Mutations in the promoter region of methionine transporter gene metM (Rv3253c) confer para-aminosalicylic acid (PAS) resistance in Mycobacterium tuberculosis.

Tuberculosis (TB) is a significant global public health threat. Despite the long-standing use of para-aminosalicylic acid (PAS) as a second-line anti-TB drug, its resistance mechanism remains unclear. In this study, we isolated 90 mutants of PAS-resistant Mycobacterium tuberculosis (MTB) H37Ra in 7H11 solid medium and performed whole-genome sequencing, gene overexpression, transcription level comparison and amino acid level determination in MTB, and promoter activity by ß-galactosidase assays in Mycobacterium smegmatis to elucidate the mechanism of PAS resistance. Herein, we found that 47 of 90 (52.2%) PAS-resistant mutants had nine different mutations in the intergenic region of metM (Rv3253c) and Rv3254. Beta-galactosidase assays confirmed that mutations increased promoter activity only for metM but not Rv3254. Interestingly, overexpression of MetM or its M. smegmatis homolog (MSMEI_1796) either by its promoter in metM's direction or by exogenous expression in MTB induced PAS resistance in a methionine-dependent manner. Therefore, drug susceptibility results for the metM promoter mutants can be misleading when using standard 7H10 or 7H9 medium, which lacks methionine. At the metabolism level, PAS treatment led to higher intracellular methionine levels in the mutants than the wild type, antagonizing PAS and conferring resistance. Furthermore, 12 different mutations in the metM promoter were identified in clinical MTB strains. In summary, we found a novel mechanism of PAS resistance in MTB. Mutations in the metM (Rv3253c) promoter upregulate metM transcription and elevate intracellular methionine, which antagonize PAS. Our findings shed new light on the mechanism of PAS resistance in MTB and highlight issues with the current PAS susceptibility culture medium.IMPORTANCEAlthough para-aminosalicylic acid (PAS) has been used to treat TB for more than 70 years, the understanding of PAS resistance mechanisms is still vague, living gaps in our ability to predict resistance and apply PAS effectively in clinical practice. This study aimed to address this knowledge gap by inducing in vitro PAS resistance in Mycobacterium tuberculosis (MTB) using 7H11 medium and discovering a new PAS resistance mechanism. Our research revealed that spontaneous mutations occurring in the promoter region of the methionine transporting gene, metM, can upregulate the expression of metM, resulting in increased intracellular transport of methionine and consequently high-level resistance of Mycobacterium tuberculosis to PAS. Notably, this resistance phenotype cannot be observed when using the commonly recommended 7H10 medium, possibly due to the lack of additional methionine supply compared with that when using the 7H11 medium. Mutations on the regulatory region of metM were also found in some clinical MTB strains. These findings may have important implications for the unexplained PAS resistance observed in clinical settings and provide insight into the failures of PAS treatment. Additionally, they underscore the importance of considering the choice of culture media when conducting drug susceptibility testing for MTB.

The Emerging Role of Deubiquitinases in Radiosensitivity.

Radiation therapy is a primary treatment for cancer, but radioresistance remains a significant challenge in improving efficacy and reducing toxicity. Accumulating evidence suggests that deubiquitinases (DUBs) play a crucial role in regulating cell sensitivity to ionizing radiation. Traditional small-molecule DUB inhibitors have demonstrated radiosensitization effects, and novel deubiquitinase-targeting chimeras (DUBTACs) provide a promising strategy for radiosensitizer development by harnessing the ubiquitin-proteasome system. This review highlights the mechanisms by which DUBs regulate radiosensitivity, including DNA damage repair, the cell cycle, cell death, and hypoxia. Progress on DUB inhibitors and DUBTACs is summarized, and their potential radiosensitization effects are discussed. Developing drugs targeting DUBs appears to be a promising alternative approach to overcoming radioresistance, warranting further research into their mechanisms.

Vaccination Shapes Within-Host SARS-CoV-2 Diversity of Omicron BA.2.2 Breakthrough Infection.

