1.Effect and mechanism of Bufei Decoction on improving Klebsiella pneumoniae pneumonia in rats by regulating IL-17 signaling pathway.
Li-Na HUANG ; Zheng-Ying QIU ; Xiang-Yi PAN ; Chen LIU ; Si-Fan LI ; Shao-Guang GE ; Xiong-Wei SHI ; Hao CAO ; Rui-Hua XIN ; Fang-di HU
China Journal of Chinese Materia Medica 2025;50(11):3097-3107
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*
2.Autophagy reduces bacterial translocation by regulating intestinal mucosal oxidative stress.
Xing LU ; Chengfen YIN ; Yaxiao SU ; Xinjing GAO ; Fengmei WANG ; Lei XU
Chinese Critical Care Medicine 2025;37(2):153-159
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
3.Development and validation of a prediction model for bloodstream infection caused by carbapenem-resistant Klebsiella pneumoniae.
Shanshan JIN ; Fangqing ZHOU ; Dongpo WEI ; Jingjing ZHENG ; Changxing CHEN ; Ruilan WANG
Chinese Critical Care Medicine 2025;37(9):822-828
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
4.Analysis of fast-growing culturable bacteria and pathogenic bacteria in the surface water of the northeast coast of Hainan Island in China.
Mei XING ; Qiu Ye FU ; Si Si LIN ; Xiong FU ; Xiao Xia WANG ; Li Cheng WANG ; Xiong ZHU ; Ting Lan OUYANG
Chinese Journal of Preventive Medicine 2023;57(8):1206-1216
Objective: To obtain the diversity and abundance of fast-growing bacteria in the surface water of the northeast coast of Hainan Island in China, different cultivation methods were employed. This study also aims to provide a reference for isolating bacterial samples from seawater sources and preventing marine-derived pathogens. Methods: Based on the principles of taxonomic design, surface seawater samples were collected from six locations along the northeast coast of Hainan Island in China in March, June, October, and December 2021. Then, bacterial enrichment was performed based on traditional cultivation methods for Salmonella, Vibrio, Burkholderia pseudomallei, Actinomycetes, and general marine bacteria. After that, bacterial species identification was conducted by 16S rDNA amplicon sequencing and metagenomic sequencing. Results: A total of 1 151 fast-growing cultivable bacteria belonging to 66 genera and 213 species were identified using five different culture protocols. In different cultivation protocols, Bacillus and Klebsiella demonstrated extensive discriminatory advantages and ranked among the top genera in terms of abundance. Protocol 1 had Escherichia, Klebsiella, and Citrobacter as dominant genera. Pathogenic bacteria detected by protocol 1 included Klebsiella pneumoniae and Escherichia coli, with 37 and 29 strains respectively, while Salmonella enterica was uniquely detected with seven isolates. Proteus, Enterococcus, and Providencia were the dominant genera in protocol 2, and Proteus mirabilis was the most abundant pathogenic bacteria detected with 66 isolates. Vibrio cholerae was uniquely detected with six isolates at a higher abundance. Klebsiella, Escherichia, and Acinetobacter were the dominant genera in protocol 3, and Klebsiella pneumoniae was the most abundant pathogenic bacteria detected with 53 isolates, while Acinetobacter nosocomialis was uniquely detected with seven isolates. Vibrio and Pseudoalteromonas were the dominant genera in protocol 4, and they showed advantages in isolating and cultivating Marine-derived Vibrio. Exiguobacterium, Staphylococcus, and Bacillus were the dominant genera in protocol 5. Bacillus cereus and Lactococcus lactis were the most abundant pathogenic bacteria detected with 20 and 15 isolates, respectively, while Lactococcus lactis was uniquely detected at higher abundance. Metagenomic sequencing showed that Klebsiella pneumoniae was significantly dominant with a gene abundance of 51.11%, followed by Alcanivorax sp. at 12.57%. Conclusion: The surface water of the northeast coast of Hainan Island in China exhibits a rich diversity of bacteria, with Klebsiella pneumoniae being highly abundant in the studied area. Different cultivation methods demonstrate distinct selective advantages in culturing bacterial genera and pathogens. Therefore, it is necessary to optimize cultivation conditions for specific marine bacteria.
