Detection on integron carried gene cassettes from pathogens by loop mediated isothermal amplification assays.

In this study, a number of frequently detected gene cassettes from bacterial integrons have been detected and characterized by rapid and simple loop-mediated isothermal amplification (LAMP) assays. Six gene cassettes commonly found in class 1 integrons were studied, including dfrA12, dfrA17, aadA2, aadA5, orfF, and blaVIM2. Primers design, sensitivity, specificity, optimization of each LAMP assay, as well as application of the developed 6 individual LAMP assays on a large scale of bacteria, had been conducted. The optimal amplification was obtained with temperature as 65 °C, reaction time span as 45 min and volume as 25 µl. For application, 272 isolates with various gene cassettes yielded expectable positive amplicons and other 685 integron-negative bacteria showed negative results for the LAMP assays, totaling 100% detection rate and specificity.

Study on the excision and integration mediated by class 1 integron in Enterococcus faecalis.

Recognized as a mobile genetic element, integron is correlated to the excision and integration of exogenous genes, especially bacterial resistance genes. However, most of the investigations focused on Gram-positive bacteria with few exceptions. In this study, Enterococcus faecalis was selected to investigate the excision and integration of class 1 integron. A total of eight plasmids were subjected to establish the transformants for excision and integration test. As results showed, positive excision assay was observed, which had been confirmed by the further integration assays and PCR amplification. The observation of class 1 integron mediated excision and integration of various exogenous antibiotics resistance genes should raise the attention of integrons as novel antibiotic resistance determinant in Gram-positive bacteria, especially in Enterococcus.

First report of novel genetic array aacA4-blaIMP-25-oxa30-catB3 and identification of novel metallo-ß-lactamase gene blaIMP25: A Retrospective Study of antibiotic resistance surveillance on Psuedomonas aeruginosa in Guangzhou of South China, 2003-2007.

Carbapenem, imipenem and meropenem have been broadly prescribed contributing to the global occurrence and prevalence of carbapenem resistance in Psuedomonas aeruginosa, and the associated resistance genotypes remains clinically significant. A retrospective surveillance had been conducted on 499 P. aeruginosa isolates in South China during 2003-2007, including antimicrobial resistance and characterization of MBLs on carbapenem-resistant strains. One hundred and sixty-four out of 499 strains were carbapenem-resistant, with 11, 4 and 5 strains positive for blaIMP-9, blaIMP-25 and blaVIM-2, respectively. Sixteen out of 20 isolates were positive for intI1 and contained identical flanking regions (as indicated in KM384735), and all tested isolates containing the qacE△1-sul1 of the typical 3'-conserved region. A novel blaIMP-25 metallo-ß-lactamase and a genetic array of aacA4-blaIMP-25-oxa30-catB3 have been discovered from this retrospective surveillance on antimicrobial resistance of P. aeruginosa.

Microbial communities, functional, and flavor differences among three different-colored high-temperature Daqu: A comprehensive metagenomic, physicochemical, and electronic sensory analysis.

High-temperature Daqu (HTD) is the starter for producing sauce-flavor Baijiu, with different-colored Daqu (white, yellow, and black) reflecting variations in fermentation chamber conditions, chemical reactions, and associated microbiota. Understanding the relationship between Daqu characteristics and flavor/taste is challenging yet vital for improving Baijiu fermentation. This study utilized metagenomic sequencing, physicochemical analysis, and electronic sensory evaluation to compare three different-colored HTD and their roles in fermentation. Fungi and bacteria dominated the HTD-associated microbiota, with fungi increasing as the fermentation temperature rose. The major fungal genera were Aspergillus (40.17%) and Kroppenstedtia (21.16%), with Aspergillus chevalieri (25.65%) and Kroppenstedtia eburnean (21.07%) as prevalent species. Microbial communities, functionality, and physicochemical properties, particularly taste and flavor, were color-specific in HTD. Interestingly, the microbial communities in different-colored HTDs demonstrated robust functional complementarity. White Daqu exhibited non-significantly higher α-diversity compared to the other two Daqu. It played a crucial role in breaking down substrates such as starch, proteins, hyaluronic acid, and glucan, contributing to flavor precursor synthesis. Yellow Daqu, which experienced intermediate temperature and humidity, demonstrated good esterification capacity and a milder taste profile. Black Daqu efficiently broke down raw materials, especially complex polysaccharides, but had inferior flavor and taste. Notably, large within-group variations in physicochemical quality and microbial composition were observed, highlighting limitations in color-based HTD quality assessment. Water content in HTD was associated with Daqu flavor, implicating its crucial role. This study revealed the complementary roles of the three HTD types in sauce-flavor Baijiu fermentation, providing valuable insights for product enhancement.

Value of transrectal contrast-enhanced ultrasound with clinical indicators in the prediction of bone metastasis in prostate cancer.