BACKGROUND: Low-frequency intrahost single-nucleotide variants of SARS-CoV-2 have been recognized as predictive indicators of selection. However, the impact of vaccination on the intrahost evolution of SARS-CoV-2 remains uncertain at present. METHODS: We investigated the genetic variation of SARS-CoV-2 in individuals who were unvaccinated, partially vaccinated, or fully vaccinated during Shanghai's Omicron BA.2.2 wave. We substantiated the connection between particular amino acid substitutions and immune-mediated selection through a pseudovirus neutralization assay or by cross-verification with the human leukocyte antigen-associated T-cell epitopes. RESULTS: In contrast to those with immunologic naivety or partial vaccination, participants who were fully vaccinated had intrahost variant spectra characterized by reduced diversity. Nevertheless, the distribution of mutations in the fully vaccinated group was enriched in the spike protein. The distribution of intrahost single-nucleotide variants in individuals who were immunocompetent did not demonstrate notable signs of positive selection, in contrast to the observed adaptation in 2 participants who were immunocompromised who had an extended period of viral shedding. CONCLUSIONS: In SARS-CoV-2 infections, vaccine-induced immunity was associated with decreased diversity of within-host variant spectra, with milder inflammatory pathophysiology. The enrichment of mutations in the spike protein gene indicates selection pressure exerted by vaccination on the evolution of SARS-CoV-2.

Contrast-enhanced ultrasonography for identifying acute kidney injury in brain-dead donors.

Background: Acute kidney injury (AKI) is frequently found in deceased donors; however, few studies have reported the use of imaging to detect and identify this phenomenon. The purpose of this study was to detect renal microcirculatory perfusion in brain-dead donors using contrast-enhanced ultrasonography (CEUS), investigate the value of CEUS in identifying AKI, and analyze the correlation between CEUS and preimplantation biopsy results and early post-transplant renal function of grafts. Methods: This prospective study recruited 94 kidneys from brain-dead donors (AKI =44, non-AKI =50) from August 2020 to November 2022. The inclusion criteria were age ≥18 years and brain death. The exclusion criteria encompassed donors maintained with extracorporeal membrane oxygenation (ECMO) and the presence of irregular kidney anatomy. The mean age of the donors was 45.1±10.4 [standard deviation (SD)] years, and the majority were male (86.2%). CEUS was performed prior to organ procurement, and time-intensity curves (TICs) were constructed. The time to peak (TTP) and peak intensity (PI) of kidney segmental artery (KA), kidney cortex (KC), and kidney medulla (KM) were calculated using TIC analysis. Results: Arrival time (AT) of KA (P<0.001) and TTP of kidney cortex (TTPKC) (P<0.001) of the non-AKI group were significantly shorter than those of the AKI group. The PI of the KA (P=0.003), KM (P=0.005), and kidney cortex (PIKC; P<0.001) of the non-AKI group were significantly higher than those of the AKI group. Multivariable logistic regression analysis showed that serum creatinine [odds ratio (OR) =1.06; 95% CI: 1.03-1.1; P<0.001], TTPKC (OR =1.38; 95% CI: 1.03-1.84; P=0.03), and PIKC (OR =0.95; 95% CI: 0.91-1; P=0.046) were the independent factors of AKI. The area under the receiver operating characteristic curve (AUC) for identifying AKI for TTPKC and PIKC was 0.73 and 0.71, respectively. TTPKC showed a weak correlation with interstitial fibrosis (r=0.23; P=0.03), PIKC showed a weak correlation with arterial intimal fibrosis ((r=-0.29; P=0.004) and arteriolar hyalinosis (r=-0.27; P=0.008), and PIKC showed the strongest correlation with eGFR on postoperative day 7 (r=-0.46; P=0.046) in the donor kidneys with AKI. Conclusions: CEUS can be used to identify AKI in brain-dead donors. Furthermore, there is a correlation between CEUS-derived parameters and pretransplant biopsy results and early preimplantation renal function of grafts.

Contrast-enhanced ultrasonography-based renal blood perfusion in brain-dead donors predicts early graft function.