Humans
;
Water
;
Bacteria/genetics*
;
Seawater/microbiology*
;
Escherichia coli
;
Enterococcus
;
Klebsiella pneumoniae
;
China
5.Molecular epidemiological characterization of hypervirulent carbapenem-resistant Klebsiella pneumoniae in a hospital in Henan Province from 2020 to 2022.
Xin Wei LIU ; Deng Zhou LI ; Yue HU ; Rui ZHU ; Dong Mei LIU ; Meng Yu GUO ; Yan Ying REN ; Yi Fan LI ; Yong Wei LI
Chinese Journal of Preventive Medicine 2023;57(8):1222-1230
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*
6.Molecular epidemiology of clinical isolation of carbapenem-resistant Enterobacterales and application of carbapenemase inhibitor enhancement test.
Hongling LI ; Yiming ZHONG ; Qun YAN ; Wen'en LIU ; Xianghui LIANG
Journal of Central South University(Medical Sciences) 2023;48(8):1210-1216
OBJECTIVES:
The prevalence of carbapenem-resistant Enterobacterales (CRE) presents a significant challenge in clinical anti-infective treatment. This study aims to investigate drug resistance and the molecular epidemiological characteristics of CRE in our area. Additionally, we seek to evaluate practicality of utilizing carbapenemase inhibitor enhancement test in clinical laboratory.
METHODS:
Non-repeated CREs isolated from clinical specimens at Xiangya Hospital, Central South University, were collected. Minimum inhibitory concentration (MIC) combined with Kirby-Bauer (KB) assay was used to detect the drug susceptibility of the strains, and 13 carbapenemase-producing genes were detected by PCR. The phenotype of 126 strains of carbapenemase-producing Enterobacterales identified by PCR was detected by the carbapenemase inhibitor enhancement test to understand the agreement between the method and the gold standard PCR results.
RESULTS:
Among 704 CRE strains examined, we observed significant drug resistance in 501 strains dentified as carbapenemase-producing Enterobacterales (CPE). Klebsiella pneumoniae was the predominant CPE strain, followed by Enterobacter cloacae and Escherichia coli. A total of 9 carbapenemase types were detected, including Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron- encoded metallo-β-lactamases (VIM), imipenemase (IMP), oxacillinase-48 (OXA-48), and rare imipenem-hydrolyzing β-lactamase (IMI), adelaide imipenemase (AIM), Bicêtre carbapenemase (BIC), and guiana extended-spectrum β-lactamase (GES). The detection rate of KPC serine carbapenemase was 61.7% (309/501). The carbapenemase inhibitor enhancement test exhibited a 100% consistency rate for the strains producing Class A serine carbapenemase and/or Class B metallo-β-lactamases.
CONCLUSIONS
CRE strains in Changsha, Hunan, China, are wide distribution and exhibit carbapenemase production. The main mechanism of carbapenem resistance in these bacterias is predominatly attributed to the production of KPC serine carbapenemase. The presence of GES and IMI genes carried by Enterobacterales has been detected for the first time in this region. The carbapenemase inhibitor enhancement test has been proven to be an accurate method for detecting CRE producing Class A serine carbapenemase and/or Class B metallo-β-lactamases. This method offers simpicity of operation and ease of results interpretation, making it weel-suited meeting the clinical microbiology laboratory's reguirements for the detection of serine carbapenemase and metallo-β-lactamases.
Humans
;
Carbapenems/pharmacology*
;
Molecular Epidemiology
;
Bacterial Proteins/analysis*
;
beta-Lactamases/analysis*
;
Klebsiella pneumoniae/genetics*
;
Escherichia coli
;
Microbial Sensitivity Tests
;
Serine
;
Anti-Bacterial Agents/pharmacology*
7.UhpTE350Q mutation along with the presence of fosA6/5 genes in the genome probably contributes to inherent fosfomycin resistance of Klebsiella pneumoniae.
Rong DA ; Yi ZHOU ; Yue CHENG ; Jia LV ; Bei HAN
Journal of Southern Medical University 2023;43(7):1110-1115
OBJECTIVE:
To investigate the molecular mechanism underlying inherent fosfomycin resistance of Klebsiella pneumoniae (K. pneumoniae).
