Background Group A streptococcus (GAS) could lead to various disease types in children, but central nervous system (CNS) infections are uncommon. In this paper, we analyzed the clinical features of a GAS case with meningitis and subdural empyema, and characterized the GAS clone. Case presentation A thirteen-year-old boy complained of fever, headache, and left hemiplegia. Physical examination also showed central facial palsy of left side. The examinations of blood and cloudy cerebrospinal fluid (CSF) showed bacterial meningitis. Blood cultures and metagenomic sequencing (mNGS) of CSF showed GAS, and GAS antigen of throat swab was positive. The first anti-streptolysin (ASO) was negative, but increased obviously after 2 weeks. The examination of emm type showed emm 12.0 isolate. The head MRI showed restricted diffusion in the right frontal lobe, subdural empyema in the right side of cerebral falx, and meningitis. The CT revealed rhinosinusitis and mastoiditis. Bacterial meningitis, subdural empyema, sepsis, and sinusitis were diagnosed, and vancomycin and ceftriaxone were given. The patient also received dexamethasone in the beginning. Gradual improvement was seen in the patient's clinical status, laboratory parameters (blood/CSF), and radiographic manifestations. Conclusions The contiguous spread from rhinosinusitis could lead to meningitis and intracranial abscess in adolescent. GAS infection could be the pathogen for subdural empyema in patients with an abrupt onset of symptoms and rapidly deteriorating clinical course.

Pneumococcal meningitis (PM) causes significant illness and death in children worldwide, especially in high-burden countries. This multicenter study aimed to examine the epidemiology, clinical symptoms, prognosis, strain serotyping, antibiotic resistance, and outcome-related factors in children with PM. A prospective surveillance study on children under 18 years old with laboratory-confirmed invasive pneumococcal disease (IPD) was conducted at 19 hospitals, mainly in tertiary pediatric hospitals, from 2019 to 2021. This period was early in the post-PCV13 era in China, when the vaccine had been licensed but coverage was still limited. Given the high morbidity associated with PM, we collected data on children diagnosed with PM between January 1, 2019, and December 31, 2021. We thoroughly analyzed their demographics, epidemiology, vaccination status, clinical characteristics, laboratory results, treatment, and prognosis. A total of 157 children participated in this study, with a median age of 30.4 (9.7, 53.7) months. Only three children had received the vaccination before admission. The most common season of onset was winter (37.6

Background: The epidemiological data of Streptococcus pneumoniae isolates are important for the practice of treatment and prevention. This research aimed to explore the epidemiological characteristics of pediatric S. pneumoniae isolated from outpatients and inpatients. Methods: S. pneumoniae were isolated from unsterile samples of inpatients and outpatients younger than five years old between March 2013 and February 2014. The serotypes were determined by diagnostic pneumococcal antisera, and resistance against 13 antibiotics was tested by either the E-test or the disc diffusion method. The sequence types (STs) were analyzed with multilocus sequence typing (MLST). Results: The five dominant serotypes obtained from inpatients were 19F(32.9%), 19A(20.7%), 23F(10.7%), 6A(10.0%), and 14 (8.6%), while those in the outpatients were 19F (13.6%), 23F (12.9%), 6A (10.0%), 6B (10.0%), and 19A (7.9%). The coverage rates of the 7-, 10- and 13-valent pneumococcal vaccine formulations were high. The non-susceptibility to penicillin, cefuroxime, imipenem, erythromycin, and trimethoprim-sulfamethoxazole among the inpatient isolates were 7.1%, 92.8%, 65.7%, 100%, and 85.0%, respectively, while those among the outpatient isolates were 0.7%, 50.0%, 38.6%, 96.4%, and 65.7%, respectively. There were 45 and 81 STs detected from the pneumococci isolated from inpatients and outpatients, respectively. CC271 was more prevalent in inpatients. Conclusions: The pneumococcal vaccine related serotypes were still prevalent either in inpatient department or in outpatient department, which with serious antibiotic resistance. These results might be helpful for understanding the epidemiology of S. pneumoniae in Beijing. PCVs can prevent vaccine related serotypes. Therefore, universal immunization of PCVs should be implemented to prevent the spread of vaccine related serotypes of S. pneumoniae .

