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Objective To understand the distribution of frequently isolated pathogenic bacteria from clinical speci-mens and their antimicrobial resistance changes in Hunan Province from 2012 to 2021,and to provide scientific evi-dence for the formulation and evaluation of antimicrobial clinical administration policies.Methods Species identifi-cation,selection of quality control strains and antimicrobial susceptibility testing agents were conducted according to the technical scheme of the China Antimicrobial Resistance Surveillance System(CARSS).Duplicate strains were excluded based on the principle of counting the first strain in each case.Statistical analysis was performed by WHO-NET 5.6 software.The the variations in constituent ratio and resistance rate of strains were analyzed with linear trend test,and the magnitude of change was described with Pearson correlation coefficient.Results From 2012 to 2021,the number of clinically isolated bacteria in the analysis increased from 82 759 to 312 914,with Gram-negative bacteria accounting for 69.5％-72.4％.The major Gram-positive bacteria were Staphylococcus aureus,Staphylo-coccus epidermidis,Streptococcus pneumoniae,Enterococcus faecalis and Enterococcus faecium,and the major Gram-negative bacteria were Escherichia coli,Klebsiella pneumoniae,Pseudomonas aeruginosa,Acinetobacter baumannii and Enterobacter cloacae.Isolation rate of Gram-positive bacteria increased yearly(r=0.022,P=0.001).Isolation rate of methicillin-resistant Staphylococcus aureus(MRSA)decreased from 34.3％to 24.8％.Isolation rates of vancomycin-resistant Enterococcus faecium and Enterococcus faecalis were less than 3％and 2％,respectively,presenting a downward trend.The detection rate of penicillin-resistant Streptococcus pneumoniae(PRSP)decreased from 5.6％to 1.0％.Except cefoperazone sulbactam,resistance rates of Escherichia coli to other tested antimicrobial agents showed decreasing trends(r＜0,P=0.001).Isolation rates of third-generation cephalo-sporin-resistant Escherichia coli(CTX/CRO-R-EC)and carbapenem-resistant Escherichia coli(CREC)decreased year by year(from 70.5％to 45.3％,and 12.2％to 2.0％,respectively).Resistance rates of Klebsiella pneumo-niae to imipenem and meropenem have increased year by year,reaching 9.1％and 11.0％respectively in 2021,while isolation rate of carbapenem-resistant Pseudomonas aeruginosa(CRPA)decreased from 28.5％to 15.0％.Resistance rates of Acinetobacter baumannii to most antimicrobial agents were 40％-60％,and remained relatively stable.Isolation rate of carbapenem-resistant Acinetobacter baumannii(CRAB)ranged from 39.5％ to 59.6％.Conclusion The clinical isolation rates of most important special antimicrobial-resistant bacteria have been decrea-sing year by year,while the resistance rate of Klebsiella pneumoniae to carbapenem agents gradually increased.Antimicrobial stewardship as well as the prevention and control of healthcare-associated infection on specific antimi-crobial-resistant bacteria should continue to be implemented in the future.The coverage and quality of antimicrobial resistance surveillance in H unan Province should continue to be improved.
