Objective:To understand the contamination risk, drug resistance and virulence characteristics of cooked food pathogens in Tianjin.Methods:Pathogenic bacteria were isolated and identified in cooked food sold in Tianjin from 2019 to 2021, drug susceptibility test and whole genome sequencing were conducted for the isolates, and multilocus sequence typing, drug resistance gene, phenotype and virulence gene were analyzed for the data.Results:Ten pathogenic bacteria were isolated from 245 cooked food samples collected. The ST types of 7 Salmonella strains were ST40, ST198, ST14, ST13 and ST155. The two strains of Vibrio parahaemolyticus were ST647 and ST2622 respectively. One strain of Cronobacter sakazakii was ST8 type. All the 6 isolates were drug-resistant, and 3 of them were multidrug-resistant (MDR). A total of 63 drug-resistant genes were predicted in 10 isolates. Two Salmonella strains were ampicillin-chloramphenicol-streptomycin-sulfamethoxazole-tetracycline resistant (MDR-ACSSuT), and both Salmonella strains carried gyrA double mutations (S83F, D87N) and parC mutations (S80I). Vibrio parahaemolyticus mainly carries blaCARB and tet (35) genes, while Cronobacter sakazakii carries only one resistance gene blaCSA-1. A total of 163 virulence genes were predicted from 10 isolates. Conclusions:In this study, pathogenic bacteria are repeatedly detected in quail eggs, warning that other eggs besides chicken eggs should also pay special attention to the risk of contamination. The isolates in this study are all of the prevalent ST type with widespread drug resistance, and MDR-ACSSuT strains should be paid attention to. The key role of gyrA double mutation (S83F, D87N) and parC mutation (S80I) in the development of quinolone resistance should not be ignored. T3SS (typeⅢ secretory system) and T6SS (typeⅥ secretory system) are important virulence gene clusters of Salmonella and Vibrio parahemolyticus.

Objective: To analyze the epidemiological characteristics and pathogen types of viral diarrhea in children under 5 years of age in Shandong province, and provide reference for the prevention and control of viral diarrhea. Methods: A total of 1 017 fecal samples were collected from all children aged 5 years and younger with diarrhea who were admitted to the sentinel hospital of Shandong province from 2012 to 2017 within 3 days. Rotavirus antigen was detected by using an ELISA method . Rotavirus G/P typing was performed by RT-PCR; Norovirus (GI and GII), Sapovirus, and Astrovirus were detected by multiplex RT-PCR, and adenovirus was detected by PCR. Results: In the 1 017 fecal specimens, the overall positive rate was 51.62% (525/1017), and viral nucleic acids were detected in at least 421 samples, and mixed virus infection was found in 104 sampes. The mixed infection accounted for 10.23% (104/1017) of all infections. The positive detection rates of Rotavirus, Calicivirus, Adenovirus and Astrovirus were 34.22% (348/1017), 16.91% (172/1017), 2.56% (26/1017), and 9.64% (98/1017)). The total detection rate of diarrhea virus and the detection rate of Rotavirus were the highest at 12 to 17 months of age, which was 51.72% (105/203) and 20.20% (41/203), respectively. The positive rate of diarrhea in children aged 2 years and younger was 49.36% (502/1017), which was much higher than the positive rate of diarrhea in children over 2 years old (2.26% (23/1017)). The peak of viral diarrhea was found to occur between November and April of the following year. The genotype of rotavirus was dominated by G9 (82.76%), the P genotype was dominated by P[8] (80.46%), and the G/P combination was dominated by G9P[8] (83.87%). Norovirus was the main infection in the Calicivirus (87.21%). Conclusions From 2012 to 2017, viral diarrhea in children under 5 years of age in Shandong Province was mainly caused by Rotavirus infection, followed by Norovirus. The overall prevalence of viral diarrhea in Shandong was moderate in China, and autumn and winter were the main epidemic season for viral diarrhea.

