Objective To study the effect of different strains of mice(KM and ICR)immunized with rabies vaccine on thedetection of titer.Methods The rabies vaccine and the national standard for the efficacy verification of rabies vaccine forhuman use(referred to as national standard)were diluted with PBS at the ratios of 1∶25,1∶125,1∶625 and 1∶3 125,and KM and ICR mice with half male and half female were immunized intraperitoneally respectively.Sixteen mice of each strain wereimmunized with 0.5 m L/mouse at each dilution.The immunization was strengthened once every one week at the same dose androute.The mice in each group were weighed 0,7 and 14 d after the initial immunization.After 14 d of the initial immunization,the mice were subjected to intracranial attack with rabies virus(RABV)CVS2(5-100 LD_(50)),0.03 m L/mouse.The numberof mice with death and typical rabies brain symptoms 5 d after the attack was counted.According to the national standard ED_(50),the relative efficacy was calculated by Reed-Muench method.Results The body mass of the two strains of miceshowed an increasing trend during the immunization stage,and the body mass of KM mice increased faster than that of ICRmice.The lgED_(50) values of the national standard in KM mice were all within the expected range of 2.10-2.75,while thevalues in ICR mice were higher than the range.The titers of rabies vaccine in KM mice were all significantly lower than thosein ICR mice(t = 2.887-6.619,each P < 0.05).Conclusion Mouse strains can significantly affect the results of rabies vaccine titer determination,and different standards should be adopted for different strains of mice to ensure the accuracy of vaccine detection results.

Pictet-Spenglerases (P-Sases) catalyze the Pictet-Spengler (P-S) reactions and exhibit high stereoselectivity and regioselectivity under mild conditions. The typical P-S reaction refers to the condensation and recyclization of β-arylethylamine with aldehyde or ketone under acidic conditions to form tetrahydroisoquinoline and β-carboline alkaloid derivatives. The related enzymatic products of P-Sases are the backbones of various bioactive compounds, including clinical drugs: morphine, noscapine, quinine, berberine, ajmaline, morphine. Furthermore, the activity of P-Sases in stereoselective and regioselective catalysis is also valuable for chemoenzymatic synthesis. Therefore, this review summarizes the research progress in the discovery, functional identification, biological characteristics and catalytic applications of P-Sases, which provide the useful theoretical reference in future P-Sases research and development.
Alkaloids/chemistry* ; Catalysis ; Enzymes/metabolism* ; Research/trends* ; Tetrahydroisoquinolines/chemistry*

Objective: To analyze the molecular characteristics of Listeria monocytogenes strains from ready-to eat food in China. Methods: A total of 239 Listeria monocytogenes strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates. Results: All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs. Conclusion Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.

With the outbreak of COVID-19, non-stop working medical staff need to wear protective equipment for a long time, which could easily cause device-related pressure injuries to nose, cheek, forehead or the back of auricle, and might even cause facial skin swelling and ulceration. The above problems reduce work efficiency and increase the infection risk for healthcare people. This article introduces the concept of device-related pressure injuries and summarizes the progress of the treatment for device-related pressure injuries at home and abroad in recent years, aiming at providing guidance for frontline medical staff to prevent device-related pressure injuries.

Foodborne Campylobacter is recognized as the leading causes of the bacterial diarrheal illness in both developing and developed countries. C. jejuni and C. coli caused 95% of the human campylobacterisosis. Bacteria culture has been recognized as the "Gold standard" for the diagnosis of the Campylobacter infection. The National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention coordinated the experienced researchers from China National Center for Food Safety Risk Assessment and other local Centers for Disease Control and Prevention to write up the standards for entitled Isolation and Identification of Campylobacter jejuni and Campylobacter coli (T/CPMA 006-2019). The standard is drafted with principles of emphasizing the scientific, normative, applicability and feasible nature. This group standard recommended the procedures and steps for the isolation and identification of C. jejuni and C.coli from variant samples. The standard aims to improve the capacity for Campylobacter identification in China.

