Objective:To investigate the clinical distribution characteristics changes in antimicrobial resistance, and carbapenemase resistance genes of Klebsiella pneumoniae isolated from children in Chongqing region during the period of January 2019 to December 2024, providing a basis for the rational use of antibiotics and the prevention and control of nosocomial infections.Methods:An observational study was conducted to retrospectively analyze 5 020 Klebsiella pneumoniae (KP) isolates detected in four hospitals of the Southwest Pediatric Laboratory Specialty Alliance. Antimicrobial susceptibility testing was performed by the minimum inhibitory concentration method combined with the disk diffusion method. Results were interpreted according to the 2024 Clinical and Laboratory Standards Institute (CLSI) standards. Carbapenemase resistance genes were detected by polymerase chain reaction (PCR) combined with Sanger sequencing. WHONET 5.6 was used for resistance analysis and SPSS 19.0 for statistical analysis. The chi-square test was used to assess trends in resistance rates, ESBL detection rates, and resistance rates of different CRKP carbapenemase genotypes from 2019 to 2024. Statistical significance was confirmed if the two-tailed P-value was <0.05. Results:A total of 5 020 strains were isolated, with a detection rate of 5.1% (5 020/99 063). The majority were from sputum (59.2%, 2 970/5 020), followed by pus (17.1%, 857), urine (9.7%, 487), venous blood (6.5%, 326), secretions (2.6%, 130), and other specimens (5.0%, 250).The lowest resistance rate was to amikacin (3.8%), followed by levofloxacin (10.9%), imipenem (19.1%), and meropenem (19.9%). Resistance rates to cefoperazone/sulbactam ( χ2=9.982 0, P=0.001 6), piperacillin/tazobactam ( χ2=10.110 0, P=0.001 5), ceftazidime ( χ2=3.849 0, P=0.049 8), cefotaxime ( χ2=7.605 0, P=0.005 8), cefepime ( χ2=13.510 0, P=0.000 2), aztreonam ( χ2=6.457 0, P=0.011 1), imipenem ( χ2=4.672 0, P=0.030 7), and levofloxacin ( χ2=7.555 0, P=0.006 0) showed an annual increasing trend. The main carbapenemase genes were blaNDM-5 (42.2%, 127/301), blaNDM-1 (33.9%, 102/301), and blaKPC-2 (17.3%, 52/301). Patients with KPC-2-producing strains (median age, 240 days) were older than those with NDM-1/NDM-5-producing strains (median age, 40 days) ( χ2=22.620 0, P<0.000 1). In neonatal wards, the detection rate of NDM-KP was higher than that of KPC-KP (64.6%, 148/229 vs. 26.9%, 14/52, χ2=24.680 0, P<0.000 1), whereas in ICUs, it was lower (6.1%, 14/229 vs. 26.9%, 14/52, χ2=20.450 0, P<0.000 1). Conclusion:In Chongqing region, the isolation rate of K. pneumoniae from sputum was the highest with most cases from neonatal wards. Resistance to carbapenems showed an upward trend. BlaNDM-5 was the predominant genotype in pediatric CRKP. Patients with KPC-KP were older than those with NDM-KP. NDM-KP predominated in neonatal wards, while KPC-KP predominated in ICUs, with KPC-KP showing higher antimicrobial resistance.

OBJECTIVE To investigate the distribution and drug resistance of the pathogens isolated from sterile body fluids in a hospital so as to provide reference for clinical treatment of the infections.METHODS The sterile body fluids specimens that were cultured positive for pathogens were retrospectively collected from a three-A hos-pital of Jiangxi Province between 2016 and 2023.The distribution and drug resistance of the isolated pathogens were observed.RESULTS Totally 16,658 strains of pathogens were isolated from the sterile body fluid speci-mens in 2016-2023,among which gram-negative bacteria accounted for 51.74％.The species of bacteria that ranked the top 5 places were as follows:Escherichia coli,Klebsiella pneumoniae,Staphylococcus epidermidis,Staphylococcus hominis,and Staphylococcus aureus.The isolation rates of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus were 28.32％and 74.94％,respectively;the strains maintained high sensitivity to linezolid and vancomycin,with the drug resistance rates no more than 2.50％.The drug resistance rates of Enterococcus faecium and Enterococcus faecalis to linezolid and vancomycin were always less than 4.20％.Among the species of Enterobacter,the drug resistance rates of the E.coli strains to meropenem declined from 17.65％to 5.94％;conversely,the drug resistance rate of the K.pneumoniae strains to carbapenems reached high up to 54.36％,showing an upward trend on the whole.Among the non-fermenting gram-negative bacteria,the drug resistance rate of the A.baumannii strains to carbapenems remained high(about 80.00％);while the drug resistance rates of the P.aeruginosa strains to meropenem dropped from 60.71％down to 24.32％.CONCLUSIONS The gram-negative bacteria are dominant among the pathogens isolated from the ster-ile body fluids in the hospital between 2016 and 2023.Although some major species of drug-resistant pathogens are effectively under control,the pathogens isolated from the sterile body fluid specimens maintain varying degree of drug resistance to various types of antibiotics.

