Influence of built environment on circulatory disease mortality: A case study of 17 cities in China / 环境与职业医学

Background In view of circulatory diseases, most previous studies focused on the impacts of air pollution and meteorological factors, while ignoring the influence of built environment. Objective To investigate and quantify the impact of built environment on circulatory diseases in China. Methods Circulatory disease mortality data and built environment data (including urban greenery coverage, urban land use, urban land use mix, urban road facilities and urban medical facilities) of 17 cities in China from 2000 to 2019 were collected. Multiple linear regression was used to analyze which built environment elements had significant influence on circulatory diseases, and to quantify their effects. Furthermore, the changes of built environment indicators on circulatory disease mortality were evaluated under different levels of urban economic development and various air quality. Results The built environment affected the mortality of circulatory diseases during the study period (P<0.05). Urban green space and commercial land area were negatively correlated with circulatory disease mortality, and regression coefficients were −0.550 and −0.280, respectively (P<0.05). On the contrary, the increase of urban road area, residential land ratio, and the degree of land use mix were positively associated with circulatory disease mortality, and their regression coefficients were 0.322, 0.283, and 0.176, respectively (P<0.05). When the level of urban economic development was low, the impact of commercial land use ratio on circulatory diseases was stronger, and the regression coefficient was −0.476 (P<0.05). When urban air pollution worsened, the impacts of per capita green coverage area and per capita urban road area on the disease were more prominent, and the regression coefficients were −0.528 and 0.372, respectively (P<0.05). Conclusion There is a significant correlation between urban built environment and mortality of circulatory diseases. To be specific, circulatory disease mortality has a negative correlation with per capita green coverage area and commercial land use ratio, and a positive correlation with per capita urban road area, residential land ratio and degree of land use mix.

Expert consensus on microbiome sequencing and analysis / 生物工程学报

In the past ten years, the research and application of microbiome has continued to increase. The microbiome has gradually become the research focus in the fields of life science, environmental science, and medicine. Meanwhile, many countries and organizations around the world are launching their own microbiome projects and conducting a multi-faceted layout, striving to gain a strategic position in this promising field. In addition, whether it is scientific research or industrial applications, there has been a climax of research and a wave of investment and financing, accordingly, products and services related to the microbiome are constantly emerging. However, due to the rapid development of microbiome sequencing and analysis related technologies and methods, the research and application from various countries have not yet unified on the standards of technology, programs, and data. Domestic industry participants also have insufficient understanding of the microbiome. New methods, technologies, and theories have not yet been fully accepted and used. In addition, some of the existing standards and guidelines are too general with poor practicality. This not only causes obstacles in the integration of scientific research data and waste of resources, but also gives related companies unfair competition opportunity. More importantly, China still lacks national standards related to the microbiome, and the national microbiome project is still in the process of preparation. In this context, the experts and practitioners of the microbiome worked together and developed the consensus of experts. It can not only guide domestic scientific research and industrial institutions to regulate the production, learning and research of the microbiome, the application can also provide reference technical basis for the relevant national functional departments, protect the scale and standardized corporate company's interests, strengthen industry self-discipline, avoid unregulated enterprises from disrupting the market, and ultimately promote the benign development of microbiome-related industries.

Evaluation of three MALDI-TOF MS systems for the identification of common microorganisms / 中华检验医学杂志

Objective To compare the efficiency of domestic MALDI-TOF MS systems Autof MS, Korea Asta MicroIDsys and Bruker Biotyper for common microorganisms identification. Methods This is a methodological comparison study. A total of 169 strains were isolated either from food in our laboratory since 2011 to 2018 or clinical samples in Chinese PLA General Hospital since 2016 to 2018. A total of 39 genus, 95 species were identified through Vitek2 Compact combined with 16S rDNA or ITS sequencing. Among them, a total of 93 Gram-negative bacteria strains, 65 Gram-positive bacteria strains, and 11 yeast strains were identified by three MALDI-TOF MS systems parallelly, while using extended direct smear method for sample preparation. The SPSS 18.0 software was used for data Statistical analysis. Results By Mass spectrometry identification, when 169 strains were at the species level confidence score and acceptable score level, 91.12％ (154/169) was correctly identified to species level by Autof MS system, 86.39％ (146/169) by ASTA MS system, and 81.66％ (138 / 169) by Bruker Biotyper MS system. The difference of identification accuracy to species level between Autof MS and Bruker Biotyper MS was statistically significant. Besides, the accuracy of genus identi fi cation was 98.82％ (167 / 169) by Autof MS mass spectrometry system and 97.04％ (164 / 169) by both ASTA MicroIDsys and Bruker Biotyper mass spectrometry system. The differences of identification accuracy to genus level among the three MS systems were not significant. Conclusions All of the three MS systems have good identification capability for common microorganisms. Autof MS systems performed slightly better than Bruker Biotyper MS systems in species level identification.

Epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana isolated from retail chicken carcasses in six provinces, China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana (S. Indiana) isolated from retail chicken carcasses in six provinces of China.</p><p><b>METHODS</b>A total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing.</p><p><b>RESULTS</b>Among 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing: 11.67% (99/874), Jilin: 8.20% (60/726), Guangdong: 1.39% (7/502), Jiangsu: 15.61% (42/260), Shaanxi: 8.56% (16/186), Inner Mongolia: 0 (0/81)), and 224 of them were identified as S. Indiana. 213 (95.10%) isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86% (40/224) of them were resistant to all antibiotics tested except carbapenems, and 50.89% (114/224) of them resistant to 9 antibiotics, additionally, 25.45% (57/224) of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions.</p><p><b>CONCLUSION</b>The results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.</p>

Using spiral coating technique to evaluate the activity of rat liver S9 prepared by combination inducing method / 中国比较医学杂志

Objective To reduce experimental costs and improve the utilization of S9, we use spiral coating technique to evaluate the activity of rat liver S9 prepared by combination inducing method as well as to establish cryopreservation method.Methods Using spiral coating technique and Ames test to evaluate the activity of self-made rat liver S9 and commercially available S9 separately.We use glycerinum as protective agent to establish cryogenic storage method, so that S9 can be in liquid form stored at -20 °C in the refrigerator.Results In the Ames assay as well as using spiral coating technique, the number of revertant colonies had dose-response relationship among the dose of S9.When conditions were the same, the number of revertant colonies in positive control was at the approximate level in presense of self-made rat liver S9 and commercially available S9 respectively.When S9 ( concentration of 38%) was added to the amount at 1.48 ~6.62 μL /μL broth dose of bacteria, it can significantly induced Salmonella typhimurium histidine strains TA100, reverse mutation rates were three times more than the control group.Conclusions Spiral coating technique can successfully evaluate the activity of rat liver S9.The inducing method of combination of PB and BF can take the place of the unducing method of PCBs in the preparation of Liver homogenate S9.

Enumeration and antimicrobial resistance of Campylobacter species from retail chicken carcasses / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine Campylobacter contamination level and antimicrobial resistance patterns from chicken carcasses in supermarkets and farmer's markets of 9 districts in Beijing.</p><p><b>METHODS</b>From August 2012 to July 2013, whole chicken carcasses (n = 240) were collected from 27 supermarkets and 18 farmer's markets of nine districts in Beijing. The level of Campylobacter contamination was enumerated by plate counting method using the modified Karmali and modified Preston agar. Presumptive Campylobacter isolates were identified and characterized by gram stain, agglumination test and a multiplex PCR method. The level of Campylobacter contamination was calculated following the USDA/FSIS Campylobacter enumeration method. Selected 151 Campylobacter isolates were further characterized by minimal inhibitory concentrations(MICs) of eight antimicrobials.</p><p><b>RESULTS</b>A total of 26.3% (63/240) of the retail whole chicken carcasses were contaminated by Campylobacter and 151 Campylobacter isolates were recovered, including 85 Campylobacter jejuni isolates and 66 Campylobacter coli isolates. The P25, P50, P75 of Campylobacter contamination concentration were 7.5, 45.0 and 350.0 CFU/g, respectively. The antimicrobial resistance rate of C. jejuni and C. coli were as the following: azithromycin(AZI, 13% (11/85), 82% (54/85)), chloramphenicol (CHL, 33% (28/85), 42% (28/85)), ciprofloxacin (CIP, 95% (81/85), 100% (85/85)), doxycycline (DOX, 38% (32/85), 80% (53/85)), erythromycin (ERY, 12% (10/85), 82% (54/85)), gentamicin (GEN, 25% (21/85), 68% (45/85)), tetracycline (TET, 67% (57/85), 73% (62/85)), all isolates were susceptible to meropenem (MEP). The multi-drug resistance ratio of C. jejuni (55% (47/85) )was significantly lower than that (86% (57/66) )of C. coli (χ(2) = 16.70, P < 0.01). Among 151 Campylobacter isolates, 21 antimicrobial resistance patterns were identified, including 20 patterns among C. jejuni isolates and 10 patterns among C.coli isolates. Among C.jejuni isolates, CIP-DOX-TET was dominant (22% (19/85)), followed by CIP-TET (14% (12/85)), CHL-CIP-TET(9% (8/85)) and CHL-CIP-GEN (7% (6/85)). Among C.coli isolates,AZI-CHL-CIP-DOX-ERY-GEN-TET (35% (23/66)) was the dominant, followed by AZI-CIP-DOX-ERY-GEN-TET (21% (14/66) )and AZI-CIP-DOX-ERY-TET(15% (10/66)).</p><p><b>CONCLUSION</b>Our findings showed a high prevalence and concentration of Campylobacter contamination in retail chicken carcasses of nine districts in Beijing, especially the on-site slaughtered chicken from the farmer's markets. The resistance levels of these recovered Campylobacter isolates were serious.</p>

