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Streptococcus pneumoniae is one of the most common bacterial pathogens of a wide range of community-acquired infections. It has been more and more recognized that this bacterium could also play a role as a cause of nosocomial infections. In this study, by retrospective analysis of the phenotypic resistance characteristics and genomic characteristics of 52 S. pneumoniae isolates in a hospital in Beijing, China, from 2018 to 2022, we explored the carriage of resistance genes and mutations in penicillin-binding proteins corresponding to the resistances, and identified the population diversity based on the prediction of serotypes and identification of sequence types (STs). The isolates displayed resistances to erythromycin (98%), tetracycline (96%), sulfonamide (72%) and penicillin G (42%). Among the 52 isolates, 41 displayed multiple-drug resistance. In total, 37 STs and 21 serotypes were identified, and the clonal complex 271 serogroup 19 was the most prevalent subtype. Only 24 isolates (46.2%) of 7 serotypes were covered by the 13-valent pneumococcal conjugate vaccination. The isolates showed high carriages of resistance genes, including tet(M) (100%) and erm(B) (98.1%); additionally, 32 isolates (61.5%) had mutations in penicillin-binding proteins. We also observed 11 healthcare-associated infections and 3 cases infected by different subtypes of isolates. We did not find nosocomial transmissions between the patients, and these cases might be associated with the asymptomatic colonization of S. pneumoniae in the human population. Our results called for further active surveillance of these subtypes, as well as the continuous optimization of the treatment protocols. [ABSTRACT FROM AUTHOR]

Background: Neuroblastoma is the most common extracranial solid tumor of childhood. The high rate of recurrence is associated with a low survival rate for patients with high-risk neuroblastoma. There is thus an urgent need to identify effective predictive biomarkers of disease recurrence.Methods: A total of 116 patients with high-risk neuroblastoma were recruited at Beijing Children's Hospital between February 2015 and December 2017. All patients received multidisciplinary treatment, were evaluated for the therapeutic response, and then initiated on maintenance treatment. Blood samples were collected at the beginning of maintenance treatment, every 3 months thereafter, and at the time of disease recurrence. Plasma levels of cell-free DNA (cfDNA) were quantified by qPCR. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the ability of plasma cfDNA concentration to predict recurrence.Results: Of the 116 patients, 36 (31.0%) developed recurrence during maintenance treatment. The median time to recurrence was 19.00, 9.00, and 8.00 months for patients who had achieved complete response (n = 6), partial response (n = 25), and stable disease (n = 5), respectively, after multidisciplinary treatment. The median plasma cfDNA concentration at the time of recurrence was significantly higher than the concentration in recurrence-free patients throughout maintenance treatment (29.34 ng/mL vs 10.32 ng/mL). Patients recorded a plasma cfDNA level ≥ 29 ng/mL an average of 0.55 months before diagnosis of disease recurrence. ROC analysis of the power of plasma cfDNA to distinguish between patients with or without recurrence yielded an area under the curve of 0.825, with optimal sensitivity and specificity of 80.6 and 71.3%, respectively, at a cfDNA level of 12.93 ng/mL.Conclusions: High plasma cfDNA concentration is a potential molecular marker to signal disease recurrence in patients with high-risk neuroblastoma. [ABSTRACT FROM AUTHOR]

Purpose: Community-associated Staphylococcus aureus (CA S. aureus) is the most common causative pathogen of the skin and soft tissue infections (SSTIs). This study aims to determine clonal distribution, virulence factors of CA S. aureus clinical isolates from purulent SSTIs in Beijing, China. Materials and methods: CA-S. aureus isolates were collected from 115 outpatients with purulent SSTIs from the department of dermatology from April 2015 to April 2017. Multilocus sequence typing and Staphylococcus cassette chromosome mec typing were performed to explore molecular characteristics. Phylogenetic analysis of 16S rRNA of dominant S. aureus isolates was performed using MEGA-X software. Virulence genes were detected by PCR, while biofilm formation was evaluated by a microtiter plate method. The antimicrobial susceptibility was tested by an automatic VITEK system. Results: Forty-four CA-S. aureus isolates identified from SSTIs contain 9 methicillin-resistant S. aureus (MRSA) isolates (20.4%) and 35 methicillin-susceptible S. aureus isolates (MSSA) (79.6%). The dominant sequence types (STs) were ST22 (40.9%) and clonal complex 59 (CC59; 77.8%) in Community-associated methicillin resistant methicillin-resistant S. aureus. 27.8% of ST22 isolates were homologous to the epidemic ST22 EMRSA-15 in Europe. The prevalence of virulence genes lukS/lukF, tst-1, etA, edinA, icaA, and icaD was 50%, 93.2%, 4.5%, 4.5%, 100%, and 100%, respectively. All CC59 isolates exhibited stronger biofilm-forming capability than ST22 clones. Among the MSSA subgroup, the poor biofilm producers had significantly higher sensitivity to sulfamethoxazole/Trimethoprim. Conclusion: The dominant epidemic clone PVL+ ST22 MSSA containing tst-1 occurs in Beijing, indicating that a PVL+ ST398 clone which was previously predominant in this district had been replaced by a new clone. [ABSTRACT FROM AUTHOR]

