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 summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective To investigate the application effect of cold snare endoscopic mucosal resection(CS-EMR)in the treatment of 6 to 9 mm colorectal small polyps.Methods A total of 82 patients with small colonic polyps in our hospital from March 2022 to August 2023 were collected and divided into the observation group(45 cases received CS-EMR)and the control group[37 cases received hot snare endoscopic mucosal resection(HS-EMR)]according to different surgical methods.The clinical efficacy,polyp resection status,complete polyp resection rate,perioperative indicators and occurrence of complications were compared between the two groups.Results Follow-up for 1 month after operation,the effective rate of treatment in the observation group was higher than that in the control group(P<0.05).There was no statistically significant difference in the polyp resection status or perioperative indicators between the two groups(P>0.05).There was no statistically significant difference in the complete polyp resection rates of patients with different pathological types or total complete resection rate between the two groups(P>0.05).The incidence of delayed bleeding and endoscopic hemostasis rate in the observation group were lower than those in the control group(P<0.05).Conclusion The complete resection rate of 6～9 mm colorectal polyps through CS-EMR was comparable to that of HS-EMR,and CS-EMR has a better efficacy and lower risk of perioperative bleeding,along with higher safety.

The codon was optimized for the bovine nebovirus(BNeV)VP1 gene and the recombi-nant plasmid pFastBac-Dual-VP1 was constructed,and BNeV-VP1 virus-like particles(VLPs)were prepared using a baculovirus expression system,and identified by Western blot,indirect im-munofluorescence and electron microscopy.Successfully validated VLPs were mixed with MF59 adjuvant and CpG-ODG,and mice were immunised by intramuscular injection and evaluated for immunity effects.The results showed that the optimized CAI(codon adaptation index)of VP1 gene was 0.93 and the GC content was 60.4％.The constructed recombinant plasmid was trans-formed into DH10Bac for blue-white spot screening,and after successful verification,it was trans-fected into SF9 cells to obtain recombinant baculovirus Baculo-BNeV-VP1.BNeV virus-like parti-cles with diameters ranging from 35 to 40 nm were observed under the electron microscope,and both IFA and Western blot experiments proved that the target proteins were successfully ex-pressed and biologically active,and protein optimisation revealed that the highest protein expres-sion was found at the infectious dose MOI=0.5.Mice were immunized by intramuscular injection after 50 μg of VLPs were mixed with MF59 adjuvant and CpG-ODN.The results showed that the VLPs immunization group produced IgG antibodies 7 days after the first dose,and the antibody ti-ter increased gradually,reaching a maximum of 1∶102 400,and declined at 35 d,but still main-tained a high level;The blocking titer BT50 is up to 640,which can induce the production of BNeV VP1-specific blocking antibody in mice.In this study,the baculovirus expression system was used to express the VP1 protein of BNeV,and BNeV VLPs were successfully constructed,which could induce humoral immune response in mice,which provided a reference for the follow-up research of BNeV vaccine.

Codon optimization was performed for the M and HN genes of bovine parainfluenza virus type 3(BPIV3),and the recombinant shuttle plasmid Dual-M+HN was constructed.BPIV3 VLPs was prepared using the baculovirus expression system,and verified by Western blot,IFA and elec-tron microscopy.The successfully verified virus-like particle(VLPs)were mixed with MF59 adjuvant and CpG-ODN immunoenhancer to immunize mice by intramuscular-injection,and BPIV3 inactivated vaccine group and adjuvant control group were set up.The immune effect of BPIV3 VLPs was evaluated by monitoring mouse serum specific antibodies,neutralizing antibodies and hemagglutination inhibition antibodies.The results showed that the optimized codon adaptation in-dex(CAI)of the M and HN protein genes were 0.96 and 0.95,respectively,and the CG content reached 54.1％and 53.1％,respectively.The constructed recombinant plasmid was transformed in-to DHI0Bac for blue and white spot screening.The validated recombinant rod particles were trans-fected into Sf9 cells to obtain the rod-shaped virus pFastBac-M+HN.Under electron microscopy,BPIV3 VLPs with a diameter of approximately 180 nm were observed.IFA and Western blot ex-periments confirmed the successful expression and biological activity of the target protein.Through protein optimization,it was found that the protein expression was highest at an infection dose of MOI=5.After mixing 50 μg VLPs with MF59 adjuvant and CpG-ODN,mice were immunized by intramuscular injection.The results showed that the antibodies in the VLPs immunized group be-gan to rise at 2 weeks of the first immunization and reached their peak at 21 days of the second im-munization,with an average IgG antibody titer of 1∶40 228;The average titer of neutralizing anti-bodies is 1∶298;The titer of hemagglutination inhibition antibody is 1∶549,reaching the level of inactivated vaccine(P≥0.05),indicating that the VLPs prepared in this experiment can induce hu-moral immune response in the body.In summary,this study successfully prepared VLPs capable of self-assembly expression of BPIV3 HN and M proteins,and induced humoral immune response in mice,providing research basis for subsequent BPIV3 VLPs vaccine research.