PURPOSE: The aim of this study was to quantify renal microcirculatory perfusion in braindead donors using contrast-enhanced ultrasonography (CEUS), and to establish an accurate, noninvasive, and convenient index for predicting delayed graft function (DGF) post-transplantation. METHODS: In total, 90 brain-dead donor kidneys (training group, n=60; validation group, n=30) examined between August 2020 and November 2022 were recruited in this prospective study. CEUS was performed on the kidneys of brain-dead donors 24 hours before organ procurement and time-intensity curves were constructed. The main measures were arrival time, time to peak, and peak intensity of the kidney segmental arteries, cortex, and medulla. Recipients were divided into DGF and non-DGF groups according to early post-transplant graft function. The area under the receiver operating characteristic curve (AUC) was used to assess diagnostic performance. RESULTS: The arrival time of the kidney segmental artery and cortex and the time interval between the time to peak of the segmental artery and cortex were identified as independent factors associated with DGF by multivariate stepwise regression analysis. A new index for the joint prediction model of three variables, the contrast-enhanced ultrasonography/Kidney Donor Profile index (CEUS-KDPI), was developed. CEUS-KDPI showed high accuracy for predicting DGF (training group: AUC, 0.91; sensitivity, 90.5%; specificity, 92.3%; validation group: AUC, 0.84; sensitivity, 75.0%; specificity, 92.3%). CONCLUSION: CEUS-KDPI accurately predicted DGF after kidney transplantation. CEUS may be a potential noninvasive tool for bedside examinations before organ procurement and may be used to predict early renal function after kidney transplants kidneys from donors after brain death.

The prognostic value of 11th Japanese classification and 8th AJCC staging systems in Chinese patients with esophageal squamous cell carcinoma.

BACKGROUND: Two staging systems, the 8th staging system by the American Joint Committee on Cancer (AJCC) and the 11th Japanese classification by Japan Esophageal Society (JES), are currently applied in the clinic for predicting the prognosis of patients with esophageal squamous cell carcinoma (ESCC). The differences between the two staging systems have been widely researched. However, little studies focus on the differences in specific staging between the two systems. Therefore, we aimed to compare the performance of different staging in predicting overall survival (OS) of Chinese patients with ESCC. METHODS: This retrospective study included 268 patients who underwent radical esophagectomy and mediastinal lymph node dissection for ESCC between January 2008 and December 2013. Patients were staged by the 8th AJCC and 11th JES staging systems. OS was estimated using the Kaplan-Meier method and compared between N stages and between stage groupings using the log-rank test. Cox proportional hazards regression analysis was performed to identify factors independently related to outcome. Further, we compared the concordance indexes (C-indexes) of the two staging systems. RESULTS: The mean age was 61.25 ± 7.056 years, median follow-up was 44.82 months, and 5-year OS rate was 47%. The OS was well predicted by the 8th AJCC N staging (P < 0.001) and the 11th JES N staging (P < 0.001), with a c-index of 0.638 (95% CI: 0.592-0.683) for AJCC N staging and 0.627 (95% CI: 0.583-0.670) for JES N staging (P = 0.13). In addition, the OS was also well predicted by stage groupings of the 8th AJCC (P < 0.001) and the 11th JES systems (P < 0.001), with a c-index of 0.658 (95% CI: 0.616-0.699) for 8th AJCC stage grouping and 0.629 (95% CI: 0.589-0.668) for the11th JES stage grouping (P = 0.211). CONCLUSIONS: The prognostic effect of 11th JES staging system is comparable with that of AJCC 8th staging system for patients with ESCC. Therefore, both systems are applicable to clinical practice.

Rapid Detection of Extensive Drug Resistance by Xpert MTB/XDR Optimizes Therapeutic Decision-Making in Rifampin-Resistant Tuberculosis Patients.