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Objective To understand the distribution and antimicrobial resistance changes of bacteria isolated from pleural and peritoneal effusion in Hunan Province,and provide reference for correct clinical diagnosis and rational antimicrobial use.Methods Data reported by member units of Hunan Provincial Antimicrobial Resistance Survei-llance System from 2012 to 2021 were collected.Bacteria antimicrobial resistance surveillance method was imple-mented according to technical scheme of China Antimicrobial Resistance Surveillance System(CARSS),and WHO-NET 5.6 software was used to analyze the data of bacteria isolated from pleural and peritoneal effusion as well as antimicrobial susceptibility testing results.Results From 2012 to 2021,a total of 28 934 bacterial strains were iso-lated from specimens of pleural and peritoneal effusions from member units of Hunan Provincial Antimicrobial Re-sistance Surveillance System,with 5 752 strains from pleural effusion and 23 182 from peritoneal effusion.The top five bacteria isolated from pleural effusion were Escherichia coli(n=907,15.8％),Staphylococcus aureus(n=535,9.3％),Klebsiella pneumoniae(n=369,6.4％),Staphylococcus epidermidis(n=452,7.9％),and Staphy-lococcus haemolyticus(n=285,5.0％).The detection rate of methicillin-resistant Staphylococcus aureus(MR-SA)from pleural effusion was 24.3％-39.2％,and that of methicillin-resistant coagulase negative Staphylococcus(MRCNS)was 58.8％-77.1％.The top five bacteria isolated from peritoneal effusion were Escherichia coli(n=8 264,35.6％),Klebsiella pneumoniae(n=2 074,9.0％),Enterococcus faecium(n=1 458,6.3％),Staphylo-coccus epidermidis(n=1 383,6.0％),and Pseudomonas aeruginosa(n=1 152,5.0％).The detection rate of MRSA from peritoneal effusion was 22.1％-52.4％,which presented a decreasing trend(P=0.004).The detec-tion rate of MRCNS was 60.4％-79.4％.The resistance rates of Enterobacterales from peritoneal effusion to ce-fazolin,cefuroxime,ceftriaxone and cefepime all showed decreasing trends(all P＜0.05).Vancomycin-,linezo-lid-,and teicoplanin-resistant Staphylococcus strains were not found in pleural and peritoneal effusions.The resis-tance rates of Enterococcus faecium to most tested antimicrobial agents were higher than those of Enterococcus fae-calis.The resistance rates of Enterobacterales to imipenem and meropenem were ≤8.5％.The resistance rates of non-fermentative Gram-negative bacilli to imipenem and meropenem were ≤43.3％.Conclusion The data structure of Hunan Antimicrobial Resistance Surveillance System for pleural and peritoneal effusions from 2012 to 2021 is relatively complete.The constituent and antimicrobial susceptibility of isolated pathogenic bacteria vary in different years.
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Objective To understand the distribution and changes in antimicrobial resistance of clinically isolated Pseudomonas aeruginosa(P.aeruginosa)in the member hospitals of Hunan Provincial Antimicrobial Resistance Surveillance System from 2012 to 2021.Methods Antimicrobial susceptibility testing by disk diffusion or automa-ted instrument was performed on clinical isolates.Testing results were determined according to the standards of 2022 edition from American Clinical Laboratory Standards Institute(CLSI).Statistical analysis was performed by WHONET 5.6 software.Data were analyzed by trend test(Cochran-armitage)and Chi-square test with SPSS.Results A total of 176 441 strains of P.aeruginosa were surveilled by Hunan Provincial Antimicrobial Resistance Surveillance System from 2012 to 2021.99.4％of the strains were isolated from hospitalized patients,and about 70％of the strains were isolated from respiratory specimens.8.4％of P.aeruginosa were from children(0-17 years old),91.6％were from adults.Antimicrobial susceptibility testing results showed that P.aeruginosa was most sensitive to polymyxin B over 10 years,with a resis-tance rate of less than 6％.Resistance rates to piperacil-lin,piperacillin/tazobactam,ceftazidime,cefepime,aztreonam,imipenem,amikacin,gentamicin,tobramycin,cip-rofloxacin,levofloxacin,and polymyxin B all showed downward trends.A total of 29 920 carbapenem-resistant P.aeruginosa(CRPA)strains were detected.The average isolation rate of CRPA in this province was 18.0％over 10 years.CRPA detection rate from adult was 18.5％,higher than that from children(12.3％),and both showing downward trends.Conclusion The resistance rate of clinically isolated P.aeruginosa in Hunan Province to most commonly used antimicrobial agents is decreasing.
