[Rapid serotyping of Salmonella based on matrix assisted laser desorption ionization-time of flight mass spectrometry].

Objective: To establish a matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) assay for the identification of common Salmonella serotypes and provide etiology evidence for the early precise treatment of salmonellosis. Methods: A total of 500 strains were collected from different regions and sources and five predominant Salmonella serotypes (Salmonella Typhi, Salmonella Paratyphi A, Salmonella Typhimurium, Salmonella Enteritidis, and Salmonella Indiana) of each strain was identified by agglutination test and whole-genome sequencing. The protein complex of the strains was extracted by using optimized pretreatment method to establish the fingerprint database of peptides for each Salmonella serotype. The new serotyping assays were established by using different modules based on the mass spectra database. Additional 155 strains with specified serotypes and variant sources were used to test and evaluate the accuracy of the new typing assays. Results: Five MALDI-TOF MS databases were established, and two new serotyping assays were established via peptide fingerprint mapping/matching and machine learning of the neuronal convolutional network respectively based on the databases. The results showed that the fingerprint matching approach could quickly identify five common Salmonella serotypes in clinical practice compared with the machine learning method, the accuracy of fingerprint matching assay to identify five Salmonella serotypes reached 100.00% and the serotyping can be conducted within a short time (15-20 minutes) and had a good reproducibility, while the machine learning method could not completely identify these serotypes. Moreover the sensitivity and specificity of fingerprint matching assay were all 100.00% respectively, while they were only 82.23% and 95.81% for machine learning method. Conclusion: The established Salmonella serotyping assay based on MALDI-TOF MS in this study can easily, rapidly and accurately identify different serotypes of Salmonella.

[Establishment of multi-sector collaborative mechanism and surveillance network for Salmonella infection outbreak response and control].

Salmonellosis is one of the common food-borne diseases, local and cross-region outbreaks are not rare. The risk of cross-border transmission of Salmonella is increasing with the high frequency of global economic trades. The recently occurred multi-country outbreaks of Salmonella Typhimurium infection associated with chocolate products have highlighted the importance of improving capability of surveillance and warning of foodborne-disease, especially salmonellosis, in China. It is essential to strengthen the collaboration among clinical medicine, disease control and food safety institutions, improve the capability of whole-genome sequencing of Salmonella for the disease surveillance and tracing, and facilitate the information sharing and collaboration among the food safety related sectors for the timely detection, prevention and control of outbreaks of Salmonella infection in China.

Pyroelectric effect mediated infrared photoresponse in Bi2Te3/Pb(Mg1/3Nb2/3)O3-PbTiO3 optothermal ferroelectric field-effect transistors.

The responses of material properties to multi-field stimulation are often exploited to construct new types of multi-functional devices. Here, we demonstrate electrical, optical and thermal modulation of the electronic properties of optothermal ferroelectric field-effect transistors (FeFETs) which are fabricated by growing Bi2Te3 films on (111)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO 3 (PMN-PT) ferroelectric single-crystal substrates. Using the electric field to switch the polarization direction of PMN-PT, the carrier density and resistance of Bi2Te3 films are in situ, reversibly, and nonvolatilely modulated via the ferroelectric field effect. Moreover, through infrared light illumination on the bottom of PMN-PT substrates, the resistance of Bi2Te3 films in two polarization states could be further modulated, which is ascribed to the decreased polarization intensity at higher temperature due to the pyroelectric effect. Taking advantage of these two effects, the Bi2Te3/PMN-PT optothermal FeFETs exhibit multiple responses to optical and electric field stimulation at room temperature. Our work provides a strategy to design optoelectronic devices with both photodetector and memory functionalities.

[Clinical features of 141 fatal cases of coronavirus disease in Jinyintan Hospital in Wuhan, China].