Background:Staphylococcus aureus (S. aureus) was a prevalent pathogenic bacterium among children. Due to the extensive use of antibiotics, the sensitivity of S. aureus to these drugs has gradually declined. Since the 1960s, methicillin-resistant Staphylococcus aureus (MRSA) has emerged and spread worldwide, becoming a primary cause of both healthcare-associated (HA) and community-acquired (CA) infections. This retrospective study aimed to highlight the significance of S. aureus among bacteria isolated from children in Beijing, China, and to elucidate its antimicrobial resistance patterns. Methods:Data on all S. aureus infections from 2013 to 2022 were collected from the microbiology department of Beijing Children's Hospital. Only the first isolate from the same kind of specimen was analyzed. Antimicrobial susceptibility tests were carried out by Vitek 2 automated system (bio Mérieux, France) or Kirby-Bauer disc diffusion method, according to the guidelines recommended by the Clinical and Laboratory Standards Institute (CLSI). Results:During the decade-long research period, a total of 47,062 bacterial isolates were isolated from 433,081 submitted specimens, with 6477 of these isolates identified as S. aureus. The majority of patients with S. aureus infections belonged to the age group of infants under one-year-old, accounting for 37.9% of cases. S. aureus isolates were predominantly found in the Pneumology Department, and the most common source of these isolates was lower respiratory tract specimens, comprising 34.3% of the total. The resistance rates of S. aureus to penicillin and erythromycin were notably high, at 89.5% and 73.8%, respectively. In contrast, the resistance rates to linezolid, vancomycin, rifampicin, and moxifloxacin were remarkably low, at 0.0%, 0.0%, 1.3%, and 3.9%, respectively. The detection rate of MRSA was 27.8%. MRSA isolates were predominantly found in the newborn group, ICU, and sterile body fluids. Conclusion:In our study, the most prevalent specimen type was derived from the lower respiratory tract, whereas the highest positive rate was observed in ear secretions. These findings underscored the pressing necessity for ongoing antimicrobial resistance (AMR) surveillance and the revision of treatment guidelines, particularly given the elevated detection of MRSA in ICU wards, sterile body fluids, and the neonatal age group. MRSA exhibited significant resistance to all β-lactam antibiotics, erythromycin, and ciprofloxacin. Therefore, future research endeavors should prioritize examining specific antimicrobial resistance populations and potential intervention strategies, as these were vital in mitigating the dissemination of antimicrobial-resistant isolates.

This study aimed to provide data for the clinical features of invasive pneumococcal disease (IPD) and the molecular characteristics of Streptococcus pneumoniae isolates from paediatric patients in China. We conducted a multi-centre prospective study for IPD in 19 hospitals across China from January 2019 to December 2021. Data of demographic characteristics, risk factors for IPD, death, and disability was collected and analysed. Serotypes, antibiotic susceptibility, and multi-locus sequence typing (MLST) of pneumococcal isolates were also detected. A total of 478 IPD cases and 355 pneumococcal isolates were enrolled. Among the patients, 260 were male, and the median age was 35 months (interquartile range, 12-46 months). Septicaemia (37.7%), meningitis (32.4%), and pneumonia (27.8%) were common disease types, and 46 (9.6%) patients died from IPD. Thirty-four serotypes were detected, 19F (24.2%), 14 (17.7%), 23F (14.9%), 6B (10.4%) and 19A (9.6%) were common serotypes. Pneumococcal isolates were highly resistant to macrolides (98.3%), tetracycline (94.1%), and trimethoprim/sulfamethoxazole (70.7%). Non-sensitive rates of penicillin were 6.2% and 83.3% in non-meningitis and meningitis isolates. 19F-ST271, 19A-ST320 and 14-ST876 showed high resistance to antibiotics. This multi-centre study reports the clinical features of IPD and demonstrates serotype distribution and antibiotic resistance of pneumococcal isolates in Chinese children. There exists the potential to reduce IPD by improved uptake of pneumococcal vaccination, and continued surveillance is warranted.