The Xpert MTB/XDR assay met the critical need for etiologic diagnosis of tuberculosis and rifampin resistance in previous studies. However, its benefits in tailoring the treatment regimen and improving the outcome for patients with rifampin-resistant tuberculosis (RR-TB) require further investigation. In this study, the Xpert MTB/XDR assay was used to determine the resistance profile of second-line drugs for RR-TB patients in two registered multicenter clinical trials, TB-TRUST (NCT03867136) and TB-TRUST-plus (NCT04717908), with the aim of testing the efficacy of all-oral shorter regimens in RR-TB patients in China. Patients would receive the fluoroquinolone-based all-oral shorter regimen, the injectable-containing regimen, or the bedaquiline-based regimen depending on fluoroquinolone susceptibility by using Xpert MTB/XDR. Among the 497 patients performed with Xpert MTB/XDR, 128 (25.8%) had infections resistant to fluoroquinolones and/or second-line injectable drugs (SLIDs). A total of 371 participants were recruited for the trials, and whole-genome sequencing (WGS) was performed on all corresponding culture-positive baseline strains. Taking the WGS results as the standard, the accuracy of the Xpert MTB/XDR assay in terms of resistance detection was 95.2% to 99.0% for all drugs. A total of 33 cases had inconsistent results, 9 of which were due to resistance heterogeneity. Most of the patients (241/281, 85.8%) had sputum culture conversion at 2 months. In conclusion, the Xpert MTB/XDR assay has the potential to serve as a quick reflex test in patients with RR-TB, as detected via Xpert MTB/RIF, to provide a reliable drug susceptibility profile of the infecting Mycobacterium tuberculosis strain and to initiate optimized treatment promptly.

Whole-Genome Sequencing and Comparative Genomics Analysis of a Newly Emerged Multidrug-Resistant Klebsiella pneumoniae Isolate of ST967.

Klebsiella pneumoniae is a common cause of hospital- and community-acquired infections globally, yet its population structure remains unknown for many regions, particularly in low- and middle-income countries (LMICs). Here, we report for the first-time whole-genome sequencing (WGS) of a multidrug-resistant K. pneumoniae isolate, ARM01, recovered from a patient in Armenia. Antibiotic susceptibility testing revealed that ARM01 was resistant to ampicillin, amoxicillin-clavulanic acid, ceftazidime, cefepime, norfloxacin, levofloxacin, and chloramphenicol. Genome sequencing analysis revealed that ARM01 belonged to sequence type 967 (ST967), capsule type K18, and antigen type O1. ARM01 carried 13 antimicrobial resistance (AMR) genes, including blaSHV-27, dfrA12, tet(A), sul1, sul2, catII.2, mphA, qnrS1, aadA2, aph3-Ia, strA, and strB and the extended-spectrum ß-lactamase (ESBL) gene blaCTX-M-15, but only one known virulence factor gene, yagZ/ecpA, and one plasmid replicon, IncFIB(K)(pCAV1099-114), were detected. The plasmid profile, AMR genes, virulence factors, accessory gene profile, and evolutionary analyses of ARM01 showed high similarity to isolates recovered from Qatar (SRR11267909 and SRR11267906). The date of the most recent common ancestor (MRCA) of ARM01 was estimated to be around 2017 (95% confidence interval [CI], 2017 to 2018). Although in this study, we report the comparative genomics analysis of only one isolate, it emphasizes the importance of genomic surveillance for emerging pathogens, urging the need for implementation of more effective infection prevention and control practices. IMPORTANCE Whole-genome sequencing and population genetics analysis of K. pneumoniae are scarce from LMICs, and none has been reported for Armenia. Multilevel comparative analysis revealed that ARM01 (an isolate belonging to a newly emerged K. pneumoniae ST967 lineage) was genetically similar to two isolates recovered from Qatar. ARM01 was resistant to a wide range of antibiotics, reflecting the unregulated usage of antibiotics (in most LMICs, antibiotic use is typically unregulated.) Understanding the genetic makeup of these newly emerging lineages will aid in optimizing antibiotic use for patient treatment and contribute to the worldwide efforts of pathogen and AMR surveillance and implementation of more effective infection prevention and control strategies.

Mo2 N-ZrO2 Heterostructure Engineering in Freestanding Carbon Nanofibers for Upgrading Cycling Stability and Energy Efficiency of Li-CO2 Batteries.

