1.In vitro activities of meropenem, imipenem and ofloxacin against aerobic gram-negative bacilli and gram-positive cocci.
Yunsop CHONG ; Kyungwon LEE ; Samuel Y LEE
Korean Journal of Infectious Diseases 1991;23(2):95-105
No abstract available.
Gram-Positive Cocci*
;
Imipenem*
;
Ofloxacin*
2.In vitro Susceptibility of Imipenem-resistant Pseudomonas aeruginosa against Piperacillin/tazobactam.
Korean Journal of Clinical Microbiology 2007;10(2):171-172
Minimal inhibitory concentrations (MICs) against piperacillin/tazobactam were determined on a total of 50 clinical isolates of imipenem resistant Pseudomonas aeruginosa (IRPA). MIC50 and MIC90 were 32microgram/mL and 512microgram/mL, respectively. The susceptibility of IRPA against piperacillin/tazobactam was 59%. Of the 50 IRPA strains, only two were PCR positive for blaVIM and none for blaIMP.
Imipenem
;
Polymerase Chain Reaction
;
Pseudomonas aeruginosa*
;
Pseudomonas*
3.Abrupt Increase in Rate of Imipenem Resistance in Acinetobacter baumannii Complex Strains Isolated from General Hospitals in Korea and Correlation With Carbapenem Administration During 2002–2013.
Young Ah KIM ; Yoon Soo PARK ; Taemi YOUK ; Hyukmin LEE ; Kyungwon LEE
Annals of Laboratory Medicine 2018;38(2):179-181
No abstract available.
Acinetobacter baumannii*
;
Acinetobacter*
;
Hospitals, General*
;
Imipenem*
;
Korea*
4.Evaluation of Methods for Detection of Antimicrobial Resistance of Acinetobacter baumannii to Imipenem.
The Korean Journal of Laboratory Medicine 2003;23(6):388-394
BACKGROUND: In our hospital, an abrupt increase in the resistant rate of A. baumannii to imipenem was observed. We evaluated the imipenem minimal inhibitory concentration (MIC) of an automated system that our laboratory is using, by comparing with those of other methods. METHODS: During the period from February 2002 to February 2003, the imipenem MICs of the agar dilution method, Etest(R), and the disk diffusion method, were compared for imipenem-resistant A. baumannii tested by an automated system in 46 samples at Chung-Ang University Phil-Dong Hospital. We tested for susceptibility to imipenem with the Vitek system by using the GNI card, the disk diffusion method by using the imipenem disk (BBL(TM)), and the agar dilution method. PCR testing of the isolates for carbapenemase genes (IMP-1 and VIM-2) detected in other hospitals was done using published primers and conditions. RESULTS: By the agar dilution method, 23 (50.0%) isolates were susceptible to imipenem, 14 (30.4%) isolates were intermediate, and 9 (19.6%) isolates were resistant. However, by the Etest, 8 (17.4%) were susceptible to imipenem, and 28 (60.9%) isolates were resistant. By the disk diffusion method, the susceptible isolates were 14 (30.4%) and the resistant isolates were 17 (37.0%). Quantitative agreement between the agar dilution method and the disk diffusion test gave an inverse linear correlation coefficient (r=-0.564). The results of the 13 isolates, whose results of the MIC were below 2 or above 16 in the agar dilution method, corresponded with the Etest and the disk diffusion test. The IMP-1 gene was detected in one isolate. CONCLUSIONS: It is recommended that when a gram-negative bacilli isolate including A. baumannii is characterized as resistant to imipenem by the Vitek system, an additional simple test, such as the disk diffusion assay, might be used.
Acinetobacter baumannii*
;
Agar
;
Diffusion
;
Imipenem*
;
Polymerase Chain Reaction
5.In vitro Comparison of Anti-Biofilm Effects against Carbapenem-Resistant Acinetobacter baumannii: Imipenem, Colistin, Tigecycline, Rifampicin and Combinations.
