Comparing the 7th and 8th editions of UICC/AJCC staging system for nasopharyngeal carcinoma in the IMRT era.

BACKGROUND: To compare the prognostic value of 7th and 8th editions of the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system for patients with nonmetastatic nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy and simultaneous integrated boost- intensity-modulated radiation therapy (SIB-IMRT). METHODS: Patients with NPC (n = 300) who received SIB-IMRT were included. Survival by T-classification, N-classification, and stage group of each staging system was assessed. RESULTS: For T-classification, nonsignificant difference was observed between T1 and T3 and between T2 and T3 disease (P = 0.066 and 0.106, respectively) for overall survival (OS) in the 7th staging system, whereas all these differences were significant in the 8th staging system (all P < 0.05). The survival curves for disease-free survival (DFS) and locoregional recurrence-free survival (LRRFS) in both staging systems were similar, except for the comparison of T2 and T4 disease for LRRFS (P = 0.070 for 7th edition; P = 0.011 for 8th edition). For N-classification, significant differences were observed between N2 and N3 diseases after revision (P = 0.046 and P = 0.043 for OS and DFS, respectively). For staging system, no significant difference was observed between IVA and IVB of 7th edition. CONCLUSION: The 8th AJCC staging system appeared to have superior prognosis value in the SIB-IMRT era compared with the 7th edition.

Mechanisms of gastrointestinal toxicity in neuromyelitis optica spectrum disorder patients treated with mycophenolate mofetil: insights from a mouse model and human study.

Mycophenolate mofetil (MMF) is commonly utilized for the treatment of neuromyelitis optica spectrum disorders (NMOSD). However, a subset of patients experience significant gastrointestinal (GI) adverse effects following MMF administration. The present study aims to elucidate the underlying mechanisms of MMF-induced GI toxicity in NMOSD. Utilizing a vancomycin-treated mouse model, we compiled a comprehensive data set to investigate the microbiome and metabolome in the GI tract to elucidate the mechanisms of MMF GI toxicity. Furthermore, we enrolled 17 female NMOSD patients receiving MMF, who were stratified into non-diarrhea NMOSD and diarrhea NMOSD (DNM) groups, in addition to 12 healthy controls. The gut microbiota of stool samples was analyzed using 16S rRNA gene sequencing. Vancomycin administration prevented weight loss and tissue injury caused by MMF, affecting colon metabolomes and microbiomes. Bacterial ß-glucuronidase from Bacteroidetes and Firmicutes was linked to intestinal tissue damage. The DNM group showed higher alpha diversity and increased levels of Firmicutes and Proteobacteria. The ß-glucuronidase produced by Firmicutes may be important in causing gastrointestinal side effects from MMF in NMOSD treatment, providing useful information for future research on MMF. IMPORTANCE: Neuromyelitis optica spectrum disorder (NMOSD) patients frequently endure severe consequences like paralysis and blindness. Mycophenolate mofetil (MMF) effectively addresses these issues, but its usage is hindered by gastrointestinal (GI) complications. Through uncovering the intricate interplay among MMF, gut microbiota, and metabolic pathways, this study identifies specific gut bacteria responsible for metabolizing MMF into a potentially harmful form, thus contributing to GI side effects. These findings not only deepen our comprehension of MMF toxicity but also propose potential strategies, such as inhibiting these bacteria, to mitigate these adverse effects. This insight holds broader implications for minimizing complications in NMOSD patients undergoing MMF therapy.

Epstein-Barr virus DNA change level combined with tumor volume reduction ratio after inductive chemotherapy as a better prognostic predictor in locally advanced nasopharyngeal carcinoma.