To construct a recombinant fowl adenovirus 4(FAdV-4)expressing the Cap protein of goose astrovirus genotype 2(GoAstV-2),the expression cassette of Cap gene was inserted into the natural 1 966 bp deletion region of the FAdV-4 genome in the infectious clone p15A-cm-FAdV4-HNJZ.The resulted recombinant plasmid p15A-cm-FAdV4-HNJZ-Cap/GoAstV-2 was linearized with restriction enzyme and transfected into chicken hepatoma cell line(LMH)to rescue the recombinant FAdV-4 expressing the Cap protein of GoAstV-2,rF Ad V4-Cap/GoAstV-2.After 15 passages in LMH cells,the recombinant rFAdV4-Cap/GoAstV-2 was identified by PCR using primers flanking the insertion site of the Cap gene expression cassette and using viral genome DNA extracted from rFAdV4-Cap/GoAstV-2 infected LMH cells as template.LMH cells were in-fected with 15th passage rFAdV4-Cap/GoAstV-2 and indirect immunofluorescence was performed with a polyclonal antibody against Cap protein as the primary antibody.Western blot was carried out with lysates of rFAdV4-Cap/GoAstV-2 infected LMH cells.The in vitro replication dynamic of the 15th passage of the rFAdV4-Cap/GoAstV-2 was also investigated in LMH cells.The results demonstrated that the Cap gene of GoAstV-2 was presented in the genome of the recombinant vi-rus rF AdV4-Cap/Go Ast V-2,and could be expressed stably.The prepared recombinant virus in this study will lay a foundation for developing inactivated bivalent vaccine candidate against co-in-fection of FAdV-4 and GoAstV-2 in goose.

Objective To explore and analyze the characteristics and transmission routes of carbapenem-resistant Klebsiella pneumoniae(CRKP)strains in intensive care unit(ICU).Methods From January to October 2023,17 clinical infection isolates(clinical infection group),5 active screening isolates(active screening group),and 7 envi-ronmental isolates(environmental group)of CRKP in the liver surgery ICU of a hospital were selected and analyzed by whole-genome sequencing.The differences in resistance genes,virulence genes,and sequence typing(ST)were compared,and transmission routes were analyzed based on the phylogenetic tree.Results 29 strains of CRKP car-ried 4-18 resistance genes and 52-98 virulence genes,respectively.There were no statistically significant diffe-rences in genotype distribution of resistance genes,the number of virulence genes,and gene types among three groups of CRKP(all P＞0.05).ST showed that 29 CRKP strains mainly consisted of two categories:ST11 and ST15.Based on the phylogenetic tree constructed from the core genome,there were 7 highly homologous groups of CRKP,among which 4 groups had clear epidemiological associations.Conclusion CRKP in ICU carries more re-sistance and virulence genes,and some strains are highly homologous in ST and phylogenetic tree,which may lead to cross transmission.In the future,prevention and control measures should be strengthened to reduce the trans-mission of CRKP.

