Background Permethrin is a commonly used pyrethroid insecticide and has been found to be potentially neurotoxic. Microglia are innate immune cells in the central nervous system and are involved in the development of a range of neurodegenerative diseases. Objective To observe possible toxic effects of permethrin on human microglia clone 3 (HMC3) in vitro and explore associated mechanism. Methods HMC3 were treated with 0, 10, 25, and 55 μmol·L⁻¹ permethrin for 72 h. Cell cycle and apoptosis were measured using flow cytometry. Cyclin-dependent kinase 1 (CDK1), cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin B2 (CCNB2), cellular tumor antigen p53 (p53), factor-related apoptosis (FAS), caspase 3 (CASP3), and H2A histone family member X (H2AX) were detected by quantitative real-time PCR (qPCR). The differential genes and enrichment pathways of HMC3 after 0 and 25 μmol·L⁻¹ permethrin treatment was analyzed by RNA sequencing. HMC3 was treated by 0, 10, 25, and 55 μmol· L⁻¹ permethrin for 72 h. The content of nitric oxide (NO) in the supernatant was detected using Griess reagent. The secretion level of interleukin-6 (IL-6) was detected by enzyme linked immunosorbent assay (ELISA). The mRNA expression levels of mitogen-activated protein kinase (MAPK) pathway (including MAPK1, MAPK8, and MAPK14), interleukin-1β (IL-1β), IL-6, and matrix metalloproteinase (MMP) families (including MMP1, MMP2, MMP3, and MMP9) were detected by qPCR. The protein expressions of phosphorylated p38 mitogen-activated protein kinase (p-p38), phosphorylated extracellular signal-regulated kinase (p-ERK), IL-1β, IL-6, and MMP1 were detected by Western blot. Results HMC3 was arrested in G2/M phase after 0, 10, 25, and 55 μmol·L⁻¹ permethrin treatment for 72 h, of which there was a statistically significant difference between the 55 μmol·L⁻¹ permethrin treatment group and the control group (P<0.01), and the mRNA expression of CDKN1A was up-regulated according to the qPCR (P<0.05). There was no statistically significant difference in the proportions of apoptosis between the groups (P＞0.05). The RNA sequencing showed that the differential genes were enriched in the MAPK pathway, and the mRNA expressions of MAPK1, MAPK8, and MAPK14 were up-regulated after the permethrin treatment at 55 μmol·L⁻¹ compared to the control group by qPCR (P<0.05). The Western blot revealed that, compared to the control group, the levels of p-p38 and p-ERK were increased after the 10 μmol·L⁻¹ permetrin treatment (P<0.05), the p-ERK level was increased after the 25 μmol·L⁻¹ permetrin treatment (P<0.05), and the p-p38 level was up-regulated after the 55 μmol·L⁻¹ permetrin treatment (P<0.05). The secretion of NO in the supernatant of HMC3 increased after permetrin treatment compared to the control group (P<0.05), the mRNA and protein expressions and the secretion of IL-6 showed an upward trend, the mRNA and protein expressions of IL-1β were up-regulated (P<0.05), and the mRNA and protein expressions of MMP1 were up-regulated in the 25 and 55 μmol·L⁻¹ permethrin groups (P<0.05). Conclusion Permethrin inhibits HMC3 cell proliferation in vitro, induces cell cycle arrest, activates MAPK pathway, and promotes the expression of inflammatory factors IL-1β and MMP1, which may be one of the mechanism of neurotoxicity induced by permethrin.

