Objective:To analyze the short-term hospital-based transmission characteristics and gene variation of Carbapenem-Resistant Klebsiella pneumoniae (CRKP) by genome-wide technique to provide evidence for transmission control. Methods:The experimental strain was derived from all the CRKP isolated in Affiliated Hospital of North China University of Science and Technology from October 2022 to December 2023. Strain identification and drug susceptibility were tested with VITEK 2-Compact automatic bacterial identification drug susceptibility analyzer or disk method, and the results were interpreted through whole genome sequencing. The ST type, carbapenem resistance gene, virulence factor, and O serotype of the collected strains were analyzed.Results:Among the 115 strains of CRKP, 94 strains were isolated from the intensive care unit (ICU), accounting for 81.7%, and 21 strains were isolated from the non-intensive care unit (NICU), accounting for 18.3%. The 115 strains of CRKP can be divided into 11 ST types, of which ST11 type was the most (54.8%, 63/115), followed by ST15 type (22.6%, 26/115) and ST5492 type (15.7%, 18/115). Type ST5492 was a new clonal group in the region. The 115 strains of CRKP could be divided into 7 O serotypes, most of which were O2a type(32.2%,37/115), followed by O5 type(30.4%,35/115) and O1 type(27.8%,32/115). The resistance genes of carbapenem antibiotics showed that there were 107 strains carrying the blaKPC-2 gene, one strain with the blaNDM-1 gene, and one strain with both the blaKPC-2 and blaNDM-13 genes. Virulence genes were detected in 55 CRKP strains (47.8%, 55/115), among which six strains detected peg-344, iucA, iroB, rmpA, and rmpA2 virulence genes (5.2%, 6/115). Four virulence genes ( peg-344, iucA, rmpA, and rmpA2) were detected in 34 strains (29.6%, 34/115). Three virulence genes ( iucA, iroB and rmpA) were detected in two strains (1.7%, 2/115). Three virulence genes ( peg-344, iucA and rmpA) were detected in one strain (0.8%, 1/115). IucA and rmpA virulence genes were detected in 12 strains (10.4%, 12/115). KPC-2_ST11_O2a, KPC-2_ST15_O1 and KPC-2_ST5492_O5 were dominant clones, and their distribution was mainly in the intensive care unit. The whole genome sequence analysis showed that there were three dominant clones, among which ST11 clones were subdivided into three dominant O serotypes, all of which were mainly in the intensive care unit. Conclusion:The popular strain in the hospital of CRKP is a KPC-2_ST11 clone group carrying iucA, rmpA/rmpA2, with cross-department transmission and mutation. ST5492 is a newly-launched clone type. The intensive care unit of hvKP carrying five virulence genes, including peg-344, should be alert to the epidemic risk of CR-hvKP outbreak.

Objective:To investigate the epidemiological dynamics and spatiotemporal diffusion trend of brucellosis in China from 2010 to 2024.Methods:Data on reported human brucellosis cases in mainland China from January 1, 2010, to December 31, 2024, were collected via the"China Information System for Disease Control and Prevention", including detailed information on the date of onset, gender, age, occupation, and residential address of the cases. The Joinpoint regression and spatial interpolation techniques were used to investigate the spatiotemporal dynamics and population distribution characteristics of human brucellosis in pastoral/semi-pastoral areas and other regions, as well as urban and rural areas, and explore the epidemic trends of the disease.Results:From 2010 to 2024, pastoral/semi-pastoral regions reported 252 094 brucellosis cases, with a mean annual incidence rate of 36.57±7.28 per 100 000. In contrast, other regions cumulatively recorded 519 748 cases during the same period, demonstrating a significantly lower mean annual incidence rate of 2.54±0.74 per 100 000. The incidence rate of human brucellosis in pastoral/semi-pastoral regions exhibited a declining-rebounding-declining trend. Specifically, the incidence rate decreased significantly from 2010 to 2017 (APC=-7.20; P<0.001) and increased notably from 2017 to 2021 (APC=18.00; P=0.015) with a decline again from 2021 to 2024 (APC=-7.53; P=0.027). In other regions, the incidence rate showed a fluctuating upward trend. Specifically, the incidence rate increased significantly from 2010 to 2015 (APC=20.37; P<0.001) and decreased notably from 2015 to 2018 (APC=-21.78; P<0.001), followed by an increase again from 2018 to 2024, a significant upward trend in incidence rate from 2018 to 2021 (APC=26.73; P<0.001) and a non-significant decline from 2021 to 2024 (APC=-0.99; P=0.735), resulting in the maintenance of a relatively high incidence level. Rural areas demonstrated significantly higher brucellosis incidence rates than urban settings (all P<0.001). Brucellosis exhibited a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions between 2010 and 2024. The age structure of patients in pastoral/semi-pastoral areas differed significantly from that in other regions. Specifically, in pastoral/semi-pastoral areas, the incidence rate was higher among the 35-49 age groups, while in other regions, the incidence rate was higher among those aged 55-64. Conclusion:There are notable disparities in the incidence of human brucellosis between pastoral/semi-pastoral areas and other regions in China. Human brucellosis exhibits a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions.