METHODS:
The draft genomic sequences of 14 clinical hypervirulent/hypermucoviscous K. pneumoniae (HvKP/ HmKP) isolates were obtained using the next-generation sequencing technology. The genomic sequences were analyzed using the Resistance Gene Identifier (RGI) software for predicting the resistome based on homology and SNP models in the Comprehensive Antibiotic Resistance Database (CARD) and for identification of the presence of phosphomycin resistancerelated genes uhpt and fosA and their mutations in the bacterial genomes. The results were verified by analyzing a total of 521 full-length genomic sequences of K. pneumonia strains obtained from GenBank.
RESULTS:
All the 14 clinical isolates of HvKP/ HmKP carried hexose phosphate transporter (UhpT) gene mutation, in which the glutamic acid was mutated to glutamine at 350aa (UhpTE350Q mutation); the presence of fosA6 gene was detected in 12 (85.71%) of the isolates and fosA5 gene was detected in the other 2 (14.29%) isolates. Analysis of the genomic sequences of 521 K. pneumonia strains from GenBank showed that 508 (97.50%) strains carried UhpTE350Q mutation, 439 (84.26%) strains harbored fosA6, and 80 (15.36%) strains harbored fosA5; 507 (97.31%) strains were found to have both UhpTE350Q mutation and fosA6/5 genes in the genome. Only 12 (2.30%) strains carried fosA6/5 genes without UhpTE350Q mutation; 1 (0.19%) strain had only UhpTE350Q mutation without fosA6/5 genes, and another strain contained neither UhpTE350Q mutation nor fosA6/5 genes.
CONCLUSION
UhpTE350Q mutation with the presence of fosA6/5 genes are ubiquitous in K. pneumonia genomes, indicating a possible intrinsic mechanism of fosfomycin resistance in the bacterium to limit the use of fosfomycin against infections caused by K. pneumoniae, especially the multi-resistant HvKP/HmKP strains.
Fosfomycin
;
Klebsiella pneumoniae
;
Mutation
;
Databases, Factual
;
High-Throughput Nucleotide Sequencing
8.Analysis of fast-growing culturable bacteria and pathogenic bacteria in the surface water of the northeast coast of Hainan Island in China.
Mei XING ; Qiu Ye FU ; Si Si LIN ; Xiong FU ; Xiao Xia WANG ; Li Cheng WANG ; Xiong ZHU ; Ting Lan OUYANG
Chinese Journal of Preventive Medicine 2023;57(8):1206-1216
Objective: To obtain the diversity and abundance of fast-growing bacteria in the surface water of the northeast coast of Hainan Island in China, different cultivation methods were employed. This study also aims to provide a reference for isolating bacterial samples from seawater sources and preventing marine-derived pathogens. Methods: Based on the principles of taxonomic design, surface seawater samples were collected from six locations along the northeast coast of Hainan Island in China in March, June, October, and December 2021. Then, bacterial enrichment was performed based on traditional cultivation methods for Salmonella, Vibrio, Burkholderia pseudomallei, Actinomycetes, and general marine bacteria. After that, bacterial species identification was conducted by 16S rDNA amplicon sequencing and metagenomic sequencing. Results: A total of 1 151 fast-growing cultivable bacteria belonging to 66 genera and 213 species were identified using five different culture protocols. In different cultivation protocols, Bacillus and Klebsiella demonstrated extensive discriminatory advantages and ranked among the top genera in terms of abundance. Protocol 1 had Escherichia, Klebsiella, and Citrobacter as dominant genera. Pathogenic bacteria detected by protocol 1 included Klebsiella pneumoniae and Escherichia coli, with 37 and 29 strains respectively, while Salmonella enterica was uniquely detected with seven isolates. Proteus, Enterococcus, and Providencia were the dominant genera in protocol 2, and Proteus mirabilis was the most abundant pathogenic bacteria detected with 66 isolates. Vibrio cholerae was uniquely detected with six isolates at a higher abundance. Klebsiella, Escherichia, and Acinetobacter were the dominant genera in protocol 3, and Klebsiella pneumoniae was the most abundant pathogenic bacteria detected with 53 isolates, while Acinetobacter nosocomialis was uniquely detected with seven isolates. Vibrio and Pseudoalteromonas were the dominant genera in protocol 4, and they showed advantages in isolating and cultivating Marine-derived Vibrio. Exiguobacterium, Staphylococcus, and Bacillus were the dominant genera in protocol 5. Bacillus cereus and Lactococcus lactis were the most abundant pathogenic bacteria detected with 20 and 15 isolates, respectively, while Lactococcus lactis was uniquely detected at higher abundance. Metagenomic sequencing showed that Klebsiella pneumoniae was significantly dominant with a gene abundance of 51.11%, followed by Alcanivorax sp. at 12.57%. Conclusion: The surface water of the northeast coast of Hainan Island in China exhibits a rich diversity of bacteria, with Klebsiella pneumoniae being highly abundant in the studied area. Different cultivation methods demonstrate distinct selective advantages in culturing bacterial genera and pathogens. Therefore, it is necessary to optimize cultivation conditions for specific marine bacteria.