Objective:To investigate the epidemiological characteristics, diagnosis, treat-ment and prognosis of gallbladder cancer in China from 2010 to 2017.Methods:The single disease retrospective registration cohort study was conducted. Based on the concept of the real world study, the clinicopathological data, from multicenter retrospective clinical data database of gallbladder cancer of Chinese Research Group of Gallbladder Cancer (CRGGC), of 6 159 patients with gallbladder cancer who were admitted to 42 hospitals from January 2010 to December 2017 were collected. Observation indicators: (1) case resources; (2) age and sex distribution; (3) diagnosis; (4) surgical treatment and prognosis; (5) multimodality therapy and prognosis. The follow-up data of the 42 hospitals were collected and analyzed by the CRGGC. The main outcome indicator was the overall survival time from date of operation for surgical patients or date of diagnosis for non-surgical patients to the end of outcome event or the last follow-up. Measurement data with normal distribu-tion were represented as Mean±SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( Q1, Q3) or M(range), and com-parison between groups was conducted using the U test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Univariate analysis was performed using the Logistic forced regression model, and variables with P<0.1 in the univariate analysis were included for multivariate analysis. Multivariate analysis was performed using the Logistic stepwise regression model. The life table method was used to calculate survival rates and the Kaplan-Meier method was used to draw survival curves. Log-rank test was used for survival analysis. Results:(1) Case resources: of the 42 hospitals, there were 35 class A of tertiary hospitals and 7 class B of tertiary hospitals, 16 hospitals with high admission of gallbladder cancer and 26 hospitals with low admission of gallbladder cancer, respectively. Geographical distribution of the 42 hospitals: there were 9 hospitals in central China, 5 hospitals in northeast China, 22 hospitals in eastern China and 6 hospitals in western China. Geographical distribution of the 6 159 patients: there were 2 154 cases(34.973%) from central China, 705 cases(11.447%) from northeast China, 1 969 cases(31.969%) from eastern China and 1 331 cases(21.611%) from western China. The total average number of cases undergoing diagnosis and treatment in hospitals of the 6 159 patients was 18.3±4.5 per year, in which the average number of cases undergoing diagnosis and treatment in hospitals of 4 974 patients(80.760%) from hospitals with high admission of gallbladder cancer was 38.8±8.9 per year and the average number of cases undergoing diagnosis and treatment in hospitals of 1 185 patients(19.240%) from hospitals with low admission of gallbladder cancer was 5.7±1.9 per year. (2) Age and sex distribution: the age of 6 159 patients diagnosed as gallbladder cancer was 64(56,71) years, in which the age of 2 247 male patients(36.483%) diagnosed as gallbladder cancer was 64(58,71)years and the age of 3 912 female patients(63.517%) diagnosed as gallbladder cancer was 63(55,71)years. The sex ratio of female to male was 1.74:1. Of 6 159 patients, 3 886 cases(63.095%) were diagnosed as gallbladder cancer at 56 to 75 years old. There was a significant difference on age at diagnosis between male and female patients ( Z=-3.99, P<0.001). (3) Diagnosis: of 6 159 patients, 2 503 cases(40.640%) were initially diagnosed as gallbladder cancer and 3 656 cases(59.360%) were initially diagnosed as non-gallbladder cancer. There were 2 110 patients(34.259%) not undergoing surgical treatment, of which 200 cases(9.479%) were initially diagnosed as gallbladder cancer and 1 910 cases(90.521%) were initially diagnosed as non-gallbladder cancer. There were 4 049 patients(65.741%) undergoing surgical treatment, of which 2 303 cases(56.878%) were initially diagnosed as gallbladder cancer and 1 746 cases(43.122%) were initial diagnosed as non-gallbladder cancer. Of the 1 746 patients who were initially diagnosed as non-gallbladder cancer, there were 774 cases(19.116%) diagnosed as gallbladder cancer during operation and 972 cases(24.006%) diagnosed as gallbladder cancer after operation. Of 6 159 patients, there were 2 521 cases(40.932%), 2 335 cases(37.912%) and 1 114 cases(18.087%) undergoing ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) examination