心脏淀粉样变性是一种罕见的致死性疾病，由错误折叠的淀粉样蛋白沉积在心肌间质引起限制性心肌病。传统病理学诊断主要依靠刚果红特殊染色，近年来，随着免疫病理诊断技术及激光显微切割质谱联用技术在诊断心脏淀粉样变性中的推广应用，本病诊断和分型的准确性提高，为临床治疗提供了重要依据。本文就传统染色技术、免疫病理技术和激光显微切割质谱联用技术等在心脏淀粉样变性诊断中的研究进展及应用价值作一综述。

Introduction:Streptococcus pneumoniae (S. pneumoniae) is a major pathogen causing death in children. Few studies have evaluated the importance of S. pneumoniae in the identified bacteria in clinical work. This retrospective study aimed to reveal the rank of S. pneumoniae in determined bacteria isolated from children in Beijing, China, as well as the antimicrobial resistance of this pathogen.Methods:The number of specimen for bacterial culture and of bacterial species were cumulated and ranked based on the data of the two largest children's hospitals in Beijing from 2015 to 2021. The temporal change of S. pneumoniae culture, as well as the clinical data of S. pneumoniae isolates were collected and analyzed. The minimum inhibitory concentrations of antimicrobial agents were determined by BD Phoenix 100 automated system or Vitek 2 automated system for antimicrobial susceptibility testing. The breakpoints recommended by CLSI were adopted.Results:During the 7-year study period, a total of 45,631 bacterial isolates were cultured from 462,144 submitted specimens, in which S. pneumoniae was the third frequent agent following S. aureus and H. influenza, and accounting for 8.79% of the isolates (4011/45,631). In the 4011 S. pneumoniae isolates, 2239 and 997 ones were, respectively, isolated from sputum and bronchial lavage fluid. Most of S. pneumoniae strains were identified in winter (34.7%) and spring (26.1%), and were mainly isolated from patients under 5 years old (77.1%). Low susceptible rate (27.6%) of CSF isolates was determined to penicillin according to the parenteral meningitis breakpoints, while high susceptible rate (56.9%) of non-CSF isolates was obtained according to the parenteral non-meningitis breakpoints. The isolates showed low sensitivity to erythromycin and tetracycline (<5%). All isolates were susceptible to vancomycin and linezolid.Conclusion:The present results demonstrated that S. pneumoniae was one of the most commonly detected bacteria in current pediatric clinical tests, especially in young children under 5 years old, which emphasized the importance of prevention. Penicillin could still be the first empiric choice to treat non-meningitis pneumococcal infections, while erythromycin should not be involved in the treatment.

Objectives: This study firstly identified an IncHI5 plasmid pK254-KPC_NDM co-carrying two different class carbapenemase genes blaKPC-2 and blaNDM-1 in Klebsiella michiganensis K254.Methods: The strain K254 was sequenced by high-throughput genome sequencing. A detailed genomic and phenotypic characterization of pK254-KPC_NDM was performed.Results: pK254-KPC_NDM displayed the conserve IncHI5 backbone and carried a resistant accessory region: Tn 1696 -related transposon Tn 7414 containing blaKPC-2 and blaNDM-1 . A sequence comparison was applied to a collection of four Tn 1696 -related transposons (Tn 7414 -Tn 7417 ) harbouring carbapenemase genes. For all these four transposons, the bla NDM-1 was carried by Tn 125 derivatives within three different mobile genetic elements. Tn 7414 further acquired another carbapenemase gene, blaKPC-2 , because of the integration of the local blaKPC-2 genetic environment from Tn 6296 , resulting in the high-level carbapenem resistance of K. michiganensis K254. The conjugal transfer and plasmid stability experiments confirmed that pK254-KPC_NDM could be transferred intercellularly and keep the stable vertical inheritance in different bacteria, which would contribute to the further dissemination of multiple carbapenemase genes and enhance the adaption and survival of K. michiganensis under complex and diverse antimicrobial selection pressures.Conclusion: This study was the first to report the K. michiganensis isolate coharbouring blaKPC-2 and blaNDM-1 in the Tn 1696 -related transposon in IncHI5 plasmid. The emergence of novel transposons simultaneously carrying multiple carbapenemase genes might contribute to the further dissemination of high-level carbapenem resistance in the isolates of the hospital settings and pose new challenges for the treatment of nosocomial infection. (c) 2023 The Author(s).Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Public health threats posed by emerging respiratory infections are a significant concern, particularly in children and infants. Traditional culture-based detection methods are time-consuming and typically require 1-3 days. Herein, we developed and evaluated a 23-plex common respiratory pathogen mass spectrometry assay that enables the simultaneous detection of 18 common respiratory pathogens in children. This assay combines matrix-assisted laser desorption/ionization time of flight mass spectrometry with multiplex reverse transcription-PCR and targets 11 bacterial and 7 viral pathogens (including 10 subtypes), and two internal controls. The detection limit of the common respiratory pathogen mass spectrometry assay was as low as 1 copy/mu L, with no cross-reactivity with other organisms. We assessed the clinical performance of the common respiratory pathogen mass spectrometry assay using respiratory samples from 450 children. The total 450 clinical specimens underwent analysis via matrix-assisted laser desorption/ionization time of flight mass spectrometry, and the outcomes were juxtaposed with those derived from real-time reverse-transcriptase PCR conducted concurrently. The concordance between these methods was 96.0%, and the multiple infection identification rate was 7.1%. This innovative approach enables the simultaneous analysis of numerous outcomes from a solitary examination across 192 specimens within a timeframe of approximately 7 hours, with a dramatically reduced sample use and cost. In summary, the common respiratory pathogen mass spectrometry assay is a sensitive, accurate, and cost-effective method for detecting common respiratory pathogens in children and has the potential to revolutionize the diagnosis of respiratory tract infections. IMPORTANCE This study aimed to present and evaluate a novel co-detection method that enables the simultaneous identification of 11 bacterial and 7 viral pathogens in about 7 hours using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Our approach utilizes a combination of multiplex reverse transcription-PCR and matrix-assisted laser desorption/ionization time of flight mass spectrometry, which overcomes the limitations of conventional assays, which include a long assessment time, technical difficulty, and high costs. As a screening method for common respiratory pathogens in children, common respiratory pathogen mass spectrometry assay has the potential to revolutionize the diagnosis of respiratory tract infections by providing an accurate etiological diagnosis. The common respiratory pathogen mass spectrometry assay is expected to be a critical tool for the diagnosis of respiratory infections in children, offering a more efficient, cost-effective, and accurate approach for the detection of common respiratory pathogens.

