Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective To explore the predictive value of combined serum soluble hemoglobin scavenger receptor 163(sCD163),hypersensitive C-reactive protein(hs-CRP),and procalcitonin(PCT)for stroke-associated pneumonia(SAP).Methods A total of 100 patients with acute ische-mic stroke admitted to the First Hospital of Zhangjiakou from October 2021 to January 2023 were se-lected as the study subjects.According to whether they developed SPA within 7 days of admission,they were divided into SAP group(n=64)and non-SAP group(n=36).Based on pneumonia se-verity index(PSI),patients in the SAP group were further divided into mild SAP group and severe SAP group.Enzyme-linked immunosorbent assay(ELISA)was used to detect the serum levels of sCD163,hs-CRP,and PCT.The clinical data of the patients were collected and compared.Pearson's method was used to analyze the correlation between the PSI score and the serum levels of sCD163,hs-CRP,and PCT in SAP patients.Multivariate Logistic regression analysis was employed to screen for factors influencing the occurrence of SAP.Receiver operating characteristic(ROC)curve analy-sis was used to evaluate the predictive efficacy of serum sCD163,hs-CRP,and PCT for the occur-rence of SAP.Results The proportion of patients with dysphagia and the National Institutes of Health Stroke Scale(NIHSS)score in the SAP group were significantly higher than those in the non-SAP group(P＜0.05).The serum levels of sCD163,hs-CRP,and PCT in the SAP group were significantly higher than those in the non-SAP group(P＜0.05).The serum levels of sCD163,hs-CRP,and PCT in the severe SAP group were significantly higher than those in the mild SAP group(P＜0.05).Pearson's correlation analysis showed that the PSI score was positively correlated with the serum levels of sCD163,hs-CRP and PCT in SAP patients(r=0.356,0.413,0.391,P＜0.001).Logistic regression analysis revealed that serum sCD163,hs-CRP,PCT,NIHSS score,and dysphagia were all influencing factors for the occurrence of SAP(P＜0.05).The areas under the curve(AUC)for predicting SAP using serum sCD163,hs-CRP,PCT and their combina-tion were 0.842,0.924,0.866 and 0.973,respectively,with sensitivities of 73.44％,84.37％,67.19％and 90.62％,and specificities of 88.89％,83.33％,97.22％and 94.44％,respectively.The predictive value of the combined detection was superior to that of the individual detection of ser-um sCD163,hs-CRP and PCT(P＜0.05).Conclusion The serum levels of sCD163,hs-CRP,and PCT are elevated in SAP patients,and their changes are closely related to the severity of the disease.The combined detection of these three indicators has a high value in predicting the occur-rence of SAP and may serve as auxiliary markers for predicting early SAP.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective:To investigate the prevalence of norovirus and the correlation between norovirus infection and stool traits and clinical symptoms in children with acute gastroenteritis during 2021-2022.Method:A total of 2 195 anal swab samples were collected from cases of acute gastroenteritis in Beijing Children 's Hospital Affiliated to Capital Medical University from January 2021 to December 2022. PCR fluorescent probe assay was performed to detect norovirus，the clinical information and test results were performed by statistical analysis. Results:The detection rate of norovirus was 19.09%（419/2 195）in 2 195 children. The detection rates of male and female were 17.80%（244/1 371）and 21.24%（175/824），respectively，with statistically significant differences between genders（ χ2=3.945, P<0.05）. The positivity rate of noroviruses was higher in aged 1 month to 3 years［29.09%（64/220）~40.69%（94/231）］，especially in 1 year［40.69%（94/231）］. The norovirus detection rate ranged from 2.44%（2/82）to 35.84%（62/173）in different months，with a high detection rate between January and March，higher in the winter and spring［28.36%（150/529），21.07%（146/693）］，showing a clear seasonal distribution.Clinical symptoms of both vomiting and diarrhea were significantly more common among norovirus positive than negative children，the difference was statistically significant（ χ2=57.29, P<0.05）. Conclusion:In the high incidence season of winter and spring，for infants and young children aged 1 month to 3 years with diarrhea accompanied by vomiting symptoms，especially those aged 1 year，it is recommended to undergo norovirus related testing in time. Early treatment and isolation measures should be taken for diagnosed children to reduce cross infection and prevent outbreaks.