Abstract: To evaluate plasma cell‐free DNA (cfDNA) as a promising biomarker for neuroblastoma (NB) tumor burden. Seventy‐nine eligible patients with newly diagnosed NB were recruited from Beijing Children's Hospital between April 2016 and April 2017. Additionally, from September 2011 to June 2017, 79 patients with stable NB were evaluated with a median follow‐up time of 21 months. Approximately 2 mL of peripheral blood was drawn upon enrollment, and plasma cfDNA levels were measured via quantitative polymerase chain reaction (qPCR). Total cfDNA analysis was performed using the long interspersed nuclear element 1 (LINE‐1) 79 bp fragment, and DNA integrity was calculated by the ratio of the LINE‐1 300 bp fragment to the LINE‐1 79 bp fragment. A total of 79 NB patients with a median age of 36 months comprised the group of newly diagnosed NB patients. The main primary tumor site was the retroperitoneal and adrenal region (81%). Three or more metastatic sites were found in 17.7% of patients. Stable NB patients older than 18 months comprised 98.7% of the stable NB patients. Neuron‐specific enolase (NSE), lactate dehydrogenase (LDH), and cfDNA levels were dramatically increased in the newly diagnosed NB patients and significantly different from those in the stable NB patients. Moreover, the concentration of cfDNA was much higher in patients with larger tumors. By analyzing the area under the receiver operator characteristic (ROC) curve (AUC), the areas of total cfDNA, NSE, and LDH levels were 0.953, 0.929, and 0.906, respectively. The sensitivity and specificity data clarified that the level of circulating cfDNA in plasma can be considered as a reliable biomarker for describing tumor load in NB. The plasma cfDNA concentration was as good as the levels of LDH and NSE to discriminate the tumor burden in children with NB. [ABSTRACT FROM AUTHOR]

Long-term exposure to air pollution has been associated with increased lung cancer incidence and mortality. However, the short-term association between air pollution and lung cancer mortality (LCM) remains largely unknown. We collected daily data on particulate matter with diameter <2.5 μm (PM 2.5), particulate matter with diameter < 10 μm (PM 10), sulfur dioxide (SO 2), and ozone (O 3), and LCM in three of the biggest cities in China, i.e. Beijing, Chongqing, and Guangzhou, from 2013 to 2015. We first estimated city-specific relationships between air pollutants and LCM using time-series generalized linear models, adjusting for potential confounders. A classification and regression tree (CART) model was used to stratify LCM risk based on combinations of air pollutants and meteorological factors in each city. Then we pooled the city-specific associations using random-effects meta-analysis. Meta regression was used to explore if city-specific characteristics modified the air pollution-LCM association. Finally, we stratified the analyses by season, age, and sex. Over the entire period, the current-day concentrations of PM 2.5 and PM 10 in Chongqing and PM 2.5 , PM 10 , and SO 2 in Guangzhou were positively associated with LCM (Excess risk ranged from 0.72% (95% CI 0.27%–1.17%) to 6.06% (95% CI 0.76%–11.64%) with each 10 μg/m3 increment in different pollutants), but the association between current-day air pollution and LCM in Beijing was not significant (P > 0.05). When considering the environmental and weather factors simultaneously, current-day PM 2.5 , relative humidity, and PM 10 were the most important factors associated with LCM in Beijing, Chongqing, and Guangzhou, respectively. LCM risk related with daily PM 2.5 , PM 10 , and SO 2 significantly increased with the increasing annual mean temperature and humidity of the city, while LCM risk related with daily O 3 significantly increased with the increases of latitude, annual mean O 3 concentration, and socioeconomic level. After stratification, the current-day PM 2.5 , PM 10 , and O 3 during the warm season in Beijing and PM 2.5 , PM 10 , and SO 2 during the cool season in Chongqing and Guangzhou were positively associated with LCM (Excess risk ranged from 0.93% (95% CI 0.42%–1.45%) to 7.16% (95% CI 0.64%–14.09%) with each 10 μg/m3 increment in different pollutants). Male and the elderly lung cancer patients were more sensitive to the short-term effect of air pollution. Lung cancer patients should enhance protection measures against air pollution. More attentions should be paid for the high PM 2.5 , PM 10 , and O 3 during the warm season in Beijing, and high PM 2.5 , PM 10 , and SO 2 during the cool season in Chongqing and Guangzhou. • Short-term exposure to air pollution may increase the risk of lung cancer mortality. • The short-term associations between air pollutants and lung cancer mortality varied by city and season. • Daily air pollutants and weather factors had synergistic effects on daily lung cancer mortality. • Male and elder lung cancer patients were more susceptible to air pollution. [ABSTRACT FROM AUTHOR]