Simple and accurate genomic classification model for distinguishing between human and pig Staphylococcus aureus.

Staphylococcus aureus (S. aureus) can cause various infections in humans and animals, contributing to high morbidity and mortality. To prevent and control cross-species transmission of S. aureus, it is necessary to understand the host-associated genetic variants. We performed a two-stage genome-wide association study (GWAS) including initial screening and further validation to compare genomic differences between human and pig S. aureus, aiming to identify host-associated determinants. Our multiple GWAS analyses found six consensus significant k-mers associated with host species, providing novel genetic evidence for distinguishing human from pig S. aureus. The best k-mer predictor achieved a high classification accuracy of 98.12% on its own and had extremely high resolution similar to the SNPs-based phylogeny, offering a very simple target for predicting the cross-species transmission risk of S. aureus. The final k-mer model revealed that 90% of S. aureus isolates from farm workers were predicted as livestock origin, suggesting a high risk of cross-species transmission. Bayesian inference revealed different cross-species transmission directions, with the human-to-pig transmission for ST5 and the pig-to-human transmission for ST398. Our findings provide a simple and accurate k-mer model for identifying and predicting the cross-species transmission risk of S. aureus.

Spatiotemporal patterns and socioeconomic determinants of pulmonary tuberculosis in Dongguan city, China, during 2011-2020: an ecological study.

OBJECTIVE: Pulmonary tuberculosis (PTB) is a critical challenge worldwide, particularly in China. This study aimed to explore the spatiotemporal transmission patterns and socioeconomic factors of PTB in Dongguan city, China. METHODS/DESIGN: An ecological study based on the reported new PTB cases between 2011 and 2020 was conducted in Dongguan city, China. The spatiotemporal analysis methods were used to explore the long-term trend, spatiotemporal transmission pattern and socioeconomic factors of PTB. MAIN OUTCOME MEASURES: The number of new PTB cases. PARTICIPANTS: We collected 35 756 new PTB cases, including 23 572 males and 12 184 females. RESULTS: The seasonal-trend decomposition indicated a significant downward trend for PTB with a significant peak in 2017 and 2018, and local spatial autocorrelation showed more and more high-high clusters in the central and north-central towns with high incidence. The multivariate spatial time series analysis revealed that the endemic component had a leading role in driving PTB transmission, with a high total effect value being 189.40 (95% CI: 171.65-207.15). A Bayesian spatiotemporal model revealed that PTB incidence is positively associated with the agricultural population ratio (relative risk (RR) =1.074), gender ratio (RR=1.104) and the number of beds in medical institutions (RR=1.028). CONCLUSIONS: These findings revealed potential spatiotemporal variability and spatial aggregation of PTB, so targeted preventive strategies should be made in different towns based on spatiotemporal transmission patterns and risk factors.

Genome-based model for differentiating between infection and carriage Staphylococcus aureus.

Staphylococcus aureus (S. aureus) is a clinically significant opportunistic pathogen, which can colonize multiple body sites in healthy individuals and cause various life-threatening diseases in both children and adults worldwide. The genetic backgrounds of S. aureus that cause infection versus asymptomatic carriage vary widely, but the potential genetic elements (k-mers) associated with S. aureus infection remain unknown, which leads to difficulties in differentiating infection isolates from harmless colonizers. Here, we address the disease-associated k-mers by using a comprehensive genome-wide association study (GWAS) to compare the genetic variation of S. aureus isolates from clinical infection sites (272 isolates) with nasal carriage (240 isolates). This study uncovers consensus evidence that certain k-mers are overrepresented in infection isolates compared with carriage isolates, indicating the presence of specific genetic elements associated with S. aureus infection. Moreover, the random forest (RF) model achieved a classification accuracy of 77% for predicting disease status (infection vs carriage), with 68% accuracy for a single highest-ranked k-mer, providing a simple target for identifying high-risk genotypes. Our findings suggest that the disease-causing S. aureus is a pathogenic subpopulation harboring unique genomic variation that promotes invasion and infection, providing novel targets for clinical interventions. IMPORTANCE: Defining the disease-causing isolates is the first step toward disease control. However, the disease-associated genetic elements of Staphylococcus aureus remain unknown, which leads to difficulties in differentiating infection isolates from harmless carriage isolates. Our comprehensive genome-wide association study (GWAS) found consensus evidence that certain genetic elements are overrepresented among infection isolates than carriage isolates, suggesting that the enrichment of disease-associated elements may promote infection. Notably, a single k-mer predictor achieved a high classification accuracy, which forms the basis for early diagnostics and interventions.