Characterization of imipenem non-susceptible Pseudomonas aeruginosa isolates from patients without carbapenem treatment / 中华检验医学杂志

Objectives To investigate characterization of imipenem resistance among imipenem non susceptible Pseudomonas aeruginosa isolated from patients who treated without imipenem and explore risk factors of imipenem resistance.Methods From April,2006 to March,2008,a total of 37 non-susceptible to imipenem without imipenem therapy isolates were collected from affiliated 3201st Hospital of Medical College of Xi'an Jiaotong University.The minimum inhibition concentration (MIC) to 11 antimicrobial agents were determined by the broth dilution method.We also tested imipenem MIC combined with efflux pump inhibitor PAβN.PCR was performed to check for the presence of carbapenem-hydrolylzing MBL genes and oprD gene.The expression level of oprD2 and ampC were evaluated by qRT-PCR.Molecular typing was performed using PFGE.Results There is significant difference ( t =- 2.9004,P ＜ 0.01 ) of the average number days of therapy between with two or more antibiotics in the 16 patients (20.0 ± 9.5 ) d and that with only one antibiotic in the other 21 patients ( 12.6 ± 4.4 ) d before imipenem-non-susceptible strains were isolated.In all 37 strains,32 strains showed resistance to more than three antibiotics.The MBL gene ( IMP-9 ) was only found in one strain,but its phenotype is negative,oprD2 gene from the 29 strains were found forward inserted by ISpa1328.Thirty-five isolated were considered to have no oprD expression.The patterns of the total DNA of 37 strains appeared six PFGE types.The 26 strains belonged to C2 PFGE type.In the presence of PAβN,all 37 strains increased sensitivity to meropenem.Conclusion Fluoroquinolones and cephalosporins treatment could play an important role in imipenem non-susceptible production in the research isolates.

Plasmid-mediated quinolone resistance in Escherichia coli strains isolated from food animals / 中华微生物学和免疫学杂志

Objective To study on plasmid-mediated quinolone-resistant in Escherichia coli strains isolated from fecal samples of chicken and swine from the nine farms around our country.Methods Antimi-crobial susceptibility testing was carried out by broth microdilution testing,gyrA,gyrB,parC,qnr and aac (6')- Ⅰ b-cr were examined by PCR,and the products were sequenced.Conjugation experiment was carried out to proved that the plasmid-mediated quinolone resistance was transferable.Results In the total 818 animal isolates,qnr and aac genes were detected in 38 (4.6%) and 75 (9.2%) strains.The qnrA,qnrB,and qnrS genes were detected in 1 (0.1%),9 (1.1%) and 28 (3.4%) of the isolates.All isolates were negative for qnrC,qnrD genes.Conclusion There is a close relationship between high level quinolone resistance and plasmid-mediated quinolone resistance.The results of the current study highlight food-producing animals as a potential reservoir of antimicrobial-resistant bacteria and clinically important resistance genes.More attention should be paid to the surveillance of such strains.

