Prevalence and antimicrobial resistance of Salmonellaisolates from goose farms in Northeast China

BACKGROUND

Salmonella is one of the most important enteric pathogenic bacteria that threatened poultry health.

AIMS

This study aimed to investigate the prevalence and antimicrobial resistance of Salmonella isolates in goose farms.

METHODS

A total of 244 cloacal swabs were collected from goose farms to detect Salmonella in Northeast China. Antimicrobial susceptibility, and resistance gene distribution of Salmonella isolates were investigated.

RESULTS

Twenty-one Salmonella isolates were identified. Overall prevalence of Salmonella in the present study was 8.6%. Among the Salmonella isolates, the highest resistance frequencies belonged to amoxicillin (AMX) (85.7%), tetracycline (TET) and trimethoprim/sulfamethoxazole (SXT) (81%), followed by chloramphenicol (CHL) (76.2%), florfenicol (FLO) (71.4%), kanamycin (KAN) (47.6%), and gentamycin (GEN) (38.1%). Meanwhile, only 4.8% of the isolates were resistant to ciprofloxacin (CIP) and cefotaxime (CTX). None of the isolates was resistant to cefoperazone (CFP) and colistin B (CLB). Twenty isolates (95%) were simultaneously resistant to at least two antimicrobials. Ten resistance genes were detected among which the bla _TEM-1, cmlA, aac(6')-Ib-cr, sul1, sul2, sul3, and mcr-1.1 were the most prevalent, and presented in all 21 isolates followed by tetB (20/21), qnrB (19/21), and floR (15/21).

CONCLUSION

Results indicated that Salmonella isolates from goose farms in Northeast China exhibited multi-drug resistance (MDR), harboring multiple antimicrobial resistance genes. Our results will be useful to design prevention and therapeutic strategies against Salmonella infection in goose farms.

Dynamic characteristics of AHLs-secreting strain Aeromonas sp. A-L2 and its bioaugmentation during quinoline biodegradation

AIMS

In order to probe a more environmentally friendly method of pollutant treatment based on microbial bioaugmentation and quorum sensing (QS) effects.

METHODS AND RESULTS

The dynamic characteristics and QS effects of the acylated homoserine lactones (AHLs)-secreting strain Aeromonas sp. A-L2 (A-L2), which was isolated from the activated sludge system, was discussed. According to the liquid chromatography-mass spectrometry results, N-butyryl-homoserine lactone (C4-HSL) and N-hexanoyl-homoserine lactone (C6-HSL) were the major AHLs secreted by strain A-L2, and the swarming of strain Ochrobactrum sp. LC-1 (LC-1) was induced by these compounds. The extracellular polymeric substance secretion of the strain LC-1 was mainly led by C6-HSL, and the biofilm formation ability was mainly influenced by C6-HSL or C4-HSL (60 μg l^-1 ). The optimal AHLs secretion conditions of strain A-L2 were also studied. Drawing support from the AHLs-secreting strain A-L2 during quinoline degradation by strain LC-1, the degradation time was greatly shortened.

CONCLUSIONS

Hence, AHLs-secreting strain A-L2 can be useful as an AHLs continuous supplier during bioaugmentation and pollutant biodegradation.

SIGNIFICANCE AND IMPACT OF THE STUDY

The bioaugmentation process of strain A-L2 on quinoline biodegradation based on QS effects would lay a certain theoretical and practical significance for large-scale applications.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Recognizing basal cell carcinoma on smartphone-captured digital histopathology images with a deep neural network

BACKGROUND

Pioneering effort has been made to facilitate the recognition of pathology in malignancies based on whole-slide images (WSIs) through deep learning approaches. It remains unclear whether we can accurately detect and locate basal cell carcinoma (BCC) using smartphone-captured images.

OBJECTIVES

To develop deep neural network frameworks for accurate BCC recognition and segmentation based on smartphone-captured microscopic ocular images (MOIs).