BACKGROUND: To explore the prognosis predicting ability of the combined factors, Epstein-Barr virus DNA change level (EBVCL) and tumor volume reduction ratio (TVRR) after inductive chemotherapy (IC), in locally advanced nasopharyngeal carcinoma (LANPC). METHODS: From 2010 to 2018, 299 LANPC patients were included in this retrospective study. Receiver operating characteristic (ROC) curve analysis was performed to acquire the best critical values. According to the best critical values of EBVCL and TVRR, patients were stratified into low- and high-risk groups. Kaplan-Meier and ROC curve analyses were utilized to verify the prognostic ability of the new predictor (EBVCL+TVRR). The prognostic values among EBVCL+TVRR, EBVCL, TVRR, TNM stage, and the RECIST 1.1 criteria were compared by ROC curve. The primary end points were overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional failure-free survival (LRFFS). RESULTS: ROC curve analyses of TVRR on three-year survival showed the best critical values of TVRR was 32.72% for OS, 30.21% for PFS and LRFFS, 29.87% for DMFS. The best critical value of EBVCL was 127 copies/ml for OS, and 87.7 copies/ml for PFS, DMFS, and LRFFS. The three-year OS, PFS, DMFS, and LRFFS for low- and high-risk groups were 97.7% versus 78.3% (hazard ratio [HR] = 0.2398; 95% confidence interval [CI]: 0.1277-0.4502; p < 0.0001), 91.1% versus 60.9% (HR = 0.3294; 95% CI: 0.2050-0.5292; p < 0.0001), 94.2% versus 68.7% (HR = 0.2413; 95% CI: 0.1284-0.4535; p < 0.0001) and 97.8% versus 77.9% (HR = 0.3078; 95% CI: 0.1700-0.5573; p = 0.0001), respectively. The maximal area under ROC curve of EBVCL+TVRR, EBVCL, TVRR, TNM stage, and RECIST 1.1 criteria for three-year OS was 0.829, 0.750, 0.711, 0.555, and 0.605, respectively. CONCLUSION: The new-developed indicator (EBVCL+TVRR) could better predict the LANPC patient's survival after IC compared with TNM stage system or RECIST 1.1 criteria.

MALDI-TOF MS for rapid detection and differentiation between Tet(X)-producers and non-Tet(X)-producing tetracycline-resistant Gram-negative bacteria.

The extensive use of tetracycline antibiotics has led to the widespread presence of tetracycline-resistance genes in Gram-negative bacteria and this poses serious threats to human and animal health. In our previous study, we reported a method for rapid detection of Tet(X)-producers using MALDI-TOF MS. However, there have been multiple machineries involved in tetracycline resistance including efflux pump, and ribosomal protection protein. Our previous demonstrated the limitation in probing the non-Tet(X)-producing tetracycline-resistant strains. In this regard, we further developed a MALDI-TOF MS method to detect and differentiate Tet(X)-producers and non-Tet(X)-producing tetracycline-resistant strains. Test strains were incubated with tigecycline and oxytetracycline in separate tubes for 3 h and then analyzed spectral peaks of tigecycline, oxytetracycline, and their metabolite. Strains were distinguished using MS ratio for [metabolite/(metabolite+ tigecycline or oxytetracycline)]. Four control strains and 319 test strains were analyzed and the sensitivity was 98.90% and specificity was 98.34%. This was consistent with the results obtained from LC-MS/MS analysis. Interestingly, we also found that the reactive oxygen species (ROS) produced by tetracycline-susceptible strains were able to promote the degradation of oxytetracycline. Overall, the MALDITet(X)-plus test represents a rapid and reliable method to detect Tet(X)-producers, non-Tet(X)-producing tetracycline-resistant strains, and tetracycline-susceptible strains.

Emergence of fosA3 and bla CTX-M- 14 in Multidrug-Resistant Citrobacter freundii Isolates From Flowers and the Retail Environment in China.