Background: Transrectal contrast-enhanced ultrasound is an examination that can be used to diagnose and characterize prostate cancer by displaying tissue blood perfusion. To explore the value of transrectal contrast-enhanced ultrasound combined with clinical factors in predicting prostate cancer bone metastasis. Methods: We retrospectively analyzed transrectal contrast-enhanced ultrasound examination data, imaging examination data [single-photon emission computed tomography (SPECT)/computed tomography (CT), CT, magnetic resonance imaging (MRI), and/or bone scan], clinical laboratory data, and pathological Gleason score of 163 patients with prostate cancer. They were randomly divided into the modeling and validation data sets. A model for predicting prostate cancer bone metastasis was established by logistic regression in the modeling data set. The differentiation, consistency, and benefits of the model were verified using the validation data set. A nomogram of the prediction model for bone metastasis of prostate cancer was drawn. Results: Among 163 patients with prostate cancer, 65 had bone metastasis. Total prostate-specific antigen, alkaline phosphatase, and the transrectal contrast-enhanced ultrasound parameter area under the curve were independently associated with prostate cancer bone metastasis, with OR values of 2.845, 2.839, and 1.004, respectively. The area under the receiver operating characteristic curve of the prostate cancer bone metastasis prediction model was 0.804. In the training set, using a cutoff of 0.659, sensitivity was 52.8%, and specificity was 95.7%. In the validation set, using a cutoff of 0.659, sensitivity was 58.6%, and specificity was 98.1%. The area under the curve of the validation set was 0.799. The Hosmer-Lemeshow goodness-of-fit test showed that the calibration ability of the validation set was not statistically different from the training set (P=0.136). The decision curve analysis showed that the model had high benefits. Conclusions: The nomogram that includes the transrectal contrast-enhanced ultrasound parameter area under the curve and the clinical parameters total prostate-specific antigen, and alkaline phosphatase can be used to personalize the risk of prostate cancer bone metastases.

Verification and application of a modified carbapenem inactivation method (mCIM) on Pseudomonas aeruginosa: a potential screening methodology on carbapenemases phenotype in Bacillus cereus.

Antimicrobial resistance (AMR) has been a leading issue for human health globally threatening the achievement of several of the Sustainable Development Goals (SDGs). Originated from Bacillus cereus, carbapenemases phenotype has been considered to be a major concern in AMR. In this study, the AMR identification rate of P. aeruginosa isolates and infections in FAHJU showed an obvious upward trend from 2012 to 2016. All 88 carbapenem-resistant P. aeruginosa strains were screened for carbapenemase phenotype by modified Carbapenem Inactivation Method (mCIM), and these results of mCIM were compared with traditional PCR results. The isolates of P. aeruginosa and infected patients showed obvious upward trend from 2012 to 2016. The drug resistance to common clinical antibiotics was serious that the clinical rational use of antibiotics should be strengthened, which is in accordance with the Global Antimicrobial Resistance and Use Surveillance System (GLASS) report. In comparison, the results of mCIM showed that 18 out of 88 CRPA strains were carbapenemase positive, which were completely consistent with the results yielded by PCR method. Therefore, it is convinced that this mCIM methodology is a simple and quick method for detected carbapenemases producing P. aeruginosa and has a potential capability in carbapenemases phenotype of pathogen like B. cereus, which will undoubtedly aid in the AMR therapy.

Standardized Uptake Value Using Thyroid Quantitative SPECT/CT for the Diagnosis and Evaluation of Graves' Disease: A Prospective Multicenter Study.

The clinical applications of the quantitative single photon emission computed tomography (SPECT)/computed tomography (CT) are being expanded to a variety of fields of nuclear medicine. However, clinical application of quantitative SPECT/CT for the evaluation of Graves' disease (GD) still needs further investigation. Our aim was to investigate the feasibility of standard uptake value (SUV) of the thyroid for the clinical diagnosis and evaluation of GD. In this prospective multicenter study, 116 patients diagnosed with GD (Graves group) and 74 healthy volunteers (control group) were enrolled from 8 different hospitals. All patients underwent technetium pertechnetate (99mTcO4 -) SPECT/CT imaging with Q.Metrix quantitative software and 24-hour thyroid radioactive iodine uptake (24h-RAIU) test. The SUVmax and SUVmean in Graves group were significantly higher than those of control group (P<0.01). Cut-off values of SUVmax and SUVmean to predict GD were 231.425 and 116.66 by ROC curves, respectively. The SUVmax and SUVmean in Graves patients were significantly related to serum thyroxine level with correlation coefficient of 0.493 and 0.512 for FT3 and 0.449 and 0.464 for FT4, respectively (all P<0.01). Additionally, the SUVmax and SUVmean in GD positively correlated with 24h-RAIU with a coefficient of 0.832 and 0.830, respectively (P<0.01). The volumes determined by Q.Metrix (35.65 ± 20.56ml) of 72 subjects also positively correlated with that from ultrasound (36.67 ± 21.00ml) with a coefficient of 0.927 (P<0.01). SUV measurements derived from thyroid SPECT/CT may be useful for the clinical diagnosis and evaluation of GD.

Measurement and Evaluation of Quantitative Performance of PET/CT Images before a Multicenter Clinical Trial.

To ensure the reliability of the planned multi-center clinical trial, we assessed the consistence and comparability of the quantitative parameters of the eight PET/CT units that will be used in this trial. PET/CT images were scanned using a PET NEMA image quality phantom (Biodex) on the eight units of Discovery PET/CT 690 from GE Healthcare. The scanning parameters were the same with the ones to be used in the planned trial. The 18F-NaF concentration in the background was 5.3 kBq/ml, while the ones in the spheres of diameter 37 mm, 22 mm, 17 mm and 10 mm were 8:1 as to that of the background and the ones in the spheres of diameter 28 mm and 13 mm were 0 kBq/ml. The consistency of hot sphere recovery coefficient (HRC), cold sphere recovery coefficient (CRC), hot sphere contrast (QH) and cold sphere contrast (Qc) among these 8 PET/CTs was analyzed. The variation of the main quantitative parameters of the eight PET/CT systems was within 10%, which is acceptable for the clinical trial.