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OBJECTIVE:To provide reference for rational drug use and hospital infection control. METHODS:AmpC enzyme-producing Enterobacter cloacae were isolated from non-sputum specimen of a hospital during Jan. 2011-Oct. 2017. Drug sensitivity test was conducted by using MIC. The situation of AmpC enzyme production was confirmed by three dimensional test, and that of ESBLs-producing stain was detected with double-disk synergy test. RESULTS:There were 546 strains of AmpC enzyme-producing E. cloacae isolated from non-sputum specimen of the hospital,accounting for 4.80% of non-sputum specimen (546/11 375)and 38.97% of E. cloacae(546/1 401). Top 3 non-sputum samples in the list of detection rate were wound secretion (27.29%),midstream urine(25.82%)and blood(21.79%),and the departments with high detection rate were ICU(22.89%), neurosurgery department(18.68%)and general surgery department(16.67%). Resistance rate of AmpC enzyme-producing E. cloacae to most commonly used antibiotics was higher than 40%. There was statistical significance in resistant rate of the bacteria to ceftriaxone, cefotaxime, gentamicin, nitrofurantoin, levofloxacin, piperacillin/tazobactam, cefoperazone, ceftazidime,cefepime,tobramycin and minocycline among different years (P<0.05). The resistant rate to imipenem and meropenem was lower than 2%. Among 546 strains of AmpC enzyme-producing E. cloacae,68 strains of ESBLs were detected,and detection rates were 5.77%,6.06%,8.70%,10.26%,13.79%,17.35%,18.75% during 2011-2017. CONCLUSIONS:AmpC enzyme-producing E. cloacae are mainly isolated from samples as wound secretion and midstream urine,and mainly come from ICU and neurosurgery department. The drug resistance of the bacteria is severe,and drug resistance of the bacteria to antibiotics as β-lactams and quinolones is increased significantly. The detection rate of ESBLs-producing strain increases year by year. The bacteria are sensitive to carbapenems antibiotics,which can be regarded as first choice. It is necessary to strengthen drug resistance and enzyme production monitoring of AmpC enzyme-producing E. cloacae,select antibiotics combined with results of drug sensitivity test so as to prevent or delay the rapid increase of its resistance rate.
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Objective To construct mutant strains of Klebsiella pneumoniae with ampG gene dele-tion by homologous recombination and to evaluate the role of ampG gene in inducing the expression of AmpC enzyme.Methods Polymerase chain reaction ( PCR) was used to amplify the upstream and downstream fragments of ampG gene.The gene splicing by overlap extension PCR ( SOE-PCR) technique was used to construct the fusion fragment , which was then ligated into the temperature sensitive suicide vector pKO 3-km after enzyme digestion as pKO3-km-ΔampG.To achieve allelic exchange , the plasmid pKO3-km-ΔampG was introduced into Kp1 and Kp NTUH-K2044 strains by electroporation .The mutant strains of Klebsiella pneu-moniae with ampG gene deletion were screened out .The plasmid pACYC184-ampCR was introduced into the Kp NTUH-K2044 wild-type strain and its mutant strain with ampG gene deletion to make them harbor the gene encoding AmpC enzyme .The disk diffusion method was used to evaluate the effects of ampG gene on the expression of AmpC enzyme in Klebsiella pneumoniae strains with cefoxitin as the inducer .Results The recombinant plasmid pKO3-km-ΔampG was constructed successfully .The mutant strains of Klebsiella pneu-moniae with ampG gene deletion were constructed as verified by PCR and DNA sequencing .Compared with the Kp1 wild type strain, no AmpC enzyme was produced by the ampG gene knock-out Kp1 strain.The Kp NTUH-K2044 strain could produce AmpC enzyme , while the mutant strain of Kp NTUH-K2044 with ampG gene deletion could not after introduced the pACYC 184-ampCR plasmid .Conclusion The mutant strain of Klebsiella pneumoniae with ampG gene deletion was successfully constructed .The Klebsiella pneumonia strain without the ampG gene could not produce the AmpC enzyme .