Objective To detect the serum levels of CC chemokine receptor 2(CCR2)and C-reactive pro-tein(CRP)in stroke patients,and analyze their relationship with the severity of stroke associated pneumonia and their clinical significance.Methods A total of 78 patients with stroke associated pneumonia who were di-agnosed and treated in the hospital from October 2022 to February 2023 were collected as the study group,ac-cording to the severity of pneumonia,the study group was divided into mild group(31 cases),moderate group(29 cases),and severe group(18 cases),78 stroke patients who did not develop pneumonia were included into control group.Pearson method was applied to analyze the correlation between serum CCR2 and CRP levels in stroke associated pneumonia patients.Multivariate Logistic regression was applied to analyze the factors influ-encing the occurrence of stroke associated pneumonia.Receiver operating characteristic(ROC)curve was ap-plied to analyze the diagnostic value of serum CCR2 and CRP for stroke associated pneumonia.Results The National Institute of Health stroke scale(NIHSS)score,serum CCR2,and CRP levels in the study group were obviously higher than those in the control group(P<0.05).The levels of serum CCR2 and CRP increased with the aggravation of pneumonia(P<0.05).The levels of serum CCR2 and CRP in the study group were positively correlated(r=0.799,P<0.05).NIHSS score,CCR2,and CRP levels were risk factors for stroke associated pneumonia in stroke patients(P<0.05).The area under the curve(AUC)for the diagnosis of stroke associated pneumonia using serum CCR2 and CRP alone was 0.873 and 0.888,respectively,and the AUC for the combined detection of the two was 0.936,the combined detection of the two was superior to the individual detection of serum CCR2 and CRP(Zcombination-CCR2=1.987,Zcombination-CRP=1.832,P=0.041,0.047).Conclusion Serum CCR2 and CRP are closely related to the severity of stroke associated pneumonia,and their combined detection has high diagnostic value for stroke associated pneumonia.

Objective To investigate the diagnostic value of serum soluble fms-like tyrosine kinase 1(sFlt-1)and soluble differentiation cluster 14(sCD14)in stroke-associated pneumonia(SAP).Methods A total of 67 SAP patients admitted to the hospital from March 2022 to January 2023 were selected as the study group,and 50 stroke patients without pneumonia during the same period were selected as the control group.Enzyme-linked immunosorbent assay was used to measure serum sFlt-1 and sCD14 levels.Pearson correlation analysis was used to analyze the correlation between serum sFlt-1,sCD14 levels and clinical data.Multivariate Logistic regression was used to analyze the influencing factors of SAP in patients with stroke.Receiver operating char-acteristic(ROC)curve was used to analyze the diagnostic value of serum sFlt-1 and sCD14 levels in predicting SAP in patients with stroke.Results The serum levels of sFlt-1 and sCD14 in SAP patients were higher than those in stroke patients without pneumonia and stroke patients with pneumonia alone(P＜0.05).SAP in stroke patients was associated with age,atrial fibrillation,heart failure,aspiration,dysphagia,brain stem stroke,proton pump inhibitor use,fever,cough,dyspnea,low-density lipoprotein cholesterol,procalcitonin(PCT),C-reactive protein,white blood cell count,national institutes of health stroke scale(NIHSS)score,clinical pulmonary infection(CPIS)score(P＜0.05).Correlation analysis showed that serum sFlt-1 level was positively correlated with sCD14(r=0.439,P＜0.001),and serum sFlt-1 and sCD14 levels were positively correlated with NIHSS score and CPIS score(P＜0.05).Multivariate Logistic regression analysis showed that sFlt-1,sCD14,proton pump inhibitor use,PCT,dysphagia,and age were the influencing factors of SAP in stroke patients(P＜0.05).ROC curve results showed that the area under the curve of serum sFlt-1 and sCD14 combined to evaluate SAP in stroke patients was higher than that of single detection(ZsFlt-1-combined=2.194,P=0.028,ZscD14-combined=2.310,P=0.002).Conclusion The serum levels of sFlt-1 and sCD14 are in-creased in SAP patients,and the combination of the two has a good diagnostic value for predicting the occur-rence of SAP.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Background Cadmium (Cd) is a ubiquitous and toxic heavy metal that can accumulate in human body. Previous studies have shown that Cd exposure can induce neurotoxicity, but the underlying mechanism remains unclear. Objective To investigate the metabolic impacts of multiple doses of Cd on mouse neural stem cells (NSCs), and to explore the potential mechanism and biomarkers of its neurotoxicity. Methods The NSCs were obtained from the subventricular zone (SVZ) of 1-day-old neonatal C57BL/6 mice. The passage 3 (P3) NSCs were exposed to CdCl₂ at designed doses (0, 0.5, 1.0, and 1.5 μmol·L⁻¹). The cells were treated with seven replicates, of which one plate was for cell counting. After 24 h of exposure, the intracellular and extracellular metabolites were extracted respectively and then detected by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS). The orthogonal partial least-squares discriminant analysis (OPLS-DA) was applied to visualize the alterations of metabolomic profiles and to identify the differential metabolites (DMs) based on their variable importance for the projection (VIP) value >1 and P<0.05. The metabolite set enrichment analysis (MSEA) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were performed to recognize the