Based on the interleukin-17(IL-17) signaling pathway, this study explores the effect and mechanism of Bufei Decoction on Klebsiella pneumoniae pneumonia in rats. SD rats were randomly divided into the control group, model group, Bufei Decoction low-dose group(6.68 g·kg~(-1)·d~(-1)), Bufei Decoction high-dose group(13.36 g·kg~(-1)·d~(-1)), and dexamethasone group(1.04 mg·kg~(-1)·d~(-1)), with 10 rats in each group. A pneumonia model was established by tracheal drip injection of K. pneumoniae. After successful model establishment, the improvement in lung tissue damage was observed following drug administration. Core targets and signaling pathways were screened using transcriptomics techniques. Real-time fluorescence quantitative polymerase chain reaction was used to detect the mRNA expression of core targets interleukin-6(IL-6), interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), and chemokine CXC ligand 6(CXCL6). Western blot was used to assess key proteins in the IL-17 signaling pathway, including interleukin-17A(IL-17A), nuclear transcription factor-κB activator 1(Act1), tumor necrosis factor receptor-associated factor 6(TRAF6), and downstream phosphorylated p38 mitogen-activated protein kinase(p-p38 MAPK), and phosphorylated nuclear factor-κB p65(p-NF-κB p65). Apoptosis of lung tissue cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL). The results showed that, compared with the control group, the model group exhibited significant pathological damage in lung tissue. The mRNA expression of IL-6, IL-1β, TNF-α, and CXCL6, as well as the protein levels of IL-17A, Act1, TRAF6, p-p38 MAPK/p38 MAPK, and p-NF-κB p65/NF-κB p65, were significantly increased, and the number of apoptotic cells was notably higher, indicating successful model establishment. Compared with the model group, both low-and high-dose groups of Bufei Decoction showed reduced pathological damage in lung tissue. The mRNA expression levels of IL-6, IL-1β, TNF-α, and CXCL6, and the protein levels of IL-17A, Act1, TRAF6, p-p38 MAPK/p38 MAPK, and p-NF-κB p65/NF-κB p65, were significantly decreased, with a significant reduction in apoptotic cells in the high-dose group. In conclusion, Bufei Decoction can effectively improve lung tissue damage and reduce inflammation in rats with K. pneumoniae. The mechanism may involve the regulation of the IL-17 signaling pathway and the reduction of apoptosis.
Animals ; Interleukin-17/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Signal Transduction/drug effects* ; Rats ; Male ; Klebsiella pneumoniae/physiology* ; Klebsiella Infections/immunology* ; Humans ; Lung/drug effects*