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Objective To investigate the prevalence and molecular characteristics of the extended -spectrum β-lactamase ( ESBL) and AmpC enzyme-producing Proteus mirabilis ( P.mirabilis) strains isola-ted in Shenzhen People′s Hospital.Methods The production of ESBLs and AmpC enzymes by P.mirabilis isolates were detected by a screening and confirmatory test for ESBLs and AmpC disk test , respectively .The PCR assays followed by DNA sequencing of the products were employed to analyze the multiple genes inclu -ding the ESBLs genes, AmpC genes, insertion sequences (ISs) upstream of the ESBLs or AmpC genes, plasmid -mediated quinolone resistance ( PMQR ) determinants , quinolone resistance-determining region (QRDR) genes , the integrase genes, and class1 integron cassette.The epidemiological analysis of the iso-lates was performed by pulsed field gel electrophoresis .Results There were 130 P.mirabilis clinical iso-lates collected from Shenzhen People′s Hospital in China during the year 2004 to 2010.Among them, 13 isolates (10%) produced ESBLs, that accounted for 0%-9.1%in the year 2004-2009 and up to 29.4%in 2010, and 3 isolates (2.3%) produced AmpC enzymes.The predominant genotype of ESBLs -producing isolateswas b al CTX-M-14(n=7), followed by blaCTX-M-65(n=3), blaCTX-M-55(n=1), blaCTX-M-24(n=1) and blaPER-1 (n =1).The clinical isolate of PER-1-producing P.mirabilis was reported for the first time in China.Twoisolates carried an AmpC β-lactamase gene of blaCMY-2 and one isolate carried an unidentified AmpC gene .ISEcp1 located upstream of blaCTX-M and blaCMY-2 were detected in 91.7% (11/12) of CTX-M-producing isolatesand one CMY-2-producing isolate, respectively.ISPa12 was present upstream of blaPER-1 in one studiedisolate.Approximately 66.7% (10/15) of ESBL and /or AmpC-producing isolates harbored PMQR genes including2 carrying qnrD, 5 carrying aac-Ib-cr and 3 carrying both qnrD and aac-Ib-cr.Twelve ESBL and /orAmpC-producers with high level of resistance to ciprofloxacin carried the similar mutation profiles of S 83I inGyrA, S80I or S80R in ParC and among them, six strains showed E466D mutation in GyrB.Approximately86.7% (13/15) of ESBL and/or AmpC-producing isolates carried class 1 integron.Fourteen PFGE typeswere observed among 15 ESBL and/or AmpC-producers.Conclusion The prevalence of CTX-M β-lactamasesin P.mirabilis isolates contributed to the increased resistance to extended -spectrum cephalosporins.The qnrD and/or aac-Ib-cr genes were detected among the most of ESBL and /or AmpC-producing P.mirabilis clinical isolates.
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Background & objectives: AmpC β-lactamases are clinically significant since these confer resistance to cephalosporins in the oxyimino group, 7-α methoxycephalosporins and are not affected by available β-lactamase inhibitors. In this study we looked for both extended spectrum β-lactamases (ESBL) and AmpC β-lactamases in Klebsiella pneumoniae clinical isolates. Methods: One hundred consecutive, non-duplicate clinical isolates of K. pneumoniae collected over a period of one year (June 2008 - June 2009) were included in the study. An antibiotic susceptibility method was used with 10 antibiotics for Gram-negative infections which helped in screening for ESBL and AmpC β-lactamases and also in confirmation of ESBL production. The detection of AmpC β-lactamases was done based on screening and confirmatory tests. For screening, disc diffusion zones of cefoxitin <18 mm was taken as cefoxitin resistant. All cefoxitin resistant isolates were tested further by AmpC disk test and modified three dimensional test. Multiplex-PCR was performed for screening the presence of plasmid-mediated AmpC genes. Results: Of the 100 isolates of K. pneumoniae studied, 48 were resistant to cefoxitin on screening. AmpC disk test was positive in 32 (32%) isolates. This was also confirmed with modified three dimensional test. Indentation indicating strong AmpC producer was observed in 25 isolates whereas little distortion (weak AmpC) was observed in 7 isolates. ESBL detection was confirmed by a modification of double disk synergy test in 56 isolates. Cefepime was the best cephalosporin in synergy with tazobactam for detecting ESBL production in isolates co-producing AmpC β-lactamases. The subsets of isolates phenotypically AmpC β-lactamase positive were subjected to amplification of six different families of AmpC gene using multiplex PCR. The sequence analysis revealed 12 CMY-2 and eight DHA-1 types. Interpretation & conclusions: Tazobactam was the best β-lactamase inhibitor for detecting ESBL in presence of AmpC β-lactamase as this is a very poor inducer of AmpC gene. Amongst cephalosporins, cefepime was the best cephalosporin in detecting ESBL in presence of AmpC β-lactamase as it is least hydrolyzed by AmpC enzymes. Cefepime-tazobactam combination disk test would be a simple and best method in detection of ESBLs in Enterobacteriaceae co-producing AmpC β-lactamase in the routine diagnostic microbiology laboratories.