We examined the prevalence and transmission of the fosA3 gene among Citrobacter freundii isolates from flowers and the retail environments. We identified 11 fosfomycin-resistant C. freundii strains (>256 µg/mL) from 270 samples that included petals (n = 7), leaves (n = 2), dust (n = 1) and water (n = 1). These 11 isolates were multidrug-resistant and most were simultaneously resistant to fosfomycin, cefotaxime, ciprofloxacin and amikacin. Consistently, all 11 isolates also possessed bla CTX-M- 14, bla CMY- 65 / 122, aac(6')-Ib-cr, qnrS1, qnrB13/6/38 and rmtB. These fosA3-positive isolates were assigned to two distinct PFGE patterns and one (n = 9) predominated indicating clonal expansion of fosA3-positive isolates across flower markets and shops. Correspondingly, fosA3 was co-transferred with bla CTX-M- 14 via two plasmid types by conjugation possessing sizes of 110 kb (n = 9) and 260 kb (n = 2). Two representatives were fully sequenced and p12-1 and pS39-1 possessed one and two unclassified replicons, respectively. These plasmids shared a distinctive and conserved backbone in common with fosA3-carrying C. freundii and other Enterobacteriaceae from human and food animals. However, the fosA3-bla CTX-M- 14-containing multidrug resistance regions on these untypable plasmids were highly heterogeneous. To the best of our knowledge, this is the first report of fosA3 and bla CTX-M- 14 that were present in bacterial contaminants from flower shops and markets. These findings underscore a public health threat posed by untypable and transferable p12-1-like and pS39-1-like plasmids bearing fosA3-bla CTX-M- 14 that could circulate among Enterobacteriaceae species and in particular C. freundi in environmental isolates.

Duck wastes as a potential reservoir of novel antibiotic resistance genes.

Overuse of antibiotics in animal husbandry has led to an increase of antibiotic resistance microorganisms as well as antibiotic-resistance genes (ARGs). Duck farming in China is practiced on a large and diverse scale and the overuse of antibiotics in this field is gaining attention recently. We evaluated the diversity of ARGs from five duck farms using a functional metagenomic approach and constructed five libraries. A total of seventy-six resistant determinants were identified, of which sixty-one were gene variants or novel genes. The novel genes contained five ß-lactamase-encoding genes designated as blaDWA1, blaDWA2, blaDWA3, blaDWA4 and blaDWB1, respectively, and two genes conferring resistance to fosfomycin designated as fosA-like1 and fosA-like2. Three of the five ß-lactamase-encoding genes were further identified as extended-spectrum ß-lactamases (ESBL) that can hydrolyze both penicillins and cephalosporins. Besides, two of the five ß-lactamase-encoding genes were associated with mobile genetic elements, indicating a high potential for transfer of the genes to other bacterial hosts. The two novel fosA-like genes were able to increase the MICs of the test Escherichia coli strain from 2 µg/mL to as high as 256 µg/mL(up to 128-fold increase). Our study provides a reference for ARGs prevalence in duck farm wastes and implies that they are an important resistome reservoir, especially for novel ARGs with high spread potential.

The comparison of prognostic value of tumour volumetric regression ratio and RECIST 1.1 criteria after induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma.

PURPOSE: To compare the prognostic value of the sum volumetric regression ratio (SVRR) of the primary tumour and metastatic lymph nodes with treatment response based on RECIST 1.1 criteria after induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: A total of 117 stage III-IVA NPC patients treated with induction chemotherapy followed by concurrent chemoradiotherapy (CCRT) were retrospectively reviewed. The SVRR and the treatment response based on RECIST 1.1 were measured using contrast-enhanced computed tomography (CT) localisations before and after induction chemotherapy. The receiver operating characteristic (ROC) curve analysis was used to identify the optimal cutoff point of the SVRR and compare the prognostic value of the SVRR and RECIST 1.1criteria. RESULTS: The optimal cutoff points of SVRR for progression-free survival (PFS), locoregional failure-free survival (LRFFS) and distant metastasis-free survival (DMFS) were all 25.15%, while for overall survival (OS) it was 16.63%. The area under the ROC curve (AUC) of optimal cutoff points of SVRR was superior than that of RECIST 1.1 for PFS (AUC: 0.716 vs. 0.578; P = 0.0022), LRFFS (AUC: 0.700 vs. 0.574; P = 0.0080) and DMFS (AUC: 0.736 vs. 0.606; P = 0.0053), respectively. The 3-year PFS, DMFS and OS rates for SVRR less than vs. greater than or equal to the cutoff points were 55.8% vs. 92.2% (P < 0.001, hazard ratio (HR): 0.209, 95% confidence interval (CI): 0.091-0.480), 59.7% vs. 96.7% (P < 0.001, HR: 0.120, 95% CI: 0.043-0.336) and 66.7% vs. 98.1% (P < 0.001, HR: 0.069, 95% CI: 0.014-0.342), while the responses [stable disease (SD), partial response (PR)] based on RECIST 1.1 were not significantly associated with 3-year survival rates. Multivariate analysis indicated that SVRR was an independent prognostic factor for PFS, DMFS and OS (all P < 0.05). CONCLUSIONS: The sum volumetric regression ratio and response based on RECIST 1.1 were related to the prognosis in locoregionally advanced NPC after induction chemotherapy. Sum volumetric regression ratio is an independent outcome predictor for survival in locoregionally advanced NPC, playing a better prognostic role than RECIST 1.1.

