Objective In order to understand the current resistance status of Aedes albopictus(Ae. albopictus) adult population to commonly used insecticides and the resistance dynamics development in Zhejiang Province and provide a theoretical basis for the scientific and rational use of hygienic insecticides. Methods Resistance determination was carried out using the diagnostic dose method(GB/T 26347-2010)recommended by WHO in the adult mosquito contact cylinder method to monitor the resistance of Ae. albopictus field populations in 11 cities and districts in Zhejiang Province in 2024. Results The monitoring result showed that adult Ae. albopictus in 11 areas were resistant or suspected resistant populations to both cis-cypermethrin and permethrin; suspected and resistant populations to the organophosphate insecticide malathion were as high as 81.82%; while suspected resistance to the carbamate insecticide residual carbofuran accounted for 45.45%, and the rest of the monitoring sites were sensitive to it. Conclusions The result suggest that the generalized resistance of Ae. albopictus populations to pyrethroids and organophosphorus insecticides in the field in Zhejiang Province needs to be highly emphasized. In future mosquito vector and mosquito-borne disease control, insecticides should be selected based on the resistance monitoring information, while following scientific guidelines for insecticide use.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective:To investigate the functional characteristics of the prefrontal cortex in patients with schizophrenia (SCZ) during resting state and analyze its association with clinical symptoms.Methods:Twenty-eight hospitalized patients with SCZ (SCZ group) were selected from November 2023 to May 2024, and 28 healthy controls (HC group) were recruited concurrently. By using functional near-infrared spectroscopy (fNIRS) technology, data on the concentration changes of oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) in the prefrontal cortex during resting state were collected from all subjects to measure cortical hemodynamic activity. Regional activation values and functional connectivity (FC) values among brain areas were analyzed. Clinical symptoms in patients were assessed using the positive and negative syndrome scale (PANSS).SPSS 25.0 software was employed for statistical analysis. Between-group comparisons were performed using independent samples t-tests or Mann-Whitney U tests. Spearman correlation analysis and general linear regression models were applied to examine relationships between prefrontal cortical functional characteristics and clinical symptoms. Results:The levels of HbO in the right inferior frontal gyrus and left frontal pole area were significantly higher in the SCZ group (1.5 (1.0, 3.0)μmol/L, 1.0 (1.0, 2.8)μmol/L) than those in the HC group (-0.01 (-0.05, 0.02)μmol/L, -0.02 (-0.07, 0.03)μmol/L) ( Z=-6.46, -6.50, both P<0.01). The levels of HbR in the bilateral dorsolateral prefrontal cortex were significantly higher in the SCZ group (0.02 (-0.01, 0.07)μmol/L, 0.01 (-0.01, 0.03)μmol/L) than those in the HC group (-0.01 (-0.03, 0.01)μmol/L, -0.01 (-0.02, 0.01)μmol/L) ( Z=-2.46, -1.98, both P<0.05).The SCZ group showed significantly higher HbO-based FC values in the frontal pole-temporal pole (0.49±0.21) and temporal pole-dorsolateral prefrontal cortex (0.36±0.25) compared to the HC group (0.33±0.18, 0.15±0.19) ( t=3.02, 3.44, both P<0.01). Conversely, the SCZ group exhibited significantly lower HbR-based FC in the frontal pole-inferior frontal gyrus (0.15±0.13) and inferior frontal gyrus-temporal pole (0.27±0.37) compared to the HC group (0.33±0.26, 0.77±0.48) ( t=-3.17, -4.23, both P<0.01). Correlation analysis revealed that in the SCZ group, the level of HbO in the right inferior frontal gyrus was positively correlated with negative symptoms, positive symptoms, excitement/hostility, and PANSS total score ( r=0.45-0.64, all P<0.05), and the level of HbO in the left frontal pole area was positively correlated with excitement/hostility and PANSS total score ( r=0.57, 0.50, both P<0.01), while the FC value between the frontal pole and temporal pole areas showed a negative correlation with excitement/hostility ( r=-0.39, P<0.05). Regression analysis demonstrated that, the HbO concentration in the right inferior frontal gyrus significantly positively predicted PANSS total score, positive symptoms, and negative symptoms ( β=0.70, 0.64, 0.55, all P<0.01).The HbO concentration in the left frontal pole area significantly positively predicted excitement/hostility ( β=0.77, P<0.01).The frontal pole-temporal pole HbO-based FC significantly negatively predicted excitement/hostility scores ( β=-0.42, P<0.01). Conclusion:Patients with SCZ exhibit hyperactivation of localized prefrontal cortex brain regions and dysfunction of functional connectivity during resting state, which are significantly associated with core clinical symptoms including positive, negative, and excitement/hostility symptoms.