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Bacterial Proteins/isolation & purification , Cefoxitin , Drug Resistance, Bacterial , Klebsiella pneumoniae/isolation & purification , Humans , India , Penicillanic Acid/analogs & derivatives , beta-Lactamases/isolation & purificationABSTRACT
OBJECTIVE To analyze the situation of extended spectrum ?-lactamases(ESBLs)and AmpC enzyme produced by nosocomial Escherichia coli isolates in 2005-2007.METHODS ESBLs were detected by double disk synergy test and disk diffusion confirmatory test.AmpC enzyme was detected by the three dimensional assay.Chi square test was used to test the significance.The application of different kinds of antimicrobials before the results of etiology be presented and the resistence rate of the ESBLs both producing and no producing were compared respectively.RESULTS The detectable rate of ESBLs in E.coli isolates of nosocomial and community infection was 55.1% and 21.3% and the detectable rate of AmpC enzyme nosocomial E.coli isolates was 17.4%.All strains were 100% susceptible to meropenem and imipenem but resistant to 15 other antimicrobials in different degree.The sensitivity to Piperacillin/tazobactam,cefoperazone/sulbactam and amikacin were relatively high.CONCLUSIONS The carrying rate of ESBLs from nosocomial E.coli isolates is high and AmpC enzyme and other resistance genes,which lead to multiple drug resistance.Standardized management of antimicrobials application should be strengthened and the consciousness of rational antimicrobials utilization should be raised.
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OBJECTIVE To study the isolation,distributive characteristics and drug resistance of AmpC enzyme producing Gram-negative bacilli in nosocomial infection of two years and provide the evidence for treatment. METHODS A total of 528 strains of Gram-negative bacilli collected from daily specimens were identified with Bio-Fosun-Ⅰ,and AmpC enzyme was screened by cefoxitin disk and then corroborated by EDTA disk method. All data were analyzed statistically. RESULTS Among 528 strains collected,136 (25.75%) were AmpC enzyme producing strains,the respective percentage of Pseudomonas aerugionsa,Echerichia coli,Enterobacter cloacae,Klebsiella pneumoniae and Citrobacter was 32.35%,28.67%,18.38%,8.09% and 5.15%,respectively. Most strains (38.9%) were detected in ICU. The common infection sites were lungs. The resistance rate of AmpC enzyme producing strains to the first,second and third-generations cephalosporins was 71.3-99.5%. The susceptive rate of AmpC enzyme producing strains to imipenem,cefepine,amikacin and piperacillin/tazobactant were low. CONCLUSIONS For effective supervision and control of AmpC enzyme producing Gram-negative bacilli in nosocomial infection,detection of AmpC enzyme shoud be paid much attention by clinical microbiology laboratory.
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Objective To investigate the genetic features related to drug-resistance of a strain of pan-drug resistant Acinetobacter baumannii. Methods The susceptibilities to 15 antibacterial agents were detected in Acinetobacter baumannii by K-B paper diffusing method. A strain of pan-drug resistant Acinetobacter baumannii was selected. The drug-resistant genes of the selected strain were amplified by polymerase chain reaction (PCR) , including 15 extended-spectrum β-lactamase genes, 3 metal β-lactamase genes, 2 AmpC enzyme genes, 7 aminoglycoside modifying enzyme genes and the genetic markers of integron I and transposons. Results The strain was resistant to 14 antibacterial agents except cefoperazone sodium/ sulbactam. β-lactamases genes ( TEM, OXA-23 and ADC) , aminoglycosides modification enzyme genes [aac(3)- I , aac(6')- I b and ant(3")- I ] , integron I qacEAi-sull and transposon tnpU were positive in PCR amplification. A new subtype of AmpC (chromosome) desoxyribonucleic acid ( DNA) was detected. Conclusion Acinetobacter baumannii is of high resistance to most antibacterial agents, and the mechanisms of the resistance are complex.