Objective:To analyze the carriage status, subtype distribution and flanking gene sequence characteristics of oxacillinases (OXA enzyme) in 241 clinical strains of Pseudomonas aeruginosa, and assess their roles in the drug resistance of Pseudomonas aeruginosa and ability to horizontally transfer across species. Methods:Clinical P. aeruginosa isolates were collected from four hospitals in Sanya, Tangshan, Zhangjiakou, and Beijing. The prevalence of oxacillinases and their flanking gene sequences was analyzed by whole-genome sequencing (NGS) and bioinformatic approaches. Results:A total of 241 isolates of P. aeruginosa were gathered, and 35 blaOXA subtypes were identified through screening of 252 blaOXA genes. These genes were classified into three subfamilies: blaOXA-50-like (241, 95.6%), blaOXA-1-like (9, 3.6%) and blaOXA-10-like (2, 0.8%). Among these, 11 subtypes (11, 31.4%) were novel blaOXA subtypes. Nine of these belonged to the blaOXA-50-like subfamily and were designated as blaOXA-1244, blaOXA-1245, blaOXA-1246, blaOXA-1250, blaOXA-1252, blaOXA-1253, blaOXA-1254, blaOXA-1255, and blaOXA-1256. The remaining two belonged to the blaOXA-10-like subfamily and were named blaOXA-1247 and blaOXA-1248. Compared to the amino acid sequence of OXA-10, the newly identified subtype OXA-1247 exhibited a mutation at position 117, where a valine was replaced by a leucine. This change was thought to improve the enzyme′s ability to hydrolyze carbapenems. In the analysis of the flanking sequences of the blaOXA genes, Class I integrons were identified in four bacterial strains. The variable regions of these integrons carried three distinct patterns of resistance gene cassettes: aac( 6′) -Ib-blaOXA-1247-ant( 3′′) -Ia, aac( 6′) -Ib-blaOXA-1248 and aac( 6′) -Ib- blaIMP-45-blaOXA-1-catB3. Among these, the strain BJ2326 carried a class I integron that was connected to the downstream IS CR1 element to form a composite class I integron structure, additionally carrying the resistance gene blaPER-1. Out of the 223 non-wild-type P. aeruginosa strains, 127 strains exhibited non-wild-type profiles to the four beta-lactam antibiotics MEM, CAZ, FEP, and TZP, with the combination of MEM+CAZ+FEP being the most prevalent, representing 57.0% of the total. Conclusions:The blaOXA genes in 241 clinical P. aeruginosa strains showed diversity. Some blaOXA genes had a co-transfer risk with the metallo-β-lactamase resistance gene blaIMP-45. Among the 11 newly discovered blaOXA subtypes, the new subtype OXA-1247 may have carbapenemase activity and potential for horizontal transfer.