Objective: To describe the epidemiological characteristics and clinical features of patients with fatal coronavirus disease (COVID-19), in order to provide evidence for clinical diagnosis and treatment. Methods: In this retrospective study, we analyzed data on 141 fatal cases of confirmed COVID-19 that occurred among patients in Jinyintan Hospital in Wuhan, China, from January 20 to March 6, 2020. We analyzed their epidemiological characteristics, clinical and radiological features, laboratory results, and treatment. Results: Of the 141 patients (49 females, 92 males), the median age was 77 years (range: 24-92 years). The most likely source of exposure included the Huanan seafood market (n=3, 2%), family members (n=6, 4%), and hospital-acquired infection (n=8, 6%). The remaining 116 patients (72%) had no known source of exposure. Of the patients, 101 (72%) had chronic diseases. The most common comorbidities were hypertension, diabetes and coronary heart disease. The most common clinical manifestations were fever (n=121, 85%), dry cough (n=77, 54%), shortness of breath (n=23, 16%), and chest pain (n=15, 10%). Less common clinical manifestations included fatigue (n=7, 4%), headache (n=3, 2%), disorders of consciousness (n=2, 1%), diarrhea (n=2, 1%) and lumbago (n=1, 0.7%). In terms of laboratory tests, the absolute value of lymphocytes in most patients was reduced (n=132, 94%), but C-reactive protein (n=141, 100%), procalcitonin(n=121, 89%), serum amyloid (n=140, 99%) were significantly increased. The most common findings on imaging of the lungs were bilateral multiple mottling and ground-glass opacity (n=101, 72%), mainly in the lower lobes (n=15, 10%), with lesions being more common on the right. Other imaging findings included diffuse consolidation (n=4, 3%), ground-glass opacity and consolidation (n=20, 14%), and pneumothorax (n=1, 0.7%). All patients were treated with antibiotics and antiviral drugs. Other treatments included immunoglobulin (n=49, 35%), corticosteroids (n=45, 32%), continuous renal replacement therapy (n=24, 17%), and extracorporeal membrane oxygenation (n=12, 9%). All patients were treated with oxygen therapy. The mode of administration included invasive mechanical ventilation (n=61, 43%), noninvasive mechanical ventilation (n=65, 46%), and nasal catheter oxygen inhalation (n=15, 11%). The direct causes of death were acute respiratory distress syndrome (n=90, 64%), multiple organ failure (n=24, 17%), sudden cardiac arrest (n=11, 8%), viral myocarditis (n=8, 5%), acute myocardial infarction (n=4, 3%), cerebrovascular accident (n=3, 2%), and acute gastrointestinal bleeding (n=1, 0.7%). Conclusions: Risk factors for death due to COVID-19 included older age, male sex, and the presence of comorbidities. The most common direct causes of death were acute respiratory distress syndrome, multiple organ failure, sudden cardiac arrest, and viral myocarditis.

[Epidemiological characteristics and molecular typing of typhoid and paratyphoid in China, 2009-2013].

Objective: To understand the epidemiological and molecular characteristics of typhoid and paratyphoid in China from 2009 to 2013, and provide evidence for the prevention and control of typhoid and paratyphoid, the development and improvement of surveillance strategies. Methods: Epidemiological analysis was conducted on the incidence data of typhoid and paratyphoid, and related public health emergencies in China during 2009-2013. Pathogen isolation and culture, serologic test were conducted for the typhoid and paratyphoid cases from 13 national surveillance sites. The isolates were subjected to antimicrobial susceptibility testing. Pulsed-field gel electrophoresis (PFGE) was performed for the molecular typing of these isolates. Results: The average incidence of typhoid and paratyphoid in China during this period was 1.03/100 000. The reported case number and incidence decreased with year. The provinces reporting high case numbers were Yunnan, Guizhou, Guangxi, Hunan, Zhejiang, Guangdong and Xinjiang. The incidence of age group 0-4 years was highest. The proportion of farmers and children outside child care settings showed an increasing tendency over time. The annual incidence peak was during July-August. Twenty five outbreaks occurred during 2009-2013. The results of pathogen isolation and culture showed that the positive rate was 3.00% (940/31 322), among the positive isolates, the proportion of Salmonella paratyphi A accounted for higher proportion (68.19%, 641/940) compared with Salmonella typhi (31.60%, 297/940). The drug resistances of Salmonella typhi and Salmonella paratyphi varied, but their resistances to nalidixic acid were highest (50.22% and 85.33%) respectively. A certain amount of Salmonella typhi isolates showed the resistance to the 3rd generation cephalosporins. PFGE analysis showed divergent patterns of Salmonella typhi compared with limited patterns of Salmonella paratyphi A. Conclusion: The epidemic level of typhoid and paratyphoid in China was relatively low, but the outbreak occurred occasionally. It is necessary to enhance the laboratory-based surveillance, particularly the capability of etiological diagnosis, outbreak investigation, response and antibiotic resistance monitoring, and conduct risk factor investigation in provinces with high incidences in recent years.