Objective:To investigate the clinical distribution characteristics changes in antimicrobial resistance, and carbapenemase resistance genes of Klebsiella pneumoniae isolated from children in Chongqing region during the period of January 2019 to December 2024, providing a basis for the rational use of antibiotics and the prevention and control of nosocomial infections.Methods:An observational study was conducted to retrospectively analyze 5 020 Klebsiella pneumoniae (KP) isolates detected in four hospitals of the Southwest Pediatric Laboratory Specialty Alliance. Antimicrobial susceptibility testing was performed by the minimum inhibitory concentration method combined with the disk diffusion method. Results were interpreted according to the 2024 Clinical and Laboratory Standards Institute (CLSI) standards. Carbapenemase resistance genes were detected by polymerase chain reaction (PCR) combined with Sanger sequencing. WHONET 5.6 was used for resistance analysis and SPSS 19.0 for statistical analysis. The chi-square test was used to assess trends in resistance rates, ESBL detection rates, and resistance rates of different CRKP carbapenemase genotypes from 2019 to 2024. Statistical significance was confirmed if the two-tailed P-value was <0.05. Results:A total of 5 020 strains were isolated, with a detection rate of 5.1% (5 020/99 063). The majority were from sputum (59.2%, 2 970/5 020), followed by pus (17.1%, 857), urine (9.7%, 487), venous blood (6.5%, 326), secretions (2.6%, 130), and other specimens (5.0%, 250).The lowest resistance rate was to amikacin (3.8%), followed by levofloxacin (10.9%), imipenem (19.1%), and meropenem (19.9%). Resistance rates to cefoperazone/sulbactam ( χ2=9.982 0, P=0.001 6), piperacillin/tazobactam ( χ2=10.110 0, P=0.001 5), ceftazidime ( χ2=3.849 0, P=0.049 8), cefotaxime ( χ2=7.605 0, P=0.005 8), cefepime ( χ2=13.510 0, P=0.000 2), aztreonam ( χ2=6.457 0, P=0.011 1), imipenem ( χ2=4.672 0, P=0.030 7), and levofloxacin ( χ2=7.555 0, P=0.006 0) showed an annual increasing trend. The main carbapenemase genes were blaNDM-5 (42.2%, 127/301), blaNDM-1 (33.9%, 102/301), and blaKPC-2 (17.3%, 52/301). Patients with KPC-2-producing strains (median age, 240 days) were older than those with NDM-1/NDM-5-producing strains (median age, 40 days) ( χ2=22.620 0, P<0.000 1). In neonatal wards, the detection rate of NDM-KP was higher than that of KPC-KP (64.6%, 148/229 vs. 26.9%, 14/52, χ2=24.680 0, P<0.000 1), whereas in ICUs, it was lower (6.1%, 14/229 vs. 26.9%, 14/52, χ2=20.450 0, P<0.000 1). Conclusion:In Chongqing region, the isolation rate of K. pneumoniae from sputum was the highest with most cases from neonatal wards. Resistance to carbapenems showed an upward trend. BlaNDM-5 was the predominant genotype in pediatric CRKP. Patients with KPC-KP were older than those with NDM-KP. NDM-KP predominated in neonatal wards, while KPC-KP predominated in ICUs, with KPC-KP showing higher antimicrobial resistance.

OBJECTIVE To investigate the distribution and drug resistance of the pathogens isolated from sterile body fluids in a hospital so as to provide reference for clinical treatment of the infections.METHODS The sterile body fluids specimens that were cultured positive for pathogens were retrospectively collected from a three-A hos-pital of Jiangxi Province between 2016 and 2023.The distribution and drug resistance of the isolated pathogens were observed.RESULTS Totally 16,658 strains of pathogens were isolated from the sterile body fluid speci-mens in 2016-2023,among which gram-negative bacteria accounted for 51.74％.The species of bacteria that ranked the top 5 places were as follows:Escherichia coli,Klebsiella pneumoniae,Staphylococcus epidermidis,Staphylococcus hominis,and Staphylococcus aureus.The isolation rates of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus were 28.32％and 74.94％,respectively;the strains maintained high sensitivity to linezolid and vancomycin,with the drug resistance rates no more than 2.50％.The drug resistance rates of Enterococcus faecium and Enterococcus faecalis to linezolid and vancomycin were always less than 4.20％.Among the species of Enterobacter,the drug resistance rates of the E.coli strains to meropenem declined from 17.65％to 5.94％;conversely,the drug resistance rate of the K.pneumoniae strains to carbapenems reached high up to 54.36％,showing an upward trend on the whole.Among the non-fermenting gram-negative bacteria,the drug resistance rate of the A.baumannii strains to carbapenems remained high(about 80.00％);while the drug resistance rates of the P.aeruginosa strains to meropenem dropped from 60.71％down to 24.32％.CONCLUSIONS The gram-negative bacteria are dominant among the pathogens isolated from the ster-ile body fluids in the hospital between 2016 and 2023.Although some major species of drug-resistant pathogens are effectively under control,the pathogens isolated from the sterile body fluid specimens maintain varying degree of drug resistance to various types of antibiotics.