METHODS

We collected a total of 8046 MOIs, 6610 of which had binary classification labels and the other 1436 had pixelwise annotations. Meanwhile, 128 WSIs were collected for comparison. Two deep learning frameworks were created. The 'cascade' framework had a classification model for identifying hard cases (images with low prediction confidence) and a segmentation model for further in-depth analysis of the hard cases. The 'segmentation' framework directly segmented and classified all images. Sensitivity, specificity and area under the curve (AUC) were used to evaluate the overall performance of BCC recognition.

RESULTS

The MOI- and WSI-based models achieved comparable AUCs around 0·95. The 'cascade' framework achieved 0·93 sensitivity and 0·91 specificity. The 'segmentation' framework was more accurate but required more computational resources, achieving 0·97 sensitivity, 0·94 specificity and 0·987 AUC. The runtime of the 'segmentation' framework was 15·3 ± 3·9 s per image, whereas the 'cascade' framework took 4·1 ± 1·4 s. Additionally, the 'segmentation' framework achieved 0·863 mean intersection over union.

CONCLUSIONS

Based on the accessible MOIs via smartphone photography, we developed two deep learning frameworks for recognizing BCC pathology with high sensitivity and specificity. This work opens a new avenue for automatic BCC diagnosis in different clinical scenarios. What's already known about this topic? The diagnosis of basal cell carcinoma (BCC) is labour intensive due to the large number of images to be examined, especially when consecutive slide reading is needed in Mohs surgery. Deep learning approaches have demonstrated promising results on pathological image-related diagnostic tasks. Previous studies have focused on whole-slide images (WSIs) and leveraged classification on image patches for detecting and localizing breast cancer metastases. What does this study add? Instead of WSIs, microscopic ocular images (MOIs) photographed from microscope eyepieces using smartphone cameras were used to develop neural network models for recognizing BCC automatically. The MOI- and WSI-based models achieved comparable areas under the curve around 0·95. Two deep learning frameworks for recognizing BCC pathology were developed with high sensitivity and specificity. Recognizing BCC through a smartphone could be considered a future clinical choice.

[Diagnostic value of endoscopic ultrasonography, fibroscan, acoustic radiation pulse imaging, serological index, and their combination for early stage liver cirrhosis]

Objective: To investigate the diagnostic value of endoscopic ultrasonography (EUS), Fibroscan, acoustic radiation force impulse (ARFI), and aspartate aminotransferase-to-platelet ratio (APRI) and their combination for early stage liver cirrhosis. Methods: Three hundred and twenty-two hospitalized patients who had been diagnosed with chronic viral liver disease from March 2016 to April 2018 were included. According to the clinical diagnosis, patients were divided into chronic hepatitis and the early stage liver cirrhosis group (Child-Pugh A grade). All patients were examined by Fibroscan to detect liver stiffness measurement (LSM), ARFI to detect liver virtual touch tissue quantification (VTQ) value, esophagogastroduodenoscopy and EUS to detect esophagogastric varices, laboratory and imaging examination. The index of EUS, Fibroscan, ARFI, and APRI was analyzed and the regression model was established by binary logistic regression, and the diagnostic efficacy of the above index and regression model for early stage of cirrhosis was evaluated by the area under a receiver operating characteristic curve (AUROCs). Results: An early stage cirrhosis group had significantly higher detection rate with EUS (esophagogastric varices), Fibroscan (LSM), ARFI (VTQ) and APRI than chronic hepatitis group [76.7% vs. 10.7%, 10.4 (7.8, 17.3) vs. 6.1 (5.2, 8.4) kPa, 1.71(1.48, 2.07) m/s vs. 1.25(1.14, 1.43) m/s and 0.65 (0.38, 1.15) vs. 0.38(0.26, 0.62), respectively]. The corresponding chi-square test were 140.86, Z = -9.069, Z = -9.948 and Z = -5.764, respectively and the differences were statistically significant (P < 0.01). The areas under the receiver operating characteristic curve and regression model were 0.830 (0.783 ~ 0.877), 0.793 (0.744 ~ 0.841), 0.821 (0.775 ~ 0.868), 0.686 (0.628 ~ 0.744) and 0.947 (0.925 ~ 0.969) for the diagnosis of early stage cirrhosis, respectively. Among them, the regression model of three indices (EUS, LSM and VTQ) had the largest AUROCs (0.947) and the corresponding sensitivity and specificity were 0.878 and 0.867, respectively. Conclusion: The combination of EUS, LSM and ARFI had a superior diagnostic value for early stage liver cirrhosis, and may improve the diagnosis rate and reduce the misdiagnosis rate.