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OBJECTIVE To investigate the distribation of the AmpC enzyme in Acinetobacter baumannii isolated from burned patients. METHODS Susceptibility tests were used to detect antibiotic resistance to 20 kinds of antimicrobial drugs in 20 strains of A. baumannii isolated from burned patients, AmpC enzyme genes were detected by PCR and partial positive products were chosen to sequence. RESULTS Drug resistances to ?-lactam antibiotics in 20 strains of A. baumannii isolated from burned patients had exceeded 85% except levofloxacin or cefoperazone/sulbactam. Of ADC genes 95% were positive, but all DHA genes were negative. Through sequence and Blast analysis, partial ADC positive products were identical with that of EF546445. CONCLUSIONS The multidrug resistance of A. baumannii isolated from burned patients to ?-lactam antibiotics is serious. AmpC enzyme mediated by chromosome, ADC, prevails in A. baumannii isolated from burned patients.
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OBJECTIVE To study the drug resistance and ?-lactamases produced by Acinetobacter baumannii isolated from lower respiratory tract.METHODS The drug sensitivity was detected with K-B test,and the ESBLs producing strains and ?-lactamases strains were screened by double disk test and confirmed by the NCCLS confirmation test.RESULTS Patients mostly were old from RICU,and broad-spectrum antibiotic therapy was applied,with history of re-oxygenating,sputa extraction and invasive operation.Fifteen received mechanical ventilation.Results of drug sensitivity showed almost all were resistant to FOX and CFZ,more than 70 percent resistant to CXM and MEZ,IPM and SCF,less than 10 percent resistant to AMX/CLAV,CAZ and OXL.There were no strains showing drug resistance to IPM,CAZ/CA and SCF.Test showed 5 strains(16%)produced AmpC enzyme and 9 strains(29%)produced ESBLs enzyme.CONCLUSIONS Rate of drug resistance is high,so drug susceptibility test should be enforced to guide reasonably clinical applying antibiotics in order to prevent outbreaks.
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OBJECTIVE To detect AmpC ?-lactamases from isolates of extended spectrum ?-lactamases(ESBLs) positive Escherichia coli and Klebsiella pneumoniae,which were isolated from four hospitals in Hangzhou from 2005 to 2006,and to analyze the antimicrobial activity of clinically commonly used antibiotics in vitro.METHODS Amount of 324 ESBLs positive isolates including E.coli and K.pneumoniae were collected from Zhejiang Provincial People′s Hospital;1st Affiliated Hospital of Zhejiang University;2nd Affiliated Hospital of Zhejiang University and Hangzhou Traditional Chinese Medicine Hospital perspectivly.AmpC ?-lactamase was identified by disc screening testing and three dimensional test,and the genotypes of AmpC ?-lactamase were also determined by multiplex polymerase chain reaction(Multi-PCR).Minimal inhibitory concentrations(MICs) of ten clinically commonly used antibiotics were determined by agar dilution for AmpC ?-lactamases positive isolates,and the data were analyzed by WHONET 5.3.RESULTS AmpC ?-lactamase phenotype test revealed that 76 AmpC ?-lactamase positive isolates(23.5%) were identified among 324 ESBLs positive isolates of E.coli and K.pneumoniae from four hospitals in Huzhou.69.7% Of the AmpC ?-lactamase phenotype positive isolates were positively amplified by Multi-PCR.The value of MIC50 for carbapenem was lower 0.25 ?g/ml.We also found four carbapenem-resistant strains in this study.CONCLUSIONS We found that the incidence rate of AmpC ?-lactamase is high among the ESBLs producing E.coli and K.pneumoniae strains in Hangzhou.Carbapenem antibiotics have higher antimicrobial activity than other tested antibiotics.
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OBJECTIVE To investigate the drug-resistance of AmpC enzyme derepressing Enterobacter cloacae isolated from patients of respiratory department.METHODS Totally 364 strains of E.cloacae(162 strains from respiration department) collected from Jan 2001 to Dec 2006 were investigated to know their ward distribution,infection site and susceptibility test results.Three-dimensional tests were adopted to test AmpC lactamase.RESULTS Among the total 162 strains from respiration department,AmpC producers were 76 strains,accounting for 46.91%. Among the 202 strains from the other departments,however,AmpC producers were 36 strains,accounting for 17.82%.And drug-resistance of E.cloacae from respiration department was distinctly higher than that from the other departments.CONCLUSIONS E.cloacae from respiratory department has the higher isolating rate and drug-resistance rate.We should take effective measurement to contain nosocomial infections with E.cloacae.