Objective To investigate the association between RNF213 rs6565666 polymorphisms and intracranial cystic aneurysms in patients from Guangdong province. Methods Two hundred and fifty patients with intracranial cystic aneurysms, admitted to and conformed by digital substraction angiography (DSA) in our hospital from February 2016 to October 2018, were selected as experimental group; and 250 patients without intracranial aneurysms conformed by DSA, CT angiography or magnetic resonance angiography at the same time period were used as control group. The genotypes of rs6565666 locus of RNF213 gene were detected by polymerase chain reaction-ligase detection reaction (PCR-LDR). Results As compared with those in the control group, percentages of AG and AA genotypes were significantly higher and percentage of GG genotype was statistically higher at rs6565666 locus of patients from the experimental group (P<0.05). The proportion of allele A at rs6565666 locus in the experimental group was statistically higher as compared with that in the control group (P<0.05). In the experimental group, 112 patients had ruptured aneurysms and 138 patients did not have ruptured aneurysms; there was no statistically significant difference in the genotype distribution of rs6565666 between the ruptured group and the non-ruptured group (P>0.05). Conclusion RNF213 gene rs6565666 polymorphism is associated with intracranial cystic aneurysms in patients from Guangdong province.

Objective: Tests were carried out for obtaining contamination level and antimicrobial resistance of Salmonella on broiler carcasses after chilling in four poultry slaughterhouses in Henan. Methods: Totally, two hundred sixty nine broiler carcasses after chilling were collected in four slaughterhouses with the daily slaughter amount around 15 000 to 50 000. For qualitative analysis of Salmonella EFSA method was used and for quantitative analysis of Salmonella modified Rappaport-Vassiliadis most probable number (MSRV-MPN) method was used. All of the isolates were subjected to antimicrobial susceptibility testing of 8 antibiotics by minimum inhibitory concentration (MIC). Results: Overall, 48.7% (131/269) of the broiler carcasses after chilling were contaminated by Salmonella, and the average of contamination level is 1.32 most probable number MPN/g. Eight serotypes were detected. The dominant serotype is Salmonella enteritidis (93, 71.0%) followed by Salmonella Indiana (21, 16.0%). Only 2 (1.5%) Salmonella enteritidis strains were sensitive to all the tested antibiotics and the remaining 129 isolates were resistant to at least one kind of eight class antibiotics. Among them, resistant to NAL was the common (104, 79.4%) and 51 (38.9%) Salmonella isolates were multidrug-resistant. Conclusion The contamination rate and multiple antimicrobial resistant of Salmonella on broiler carcasses after chilling from slaughterhouses was very serious, while the isolates contained various serotypes.

Objective: To determine the prevalence and antimicrobial susceptibility of Salmonella isolated from broiler production process in 4 provinces of China. Methods: Using convenience sampling method, 238 sample sites from broiler whole production process were chosen in Henan, Jiangsu, Heilongjiang and Shandong provinces in 2012. A total of 11 592 samples were collected and detected to analyze prevalence baseline, including 2 090 samples from breeding chicken farms and hatcheries, 1 421 samples from broiler farms, 5 610 samples from slaughterhouses and 2 471 samples from distribution and retail stores. All Salmonella strains were isolated through selective enrichment, and were serotyped according to Kauffmann-White scheme. The antimicrobial susceptibilities of selected Salmonella strains were determined by the broth microdilution method and fourteen antimicrobial agents were examined. Results: During incubation course, the average prevalence of Salmonella was 5.5% in feces of breeding hens, feces of chicks, and hatching eggs, 123 Salmonella strains were isolated. During cultivation course, the prevalence of Salmonella was 8.0% in feces from broiler farms, soil, feed, and workers, 114 Salmonella strains were isolated. During slaughter course, the prevalence of Salmonella was 24.9% in swabs pre-slaughter, dressed broiler carcasses, pre-cooled broiler carcasses, water from precooling pool, cutter and chipping boards, frozen chicken portions, and workers, 1 438 Salmonella strains were isolated. During distribution and sale course, the prevalence of Salmonella was 20.9% in transport carts, frozen chicken portions, retail chicken portions and workers, 551 Salmonella strains were isolated. The dominant Salmonella serotypes were Salmonella Enteritidis (n=1 229) and Salmonella Indiana (n=621). Among 1 231 examined strains, 97.2% Salmonella isolates were resistant to at least one antimicrobial, 69.9% Salmonella strains were multi-drug resistant isolates. Conclusion Our findings indicated that Salmonella contamination was common and serious in commercial broiler whole production process in China, especially in the course of defeathering, precooling and selling. The environment of broiler farm is the important source of Salmonella contamination. Additionally, antibiotic resistance of Salmonella was serious for common antimicrobials and multi-drug resistant strains existed widespread, which can pose potential risk on public health and clinical therapy.