[Comparison of colonization ability of O1 and O139 Vibrio cholerae strains on soft-shelled turtle's surface].

Objective: To study the preferred colonization sites of O1 Vibrio cholerae (V.cholerae) and the colonization ability difference for O1 and O139 V. cholerae on soft-shelled turtle's surface. Methods: 8 O1 and O139 V. cholerae strains were obtained from branch of diarrheal diseases, Chinese center for disease control and prevention. 63 soft-shelled turtles weighing 150 g and 9 cm in length (diameter of calipash) were selected for use in the study. The preferred colonization sites and proliferation trend were studied by using bioluminescent imaging method. The colonization factors for O1 V. cholerae strains were studied by constructing colonization gene mutant strains (VC1897dmshA, VC1897dgbpA and VC1897dtcpA), performing competition colonization assays and analyzing the competitive indexes. After pairing off O1 and O139 strains respectively to perform 16 competition groups, the colonization difference of these two strains were studied by competition colonization assays. Results: The colonization sites by V. cholerae on soft-shelled turtles surfaces was clustered. More V. cholerae strains colonized on turtle's calipash and carapace on dorsal side and less strain colonized on ventral side. The competition colonization assays showed that colonization ability of O1 serogroup mshA mutant strains were 7.26 times lower than VC1897dlacZ. Besides, the CI value (O139/O1) of 11 out of the 16 competition groups were greater than 2 (between 2.07 and 59.84). Two groups showed values of 1.43 and 0.93 respectively and 3 groups lower than 0.7. Conclusion: The preferred colonization sites for O1 V. cholerae strains on body surface were observed.MSHA was one of the main colonization factors for its colonization. Our study suggested that in general, O139 V. cholerae strains have stronger colonization ability than O1 strains. Besides, strains isolated from soft-shelled turtles tend to have stronger colonization ability than strains isolated from patients.

[Spatial and temporal clustering characteristics of typhoid and paratyphoid fever and its change pattern in 3 provinces in southwestern China, 2001-2012].

Objective: To analyze the spatial and temporal clustering characteristics of typhoid and paratyphoid fever and its change pattern in Yunnan, Guizhou and Guangxi provinces in southwestern China in recent years. Methods: The incidence data of typhoid and paratyphoid fever cases at county level in 3 provinces during 2001-2012 were collected from China Information System for Diseases Control and Prevention and analyzed by the methods of descriptive epidemiology and geographic informatics. And the map showing the spatial and temporal clustering characters of typhoid and paratyphoid fever cases in three provinces was drawn. SaTScan statistics was used to identify the typhoid and paratyphoid fever clustering areas of three provinces in each year from 2001 to 2012. Results: During the study period, the reported cases of typhoid and paratyphoid fever declined with year. The reported incidence decreased from 30.15 per 100 000 in 2001 to 10.83 per 100 000 in 2006(annual incidence 21.12 per 100 000); while during 2007-2012, the incidence became stable, ranging from 4.75 per 100 000 to 6.83 per 100 000 (annual incidence 5.73 per 100 000). The seasonal variation of the incidence was consistent in three provinces, with majority of cases occurred in summer and autumn. The spatial and temporal clustering of typhoid and paratyphoid fever was demonstrated by the incidence map. Most high-incidence counties were located in a zonal area extending from Yuxi of Yunnan to Guiyang of Guizhou, but were concentrated in Guilin in Guangxi. Temporal and spatial scan statistics identified the positional shifting of class Ⅰ clustering area from Guizhou to Yunnan. Class Ⅰ clustering area was located around the central and western areas (Zunyi and Anshun) of Guizhou during 2001-2003, and moved to the central area of Yunnan during 2004-2012. Conclusion: Spatial and temporal clustering of typhoid and paratyphoid fever existed in the endemic areas of southwestern China, and the clustering area covered a zone connecting the central areas of Guizhou and Yunnan. From 2004 to 2012, the most important clustering area shifted from Guizhou to Yunnan. Findings from this study provided evidence for the identifying key areas for typhoid and paratyphoid fever control and prevention and allocate health resources.

