Rapid Identification of OXA-48-like, KPC, NDM, and VIM Carbapenemase-Producing Enterobacteriaceae From Culture: Evaluation of the RESIST-4 O.K.N.V. Multiplex Lateral Flow Assay

There is an urgent need for accurate and rapid diagnostic assays capable of identifying carbapenemase-producing Enterobacteriaceae (CPE). We assessed the performance of the RESIST-4 O.K.N.V. (OKNV) assay (Coris BioConcept, Gembloux, Belgium) for the identification of oxacillinase (OXA)-48-like-, Klebsiella pneumoniae carbapenemase (KPC)-, New Delhi metallo-β-lactamase (NDM)-, and Verona integron-encoded metallo-β-lactamase (VIM)-producing Enterobacteriaceae grown on sheep blood agar (SBA) and the CHROMagar KPC medium. Sixty-five carbapenem-resistant Enterobacteriaceae (CRE) isolates with characterized carbapenemase content were used to evaluate the OKNV assay. The assay correctly identified all 30 isolates that produced one of the four targeted carbapenemase families. Additionally, it correctly identified 15 isolates that co-produced KPC and NDM, VIM and NDM or OXA-48-like and NDM, but failed to identify an NDM-1 and OXA-232 co-producing Klebsiella pneumoniae isolate. All 16 non-carbapenemase-producing CRE and four CPE isolates exhibited negative results, and no cross-reaction was observed. Overall, the sensitivity and specificity of the assay were 97.8% and 100%, respectively. The OKNV assay is an accurate and rapid assay for identifying OXA-48-like, KPC, NDM, and VIM carbapenemases produced by Enterobacteriaceae isolates cultured on both SBA and the CHROMagar KPC media in the clinical microbiology laboratory.

Role and mechanism of circular RNA-vimentin in the proliferation and apoptosis of colorectal cancer cells / 中华消化杂志

Objective To investigate the role and mechanism of circular RNA-vimentin (circ-VIM) in the proliferation and apoptosis of colorectal cancer cells.Methods From December 2016 to December 2017, at Department of General Surgery of The First Affiliated Hospital of Zhengzhou University, the clinical data of 100 patients who underwent radical resection of colorectal cancer and were confirmed by pathological examination after operation were collected.The tumor tissues and corresponding paracancerous tissues (negative control) were also collected.The expression of circ-VIM in the colorectal cancer tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR).The proliferation of HCT-116 and HT29 colorectal cancer cells was detected by cell counting kit-8 assay.The ratio of apoptosis of HCT-116 and HT29 cells was measured by annexin Ⅴ/propidium iodide double staining assay.The mitochondrial membrane potential of HCT-116 and HT29 cells was examined by 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide (JC-1) assay.The expression changes of protein kinase B and mammalian target of rapamycin were tested by Western blotting.The target miRNA of circ-VIM was predicted by miRDB software.T-test and chi-square test were performed for statistical analysis. Results The expression of circ-VIM in colorectal cancer tissues was 2.387 ±0.536, which was higher than that in corresponding paracancerous tissues (1.110 ±0.134), and the difference was statistically significant (t =23.096, P <0.01).And the expression levels of circ-VIM were significantly different in patients with different tumor size, TNM stage and lymph node metastasis (all P <0.05).The proliferation of HCT-116 cells and HT29 cells in lenti-circ-VIM group was 0.737 ±0.023 and 0.835 ±0.025, respectively, which were both higher than those in control group (0.449 ±0.020 and 0.531 ±0.019), and the differences were statistically significant (t =20.706 and-15.374, both P <0.01).The proliferation of HCT-116 cells and HT29 cells in lenti-circ-VIM-shRNA group was 0.236 ±0.027 and 0.243 ±0.019, which were lower than those in control group, and the differences were statistically significant (t =24.557 and -23.197, both P <0.01).The ratio of apoptosis of HCT-116 cells and HT29 cells in lenti-circ-VIM-shRNA group was (18.00 ±1.82)％ and (20.80 ±0.61)％, which was higher than those in control group ((6.64 ±2.01)％ and (7.35 ±1.36)％), and the differences were statistically significant (t =8.826 and 17.454, both P <0.01).The fluorescence intensity ratio of JC-1 aggregate and JC-1 monomer of HCT-116 cells and HT29 cells in lenti-circ-VIM-shRNA group was 2.21 ±0.12 and 1.40 ±0.11, which was lower than those in control group (14.54 ±1.00 and 9.24 ±1.18), and the differences were statistically significant (t =-19.558 and-15.685, both P <0.01), which indicated mitochondrial membrane potential decreased.After treated with lenti-circ-VIM-shRNA, the expression of phosphorylated protein kinase B, phosphorylated mammalian target of rapamycin, B-cell lymphoma-2 and mitochondrial cytochrome C at protein level were all down-regulated, however the expression of cytoplasmic cytochrome C, B-cell lymphoma-2 associated X protein and cleaved caspase-3 at protein level were all up-regulated.When the expression of circ-VIM was up-regulated, the expression of miRNA-147b, miRNA-4447 and miRNA-3656 was down-regulated.When the expression of circ-VIM was down-regulated, the expression of miRNA-147b, miRNA-4447 and miRNA-3656 was up-regulated.Conclusion The expression of circ-VIM in colorectal cancer is abnormally increased, which is involved in the proliferation and apoptosis of colorectal cancer cells.