Foodborne disease is one of the most important public health issues worldwide. China faces various and unprecedented challenges in all aspects of the food chain. Data from laboratory-based foodborne disease surveillance systems from 2013 to 2016, as well as different regions and ages, can be found along with differences in the patterns of pathogens detected with diverse characteristics. Vibrio parahaemolyticus has been the leading cause of infectious diarrhea in China, especially among adults in coastal regions. Salmonella has been a serious and widely distributed pathogen responsible for substantial socioeconomic burden. Shigella was mostly identified in Northwest China and the inland province (Henan) with less-developed regions among children under 5 years. Data from foodborne disease outbreak reporting system from 2011 to 2016 showed that poisonous animals and plant factors responsible for most deaths were poisonous mushrooms (54.7%) in remote districts in southwest regions. The biological hazard that caused most cases reported (42.3%) was attributed to V. parahaemolyticus, the leading cause of foodborne outbreaks. In this review, we summarize the recent monitoring approach to foodborne diseases in China and compare the results with those in developed countries.
Bacteria ; classification ; isolation & purification ; China ; epidemiology ; Disease Outbreaks ; Food Microbiology ; Foodborne Diseases ; epidemiology ; microbiology ; Forecasting ; Humans ; Laboratories ; Mushroom Poisoning ; epidemiology ; Population Surveillance ; Public Health

Objective To explore the effect of Willis circle variation and hemodynamic forces alteration arised from vascular structural abnormity on intracranial aneurysm (IA) rupture using 3D-digital subtraction angiography (DSA) and transcranial color Doppler (TCCD) detection.Methods Two hundred and twenty-three patients with IA,admitted to and conformed by DSA in our hospital from November 2010 to November 2011,were divided into ruptured IA group (n=182) and un-ruptured IA group (n=41).The 3D-DSA was applied in all patients to carefully evaluate the aneurysm sizes,locations,and morphous features,and to confirm the presence of A1 dominance and Willis circle variation.Moreover,aneurysmal neck area,diameter of parent artery,angle between A2 segments of bilateral anterior cerebral artery,angle between aneurysmal longitudinal axis and parent artery,aortic diameter (AD) and aspect ratio (AR) were measured with assistance of 3D-DSA images.Besides,TCCD was applied to all patients,and the hemodynamic parameters were recorded to calculate wall shear stress (WSS) and mechanical stretch.The risk factors of IA rupture were analyzed by receiver operating characteristic (ROC) curve and multivariate Logistic regression with emphasis on Willis circle variation and hemodynamic forces alteration.Results Whether it was in ruptured IA group or in un-ruptured IA group,the incidence rate of variation of anterior Willis circle was higher than that of variation of posterior Willis circle.A1 dominance on the left side was the most common asymmetry.As compared with those in un-ruptured IA group,statistically elder age,smaller AD,larger angle between aneurysmal longitudinal axis and parent artery,decreased WSS and increased mechanical stretch in the ruptured IA group were noted (P＜0.05).ROC curve indicated that angle between aneurysmal longitudinal axis and parent artery,AD,WSS and mechanical stretch could be used to evaluate IA rupture (area under the curve:0.606、0.618、0.396、0.637).Age (OR=8.618,95％CI:2.866-25.917,P=0.000),hypertension (grade Ⅲ OR=16.320,95％CI:1.628-163.556,P=0.018),angle between aneurysmal longitudinal axis and parent artery (OR=3.053,95％CI:1.131-8.242,P=0.028),AD (OR=5.638,95％CI:1.507-20.251,P=0.008) and mechanical stretch (OR=4.230,95％CI:1.554-11.516,P=0.000) were risk factors of IA rupture.A1 dominance (OR=0.242,95％CI:0.074-0.785,P=0.018),small aneurysms (2-5 mm,OR=0.207,95％CI:0.054-0.788,P=0.002) and WSS (OR=0.021,95％CI:0.060-0.672,P=0.009) were identified as protective factors.Conclusions Willis circle variation exists in IA patients.Age,hypertension (grade ⅢD,angle between aneurysmal longitudinal axis and parent artery,AD and mechanical stretch are risk factors of IA rupture,while A1 dominance,small aneurysm (2-5 mm) and WSS are identified as protective factors.Accurate assessment of these factors is of great clinical significance for the prevention and treatment of IA in the future.