BACKGROUND: Multidrug-resistant (MDR) Acinetobacter spp. acquire antimicrobial agent-resistance genes via class 1 integrons. In this study, integrons were characterized to investigate the antimicrobial resistance mechanisms of MDR Acinetobacter isolates. In addition, the relationship between the integron type and integron-harboring bacterial species was analyzed by using epidemiological typing methods. METHODS: Fifty-six MDR Acinetobacter spp.-A. baumannii (N=30), A. bereziniae (N=4), A. nosocomialis (N=5), and A. pittii (N=17)-were isolated. The minimum inhibitory concentrations (MICs) were determined on the basis of the results of the Epsilometer test (Etest). PCR and DNA sequencing was performed to characterize the gene cassette arrays of class 1 integrons. Multilocus sequence typing (MLST) and repetitive extragenic palindromic sequence (REP)-PCR were performed for epidemiological typing. RESULTS: Class 1 integrons were detected in 50 (89.3%) of the 56 isolates, but no class 2 or 3 integron was found within the cohorts. The class 1 integrons were classified into 4 types: 2.3-kb type A (aacA4-catB8-aadA1), 3.0-kb type B (aacA4-blaI(MP-1)-bla(OXA-2)), 3.0-kb type C (bla(VIM-2)-aacA7-aadA1), and 1.8-kb type D (aac3-1-bla(OXA-2)-orfD). Type A was most prevalent and was detected only in A. baumannii isolates, except for one A. bereziniae isolate; however, type B was amplified in all Acinetobacter isolates except for A. baumannii isolates, regardless of clone and separation time of the bacteria. CONCLUSIONS: Although class 1 integron can be transferred horizontally between unrelated isolates belonging to different species, certain types of class 1 integrons tend to transfer horizontally and vertically among A. baumannii or non-baumannii Acinetobacter isolates.
Acinetobacter/drug effects/isolation & purification/*metabolism ; Acinetobacter Infections/epidemiology/microbiology ; Acinetobacter baumannii/drug effects/isolation & purification/metabolism ; Anti-Bacterial Agents/pharmacology ; DNA, Bacterial/chemistry/metabolism ; Drug Resistance, Multiple, Bacterial ; Humans ; Integrons/*genetics ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Polymerase Chain Reaction ; Republic of Korea

In the initial published version of this article, there was a mistake in the title. The correct title should be “Impact of Day 14 Peripheral Blood Chimerism after Allogeneic Hematopoietic Stem Cell Transplantation on the Treatment Outcome of Non-Malignant Disease”.

BACKGROUND: Automated systems are used widely for pre-transfusion tests in blood banks, in an attempt to reduce effort and human error. We evaluated the clinical performance of an automated blood bank system, ORTHO VISION (Ortho-Clinical Diagnostics, Switzerland), for blood cross-matching. METHODS: Saline cross-matching was performed for 93 tests using 56 samples. Coombs cross-matching was performed for 400 tests using 166 samples. Saline cross-matching was compared for the automated ORTHO VISION and manual tube methods. Coombs cross-matching was compared for the automated ORTHO VISION and manual column agglutination technique (CAT) methods. The evaluation of 32 antibody-positive samples using the automated ORTHO VISION and manual CAT methods was compared by performing 97 cross-matching tests. Additionally, the ORTHO VISION efficiency and carryover were evaluated. RESULTS: The concordance rate of the saline cross-matching results between the manual method and automated ORTHO VISION was 100%. The concordance rate of coombs cross-matching results between manual CAT and automated ORTHO VISION was 97.9%. The concordance rate of cross-matching for antibody positive samples between manual CAT and the automated ORTHO VISION was 97.9%. Coombs cross-matching was efficient using ORTHO VISION, whereas saline cross-matching was efficient using the tube manual method. CONCLUSIONS: ORTHO VISION showed reliable results for cross-matching and was more efficient than manual CAT for coombs cross-matching. Thus, ORTHO VISION can be used for pre-transfusion tests in blood banks.
Agglutination ; Animals ; Automation ; Blood Banks ; Cats ; Humans ; Methods