Objective To investigate the expressions of spleen tyrosine kinase (Syk), c-Jun amino terminal kinase (JNK) and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in the heart tissue in SD rat model of diabetic cardiomyopathy, and to explore the relationship between Syk, JNK and NLRP3. Methods Clean male SD rats were randomly divided into the control (Ctrl) group and diabetic cardiomyopathy model (DCM) group. Rats of DCM group were treated with a single intraperitoneal injection of streptozotocin (STZ), while rats of Ctrl group were injected with the same dose of citrate buffer. The random blood glucose level and body weight were monitored every week until 20 weeks after STZ or citrate buffer injection, then all the rats were killed and their hearts were obtained. Rat H 9c2 cardiomyocytes were randomly divided into normal glucose treatment (NG) group, high glucose treatment (HG) group, Syk inhibitor control (BAY) group and Syk inhibitor high glucose (HG+BAY) group. The Syk and JNK phosphorylations and NLRP3 protein expression were detected by Western blot assay in the heart tissue of SD rats and H9c2 cardiomyocytes. The NLRP3, cysteine-containing aspartate specific protease 1(caspase-1) and interleukin (IL)-1β expressions at mRNA level were detected by reverse transcription-polymerase chain reaction (RT-PCR). Results The random blood glucose level was significantly increased (P<0.05) and the body weight was significantly decreased (P<0.05) in DCM group compared with those of Ctrl group. The expressions of cardiac p-Syk, p-JNK and NLRP3 at protein level were significantly increased in DCM group compared with those of Ctrl group (P<0.05). Furthermore, the mRNA levels of NLRP3, caspase-1 and IL-1β were significantly up-regulated (P < 0.05). BAY treatment significantly inhibited the high glucose-induced NLRP3, caspase-1 and IL-1β mRNA expressions and p-JNK, NLRP3 protein expressions in H9c2 cardiomyocytes (P < 0.05). Conclusion JNK phosphorylation and NLRP3 inflammasome activation induced by Syk play an important role in the pathogenesis of diabetic cardiomyopathy.

Ebola virus (EBOV) is an aggressive pathogen that causes a highly hemorrhagic fever syndrome in humans and other mammalian species.Early detection and proper treatment is the best defense against EBOV because of high mortality rate (70％-90％).Currently,there are eleven FDA approved Ebola tests,kits,or assays for emergency use,which can be divided into two main categories:rRT-PCR and viral antigen methods.In BSL 4 lab,rRT-PCR is the most sensitive technique to detect nucleic acid of Ebola virus,including Ebola Zaire (EZ1) rRT-PCR (TaqMan) Assay,Ebola Virus NP and VP40 Real-time RTPCR Assay,FilmArray NGDS BT-E and Biothreat-E test,RealStar Ebolavirus RT-PCR kit,LightMix Ebola Zaire rRT-PCR test,and Xpert Ebola Assay.Antigen-based technology (ReEBOV Antigen Rapid Test,and OraQuick Ebola Rapid Antigen Test) provides rapid Ebola antigen test without relying on special PCR equipment.How to develop,manufacture,and market point-of-care and field testing will be the next major challenge for EBOV on various samples.

BACKGROUND:Silver nanoparticles (AgNPs) show strong antibacterial effect and are not easy to have drug resistance. But the antibacterial mechanisms of AgNPs have not been wel developed.
OBJECTIVE:To explain the antibacterial mechanisms of AgNPs.
METHODS:We investigated the influence of Ti, TiO2 and TiO2 containing AgNPs onEscherichia coliand Staphylococcus aureus by bacterial inhibition ring test. Escherichia coli was cultured in LB liquid medium with 0, 5, 10 mg/L AgNPs. We measured the absorbance value of bacterial culture. DNA gel electrophoresis was used to study the effect of AgNPs onEscherichia coliDNA. Then we researched the character of apoptosis on Escherichia coli by Annexin V and PI staining, using flow cytometry.
RESULTS AND CONCLUSION:The inhibiting effect of Ti and TiO2 onEscherichia coliandStaphylococcus aureus was not obvious. But the inhibition rings of TiO2 containing AgNPs to bacteria appeared. The absorbance value of Escherichia coliculture was reduced whenEscherichia coliwas co-cultured with AgNPs. And this decrease tendency was in direct proportion with AgNPs concentration. AgNPs reduced the amount of DNA of Escherichia coli and this tendency was directly proportional with AgNPs concentration. TheEscherichia coli apoptosis rate induced by AgNPs was increased and this tendency was positively correlated to the AgNPs concentration. These results indicate that AgNPs can induce bacterial apoptosis to influence the growth of bacteria.