Li-CO2 batteries have attracted considerable attention for their advantages of CO2 fixation and high energy density. However, the sluggish dynamics of CO2 reduction/evolution reactions restrict the practical application of Li-CO2 batteries. Herein, a dual-functional Mo2 N-ZrO2 heterostructure engineering in conductive freestanding carbon nanofibers (Mo2 N-ZrO2 @NCNF) is reported. The integration of Mo2 N-ZrO2 heterostructure in porous carbons provides the opportunity to simultaneously accelerate electron transport, boost CO2 conversion, and stabilize intermediate discharge product Li2 C2 O4 . Benefiting from the synchronous advantages, the Mo2 N-ZrO2 @NCNF catalyst endows the Li-CO2 batteries with excellent cycle stability, good rate capability, and high energy efficiency even under high current densities. The designed cathodes exhibit an ultrahigh energy efficiency of 89.8% and a low charging voltage below 3.3 V with a potential gap of 0.32 V. Remarkably, stable operation over 400 cycles can be achieved even at high current densities of 50 µA cm-2 . This work provides valuable guidance for developing multifunctional heterostructured catalysts to upgrade longevity and energy efficiency of Li-CO2 batteries.

Totally-green cellulosic fiber with prominent sustained antibacterial and antiviral properties for potential use in spunlaced non-woven fabric production.

The worldwide spread of COVID-19 has put a higher requirement for personal medical protective clothing, developing protective clothing with sustained antibacterial and antiviral performance is the priority for safe and sustaining application. For this purpose, we develop a novel cellulose based material with sustained antibacterial and antiviral properties. In the proposed method, the chitosan oligosaccharide (COS) was subjected to a guanylation reaction with dicyandiamide in the presence of Scandium (III) triflate; because of the relatively lower molecular weight and water solubility of the COS, GCOS (guanylated chitosan oligosaccharide) with high substitution degree (DS) could be successfully synthetized without acid application. In this instance, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the GCOS were only 1/8 and 1/4 of that of COS. The introduction of GCOS onto the fiber endowed the fiber with extremely high antibacterial and antiviral performance, showing 100% bacteriostatic rate against Staphylococcus aureus and Escherichia coli and 99.48% virus load reduction of bacteriophage MS2. More importantly, the GCOS modified cellulosic fibers (GCOS-CFs) exhibit excellent sustained antibacterial and antiviral properties; namely, 30 washing cycles had negligible effect on the bacteriostatic rate (100%) and inhibition rate of bacteriophage MS2 (99.0%). Moreover, the paper prepared from the GCOS-CFs still exhibited prominent antibacterial and antiviral activity; inferring that the sheeting forming, press, and drying process have almost no effect on the antibacterial and antiviral performances. The insensitive of antibacterial and antiviral activity to water washing (spunlace) and heat (drying) make the GCOS-CFs a potential material applicable in the spunlaced non-woven fabric production.

Antibacterial and antiviral chitosan oligosaccharide modified cellulosic fibers with durability against washing and long-acting activity.

The worldwide outbreak of SARS-CoV-2 has attracted extensive attention to antibacterial and antivirus materials. Cellulose is the most potential candidate for the preparation of green, environmentally friendly antibacterial and antiviral materials. Herein, modified cellulosic fibers with sustained antibacterial and antiviral performance was prepared by introducing chitosan oligosaccharide onto the fibers. The two-step method is proved to be more effective than the one-step method for enhanced chitosan oligosaccharide loadings and antibacterial and antiviral activity. In this instance, the modified fibers with 61.77 mg/g chitosan oligosaccharide loadings can inhibit Staphylococcus aureus and Escherichia coli by 100 % after contacting with bacteria for 12 h and reduce the bacteriophage MS2 by 99.19 % after 1 h of contact. More importantly, the modified fibers have washing durable antibacterial and antiviral activity; the modified fibers have 100 % antibacterial and 98.38 % antiviral activity after 20 washing cycles. Benefiting from the excellent performance of the individual fibers, the paper prepared from the modified fibers show great antibacterial (100 %) and antiviral performance (99.01 %) and comparable mechanical strength. The modified fibers have potential applications in the manufacture of protective clothing and protective hygiene products.

Investigating a pulmonary Mycobacterium abscessus infection outbreak among elderly inpatients in the intensive care ward.