Study on Carbapenemase Genotype of Imipenem-resistant Gram-negative Bacilli in Intensive Care Unit of 3 Third Grade Class A Hospitals from Qingdao Area / 中国药房

OBJECTIVE: To analyze carbapenemases genotype of imipenem-resistant Gram-negative bacilli in intensive care unit (ICU) of 3 third grade class A hospitals from Qingdao area, so as to provide reference for drug-resistant bacteria infection prevention and treatment in clinic. METHODS: From Jan. 2013 to Jun. 2016, each 60 strains of imipenem-resistant Klebsiella pneumoniae (IRKP), imipenem-resistant Pseudomonas aeruginosa (IRPA) and imipenem-resistant Acinetobacter baumanii (IRAB) were collected from 3 third grade class A hospitals from Qingdao area. Drug sensitivity test was performed by using Kirby-Bauer method. Phenotypes of carbapenemases were determined by Carba NP trial. PCR was applied to amplify carbapenemase gene; Sanger seqnencing method was adopted for bi-directional sequencing; Blast comparison with GenBank database was conducted. RESULTS: Three kinds of imipenem-resistant Gram-negative bacilli showed high drug resistance to majority commonly used antibiotics as piperacillin, cefazolin, imipenem and cilastatin sodium, gentamicin, etc., but were sensitive to polymyxin B (resistance rate of 0). Among 180 drug-resistant strains, there were 52 strains of class A carbapenems, 13 strains of class B carbapenems and 39 strains of class D carbapenems; the detection rates of them were 28. 89％, 7. 22％ and 21. 67％, respectively. There were 52 strains of KPC-2 gene (IRKP), 4 strains of IMP-1 gene (IRPA), 8 strains of VIM-2 gene (7 strains of IRPA, 1 strain of IRAB), 39 strains of OXA-23 gene (IRAB); the detection rates of them were 28. 89％, 2. 22％, 4. 44％, 21. 67％; all strains were not detected 1MP-2, VIM-1, NDM-1, OXA-24, OXA-58 genes. Results of Blast comparison showed that above detected genes were absolutely homology with the corresponding genes in GenBank database. CONCLUSIONS: Drug resistance of imipenem-resistant Gram-negative bacilli in ICU of 3 third grade class A hospitals is serious in this region, which are nearly no-sensitive to most of commonly used antibiotics in clinic. Main genotypes included KPC-2 (K. pneumoniae), OXA-23 (A. baumanii) and IMP-1 and VIM-2 (P. aeruginosa).

Molecular identification of multidrug resistant Enterobacter hormaechei in Venezuela / Identificación molecular de Enterobacter hormaechei multidrogoresistente en Venezuela

Besides the importance of Enterobacter cloacae species complex as a nosocomial pathogen, little is known about the frequency of each species/genotype. Here, we describe a strain of E. hormaechei subsp. hormaechei isolated from a bronchial secretion of a patient, in the Intensive Care Unit at the General Hospital of Cumaná, Venezuela, who died due to complications of his infection. The molecular identification was done by sequencing the 16S rRNA gene and comparing it to sequences from the GenBank. This strain showed resistance to multiple families of antibiotics (MDR), and the genes blaKPC and blaVIM were detected by PCR. This is the first time E. hormaechei has been identified in Venezuela.