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Objective To understand the epidemiology of clinically isolated Acinetobacter baumannii(A.bauma-nnii)in Hunan Province.Methods Bacterial antimicrobial resistance surveillance was carried out according to the requirements of the technical program of National Antimicrobial Resistance Surveillance System.Clinical data of Acinetobacter spp.reported to Hunan Provincial Antimicrobial Resistance Surveillance System by multiple centers in Hunan Province from 2012 to 2021 were summarized and analyzed with reference to the standards of the American Clinical and Laboratory Standards Institute.Results A total of 169 438 strains of Acinetobacter spp.were detected during the 10-year period,with the detection rate of A.baumannii being the highest(82.74％).70 923 strains(53.63％)of carbapenem-resistant A.baumannii(CRAB)and 58 149 strains(43.97％)of carbapenem-sensitive A.baumannii(CSAB)were detected respectively.Both CRAB and CSAB were detected most frequently in the age group＞70 years,which were 34.44％and 32.02％,respectively.The percentage of CRAB and CSAB detected in the intensive care unit were 34.80％and 11.31％,respectively.CRAB and CSAB were mainly isolated from spu-tum/bronchoalveolar lavage fluid,followed by pus/secretion,urine,and blood.The resistance rates of CRAB to commonly used antimicrobial agents didn't change much during the 10-year period.Resistance rates of CRAB to ceftazidime and cefepime were both＞84％,to ampicillin/sulbactam and piperacillin/tazobactam were both＞82％,to aminoglycosides and quinolones were both＞59％,to minocycline and polymyxin B were 15.9％-25.0％and 1.3％-6.9％,respectively.CSAB were sensitive to commonly used antimicrobial agents.Conclusion The isolation rate of CRAB is high and there is no significant change in resistance to commonly used antimicrobial agents.
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<p><b>OBJECTIVE</b>To investigate the characteristics of New Delhi metallo-beta-lactamase-1 (NDM-1) gene of Klebsiella pneumoniae (K. pneumoniae) emerging in Hunan, and its relationship to antibiotic resistance.</p><p><b>METHODS</b>The clinical strain was isolated from a sputum sample of a child with severe pnemonia and toxic myocarditis who was admitted into a general hospital of Hunan Province. VITEK-2 compact instrument was used for bacterial identification and antibiotic susceptibility test. Modified Hodge test was used for the screening of carbapenemase. EDTA-synergy test and combination disk diffusion test were used for detection of metallo-β-lactamase (MBL). PCR was performed for amplification of NDM-1 genes and the positive products were sequenced and analyzed with BLAST. Conjugation was also performed to analyze mechanisms of antibiotic resistance. The results of antibiotic susceptibility tests were compared before and after conjugation.</p><p><b>RESULTS</b>The isolated strain was identified as K.pneumoniae. Modified Hodge test, EDTA-synergy test and combination disk diffusion test were all positive for the strain. The homology between gene sequence of PCR amplification products and NDM-1 gene FN396876.1 in the GenBank was 100%. Transconjugant DNA was used as template for the amplification of NDM-1 gene. The amplification products were sequenced and found to be the same as the NDM-1 gene amplification product of the donor strain. The MIC of transconjugant E.coli J53 (NDM-1) to all the β-lactams increased significantly compared with the recipient strain E.coli J53. The MIC of ertapenem and imipenem increased by more than 8 times, while the MIC of ceftazidime and ceftriaxone increased by more than 64 times.</p><p><b>CONCLUSIONS</b>This study first identified a strain of K. pneumoniae carrying NDM-1 in mainland China. NDM-1 gene can be transmitted among different strains and causes extensively drug-resistance to β-lactams.</p>
Subject(s)
Base Sequence , China , Drug Resistance, Bacterial , Klebsiella pneumoniae , Genetics , Molecular Sequence Data , Polymerase Chain Reaction , beta-Lactamases , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To study the pharmacokinetic of 10-Hydroxycamptothecin HCPT by intraperitoneal administration.</p><p><b>METHOD</b>Six dogs were given HCPT by intraperitoneal perfusion: HCPT 2 mg x kg(-1), dissolved in 300 mL NS. During the course of experiments, peritoneal fluids and blood were sampled using a standardized protocol. The concentration of HCPT in all samples was determined by high performance liquid chromatography (HPLC).</p><p><b>RESULT</b>The area under the curve (AUC) of peritoneal fluids was significantly highly as compared to the AUC of femoral vein and portal vein (P < 0.001).</p><p><b>CONCLUSION</b>These experiments demonstrate that intraperitoneal chemotherapy has significant effect on the pharmacokinetics of IP route of HCPT administration. This method should be a more reasonable chemotherapy for the prevention of recurrence and liver metastasis of gastric cancer, colon cancer and ovary cancer after radical resection.</p>