OBJECTIVE: To investigate the mechanism of autophagy in regulating bacterial translocation in intestinal infection caused by hypervirulent Klebsiella pneumonia (hvKp) and explore the method of reducing translocation infection of intestinal bacteria. METHODS: Fifty C57BL/6J mice were divided into gavage group (n = 40) and control group (CO group, n = 10). The gavage group was orally administered with 200 μL/d of hvKp (colony count of 10⁹ CFU/mL) continuously for 5 days to establish a hvKp intestinal infection model. CO group was given an equal amount of normal saline. After the experiment, the mice were anesthetized with lsofluraneand euthanized with cervical dislocation under anesthesia. Peripheral venous blood of mice was collected to detect bacterial translocation by 16S rDNA sequencing, then divided into translocation group (BT+ group) and non-translocation group (BT- group). Hematoxylin-eosin (HE) staining was used to evaluate intestinal morphology. The ultrastructural changes of intestinal tissues were observed by electron microscope. The levels of intestinal oxidative stress indicators such as superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GPx) were measured. Translocation was detected by in situ hybridization. The expression of tight junction protein microtubule-associated protein 1 light chain 3-II (LC3-II) and autophagy protein Beclin-1 were measured by Western blotting. The mRNA expression of tight junction proteins ZO-1 and Claudin-2 were detected by reverse transcription-polymerase chain reaction (RT-PCR). The expression of autophagy protein and tight junction protein were observed by immunofluorescence. RESULTS: Two out of 40 mice in the gavage group died after developing aspiration pneumonia. All mice in the CO group survived. The 16S rDNA sequencing results showed that no bacteria were detected in the peripheral blood of the CO group, but bacteria were detected in the peripheral blood of 18 mice in the gavage group, with a bacterial translocation rate of 47.4%. The BT- and BT+ groups showed intestinal mucosal tissue damage, with severe damage in the BT+ group. Compared with the CO group, the level of MDA in the BT- and BT+ groups were significantly increased, while the activities of SOD and GPx were significantly decreased. Compared with the BT- group, the MDA level in the BT+ group further increased, while the SOD and GPx activities further decreased [MDA (mmol/mg): 2.98±0.11 vs. 2.48±0.11, SOD (U/mg): 62.40±5.45 vs. 73.40±4.08, GPx (U/mg): 254.72±10.80 vs. 303.55±8.57, all P < 0.01]. The results of in situ hybridization detection showed that after continuous gastric lavage for 5 days, displaced hvKp was detected in the intestinal mucosal lamina propria and liver tissue of the BT+ group. Compared with the CO group, the protein expressions of LC3-II and Beclin-1 in the BT- and BT+ groups were significantly increased. The protein expressions of LC3-II and Beclin-1 in the BT+ group were obviously lower than those in the BT- group (LC3-II/β-actin: 0.38±0.04 vs. 0.70±0.09, Beclin-1/β-actin: 0.62±0.05 vs. 0.86±0.05, both P < 0.01), and there were autophagosomes in the intestinal mucosa. These results indicated that intestinal mucosal autophagy was activated after hvKp continuous gavage. Compared with CO group, the mRNA expressions of ZO-1 and Claudin-2 in the BT- and BT+ groups were significantly decreased. Compared with the BT- group, the mRNA expressions of ZO-1 and Claudin-2 in the BT+ group was further reduced [ZO-1 mRNA (2^-ΔΔCT): 0.78±0.06 vs. 0.88±0.06, Claudin-2 mRNA (2^-ΔΔCT): 0.40±0.04 vs. 0.70±0.06, both P < 0.01]. The immunofluorescence results showed that the fluorescence intensity of LC3-II, Beclin-1, ZO-1, and Claudin-2 in the BT+ group was significantly lower than that in the BT- group. CONCLUSION HvKp can activate intestinal mucosal autophagy and reduce the damage to intestinal mucosal barrier function by down-regulating oxidative stress level, reduce the occurrence of bacterial translocation.
Animals ; Oxidative Stress ; Mice, Inbred C57BL ; Autophagy ; Intestinal Mucosa/microbiology* ; Bacterial Translocation ; Mice ; Klebsiella Infections/microbiology* ; Superoxide Dismutase/metabolism* ; Beclin-1

OBJECTIVE: To develop and validate a predictive model for the risk of bloodstream infection (BSI) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP). METHODS: A literature search was conducted in PubMed, Cochrane Library, and Embase databases from inception to July 2022 to identify studies reporting statistically significant risk factors for CRKP-BSI. Relative risks (RR) were extracted and pooled. Based on factor weights, a risk-scoring model was established. For external validation, hospitalized CRKP-infected patients from January 2016 to January 2022 at Shanghai First People's Hospital were included. Clinical data were used to calculate individual risk scores. The predictive accuracy was assessed using receiver operator characteristic curve (ROC curve). Patients were stratified into low-to-intermediate-risk and high-risk groups based on the optimal cut-off, and CRKP BSI incidence was compared between groups. RESULTS: The literatures related to the risk factors of CRKP-BSI published from database inception to July 2022 was retrieved and screened from PubMed, Cochrane Library, and Embase. Fourteen risk factors were included in the scoring model: cardiovascular disease, severe neutropenia or immunosuppression, intensive care unit (ICU) stay history, prior hospitalization, carbapenem exposure, aminoglycoside exposure, antifungal exposure, endotracheal intubation or tracheostomy, mechanical ventilation, hemodialysis, central venous catheter, indwelling urinary catheter, CRKP colonization, and Klebsiella pneumoniae positivity at non infection sites. The total score ranged from 0 to 173.5 points. In the validation cohort of 230 CRKP-infected patients, 41 developed CRKP BSI. The model yielded an area under the curve (AUC) of 0.783 (95%CI was 0.689-0.876). The optimal cut off was 81.25 points, with sensitivity of 75.6% and specificity of 81.0%. Based on this cut off, 163 patients were categorized as low-to-intermediate risk and 67 patients as high risk. The incidence of CRKP BSI in the high-risk group was significantly higher than in the low-to-intermediate-risk group [64.2% (43/67) vs. 4.9% (8/163); RR = 13.175 (95%CI was 5.920-29.319), P < 0.001]. CONCLUSIONS The model, based on 14 routinely available clinical parameters, demonstrated good performance in predicting CRKP BSI risk and may assist clinicians in early identification of high risk patients.
Humans ; Klebsiella pneumoniae/drug effects* ; Klebsiella Infections/microbiology* ; Carbapenems/pharmacology* ; Risk Factors ; Bacteremia/microbiology* ; ROC Curve ; Carbapenem-Resistant Enterobacteriaceae