A pesar de la importancia de las especies del complejo Enterobacter cloacae como patógeno nosocomial, poco se conoce sobre la frecuencia de cada especie/genotipo. Aquí se describe una cepa de E. hormaechei subsp. hormaechei aislada de una secreción bronquial de un paciente internado en la Unidad de Cuidados Intensivos del Hospital General de Cumaná, Venezuela, quien murió producto de complicaciones de su infección. La identificación molecular fue hecha por secuenciación del gen ARNr 16S y porcomparación con las secuencias del GenBank. Esta cepa mostró resistencia a múltiples familias de antibióticos (MDR) y se detectaron los genes blaKPCyblaVIMpor PCR. Este es el primer reporte de E. hormaechei en Venezuela.

Effect of VIM in EV71 infection in human microvascular endothelial cells / 实用医学杂志

Objectives To study the effect of VIM in Enterovirus 71 (EV71) infection of (human brain microvascular endothelial cells (HBMEC) and elaborating the mechanism of EV71 infection in the nervous system. Methods Knocked out the VIM by CRISPR technology , the differences in EV71 absorption , replication , release between wild VIM and VIM knocked-out (VIM-KO) HBMEC were detected by fluorescence quantitative PCR. Results 4 ℃ absorption experiment conformed that EV71 adsorption in VIM- KO is 40% less than in the normal HBMEC. After EV71 infect HBMEC for 48 h (48 h p. i.), the quantitative PCR result showed intracellular viral RNA in VIM-KO was only 1/12 of that in the normal HBMEC. Also the extracellular viral RNA was quantified, and the number of cells in VIM-KO had been reduced 1.4 times compared with the normal HBMEC. Conclusions Once VIM knocking out, EV71 attachment has been obviously reduced. Meanwhile, the level of viral RNA replication and release are decreased compared with the normal HBMEC. VIM may be an attachment receptor of EV71 in HBMEC , when the virus invades HBMEC with the binding of VIM. Moreover , VIM plays an important role in the replication and release of EV71.

KPC and VIM producing Enterobacter cloacae strain from a Hospital in Northeastern Venezuela / Enterobacter cloacae productor de KPC y VIM en un Hospital del Noreste de Venezuela

An 83-year-old male patient is admitted to the central hospital in Cumaná, Venezuela with severe urinary infection, history of hospitalizations and prolonged antimicrobial treatments. A strain of Enterobacter cloacae was isolated showing resistance to multiple types of antibiotics (only sensitive to gentamicin), with phenotype of serine- and metallo-carbapenemases. Both, blaVIM-2 and blaKPC genes were detected in the isolate. This is the first report of an Enterobacteriaceae species producing both KPC carbapenemase and VIM metallo carbapenemase in Venezuela. This finding has a great clinical and epidemiological impact in the region, because of the feasibility of transferring these genes, through mobile elements to other strains of Enterobacter and to other infection-causing species of bacteria.

En un paciente masculino de 83 años, que ingresó al Hospital de Cumaná, Venezuela, con diagnóstico de infección urinaria severa, antecedentes de hospitalización y diferentes tratamientos antimicrobianos durante largos periodos de tiempo, se aisló una cepa de Enterobacter cloacae, la cual evidenció resistencia a múltiples tipos de antibióticos (solo sensible a gentamicina) y con fenotipo de carbapenemasas de tipo serina y metalobetalactamasa. Los genes blaVIM-2 y blaKPC fueron detectados en esta cepa. Este representa el primer reporte de una especie de Enterobacteriaceae productora simultánea de carbapenemasa KPC y metalobetalactamasa VIM en Venezuela. Esto tiene un gran impacto clínico y epidemiológico en la región por la posibilidad de transferencia de estos genes a otras cepas de Enterobacter u otras especies bacterianas causantes de infecciones, por medio de elementos móviles.