BACKGROUND:We have successfully isolated and cultured neonatal mouse cerebrospinal fluid-contacting neurons in vitro,but there is no study that reports an effective method for isolating and culturing high-purity adult mouse cerebrospinal fluid-contacting neurons.There is no study on whether the self-renewal ability of cerebrospinal fluid-contacting neurons changes with age.OBJECTIVE:To establish a method for isolating and culturing high-purity adult mouse cerebrospinal fluid-contacting neurons in vitro,and to characterize the self-renewal ability of adult mouse cerebrospinal fluid-contacting neurons and neonatal mouse cerebrospinal fluid-contacting neurons in vitro.METHODS:Primary cells containing cerebrospinal fluid-contacting neurons were isolated from the cervical medulla of adult mouse (3 months of age) in adherent culture and transfected with lentivirus fused with multimodal imaging genes.High-purity adult mouse cerebrospinal fluid-contacting neurons were obtained by puromycin screening in suspension culture in complete medium.The expression of neural stem cell markers Nestin and SOX2 was detected by immunofluorescence in adult mouse cerebrospinal fluid-contacting neurons,and the ability of adult mouse cerebrospinal fluid-contacting neurons to form spheres and pass on in vitro was observed.An equal number (5×103/mL) of passage 3 adult mouse and neonatal mouse cerebrospinal fluid-contacting neurons were divided into two groups under the same conditions and inoculated into ultra-low adhesion plates containing complete medium in suspension culture at 5％ CO2,37℃ thermostat,respectively.The self-renewal capacity of adult mouse and neonatal mouse cerebrospinal fluid-contacting neurons was characterized by in vitro spheroid formation,CCK8 assay,qPCR,and western blot assay.RESULTS AND CONCLUSION:(1) High-purity cerebrospinal fluid-contacting neurons were successfully isolated from adult mouse,which expressed Nestin and SOX2 in vitro,and were able to form neurospheres and pass on continuously.(2) The in vitro self-renewal ability of cerebrospinal fluid-contacting neurons in adult mouse was significantly weaker than that of neonatal mouse,and the neurospheres formed by day 4 of cell culture in neonatal mouse were about 150 μm in diameter,whereas the neurospheres formed by adult mouse tactile neurons were only 40 μm in diameter (P<0.0001).(3) CCK8 proliferation assay showed that the proliferative activity of adult mouse cerebrospinal fluid-contacting neurons was significantly weaker than that of neonatal mouse at all time points after culture (P<0.0001).(4) qPCR and western blot assay revealed that the mRNA (P<0.0001) and protein expression levels (P<0.01) of Nestin and SOX2 in cerebrospinal fluid-contacting neurons of adult mouse were significantly decreased compared with those of neonatal mouse.(5) The above results indicated that the self-renewal ability of cerebrospinal fluid-contacting neurons in adult mouse was significantly weaker than that of neonatal mouse in vitro.

Efferocytosis refers to the process of phagocytes engulfing and clearing the cells after programmed cell death. In recent years, an increasing number of studies have shown that the mechanisms of efferocytosis are closely related to drug-induced liver injury, hepatic ischemia-reperfusion injury, viral hepatitis, cholestatic liver diseases, metabolic-associated fatty liver disease, alcoholic liver disease, and other liver disorders. This review summarized the research progress on the role of efferocytosis in liver diseases, with the hope of providing new targets for the prevention and treatment of liver diseases.