Humans
;
Water
;
Bacteria/genetics*
;
Seawater/microbiology*
;
Escherichia coli
;
Enterococcus
;
Klebsiella pneumoniae
;
China
9.Molecular epidemiological characterization of hypervirulent carbapenem-resistant Klebsiella pneumoniae in a hospital in Henan Province from 2020 to 2022.
Xin Wei LIU ; Deng Zhou LI ; Yue HU ; Rui ZHU ; Dong Mei LIU ; Meng Yu GUO ; Yan Ying REN ; Yi Fan LI ; Yong Wei LI
Chinese Journal of Preventive Medicine 2023;57(8):1222-1230
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*
10.Clinical Outcome and Risk Factors of Treatment Failure of Peritoneal Dialysis Associated Peritonitis Caused by Klebsiella Pneumoniae:A Multicenter Study.
Hui-Zhi YUAN ; Xue-Yan ZHU ; Li-Ming YANG ; Xiao-Xuan ZHANG ; Xin-Yang LI ; Tong XIE ; Jing-Zhu ZHAI ; Xiao-Hua ZHUANG ; Wen-Peng CUI
Acta Academiae Medicinae Sinicae 2023;45(2):227-234
Objective To investigate the treatment outcomes,prognosis,and risk factors of treatment failure of peritoneal dialysis associated peritonitis (PDAP) caused by Klebsiella pneumoniae,and thus provide clinical evidence for the prevention and treatment of this disease. Methods The clinical data of PDAP patients at four peritoneal dialysis centers from January 1,2014 to December 31,2019 were collected retrospectively.The treatment outcomes and prognosis were compared between the patients with PDAP caused by Klebsiella.pneumoniae and that caused by Escherichia coli.Kaplan-Meier method was employed to establish the survival curve of technical failure,and multivariate Logistic regression to analyze the risk factors of the treatment failure of PADP caused by Klebsiella pneumoniae. Results In the 4 peritoneal dialysis centers,1034 cases of PDAP occurred in 586 patients from 2014 to 2019,including 21 cases caused by Klebsiella pneumoniae and 98 cases caused by Escherichia coli.The incidence of Klebsiella pneumoniae caused PDAP was 0.0048 times per patient per year on average,ranging from 0.0024 to 0.0124 times per patient per year during 2014-2019.According to the Kaplan-Meier survival curve,the technical failure rate of Klebsiella pneumoniae caused PDAP was higher than that of Escherichia coli caused PDAP (P=0.022).The multivariate Logistic regression model showed that long-term dialysis was an independent risk factor for the treatment failure of Klebsiella pneumoniae caused PDAP (OR=1.082,95%CI=1.011-1.158,P=0.023).Klebsiella pneumoniae was highly sensitive to amikacin,meropenem,imipenem,piperacillin,and cefotetan,and it was highly resistant to ampicillin (81.82%),cefazolin (53.33%),tetracycline (50.00%),cefotaxime (43.75%),and chloramphenicol (42.86%). Conclusion The PDAP caused by Klebsiella pneumoniae had worse prognosis than that caused by Escherichia coli,and long-term dialysis was an independent risk factor for the treatment failure of Klebsiella pneumoniae caused PDAP.
Humans
;
Klebsiella pneumoniae
;
Retrospective Studies
;
Anti-Bacterial Agents/therapeutic use*
;
Peritoneal Dialysis/adverse effects*
;
Peritonitis/drug therapy*
;
Risk Factors
;
Treatment Failure
;
Escherichia coli

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