before initial diagnosis, respec-tively, and there were 3 259 cases(52.914%), 3 172 cases(51.502%) and 4 016 cases(65.205%) undergoing serum carcinoembryonic antigen, CA19-9 or CA125 examination before initially diagnosis, respectively. One patient may underwent multiple examinations. Results of univariate analysis showed that geographical distribution of hospitals (eastern China or western China), age ≥72 years, gallbladder cancer annual admission of hospitals, whether undergoing ultrasound, CT, MRI, serum carcinoembryonic antigen, CA19-9 or CA125 examination before initially diagnosis were related factors influencing initial diagnosis of gallbladder cancer patients ( odds ratio=1.45, 1.98, 0.69, 0.68, 2.43, 0.41, 1.63, 0.41, 0.39, 0.42, 95% confidence interval as 1.21-1.74, 1.64-2.40, 0.59-0.80, 0.60-0.78, 2.19-2.70, 0.37-0.45, 1.43-1.86, 0.37-0.45, 0.35-0.43, 0.38-0.47, P<0.05). Results of multivariate analysis showed that geographical distribution of hospitals (eastern China or western China), sex, age ≥72 years, gallbladder cancer annual admission of hospitals and cases undergoing ultrasound, CT, serum CA19-9 examination before initially diagnosis were indepen-dent influencing factors influencing initial diagnosis of gallbladder cancer patients ( odds ratio=1.36, 1.42, 0.89, 0.67, 1.85, 1.56, 1.57, 0.39, 95% confidence interval as 1.13-1.64, 1.16-1.73, 0.79-0.99, 0.57-0.78, 1.60-2.14, 1.38-1.77, 1.38-1.79, 0.35-0.43, P<0.05). (4) Surgical treatment and prognosis. Of the 4 049 patients undergoing surgical treatment, there were 2 447 cases(60.435%) with complete pathological staging data and follow-up data. Cases with pathological staging as stage 0, stage Ⅰ, stage Ⅱ, stage Ⅲa, stage Ⅲb, stage Ⅳa and stage Ⅳb were 85(3.474%), 201(8.214%), 71(2.902%), 890(36.371%), 382(15.611%), 33(1.348%) and 785(32.080%), respectively. The median follow-up time and median postoperative overall survival time of the 2 447 cases were 55.75 months (95% confidence interval as 52.78-58.35) and 23.46 months (95% confidence interval as 21.23-25.71), respectively. There was a significant difference in the overall survival between cases with pathological staging as stage 0, stage Ⅰ, stage Ⅱ, stage Ⅲa, stage Ⅲb, stage Ⅳa and stage Ⅳb ( χ2=512.47, P<0.001). Of the 4 049 patients undergoing surgical treatment, there were 2 988 cases(73.796%) with resectable tumor, 177 cases(4.371%) with unresectable tumor and 884 cases(21.833%) with tumor unassessable for resectabi-lity. Of the 2 988 cases with resectable tumor, there were 2 036 cases(68.139%) undergoing radical resection, 504 cases(16.867%) undergoing non-radical resection and 448 cases(14.994%) with operation unassessable for curative effect. Of the 2 447 cases with complete pathological staging data and follow-up data who underwent surgical treatment, there were 53 cases(2.166%) with unresectable tumor, 300 cases(12.260%) with resectable tumor and receiving non-radical resection, 1 441 cases(58.888%) with resectable tumor and receiving radical resection, 653 cases(26.686%) with resectable tumor and receiving operation unassessable for curative effect. There were 733 cases not undergoing surgical treatment with complete pathological staging data and follow-up data. There was a significant difference in the overall survival between cases not undergoing surgical treatment, cases undergoing surgical treatment for unresectable tumor, cases undergoing non-radical resection for resectable tumor and cases undergoing radical resection for resectable tumor ( χ2=121.04, P<0.001). (5) Multimodality therapy and prognosis: of 6 159 patients, there were 541 cases(8.784%) under-going postoperative adjuvant chemotherapy and advanced chemotherapy, 76 cases(1.234%) under-going radiotherapy. There were 1 170 advanced gallbladder cancer (pathological staging ≥stage Ⅲa) patients undergoing radical resection, including 126 cases(10.769%) with post-operative adjuvant chemotherapy and 1 044 cases(89.231%) without postoperative adjuvant chemo-therapy. There was no significant difference in the overall survival between cases with post-operative adjuvant chemotherapy and cases without postoperative adjuvant chemotherapy ( χ2=0.23, P=0.629). There were 658 patients with pathological staging as stage Ⅲa who underwent radical resection, including 66 cases(10.030%) with postoperative adjuvant chemotherapy and 592 cases(89.970%) without postoperative adjuvant chemotherapy. There