BACKGROUND: Stenotrophomonas maltophilia has emerged as an important opportunistic pathogen, which causes infections that are often difficult to manage because of the inherent resistance of the pathogen to a variety of antimicrobial agents. In this study, we analyzed the expressions of smeABC and smeDEF and their correlation with antimicrobial susceptibility. We also evaluated the genetic relatedness and epidemiological links among 33 isolates of S. maltophilia. METHODS: In total, 33 S. maltophilia strains were isolated from patients in a tertiary hospital in Daejeon. Minimum inhibitory concentrations (MICs) of 11 antimicrobial agents were determined by using agar dilution method and E-test (BioMerieux, France). Real-time PCR analysis was performed to evaluate the expression of the Sme efflux systems in the S. maltophilia isolates. Additionally, an epidemiological investigation was performed using multilocus sequence typing (MLST) assays. RESULTS: The findings of susceptibility testing showed that the majority of the S. maltophilia isolates were resistant to beta-lactams and aminoglycosides. Twenty-one clinical isolates overexpressed smeABC and showed high resistance to ciprofloxacin. Moreover, a high degree of genetic diversity was observed among the S. maltophilia isolates; 3 sequence types (STs) and 23 allelic profiles were observed. CONCLUSIONS: The smeABC efflux pump was associated with multidrug resistance in clinical isolates of S. maltophilia. In particular, smeABC efflux pumps appear to perform an important role in ciprofloxacin resistance of S. maltophilia. The MLST scheme for S. maltophilia represents a discriminatory typing method with stable markers and is appropriate for studying population structures.
Alleles ; Anti-Infective Agents/pharmacology ; Bacterial Proteins/genetics/*metabolism ; Bacterial Typing Techniques ; Ciprofloxacin/pharmacology ; Drug Resistance, Multiple, Bacterial ; Gene Expression Regulation, Bacterial ; Gram-Negative Bacterial Infections/microbiology ; Humans ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Stenotrophomonas maltophilia/classification/drug effects/*genetics/isolation & purification

BACKGROUND: Enterococcus faecium has emerged as an important nosocomial pathogen worldwide, and this trend has been associated with the dissemination of a genetic lineage designated clonal complex 17 (CC17). In the present study, characterization of the glycopeptide resistance mechanism, genetic relatedness, and pathogenicity in isolates of vancomycin-resistant E. faecium in the Chungcheong area were investigated. METHODS: A total of 37 consecutive, non-duplicate, vancomycin-resistant E. faecium were isolated at three university hospitals in the Chungcheong area. The mechanism of glycopeptide resistance and pathogenicity factors were studied using PCR, and the genetic relatedness was determined via multilocus sequence type and esp repeat profile analysis. Additionally, the quinolone resistance-determining regions of parC and gyrA were sequenced to identify mutations involved in ciprofloxacin resistance. RESULTS: Two genotypes of VRE were confirmed: VanA-phenotype vanA genotype VRE (25 isolates) and VanB-phenotype vanA genotype VRE (12 isolates). MLST analysis revealed five sequence types. A significant result was that ST414 and CNS4 (4-1-1-1-1-1-1) were considered as belonging to CC17. The esp and hyl genes were found in 100% and 86.4% of the isolates, respectively. A total of 37 isolates showed genetic mutations in parC and gyrA. CONCLUSION: All isolated strains in the present study belonged to one of the CC17 genotypes including ST414 and CNS4 (4-1-1-1-1-1-1), which were not previously detected in Korea. The combination of MLST and the esp gene repeat profiles can be useful for genetic characterization of VREF isolates with regard to the evolutionary process and epidemiology of the clones.
Ciprofloxacin ; Clone Cells ; Enterococcus ; Enterococcus faecium ; Genotype ; Hospitals, University ; Korea ; Multilocus Sequence Typing ; Polymerase Chain Reaction ; Virulence Factors

BACKGROUND: Acinetobacter baumannii resistance islands (AbaRs) have been recently recognized as mobile genetic elements that harbor multiple resistance determinants and are associated with multidrug resistance (MDR). In the present study, we aimed to determine the AbaRs conferring multiple antimicrobial resistance and their clonal relatedness to MDR A. baumannii clinical isolates obtained from a university hospital in Daejeon, Korea. METHODS: This study included 29 MDR A. baumannii strains isolated in Daejeon, Korea. The minimal inhibitory concentrations (MICs) were determined by Etest. A. baumannii isolates were characterized using the 2 multiplex PCR assays and multilocus sequence typing (MLST) scheme. To detect and characterize AbaRs, PCR and PCR mapping experiments were performed. RESULTS: Twenty-seven of the 29 isolates belonged to the European (EU) clone II lineage and contained 5 sequence types (STs) (75, 92, 137, 138, and 357). In this study, ST357 was confirmed for the first time in Korea. Only 2 of the 29 isolates belonged to the EU clone I lineage, and were confirmed as ST109. These 2 isolates harbored the 22-kb AbaR7 aacC1-orfP-orfQ-aadA1 gene cassette array. In contrast, AbaR was not found in EU clone II isolates. CONCLUSIONS: This is the first study that attempted to determine the AbaRs in MDR A. baumannii isolates in Korea. We found 2 EU clone I isolates (ST109) that harbored AbaR7.
Acinetobacter baumannii/drug effects/*isolation & purification/metabolism ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics/metabolism ; Drug Resistance, Multiple, Bacterial/drug effects ; Humans ; Microbial Sensitivity Tests ; Multiplex Polymerase Chain Reaction ; Republic of Korea ; Sequence Analysis, DNA