A Four-Hour Carbapenem Inactivation Method (CIM B.S ) Using Bacillus stearothermophilus as Indicator Strain.

Objectives: There is an urgent need for accurate and fast diagnostic tests to identify carbapenemase-producing bacteria. Here we used Bacillus stearothermophilus as an indicator strain in the format of the carbapenem inactivation method (CIM) procedure to develop a rapid carbapenemase phenotype detection method: CIMB.S. Methods: The CIMB.S test was derived from the mCIM, where B. stearothermophilus replaced Escherichia coli as the indicator strain. The test bacteria were incubated in the presence of imipenem for 30 min, and then, aliquots were placed on colorimetric plates, and incubation was continued for 3.5 h at 60°C. We examined 134 clinical strains to evaluate the CIMB.S performance. Results: The CIMB.S can be completed in 4 h, and we successfully identified 38/39 (97.4%) carbapenemase-producing Enterobacteriaceae, including 17/18 (94.4%) carbapenemase-producing Pseudomonas aeruginosa and 18/19 (94.7%) carbapenemase-producing Acinetobacter baumannii. All non-carbapenemase producers we tested were negative and included Enterobacteriaceae (n = 36), P. aeruginosa (n = 17), and A. baumannii (n = 5). Conclusions: The CIMB.S test is a rapid carbapenemase phenotype detection method requiring only 4 h of total work time and displays high sensitivity and specificity.

Rapid Detection of High-Level Tigecycline Resistance in Tet(X)-Producing Escherichia coli and Acinetobacter spp. Based on MALDI-TOF MS.

The emergence and spread of the novel mobile Tet(X) tetracycline destructases confer high-level tigecycline and eravacycline resistance in Escherichia coli and Acinetobacter spp. and pose serious threats to human and animal health. Therefore, a rapid and robust Tet(X) detection assay was urgently needed to monitor the dissemination of tigecycline resistance. We developed a rapid and simple assay to detect Tet(X) producers in Gram-negative bacteria based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). This MALDITet(X) test was based on the inactivation of tigecycline by a Tet(X)-producing strain after a 3-h incubation of bacterial cultures with tigecycline. Culture supernatants were analyzed using MALDI-TOF MS to identify peaks corresponding to tigecycline (586 ± 0.2 m/z) and a tigecycline metabolite (602 ± 0.2 m/z). The results were calculated using the MS ratio [metabolite/(metabolite + tigecycline)]. The sensitivity of the MALDITet(X) test with all 216 test strains was 99.19%, and specificity was 100%. The test can be completed within 3 h. Overall, the MALDITet(X) test is an accurate, rapid, cost-effective method for the detection of Tet(X)-producing E. coli and Acinetobacter spp. by determining the unique peak of an oxygen-modified derivative of tigecycline.

Genetic diversity and characteristics of high-level tigecycline resistance Tet(X) in Acinetobacter species.