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OBJECTIVE To study the resistance of plasmid mediated AmpC ?-lactamase in Pseudomonas aeruginosa,to detect and identify the AmpC genotype,and to provide the laboratory evidence for antibiotic reasonable application in clinics.METHODS Totally 108 strains of clinically isolated P.aeruginosa were determined antibiotic-resistant phenotype by K-B disc test,and cefoxitin three dimensional test was applied to screen AmpC positive strains.Plasmids were extracted from AmpC positive strains by SDS-alkali splitting technique.The depurated plasmid was used to amplify AmpC ?-lactamase genes by PCR.Positive PCR product was sequenced by Shanghai Sangon Biological Engineering Technology Company.Gene homology of PCR product with other index sample gene sequences was compared.RESULTS There were 28 strains producing AmpC enzyme among 108 P.aeruginosa strains.AmpC Producing P.areuginosa strains displayed multidrug-resistance to antibiotics and a new P.areuginosa strain producing plasmid mediated CMY-7 type AmpC enzyme was discoverd firstly.CONCLUSIONS Presented plasmid mediated AmpC enzyme and AmpC type ?-lactamases in P.aeruginosa are its important resistant mechanism to antibiotics.A strain producing type CMY-7 plasmid mediated AmpC enzyme is found firstly in China.
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Objective To establish and evaluate a modified disc screening test used for detecting AmpC enzyme in Escherichia coli and Klebsiella pneumoniae.Methods Of 164 strains of clinical isolation of Escherichia coli and 40 strains of Klebsiella pneumoniae resistant to the third cephalosporin, AmpC enzyme was detected by the modified disc screening test, three-dimensional extract test and multiplex PCR.Results Among the 164 isolates of Escherichia coli,AmpC enzyme-positive strains were 8,8 and 9 by the above 3 methods,respectively.At the same time,2 ESBLs-positive strains were found by the modified disc screening test in the 8 AmpC-enzyme positive strains.Among the 40 isolates of Klebsiella pneumoniae,2 strains of induced AmpC were identified by the modified disc screening test and multiplex PCR.Conclusion The modified disc screening test can not only detect AmpC-positive strains,but also the strains with induced AmpC and ESBLs.The modified disc screening test is a simple,rapid and practical method which can be used in clinical laboratories.
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OBJECTIVE To monitor the Enterobacter cloacae resistance in our hospital patients.METHODS Disk susceptibility tests were performed for detection of E.cloacae resistance to 10 antibiotics,Detection of(extended)-spectrum ?-lactamases and AmpC ?-lactamase was conducted by three-dimensional extract test.RESULTS Seventy four strains of E.cloacae were isolated from our hospital patients,its had high resistant rate to 9 antibiotics(from(40.5%) to 91.8%),Among 74 strains of E.cloacae,10 isolates(13.5%) were considered as AmpC enzyme producing,31 strains(41.89%) were ESBLs-producing,6 strains(8.1%) were producing both of them.Total detection of AmpC(?-lactamase),or the production of ESBLs,or both of them were 47 strains(63.5%).Only imipenem was effective for all E.cloacae.CONCLUSIONS For the serious infection induced by E.cloacae producing AmpC ?-lactamase or(ESBLs),imipenem is first choice of treatment.
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OBJECTIVE:To investigate the classification,structure and integron-mediated AmpC enzyme gene transfer of integron in 25 strains of AmpC enzymeproducing Escherichia coli. METHODS:Sensitivity of test strains to 20 kinds of antibiotics was tested by microdilution method. PCR and sequencing were performed on test strains to identify integrase gene(intI)and its location,the product of variable region of positive integrons(Int)respectively. RESULTS:Class ⅠintI were indentified in 20 strains (80%)of 25 strains Escherichia coli. The most drug resistance box cassettes were aadA5 and dfr17 and integory encoding AmpC gene cassette was not observed. CONCLUSION:Class Ⅰ integron resided in AmpC enzyme-producing Escherichia coli widely. The cause of drug resistance of integorn to aminoglycosides,sulfonamides,chloramphenicol is drug resistance gene cassette. Gene cassette does not play important role in integron-mediated antibiotic resistant gene transformation.