INTRODUCTION: Mycobacterium abscessus is an opportunistic nontuberculous mycobacteria pathogen; however, the prevalence of nosocomial and community infections is increasing. In January 2016, several bedridden inpatients in the intensive care unit of a hospital had positive sputum smears for acid-fast bacilli, suggesting a mycobacteria outbreak. METHODOLOGY: Acid-fast bacilli smear microscopy, isolation, and culturing were performed twice using sputa from each suspected intensive care unit inpatient (n = 13); in addition, medical history was obtained for each inpatient with suspected infection. Furthermore, environmental specimens were surveyed, collected, and cultured. We used DNA microarray chip analysis to identify positive mycobacterial isolates at the species level and performed whole-genome sequencing and phylogenetic tree construction. RESULTS: Seven inpatients had M. abscessus pulmonary infection, confirmed by 2 positive cultures; five of the inpatients had only one positive culture, while one had two negative cultures. Six of 13 ventilator condensate samples were mycobacterial culture-positive, identified as M. abscessus; the other environmental samples were negative. The M. abscessus isolates (15 sputa and 4 environmental samples) clustered together in the phylogenic analysis with only one single-nucleotide polymorphism difference. All patients were symptom-free after 8 months of multi-drug treatment. CONCLUSIONS: We confirmed a pulmonary M. abscessus outbreak among 12 bedridden patients in the intensive care unit through microbiological, molecular epidemiological, and environmental investigations. The possible infection source was contaminated ventilator condensate. This outbreak reemphasizes the importance of standardized ventilator maintenance and disinfection for preventing ventilator-associated pneumonia and is a reminder that nontuberculous mycobacteria-related ventilator-associated pneumonia is possible.

In vitro Susceptibility of Nontuberculous Mycobacteria to Tedizolid.

Objective: Nontuberculous mycobacteria (NTM) can cause pulmonary and extrapulmonary diseases. Tedizolid (TZD) is a new oxazolidinone with in vitro activity against NTM such as Mycobacterium avium complex (MAC), Mycobacterium fortuitum, and Mycobacterium abscessus complex. The aim of this study was to evaluate the TZD susceptibility profiles of clinical isolates of NTM. Methods: The microdilution method was used to identify the minimum inhibitory concentration (MIC) of TZD and linezolid (LZD) for 133 clinical NTM isolates. Broth microdilution chequerboard assays were used to investigate the synergistic effects of TZD and three antibiotics on two reference isolates and eleven clinical isolates of NTM. Results: The TZD MIC50 and MIC90 for M. abscessus complex were 2 and 4 µg/mL, 16 and >32 µg/mL for MAC, respectively. TZD exhibited lower MICs than that of LZD for most NTM, which were positively correlated. Due to the high MIC values of TZD against MAC, it is necessary to conduct drug sensitivity tests before TZD administration. TZD-clarithromycin combination had synergistic response on M. abscessus complex in 3 of the 8 isolates, which lasted only 3-5 days. TZD-cefoxitin had synergistic effect against all five M. fortuitum isolates. Conclusion: Our study demonstrates that TZD had greater in vitro potency than LZD, and synergy studies suggested that TZD may be an important component of multi-drug treatment regimen.

In vitro assessment of 17 antimicrobial agents against clinical Mycobacterium avium complex isolates.

BACKGROUND: Recently, Mycobacterium avium complex (MAC) infections have been increasing, especially in immunocompromised and older adults. The rapid increase has triggered a global health concern due to limited therapeutic strategies and adverse effects caused by long-term medication. To provide more evidence for the treatment of MAC, we studied the in vitro inhibitory activities of 17 antimicrobial agents against clinical MAC isolates. RESULTS: A total of 111 clinical MAC isolates were enrolled in the study and they were identified as M. intracellulare, M. avium, M. marseillense, M. colombiense, M. yongonense, and two isolates could not be identified at the species level. MAC strains had relatively low (0-21.6%) resistance to clarithromycin, amikacin, bedaquiline, rifabutin, streptomycin, and clofazimine, and the resistant rates to isoniazid, rifampin, linezolid, doxycycline, and ethionamide were very high (72.1-100%). In addition, M. avium had a significantly higher resistance rate than that of M. intracellulare for ethambutol (92.3% vs 40.7%, P < 0.001), amikacin (15.4% vs 1.2%, P = 0.049), and cycloserine (69.2% vs 25.9%, P = 0.004). CONCLUSIONS: Our results supported the current usage of macrolides, rifabutin, and aminoglycosides in the regimens for MAC infection, and also demonstrated the low resistance rate against new drugs, such as clofazimine, tedizolid, and bedaquiline, suggesting the possible implementation of these drugs in MAC treatment.