[Analysis on influencing factors that leading to nonspecific responses to indeterminate results of HIV antibodies]

Objective: To identify the influencing factors that leading to nonspecific responses to indeterminate HIV antibody tests, to provide scientific evidence for the differential diagnosis of HIV infection and control strategy. Methods: A case control study was conducted. The samples of HIV antibody indeterminate in confirmed Western blot (WB) tests, but were negative in HIV nucleic acid tests, were collected as HIV antibody indeterminate group from WB results of HIV confirmatory laboratories of Fujian province in 2015-2016. The general population matched group with HIV antibody screening negative samples and WB negative matched group with WB negative samples were selected as the two compared groups by matching gender and age from HIV antibody screening in Fujian province in the same period. Blood concentrations of hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV) antibody, anti-treponema pallidum (TP) antibody, antinuclear antibody (ANA), anti-human T-cell leukemia virus (HTLV) antibody, and alpha-fetoprotein (AFP) were detected by using enzyme-linked immunosorbent assay (ELISA). χ(2) test and multivariate non-conditional logistic regression analysis were performed to identify the influencing factors that leading to nonspecific responses, to indeterminate HIV antibody tests. Results: A total of 13 WB band patterns were observed in 110 HIV antibody indeterminate samples, in which a single p24 band (58.18%, 64/110), a single gp160 band (17.27%, 19/110) and a single p17 band (7.27%, 8/110) were the three most common patterns. The positive rate of anti-TP antibody was significantly higher in HIV antibody indeterminate samples than general population control group and WB negative control group (10.91%, 12/110 vs. 1.77%, 4/226 and 3.64%, 4/110), compared with two control groups (χ(2)=13.627 and 4.314, P<0.05). The positive rate of AFP was significantly higher in HIV antibody indeterminate samples than general population control group (18.18%, 20/110 vs. 0.44%, 1/226, χ(2)=39.736, P<0.05), the different was not significant compared with WB negative control group (18.18%, 20/110 vs. 23.64%, 26/110, χ(2)=0.990, P>0.05) While no significant differences were found between HIV antibody indeterminate group and two control groups in terms of the positive rates of ANA, HBsAg, anti-HCV antibody or anti-HTLV antibody. Conclusions: The influencing factors that leading to nonspecific responses to indeterminate HIV antibody tests appeared complicate, and the anti-TP antibody positivity might be an influencing factor responsible for nonspecific responses to indeterminate HIV antibody tests.

[Role of signaling pathway of long non-coding RNA growth arrest-specific transcript 5/microRNA-200c-3p/angiotensin converting enzyme 2 in the apoptosis of human lung epithelial cell A549 in acute respiratory distress syndrome]