Humans ; Liver Diseases/metabolism* ; Animals ; Phagocytosis/physiology* ; Phagocytes ; Efferocytosis

Objective:To analyze the short-term hospital-based transmission characteristics and gene variation of Carbapenem-Resistant Klebsiella pneumoniae (CRKP) by genome-wide technique to provide evidence for transmission control. Methods:The experimental strain was derived from all the CRKP isolated in Affiliated Hospital of North China University of Science and Technology from October 2022 to December 2023. Strain identification and drug susceptibility were tested with VITEK 2-Compact automatic bacterial identification drug susceptibility analyzer or disk method, and the results were interpreted through whole genome sequencing. The ST type, carbapenem resistance gene, virulence factor, and O serotype of the collected strains were analyzed.Results:Among the 115 strains of CRKP, 94 strains were isolated from the intensive care unit (ICU), accounting for 81.7%, and 21 strains were isolated from the non-intensive care unit (NICU), accounting for 18.3%. The 115 strains of CRKP can be divided into 11 ST types, of which ST11 type was the most (54.8%, 63/115), followed by ST15 type (22.6%, 26/115) and ST5492 type (15.7%, 18/115). Type ST5492 was a new clonal group in the region. The 115 strains of CRKP could be divided into 7 O serotypes, most of which were O2a type(32.2%,37/115), followed by O5 type(30.4%,35/115) and O1 type(27.8%,32/115). The resistance genes of carbapenem antibiotics showed that there were 107 strains carrying the blaKPC-2 gene, one strain with the blaNDM-1 gene, and one strain with both the blaKPC-2 and blaNDM-13 genes. Virulence genes were detected in 55 CRKP strains (47.8%, 55/115), among which six strains detected peg-344, iucA, iroB, rmpA, and rmpA2 virulence genes (5.2%, 6/115). Four virulence genes ( peg-344, iucA, rmpA, and rmpA2) were detected in 34 strains (29.6%, 34/115). Three virulence genes ( iucA, iroB and rmpA) were detected in two strains (1.7%, 2/115). Three virulence genes ( peg-344, iucA and rmpA) were detected in one strain (0.8%, 1/115). IucA and rmpA virulence genes were detected in 12 strains (10.4%, 12/115). KPC-2_ST11_O2a, KPC-2_ST15_O1 and KPC-2_ST5492_O5 were dominant clones, and their distribution was mainly in the intensive care unit. The whole genome sequence analysis showed that there were three dominant clones, among which ST11 clones were subdivided into three dominant O serotypes, all of which were mainly in the intensive care unit. Conclusion:The popular strain in the hospital of CRKP is a KPC-2_ST11 clone group carrying iucA, rmpA/rmpA2, with cross-department transmission and mutation. ST5492 is a newly-launched clone type. The intensive care unit of hvKP carrying five virulence genes, including peg-344, should be alert to the epidemic risk of CR-hvKP outbreak.

Objective:To investigate the epidemiological dynamics and spatiotemporal diffusion trend of brucellosis in China from 2010 to 2024.Methods:Data on reported human brucellosis cases in mainland China from January 1, 2010, to December 31, 2024, were collected via the"China Information System for Disease Control and Prevention", including detailed information on the date of onset, gender, age, occupation, and residential address of the cases. The Joinpoint regression and spatial interpolation techniques were used to investigate the spatiotemporal dynamics and population distribution characteristics of human brucellosis in pastoral/semi-pastoral areas and other regions, as well as urban and rural areas, and explore the epidemic trends of the disease.Results:From 2010 to 2024, pastoral/semi-pastoral regions reported 252 094 brucellosis cases, with a mean annual incidence rate of 36.57±7.28 per 100 000. In contrast, other regions cumulatively recorded 519 748 cases during the same period, demonstrating a significantly lower mean annual incidence rate of 2.54±0.74 per 100 000. The incidence rate of human brucellosis in pastoral/semi-pastoral regions exhibited a declining-rebounding-declining trend. Specifically, the incidence rate decreased significantly from 2010 to 2017 (APC=-7.20; P<0.001) and increased notably from 2017 to 2021 (APC=18.00; P=0.015) with a decline again from 2021 to 2024 (APC=-7.53; P=0.027). In other regions, the incidence rate showed a fluctuating upward trend. Specifically, the incidence rate increased significantly from 2010 to 2015 (APC=20.37; P<0.001) and decreased notably from 2015 to 2018 (APC=-21.78; P<0.001), followed by an increase again from 2018 to 2024, a significant upward trend in incidence rate from 2018 to 2021 (APC=26.73; P<0.001) and a non-significant decline from 2021 to 2024 (APC=-0.99; P=0.735), resulting in the maintenance of a relatively high incidence level. Rural areas demonstrated significantly higher brucellosis incidence rates than urban settings (all P<0.001). Brucellosis exhibited a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions between 2010 and 2024. The age structure of patients in pastoral/semi-pastoral areas differed significantly from that in other regions. Specifically, in pastoral/semi-pastoral areas, the incidence rate was higher among the 35-49 age groups, while in other regions, the incidence rate was higher among those aged 55-64. Conclusion:There are notable disparities in the incidence of human brucellosis between pastoral/semi-pastoral areas and other regions in China. Human brucellosis exhibits a diffusion trend from the northern epidemic areas of China to neighboring regions, along with sporadic diffusion in southern regions.