原发性心脏恶性肿瘤较为罕见，预后差。早期诊断及治疗可以有效延长患者生存期。对于手术无法完全切除或已有远处转移的患者，靶向药物的使用是一种可行的辅助治疗手段。目前，此类疾病的分子特征及发病机制尚未明确。本文对常见的几种原发性心脏恶性肿瘤的分子病理学研究进展进行了综述。

Abstract Background Major depressive disorders is a chronic and severe psychiatric disorder with poor prognosis and quality of life. Abnormal erythrocyte fatty acid (FA) composition in depressed patients were found in our previous study, but the relationship between erythrocyte membrane FA levels and different severity of depressive and anxiety symptoms remains to be explored. Methods This cross-sectional study included 139 patients with first-diagnosed, drug-naïve depression and 55 healthy controls whose erythrocyte FA composition was analyzed. Patients with depression were divided into severe depression and mild to moderate depression or depression with severe anxiety and mild to moderate anxiety. Then the differences of FA levels among different groups were analyzed. Finally, the receiver operating characteristic curve analysis was applied to identify potential biomarkers in distinguishing the severity of depressive symptoms. Results Levels of erythrocyte membrane FAs were elevated among patients with severe depression compared with healthy controls or patients with mild to moderate depression of almost all kinds. While C18:1n9t (elaidic acid), C20:3n6 (eicosatrienoic acid), C20:4n6 (arachidonic acid), C22:5n3 (docosapentaenoic acid), total fatty acids (FAs), and total monounsaturated FAs were elevated in patients with severe anxiety compared with patients with mild to moderate anxiety. Furthermore, the level of arachidonic acid, C22:4n6 (docosatetraenoic acid), elaidic acid, and the combination of all 3 were associated with the severity of depressive symptoms. Conclusions The results suggested that erythrocyte membrane FA levels have the potential to be the biological indicator of clinical characteristics for depression, such as depressive symptoms and anxiety. In the future, more research is needed to explore the causal association between FA metabolism and depression.