BACKGROUND: The recent emergence and dissemination of high-level mobile tigecycline resistance Tet(X) challenge the clinical effectiveness of tigecycline, one of the last-resort therapeutic options for complicated infections caused by multidrug-resistant Gram-negative and Gram-positive pathogens. Although tet(X) has been found in various bacterial species, less is known about phylogeographic distribution and phenotypic variance of different genetic variants. METHODS: Herein, we conducted a multiregional whole-genome sequencing study of tet(X)-positive Acinetobacter isolates from human, animal, and their surrounding environmental sources in China. The molecular and enzymatic features of tet(X) variants were characterized by clonal expression, microbial degradation, reverse transcription, and gene transfer experiments, while the tet(X) genetic diversity and molecular evolution were explored by comparative genomic and Bayesian evolutionary analyses. RESULTS: We identified 193 tet(X)-positive isolates from 3846 samples, with the prevalence ranging from 2.3 to 25.3% in nine provinces in China. The tet(X) was broadly distributed in 12 Acinetobacter species, including six novel species firstly described here. Besides tet(X3) (n = 188) and tet(X4) (n = 5), two tet(X5) variants, tet(X5.2) (n = 36) and tet(X5.3) (n = 4), were also found together with tet(X3) or tet(X4) but without additive effects on tetracyclines. These tet(X)-positive Acinetobacter spp. isolates exhibited 100% resistance rates to tigecycline and tetracycline, as well as high minimum inhibitory concentrations to eravacycline (2-8 µg/mL) and omadacycline (8-16 µg/mL). Genetic analysis revealed that different tet(X) variants shared an analogous ISCR2-mediated transposon structure. The molecular evolutionary analysis indicated that Tet(X) variants likely shared the same common ancestor with the chromosomal monooxygenases that are found in environmental Flavobacteriaceae bacteria, but sequence divergence suggested separation ~ 9900 years ago (7887 BC), presumably associated with the mobilization of tet(X)-like genes through horizontal transfer. CONCLUSIONS: Four tet(X) variants were identified in this study, and they were widely distributed in multiple Acinetobacter spp. strains from various ecological niches across China. Our research also highlighted the crucial role of ISCR2 in mobilizing tet(X)-like genes between different Acinetobacter species and explored the evolutionary history of Tet(X)-like monooxygenases. Further studies are needed to evaluate the clinical impact of these mobile tigecycline resistance genes.

Clonal Spread of 16S rRNA Methyltransferase-Producing Klebsiella pneumoniae ST37 with High Prevalence of ESBLs from Companion Animals in China.

We screened 30 Klebsiella pneumoniae isolates from dogs and cats at a single animal hospital in Guangdong Province, China. Among them, 12 K. pneumoniae strains possessed high-level resistance to amikacin and gentamicin and these were screened for 16S rRNA methyltransferase (16S-RMTase) genes. And then the genes positive isolates were detected for ESBLs (extended spectrum ß-lactamases) and analyzed by pulsed-field gel electrophoresis, multilocus sequence typing, PCR-based replicon typing and plasmid analysis. The genetic profiles of rmtB were also determined by PCR mapping. The twelve 16S-RMTase gene-positive isolates were rmtB (11/30) and armA (2/30) with one isolate carrying both genes. Extended spectrum ß-lactamases genes were represented by blaCTX-M-55 (9/12), blaCTX-M-27 (2/12) and blaCTX-M-14 (1/12). The twelve 16S-RMTase containing strains were grouped into five clonal patterns and ST37 was the most prevalent sequence type. Ten rmtB-bearing plasmids conjugated successfully and all belonged to IncN and IncF (F33:A-:B-) incompatibility groups. Nine of the transconjugants carried a 97 kb plasmid and the other harbored both ∼60 and ∼200 kb plasmids. rmtB and blaCTX-M-55 were present on the same plasmid and indicated the co-transfer of these two genes, with the rmtB gene showing highly relevant relationships with IS26 and Tn3. Our findings suggested a high prevalence of 16S-RMTase genes in K. pneumonia ST37 from dogs and cats. Additional studies are needed to trace the evolutionary path of this type of resistance among the K. pneumonia isolates, and to determine whether they have been transferred to humans.