Disease-Associated Streptococcus pneumoniae Genetic Variation.

Streptococcus pneumoniae is an opportunistic pathogen that causes substantial illness and death among children worldwide. The genetic backgrounds of pneumococci that cause infection versus asymptomatic carriage vary substantially. To determine the evolutionary mechanisms of opportunistic pathogenicity, we conducted a genomic surveillance study in China. We collected 783 S. pneumoniae isolates from infected and asymptomatic children. By using a 2-stage genomewide association study process, we compared genomic differences between infection and carriage isolates to address genomic variation associated with pathogenicity. We identified 8 consensus k-mers associated with adherence, antimicrobial resistance, and immune modulation, which were unevenly distributed in the infection isolates. Classification accuracy of the best k-mer predictor for S. pneumoniae infection was good, giving a simple target for predicting pathogenic isolates. Our findings suggest that S. pneumoniae pathogenicity is complex and multifactorial, and we provide genetic evidence for precise targeted interventions.

[Screening of pathogenic molecular markers of Staphylococcus aureus in children based on whole genome sequencing technology]. / åŸºäºŽå ¨åŸºå› ç»„æµ‹åºæŠ€æœ¯ç­›é€‰å„¿ç«¥é‡‘é»„è‰²è‘¡è„çƒèŒçš„è‡´ç— ç›¸å ³åˆ†å­æ ‡å¿—ç‰©.

OBJECTIVES: To explore the molecular characteristics of Staphylococcus aureus (S. aureus) in children, and to compare the molecular characteristics of different types of strains (infection and colonization strains) so as to reveal pathogenic molecular markers of S. aureus. METHODS: A cross-sectional study design was used to conduct nasopharyngeal swab sampling from healthy children in the community and clinical samples from infected children in the hospital. Whole genome sequencing was used to detect antibiotic resistance genes and virulence genes. A random forest method to used to screen pathogenic markers. RESULTS: A total of 512 S. aureus strains were detected, including 272 infection strains and 240 colonization strains. For virulence genes, the carrying rates of enterotoxin genes (seb and sep), extracellular enzyme coding genes (splA, splB, splE and edinC), leukocytotoxin genes (lukD, lukE, lukF-PV and lukS-PV) and epidermal exfoliating genes (eta and etb) in infection strains were higher than those in colonization strains. But the carrying rates of enterotoxin genes (sec, sec3, seg, seh, sei, sel, sem, sen, seo and seu) were lower in infection strains than in colonization strains (P<0.05). For antibiotic resistance genes, the carrying rates of lnuA, lnuG, aadD, tetK and dfrG were significantly higher in infection strains than in colonization strains (P<0.05). The accuracy of cross-validation of the random forest model for screening pathogenic markers of S. aureus before and after screening was 69% and 68%, respectively, and the area under the curve was 0.75 and 0.70, respectively. The random forest model finally screened out 16 pathogenic markers (sem, etb, splE, sep, ser, mecA, lnuA, sea, blaZ, cat(pC233), blaTEm-1A, aph(3')-III, ermB, ermA, ant(9)-Ia and ant(6)-Ia). The top five variables in the variable importance ranking were sem (OR=0.40), etb (OR=3.95), splE (OR=1.68), sep (OR=3.97), and ser (OR=1.68). CONCLUSIONS: The random forest model can screen out pathogenic markers of S. aureus and exhibits a superior predictive performance, providing genetic evidence for tracing highly pathogenic S. aureus and conducting precise targeted interventions.

[Dose-response relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children]. / 幼儿园儿童年龄与肺炎链球菌疫苗覆盖率间的剂量-ååº”å ³ç³».