Objective:To analyze the carriage status, subtype distribution and flanking gene sequence characteristics of oxacillinases (OXA enzyme) in 241 clinical strains of Pseudomonas aeruginosa, and assess their roles in the drug resistance of Pseudomonas aeruginosa and ability to horizontally transfer across species. Methods:Clinical P. aeruginosa isolates were collected from four hospitals in Sanya, Tangshan, Zhangjiakou, and Beijing. The prevalence of oxacillinases and their flanking gene sequences was analyzed by whole-genome sequencing (NGS) and bioinformatic approaches. Results:A total of 241 isolates of P. aeruginosa were gathered, and 35 blaOXA subtypes were identified through screening of 252 blaOXA genes. These genes were classified into three subfamilies: blaOXA-50-like (241, 95.6%), blaOXA-1-like (9, 3.6%) and blaOXA-10-like (2, 0.8%). Among these, 11 subtypes (11, 31.4%) were novel blaOXA subtypes. Nine of these belonged to the blaOXA-50-like subfamily and were designated as blaOXA-1244, blaOXA-1245, blaOXA-1246, blaOXA-1250, blaOXA-1252, blaOXA-1253, blaOXA-1254, blaOXA-1255, and blaOXA-1256. The remaining two belonged to the blaOXA-10-like subfamily and were named blaOXA-1247 and blaOXA-1248. Compared to the amino acid sequence of OXA-10, the newly identified subtype OXA-1247 exhibited a mutation at position 117, where a valine was replaced by a leucine. This change was thought to improve the enzyme′s ability to hydrolyze carbapenems. In the analysis of the flanking sequences of the blaOXA genes, Class I integrons were identified in four bacterial strains. The variable regions of these integrons carried three distinct patterns of resistance gene cassettes: aac( 6′) -Ib-blaOXA-1247-ant( 3′′) -Ia, aac( 6′) -Ib-blaOXA-1248 and aac( 6′) -Ib- blaIMP-45-blaOXA-1-catB3. Among these, the strain BJ2326 carried a class I integron that was connected to the downstream IS CR1 element to form a composite class I integron structure, additionally carrying the resistance gene blaPER-1. Out of the 223 non-wild-type P. aeruginosa strains, 127 strains exhibited non-wild-type profiles to the four beta-lactam antibiotics MEM, CAZ, FEP, and TZP, with the combination of MEM+CAZ+FEP being the most prevalent, representing 57.0% of the total. Conclusions:The blaOXA genes in 241 clinical P. aeruginosa strains showed diversity. Some blaOXA genes had a co-transfer risk with the metallo-β-lactamase resistance gene blaIMP-45. Among the 11 newly discovered blaOXA subtypes, the new subtype OXA-1247 may have carbapenemase activity and potential for horizontal transfer.