Objective To explore the association of lectin-like oxidized low-density lipoprotein (oxLDL) receptor-1 (LOX-1),CX3C chemokine receptor 1 (CX3CR1) with coronary artery stenosis disease and its outcomes.Methods A case-control study was conducted.A total of 176 cases of coronary artery stenosis which were confirmed coronary artery stenosis ≥ 50％ by coronary angiography(CAG) were served as case group from department of cardiology of TEDA International Cardiovascular Hospital of Tianjin from May 2011 to April 2013.A total of 129 patients without coronary artery lesion by CAG from this hospital in the same period were served as control group,which has no history of heart disease,liver and kidney dysfuction,brain disease,hematological disease,other disorders that could bring out atherosclerosis and thrombosis.General information and laboratory parameters,LOX-1,CX3CR1,uric acid (UA) and creatinine (CREA) were measured in 2 groups.These parameters of each group were compared,the levels of LOX-1 and CX3CR1 in one-vessel stenosis were compared than that in multi-vessels stenosis in case group,the correlations between LOX-1,CX3CR1 and Gensini score and other variables were analyzed.Comparison of the levels of LOX-1 and CX3CR1 between major adverse cardiovascular events (MACEs) group and nonmajor adverse cardiovascular event (MACE) group was made during follow up 1.5 years.MACEs in patients with different levels of LOX-1 and CX3CR1 were compared during 1.5-year follow up.All of the data were analyzed by SPSS 16.0 software.The independent-samples T test,Mann-Whitney U test,Chi-square test,Spearman correlation,Binary Logistic Regression and Kaplan-Meier probability were adopted for data analysis.Results Comparison between case group and control group,LOX-1:3.72 (1.44,8.15) μg/L vs 0.75(0.50,1.19) μg/L,z =11.072,P ＜0.001 ;CX3CR1:(2.82 ± 1.85) μg/L vs (2.32 ±0.79) μg/L,t =2.021,P ＜ 0.05 ; UA:(351.34 ± 94.82) μmol/L vs (326.74 ± 79.51) μmol/L,t =2.094,P ＜ 0.05 ;CREA:(70.86 ± 20.94) μmol/L vs (65.55 ± 12.96) μmol/L,t =2.077,P ＜ 0.05.CX3CR1 level was significantly higher in patients with multi-vessels stenosis (2.84 ± 1.78) μg/L than that in one-vessel stenosis(2.48 ± 1.64) μg/L,there was significance in difference (t =2.207,P ＜ 0.05).There were no statistically significant correlation between LOX-1,CX3CR1 and Gensini score (R was 0.032,0.079 respectively,P＞ 0.05).LOX-1 was negatively related to left ventricular ejection fraction(LVEF) (R =-0.272,P ＜ 0.01),but positively related to left ventricular end-diastolic diameter (LVDD)(R =0.190,P＜0.05),positively related to UA (R =0.121,P ＜ 0.05).Comparison between MACE group and nonMACE group,LOX-1:7.38(4.97,11.88)μg/L vs 3.52(1.45,7.75) μg/L,z =2.762,P ＜0.01;CX3CRl:(4.02 ±2.90) μg/L vs (2.67 ± 1.48) μg/L,t =3.086,P ＜0.01.LOX-1 and TG were independent risk effects of coronary artery stenosis disease.MACEs were increased in patients with high levels of LOX-1 after PCI during following up 1.5 years (comparison between high-LOX-1 group and lowLOX-1 group,the probability of non-MACE was 87.1％ (115/132) vs 97.7％ (43/44),Log-ranK test,x2 =6.957,P ＜ 0.01).Conclusions LOX-1 and CX3CR1 may be involved in the process of coronary artery stenosis,and a high level of LOX-1 may be associated with left ventricular systolic dysfunction in patients with coronary artery stenosis.Elevated LOX-1 level are closely related to afterwards MACE incidence after PCI in patients with coronary artery stenosis.

BACKGROUND:Bone marrow mesenchymal stem cel s have attracted widespread attention for the capabilities of self-renewal and muti-differentiation, which have been used in treatment of various diseases.
OBJECTIVE:To study the effect of three-dimensional spheroid culture system on the stemness and senescence of bone marrow mesenchymal stem cel s.
METHODS:Mesechyaml stem cel s were isolated from the bone marrow of C57/B6 mice, 3 weeks old, and cultured onto the culture plates coated with or without chitosan. After 5 days of culture, the cel phenotype and expression of stemness related markers CD44 and Sca-1 were analyzed by flow cytometry. PI and Annexin-V staining were used to detect cel apoptosis. Also,β-Gal staining was applied for identification of aging.
RESULTS AND CONCLUSION:The mouse mesenchymal stem cel s began to form spheroids on day 3. The stemness-related markers, including CD44 and Sca-1, expressed higher in spheroid mesenchymal stem cel s than the cel s under normal culturing. Compared with the normal culture group, the apoptosis and senescence of cel s from spheroid culture were lower. The results indicate that the formation of spheroids on chitosan films can increase the stemness, decrease the apoptosis and slow the senescence of mesenchymal stem cel s.