To construct a recombinant fowl adenovirus 4(FAdV-4)expressing the Cap protein of goose astrovirus genotype 2(GoAstV-2),the expression cassette of Cap gene was inserted into the natural 1 966 bp deletion region of the FAdV-4 genome in the infectious clone p15A-cm-FAdV4-HNJZ.The resulted recombinant plasmid p15A-cm-FAdV4-HNJZ-Cap/GoAstV-2 was linearized with restriction enzyme and transfected into chicken hepatoma cell line(LMH)to rescue the recombinant FAdV-4 expressing the Cap protein of GoAstV-2,rF Ad V4-Cap/GoAstV-2.After 15 passages in LMH cells,the recombinant rFAdV4-Cap/GoAstV-2 was identified by PCR using primers flanking the insertion site of the Cap gene expression cassette and using viral genome DNA extracted from rFAdV4-Cap/GoAstV-2 infected LMH cells as template.LMH cells were in-fected with 15th passage rFAdV4-Cap/GoAstV-2 and indirect immunofluorescence was performed with a polyclonal antibody against Cap protein as the primary antibody.Western blot was carried out with lysates of rFAdV4-Cap/GoAstV-2 infected LMH cells.The in vitro replication dynamic of the 15th passage of the rFAdV4-Cap/GoAstV-2 was also investigated in LMH cells.The results demonstrated that the Cap gene of GoAstV-2 was presented in the genome of the recombinant vi-rus rF AdV4-Cap/Go Ast V-2,and could be expressed stably.The prepared recombinant virus in this study will lay a foundation for developing inactivated bivalent vaccine candidate against co-in-fection of FAdV-4 and GoAstV-2 in goose.

Objective To explore and analyze the characteristics and transmission routes of carbapenem-resistant Klebsiella pneumoniae(CRKP)strains in intensive care unit(ICU).Methods From January to October 2023,17 clinical infection isolates(clinical infection group),5 active screening isolates(active screening group),and 7 envi-ronmental isolates(environmental group)of CRKP in the liver surgery ICU of a hospital were selected and analyzed by whole-genome sequencing.The differences in resistance genes,virulence genes,and sequence typing(ST)were compared,and transmission routes were analyzed based on the phylogenetic tree.Results 29 strains of CRKP car-ried 4-18 resistance genes and 52-98 virulence genes,respectively.There were no statistically significant diffe-rences in genotype distribution of resistance genes,the number of virulence genes,and gene types among three groups of CRKP(all P＞0.05).ST showed that 29 CRKP strains mainly consisted of two categories:ST11 and ST15.Based on the phylogenetic tree constructed from the core genome,there were 7 highly homologous groups of CRKP,among which 4 groups had clear epidemiological associations.Conclusion CRKP in ICU carries more re-sistance and virulence genes,and some strains are highly homologous in ST and phylogenetic tree,which may lead to cross transmission.In the future,prevention and control measures should be strengthened to reduce the trans-mission of CRKP.

Objective To investigate the clinical value of prophylactic high-flow nasal cannula oxygen therapy (HFNC) in reducing postoperative pulmonary complication (PPC) in elderly patients with non-small cell lung cancer (NSCLC). Methods The clinical data of elderly patients (over 60 years) with NSCLC who underwent video-assisted thoracoscopic lobectomy or segmental resection at the Department of Thoracic Surgery, Fujian Provincial Hospital from January 2021 to March 2022 were retrospectively analyzed. According to whether receiving HFNC after surgery, they were divided into a conventional oxygen therapy (CO) group and a HFNC group. The CO group were matched with the HFNC group by the propensity score matching method at a ratio of 1 : 1. We compared PPC incidence, white blood cell (WBC) count, procalcitonin and C-reactive protein on postoperative day (POD) 1, 3 and 5 and postoperative hospital stay between the two groups. Results A total of 343 patients (165 males, 178 females, average age of 67.25±4.79 years) were enrolled, with 53 (15.45%) receiving HFNC. Before matching, there were statistical differences in gender, rate of combined chronic obstructive pulmonary disease, pathology type and TNM stage between the two groups (all P<0.05). There were 42 patients successfully matched in each of the two groups, with no statistical difference in baseline characteristics (P>0.05). After propensity score matching, the results showed that the PPC incidence in the HFNC group was lower than that in the CO group (23.81% vs. 45.23%, P=0.039). WBC count on POD 3 and 5 and procalcitonin level on POD 3 were less or lower in the HFNC group than those in the CO group [ (8.92±2.91)×109/L vs. (10.62±2.67)×109/L; (7.68±1.58)×109/L vs. (8.86±1.76)×109/L; 0.26 (0.25, 0.44) μg/L vs. 0.31 (0.25, 0.86) μg/L; all P<0.05]. There was no statistical difference in the other inflammatory indexes or the postoperative hospital stay between the two groups (P>0.05). Conclusion Prophylactic HFNC can reduce the PPC incidence and postoperative inflammatory indexes in elderly patients with NSCLC, but does not shorten the postoperative hospital stay.