Purpose:Bloodstream infections (BSIs) was an essential cause of morbidity and mortality in children. Empiric broad-spectrum treatment of BSIs may be costly and unable to effectively eliminate the correct pathogenic microbes, resulting in downstream antimicrobial resistance. The purpose was to provide evidence for diagnosis and treatment of bloodstream infections in pediatrics, by revealing the pathogen distribution and antibiotic resistance pattern of BSIs.Methods:In this 5-year study, a total of 2544 pathogenic bacteria stains, isolated from 2368 patients with BSI, were retrospectively analyzed, to define the species distribution and the antimicrobial resistance pattern in Beijing.Results:The most frequently isolated pathogenic bacteria were K. pneumoniae (12.1%), S. aureus (11.5%), E. coli (11.2%), and E. faecium (11.2%). Hematological malignancies were the most common disease among patients with underlying conditions. Methicillin resistance was detected in 30.0% of S. aureus and 81.7% of coagulase-negative Staphylococcus (CoNS), respectively. The detection rates of carbapenem-resistant-E. coli (CRECO) and carbapenem-resistant-K. pneumoniae (CRKPN) were 10.8% and 50.8%, respectively. In terms of 122 isolates of S. pneumonia, 5 isolates (4.1%) were penicillin-resistant Streptococcus pneumoniae (PRSP); meanwhile, 50 isolates (41.0%) were penicillin-intermediate Streptococcus pneumoniae (PISP). Among the non-fermentative gram-negative bacilli isolates, 22.8% and 26.9% of the P. aeruginosa, were resistant to imipenem and meropenem. Furthermore, the resistance rates of A. baumannii to imipenem and meropenem both were 54.5%.Conclusion:In the study, we demonstrated the characteristics of bloodstream infections and antimicrobial susceptibility pattern of pediatrics in Beijing. Gram positive bacteria were the main pathogens of BSIs. CoNS strains presented even higher resistance to multiple antibiotics, including methicillin, than S. aureus. K. pneumoniae and E. coli represent the most common isolated gram-negative bacteria and exhibited high resistance to a variety of antimicrobial agents. Therefore, it was of critical importance to implement appropriate antimicrobial medication according to pathogen distribution and drug susceptibility test.

Objective:To investigate the clinicopathological and molecular features of primary cardiac angiosarcoma (PCAS), and to analyze the correlation between KDR mutation and the clinicopathological features of PCAS.Methods:Thirteen cases of PCAS were collected at Beijing Anzhen Hospital, Capital Medical University from January 2007 to December 2021. The clinicopathological features, diagnosis, differential diagnosis and outcome were retrospectively analyzed. KDR mutation was detected by next-generation sequencing (NGS) and then the expression of KDR (VEGFR2) was determined by immunohistochemistry (IHC), with review of relevant literatures.Results:There were eight males and five females with a mean age of 45 years. The primary tumor was in the right atrium in 10 cases, left atrium in two cases and right ventricle in one case. The histomorphology was mainly poorly differentiated angiosarcoma (11 cases), with highly pleomorphic spindle or round cells in solid sheets, brisk mitotic activity and extensive necrosis. Vascular lumen formation was observed in two cases of high to moderate differentiation, and biphenotypic differentiation was seen in five cases. IHC staining showed CD34, CD31, Fli1, ERG and vimentin were diffusely positive, pan-cytokeratin was positive, Ki-67 index ranged from 3% to 90%, which was positively correlated with the differentiation degree and grade of the PCASs ( P<0.05). At the end of follow-up period, one patient was alive, two patients were lost to follow-up, and the remaining 10 patients had an average survival time of 4.6 months. Finally, NGS sequencing was performed on seven samples after screening, and the results showed that KDR and NF1 mutations were both present in three cases. VEGFR2 expression had no significant correlation with the differentiation degree and grade of PCAS ( P>0.05), and it was not related to KDR mutation. Conclusions:PCASs mainly occur in the right atrium, and are mainly poorly differentiated. Ki-67 index is helpful to assess the degree and grade of tumor differentiation. The occurrence and development of PCAS may be related to the pathway involved in KDR mutation, but KDR mutation has no clear correlation with clinicopathological characteristics of PCAS, and immunohistochemical staining can not replace gene detection to determine whether the tumor had KDR mutation.

Background: Since depression, sex hormones, and fatty acid status are interrelated, it is important to understand their relationships. In this study, we aimed to investigate sex differences in erythrocyte membrane fatty acid composition among first-diagnosed, drug-naïve patients with major depressive disorders.Methods: The study included 139 individuals with first-diagnosed, drug-naïve depression (male/female = 48/91) and 55 healthy controls (male/female = 24/31). The levels of erythrocyte membrane fatty acids were analyzed to compare the difference between males and females in both patients with depression and healthy controls, as well as to study their correlation with depressive symptoms.Results: In first-diagnosed, drug-naïve patients with major depressive disorders, sex disparities were observed in the levels of erythrocyte saturated fatty acids (SFAs) and n-6 PUFAs (such as C18:0, C20:4n6 and C22:4n6), where higher levels evident in females compared to in males. We found a noteworthy correlation between fatty acid levels and depressive symptoms, in which there is a significant association between female patients and depression but a weaker association between male patients and depression.Conclusion: Our findings demonstrate higher levels of n-6 PUFAs and SFAs in female patients with depression. The relationship between fatty acid composition and depressive symptoms was more prominent in females than males. These findings highlight the significance of considering sex as a crucial and interconnected factor in future investigations and potential adjunctive treatment for mood disorders by targeting fatty acid metabolism.