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To understand the pathogenic molecular characteristics of the latest prevalent Group A Streptococcus(GAS)in a suburban area of Beijing.Methods Throat swab specimens from children suspected of GAS infection in the outpatient setting of a sentinel surveillance hospital in a suburban area of Beijing from January 2023 to June 2025 were collected.GAS strains were detected and cultured.Antimicrobial susceptibility testing on 12 antimicrobial agents were performed,and molecular epidemiological characteristics of GAS strains was further ana-lyzed by whole genome sequencing technique.Results Data of 326 children suspected of GAS infection in outpatient setting were collected.A total of 41 GAS strains were detected and cultured,with a detection rate of 12.58％.The proportions of children with anterior cervical lymph node enlargement,tonsil congestion,and jaw congestion in the GAS positive group were all higher than those in the GAS negative group,and differences were all statistically sig-nificant(all P＜0.05).All 41 GAS strains carried both erm(B)and tet(M)resistance genes and exhibited a struc-tural type(cMLS)resistance phenotype.All of the emm12 strains were ST36,and emm1 strains were ST28.A to-tal of 6 emm12 subtypes and 1 emm1 subtype were detected,namely emm12.2,emm12.95,emm12.69,emm12.17,emm12.19,emm12.149,and emm1.12.Among them,emm12.149 was a newly discovered subtype.Nucleobase at the 175 100 locus in gene sequence had undergone an A→ T mutation.A total of 5 bacteriophages and 6 superanti-gens were detected.There were statistically significant differences in multi-nucleotide polymorphisms(MNPs)and insertion numbers in the genomes of emm12.0 and emm12 subtypes(both P＜0.05).The phylogenetic tree presen-ted a highly clonal group of 23 GAS strains in this area,accounting for 57.50％.Conclusion The prevalent GAS strain in this area is emm12.emm12.149 is a new subtype.The resistance genes and phenotypes are erm(B),tet(M),and structural type(cMLS).The genome has plenty genetic polymorphism,and the genome sequences of multiple GAS strains are highly cloned,indicating the possibility of clone transmission.This suggests that the sur-veillance of GAS in sentinel hospitals should continue to be strengthened,so as to provide theoretical basis for the prevention and control of GAS epidemics.

Objective:To investigate the functional characteristics of the prefrontal cortex in patients with schizophrenia (SCZ) during resting state and analyze its association with clinical symptoms.Methods:Twenty-eight hospitalized patients with SCZ (SCZ group) were selected from November 2023 to May 2024, and 28 healthy controls (HC group) were recruited concurrently. By using functional near-infrared spectroscopy (fNIRS) technology, data on the concentration changes of oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) in the prefrontal cortex during resting state were collected from all subjects to measure cortical hemodynamic activity. Regional activation values and functional connectivity (FC) values among brain areas were analyzed. Clinical symptoms in patients were assessed using the positive and negative syndrome scale (PANSS).SPSS 25.0 software was employed for statistical analysis. Between-group comparisons were performed using independent samples t-tests or Mann-Whitney U tests. Spearman correlation analysis and general linear regression models were applied to examine relationships between prefrontal cortical functional characteristics and clinical symptoms. Results:The levels of HbO in the right inferior frontal gyrus and left frontal pole area were significantly higher in the SCZ group (1.5 (1.0, 3.0)μmol/L, 1.0 (1.0, 2.8)μmol/L) than those in the HC group (-0.01 (-0.05, 0.02)μmol/L, -0.02 (-0.07, 0.03)μmol/L) ( Z=-6.46, -6.50, both P<0.01). The levels of HbR in the bilateral dorsolateral prefrontal cortex were significantly higher in the SCZ group (0.02 (-0.01, 0.07)μmol/L, 0.01 (-0.01, 0.03)μmol/L) than those in the HC group (-0.01 (-0.03, 0.01)μmol/L, -0.01 (-0.02, 0.01)μmol/L) ( Z=-2.46, -1.98, both P<0.05).The SCZ group showed significantly higher HbO-based FC values in the frontal pole-temporal pole (0.49±0.21) and temporal pole-dorsolateral prefrontal cortex (0.36±0.25) compared to the HC group (0.33±0.18, 0.15±0.19) ( t=3.02, 3.44, both P<0.01). Conversely, the SCZ group exhibited significantly lower HbR-based FC in the frontal pole-inferior frontal gyrus (0.15±0.13) and inferior frontal gyrus-temporal pole (0.27±0.37) compared to the HC group (0.33±0.26, 0.77±0.48) ( t=-3.17, -4.23, both P<0.01). Correlation analysis revealed that in the SCZ group, the level of HbO in the right inferior frontal gyrus was positively correlated with negative symptoms, positive symptoms, excitement/hostility, and PANSS total score ( r=0.45-0.64, all P<0.05), and the level of HbO in the left frontal pole area was positively correlated with excitement/hostility and PANSS total score ( r=0.57, 0.50, both P<0.01), while the FC value between the frontal pole and temporal pole areas showed a negative correlation with excitement/hostility ( r=-0.39, P<0.05). Regression analysis demonstrated that, the HbO concentration in the right inferior frontal gyrus significantly positively predicted PANSS total score, positive symptoms, and negative symptoms ( β=0.70, 0.64, 0.55, all P<0.01).The HbO concentration in the left frontal pole area significantly positively predicted excitement/hostility ( β=0.77, P<0.01).The frontal pole-temporal pole HbO-based FC significantly negatively predicted excitement/hostility scores ( β=-0.42, P<0.01). Conclusion:Patients with SCZ exhibit hyperactivation of localized prefrontal cortex brain regions and dysfunction of functional connectivity during resting state, which are significantly associated with core clinical symptoms including positive, negative, and excitement/hostility symptoms.