OBJECTIVES: To investigate the potential relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children, and to provide a basis for guiding vaccination and developing new protein vaccines. METHODS: The stratified cluster random sampling method was used to select 1 830 healthy children from six kindergartens in Shunde District, Foshan City, China, and nasopharyngeal swabs were collected for the isolation and identification of Streptococcus pneumoniae. The logistic regression model based on restricted cubic spline was used to analyze the dose-response relationship between age and Streptococcus pneumoniae vaccination coverage. RESULTS: The rate of nasal Streptococcus pneumoniae carriage was 22.46% (411/1 830) among the kindergarten children, with the predominant serotypes of 6B, 19F, 15A, 23A, 34, and 23F. The coverage rates of 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) were 53.0% and 57.9%, respectively, and there was a significant non-linear dose-response relationship between age and the coverage rates of PCV10 and PCV13 (P<0.05), with a higher coverage rate of PCV10 (88.0%) and PCV13 (91.1%) in the children aged 2 years. There was a significant non-linear dose-response relationship between age and the coverage rates of pilus islet 1 (PI-1) and pilus islet 2 (PI-2) (P<0.05), with a lower vaccination coverage rate for PI-1 (37.7%) and PI-2 (16.1%). The coverage rates of PI-1 (13.0%-58.5%) and PI-2 (6.0%-29.4%) were lower in all age groups. The virulence genes lytA (99.5%) and ply (99.0%) associated with candidate protein vaccines showed higher vaccination coverage rates. CONCLUSIONS: There is a significant non-linear dose-response relationship between the age of kindergarten children and the coverage rates of PCV10 and PCV13 serotypes, and kindergarten children aged 2 years have a relatively high coverage rate of PCV. The high prevalence of the virulence genes lytA and ply shows that they are expected to become candidate virulence factors for the development of a new generation of recombinant protein vaccines.

Pan-Genome-Wide Association Study of Serotype 19A Pneumococci Identifies Disease-Associated Genes.

Despite the widespread implementation of pneumococcal vaccines, hypervirulent Streptococcus pneumoniae serotype 19A is endemic worldwide. It is still unclear whether specific genetic elements contribute to complex pathogenicity of serotype 19A isolates. We performed a large-scale pan-genome-wide association study (pan-GWAS) of 1,292 serotype 19A isolates sampled from patients with invasive disease and asymptomatic carriers. To address the underlying disease-associated genotypes, a comprehensive analysis using three methods (Scoary, a linear mixed model, and random forest) was performed to compare disease and carriage isolates to identify genes consistently associated with disease phenotype. By using three pan-GWAS methods, we found consensus on statistically significant associations between genotypes and disease phenotypes (disease or carriage), with a subset of 30 consistently significant disease-associated genes. The results of functional annotation revealed that these disease-associated genes had diverse predicted functions, including those that participated in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. Our findings suggest the multifactorial pathogenicity nature of this hypervirulent serotype and provide important evidence for the design of novel protein-based vaccines to prevent and control pneumococcal disease. IMPORTANCE It is important to understand the genetic and pathogenic characteristics of S. pneumoniae serotype 19A, which may provide important information for the prevention and treatment of pneumococcal disease. This global large-sample pan-GWAS study has identified a subset of 30 consistently significant disease-associated genes that are involved in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. These findings suggest the multifactorial pathogenicity nature of hypervirulent S. pneumoniae serotype 19A isolates and provide implications for the design of novel protein-based vaccines.

Whole-genome sequencing analysis of Klebsiella aerogenes among men who have sex with men in Guangzhou, China.

Klebsiella aerogenes is a common infectious bacterium that poses a threat to human health. Nevertheless, there are limited data on the population structure, genetic diversity, and pathogenicity of K. aerogenes, especially among men who have sex with men (MSM). The present study aimed to clarify the sequence types (STs), clonal complexes (CCs), resistance genes, and virulence factors of popular strains. Multilocus sequence typing was used to describe the population structure of K. aerogenes. The Virulence Factor Database and Comprehensive Antibiotic Resistance Database were used to assess the virulence and resistance profiles. In this study, next-generation sequencing was performed on nasal swabs specimens collected in an HIV Voluntary Counseling Testing outpatient department in Guangzhou, China, from April to August 2019. The identification results showed that a total of 258 K. aerogenes isolates were collected from 911 participants. We found that the isolates were most resistant to furantoin (89.53%, 231/258) and ampicillin (89.15%, 230/258), followed by imipenem (24.81%, 64/258) and cefotaxime (18.22%, 47/258). The most common STs in carbapenem-resistant K. aerogenes were ST4, ST93, and ST14. The population has at least 14 CCs, including several novel ones identified in this study (CC11-CC16). The main mechanism of drug resistance genes was antibiotic efflux. Based on the presence of the iron carrier production genes irp and ybt, we identified two clusters according to virulence profiles. In cluster A, CC3 and CC4 carry the clb operator encoding the toxin. Increased monitoring is needed for the three main ST type strains carried by MSM. The main clone group CC4 has a large number of toxin genes, and it spreads among MSM. Caution is needed to prevent further spread of this clone group in this population. In sum, our results may provide a foundation for the development of new therapeutic and surveillance strategies for treating MSM.