Guiding Value of Circulating Tumor Cells for Preoperative Transcatheter Arterial Embolization in Solitary Large Hepatocellular Carcinoma: A Single-Center Retrospective Clinical Study.

Background: Large hepatocellular carcinoma (LHCC) is highly malignant and prone to recurrence, leading to a poor long-term prognosis for patients. There is an urgent need for measures to intervene in postoperative recurrence. Preoperative Transcatheter Arterial Embolization (TACE) is an effective treatment. However, there is a lack of reliable preoperative indicators to guide the application of preoperative TACE. We, therefore, investigated whether the preoperative status of circulating tumor cells (CTCs) could be used to guide preoperative TACE for HCC treatment. Methods: This study recruited 361 HCC patients and compared recurrence-free survival (RFS) and overall survival (OS) in patients treated with TACE prior to surgery and those not treated with TACE. Patients were divided into CTC-positive group and CTC-negative group according to CTC status, and the effect of preoperative TACE on RFS and OS was compared in each subgroup. Results: In CTC-positive patients, preoperative TACE reduces early recurrence and improves long-term survival. However, HCC patients did not benefit from preoperative TACE for the overall population and CTC-negative patients. Conclusions: Preoperative CTC testing is a reliable indicator of whether HCC patients received TACE preoperatively. CTC positivity was associated with early tumor recurrence, and preoperative TACE could reduce early recurrence and long-term prognosis in CTC-positive patients.

Sequence-Based Genomic Analysis Reveals Transmission of Antibiotic Resistance and Virulence among Carbapenemase-Producing Klebsiella pneumoniae Strains.

Carbapenemase-producing Klebsiella pneumoniae (CP-Kpn) are a major concern for nosocomial infections. We previously reported an intensive care unit (ICU) outbreak of CP-Kpn. This study investigated the transmission pattern and genetic characteristic of CP-Kpn in the hospital during the outbreak period. Whole-genome sequencing was retrospectively performed on 173 CP-Kpn isolates. Pairwise single-nucleotide polymorphism (SNP) distances were calculated to determine SNP thresholds for clustering. Plasmids and mobile genome elements (MGEs) were identified through short- and long-read sequencing. Strains were classified into three groups, sequence type 11 (ST11) (86.12%), ST15 (9.83%), and other ST. An SNP threshold of 16 revealed a 66.47% clustering rate. ICU admission and meropenem use proportions were significantly higher in clustered patients than in unique patients. MGE distribution was consistent with the phylogenetic tree. Of the isolates, 53.18% were CP-Kpn with hypervirulence genes. We identified five plasmids carrying virulence genes, and four of them have not been previously reported. Clonal transmission was the main cause of CP-Kpn infections in the hospital. Multidrug resistance genes and MGE variations were correlated with clustering. Finally, four novel plasmids carrying virulence genes were identified. The findings highlight the control of CR-Kpn transmission through prevention measures to reduce nosocomial infections. IMPORTANCE In this study, we combined genomic and epidemiological analyses and defined an optimal cutoff value for SNP difference that could be used to aid investigation in tertiary hospital in China. We revealed clonal transmission was the main cause of CP-Kpn infections in the hospital and identified four novel plasmids carrying virulence genes. Our results strongly suggested that dominant CP K. pneumoniae strains lead to outbreaks and described different evolutionary patterns of plasmids carrying multidrug resistance and virulence genes.

Safety and efficacy of pegylated recombinant human granulocyte colony-stimulating factor during concurrent chemoradiotherapy for small-cell lung cancer: a retrospective, cohort-controlled trial.