[An outbreak of paratyphoid fever in a county of Yunnan province, 2010-2011].

Objective: To identify the source and to comment on control program regarding an outbreak of paratyphoid A fever in a county, through field studies. Methods: Descriptive epidemiological methods were adopted to describe the epidemiological characteristics of the outbreak, which occurred in Yuanjiang county, Yunan province between 2010-2011, China. Case-control study with environmental investigation was performed to identify related risk factors and pathogens while isolation and susceptibility on the suspected pathogens were conducted. Subsequently, intervention and preventive measures were taken for the control of the outbreak. Results: A total of 600 cases were diagnosed and reported as paratyphoid fever A which spread over the whole Yuanjiang county, including 10 townships with different incidence rates. The disease was spatially clustered and the prevalence rates in these townships decreased with increasing distances from the polluted fields. Data from the case-control study discovered that consumption of raw vegetables was the main risk factor associated with this outbreak of paratyphoid fever (OR=65.3, P<0.001). Management of patients did not meet the requirements while feces and urine of the outpatients polluted the wastewater system in the city. Salmonella paratyphi A isolates were identified from the improperly disinfected wastewaters in hospitals and city systems, respectively. After the measures as prohibiting the planting of vegetables in contaminated fields and disinfection of hospital wastewater were taken, the outbreak subsided. Conclusions: Urban and hospital wastewater used for vegetables irrigation together with the tradition of eating uncooked vegetables seemed responsible for the outbreak of this paratyphoid fever. Intervention programs carried by the local government played a key role in controlling this large outbreak.

Inguinal hernia repair outcomes that utilized the modified Kugel patch without the optional onlay patch: a case series of 163 consecutive patients.

PURPOSE: The purpose of this study was to evaluate the efficacy and safety of the anterior Kugel herniorrhaphy approach when the onlay patch is omitted. METHODS: The study population comprised patients who underwent anterior Kugel herniorrhaphy without the onlay patch from 1 May 2009, to 31 June 2012. The onlay patch was omitted if the posterior wall defect did not exceed the inner Posiflex(®) ring diameter. After reviewing the clinical follow-up records and conducting telephone interviews, the postoperative results were recorded and analyzed. RESULTS: A total of 163 patients underwent 175 hernia repairs. One patient developed recurrence after undergoing our herniorrhaphy method. The most common postoperative complaints were mild soreness, indescribable discomfort, and foreign body sensations (11 patients). The mean operative time and hospital stay were 67 min and 2 days, respectively. More serious complications included one scrotal hematoma, one hydrocele, and one wound infection that resulted in epididymitis. CONCLUSIONS: The onlay patch can be omitted with low recurrence and complication rates if the posterior wall defects do not exceed the inner Posiflex(®) ring diameter.

MICA-STR, HLA-B haplotypic diversity and linkage disequilibrium in the Hunan Han population of southern China.

Major histocompatibility complex (MHC) class I chain-related gene A (MICA) is located 46 kb centromeric to HLA-B and encodes a stress-inducible protein. MICA allelic variation is thought to be associated with disease susceptibility and immune response to transplants. This study was aimed to investigate the haplotypic diversity and linkage disequilibrium between human leukocyte antigen (HLA)-B and (GCT)(n) short tandem repeat in exon 5 of MICA gene (MICA-STR) in a southern Chinese Han population. Fifty-eight randomly selected nuclear families with 183 members including 85 unrelated parental samples were collected in Hunan province, southern China. HLA-B generic typing was performed by polymerase chain reaction-sequence-specific priming (PCR-SSP), and samples showing novel HLA-B-MICA-STR linkage were further typed for HLA-B allelic variation by high-resolution PCR-SSP. MICA-STR allelic variation and MICA gene deletion (MICA*Del) were detected by fluorescent PCR-size sequencing and PCR-SSP. Haplotype was determined through family segregation analysis. Statistical analysis was applied to the data of the 85 unrelated parental samples. Nineteen HLA-B specificities and seven MICA-STR allelic variants were observed in 85 unrelated parental samples, the most predominant of which were HLA-B*46, -B60, -B*13, and -B*15, and MICA*A5, MICA*A5.1 and MICA*A4, respectively. Genotype distributions of HLA-B, MICA-STR loci were consistent with Hardy-Weinberg proportions. The HLA-B-MICA-STR haplotypic phases of all 85 unrelated parental samples were unambiguously assigned, which contained 30 kinds of HLA-B, MICA-STR haplotypic combinations, nine of them have not been reported in the literature. Significant positive linkage disequilibria between certain HLA-B and MICA-STR alleles, including HLA-B*13 and MICA*A4, HLA-B*38 and MICA*A9, HLA-B*58 and MICA*A9, HLA-B*46 and MICA*A5, HLA-B*51 and MICA*A6, HLA-B*52 and MICA*A6, and HLA-B60 and MICA*A5.1, were observed. HLA-B*48 was linked to MICA*A5, MICA*A5.1 and MICA*Del. HLA-B*5801-MICA*A10 linkage was found in a family. Our data indicated a high degree of haplotypic diversity and strong linkage disequilibrium between MICA-STR and HLA-B in a southern Chinese Han population, the data will inform future studies on anthropology, donor-recipient HLA matching in clinical transplantation and HLA-linked disease association.

