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 analyze the effect of altitude on NIH-CPSI score in patients with chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS)Methods:Clinical data and the results of NIH-CPSI Questionnaire of the 321 patients with CP/CPPS at different altitudes were collected from March 2021 to March 2022.And the influence of altitudes on NIH-CPSI score of CP/CPPS was analyzed.Result:The NIH-CPSI score of patients living at an altitude of 4 300 m was significantly higher than that of patients living at an altitude of 1 500 m and 2 200 m.The CP/CPPS patients who lived in the higher altitude had more severe symptoms of pain and urination as well as lower scores of life quality(P＜0.05).Conclusion:NIH-CPSI score increased significantly with higher alti-tude,indicating more severe symptoms and decreased quality of life in CP/CPPS patients.These findings highlight the need for man-agement strategies for specific heights in patients with CP/CPPS.

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.

Glaesserella parasuis is the causative agent of Gl?sser's disease in pigs.However,the pathogenic mechanisms underlying its virulence is not yet fully understood.The RuvB protein,a member of the AAA+superfamily,is implicated in various cellular processes,yet its specific role in the virulence of Glaesserella parasuis has not been fully characterized.In this study,we con-structed a RuvB gene deletion mutant,designated ΔRuvB,using the serotype 13 Glaesserella pa-rasuis strain ZJ1208 and a suicide plasmid-mediated natural transformation approach.To elucidate the functional role of the RuvB gene,we comprehensively evaluated the biological characteristics of the ΔRuvB strain through a series of assays,including growth kinetics,colony morphology,bac-terial staining,transmission electron microscopy(TEM),osmotic stress tolerance,high-tempera-ture tolerance,heat shock resistance,UV resistance,capsular polysaccharide quantification,serum bactericidal assays,and murine virulence experiments.Our findings revealed that the growth rate of ΔRuvB showed no significant difference compared to the parental strain.TEM revealed a notable increase in bacterial cell length;however,the number of outer membrane vesicles(OMVs)on the surface of ΔRuvB did not significantly increase.Notably,the ΔRuvB strain displayed a significant reduction in capsular polysaccharide production and serum resistance,as well as diminished toler-ance to UV radiation and high temperatures.Significant alterations were observed in its resistance to osmotic stress or oxidative stress.In the mouse toxicity challenge experiment,in com-parison with the parental strain ZJ1208,the mortality rate dropped by 20 percentage points,suggesting that the virulence of ΔRuvB has been weakened to some extent.Collectively,these results underscore the critical role of the RuvB gene in enhancing the environmental adaptability of Glaesserella parasuis.

Aim To study the protective effect of puer-arin(PR)on myocardial injury in diabetic mice and to explore the related mechanism.Methods Eight male C57BL/6J mice were randomly selected as the control group,and the remaining mice were randomly injected with streptozotocin(STZ)to construct a diabetes mod-el,and the mice that were successfully modeled were randomly divided into the model group,PR high,medi-um and low dose groups,pyroptosis inhibitor(NSA)group and pyroptosis inducer(Nigericin)group,which were administered continuously for 12 weeks.After the last dose,the serum and heart tissues of mice were taken to observe the changes of myocardium,the con-tents of lactate dehydrogenase(LDH)and creatine ki-nase isoenzyme(CK-MB)in the serum were detected,and the protein and mRNA expressions of pyroptosis-related factors(NLRP3,caspase-1,GSDMD,IL-18,IL-1β)in myocardial tissues of mice were detected.Re-sults Compared with the control group,the model group had swollen and twisted myocardial tissue,myo-cardial arrangement disorder,increased collagen fibers,increased content of LDH and CK-MB in serum,and significantly increased the expression of pyroxosis relat-ed factors in myocardial tissue(P＜0.05 or P＜0.01).Compared with the model group,the pathologi-cal changes of myocardial tissue in in the PR and NSA groups were significantly improved,the content of ser-um LDH and CK-MB was significantly reduced,and the expression of pyroxosis related factors in myocardial tis-sue was significantly inhibited(P＜0.05 or P＜0.01),while there was no significant change in the Nigericin group.Conclusions PR has a protective effect on myocardial injury in diabetic mice,and its mechanism may be related to the inhibition of the NL-RP3/caspase-1/GSDMD pyrosis signaling pathway.