Joon Young SONG ; Hee Jin CHEONG ; Ji Yun NOH ; Woo Joo KIM
Infection and Chemotherapy 2015;47(1):27-32
BACKGROUND: Multi-drug resistant (MDR) Acinetobacter baumannii has emerged as one of the most important nosocomial pathogens. In addition to the diverse resistance mechanisms, some A. baumannii strains are known to have biofilm-producing capacity, thereby decreasing antibiotic effectiveness. MATERIALS AND METHODS: This study was designed to assess biofilm-producing capacity of three different MDR A. baumannii strains with diverse resistance mechanisms (OXA-51, IMP-1 and VIM-2 type beta-lactamases), and intended to compare the effect of each antibiotic regimen (rifampicin, colistin, imipenem, tigecycline, rifampicin-imipenem and rifampicin-colistin) on mature A. baumannii biofilms using in vitro polystyrene plate biofilm assay. RESULTS: Among three MDR A. baumannii strains, only VIM-2 strain produced strong biofilm compared to the controls (optical density, 8.04 +/- 2.16 vs. 0.49 +/- 0.26). Regarding VIM-2 strains, none of imipenem, colistin and rifampicin reduced biofilm formation alone at MIC of each antibiotic agent (inhibition of biofilm synthesis, less than 30%). In comparison, tigecyclin (0.76 +/- 0.23), imipenem-rifampicin (1.07 +/- 0.31) and colistin-rifampicin (1.47 +/- 0.54) showed a significant inhibition of biofilm synthesis compared to the positive controls at 48 hours after incubation (P<0.01). Tigecycline inhibited biofilm formation even at the one fourth level of MIC (1.17 +/- 0.21). Likewise, both imipenem and colistin were also effective even with the reduced concentrations when those were combined with rifampicin. Such biofilm-inhibiting effects with those antibiotic regimens sustained up to 96 hours after incubation. CONCLUSION: Tigecycline, imipenem-rifampicin and colistin-rifampicin would be effective for the prevention or reduction of biofilm formation caused by A. baumannii strains.
Acinetobacter baumannii*
;
Anti-Bacterial Agents
;
Biofilms
;
Colistin*
;
Imipenem*
;
Polystyrenes
;
Rifampin*
6.In Vitro Activity of Antimicrobial Combination against Multidrug-resistant Strains of Acinetobacter baumannii.
The Korean Journal of Laboratory Medicine 2005;25(5):312-316
BACKGROUND: Acinetobacter baumannii has been reported as a major cause of nosocomial infections with increasing frequency. Recently, the emergence of carbapenem-resistant strains has become a major problem in treatment. The use of nontraditional agents such as colistin and a combination therapy have been tried. The purpose of this study was to evaluate the activity of antimicrobial combinations against multidrug-resistant (MDR) A. baumannii. METHODS: Twenty-nine strains of MDR A. baumannii, either resistant or intermediate to imipenem, were collected from February 2003 to February 2004. Minimum inhibitory concentrations (MICs) were determined by the agar dilution method. The checkerboard method was used to assess the activity of ampicillin-sulbactam in combination with amikacin, tobramycin or meropenem and colistin in combination with ceftazidime, meropenem, or rifampin. RESULTS: The MIC90 of ceftazidime and cefepime were 2, 048 g/mL and 512 g/mL, respectively, while the MIC90 of colistin was 0.5 g/mL. The antimicrobial combinations that showed an additive effect for one or two strains were colistin with rifampin or ceftazidime and ampicillin-sulbactam with tobramycin or meropenem. Other antimicrobial combinations showed indifferent effects against most strains. There were no synergistic or antagonistic combinations. CONCLUSIONS: These data suggested that colistin may be an alternative drug for MDR A. baumannii. For the effective treatment of patients infected with these resistant strains, further studies are needed to evaluate antimicrobial combinations against a large number of heterogeneous isolates, and these studies must be followed by clinical trials.
Acinetobacter baumannii*
;
Agar
;
Amikacin
;
Ceftazidime
;
Colistin
;
Cross Infection
;
Humans
;
Imipenem
;
Microbial Sensitivity Tests
;
Rifampin
;
Tobramycin
7.Screening and Identification of Metallo-beta-Lactamase Gene in Clinical Isolates of Imipenem-Resistant Pseudomonas Aeruginosa.