Objective: To investigate whether long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5)/microRNA-200c-3p/angiotensin converting enzyme 2(ACE2) involved in the regulation of the apoptosis of human lung epithelial cell A549 in acute respiratory distress syndrome (ARDS). Methods: ARDS rat models were established and were divided into control, ARDS, ARDS+ pcDNA and ARDS+ pcDNA-GAS5 groups. Six hours after the establishment of ARDS rat model, arterial blood and lung tissues of the rats from the four groups were collected. The changes of partial pressure of oxygen (PO(2)) and partial pressure of CO(2) (PCO(2)) were analyzed and the expression of GAS5 in lung tissue was observed in these groups. Then, A549 cells were divided into control, lipopolysaccharide (LPS), LPS+ pcDNA, LPS+ pcDNA-GAS5, LPS+ pcDNA-GAS5+ pre-NC, LPS+ pcDNA-GAS5+ miR-200c-3p mimic groups. Quantitative real-time PCR (qRT-PCR) was conducted to measure lncRNA GAS5, ACE2 and miR-200c-3p levels. RNA immunoprecipitation and RNA pull-down assay were used to detect the combination between GAS5 and miR-200c-3p. Western blotting was used to detect the protein level of ACE2. Flow cytometry was used to observe the apoptosis of A549 cells in those groups. The data between groups were compared by t test. Results: In ARDS rat model, PO(2) value was significantly increased in ARDS+ pcDNA-GAS5 group than that in ARDS+ pcDNA group[(81.5±3.3) vs (57.5±5.1) mmHg, t=4.850, P<0.05], and PCO(2) value was significantly decreased in ARDS+ pcDNA-GAS5 group than that in ARDS+ pcDNA group[(50.6±1.9) vs (64.0±1.9) mmHg, t=5.940, P<0.05]. LncRNA GAS5 level in A549 cells of LPS group decreased significantly than that in control group (0.43±0.01 vs 1.01±0.01, t=0.242, P<0.05). Compared with LPS+ pcDNA group, ACE2 expression increased significantly in LPS+ pcDNA-GAS5 group (0.85±0.04 vs 0.34±0.02, t=1.800, P<0.05). Compared with LPS+ pcDNA-GAS5+ pre-NC group, ACE2 expression decreased significantly in LPS+ pcDNA-GAS5+ miR-200c-3p mimic group (0.62±0.01 vs 0.84±0.02, t=9.440, P<0.05). Compared with control group, the percentage of A549 cell apoptosis promoted significantly in LPS group (25.90±0.61 vs 7.90±0.22, t=0.257, P<0.05). Compared with LPS+ pcDNA group, the percentage of A549 cell apoptosis suppressed significantly in LPS+ pcDNA-GAS5 group (10.50±0.37 vs 26.37±0.45, t=1.760, P<0.05). Compared with LPS+ pcDNA-GAS5+ pre-NC group, the percentage of A549 apoptosis promoted significantly in LPS+ pcDNA-GAS5+ miR-200c-3p mimic group (19.07±0.56 vs 10.87±0.26, t=0.643, P<0.05). Conclusion: In ARDS, down-regulation of lncRNA GAS5 decreases ACE2 expression through increasing miR-200c-3p to promote the apoptosis of A549 cells, thus to promote the progression of ARDS.

[Analysis of characteristics and influencing factors of fine particulate matters and submicron particulate matters in printing shop]

Objective: To analyze the physical characteristics of fine particulate matters (PM(2.5)) and submicron particulate matters (PM(1)), and investigate the factors influencing the emission peak of printer particles. Methods: A 12-hour particle concentration monitoring for PM(2.5) and PM(1) was conducted in a printing shop on January 5(th), 2018. PM(2.5) in the air was analyzed after the monitoring process to figure out morphological characteristics and element composition of printer particles. Besides, experiments were carried out in an enclosed space to detect the number concentration peaks of PM(1) during every printing process. Influencing factors investigated in this study were printer types, toner coverages and interval time between different printing processes. Results: The 12-hour particles concentration monitoring showed that the number concentration of PM(1) and the mass concentration of PM(2.5) were 7.510×10(4) pt/cm(3) and 96.85 μg/m(3). The diameter of most PM(2.5) was less than 100 nm, with a fractal dimension of 2.591. Most PM(2.5) appeared as regular spheres with typical agglomeration phenomenon, while some were in rhabditiform or irregular shapes. Element analysis showed that PM(2.5) was mainly composed of C, O, Si, Ca, with less metallic element. The PM(1) emission peak values of three printers were 3.60×10(4), 3.43×10(4), 0.31×10(4) pt/cm(3), respectively and the difference was not statistically significant (χ(2)=5.42, P>0.05). When the page coverage rate was 0%, 2.5%, 5%, 10%, 20% and 50%, the PM(1) emission peak value of printer A was 6.74×10(4), 4.62×10(4), 3.82×10(4), 2.82×10(4), 1.00×10(4) and 1.08×10(4) pt/cm(3), and the difference was also not statistically significant (χ(2)=7.01, P>0.05). The natural logarithm of PM(1) emission peak value in printing work was associated with the resting time before printing and the change value of heating roller temperature (r value was 0.83 and 0.89, respectively, all P values<0.05). Conclusion: PM(2.5) and PM(1) in the printing shop stayed at a high level. Particles appeared as various shapes and element compositions were complex. The temperature change of heating roller was one of most important factors that lead to the increased number concentration peak of PM(1).