TAME-esterase activity during a prolonged attack of asthma.

We measured serum N-alpha-tosyl-L-arginine methyl ester (TAME)-esterase activity in a group of patients suffering from a prolonged attack of asthma. Measurements were made pre and post salbutamol nebulization. Our results showed that TAME-esterase activity did not change significantly pre or post nebulization. Based on our experimental data, we concluded that increase serum TAME-esterase activity is a biochemical substance associated with the early asthmatic response but not with prolonged attack of asthma.

Tosyl arginine methyl ester induces bronchoconstriction in rabbit bronchial tissues in vitro: a possible new mediator in asthma.

Tosyl arginine methyl ester induced bronchoconstriction in rabbit bronchial rings mounted in vitro with a calculated EC50 of 5.6 x 10(-5) M as compared with acetylcholine which induced sustainable constriction with an EC50 of 2.5 x 10(-6) M. Tosyl arginine methyl ester, however, had definite bronchoconstricting properties though less potent than acetylcholine. We concluded that our data support the hypothesis that tosyl arginine methyl ester could be a possible biochemical mediator of airway contraction.

[Renal pelvic tumor associated with contralateral renal cyst--a case report].

A 74-year-old female presented with a two years history of malaise, weakness and intermittent gross hematuria. Two years earlier, left renal cyst had been diagnosed by excretory urography, abdominal sonography and computed-tomography. Initially she was treated conservatively with oral antibiotics, however medical management had not been successful in improving her condition. Finally she was transfer to our ward for further evaluation and treatment. Cystoscopic examination demonstrated no abnormality, except for bloody urine efflux from the right ureteric orifice. Right retrograde pyelograms confirmed a solitary filling defect in the upper calyx of right kidney. Because of immediate concern for right renal pelvic tumor and contralateral renal cyst, a midline transperitoneal exploration was made. The right nephroureterectomy with cuff of bladder was removed and left unroofing of cyst was carried out. Convalescence was uneventful. The pathologic examination revealed moderately differentiated transitional cell carcinoma of right kidney with a simple renal cyst of left kidney. We suggest that cases with a clinical diagnosis of renal cyst based on the presence of gross hematuria, a normals excretory urogram and computed tomogram, generally require further evaluation especially by cystoscope and retrograde pyelogram to determine the source of bleeding.

Thiol peroxyl radical formation from the reaction of cysteine thiyl radical with molecular oxygen: an ESR investigation.

Using Electron Spin Resonance (ESR) spectroscopy, we have identified the cysteine thiol peroxyl radical (CysSOO.) at low temperatures in two aqueous glasses. This radical shows a typical peroxyl radical ESR spectrum, but unlike carbon-based peroxyl radicals has a violet color (lambda max = 540 nm) and forms a new radical showing a singlet ESR spectrum when photobleached with visible light. The cysteine peroxyl radical reacts to form the cysteine sulfinyl radical (CysSO.) in the glass which allows warming to 165K. 17O isotopic substitution studies indicate dissolved molecular oxygen is the source of oxygen in CysSOO.. Anisotropic g-values and the parallel anisotropic 17O hyperfine couplings for this radical are reported.