In Suk KIM ; Won Il OH ; Jae Hoon SONG ; Nam Yong LEE
The Korean Journal of Laboratory Medicine 2004;24(3):177-182
BACKGROUND: The therapeutic difficulty due to wide-spread emergence of multiply resistant strains is a major problem in Pseudomonas aeruginosa infection. Carbapenem-resistant P. aeruginosa strains are being isolated with increasing frequency. Clinical isolates of P. aeruginosa with transferable imipen-em resistance due to production of metallo-beta-lactamase (MBL) have been reported. This study was performed to determine the usefulness of the imipenem-EDTA disk test to detect MBL, to examine the prevalence of MBL in a tertiary care hospital in Korea. METHODS: One hundred sixteen P. aeruginosa isolates with reduced susceptibilities to imipenem were collected during the period of 2000-2003 in the Samsung Medical Center. Imipenem-resistant P. aeruginosa isolates were examined for MBL production by imipenem-EDTA disk tests. To detect of blaIMP-1 , blaVIM-1, and blaVIM-2 genes, polymerase chain reactions (PCR) were performed and the positive isolates were confirmed by sequencing. RESULTS: Among 116 clinical isolates of P. aeruginosa, 20 isolates (17.2%) were positive for the imipenem-EDTA disk tests. Nineteen isolates (16.4%) carried VIM-2. Accoroding to PCR results, the sensitivity, specificity, and test efficiency of the imipenem-EDTA disk tests were 89%, 97%, and 96%, respectively. CONCLUSIONS: The imipenem-EDTA disk test is sensitive and specific for detecting VIM producer. VIM-2 may be an important MBL in P. aeruginosa in tertiary care hospitals the Korea. The spread of MBL genes could compromise the future usefulness of carbapenem for the treatment of gram-neg-ative bacilli infections.
Imipenem
;
Korea
;
Mass Screening*
;
Polymerase Chain Reaction
;
Prevalence
;
Pseudomonas aeruginosa*
;
Sensitivity and Specificity
;
Tertiary Healthcare
8.Molecular Characteristics of blaOXA-23-Producing Acinetobacter baumannii Isolated from a University Hospital.
In Ho JANG ; Soon Deok PARK ; Young UH ; Gyu Sang LEE ; Jong Bae KIM ; Il CHOI
Annals of Clinical Microbiology 2013;16(3):126-133
BACKGROUND: Multi-drug resistant (MDR) Acinetobacter baumannii has emerged as a significant infectious agent in hospitals worldwide. The purpose of this study was to determine the molecular characterization of MDR A. baumannii clinical isolates. METHODS: Two hundred eighty-five strains of non-duplicated A. baumannii collected from March to November 2011 from a university hospital laboratory located in the Wonju area of the Gangwon province of Korea were analyzed for MDR genes. RESULTS: All of the 285 imipenem-resistant A. baumannii isolates were encoded by a blaOXA-23-like gene, and all isolates with the blaOXA-23-like gene had the upstream element ISAba1. The 16S rRNA methylase gene armA was detected in 153 (50.2%) clinical isolates, but rmtA, rmtB, rmtC, rmtD and npmA were not detected in any isolates in the present study. The gene encoding aac(6')-Ib was the most prevalent aminoglycoside-modifying enzyme. The sequencing data for the quinolone resistance-determining region of gyrA and parC revealed the presence of Ser (TCA) 83 to Leu (TTA) and Ser (TCG) 80 to Leu (TTG) substitutions. All but one of the 285 A. baumannii isolates showed similar band patterns on repetitive extragenic palindromic-PCR profiles. CONCLUSION: The molecular characteristics of the resistance genes of MDR A. baumannii isolates obtained from the Wonju area of Gangwon province were similar to those of other areas in Korea.
Acinetobacter
;
Acinetobacter baumannii
;
beta-Lactamases
;
Genes, MDR
;
Imipenem
;
Korea
;
Laboratories, Hospital
;
Methyltransferases
9.Treatment of Catheter-related Bacteremia with an Antibiotic Lock Protocol in Hemodilaysis Patients.