was no significant difference in the overall survival between cases with postoperative adjuvant chemotherapy and cases without postoperative adjuvant chemotherapy ( χ2=0.05, P=0.817). There were 512 patients with pathological staging ≥stage Ⅲb who underwent radical resection, including 60 cases(11.719%) with postoperative adjuvant chemotherapy and 452 cases(88.281%) without postoperative adjuvant chemotherapy. There was no significant difference in the overall survival between cases with postoperative adjuvant chemo-therapy and cases without post-operative adjuvant chemo-therapy ( χ2=1.50, P=0.220). Conclusions:There are more women than men with gallbladder cancer in China and more than half of patients are diagnosed at the age of 56 to 75 years. Cases undergoing ultrasound, CT, serum CA19-9 examination before initial diagnosis are independent influencing factors influencing initial diagnosis of gallbladder cancer patients. Preoperative resectability evaluation can improve the therapy strategy and patient prognosis. Adjuvant chemotherapy for gallbladder cancer is not standardized and in low proportion in China.

Objective:To explore the association between statins and colorectal cancer and provide evidence for the prevention of colorectal cancer.Methods:Literatures about statins and colorectal cancer published from January 2000 to January 2020 were retrieved from CNKI, Wanfang data, PubMed and Cochrane Library database. The literatures which met the inclusion criteria were collected, and the Newcastle-Ottawa Scale and Jadad score were used to assess the studies. Meta-analysis was performed with statistical software Revman 5.0 and Stata 12.1.Results:A total of 31 studies, involving more than 1.62 million subjects, were included in the analysis. The case-control study ( RR=0.93, 95% CI: 0.88-0.98), the cohort study ( RR=0.75, 95% CI: 0.63-0.88) and the randomized controlled trial ( RR=0.79, 95% CI: 0.65-0.97) showed moderate protective effect of statins. Using statin <5 years ( RR=0.86, 95% CI: 0.76-0.96), average daily dosage ≥34 mg ( RR=0.81, 95% CI: 0.66-0.98) and lipid-soluble statins ( RR=0.86, 95% CI: 0.74-0.99) also had preventive effect on colorectal cancer; while lovastatin ( RR=1.07, 95% CI: 1.00-1.14) increased the risk of colorectal cancer. Conclusion:Statins have protective effect on colorectal cancer.

Objective:To investigate the molecular characteristic and antimicrobial resistance of Staphyloco- ccus aureus ( S. aureus) isolated from children with pneumonia, in order to provide the evidence for clinical diagnosis and treatment. Method:s The S. aureus strains isolated from children diagnosed as S. aureus pneumonia in the Beijing Children′s Hospital, Capital Medical University, between January 2016 and March 2017 were collected.Methicillin-resistant S. aureus(MRSA)and Methicillin-susceptible S. aureus(MSSA)were identified using the cefoxitin disc method and the detection of the mecA gene. S. aureus isolates were characterized by multilocus sequence typing (MLST) and Staphylococcal protein A (spa) typing, and MRSA strains were characterized by Staphylococcal chromosome cassette (SCC mec) typing.Besides, 21 superantigens (SAgs) genes, panton-valentine leucocidin (PVL) genes, adhesion genes fnbb and cna were detected by PCR; E-test was used to detect in vitro drug sensitivity of 14 antibiotics. Result:s A total of 42 S. aureus were collected, and 21 isolates were MSSA, the same to MRSA, while MSSA strains had relatively dispersed typing, with ST25-t078 (14.2%) as the most common one.ST59-SCC mecⅣa-t437 (71.4%) were the most predominant clones of MRSA.Of the 42 isolates, 36 strains (85.7%) had at least 1 superantigen gene, and sek- seq (21.4%) was the main virulence genotype.The ratio of pvl in MRSA strains (52.3%)was significantly higher than that in MSSA strains (14.2%), while the detection rate of fnbB and cna in MRSA(9.5%, 9.5%) was significantly lower than that in MSSA(42.8%, 47.6%), and the differences were statistically significant (all P<0.05). Ninety point four percent (38/42 strains) of the S. aureus isolates were multidrug resistant. Conclusions:In children with S. aureus pneumonia, MRSA has a high detection rate, and its dominant clonotype is ST59-SCC mecⅣa-t437.The pre-valence of superantigen genes and the multidrug resistant rate of S. aureus are relatively high.MRSA strains often carry pvl, while MSSA strains usually carry fnbB and cna gene.