Objective To explore the feasibility of establishing a computer-aided diagnostic model of multi-stained pathological images in patients with non-inflammatory aortic medial degeneration(MD). Methods In this study, pathological sections of aortic surgical specimens for non-inflammatory lesions from patients with thoracic aortic aneurysms and dissections were retrospectively collected at the Beijing Anzhen Hospital, Capital Medical University from July to December 2018. The lesions were scanned under ×400 magnification as whole slide images(WSI) and then annotated by two pathologists. The annotated WSI images were randomly split into training and test sets in a 6:1 ratio. SE-EmbraceNet was used to train the data to construct a multi-classification model for MD of multi-stained pathology images, including intralamellar mucoid extracellular matrix accumulation (MEMA-I), translamellar mucoid extracellular matrix accumulation (MEMA-T), elastic fiber fragmentation and/or loss(EFFL) and smooth muscle cell nuclei loss (SMCNL). The classification effect of the model was evaluated based on the test set data, and the results were expressed in terms of accuracy, sensitivity, precision, and the F1 value. Results Totally 530 pathological slides of non-inflammatory aortic lesion surgical specimens from patients with aortic aneurysm and dissection were included. Extracted 5265 sets of images, each containing 5 stained pathological images of the same lesion site: HE staining, special staining (elastic fiber/VanGieson, Masson, Alcian blue/periodic acid Schiff) and smooth muscle actin staining. There were 4513 sets of training images, including 987 SMCNL, 2013 EFFL, 1337 MEMA-I, and 176 MEMA-T; and 752 test images including 166 SMCNL, 335 EFFL, 222 MEMA-I, and 29 MEMA-T. The overall performance of the model in the test set showed good results, with an accuracy of 96.54%(726/752). The model had the best classification performance for EFFL, with accuracy, sensitivity, precision, and F1 value all ≥98.51%. The model also had a great classification ability for SMCNL, with all evaluated indexes≥97.59%. Conclusion The multi-stained pathology image-based MD classification model constructed in this study has high classification accuracy and good generalization ability, which has the potential to be applied to assist in the diagnosis of the non-inflammatory aortic lesion.

Abstract Background To analyse clinical characteristics, antibiotic susceptibility, and risk factors for mortality in paediatric invasive pneumococcal disease (IPD) in Beijing. Methods Paediatric IPD patients in our hospital were retrospectively collected from 2012 to 2017. Clinical manifestations, laboratory tests, antimicrobial susceptibility and serotype of isolates, and risk factors for mortality of IPD were analysed. Results Overall, 186 IPD cases were enrolled. The major manifestations were meningitis (76), pneumonia with bacteraemia (60), bacteraemia without focus (21), and pneumonia with empyaema (22). Of 72 cases with underlying diseases, leukaemia (18.0%), congenital heart disease (15.3%), primary immunodeficiency disease (12.5%), nephrotic syndrome (12.5%), and cerebrospinal fluid leakage (12.5%) were most common. In total 96.9% of isolates would have been covered by the pneumococcal conjugate vaccine (PCV13), including 19F (32.8%), 19A (23.4%), 4 (17.2%), and 23F (9.4%). Nonsusceptibility rates of penicillin, cefotaxime, and cefepime among nonmeningitis patients increased between 2012 and 2017; The mortality rate was 21.5%. Meningitis, respiratory failure, multiple organ failure, and white blood cell count < 4000 cells/μL were independent risk factors for mortality. Conclusion Meningitis was the most common clinical manifestation of IPD, and was frequently associated with death. Strains in the PCV13 vaccine would cover most of the cases, and so wider use of PCV13 should be considered.