Pharmacokinetics, safety, and bioequivalence of apixaban tablets in healthy Chinese subjects under fasting and fed conditions.

OBJECTIVE: To evaluate the pharmacokinetics (PK), safety, and bioequivalence of two formulations of apixaban in healthy Chinese subjects under fasting and fed conditions. MATERIALS AND METHODS: A single-center, randomized, open, single-dose, two-period crossover PK study was carried out under fasting and fed conditions in 64 healthy subjects enrolled in either the fasting (36 subjects) or the fed (28 subjects) arms of the study. Subjects received a single oral dose of 2.5 mg apixaban tablets as test (T) or reference (R) formulation. The primary PK parameters determined were the area under the plasma concentration-time curve from zero to t and ∞ (AUC0-t and AUC0-∞) and the maximal plasma concentration (Cmax). Safety was assessed mainly from the occurrence of adverse events (AEs). RESULTS: A single drop-out in the fed arm of the trial was excluded from the statistical evaluation. The 90% confidence intervals (CIs) for the geometric mean ratio (GMR) for T/R using AUC0-t were 95.4 - 100.9% and 97.8 - 103.8%, and for AUC0-∞ were 95.3 - 100.6% and 98.3 - 104.3% under fasting (36 subjects) and fed (27 subjects) conditions, respectively. Similarly, the 90% CIs for Cmax were 94.6 - 103.1% and 88.8 - 102.0% under fasting (36 subjects) and the fed (27 subjects) conditions, respectively. Therefore, the 90% CIs for the T/R AUC and Cmax ratios were within the standard range for bioequivalence (80.0 - 125.0%). There were no serious adverse events (SAEs). CONCLUSION: The test and reference 2.5 mg apixaban tablets were bioequivalent and both showed good tolerability and safety.

Evaluation of intervention effect of health education on overweight and obesity among middle school students in Guangzhou / 中国学校卫生

Objective@#To explore the effect of the comprehensive intervention on overweight and obesity among middle school students at the population level (health education lecture and official account push) and individual level (personalized dietary guidance), so as to provide a reference for preventing and controlling their overweight and obesity.@*Methods@#Three junior high schools and three senior high schools were randomly selected in Guangzhou in 2018 by convenience sampling. Through physical examination, 1 457 overweight and obese students aged from 12 to 18 years old were screened. Intervention was administered through "Student Personalized Dietary Guidance" manual, health tweets on the official accounts, and health education lectures from September 2018 to December 2019. The Chi square test was used to compare the difference in overweight and obesity constituent ratio between the two groups before and after the intervention. And intervention effect was evaluated by analyzing the number needed to treated(NTT).@*Results@#The proportion of overweight before the intervention was 66.71% (972/1 457), and decreased to 59.92% (873/1 457) after the intervention; the proportion of obesity before the intervention was 33.29% (485/1 457), which decreased to 26.63% (388/1 457) after the intervention. Among obese students, the smallest NNT was seen in the girl group aged 12-13 years (NNT=2.6, 95% CI =1.9-4.1), while the largest NNT in the boy group aged 14-18 years (NNT=5.9, 95% CI =4.7-8.1). The NNT of the girls aged 12-13 years was the smallest (NNT=2.7, 95% CI =2.2-3.5), and the NNT of the boys aged 14-18 years was the largest (NNT=7.4, 95% CI =6.0-9.7).@*Conclusion@#Health education at population level (health education lectures, official account push) with individual level (personalized dietary guidance) can effectively intervene overweight and obesity among middle school students in Guangzhou.

HIV-infected patients rarely develop invasive fungal diseases under good immune reconstitution after ART regardless high prevalence of pathogenic filamentous fungi carriage in nasopharynx/oropharynx.

