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 explore the clinical characteristics of Mycoplasma pneumoniae pneumonia(MPP)after COVID-19 epidemic so as to offer help for early clinical diagnosis and treatment.METHODS The clinical data that were collected from the MPP patients who were treated in the fever clinic of the First Medical Center of Chinese PLA General Hospital from Jul.2023 to Aug.2024 were retrospectively analyzed.The results of laboratory tests for the different age groups of patients complicated with other pathogens were statistically analyzed.RESULTS Of totally 161 MPP patients who were enrolled in the study,78(48.85％)were male,and 83(51.55％)were fe-male;the average age was(32.98±14.35)years old,and the patients aged between 20 and 40 years old accoun-ted for 43.48％(70 cases).The enrolled patients were divided into the simple MPP group with 92(57.14％)ca-ses and the MPP+mixed group with 69(42.86％)cases according to the result of etiological test of sputum;the patients of MPP+mixed group were divided into the MPP+bacteria group with 42(60.87％)cases,the MPP+fungi group with 10(14.49％)cases,and the MPP+viruses group with 17(24.64％)cases.There was significant difference in the age among the groups(P＜0.05);there were no significant differences in the sex,white blood cell counts and percentage of mononuclear cells among the groups,the percentage of lymphocytes was highest in the simple MPP group,the levels of C-reactive protein(CRP)and interleukin-6(IL-6)were highest in the MPP+bacteria group,and there were significant differences(P＜0.05).All of the patients were divided into three groups:the ≤20-year-old group the＞20-40-year old group and the＞40-year-old group.There were no sig-nificant differences in the white blood cell counts,percentage of lymphocytes,percentage of mononuclear cells and IL-6 level among the three groups,and the CRP level was highest in the＞20-40-year old group(P=0.025).Ran-dom forest model analysis showed that the weight of CRP was highest(22.65％)among the clinical characteristics of the MPP patients,which played a key role in construction of model.As for other factors,the weight of age was 17.02％,the percentage of lymphocytes 15.34％,the white blood cells counts 14.86％,the percentage of mono-nuclear cells 14.39％,the IL-6 13.61％,the gender 2.13％.CONCLUSION MPP maintains common among the patients aged less than 40 years old after the COVID-19 epidemic,nearly half of the patients are complicated with the infections of other pathogens,and CRP is more helpful for the clinical diagnosis and treatment of the MPP in early stage.

OBJECTIVE To summarize the clinical characteristics and diagnosis and treatment experiences in dealing with non-severe Chlamydia psittaci pneumonia.METHODS The clinical data were collected from 34 patients who were diagnosed with non-severe C.psittaci pneumonia through quantitative polymerase chain reactiong(qPCR)for sputum in fever clinic of the First Medical Center of Chinese PLA General Hospital from Mar.2023 to Mar.2024 and were retrospectively analyzed.The clinical characteristics and treatment outcomes were evaluated.RESULTS The average age of the patients was(44.82±13.74)years old,the ratio of male to female was 1∶1.83;all of the patients had fever;major symptoms were cough(70.59％),pharyngodynia(44.12％),and flu-like symptoms(41.18％);82.35％of the patients had the history of contact with poultry.The C-reactive pro-tein(CRP)level,interleukin-6(IL-6),systemic inflammatory response index(SIRI)and aggregate index of sys-temic inflammation(AISI)were higher among the patients aged no less than 44 years old than among the patients less than 44 years old(P＜0.05);the percentage of lymphocytes of the patients aged no less than 44 years old was lower than that of the patients aged less than 44 years old(P＜0.05).As for the imaging findings,73.53％of the patients had consolidation shadows,26.47％had ground-glass opacities,and 32.35％involved both lungs.All of the patients received quinolones or tetracyclines for treatment of 7-14 days and all symptoms relieved.CT reexami-nated 1 month after the treatment showed that 55.88％of the cases had complete absorption of pulmonary infec-tious lesions,and 35.29％had partial absorption.CONCLUSIONS The patients with non-severe Chlamydia psitta-ci pneumonia are characterized by the history of contact with poultry,fever complicated with respiratory tract symptoms,rise of inflammatory markers(more significant among patients of advanced age)and lower lobe con-solidation shadow/ground-glass opacities.Early identification and standardized treatment may facilitate the favora-ble treatment outcomes.