Serum Stem Cell Factor Level Predicts Decline in Kidney Function in Healthy Aging Adults

BACKGROUND AND OBJECTIVES

Stem cell factor (SCF), the ligand of the c-kit receptor, actively participates in the organ reconstruction and fibrosis associated with various diseases, including kidney disease. However, it remains unclear whether SCF plays a role in kidney aging.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

In the present study, we measured the serum SCF level, estimated glomerular filtration rate (eGFR), and other biological parameters in a Chinese Han group of 892 subjects, and explored the relationship between SCF level and renal function during aging; we sought to define novel biomarkers of kidney aging.

RESULTS

Multiple linear regression was used to select potential indicators of decline in renal function. Only age, SCF level, and 25% maximum expiratory flow (25% MEF) were significant predictors after redundancy analysis (|r| > 0.70 and P < 0.05). Multiple linear regression showed that the relationship among eGFR, SCF level, and age could be described as follows: eGFR = 154.486 - (0.846 × age) - (0.011 × SCF level).

CONCLUSIONS

We found no between-gender difference in the effect of SCF on kidney aging. In conclusion, the SCF level is an ideal biomarker of renal aging and may help to predict changes in eGFR during aging.

Green Synthesis of Porous Cocoon-like rGO for Enhanced Microwave-Absorbing Performances

A novel porous cocoon-like reduced graphene oxide (rGO) with high porosity and low density was fabricated by a simple and green reduction reaction using ascorbic acid as the reductant in combination with a freeze-drying process without annealing. The bulk density of porous cocoon-like rGO is only 28.49 mg/cm³, and the porosity reaches 94.57%. The reaction times have an important influence on the formation of porous cocoon-like rGO and the reduction degree of rGO. The porous cocoon-like rGO exhibits an excellent microwave-absorbing property with a low mass filling ratio of 7.0 wt %; its minimum reflection loss (RL) is -29.05 dB at 15.96 GHz with a sample thickness of 2.0 mm and the effective absorption bandwidth (RL < -10 dB) is 5.27 GHz. The microwave-absorbing property of porous cocoon-like rGO is much better than that of GO and other porous rGO. The in-depth analyses of the reduction degree, porosity, and microwave-absorbing performance illustrate that the microwave-absorbing performance of rGO is significantly related to the reduction degree and porosity. In addition, the synthetic route for porous cocoon-like rGO is simple, has low energy consumption, and is environmentally friendly. Our work demonstrates that the porous cocoon-like rGO is a promising lightweight microwave absorber with high performance.

[Imaging diagnosis of brucella spondylitis and tuberculous spondylitis]