Objective:To investigate the distribution of fungal species and their sensitivity to antifungal drugs in children with invasive fungal infections.Methods:All the fungal strains primarily isolated from the sterile parts of children in Beijing Children′s Hospital, Capital Medical University from January 2010 to December 2016 were analyzed.The sensitivity of strains to 5-Fluorocytosine, Fluconazole, Amphotericin B, Itraconazole and Voriconazole was tested using ATB-FUNGUS 3 yeast drug sensitivity test strip in accordance with the standards of Clinical and Laboratory Standards Institute M27-A2.Statistical analysis of data was performed using WHONET 5.6 software.Results:Among 236 fungi isolated from aseptic samples, 64.0% (151 strains) were from blood, 22.9%(54 strains) from cerebrospinal fluid, 3.8%(9 strains) from bone marrow, 3.8%(9 strains) from ascites, 3.4%(8 strains) from pleural effusion and 2.1%(5 strains) from tissues.The top 3 dominant species detected in the 236 strains of fungi were Candida spp.(175 strains, 74.2%), Cryptococcus neoformans (31 strains, 13.1%), and Saccharomyces spp.(9 strains, 3.8%). Among the Candida spp., the main isolates were Candida albicans (107 strains, 61.1%), Candida parapsilosis (33 isolates, 18.9%), and Candida tropicalis (13 isolates, 7.4%). Rare fungi of Penicillium marneffei, Exophiala spp.and Rhizopys spp.were also detected. Candida spp.was 100% sensitive to Amphotericin B. Cryptococcus neoformans was 100% sensitive to Fluconazole, Voliconazole and Amphotericin B. Conclusions:The most common strain isolated from pediatric patients with invasive fungal infections is Candida spp., especially Candida albicans. Cryptococcus neoformans causes central nervous system and systemic disseminated infections that can′t be ignored.Amphotericin B has higher antibacterial activity against Candida spp.and Cryptococcus neoformans.Separation of species of invasive fungal infections and monitoring of drug resistance in children should be strengthened to effectively control invasive fungal infections and facilitate rational use of antifungal drugs.