Detection and homology analysis on metallo-β-lactamases gene in clinically isolated gram-negative bacteria / 中国感染控制杂志

Objective To investigate the detection of IMP andVIM metallo-β-lactamases (MβLs)genes in clinically iso-lated gram-negative bacteria as well as bacterial resistance toβ-lactam antimicrobial agents.Methods 113 clinically isolated bacteria were performed antimicrobial susceptibility testing by Kirby-Bauer method ,drug-resistant genes IMP and VIM were detected by polymerase chain reaction (PCR),PCR products were sequenced and aligned with BLAST software. Results VIM gene was detected in 1 Pseudomonas fluorescens strain ,IMP gene was detected in 15 strains ,they were Klebsiella pneumoniae (n=6),Acinetobacter baumannii (n=3),Escherichia coli (n=2),Ralstonia picket-tii (n=1),Pseudomonas aeruginosa (n=1 ),Citrobacter amalonaticua (n=1 ),and Enterobacter cloacae (n=1 ). BLAST results showed that VIM gene was VIM-2 subtype,similarity with gene bank was 99%;all IMP genes were IMP-1 subtype,which were highly homologous ,similarity was 98%-99%.Resistant rates of IMP positive strains to ceftriaxone,cefotaxime,cefoxitin,aztreonam and imipenem were all significantly higher than negative strains (all P <0.05).Conclusion IMP genes of different strains are highly homologous,all are IMP-1 type,indi-cating that IMP genes are highly transmissible and can spread among different species of bacteria.IMP genes are related with resistance ofβ-lactam antimicrobial agents.

Characteristics of Metallo-beta-Lactamase-Producing Pseudomonas aeruginosa in Korea

BACKGROUND: The aim of this study was to investigate the molecular epidemiological characteristics of metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa clinical isolates in Korea. MATERIALS AND METHODS: Three hundred and twenty nine P. aeruginosa clinical isolates were collected from 23 general hospitals in Korea from March to June 2014. Species were identified by matrix-assited laser desorption/ionization-time of flight and 16S rRNA sequencing. Antimicrobial susceptibility was determined by disk diffusion methods. Further, minimum inhibitory concentrations of carbapenems were determined by Etest. Polymerase chain reaction and sequencing were performed to identify genes encoding MBLs. Multi-locus sequence typing and pulsed-field gel electrophoresis were performed to determine epidemiological characteristics of MBL-producing P. aeruginosa isolates. RESULTS: Of the 329 isolates, 229 (69.6%) were susceptible to the carbapenems tested, including imipenem and meropenem; while 100 (30.4%) were non-susceptible to more than one of the carbapenems. Genes encoding imipenemase-6 (IMP-6) and Verona imipenemase-2 (VIM-2) MBLs were identified in 21 (6.4%) isolates (n = 17 and 4, respectively). All MBL-producing isolates showed multi-drug resistant phenotype, and a majority (n = 19) of the isolates were identified as sequence type 235 (ST235). The remaining isolates (n = 2) were identified as ST309 and ST463. CONCLUSION: P. aeruginosa ST235 might play an important role in dissemination of MBL genes in Korea.

FIRST REPORT OF METALLO-β-LACTAMASES PRODUCING Enterobacter spp. STRAINS FROM VENEZUELA / Primer reporte de cepas de Enterobacter spp productoras de metalobetalactamasas de Venezuela

Clinical strains of Enterobacter were isolated from Cumana's Central Hospital in Venezuela, and classified as E. cloacae (21), E. aerogenes (7), E. intermedium (1), E. sakazakii (1) and three unclassified. The strains showed high levels of resistance, especially to SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). This is the first report for South America of blaVIM-2 in two E. cloacae and one Enterobacter sp., which also showed multiple mechanisms of resistance. Both E. cloacae showed blaTEM-1, but only one showed blaCTX-M-15 gene, while no blaSHV was detected.

Cepas clínicas de Enterobacter fueron aisladas del Hospital central de Cumaná en Venezuela, y se clasificaron como E. cloacae (21), E. aerogenes (7), E. intermedium (1), E. sakazakii (1) y 3 sin clasificar. Las cepas mostraron altos niveles de resistencia, especialmente a SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). Este es el primer reporte de América del Sur de blaVIM-2 en dos cepas de E. cloacae y una de Enterobacter sp., las cuales también mostraron múltiples mecanismos de resistencia. Ambas especies de E. cloacae mostraron genes blaTEM-1, pero solo una mostro el gen blaCTX-M-15, mientras que blaSHV no fue detectado.