Background Some streptococci strains identified as Streptococcus pneumoniae (S. pneumoniae) by routine clinical methods exhibiting negative Quellung reaction results may belong to other species of viridans group streptococci or non-typeable S. pneumoniae. The purpose of this study was to investigate the identification and molecular characteristics of S. pneumoniae with negative Quellung reaction results. Methods One hundred and five isolates identified as S. pneumoniae using routine microbiological methods with negative Quellung reaction results were included. Multilocus sequence analysis (MLSA) was used as a gold standard in species identification, and the capacity of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) in identification was evaluated. Capsular genes and sequence types of S. pneumoniae isolates were determined by sequential multiplex PCR and multilocus sequence typing. Antimicrobial susceptibility patterns were determined via broth microdilution with a commercialized 96-well plate. Results Among the isolates, 81 were identified as S. pneumoniae and 24 were S. pseudopneumoniae by MLSA. MALDI-TOF MS misidentified six S. pneumoniae isolates as S. pseudopneumoniae and nine S. pseudopneumoniae isolates as S. pneumoniae or S. mitis/S. oralis. Thirty-one sequence types (STs) were detected for these 81 S. pneumoniae isolates, and the dominant ST was ST-bj12 (16, 19.8%). The non-susceptibility rates of S. pseudopneumoniae were comparable to those of NESp strains. Conclusions Some S. pneumoniae isolates identified by routine methods were S. pseudopneumoniae. Most NESp strains have a different genetic background compared with capsulated S. pneumoniae strains. The resistance patterns of S. pseudopneumoniae against common antibiotics were comparable to those of NESp.

Objective: To investigate the clinical, pathologic and radiologic features and molecular alterations in patients with primary cardiac leiomyosarcoma (PCLMS). Methods: Five cases of PCLMS were collected in Beijing Anzhen Hospital from January 2016 to December 2020. The clinical, pathologic and radiologic data, and molecular alterations were analyzed, and the patients were followed up. Results: All five patients were female, and had no history of leiomyosarcoma in other parts of the body. The age of patients ranged from 37 to 62 years (median 47 years). The main clinical symptoms were chest pain and dyspnea, one also presented with palpitation and lower limb weakness and one with dizziness. Two tumors were located in the left atrium, two in the right atrium, and one in the right ventricle, and they maximal diameter ranged from 2.5 to 14.0 cm (mean 6.2 cm). The neoplasms presented as medium-echo masses with a broad base in the echocardiography, and as a low-density, solid mass when detected by contrast-enhanced CT. Histologically, two tumors were well-differentiated and three were moderately and poorly differentiated, and two included extensive, loose myxoid stroma. Immunohistochemical staining showed that PCLMS was positive for SMA, desmin, MDM2, and epidermal growth factor receptor. Fluorescence in situ hybridization showed ALK gene rearrangement in two cases, and COL1A1-PDGFB fusion in three cases. All cases received surgical excision and two cases received chemotherapy. Three patients died within 0-11 months (mean survival of 7.7 months) and two patients were alive. Conclusions: PCLMS is a malignant tumor with a high recurrence rate and poor prognosis. These cases may provide useful information to improve the diagnosis and management of PCLMS.

Abstract Staphylococcus aureus is one of the most famous bacterial pathogens, it is a leading causative agent in skin and invasive infections. We analyzed the hemolytic patterns of MRSA isolates from Beijing Children’ hospital and found that most CC59 isolates were α hemolysis negative. In this study, we tried to find the possible reason for α hemolytic deletion in CC59 isolates. Hemolysis patterns of different MRSA types were showed. We have knocked out hlα gene of R23 isolate to form R23Δhlα isolate. A differential expression of hlα gene was examined among isolates with different hemolysis phenotypes using RT-PCR. We have examined the secretion of Hlα of R23, USA300 and R23Δhlα by Western blot. A high-copy-number plasmid containing the hlα gene was utilized to restore expression of α hemolysin.During the four periods (2009-2011, 2012-2013, 2016, 2017), 290 MRSA isolates were collected in Beijing Children’s Hospital (BCH). Most of the ST59 isolates (94.38%), and nine of the ST338 isolates (100%) showed negative α hemolysis phenotype. Both of them belong to CC30 clone. Transcriptional levels of hlα were equal among isolates showing α, δ hemolysis and β, δ hemolysis. R23 did not show α hemolysis phenotype but it produced Hlα. High-copy-number plasmid containing the hlα gene could restore α hemolysis phenotype of R23Δhlα isolate.This study elucidated that the negative α hemolysis in CC59 isolates was not related to Hlα protein production. However, over-production of Hlα could restore the α hemolytic activity. β hemolysin worked well in CC59 clone.