Purpose: We aimed to investigate the prevalence and risk factors of filamentous fungi (FF) carriage in human immunodeficiency virus (HIV)-infected patients in Guangdong province, along with its subsequent incidence of invasive fungal disease (IFD). Methods: Seven hundred and sixteen HIV-infected individuals from the outpatient clinic and 293 sex-matched healthy controls were recruited prospectively from May 1 to August 31, 2017. Fungi were isolated from oropharyngeal and nasopharyngeal swabs, then identified by morphological and molecular biological techniques. Logistic regression analysis was used to identify risk factors of pathogenic FF carriage. Pathogenic FF carriers were followed up through the end of 2019. Results: Of the 716 included HIV-infected patients, 602 (84.1%) were male, the median age was 34 (27-42) years, and the median CD4+ count was 385 (254-542) cells/µl. Pathogenic FF were isolated in 119 (16.6%) cases with HIV infection and 40 (13.7%) healthy controls. Mucorales were found in 3 HIV-infected individuals and Talaromyces marneffei in 2 HIV-infected individuals, but not in healthy controls. History of cured opportunistic infections (OIs; OR, 1.97; 95% CI, 1.23-3.13, p = 0.004), and smoking (OR, 1.55; 95%CI, 1.03-2.32, p = 0.035) were independent risk factors of pathogenic FF carriage in HIV-infected individuals. A total of 119 pathogenic FF carriers with HIV infection were followed. During follow-up, 119 (100%) cases received antiretroviral therapy (ART) for at least 28 months, 107 (90%) cases had CD4+ counts>200 cells/µl, and none developed IFD. Discussion: Pathogenic FF carriage is common in HIV-infected individuals but may not develop IFD in those who achieved immune reconstitution. Smoking and cured OIs history increase the risk of pathogenic FF carriage. Smoking abstinence and ART adherence are especially important for these patients.

Co-carriage of Streptococcus pneumoniae and Moraxella catarrhalis among preschool children and its influencing factors. / å­¦é¾„å‰å„¿ç«¥è‚ºç‚Žé“¾çƒèŒå’Œå¡ä»–èŽ«æ‹‰èŒæºå¸¦çŠ¶æ€åŠå½±å“å› ç´ åˆ†æž.

OBJECTIVES: To investigate the carriage status of Streptococcus pneumoniae (S.pneumoniae) and Moraxella catarrhalis (M. catarrhalis) in preschool children and the influencing factors for the carriage status. METHODS: The stratified cluster sampling method was used to select 2 031 healthy children from seven kindergartens in Shunde District of Foshan in Guangdong, China. Nasal swabs were collected from all children for the isolation and identification of S. pneumoniae and M. catarrhalis. The carriage status of S. pneumoniae and M. catarrhalis was analyzed in terms of its association with demographic features and hospital- and community-related factors. RESULTS: The carriage rates of S. pneumoniae and M. catarrhalis were 21.81% and 52.44%, respectively among the children. The co-carriage rate of S. pneumoniae and M. catarrhalis was 14.87%. The correspondence analysis showed that the factors such as lower grade, non-local registered residence, living in rural areas, small living area, history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history were significantly associated with the co-carriage of S. pneumoniae and M. catarrhalis among the children (P<0.05). CONCLUSIONS: Co-carriage of S. pneumoniae and M. catarrhalis can be observed in preschool children. Young age, poor living environment, a history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history are important risk factors for the co-carriage of S. pneumoniae and M. catarrhalis in preschool children.

Spatiotemporal analysis of the morbidity of global Omicron from November 2021 to February 2022.