BACKGROUND: Acinetobacter baumannii resistance islands (AbaRs) have been recently recognized as mobile genetic elements that harbor multiple resistance determinants and are associated with multidrug resistance (MDR). In the present study, we aimed to determine the AbaRs conferring multiple antimicrobial resistance and their clonal relatedness to MDR A. baumannii clinical isolates obtained from a university hospital in Daejeon, Korea. METHODS: This study included 29 MDR A. baumannii strains isolated in Daejeon, Korea. The minimal inhibitory concentrations (MICs) were determined by Etest. A. baumannii isolates were characterized using the 2 multiplex PCR assays and multilocus sequence typing (MLST) scheme. To detect and characterize AbaRs, PCR and PCR mapping experiments were performed. RESULTS: Twenty-seven of the 29 isolates belonged to the European (EU) clone II lineage and contained 5 sequence types (STs) (75, 92, 137, 138, and 357). In this study, ST357 was confirmed for the first time in Korea. Only 2 of the 29 isolates belonged to the EU clone I lineage, and were confirmed as ST109. These 2 isolates harbored the 22-kb AbaR7 aacC1-orfP-orfQ-aadA1 gene cassette array. In contrast, AbaR was not found in EU clone II isolates. CONCLUSIONS: This is the first study that attempted to determine the AbaRs in MDR A. baumannii isolates in Korea. We found 2 EU clone I isolates (ST109) that harbored AbaR7.
Acinetobacter baumannii/drug effects/*isolation & purification/metabolism ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics/metabolism ; Drug Resistance, Multiple, Bacterial/drug effects ; Humans ; Microbial Sensitivity Tests ; Multiplex Polymerase Chain Reaction ; Republic of Korea ; Sequence Analysis, DNA

No abstract available.
Fetal Blood

No abstract available.
Fetal Blood

BACKGROUND: The emergence of multidrug-resistant (MDR) Acinetobacter baumannii as an important opportunistic pathogen has given rise to significant therapeutic challenges in the treatment of nosocomial infections. In the present study, we assess the antibiotic resistance mechanisms of MDR A. baumannii strains by estimating the prevalence of antibiotic resistance determinants, including integrons, beta-lactamases, str genes, and gyrA and parC mutations. METHODS: Thirty-five MDR A. baumannii clinical isolates were collected from 3 Korean university hospitals over a 2-yr period. A. baumannii was confirmed by rpoB gene analysis. For each isolate, the minimal inhibitory concentrations (MICs) of 9 antibiotics were determined by the agar dilution method. PCR and DNA sequencing were used to identify the genes that potentially contribute to each resistance phenotype. RESULTS: Of the 35 MDR A. baumannii isolates examined, 7 antibiotic resistance gene determinants were detected. These resistance gene determinants included the gene bla(OXA-23), with an upstream element ISAba1 to promote increased gene expression and subsequent resistance to carbapenems, in 8 isolates (22.9%); aacA4, located within class 1 integrons, in 7 isolates (20.0%); and fluoroquinolone resistance conferred by gyrA and parC sense mutations in 31 isolates. CONCLUSIONS: Of the 35 MDR A. baumannii isolates, 26 (74.3%) from both outbreak and sporadic cases possessed at least 4 of the 7 antibiotic resistance gene determinants that give rise to the MDR phenotype. The co-occurrence of several resistance determinants may present a significant threat.
Acinetobacter baumannii/*drug effects/*genetics/isolation & purification ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*genetics ; Carbapenems/pharmacology ; Drug Resistance, Multiple, Bacterial/*genetics ; Hospitals, University ; Humans ; Integrons/genetics ; Microbial Sensitivity Tests ; Republic of Korea ; Sequence Analysis, DNA