Objective:To assess the effect of stone and urine bacteria culture on the treatment of postoperative infection in percutaneous nephrolithotomy (PCNL).Methods:Between September 2016 and September 2018, 1060 patients with kidney stones treated with first-stage PCNL were included in the study. There were 614 male and 446 female patients, with the mean age (52.4±12.2) years. The mean stone burden was (1 499.6±1 435.3) mm 2. The midstream urine sample and the stone sample were sent for bacterial culture, identification of bacterial strain and antimicrobial susceptibility tests. The results of urine culture (UC), stone culture (SC) and their antimicrobial susceptibility, the details of perioperatively administered antibiotics and postoperative infections were recorded. The relationship between the postoperative infection and the SC was analyzed. Results:In 1 060 patients, 22 bacterial species were identified in UC and 52 bacterial species were identified in SC. The positive rate was higher in SC than in UC[31.8%(337/1 060)vs. 20.9%(222/1 060), P<0.001]. Escherichia coli was the most common bacteria in both UC and SC, but was more prevalent in UC than in SC [52.3%(116/222)vs. 43.6%(147/337), P<0.05]. E. coli cultured from UC and SC had high resistance to ampicillin, cefazolin, ceftriaxone, cefotaxime, levofloxacin, ciprofloxacin (all resistance rate >40%), but were sensitive to meropenem, cefoperazone/sulbactam, piperacillin/tazobactam, and amikacin (all resistance rate <10%). There was no statistical difference in the antibiotic resistance rates of E. coli from the UC and SC (all P >0.05). There were 111 (10.5%) patients who developed fever and 22 (2.1%) who developed urosepsis postoperatively. The incidences of postoperative fever and urosepsis were higher in the patients with positive SC than the patients with negative SC [23.7%(80/337)vs. 4.3%(31/723); 4.2%(14/337)vs. 1.1%(8/723), P<0.05]. Even in patients with negative UC, The incidence of postoperative fever was higher in the group with positive SC than the group with negative SC [17.9%(30/168) vs. 4.2%(28/670), P<0.05]. The incidence of postoperative fever in SC positive patients was lower if they were treated with sensitive antibiotics to the bacteria in stone than those treated with nonsensitive antibiotics [17.5%(22/126) vs. 27.5%(58/211), P<0.05]. Conclusions:The SC had high rate of culture positive, complicated bacterial species and high rate of multi-drug resistant. Positive SC was associated with increased incidence of postoperative infection even if the patients had negative UC. The SC might have a importance clinical value in the treatment of postoperative infection in PCNL.

Objective To investigate the reproducibility of magnetic resonance intravoxel incoherent motion in body diffusionG weighted imaging (IVIMGDWI)for normal lumbar disc scanning.Methods 50 healthy volunteers were enrolled with informed consent,30 males and 20 females,2 5.20±2.04 years old.Using 3.0T MR on the lumbar spine,the sagittal T1 WI,the sagittal,axial T2 WI and sagittal IVIMGDWI sequences were scanned once,then the second sagittal IVIMGDWI sequence was scanned after 4 hours.The IVIMGDWI sequence used 10 b values (0,10,20,40,60,80,100,200,400,600 s/mm2 ).The discs were graded according to the Pfirrmann grading standard.The ADCfast ,ADCslow ,and f values of each intervertebral disc were measured by two doctors at the postGprocessing workstation.Paired tGtest was used to analyze whether there was a difference between the two scans.The intraGgroup correlation coefficient (ICC)was used to analyze the consistency of the ADCfast ,ADCslow ,and f values of the two acquisitions (P＜0.05)and the consistency of the ADCfast ,ADCslow,and f values between the different doctors (P＜0.05).The IVIMGDWI imaging was evaluated to measure the repeatability of normal lumbar discs. Results Of the 50 healthy volunteers,230 intervertebral discs matched the criteria(Pfirrmann gradeⅠandⅡ).The ADCslowvalue between the two scans was significantly different (t＝2.460,P＜0.05),and the differences in ADCfast and f values were not significant (t＝－0.418,1.273,P＞0.05). The consistency of ADCfast ,ADCslow ,and f values for the two scans were generally (ICC＝0.478,0.306,0.316,P＜0.05 ).Different observers had good consistency in the measurement of interverG tebral disc ADCfast ,ADCslow,and f values (ICC＝0.929,0.909, 0.9 1 1 ,P＜0.05).Conclusion The IVIMGDWI imaging has good consistency in the measurement of normal lumbar disc between different observers.The consistency of IVIMGDWI in two scans of normal lumbar intervertebral discs is general,which may be due to the time interval between the two scans.Because ADCslow represents the diffusion of water molecules in tissues,the microenvironment in the lumbar intervertebral disc has changed,resulting in the difference of ADCslow value.As for the problem that different scanning time may lead to the change of IVIMGDWI data,we will study it further.