Objective:To investigate the effects of ultrasound-guided serratus anterior plane block (SAPB) on hemodynamics in children with microtia undergoing auricular reconstruction.Methods:This research was a prospective randomized control study. Patients were prospectively recruited from March 2022 to July 2022 at the Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Children with microtia undergoing auricular reconstruction with costal cartilage were randomly included in either a SAPB-pre group(SAPB pre-rib harvest group) or a SAPB-post group(SAPB post-rib harvest group). Both groups of children were anesthetized with combined intravenous and inhalation anesthesia. Anesthesia maintenance was provided with i. v. propofol 4-6 mg·kg -1·h -1 and remifentanil 0.1-0.3 μg·kg -1·min -1, sevoflurane at 1% concentration, and a flow rate of 2.5 L/min. During the operation, bispectral index(BIS) was maintained between 40-60, and alterations in mean arterial pressure (MAP) and heart rate (HR) were <20%, compared to the basic values. During the operation, 1% sevoflurane was inhaled to maintain anesthesia. The fluctuation of BIS, MAP, and HR was adjusted by the intraoperative infusion of remifentanil and propofol. Ultrasound-guided SAPB in the SAPB-pre group was performed by an anesthesiologist after tracheal intubation of general anesthesia. In the SAPB-post group, ultrasound-guided SAPB was performed by the same anesthesiologist before the tracheal catheter was removed at the end of the operation, and the concentration of ropivacaine was 0.25% (3 mg/kg). MAP, HR, and BIS were recorded at each time point of admission, pre-rib harvest, during-rib harvest, post-rib harvest, anesthesia extubation, leaving the room. The consumptions of propofol and remifentanil during the operation were also recorded. Continuous data were presented as Mean±SD. Non-repeated measurement parametric variables were compared using the independent samples t-test. Repeated measurement parametric variables were assessed using repeated measures analysis of variance. The same data at varying time points were compared using Dunnett- t test of multiple comparison procedures. Categorical data were compared using the Chi-square test. Results:Sixty children were randomized to SAPB-pre group and SAPB-post group and 30 in each group. The data of gender (boy 22/ girl 8 vs. boy 23/ girl 7), age[(8.03±1.07)years vs. (8.33±1.16)years], body mass index [(17.46±2.79)kg/m 2 vs. (17.23±2.11)kg/m 2], operation time[(185.33±16.29)min vs. (190.00±16.50)min] and length of costocartilage[(23.13±1.46)cm vs. (23.63±1.27)cm] between the two groups showed no significant differences ( P>0.05). There was no significant difference in MAP, HR and BIS values at the time of pre-rib harvest, during-rib harvest, and post-rib harvest in the SAPB-pre group ( P>0.05). In the SAPB-post group, the fluctuations of MAP, HR and BIS values at the time of pre-rib harvest, during-rib harvest and post-rib harvest were obvious ( P<0.01). The consumptions of propofol and remifentanil during the operation in the SAPB-pre group were significantly less than that in the SAPB-post group[(555.67±150.90)mg vs. (788.50±191.02)mg, P<0.01; (745.33±183.56)μg vs. (1 080.00±247.26)μg, P<0.01]. Conclusion:Ultrasound-guided serratus anterior plane block can stabilize the hemodynamics during auricular reconstruction using costal cartilage and reduce the consumption of general anesthetic.