Objective: To compare the characteristics of X-ray, CT and MRI of Brucella spondylitis and tuberculous spondylitis and its significance for differential diagnosis. Methods: A total of 10 cases of Brucella spondylitis and 20 cases of tuberculous spondylitis confirmed from the clinical, laboratory or pathological department were enrolled between January 2014 and August 2017 in the Fifth Affiliated Hospital of Sun Yat-sen University and the Third Affiliated Hospital of Southern Medical University. The CT, MRI findings were retrospectively analyzed to improve the differential diagnosis of these two diseases. Results: Of the 10 cases of Brucella spondylitis, 8 were located only in the lumbosacral vertebrae, 1 in the thoracic vertebrae only, 1 in the cervical and thoracic vertebrae, 8 with invasive bone destruction, and 8 with narrowed intervertebral space. In 9 cases of intervertebral disc destruction, 7 cases developed paravertebral abscesses, 3 cases had sclerotic edges, all cases had no vertebral body flattening, 5 cases invaded the accessory, 4 cases formed sequestrum, and 6 cases invaded the spinal canal. There were 3 cases showing invasion of surrounding muscles. In 20 cases of tuberculous spondylitis, 12 cases were located in the lumbosacral vertebrae, 6 cases in the thoracic vertebrae only, 1 involved the thoracic vertebrae and lumbosacral vertebrae, 1 involved the neck, chest, and lumbosacral vertebrae. Bone destruction of bone, 19 cases of intervertebral space narrowing, 20 cases of intervertebral disc destruction, 18 cases of paraspinal abscess formation, 10 cases of sclerotic edge formation, 6 cases of vertebral body flattened, 16 cases of invading attachment. There were 17 cases of sequestrum formation, 13 cases of invasion of the spinal canal, and 12 cases of violation of surrounding muscles. There were statistical differences between the two types of imaging signs such as the type of vertebral destruction and the presence or absence of sequestrum. Conclusion: The type of vertebral destruction and the presence or absence of imaging features such as sequestrumwill facilitate the differential diagnosis of Brucella spondylitis and tuberculous spondylitis.

[Clinical evaluation of socket shield technique in maxillary anterior region]

Objective: To evaluate the preliminary clinical outcome of socket shield technique in maxillary anterior region. Methods: Nine patients were treated with socket shield technique in Peking University School and Hospital of Stomatology from February 2012 to December 2015 were enrolled in this study. Ten implants were placed and restored immediately. After 12-48 months' follow-up (averaged 32 months), the peri-implant hard and soft tissue were clinically evaluated. Results: No implants were lost during the observation period, resulting a cumulate 32-month survival. The pink esthetic score (PES) was 13.5. Mesial and distal bone loss were 0.17 mm and 0.22 mm respectively. Conclusions: To achieve good esthetic results, socket shield technique may be an option for maxillary anterior region immediate implant placement.

Gd-EOB-DTPA DCE-MRI biomarkers in a rabbit model of liver fibrosis

The purpose of this study was to investigate the correlations between Gd-EOB-DTPA DCE-MRI biomarkers and histopathologic biomarkers of liver fibrosis progression in a rabbit model of liver fibrosis. Thirty-Six New Zealand white rabbits were randomly divided into control (n = 6) and liver fibrosis group (n = 30). Each rabbit in the liver fibrosis group received a weekly subcutaneous injection in the back comprising 50% carbon tetrachloride (CCl₄) in oily solution. Control rabbits received subcutaneous injections with the same amount of normal saline solution instead. MR imaging was performed in control and fibrotic rabbits were conducted by MRI at week 0 (n = 36). The fibrotic rabbits were performed MR imaging on 6 weeks, 9 weeks, and 12 weeks after modeling of fibrosis. Before each MRI, peripheral blood was collected, and several biochemical testes are performed. The thirty-four rabbits completed this study. They were then divided into three subgroups according to fibrotic stage: no fibrosis (F0, n = 12), mild fibrosis (F1+F2, n = 14), and advanced fibrosis (F3+F4, n = 8). DCE-MRI measurements show increasing K^trans and V_e while decreasing iACU90 with increasing fibrosis stage. The significant correlations were observed between mean K^trans, V_e, iACU90 and percentage of the animal with mild liver fibrosis. For blood biomarkers, there were significant differences between F0 and F1+F2, and between F0 and F3+F4 in the serum levels of ALT (all P < 0.05), and TB (F0 vs. F1+F2, P = 0.004), while no differences were found between F1+F2 group and F3+F4 group (all P > 0.05). There were significant differences between F0 and F1+F2 (P = 0.02). Gd-EOB-DTPA DCE-MRI is a promising method for the noninvasive diagnosis and staging of liver fibrosis. Future studies to evaluate the effectiveness of these techniques in patients with liver fibrosis are warranted.