The Omicron variant was first reported to the World Health Organization (WHO) from South Africa on November 24, 2021; this variant is spreading rapidly worldwide. No study has conducted a spatiotemporal analysis of the morbidity of Omicron infection at the country level; hence, to explore the spatial transmission of the Omicron variant among the 220 countries worldwide, we aimed to the analyze its spatial autocorrelation and to conduct a multiple linear regression to investigate the underlying factors associated with the pandemic. This study was an ecological study. Data on the number of confirmed cases were extracted from the WHO website. The spatiotemporal characteristic was described in a thematic map. The Global Moran Index (Moran's I) was used to detect the spatial autocorrelation, while the local indicators of spatial association (LISA) were used to analyze the local spatial correlation characteristics. The joinpoint regression model was used to explore the change in the trend of the Omicron incidence over time. The association between the morbidity of Omicron and influencing factors were analyzed using multiple linear regression. This study was an ecological study. Data on the number of confirmed cases were extracted from the WHO website. The spatiotemporal characteristic was described in a thematic map. The Global Moran Index (Moran's I) was used to detect the spatial autocorrelation, while the LISA were used to analyze the local spatial correlation characteristics. The joinpoint regression model was used to explore the change in the trend of the Omicron incidence over time. The association between the morbidity of Omicron and influencing factors were analyzed using multiple linear regression. The value of Moran's I was positive (Moran's I = 0.061, Z-score = 3.772, p = 0.007), indicating a spatial correlation of the morbidity of Omicron at the country level. From November 26, 2021 to February 26, 2022; the morbidity showed obvious spatial clustering. Hotspot clustering was observed mostly in Europe (locations in High-High category: 24). Coldspot clustering was observed mostly in Africa and Asia (locations in Low-Low category: 32). The result of joinpoint regression showed an increasing trend from December 21, 2021 to January 26, 2022. Results of the multiple linear regression analysis demonstrated that the morbidity of Omicron was strongly positively correlated with income support (coefficient = 1.905, 95% confidence interval [CI]: 1.354-2.456, p < 0.001) and strongly negatively correlated with close public transport (coefficient = -1.591, 95% CI: -2.461 to -0.721, p = 0.001). Omicron outbreaks exhibited spatial clustering at the country level worldwide; the countries with higher disease morbidity could impact the other countries that are surrounded by and close to it. The locations with High-High clustering category, which referred to the countries with higher disease morbidity, were mainly observed in Europe, and its adjoining country also showed high spatial clustering. The morbidity of Omicron increased from December 21, 2021 to January 26, 2022. The higher morbidity of Omicron was associated with the economic and policy interventions implemented; hence, to deal with the epidemic, the prevention and control measures should be strengthened in all aspects.

Dose-Response Effects of Low-Dose Ionizing Radiation on Blood Parameters in Industrial Irradiation Workers.

While previous studies have focused on the health effects of occupational exposure of radiations on medical radiation workers, few have analyzed the dose-response relationship between low radiation doses and changes in blood parameters. Even fewer studies have been conducted on industrial worker populations. Using a prospective cohort study design, this study collected health examination reports and personal dose monitoring data from 705 industrial irradiation workers who underwent regular physical examinations at Dongguan Sixth People's Hospital. The dose-response effects of low-dose ionizing radiation on blood parameters were assessed using a generalized linear model and restricted cubic spline model. Red blood cell counts decreased then increased, before decreasing again with increasing ionizing radiation. This was in contrast to the curve of the total platelet count after irradiation. Additionally, a radiation dose of 2.904 mSv was the turning point for the nonlinear curve of hemoglobin count changes. In conclusion, long-term, low-dose ionizing radiation affects blood cell levels in industrial irradiation workers. There is a nonlinear dose-response relationship between red blood cell, platelet, and hemoglobin counts and the cumulative radiation dose. These findings should alert radiation workers to seek preventive medical treatment before the occurrence of any serious hematopoietic disease.

Solvent-Free Thermal Synthesis of Extra-Large-Pore Aluminophosphate Zeotype via Self-Assembly of Double-Four-Ring Unit.

The use of Ge as framework atom to direct the formation of double-four-ring (d4r) unit is an effective way to prepare zeolite with extra-large pores, which however also brings about serious problems with regard to production cost and structure stability for their practical application. A new solvent-free thermal synthesis strategy is presented here for facile preparation and molecular-level mechanism study of extra-large-pore aluminophosphate zeotype DNL-1 with -CLO structure. For the first time, the formation of intermediate d4r in the induction period was successfully confirmed, and was correlated with the synthesis condition of low water content and quaternary ammonium template with suitable alkyl chain length. The self-assembly pathway via d4r to form lta, afterwards clo and super cages was further revealed. This work shed light on the rational synthesis of Ge-free extra-large-pore zeotypes based on d4r route.