Objective: To study the clinical and molecular characteristics of Staphylococcus aureus(S.aureus ) isolated from neonates of Beijng Children′s Hospital. Methods: The clinical information of S. aureus infection in newborns of Beijing Children′s Hospital from February 2016 to January 2017 was collected.The molecular biological characteristics of S. aureus isolates were detected.Methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus(MSSA)were identified, using the cefoxitin disc method and the detection of the mecA gene.Multilocus sequence typing(MLST)and spa typing were analyzed using the PCR, and the staphylococcal chromosomal cassette mec(SCCmec) type was analyzed for the MRSA isolates.Eleven adhesion gene and three virulence genes(pvl, psma, hlα )were also detected by PCR.Antimicrobial susceptibility testing was performed by agra dilution method or E-test method. Results: The total of 57 cases of neonatal S. aureus infection were collected during the study.The most common clinical diagnosis was 38 cases (66.7%) of pneumonia and 28 cases (49.1%) of skin infection syndrome (SSTI). There were 31 cases (54.4%) with MRSA infection and 26 cases (45.6%) with MSSA infection.The proportion of SSTI in the MRSA group (64.5%) and the infection of more than 2 sites (61.3%, 19/31) were significantly higher than those in the MSSA group (30.8%, 8/26 and 23.1%, 6/31). There were 16 MLST types and 29 spa types, the most common ones were ST59 (40.4%) and t437 (33.33%), respectively.The most common popular clones of MRSA and MSSA were ST59-SCCmecIVa-t437 (54.8%) and ST22-t309, respectively(11.5%). The sdrE carrying rate of MRSA was higher than that of MSSA, while the sdrD and cna carrying rates were lower than those of MSSA (P<0.05). The other adhesion and virulence gene carrying rates were not significantly different between the two strains.The multi-drug resistance rate of all strains was 61.4%(35/57). Except for lactam antibiotics, the most common resistant phenotypes of MRSA and MSSA were ERY-CLI, accounting for 74.2% and 26.9%, respectively. Conclusion The main types of neonatal S. aureus infection in our hospital were pneumonia and SSTI.SSTI and multi-site infections of MRSA infection are more common.MRSA and MSSA isolates have clonal dissemination characteristics.The most common clones are ST59-SCCmecIVa-t43 and ST22-t309, which show no significant differences in the status of carrying virulence factors between them.The multi-drug resistance rate of neonatal S. aureus isolates is higher.

Objective To investigate the distribution characteristics and changing tendency of urinary tract stones.Methods From January 2011 to May 2017,clinical data of 15 269 patients treated in our center was retrospectively reviewed.The stone components were detected by the automatic stone infrared spectroscopy system and the predominant components were recorded.There were 9 019 male patients and 6 250 female patients.The patients were divided into four groups according to their age,including group A ≤ 18 years;group B 19-40 years;group C 41-60 years;and group D ＞ 60 years.Compared the distribution characteristics of urinary tract stones of patient in different groups of sex,age and calendar year.Results Calcium oxalate stones were more prevalent in males than females [6 221 (69.0％)vs.3 582 (57.3％),P ＜ 0.001],but calcium phosphate stones [210 (3.4％) vs.210 (2.3％)],magnesium ammonium phosphate stones [230(3.7％) vs.165 (1.8％)] and carbonate apatite stones [1 328 (21.3％) vs.1 030 (11.4％)] were more common in females than males (P ＜ 0.001,respectively).The proportion of uric acid stones in group D [679(20.7％)] was higher than that in group A [23(9.1％)],group B[260(7.9％)],group C [1 163 (13.8％)] (P ＜0.001,respectively).The peak of carbonate apatite stones was showed in group B [652(19.7％)] (P＜0.001,respectively).Ammonium urate stones [9(3.5％)] and cystine stones [36 (14.2％)] were more frequent in group A(P ＜0.001,respectively).In adults,the percentage of uric acid stones increased with age,such as group B [260(7.9％)],group C [1 163(13.8％)],group D [679 (20.7％)].And the carbonated apatite stones decreased with age,such as group B [652 (19.7％)],group C [1 270(15.1％)],group D [416(12.7％)] (P ＜0.001,respectively).Further analysis showed the proportion of calc ium oxalate (OR =0.944,95 ％ CI 0.927-0.962,P ＜ 0.001),ammonium urate stones (OR =0.854,95％ CI 0.742-0.982,P =0.027) decreased,while calcium phosphate (OR =1.192,95％ CI 1.127-1.261,P ＜0.001),uric acid (OR =1.042,95％ CI 1.015-1.069,P =0.002) and ammonium magnesium phosphate (OR =1.078,95％ CI 1.019-1.141,P =0.009) stones increased with time.Conclusions The distribution of stones was different in genders and age.Calcium oxalate stones were more common in male patients,while ammonium magnesium phosphate and carbonate apatite stones were more common in female patients.Uric acid stones were more frequent in patients older than 60,while carbonate apatite were more frequent in the 19-40 age group.The proportion of calcium oxalate and ammonium urate stones showed a downward trend,whereas calcium phosphate,uric acid and magnesium ammonium phosphate stones increased with time.

Objective To investigate the molecular characteristics,virulence genes and antimicrobial susceptibility to Staphylococcus aureus strains isolated from children with skin and soft tissue infections (SSTIs) in Beijing.Methods A total of 52 Staphylococcus aureus isolates were collected from children with SSTIs in Beijing Children's Hospital,Capital Medical University,and the clinical data were collected and analyzed.Methicillin-resistant Staphylococcus aureus(MRSA) and methicillin-susceptible Staphylococcus aureus(MSSA) were identified by using the cefoxitin disc method and the detection of mecA gene.Multilocus sequence typing (MLST) and staphylococcal protein A (spa) typing were analyzed by the PCR method,and the staphylococcal chromosomal cassette mec (SCCmec) type was analyzed for the MRSA isolates.The pvl,eta,etb,tsst-1 and hlg genes were also detected by PCR.The susceptibility strains to 16 antibiotics were evaluated by using the agar dilution method.Results A total of 52 Staphylococcus aureus SSTIs patients,30 with MRSA infections and 22 with MSSA infections were included in the study.There were 23 patients (44.2％) less than 1 year old.The most frequent infections were the newborn omphalitis (12/52 strains,23.1％)and abscess(11/52 strains,21.2％).ST59-MRSA-SCCmecⅣa-t437 was the most predominant clones of MRSA isolates.Among the MSSA isolates(14/30 strains,46.7％),no significant epidemic clone was found.Ten sequence types (STs) and 14 spa types were identified in MSSA,and the most common types were ST22(6/22 strains,27.3％)and t309 (5/22 strains,22.7％),respectively.Notably,the multidrug resistant rates of MRSA and MSSA isolates were all ＞ 85％.The percentages of the Staphylococcus aureus SSTIs strains resistant to Erythromycin,Penicillin,Chloramphenicol and Clindamycin were 100.0％,94.2％,69.2％ and 63.5％,respectively.The tested isolates were susceptible to Trimethoprim/Sulfamethoxazole,Mupirocin,Fusidic acid,Tigecycline,Linezolid and Vancomycin.The pvl gene's positive rate was 40.4％,and no significant difference between MRSA and MSSA was observed (P ＞ 0.05).Eta and etb genes were detected in 2 patients with staphylococcal scalded skin syndrome.Conclusions The Staphylococcus aureus SSTIs strains are most frequently isolated from newborn omphalitis and abscess in Beijing.The multidrug resistant rate is relatively high,so the erythromycin and clindamycin should not be preferred in empiric treatment of children with Staphylococcus aureus SSTIs.The prevalence of pvl gene is 40.1％.ST59-MRSA-SCCmecⅣa-t437 is the common clone of MRSA,while the MSSA isolates have a more diverse genetic background.