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 compare the application effects of plankton multiplex polymerase chain reac-tion-capillary electrophoresis(PCR-CE),SYBR Green Ⅰ real-time quantitative PCR(qPCR)and microwave digestion-vacuum filtration-automated scanning electron microscopy(MD-VF-Auto SEM)in the diagnosis of drowning.Methods Lung,liver and kidney tissues from 212 drowned corpses and 30 non-drowned corpses were examined respectively by the three drowning-related plankton testing methods,and the detection rates of plankton in each tissue by three methods were compared.Results In drowned corpses,the total detection rates of PCR-CE,qPCR,and MD-VF-Auto SEM were 93.9%,96.2%,and 95.3%,respectively,with no statistically significant difference(P>0.05).The detection rate of lung tissue by MD-VF-Auto SEM(100%)was higher than those of PCR-CE and qPCR(P<0.05),and there was no significant difference in the detection rates of the three methods in liver or kidney tissues(P>0.05).In non-drowning corpses,a small number of diatoms(less than 10 cells/10 g)were detected by MD-VF-Auto SEM method,only in liver and kidney tissues,while the other two methods yielded negative results for all tissues.Conclusion All three methods have good efficacy in the examination of drowned corpses.The MD-VF-Auto SEM method directly observes diatom morpho-logical characteristics through scanning electron microscopy,and the qualitative and quantitative analy-ses are intuitive and accurate.It has great advantages in the examination of difficult degradation samples.The PCR-CE method and qPCR method have a low sample demand(0.5 g),are easy to operate and have short detection time(4-7 h).They are easy to be applied in the grassroots depart-ments and are suitable for the rapid determination of drowned corpses in routin cases.The combina-tion of the two DNA methods with the MD-VF-Auto SEM method can increase the detection rate of plankton,ensuring the reliability of examination results.This combined use is of significant importance in the application of drowning diagnosis.

The aim of this paper was to investigate the serotypes,virulence factors and drug resist-ance of clinical isolates of Pasteurella rnultocida of porcine origin in recent years.Morphological screening and polymerase chain reaction(PCR)were used to isolate and identify 119 isolates from nasal swabs and lung tissue samples sent from swine farms in Zhejiang Province from 2010 to 2024.The isolates of Pasteurella multocida were subjected to capsular polysaccharide serotyping,lipopolysaccharide serotyping,virulence factor detection and drug resistance analysis by PCR and Kirby-Bauer disc agar diffusion method(K-B).The results showed that there were 64 strains(53.7％)of A-type,54 strains(45.3％)of D-type and 1 strain(0.9％)of F-type among the capsu-lar polysaccharide serotypes,and 10 strains(8.4％)of L1-type,20 strains(16.8％)of L3-type,86 strains(72.2％)of L6-type,and 3 strains(2.6％)of undetermined type among the lipopolysaccha-ride serotypes.The amplification results of 10 virulence genes showed that the detection rate of virulence genes hgbA,higbB and fimA was over 86.0％,the detection rate of toxA was 8.4％,while the virulence gene tbpA was not detected.There were also differences in the distribution vir-ulence genes in different capsular polysaccharide serotypes.Virulence factor pfhA was detected in type A and F but not in type D.The detection rate of adhesin gene tadD in serotype A(92.2％)was significantly higher than that of type D(9.3％),and,on the contrary,the detection rate of ad-hesin gene hsf-l in serotype D(90.7％)was significantly higher than that of type A(20.3％).Drug resistance analysis revealed that Pasteurella multocida showed high susceptibility to antimi-crobial drugs such as amoxicillin,ampicillin,cephalosporins,doxycycline,fosfenicol and ciprofloxa-cin,and showed strong resistance to antimicrobial drugs such as lincomycin,cotrimoxazole,genta-micin and amikacin,and there were 54 multi-drug resistant strains(78.3％).In summary,capsular polysaccharide serotypes were dominated by type A and D,lipopolysaccharide serotypes were dom-inated by L6,the distribution of some virulence genes varied greatly among different serotypes,and the proportion of multi-resistant strains was high,which provide reference for the prevention and control of this disease.

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 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.