Humans ; Escherichia coli ; Klebsiella pneumoniae ; Retrospective Studies ; Hospitals, General ; Singapore/epidemiology* ; Escherichia coli Infections/epidemiology* ; Sepsis/drug therapy* ; beta-Lactamases ; Anti-Bacterial Agents/therapeutic use* ; Bacteremia/drug therapy* ; Microbial Sensitivity Tests

Objective: To understand the distribution and antimicrobial resistance of common bacteria from children aged 0-14 years from China Antimicrobial Resistance Surveillance System. Methods: Bacterial resistance data of 2 575 040 strains from children aged 0-14 years were extracted from the national bacterial resistance surveillance reports from October 2018 to September 2022 and resistance changes were further analyzed by comparing with all data in each year. Results: The total number of bacteria isolated from children in 2018-2022 ranged from 415 306-588 016 strains, accounted for 15.9% (514 193/3 234 372), 16.2% (572 107/3 528 471), 12.8% (415 306/3 249 123), 13.0% (485 418/3 743 027), and 12.2% (588 016/4 828 509), respectively. The proportions of gram-positive bacteria among children were 45.4% (233 456/514 193), 44.5% (254 869/572 107), 44.7% (185 756/415 306), 42.6% (206 903/485 418), and 41.7% (245 044/588 016), respectively. The top five isolates of gram-positive bacteria were Staphylococcus aureus (36.0%-38.8%), Streptococcus pneumoniae (27.1%-31.7%), Staphylococcus epidermidis (7.3%-9.3%), Enterococcus faecium (4.0%-4.8%), and Enterococcus faecium (2.5%-3.6%), and the top five isolates of gram-negative bacteria were Escherichia coli (21.8%-26.2%), Haemophilus influenzae (14.4%-26.4%), Klebsiella pneumoniae (10.1%-14.7%), Moraxella catarrhalis (7.3%-11.9%), and Pseudomonas aeruginosa (5.5%-6.8%). The bacteria from children aged 0-14 years commonly isolated from sputum samples (48.8%-57.0%). The prevalence of methicillin-resistant S. aureus was 28.7%-30.1%. The detection rates of vancomycin-resistant E. faecalis or E. faecium were 0.1%-0.3%. The proportions of non-cerebrospinal fluid-derived penicillin-resistant S. pneumoniae were 0.7%-1.6%. The prevalence of cefotaxime and (or) ceftriaxone-resistant E. coli and K. pneumoniae decreased were 43.7%-50.0% and 31.8%-42.7%, respectively. The resistant rates of E. coli to imipenem and meropenem were 1.2%-1.9% and 1.2%-2.0%, respectively, and the resistant rates of K. pneumoniae to imipenem and meropenem were 7.3%-10.1% and 8.2%-12.2%, respectively. About 6.6%-10.2% and 5.3%-9.6% of the P. aeruginosa isolates showed resistant to imipenem and meropenem, respectively, while 17.2%-24.0% and 19.0%-29.4% of the Acinetobacter baumannii isolates were resistant to imipenem and meropenem, respectively. Conclusions: There is no significant change in the composition of common clinical pathogens in children aged 0-14 years from 2018 to 2022. The prevalence of some resistant bacteria such as methicillin-resistant S. aureus and carbapenem-resistant Enterobacterales is decreasing. However, it is necessary to pay attention to antimicrobial resistance of bacteria from children and long-term monitoring of the prevalence of resistant bacteria should be conducted.
Child ; Humans ; Anti-Bacterial Agents/therapeutic use* ; Meropenem ; Methicillin-Resistant Staphylococcus aureus ; Escherichia coli ; Microbial Sensitivity Tests ; Bacteria ; Gram-Positive Bacteria ; Staphylococcal Infections/drug therapy* ; Klebsiella pneumoniae ; Imipenem ; Drug Resistance, Bacterial