OBJECTIVE: To investigate pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) safety and efficacy in preventing hematological toxicity during concurrent chemoradiotherapy (CCRT) for small-cell lung cancer (SCLC). METHODS: We retrospectively assessed 80 SCLC patients treated with CCRT from January 2013 to December 2018 who received PEG-rhG-CSF within 48 hours after the end of chemotherapy, defined as prophylactic use, as the experimental group. An additional 80 patients who were not treated with PEG-rhG-CSF were matched 1:1 by the propensity score matching method and served as the control group. The main observations were differences in hematological toxicity, neutrophil changes, febrile neutropenia (FN) incidence and adverse reactions. Progression-free survival (PFS) and overall survival (OS) were analyzed with regular assessment and follow-up. RESULTS: The leukocyte, neutrophil, erythrocyte, and platelet counts and hemoglobin level decreased after CCRT, but the experimental group had slightly higher leukocyte and neutrophil counts than the control group (P < 0.05). The incidences of grade III-IV leukopenia (18.75% vs. 61.25%) and neutropenia (23.75% vs. 67.5%) in the experimental group were significantly lower than those in the control group (P < 0.05). The absolute neutrophil count was 4.17 ± 0.79 (× 109/L) on day 1 and peaked 6.81 ± 2.37 (× 109/L) on day 10 in the experimental group; the value in the control group was 2.81 ± 0.86 (× 109/L) on day 1. It decreased significantly and reached the minimum 0.91 ± 0.53 (× 109/L) on day 10 (P < 0.05). The experimental group had a lower FN incidence than the control group (P < 0.05). There was also no significant acute esophagitis or pulmonary toxicity. The treatment had no significant effect on PFS (11.4 months vs. 8.7 months, P = 0.958) or OS (23.9 months vs. 17.3 months, P = 0.325) over an 18.6-month median follow-up time. CONCLUSION: PEG-rhG-CSF has good efficacy and safety in preventing hematological toxicity in SCLC patients during CCRT and has no significant effects on PFS or OS.

Recurrence and Prognostic Value of Circulating Tumor Cells in Resectable Pancreatic Head Cancer: A Single Center Retrospective Study.

Background and Aim: To investigate the effect of preoperative circulation tumor cells (CTCs) on postoperative recurrence and overall survival prognosis of pancreatic head cancer after pancreaticoduodenectomy (PD). Methods: From March 2014 to January 2018, 73 patients with pancreatic head cancer underwent radical resection (R0) in Zhongshan People's Hospital. CTCs in peripheral blood of patients with pancreatic head cancer were detected by "Cyttel" method before PD. Seventy-three patients were divided into positive and negative groups according to the positive criteria. To explore the relationship between the clinical data of CTCs and disease-free survival (DFS) and overall survival (OS). Cox proportional hazards model was used to analyzing the risk factors affecting the postoperative recurrence and the survival prognosis of patients. Results: 41 patients (56.2%) were in the CTC-positive group. Preoperative CTCs were correlated with tumor vascular invasion, CA199 level and postoperative liver metastasis (P < 0.05). Preoperative CTC-positive, lymph node metastasis, vascular invasion, and nerve invasion were independent risk factors for DFS (P < 0.05). Preoperative CTC-positive, tumor diameter > 2 cm and vascular invasion were independent risk factors for OS of patients (P < 0.05). Conclusion: The detection of CTCs before PD is an important factor affecting the DFS and OS of pancreatic head cancer, which is significant in guiding clinical work.

Identification and characterization of nontuberculous mycobacteria isolated from suspected pulmonary tuberculosis patients in eastern china from 2009 to 2019 using an identification array system.

OBJECTIVE: Nontuberculous mycobacteria (NTM) species are increasingly being isolated and have become a key factor affecting public health by causing pulmonary diseases. Most NTM species do not respond to conventional tuberculosis (TB) drugs. This study aimed to identify NTM isolated from suspected pulmonary TB patients from the Zhejiang province and analyze their distribution in the region. METHODS: A total of 1,113 NTM isolates from patients suspected to be suffering from acid-fast bacilli-positive tuberculosis were identified at the species level, using the CapitalBio Mycobacterium identification array and polymerase chain reaction amplification and sequencing of 16S-23S gene internal transcribed spacer (ITS), 16S rRNA, and hsp65. RESULTS: Of the 23,138 isolates, we identified 1,102 NTM (4.8%), mainly including Mycobacterium intracellulare (54.81%, 604/1,102), M. chelonae-M. abscessus (16.52%, 182/1,102), M. avium (13.16%, 145/1,102), M. kansasii (8.17%, 90/1,102), and M. gordonae (3.27%, 36/1,102). CONCLUSION: The distribution of NTM species observed in patients with suspected pulmonary tuberculosis provides guidance for the diagnosis and treatment of NTM pulmonary diseases.