Detección del gen codificante de la metalo-ß-lactamasa VIM-2 en un integrón de clase 1 asociado con el gen blaCTX-M-2 en un aislamiento clínico de Pseudomonas aeruginosa en el Uruguay: primera comunicación

Con el fin de analizar la presencia de metalo-ß-lactamasas en nuestro medio, se incluyeron en este estudio aislamientos de Pseudomonas aeruginosa causantes de infecciones nosocomiales en un centro hospitalario del Uruguay, en el período comprendido entre abril y setiembre de 2008. En un aislamiento se detectó la presencia del gen codificante de la metalo-ß-lactamasa VIM-2 asociado a un integrón de clase 1 y del gen codificante de una ß-lactamasa de espectro extendido CTX-M-2. Esta es la primera comunicación de la presencia de los genes blaCTX-M-2 y blaVIM-2 en un mismo aislamiento de P. aeruginosa. A pesar de que las carbapenemasas ya han sido ampliamente documentadas en varias partes del mundo, esta es la primera comunicación de una metalo-ß-lactamasa adquirida con actividad carbapenemasa en bacterias patógenas encontradas en el Uruguay.

VIM-2 metallo-ß-lactamase gen detection in a class 1 integron associated to blaCTX-M-2 in a Pseudomonas aeruginosa clinical isolate in Uruguay: first communication. In order to analyze the presence of metallo-ß-lactamase in our country, we included in this study Pseudomonas aeruginosa isolates causing nosocomial infections in a hospital from Uruguay. The presence of a metallo-ß-lactamase VIM-2 in a class 1 integron and of an extended spectrum -lactamase CTX-M-2 was detected in one isolate. This is the first report of both genes, blaCTX-M-2 and blaVIM-2,in the same P. aeruginosa isolate. Although carbapenemases have been extensively documented in the world, this is the first report of an acquired metallo-ß-lactamase with carbapenemase activity in pathogenic bacteria in Uruguay.

Study on the antibiotic resistance, homology of imipenem-resistant Pseudomonas aeruginosa strains isolated from older / 中华微生物学和免疫学杂志

Objective To identify the antibiotic resistance, homology of imipenem-resistant Pseudomonas aeruginosa strains isolated from older in Zhejiang Hospital and the carbapenemases determinants of imipenem-resistant strains. MethodsTwo hundred and sixty-two strains of Pseudomonas aeruginosa were isolated through May 2006 to May 2009 from older in Zhejiang Hospitals. K-B method was used to determine the 16 antimicrobial agents resistance of these 262 strains. The MICs of strains to 14 antimicrobial agents were determined by agar dilution and E test method. The coding sequence of Metallo-β-lactamases (MBL) were amplified, PCR products were purified, cloned and sequenced. The homology of these isolates was analyzed by pulse-field gel electrophoresis(PFGE). ResultsOne hundred and four strains of imipenem-resistant Pseudomonas aeruginosa were screened from 262 strains. The resistant rates of 104 isolates of Pseudomonas aeruginosa to ampicillin/sulbactam and cefoperazone/sulbactam were 78.9％ and 35.9％ ; polymyxin E had a minimal resistance of 6.0％ ; minocycline had a resistance rate of 58.3％. The resistant rates to other antimicrobial agents were more than 70.0％. Twelve imipenem-resistant Pseudomonas aeruginosa strains contained MBL gene and two kinds of integron were detected from 10 of these 12 strains. Twelve strains of Pseudomonas aeruginosa belonged to 5 epidemic PFGE-clone. ConclusionAll of the imipenem-resistant Pseudomonas aeruginosa which had cause outbreaks in Zhejiang Hospital. MBL were not the most popular gene type. All of the MBL gene types were VIM-2. The blaVIM-2 gene cassettes located in diflerent class 1 integrons. The integrons dissemination was the most important style of strains spread.