significantly altered metabolite sets and pathways. The dose-response relationships were established and the potential biomarkers of Cd exposure were identified by 10% up-regulated or 10% down-regulated effective concentration (EC) of target metabolites. Results A total of 1201 metabolites were identified in the intracellular metabolomic samples and 1207 for the extracellular metabolomic samples. The intracellular and extracellular metabolome of Cd-treated NSCs were distinct from that of the control group, and the difference grew more distant as the Cd dosage increased. At 0.5, 1.0, and 1.5 μmol·L⁻¹ dosage of Cd, 87, 83, and 185 intracellular DMs and 161, 176, and 166 extracellular DMs were identified, respectively. Within the significantly changed metabolites among the four groups, 176 intracellular DMs and 167 extracellular DMs were identified. Both intracellular and extracellular DMs were enriched in multiple lipid metabolite sets. Intracellular DMs were mainly enriched in taurine and hypotaurine metabolism, glycerophospholipid metabolism, and glycerolipid metabolism pathways. Extracellular DMs changed by Cd were mainly enriched in glycerophospholipid metabolism, steroid hormone biosynthesis, and cysteine and methionine metabolism pathways. Among intracellular DMs, 125 metabolites were fitted with dose-response relationships, of which 108 metabolites showed linear changes with the increase of Cd dosage. And 134 metabolites were fitted with dose-response relationships among extracellular DMs, of which 86 metabolites showed linear changes. The intracellular DMs with low EC values were hypotaurine, ethanolamine, phosphatidylethanolamine, and galactose, while the extracellular DMs with low EC values were acetylcholine and 1,5-anhydrosorbitol. Conclusion Cd treatment can significantly alter the intracellular and extracellular metabolome of mouse NSCs in a dose-dependent manner. The neurotoxicity of Cd may be related to glycerophospholipid metabolism. Acetylcholine, ethanolamine, and phosphatidylethanolamine involved in glycerophospholipid metabolism pathway might be potential biomarkers of Cd-induced neurotoxicity.

Objective:To investigate the changes in epidemiological characteristics of common respiratory pathogens in children in Beijing during COVID-19 epidemic.Methods:A total of 9 728 serum samples were collected from cases of acute respiratory infections in Beijing Children′s Hospital from January 2020 to December 2020. Indirect immunofluorescence antibody test was performed to detect IgM antibodies against eight common respiratory pathogens and the test results were statistically analyzed. The eight common respiratory pathogens were influenza virus A (FluA), influenza virus B (FluB), respiratory syncytial virus (RSV), adenovirus (ADV), parainfluenza virus (PIV), Mycoplasma pneumoniae ( Mp), Chlamydia pneumoniae ( Cp) and Legionella pneumophila ( Lp). Results:The detection rate of respiratory pathogens in 9 728 cases was 41.71% (4 058/9 728) and respiratory viruses (FluA, FluB, RSV, ADV and PIV) accounted for 46.18%(2 343/5 074)of all detected pathogens. Mp, FluB and FluA accounted for 84.73%(4 299/5 074)of all detected pathogens, and the detection rates were 24.27% (2 361/9 728), 11.49% (1 118/9 728) and 8.43% (820/9 728), respectively. There were 846 cases positive for two kinds of pathogens, and the most common co-infection was Mp and FluB. The detection rates in male and female were 37.56% (2 089/5 562) and 47.26% (1 969/4 166), respectively. There were significant differences in the total detection rate and the positive rates of PIV and Mp between different sexes ( P<0.05). The detection rate in school-age children (6-12 years old) was the highest (52.26%, 1 535/2 937). The detection rates of respiratory pathogens in different months ranged from 30.12% (203/674) to 49.81% (268/538) with higher rates in autumn and winter [42.45% (1 304/3 072) and 43.29% (1 618/3 738)]. The detection rates of FluA and FluB were higher in summer [11.46% (195/1 701)] and winter [14.63% (547/3738)], respectively. Most of RSV infection occurred in summer [1.35% (23/1 701)], and Mp could be detected all year round, especially in winter and spring [27.21% (1 017/3 738) and 25.64% (312/1 217)]. The detection rate of respiratory pathogens in outpatient group was higher than that in inpatient group [46.48% (1 583/3 406) vs 39.15% (2 475/6 322)]. The detection rate in severe cases was 26.10% (71/272). The detection rates of total pathogens, FluB and Mp were higher in outpatients than in inpatients and the differences were statistically significant ( P<0.05). The detection rates of FluA, PIV and ADV were higher in inpatients than in outpatients and the differences were statistically significant ( P<0.05). The detection rates of total pathogens, FluB and Mp in mild cases were significantly higher than those in severe cases and the differences were statistically significant ( P<0.05). The detection rate of RSV in severe cases was significantly higher than that in mild cases and the difference was statistically significant ( P<0.05). Conclusions:The protective measures taken during the period of regular prevention and control of COVID-19 epidemic could better prevent the spread of respiratory viruses, having a certain impact on the population susceptible to respiratory pathogens and typical seasonal patterns, but had little effect on the prevention and control of Mp. New protective measures needed to be studied to prevent Mp infection in children during epidemical season.