Association between maternal pre pregnancy and pre delivery overweight with overweight and obesity of middle school students:a case control study / 中国学校卫生

Objective@#To explore the association between maternal pre pregnancy and pre delivery overweight with overweight and obesity among offspring during adolescence in Guangzhou, and to provide evidence for child obesity prevention.@*Methods@#Based on the routine physical examination of primary and secondary school students in Guangzhou, random sampling was used to 6 middle schools and questionnaire survey was conducted among 3 384 students and their parents. Students with overweight and obesity were included in the case group, and the other students were included in the control group. Propensity Score Matching (PSM) was adopted to reduce selection bias. Logistic regression model and χ 2 test were used to analyze the data before and after PSM.@*Results@#The result of univariate analysis showed that there were statistically significant differences between overweight/obese group and the control group by gender, schooling stage (middle and high schools), picky eater, family history of obesity, family monthly income, delivery mode, high birthweight, and gestational weight gain before PSM( χ 2=42.38, 10.64, 14.47, 26.85, 10.58, 13.59 , 15.53, 20.64, P <0.05). After PSM, results showed that there were no statistically significant differences between overweight/obese group and the control group in middle and high schools, and mother delivery mode( P >0.05). Logistic regression analysis showed that the risk of overweight and obesity of maternal pre pregnancy on adolescent offspring was 1.54 times higher than control group (95% CI =1.01-2.36) before PSM, and the overweight and obesity of maternal predelivery also increased the risk of overweight and obesity of adolescent offspring( OR=2.35, 95%CI =1.67-3.31). After PSM, maternal overweight and obesity pre pregnancy ( OR=2.17, 95%CI =1.41-3.34) and maternal overweight and obesity pre delivery( OR=2.99, 95%CI =2.08-4.31) significantly increased the risk of overweight and obesity in adolescent offspring.@*Conclusion@#Maternal overweight and obesity pre pregnancy and pre delivery are associated with increased risk of overweight and obesity in adolescent offspring.

Transmission risk and resistance characteristics of Streptococcus pneumoniae among preschool children in Foshan / 中国学校卫生

Objective@#To understand the homology and resistance characteristics of Streptococcus pneumoniae (S. pneumoniae) in healthy preschool children, so as to provide basis for disease transmission prevention and rational use of antibiotics.@*Methods@#Stratified cluster random sampling method was used to sample 1 829 healthy children from six kindergartens in Shunde District, Foshan City. Nasal swabs were taken and tested for S. pneumoniae. Multi locus sequence typing was used for homology analysis. The Chi squared test and random forest analysis were used to explore the resistance characteristics.@*Results@#The nasal carriage rate of S. pneumoniae and multidrug resistant S. pneumoniae (MDRSP) in children were 22.5%(412/1 829) and 21.3%(390/1 829), respectively. Homology analysis in sequence types showed that the total homology rates of 6 kindergartens were 93.5%(87/93), 91.1% (72/79), 89.2%(58/65), 88.9%(64/72), 86.2%(50/58), 77.8%(35/45), respectively. It was found that the highest homology rate was 82.8% (48/58) within class and 93.1% (81/87) between classes. S. pneumoniae was mainly resistant to azithromycin (97.1%, 400/412), erythromycin (92.0%, 379/412) and tetracycline (91.5%, 377/412). The dominant multidrug resistance pattern of MDRSP isolates was not sensitive to azithromycin, erythromycin, cotrimoxazole, tetracycline and clindamycin. Random forest analysis indicated that the important phenotypic markers associated with MDRSP were resistance to azithromycin, cotrimoxazole, tetracycline, clindamycin and erythromycin(MDG=8.94, 6.92, 5.80, 4.84, 2.58).@*Conclusion@#The risk of cross transmission of S. pneumoniae among preschool children is high, and direct contact is the main way of transmission. Consequently, kindergartens and health departments should take effective measures to effectively prevent and block the spread of Streptococcus pneumoniae.

Methicillin-Resistant Coagulase-Negative Staphylococci Carriage is a Protective Factor of Methicillin-Resistant Staphylococcus Aureus Nasal Colonization in HIV-Infected Patients: A Cross-Sectional Study.