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OBJECTIVE To study the current status of the AmpC enzyme and ?-lactamases genes for multi-resistant Acinetobacter baumannii isolates in clinic in Nanjing.METHODS The samples of 20 multi-resistant A.baumannii isolates were collected from Jul 2007 to Oct 2007 from the patients in hospitals of Nanjing.To determine the sensitivity to the 11 antibacterials by using a broth induction method,and two kinds of AmpC enzyme genes and eighteen kinds of ?-lactamases genes of multi-resistant A.baumannii analyzed by polymerase chain reaction(PCR).RESULTS In all of the 20 A.baumannii isolates,the AmpC genes of chromosome type were found in 14 isolates(70.0%),there were the AmpC genes of plasmid type in 1 isolate(5.0%),the TEM genes in 12 isolates(60.0%),the SHV genes in 1 isolate(5.0%),CTX-M-1 genes in 2 isolates(10.0%),OXA-23 genes in 1 isolate(5.0%),and OXA-24 genes in 1 isolate(5.0%),respectively.The OXA-24 genes from No.9 isolate was the type of OXA-72 after DNA sequencing.The amino acid sequence translated by AmpC genes of chromosome type from No.16 and No.17 isolates was the new subtype.CONCLUSIONS The A.baumannii has not only TEM,VEB,GES,IMP,VIM,OXA-10 and OXA-23 genes,but also the type of chromosome and plasmid of AmpC,SHV,CTX-M-1 and OXA-24 genes in Nanjing.It is the first time that activity of AmpC enzyme and the genotype of chromosome and plasmid of AmpC enzyme for matching are tested at the same time.
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Objective To investigate the drug-resistance and distribution of 142 strains acinetobacter baumannii.Methods Drug-resistance test of acinetobacter baumannii strains was observed in 13 kinds of antibiotics.The drug sensitivity tests was performed by the method of Kirby-Bauer paper-diffusion with the standard of NCCLS.AmpC enzyme was examined by cefoxitin three dimension test and PCR amplification of ampC structure gene were studied.Results The main sources of specimen were sputum,wound secretion,urine and blood.The respiratory tract was a major site to the development of acinetobacter baumannii.Acinetobacter baumannii strain emerged mostly in the intensive care unites.The drug resistance to cefotaxime,ceftriaxome and aztreonam were high.PCR amplification showed that of 142 acinetobacter baumannii strains,23 strains had ampC structure gene which accounted for 16 2% total strains.The drug resistance of acinetobacter baumannii producing AmpC enzyme were significantly higher than those of non-producing AmpC.The best choice of treatment was imipenem.Conclusions Acinetobacter baumannii have higher multiple-antibiotic resistance,the finding prompting us to project prospective control strategies.
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OBJECTIVE To review and analyze the distribution and antimicrobial resistance of nosocomial Escherichia coli and Klebsiella pneumoniae.METHODS Disk diffusion test(Kirby-Bauer)was used for anti-microbial susceptibility.Extended spectrum ?-lactamases(ESBLs)were detected by double disk synergy test and disk diffusion confirmatory test.AmpC enzyme was detected by the three dimensional assay.RESULTS The positive rate of the production of ESBLs and AmpC enzyme was 34.6% and 5.0%,respectively.The production rate of both ESBLs and AmpC enzyme positive was 2.4%.Isolated rate of ESBLs-producing strains in sputum and urine of the inpatients in respiratory ward and urinary ward was higher than others.All strains were 100% susceptible to meropenem and imipenem but resistant to 15 other antimicrobials in different degrees.CONCLUSIONS The isolated rate of ?-lactamases-producing strains is increasing year by year.These strains are multi-drug resistant.Attention must be paid to their detection and surveillance.
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OBJECTIVE To explore the isolation,distributive characteristics and drug resistance of Acinetobacter baumannii producing AmpC enzyme in nosocomial infection.METHODS The distributive sections and infected parts of 42 A.baumannii strains in nosocomial infection were analyzed,and three dimensional test was used to(detect) AmpC enzyme.RESULTS Among them 18(42.86%) strains were AmpC positive.Among 40 strains of A.baumannii in non-nosocomial infection,6(15.00%) strains were AmpC positive.A.baumannii in nosocomial(infection) in clinical sections was mainly discovered in burn department,and the respiratory tract and skin soft tissue were the main infected sites(90%).The drug resistance in nosocomial infection was obviously higher than that of A.baumannii in non-nosocomial one.CONCLUSIONS The isolated rate and drug resistance rate of A.baumannii producing AmpC enzyme are rather high in nosocomial infection.It′s(neccessary) to take measures to prevent the nosocomial infection caused by A.baumannii.