Objective:To access the relation of aortic arch calcification (AoAC) volume based on parathyroid SPECT/CT imaging with hungry bone syndrome (HBS) in patients with renal secondary hyperparathyroidism (SHPT) after parathyroidectomy (PTX).Methods:From June 2015 to May 2024, the imaging and clinical data of 89 renal SHPT patients (52 males, 37 females, age: (51.5±10.3) years) who underwent parathyroid 99Tc m-methoxyisobutylisonitrile (MIBI) SPECT/CT in Affiliated Jiangyin Hospital of Nantong University were retrospectively analyzed. The AoAC volume was measured by Volume software of SPECT/CT system. The patients were divided into HBS group and non-HBS group, and the independent-sample t test, Mann-Whitney U test were used to compare differences of various indicators between the two groups. Logistic regression was used to analyze the influencing factors of HBS. Results:All 89 patients underwent PTX successfully, 50 patients (56.2%) were with HBS and 39 patients (43.8%) were not. The differences of age ((47.9±9.9) vs (56.1±9.0) years, t=-3.98, P<0.001), AoAC volume (0.36(0.02, 1.30) vs 1.57(0.37, 3.77)cm 3, Z=-3.17, P=0.002), preoperative alkaline phosphatase (ALP) (345.75(218.50, 632.50) vs (203.13±114.57)U/L, Z=-4.69, P<0.001), preoperative parathyroid hormone (147.85(109.83, 227.40) vs (135.58±51.14)pmol/L, Z=-2.34, P=0.019) and preoperative serum corrected calcium ((2.38±0.21) vs 2.54(2.39, 2.62)mmol/L, Z=-3.09, P=0.002) between HBS group and non-HBS group were significant. Logistic regression analysis showed that the AoAC volume ((odds ratio, OR)=0.628, 95% CI: 0.427-0.924, P=0.018), preoperative ALP ( OR=1.007, 95% CI: 1.002-1.012, P=0.010) and preoperative serum corrected calcium ( OR=0.041, 95% CI: 0.003-0.545, P=0.016) were independent risk factors for HBS. Conclusion:The AoAC volume measured by preoperative SPECT/CT can be used for an effective criteria of evaluating HBS in patients with renal SHPT after PTX, and AoAC volume may be one of independent risk factors for HBS.