Contributions of different quinolone resistance mechanisms in Escherichia coli / 中华微生物学和免疫学杂志

Objective To characterize the roles of different quinolone resistance mechanisms in quinolone-resistant Escherichia coli isolates,including different topoisomerase point mutations,efflux pumps and outer membrane proteins.Methotis Through homologous gene recombination methods,different quinolone-resistant mechanisms of E. coli mutants were constructed and the susceptibility changes of these mutants to different antimicrobials were measured.Resuits Efflux pumps AcrAB and outer membrane protein TolC played different roles in different E. coli isolates.Compared with other mechanisms,the mutations in topoisomerases played a dominant role in quinolone resistance.Only the mutations jn parC had no effect on quinolone resistance,which further confirmed parC was the secondary target of quinolones in E.coli.Fluoroquinolone susceptible E.coli would automatically become highly resistant to quinolones after acquiring the point mutations in both gyrA(S83L,D87N)and parC(S80I,A108V),but not requiring the over-expres-sion of efflux.Conclusion The mutations in topoisomerases play a dominant role in E.coli quinolone resistance,and the mutations in both gyrA and parC are required.

Chromosome-and plasmid-mediated fluoroquinolones-resistance in Escherichia coli strains isolated from food animals and healthy people around farm / 中华微生物学和免疫学杂志

Objective To study on chromosome-and plasmid-mediated fluoroquinolones-resistant in Escherichia coli isolated from fecal samples of chicken,swine and people around the farm.Methods Anti-microbial susceptibility testing was carried out by disk diffusion testing and bmth microdilution testing.gyrA,gyrB,parC,pareE,qnr and aac(6')-I b-cr were examined by PCR,and the products were sequenced.Ex-presion of aac(6')-I b-cr by conjunction was tested too.Results The resistance to antimicmbial agents was much higher in strains isolated from chicken than that from swine and human.Among the E coli strains examined by PCR,most resistant strains carried two mutations in gyrA and/or two mutations in parC.In ad-dition,some resistant strains had mutations in parE with MIC of ciprofloxacin>16μg/ml.No(resistance) mutation was found in gyrB.Seven strains(25.O%)and one strain(11.1%)had aac(6)-I b-cr,variant isolated from chicken and swine,respectively.The strains harboring cr variant enzyme reduced the suscepti-bility to ciprofloxacin and norfloxacin by N-acetylation of the drugs. Conclusion There is a close relation-ship between high level quinolone resistance and the numbers of amino acid exchange in DNA gyrase and to-poisomeraae IV,and aac(6)-I b-cr may play some role for fluoroquinolone resistance.

Antimicrobial resistant mechanisms analysis of outpatient Salmonella enterica serotype Typhimurium in Wuhan / 中华检验医学杂志

Objective To characterized the Salmonella enterica serotype typhimurium isolates recovered during 2002 to 2005 from outpatients in Tongji Hospital, Wuhan China. Methods The 36 isolates from Tongji Hospital were characterized by antimicrobial-susceptibility testing and screened for class Ⅰ integrons, beta-lactamase genes, qnr, aac(6')-Ib-cr and mutations in the quinolone resistance determining regions (QRDRs) by PCR and DNA sequence analysis. All isolates were also characterized by pulsed-fieldgel electrophoresis (PFGE) to determine the genetic relateness among these isolates. Results All isolates displayed multidrug resistance and most of them harbored class Ⅰ integrons. Ciprofloxacin-resistant isolates showed significant difference compared with ciprofloxacin-susceptible isolates after PFGE analysis. All 31 ciprofloxacin resistant isolates carried at least three mutations in the QRDR of GyrA and ParC. Three ciprofloxacin resistant isolates had accumulated additional mutation in ParE. Five isolates harboring the OXA-30. Enzyme showed intermediate resistant to eefepime. Conclusions Fluoroquinolone-resistant Salmonella typhimurium isolates were widely distributed among the outpatients in Wuhan and the resistant isolates accumulated multiple antimicrobial resistant mechanisms and showed unique genetic profiles. The state and local health authority must remain vigilant for the emergence of Salmonella typhimurium resistant to both third generation cephalosporins and fluoroquinolonos.