Prevalence of Metallo-beta-lactamases in Imipenem-non-susceptible Pseudomonas aeruginosa and Acinetobacter baumannii / 대한임상미생물학회지

BACKGROUND: Metallo-beta-lactamases (MBLs) have been reported in gram negative bacilli and are becoming increasingly important clinically because the enzymes hydrolyse almost all beta-lactams, including carbapenems. Thus, the present study was conducted to determine the prevalence of MBL types in imipenem-nonsusceptible Pseudomonas aeruginosa and Acinetobacter baumannii isolated from a tertiary teaching hospital. METHODS: Imipenem-nonsusceptible strains, 128 P. aeruginosa and 93 A. baumannii, were collected from clinical specimens. Identification and susceptibility tests were determined by Vitek GNI and GNS cards. MBL production was determined by modified Hodge test and imipenem-EDTA synergy test. Multiplex PCR amplification of MBL genes including blaIMP-1, blaVIM-1 and blaVIM-2 were performed. RESULTS: Thirty-one P. aeruginosa (24.2%) isolates and 3 A. baumannii (3.2%) were found to be MBL producers. In P. aeruginosa, 20 (15.6%) and 11 (8.6%) isolates were positive for blaIMP-1 and blaVIM-2, respectively whereas 1 (1.0%) and 2 (2.2%) isolates in A. baumannii, respectively. CONCLUSION: IMP-1 is more prevalent MBL type than VIM-2 among imipenem-nonsusceptible P. aeruginosa unlike in other studies. Larger numbers of isolates and sequential studies are strongly recommended for the useful evaluation and monitoring of MBL production in the hospital setting to infection-control.

Metallo-beta-Lactamase-Producing Pseudomonas spp. in Korea: High Prevalence of Isolates with VIM-2 Type and Emergence of Isolates with IMP-1 Type

PURPOSE: Two Korean nationwide studies showed that metallo-beta-lactamases (MBLs)-producing-Pseudomonas spp. are not rare. The aim of this study was to assess the trends of MBL-producing isolates among imipenem-resistant isolates of Pseudomonas spp. MATERIALS AND METHODS: Imipenem-resistant clinical isolates were collected from 23 hospitals and one commercial laboratory participating in the KONSAR program in 2005. Polymerase chain reaction (PCR) was used to detect MBL genes. RESULTS: Alleles of MBL genes were detected in 10.8% of 415 Pseudomonas aeruginosa and 66.7% of 12 P. putida isolates from 18 of 24 hospitals/laboratory. Among the 14 IMP-1-like and 39 VIM-2-like MBLs, emergence of IMP-6 was detected for the first time. CONCLUSION: Prevalence of MBL-producing P. aeruginosa has not significantly increased, but IMP-6 emerged in P. aeruginosa.

Antimicrobial Resistance among Clinical Isolates of Pseudomonas aeruginosa from Non-tertiary Care Hospitals in Korea, 2002-2004

BACKGROUND: Increasing numbers of resistant and multidrug resistant (MDR) isolates of Pseudomonas aeruginosa have become a worldwide problem. This report provides the trend of antimicrobial resistance, the proportions of MDR and metallo-beta-lactamase-producing isolates among clinical isolates of P. aeruginosa in Korea. MATERIALS AND METHODS: Clinical isolates of P. aeruginosa were collected from two representative reference laboratories during 2002-2004. Clinical information regarding specimens and type of hospital for isolates was investigated. Antimicrobial susceptibility against 11 antibiotics was tested by disk diffusion according to NCCLS criteria. MDR was assessed as resistance to > or =3 of the core drugs (ceftazidime, ciprofloxacin, gentamicin, imipenem and piperacillin). PCR assays and sequencing for detection of blaVIM-2 and blaIMP-1 gene were carried out. RESULTS: Of 1,748 P. aeruginosa isolates, 179 isolates were collected from primary care hospitals and 1,569 isolates were recovered from outpatients and inpatients in secondary care hospitals. From 2002 to 2004, rates of resistance to ceftazidime and imipenem increased from 10% to 12.3% and from 14.8% to 15.9%, respectively. Rates of resistance to amikacin (from 26.2% to 31.0%) and ciprofloxacin (from 35.6% to 46.2%) increased annually. In the period 2002-2004, decreasing of susceptibility to meropenem (from 83.4% to 76.8%) was observed, but meropenem was the most potent agent against P. aeruginosa isolates studied. During the 3-year period, MDR P. aeruginosa accounted for 26.4-33.5% of clinical isolates and the most common MDR phenotype was concurrent resistance to piperacillin, gentamicin and ciprofloxacin. The prevalence of VIM-2-producing isolates obviously increased from 1.7% in 2002 to 6.3% in 2004. CONCLUSIONS: These results suggested that MDR P. aeruginosa was already prevalent in one third of clinical isolates and VIM-2-producing P. aeruginosa isolates disseminated in non-tertiary care hospitals in Korea.