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to β-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.
Humans ; Klebsiella pneumoniae/genetics* ; Multilocus Sequence Typing ; Retrospective Studies ; Klebsiella Infections/drug therapy* ; Anti-Bacterial Agents/therapeutic use* ; Hospitals ; Carbapenem-Resistant Enterobacteriaceae/genetics* ; Microbial Sensitivity Tests ; Carbapenems/pharmacology*

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to β-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.
Humans ; Klebsiella pneumoniae/genetics* ; Multilocus Sequence Typing ; Retrospective Studies ; Klebsiella Infections/drug therapy* ; Anti-Bacterial Agents/therapeutic use* ; Hospitals ; Carbapenem-Resistant Enterobacteriaceae/genetics* ; Microbial Sensitivity Tests ; Carbapenems/pharmacology*

Abscess/diagnosis* ; Cardiac Tamponade/etiology* ; Humans ; Klebsiella Infections/diagnosis* ; Klebsiella pneumoniae ; Mediastinal Diseases/diagnostic imaging*

Anti-Bacterial Agents/therapeutic use* ; Bacteremia ; Carbapenems/therapeutic use* ; Cross Infection/drug therapy* ; Drug Resistance, Bacterial ; Humans ; Intensive Care Units ; Klebsiella Infections/drug therapy* ; Klebsiella pneumoniae ; Pneumonia/drug therapy* ; Risk Factors

BACKGROUND: Carbapenemase-producing Klebsiella pneumoniae (CP-Kp) poses distinct clinical challenges due to extensively drug resistant (XDR) phenotype, and sequence type (ST) 11 is the most dominant blaKPC-2-bearing CP-Kp clone in China. The purpose of this current retrospective study was to explore the genetic factors associated with the success of XDR CP-Kp ST11 strains circulated in the intensive care unit (ICU) of a Chinese tertiary hospital. METHODS: Six ST11 XDR CP-Kp strains were identified between May and December 2014 and validated by minimum inhibitory concentration examination, polymerase chain reaction, and pyrosequencing. The six ST11 XDR CP-Kp, as well as three multi-drug resistant (MDR) and four susceptible strains, were sequenced using single-molecule real-time method. Comprehensively structural and functional analysis based on comparative genomics was performed to identify genomic characteristics of the XDR ST11 CP-Kp strains. RESULTS: We found that ST11 XDR blaKPC-2-bearing CP-Kp strains isolated from inpatients spread in the ICU of the hospital. Functionally, genes associated with information storage and processing of the ST11 XDR CP-Kp strains were more abundant than those of MDR and susceptible strains, especially genes correlative with mobile genetic elements (MGEs) such as transposons and prophages. Structurally, eleven large-scale genetic regions taken for the unique genome in these ST11 XDR CP-Kp strains were identified as MGEs including transposons, integrons, prophages, genomic islands, and integrative and conjugative elements. Three of them were located on plasmids and eight on chromosomes; five of them were with antimicrobial resistance genes and eight with adaptation associated genes. Notably, a new blaKPC-2-bearing ΔΔTn1721-blaKPC-2 transposon, probably transposed and truncated from ΔTn1721-blaKPC-2 by IS903D and ISKpn8, was identified in all six ST11 XDR CP-Kp strains. CONCLUSION Our findings suggested that together with clonal spread, MGEs identified uniquely in the ST11 XDR CP-Kp strains might contribute to their formidable adaptability, which facilitated their widespread dissemination in hospital.
Anti-Bacterial Agents ; Bacterial Proteins ; China ; Electrophoresis, Gel, Pulsed-Field ; Hospitals ; Humans ; Klebsiella Infections/drug therapy* ; Klebsiella pneumoniae/genetics* ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Pharmaceutical Preparations ; Retrospective Studies ; beta-Lactamases/genetics*