BACKGROUND: Methicillin-resistant coagulase-negative Staphylococci (MRCoNS) is regarded as the repository of mecA gene for methicillin-resistant Staphylococcus aureus (MRSA) and may develop methicillin-susceptible Staphylococcus aureus (MSSA) to MRSA. Therefore, we aimed to explore whether MRCoNS carriage is a risk factor of MRSA colonization. Phenotypic characteristics were performed to further assess the associations between MRSA and MRCoNS. METHODS: This cross-sectional study was conducted in Guangzhou, China. Participants completed a questionnaire and provided a nasal swab for further analysis. The risk factors of MRSA colonization were analyzed using nonconditional logistic regression models. The phenotypic characteristics between MRSA and MRCoNS were compared by Chi-square test. RESULTS: Among the 1001 HIV-infected patients, a total of 119 (11.89%) participants were positive for MRSA, and 34.45% (41/119) of all MRSA carriers were positive for MRCoNS. We found MRCoNS carriage was a protective factor of MRSA colonization (adjusted odds ratio = 0.59, 95% confidence interval: 0.38-0.91). A significant difference in the proportions of antibiotic resistance between MRSA and MRCoNS isolates was found except for penicillin, clindamycin, tetracycline, and teicoplanin. The main STs and CC types of MRSA isolates in this population were ST188 (15.1%) and CC59 (17.6%), respectively. CONCLUSIONS: HIV-infected patients remain a highly vulnerable population for MRSA colonization. Though who carried MRCoNS is less likely to have MRSA colonization, similarity of some antibiotic resistance between MRSA and MRCoNS was found in this study. Regular surveillance on the colonization and antibiotic patterns of MRSA and MRCoNS is still necessary.

Effects of exposure to low-dose ionizing radiation on changing platelets: a prospective cohort study.

BACKGROUND: Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers. METHODS: Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship. RESULTS: We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (Ptrend = 0.258), the non-linear trend tested was statistically significant (Pnon-linear = 0.007). Overall, there was a correlation between changing platelets and cumulative radiation dose (a change of ßa 0.008 × 109/L during biennially after adjusting for gender, age at baseline, service at baseline, occupation, medical level, and smoking habits; 95% confidence interval [CI] = 0.003,0.014 × 109/L). Moreover, we also found positive first and then negative dose-response relationships between cumulative radiation dose and changing platelets by restricted cubic spline models, while there were negative patterns of the baseline service not less than 10 years (- 0.015 × 109/L, 95% CI = - 0.024, - 0.007 × 109/L) and radiation nurses(- 0.033 × 109/L, 95% CI = - 0.049, - 0.016 × 109/L). CONCLUSION: We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.

Multidrug-resistant Staphylococcus aureus nasal carriage among HIV-positive outpatients in Guangzhou, China: Prevalence, risk factors, phenotypic and molecular characteristics.

INTRODUCTION: Data on comprehensive characterization of multidrug-resistant (MDR) Staphylococcus aureus (S. aureus) carriage in human immunodeficiency virus (HIV)-positive patients are limited. The objective of the present study is to determine the prevalence, risk factors, phenotypic and molecular characterization of MDR S. aureus isolated from HIV-positive population. METHODS: A cross-sectional study was conducted to determine the characteristics of MDR S. aureus nasal carriage among HIV-positive outpatients in an HIV clinic from June to August 2017. Nasal swabs and risk factor data of the enrolled HIV-positive outpatients were collected. Phenotypic and molecular characteristics of MDR and non-MDR S. aureus isolates were analyzed. Risk factors for nasal carriage with MDR S. aureus were estimated by logistic regression. The relationship between phenotypic and molecular characteristics of S. aureus isolates was assessed by the correspondence analysis. RESULTS: Overall, 1001 HIV-positive outpatients were included. The prevalence of MDR S. aureus nasal carriage was 15.18% (152/1001), and the proportion of multidrug resistance among S. aureus isolates was 60.08% (152/253). Having a history of respiratory tract infection was the risk factor for MDR S. aureus nasal carriage (adjusted odds ratio = 1.90, 95% confidence interval: 1.25-2.89). Multidrug resistance of S. aureus isolates was in good corresponding relationships with clonal complex (CC)5, CC15, CC59 and CC398. CONCLUSIONS: We found high burden of multidrug resistance among S. aureus isolated from HIV-positive outpatients, particularly in those who had upper respiratory tract infection. Moreover, CC59 and CC398 are highly related to multidrug resistance of S. aureus isolates.