OBJECTIVE To explore the clinical characteristics of Mycoplasma pneumoniae pneumonia(MPP)after COVID-19 epidemic so as to offer help for early clinical diagnosis and treatment.METHODS The clinical data that were collected from the MPP patients who were treated in the fever clinic of the First Medical Center of Chinese PLA General Hospital from Jul.2023 to Aug.2024 were retrospectively analyzed.The results of laboratory tests for the different age groups of patients complicated with other pathogens were statistically analyzed.RESULTS Of totally 161 MPP patients who were enrolled in the study,78(48.85％)were male,and 83(51.55％)were fe-male;the average age was(32.98±14.35)years old,and the patients aged between 20 and 40 years old accoun-ted for 43.48％(70 cases).The enrolled patients were divided into the simple MPP group with 92(57.14％)ca-ses and the MPP+mixed group with 69(42.86％)cases according to the result of etiological test of sputum;the patients of MPP+mixed group were divided into the MPP+bacteria group with 42(60.87％)cases,the MPP+fungi group with 10(14.49％)cases,and the MPP+viruses group with 17(24.64％)cases.There was significant difference in the age among the groups(P＜0.05);there were no significant differences in the sex,white blood cell counts and percentage of mononuclear cells among the groups,the percentage of lymphocytes was highest in the simple MPP group,the levels of C-reactive protein(CRP)and interleukin-6(IL-6)were highest in the MPP+bacteria group,and there were significant differences(P＜0.05).All of the patients were divided into three groups:the ≤20-year-old group the＞20-40-year old group and the＞40-year-old group.There were no sig-nificant differences in the white blood cell counts,percentage of lymphocytes,percentage of mononuclear cells and IL-6 level among the three groups,and the CRP level was highest in the＞20-40-year old group(P=0.025).Ran-dom forest model analysis showed that the weight of CRP was highest(22.65％)among the clinical characteristics of the MPP patients,which played a key role in construction of model.As for other factors,the weight of age was 17.02％,the percentage of lymphocytes 15.34％,the white blood cells counts 14.86％,the percentage of mono-nuclear cells 14.39％,the IL-6 13.61％,the gender 2.13％.CONCLUSION MPP maintains common among the patients aged less than 40 years old after the COVID-19 epidemic,nearly half of the patients are complicated with the infections of other pathogens,and CRP is more helpful for the clinical diagnosis and treatment of the MPP in early stage.

OBJECTIVE To summarize the clinical characteristics and diagnosis and treatment experiences in dealing with non-severe Chlamydia psittaci pneumonia.METHODS The clinical data were collected from 34 patients who were diagnosed with non-severe C.psittaci pneumonia through quantitative polymerase chain reactiong(qPCR)for sputum in fever clinic of the First Medical Center of Chinese PLA General Hospital from Mar.2023 to Mar.2024 and were retrospectively analyzed.The clinical characteristics and treatment outcomes were evaluated.RESULTS The average age of the patients was(44.82±13.74)years old,the ratio of male to female was 1∶1.83;all of the patients had fever;major symptoms were cough(70.59％),pharyngodynia(44.12％),and flu-like symptoms(41.18％);82.35％of the patients had the history of contact with poultry.The C-reactive pro-tein(CRP)level,interleukin-6(IL-6),systemic inflammatory response index(SIRI)and aggregate index of sys-temic inflammation(AISI)were higher among the patients aged no less than 44 years old than among the patients less than 44 years old(P＜0.05);the percentage of lymphocytes of the patients aged no less than 44 years old was lower than that of the patients aged less than 44 years old(P＜0.05).As for the imaging findings,73.53％of the patients had consolidation shadows,26.47％had ground-glass opacities,and 32.35％involved both lungs.All of the patients received quinolones or tetracyclines for treatment of 7-14 days and all symptoms relieved.CT reexami-nated 1 month after the treatment showed that 55.88％of the cases had complete absorption of pulmonary infec-tious lesions,and 35.29％had partial absorption.CONCLUSIONS The patients with non-severe Chlamydia psitta-ci pneumonia are characterized by the history of contact with poultry,fever complicated with respiratory tract symptoms,rise of inflammatory markers(more significant among patients of advanced age)and lower lobe con-solidation shadow/ground-glass opacities.Early identification and standardized treatment may facilitate the favora-ble treatment outcomes.

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 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.