Objective:To investigate the relationship of the number and morphological of parathyroid glands on 99Tc m-methoxyisobutylisonitrile (MIBI) SPECT/CT with hungry bone syndrome (HBS) in patients with renal secondary hyperparathyroidism (SHPT) after parathyroidectomy (PTX). Methods:Eighty renal SHPT patients (46 males, 34 females; age (50.3±11.0) years) who underwent PTX between January 2018 and June 2024 were retrospectively analyzed in Affiliated Jiangyin Hospital of Nantong University. The number of parathyroid glands detected on SPECT/CT, diameter of parathyroid gland and its volume were recorded and measured. Patients were divided into HBS group and non-HBS group. Independent-sample t test, Mann-Whitney U test and χ2 test were used to compare differences of various indicators between those 2 groups. Multivariate logistic regression was used to analyze influencing factors of HBS. Results:HBS group included 45 patients and the rest 35 patients belonged to non-HBS group. Age ( t=-3.61, P=0.001), preoperative alkaline phosphatase (ALP) ( Z=-4.65, P<0.001), preoperative parathyroid hormone ( Z=-2.34, P=0.019) and preoperative serum corrected calcium ( t=-2.71, P=0.008) were all significantly different between HBS group and non-HBS group. Patients with the number of parathyroid glands≥4 detected by SPECT/CT were more in HBS group than those in non-HBS group (82.2%(37/45) vs 51.4%(18/35); χ2=8.87, P=0.003), and the total volume of parathyroid glands (2.56(1.93, 4.44) vs 2.00(1.18, 2.94)cm 3;Z=-2.25, P=0.024) and the maximum diameter of parathyroid glands ((17.71±3.78) vs (15.87±3.91) mm; t=2.14, P=0.036) were significantly different between those 2 groups. Logistic regression analysis showed that preoperative ALP (odds ratio ( OR)=1.008, 95% CI: 1.002-1.014, P=0.015), preoperative serum corrected calcium ( OR=0.017, 95% CI: 0.000-0.869, P=0.042) and the number of parathyroid gland≥4 detected by SPECT/CT ( OR=4.156, 95% CI: 1.038-16.642, P=0.044) were independent influencing factors for HBS. The sensitivity of the number of parathyroid glands≥4 detected by SPECT/CT for diagnosing HBS was 82.2%(37/45). Conclusion:The number of parathyroid glands≥4 detected by SPECT/CT is an independent influencing factor for HBS, with high diagnostic sensitivity for HBS, thus having good clinical value.

Objective:To access the relation of aortic arch calcification (AoAC) volume based on parathyroid SPECT/CT imaging with hungry bone syndrome (HBS) in patients with renal secondary hyperparathyroidism (SHPT) after parathyroidectomy (PTX).Methods:From June 2015 to May 2024, the imaging and clinical data of 89 renal SHPT patients (52 males, 37 females, age: (51.5±10.3) years) who underwent parathyroid 99Tc m-methoxyisobutylisonitrile (MIBI) SPECT/CT in Affiliated Jiangyin Hospital of Nantong University were retrospectively analyzed. The AoAC volume was measured by Volume software of SPECT/CT system. The patients were divided into HBS group and non-HBS group, and the independent-sample t test, Mann-Whitney U test were used to compare differences of various indicators between the two groups. Logistic regression was used to analyze the influencing factors of HBS. Results:All 89 patients underwent PTX successfully, 50 patients (56.2%) were with HBS and 39 patients (43.8%) were not. The differences of age ((47.9±9.9) vs (56.1±9.0) years, t=-3.98, P<0.001), AoAC volume (0.36(0.02, 1.30) vs 1.57(0.37, 3.77)cm 3, Z=-3.17, P=0.002), preoperative alkaline phosphatase (ALP) (345.75(218.50, 632.50) vs (203.13±114.57)U/L, Z=-4.69, P<0.001), preoperative parathyroid hormone (147.85(109.83, 227.40) vs (135.58±51.14)pmol/L, Z=-2.34, P=0.019) and preoperative serum corrected calcium ((2.38±0.21) vs 2.54(2.39, 2.62)mmol/L, Z=-3.09, P=0.002) between HBS group and non-HBS group were significant. Logistic regression analysis showed that the AoAC volume ((odds ratio, OR)=0.628, 95% CI: 0.427-0.924, P=0.018), preoperative ALP ( OR=1.007, 95% CI: 1.002-1.012, P=0.010) and preoperative serum corrected calcium ( OR=0.041, 95% CI: 0.003-0.545, P=0.016) were independent risk factors for HBS. Conclusion:The AoAC volume measured by preoperative SPECT/CT can be used for an effective criteria of evaluating HBS in patients with renal SHPT after PTX, and AoAC volume may be one of independent risk factors for HBS.