BACKGROUND:We have successfully isolated and cultured neonatal mouse cerebrospinal fluid-contacting neurons in vitro,but there is no study that reports an effective method for isolating and culturing high-purity adult mouse cerebrospinal fluid-contacting neurons.There is no study on whether the self-renewal ability of cerebrospinal fluid-contacting neurons changes with age.OBJECTIVE:To establish a method for isolating and culturing high-purity adult mouse cerebrospinal fluid-contacting neurons in vitro,and to characterize the self-renewal ability of adult mouse cerebrospinal fluid-contacting neurons and neonatal mouse cerebrospinal fluid-contacting neurons in vitro.METHODS:Primary cells containing cerebrospinal fluid-contacting neurons were isolated from the cervical medulla of adult mouse (3 months of age) in adherent culture and transfected with lentivirus fused with multimodal imaging genes.High-purity adult mouse cerebrospinal fluid-contacting neurons were obtained by puromycin screening in suspension culture in complete medium.The expression of neural stem cell markers Nestin and SOX2 was detected by immunofluorescence in adult mouse cerebrospinal fluid-contacting neurons,and the ability of adult mouse cerebrospinal fluid-contacting neurons to form spheres and pass on in vitro was observed.An equal number (5×103/mL) of passage 3 adult mouse and neonatal mouse cerebrospinal fluid-contacting neurons were divided into two groups under the same conditions and inoculated into ultra-low adhesion plates containing complete medium in suspension culture at 5％ CO2,37℃ thermostat,respectively.The self-renewal capacity of adult mouse and neonatal mouse cerebrospinal fluid-contacting neurons was characterized by in vitro spheroid formation,CCK8 assay,qPCR,and western blot assay.RESULTS AND CONCLUSION:(1) High-purity cerebrospinal fluid-contacting neurons were successfully isolated from adult mouse,which expressed Nestin and SOX2 in vitro,and were able to form neurospheres and pass on continuously.(2) The in vitro self-renewal ability of cerebrospinal fluid-contacting neurons in adult mouse was significantly weaker than that of neonatal mouse,and the neurospheres formed by day 4 of cell culture in neonatal mouse were about 150 μm in diameter,whereas the neurospheres formed by adult mouse tactile neurons were only 40 μm in diameter (P<0.0001).(3) CCK8 proliferation assay showed that the proliferative activity of adult mouse cerebrospinal fluid-contacting neurons was significantly weaker than that of neonatal mouse at all time points after culture (P<0.0001).(4) qPCR and western blot assay revealed that the mRNA (P<0.0001) and protein expression levels (P<0.01) of Nestin and SOX2 in cerebrospinal fluid-contacting neurons of adult mouse were significantly decreased compared with those of neonatal mouse.(5) The above results indicated that the self-renewal ability of cerebrospinal fluid-contacting neurons in adult mouse was significantly weaker than that of neonatal mouse in vitro.

Objective:To analyze the drug resistance characteristics of Klebsiella pneumoniae in the nasopharynx of hospitalized patients in North China from 2022 to 2023. Methods:From November 2022 to July 2023, nasopharyngeal swabs were collected from 100 inpatients in Affiliated Hospital of North China University of Science and Technology, and Klebsiella pneumoniae was isolated and cultured. At the same time, the clinical data of the patients were collected, including gender, age, department, clinical diagnosis of disease type, etc. The minimum inhibitory concentration of strains was detected by an automatic bacterial drug sensitivity system. The drug resistance genes, ST types, capsule serotypes and population structure of the strains were analyzed by whole genome sequencing and data analysis. Results:Klebsiella pneumoniae was isolated from 55 nasopharyngeal swabs of 100 inpatients(55.00%). Among the 55 inpatients with Klebsiella pneumoniae in the nasopharynx, 70.91% (39/55) were male, with an age distribution concentrated between 61 and 80 years old (58.18%, 32/55), and 50.91% (28/55) were in intensive care units (ICU). The main underlying disease type was nervous system disease (49.09%, 27/55). The results of drug sensitivity showed that the non-susceptibility rates of 55 strains of Klebsiella pneumoniae to cephalosporins, quinolones, aztreonam and nitrofurantoin were all more than 80.00%. Twenty-eight carbapenem-resistant Klebsiella pneumoniae strains (50.91%), 47 extended-spectrum β-lactamase producing strains (85.45%), and 48 multi-drug-resistant strains (87.27%) were detected. A total of 11 antibiotic resistance genes were detected, including carbapenems (carrying rate 76.36%) and extended-spectrum β-lactamase (carrying rate 96.36%). The 55 strains could be divided into 17 ST types, and the most common type was ST11 (25.45%). The 55 strains were divided into 18 capsular serotypes, among which K102 was the most prevalent (23.64%). OXA-1_ST307_K102 (21.82%) and KPC-2_ST5492_K125 (18.18%) were the dominant clones, distributed in the Department of Neurosurgery and ICU. The result of whole genome sequence analysis showed that there were four clusters with high homology among the 55 strains. The strains from the ICU formed two independent clusters, and strains from the Neurology ICU and Neurosurgery department formed one cluster respectively. Conclusion:The carrying rate of Klebsiella pneumoniae in the nasopharynx of inpatients is high, and the drug resistance of the strains is serious. There are many types of drug-resistant genes.