4.4%) compared with Enterococcus faecium (0.2%). Contezolid showed a lower MIC50 (0.5 mg/L) than linezolid (2 mg/L) for methicillin-resistant Staphylococcus. Against Enterococcus, contezolid demonstrated a cumulative MIC percentage of 70% for VRE and 39.1% for E. faecalis (at MIC = 1 mg/L), whereas linezolid showed 0% and 1.1%, respectively. Among the 20 linezolid-resistant Enterococcus strains, all carried the optrA gene without 23S rRNA mutations. For contezolid, MICs were 4 mg/L for 19 strains and 2 mg/L for 1 strain. The ETEST, agar dilution and disc diffusion methods showed essential and categorical agreements of >90% for linezolid, with no major errors or very major errors. Conclusions: Contezolid demonstrated significant in vitro antibacterial activity against methicillin-resistant Staphylococcus, VRE and linezolid-resistant E. faecalis.