Objective To clarify the role of syk kinase in inflammasome activation in mouse peritoneal macrophages during Listeria monocytogenes (LM) infection. Methods Murine peritoneal macrophages were randomly divided into BAY treatment group, SB treatment group, WO treatment group, no treatment group and negative control group (NI). There were three wells in each group. The syk inhibitor BAY 117082, P38MAPK inhibitor SB203580 and PI3K inhibitor wotamine were used to treat murine peritoneal macrophages for 1h in BAY treatment group, SB treatment group and WO treatment group. Murine peritoneal macrophages were infected with LM for 24 h except NI group. The protein level of interleukin (IL)-18 in the supernatant was detected by ELISA kit. The activation condition of key molecule ASC in the infected-macrophages cyto-plasm was observed under fluorescence microscope. The phosphorylation levels of syk protein kinase at different time points during LM infection were determined by Western blot assay. Results There was no significant difference in IL-18 protein level before and after BAY treatment in NI group (P>0.05). The IL-18 protein level was significantly lower after LM infec-tion in BAY treatment group compared with that in no treatment group (P<0.05). In contrast, there was no significant differ-ence in IL-18 production between SB treatment group, WO treatment and no treatment group (P>0.05). Meanwhile, the per-centage of ASC-speck positive cells was obviously diminished in BAY treatment group compared with that in no treatment group (P<0.01). The phosphorylation levels of syk were significantly increased in 5 min, 15 min and 30 min post-infection. Conclusion Syk kinase signaling is involved in the inflammasomes activation upon Listeria monocytogenes infection in mu-rine macrophages.

Objective To explore the clinical value of the different components of glycosylated hemoglobin in pa-tients with coronary artery disease (CAD). Methods A total of 217 patients were divided into 3 groups:CAD group (groupⅠ, n=60), CAD patients without acute coronary syndrome (ACS) and with diabetes mellitus group (groupⅡ, n=60) and ACS patients with diabetes mellitus group (groupⅢ, n=97). Fifty-eight healthy volunteers in the same time period were selected as control group. The values of fructose glycosylated hemoglobin (HbA1a), lactose glycosylated hemoglobin (HbA1b), glucose glycosylated hemoglobin (HbA1c), hemoglobin P3 component (HbP3), hemoglobin A0 component (HbA0), unstable glycosyl-ated hemoglobin (LA1c/CHb1) and alkali-resistant hemoglobin (HbF) were measured. These parameters were compared be-tween 4 groups. Logistic regression was used to analyze factors that influencing CAD and CAD with diabetes mellitus. The re-ceiver operating characteristic (ROC) curve was used to analyze the diagnostic efficiency of these factors. Results There were significant differences in titers of HbA1b, HbA1c, HbP3 and HbA0 between groupⅠ, groupⅡ, groupⅢand control group (P＜0.01, or P＜0.05). There were no significant differences in levels of glycosylated hemoglobin parameters between groupⅡand groupⅢ(P>0.05). Logistic regression and ROC curve analysis showed that HbA1c and HbP3 were indepen-dent effects of CAD, and there were some diagnostic efficiency of CAD. The diagnostic efficiency of ROC curve was consis-tent in HbA1c and HbP3 between group Ⅱ and group Ⅲ. Conclusion Levels of HbA1b, HbA1c, HbP3 and HbA0 are closely related to CAD and CAD with diabetes mellitus. HbA1c and HbP3 are independent effects of CAD and, there are some diagnostic efficiency in CAD.

Objective To investigate the drug resistance and genotype of methicillin-resistant Staphylococcus (MRS), and to study the epidemiology of drug resistance in Staphylococcus. Methods Drug susceptibility tests were performed for 138 Staphylococcus strains clinically isolated, and mecA gene was detected with PCR. For mecA positive strains, Staphylococcal cassette chromosome mec (SCCmec) gene was detected by two multiplex PCR assays. Results Seven (10.8%) out of 65 Staphylococcus aureus strains were methicillin-resistant Staphylococcus aureus (MRSA) strains, and 44 (60.3%) out of 73 coagulase negative Staphylococcus strains were methicillin-resistant coagulase negative Staphylococcus (MRCNS)strains. There was statistical significance on the difference of isolation rates (x2 = 37. 05, P ＜0.01). No vancomycin or nitrofurantoin resistant strain was found. There were 52 (52/138, 37.7%) mecA positive strains, including 16 SCCmec type Ⅰ strains, 1 type Ⅱ strain, 13 type Ⅲ strains, 9 type Ⅳ strains and 4 type Ⅴ strains. Conclusions Drug resistance in MRS is increasingly serious. MRCNS strains are more popular than MRSA in clinic, and SCCmec Ⅰ and Ⅲ may account for most infections.