Antimicrobial Resistance among Clinical Isolates of Pseudomonas aeruginosa from Non-tertiary Care Hospitals in Korea, 2002-2004

BACKGROUND: Increasing numbers of resistant and multidrug resistant (MDR) isolates of Pseudomonas aeruginosa have become a worldwide problem. This report provides the trend of antimicrobial resistance, the proportions of MDR and metallo-beta-lactamase-producing isolates among clinical isolates of P. aeruginosa in Korea. MATERIALS AND METHODS: Clinical isolates of P. aeruginosa were collected from two representative reference laboratories during 2002-2004. Clinical information regarding specimens and type of hospital for isolates was investigated. Antimicrobial susceptibility against 11 antibiotics was tested by disk diffusion according to NCCLS criteria. MDR was assessed as resistance to > or =3 of the core drugs (ceftazidime, ciprofloxacin, gentamicin, imipenem and piperacillin). PCR assays and sequencing for detection of blaVIM-2 and blaIMP-1 gene were carried out. RESULTS: Of 1,748 P. aeruginosa isolates, 179 isolates were collected from primary care hospitals and 1,569 isolates were recovered from outpatients and inpatients in secondary care hospitals. From 2002 to 2004, rates of resistance to ceftazidime and imipenem increased from 10% to 12.3% and from 14.8% to 15.9%, respectively. Rates of resistance to amikacin (from 26.2% to 31.0%) and ciprofloxacin (from 35.6% to 46.2%) increased annually. In the period 2002-2004, decreasing of susceptibility to meropenem (from 83.4% to 76.8%) was observed, but meropenem was the most potent agent against P. aeruginosa isolates studied. During the 3-year period, MDR P. aeruginosa accounted for 26.4-33.5% of clinical isolates and the most common MDR phenotype was concurrent resistance to piperacillin, gentamicin and ciprofloxacin. The prevalence of VIM-2-producing isolates obviously increased from 1.7% in 2002 to 6.3% in 2004. CONCLUSIONS: These results suggested that MDR P. aeruginosa was already prevalent in one third of clinical isolates and VIM-2-producing P. aeruginosa isolates disseminated in non-tertiary care hospitals in Korea.

VIM-2 Type Metallo-beta-lactamase Producing Achromobacter xylosoxidans subsp. xylosoxidans Isolated from Urine Specimens

BACKGROUND: The dissemination of metallo-beta-lactamase (MBL) producing gram-negative bacilli is of great concern because MBL can hydrolyze carbapenem. We report herein the infection by VIM-2 type MBL producing Achromobacter xylosoxidans subsp. xylosoxidans. MATERIALS AND METHODS: For seven A. xylosoxidans subsp. xylosoxidans with reduced imipenem susceptibility, the detection for MBL was performed using EDTA double disk synergy test (EDTA- DDS) and the PCR for IMP-1, VIM-1 and VIM-2 genes. The minimal inhibitory concentration (MIC) of MBL producers were determined by microbroth dilution methods. The DNA fingerprinting analysis was performed by random amplified polymorphic DNA. RESULTS: All seven isolates were MBL producers when tested with EDTA-DDS test and these isolates were VIM-2 type confirmed by the PCR and DNA sequencing analysis. The MIC against imipenem ranged from 16 to 32 microgram/mL in these isolates. The DNA fingerprints of these isolates were identical. CONCLUSION: A. xylosoxidans subsp. xylosoxidans manifest resistance against imipenem by acquisition of VIM-2 type MBL. To our knowledge, this is the first report on the VIM-2 type MBL producing A. xylosoxidans subsp. xylosoxidans.

VIM-2 Type Metallo-beta-lactamase Producing Achromobacter xylosoxidans subsp. xylosoxidans Isolated from Urine Specimens