Hae Ri LEE ; Young Ki LEE ; Young Lim SONG ; Su Jin KIM ; Min Ha JOO ; Seong Gyun KIM ; Ji Eun OH ; Jang Won SEO ; Ja Ryong KOO ; Hyung Jik KIM ; Jung Woo NOH ; Sang June SHIN
Korean Journal of Nephrology 2005;24(6):903-911
BACKGROUND: Catheter-related bacteremia is a frequent complication among hemodialysis patients using a tunneled cuffed catheter. The standard therapy of catheter-related bacteremia involves both systemic antibiotics and catheter replacement. This study was performed to evaluate the effect of antibiotic lock therapy in conjugation with systemic antibiotics without catheter removal on catheter-related bacteremia. METHODS: Thirty six chronic hemodialysis patients with tunneled cuffed catheter were monitored for infection between July 2001 and July 2005. We analyzed the efficacy of antibiotic lock protocol compared with systemic antibiotics alone. RESULTS: Twenty-nine episodes of catheter-related bacteremia occurred in 27 patients during the study periods. The incidence of catheter-related bacteremia was 1.5 episodes/1000 catheter-days. A single gram-positive coccus grew in the 16 cases (55.2 %), and gram-negative organisms grew in the 69 cases (31.0%). Sixteen of 18 patients (88.9%) treated with antibiotic lock protocol had successful catheter salvage versus only 6 of the 11 patients (54.5%) treated with systemic antibiotics alone (p=0.05). Three patients with Burkholderia pickettii and a patient with Acinetobactor calcoaceticus-baumannii complex were treated with antibiotic lock protocol with systemic ciprofloxacin and imipenem, respectively. CONCLUSION: This study suggests that antibiotic lock protocol in eradicating catheter-related bacteremia is effective treatment without requiring catheter replacement.
Anti-Bacterial Agents
;
Bacteremia*
;
Burkholderia
;
Catheters
;
Ciprofloxacin
;
Humans
;
Imipenem
;
Incidence
;
Renal Dialysis
10.A STUDY ON THE ANTIMICROBIAL SUSCEPTIBILITY OF ORAL MICROFLORA IN CHILDREN SUSCEPTIBLE TO INFECTIVE ENDOCARDITIS.
Sung Hwan PARK ; Sang Hun SHIN ; In Kyo CHUNG
Journal of the Korean Association of Oral and Maxillofacial Surgeons 1999;25(2):122-132
The present study has been performed to evaluate 20 cardiopathy children and 20 healthy children's oral micorbes at the point of antimicrobial susceptibilities for antimicrobial prophylaxis to prevent bacterial endocarditis. The results were as follows: 1. Both groups had similar oral microbes. 2. The antimicrobial susceptibility of S. viridans were: Penicillin< Oxacillin< Ampicillin< Cephalothin< Erythromycin< Clindamycin< Gentamicin< Ciprofloxacin< Vancomycin=Imipenem. The cardiopathy group was slightly lower antimicrobial susceptibility rates than healthy group. 3. The antimicrobial susceptibility of Neisseriaceae were: Clindamycin< Erythromycin< Vancomycin< Penicillin< Gentamicin< Cephalothin< Ciprofloxacin< Imipenem. The antibiotics of bacterial endocarditis antibiotic prophylaxis regimens for dental procedures according to the American Heart Association were generally lower antimicrobial susceptibilities, so they were considered inadequate for the first selective antibiotics and Imipemem was best suitable antimicrobials. Conclusively, when choose antimicrobials for treatment or antimicrobial prophylaxsis for bacterial endocarditis, surveillant culture must be performed to evaluated personal antimicrobial susceptibilities of intraoral microbes for proper antimicrobial choice for dental procedures.
American Heart Association
;
Anti-Bacterial Agents
;
Antibiotic Prophylaxis
;
Child*
;
Endocarditis*
;
Endocarditis, Bacterial
;
Humans
;
Imipenem
;
Neisseriaceae