BACKGROUND: The dissemination of metallo-beta-lactamase (MBL) producing gram-negative bacilli is of great concern because MBL can hydrolyze carbapenem. We report herein the infection by VIM-2 type MBL producing Achromobacter xylosoxidans subsp. xylosoxidans. MATERIALS AND METHODS: For seven A. xylosoxidans subsp. xylosoxidans with reduced imipenem susceptibility, the detection for MBL was performed using EDTA double disk synergy test (EDTA- DDS) and the PCR for IMP-1, VIM-1 and VIM-2 genes. The minimal inhibitory concentration (MIC) of MBL producers were determined by microbroth dilution methods. The DNA fingerprinting analysis was performed by random amplified polymorphic DNA. RESULTS: All seven isolates were MBL producers when tested with EDTA-DDS test and these isolates were VIM-2 type confirmed by the PCR and DNA sequencing analysis. The MIC against imipenem ranged from 16 to 32 microgram/mL in these isolates. The DNA fingerprints of these isolates were identical. CONCLUSION: A. xylosoxidans subsp. xylosoxidans manifest resistance against imipenem by acquisition of VIM-2 type MBL. To our knowledge, this is the first report on the VIM-2 type MBL producing A. xylosoxidans subsp. xylosoxidans.

Production of VIM-2 Type Metallo-beta-Lactamase in Urinary Isolates of Providencia rettgeri / 대한진단검사의학회지

BACKGROUND: VIM-2 type metallo-beta-lactamase (MBL) producing strains are presently spreading to Pseudomonas spp., Acinetobacter spp. and even to Enterobacteriaceae such as Serratia marcescens, Enterobacter cloacae and Klebsiella pneumoniae in Korea. Recently we determined the phenotype and the genotype of three MBL-producing Providencia rettgeri isolated from urinary specimen of three patients with neurosurgical ward, and analyzed the blaVIM-2 containing integron of a P. rettgeri CBU852. METHODS: EDTA-disk synergy test was used for the screening of MBL, and the PCR for blaIMP-1, blaVIM-1 and blaVIM-2 was performed. The minimal inhibitory concentration of those isolates was determined by broth microdilution method, and the genomic DNA fingerprinting analysis was performed by random amplified polymorphic DNA (RAPD). The sequence of the blaVIM-2 containing integron was determined. RESULTS: Three P. rettgeri with reduced imipenem susceptibility showed the positive EDTA-disk synergy test and blaVIM-2 was detected by PCR. Antimicrobial susceptibility test showed the resistance to all beta-lactams tested, ciprofloxacin and aminoglycoside such as gentamicin, tobramycin and amikacin, indicating multidrug resistance of those isolates. RAPD analysis showed the identical DNA fingerprint of those three isolates. The novel class 1 integron, including aacA4, blaVIM-2, orf "ii" and orf "iii", was detected in a P. rettgeri CBU852. CONCLUSIONS: In this study, the multidrug resistant P. rettgeri CBU852 had blaVIM-2 containing novel class 1 integron. The emergence of blaVIM-2 producing P. rettgeri could compromise the use of carbapenem in treatment of infections caused by MBL producing bacteria. To our knowledge, this is the first report that VIM-2 MBL gene has been detected in P. rettgeri.

Comparison of Thalamotomy with Deep Brain Stimulation in Essential Tremor

OBJECTIVE: Thalamic lesioning and deep brain stimulation(DBS) have proved to be beneficial to the treatment of essential tremor(ET). The authors compared the effects and complications of two modalities. METHODS: A total of 34 patients with ET were treated with ventral intermediate(Vim) nucleus thalamotomy or Vim DBS from May 1999 to May 2003. The procedure of lesioning or stimulation were performed as usual manner with or without microelectrode recording. Postoperatively, utilizing the various combinations of frequency, voltage and pulse width optimized the stimulation. The degree of improvements of tremor and the occurrence of the complications were evaluated postoperatively and at follow-up. RESULTS: There were 38 procedures, including 27 with Vim thalamotomy and 11 with DBS, in 34 patients. Of the thalamotomy group, left Vim lesioning is 25 and right one is 2. Follow-up duration ranged from 12 to 57 months. In the thalamotomy group, the rate of overall good outcome was 88.9% but 12 patients (44.4%) showed permanent adverse effects. In the cases of stimulation, the rate of overall good outcome was 90.9% and two patients had acceptable dysarthria. CONCLUSION: Both Vim thalamotomy and Vim DBS were effective for the treatment of ET, although perioperative adverse effects tended to be higher in patients who had thalamotomy. In cases of DBS, adjustments of stimulation parameters enabled an acceptable position to be achieved with tremor control and unwanted effects.

Screening and Identification of Metallo-beta-Lactamase Gene in Clinical Isolates of Imipenem-Resistant Pseudomonas Aeruginosa / 대한진단검사의학회지

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.