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

When dysfunction of two or more endocrine glands occurs in association with circulating organ specific antibodies directed against the involved glands, the term polyglandular autoimmune (PGA) syndrome is applied. This syndrome is usually classified into three groups. The autoimmune nature of this disease has been based on the presence of lymphocytic infiltration of the affected glands, organ specific autoantibody in serum, cellular immune defects and association with HLA DR/DQ genes. A 12-year-old girl developed PGA syndrome, type III manifesting Grave's disease and insulin-dependent diabetes mellitus. The thyroid microsomal Ab, TSH receptor Ab and pancreatic islet cell Ab were positive. She should be observed for the possible development of adrenal insufficiency and/or other autoimmune disease.
Adrenal Insufficiency ; Antibodies ; Autoimmune Diseases ; Child ; Diabetes Mellitus, Type 1 ; Endocrine Glands ; Female ; Humans ; Islets of Langerhans ; Receptors, Thyrotropin ; Thyroid Gland

Acinetobacter baumannii is an important microorganism responsible for a number of nosocomial outbreaks, in particular, in intensive care units (ICUs). We investigated a nosocomial infection caused by multidrug-resistant (MDR) A. baumannii in a neonatal intensive care unit (NICU) in Korea. A. baumannii isolates were characterized using Etest (AB Biodisk, Sweden), two multiplex PCR assays, and multilocus sequence typing (MLST) scheme. PCR and PCR mapping experiments were performed for detecting and characterizing the determinants of antimicrobial resistance. Eight strains isolated from an NICU belonged to European (EU) clone II and revealed only one sequence type (ST), namely, ST357. All the isolates were susceptible to imipenem but were resistant to amikacin, gentamicin, ceftazidime, cefepime, and ciprofloxacin. To the best of our knowledge, this is the first report of a nosocomial infection in an NICU in Korea caused by ST357 MDR/carbapenem-susceptible A. baumannii strains. This result demonstrates that nosocomial outbreaks of MDR/carbapenem-susceptible strains as well as MDR/carbapenem-resistant isolates may occur in NICUs.
Acinetobacter Infections/diagnosis/*microbiology ; Acinetobacter baumannii/drug effects/genetics/*isolation & purification/metabolism ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics ; Cross Infection/*microbiology ; DNA, Bacterial/analysis ; *Drug Resistance, Multiple, Bacterial ; Humans ; Imipenem/pharmacology ; Infant, Newborn ; *Intensive Care Units, Neonatal ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Multiplex Polymerase Chain Reaction ; Republic of Korea

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: Members of the Acinetobacter calcoaceticus-baumannii (Acb) complex are important opportunistic bacterial pathogens and present significant therapeutic challenges in the treatment of nosocomial infections. In the present study, we investigated the integrons and various genes involved in resistance to carbapenems, aminoglycosides, and fluoroquinolones in 56 imipenem-nonsusceptible Acb complex isolates. METHODS: This study included 44 imipenem-nonsusceptible A. baumannii, 10 Acinetobacter genomic species 3, and 2 Acinetobacter genomic species 13TU strains isolated in Daejeon, Korea. The minimum inhibitory concentrations (MICs) were determined by Etest. PCR and DNA sequencing were used to identify the genes that potentially contribute to each resistance phenotype. RESULTS: All A. baumannii isolates harbored the blaOXA-51-like gene, and 21 isolates (47.7%) co-produced OXA-23. However, isolates of Acinetobacter genomic species 3 and 13TU only contained blaIMP-1 or blaVIM-2. Most Acb complex isolates (94.6%) harbored class 1 integrons, armA, and/or aminoglycoside-modifying enzymes (AMEs). Of particular note was the fact that armA and aph(3')-Ia were only detected in A. baumannii isolates, which were highly resistant to amikacin (MIC50> or =256) and gentamicin (MIC50> or =1,024). In all 44 A. baumannii isolates, resistance to fluoroquinolones was conferred by sense mutations in the gyrA and parC. However, sense mutations in parC were not found in Acinetobacter genomic species 3 or 13TU isolates. CONCLUSIONS: Several differences in carbapenem, aminoglycoside, and fluoroquinolone resistance gene content were detected among Acb complex isolates. However, most Acb complex isolates (87.5%) possessed integrons, carbapenemases, AMEs, and mutations in gyrA. The co-occurrence of several resistance determinants may present a significant threat.
Acinetobacter Infections/microbiology ; Acinetobacter baumannii/*genetics/isolation & purification ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; DNA Gyrase/genetics ; DNA, Bacterial/chemistry/genetics ; Drug Resistance, Bacterial/*genetics ; Humans ; Imipenem/*pharmacology ; Integrons/genetics ; Methyltransferases/genetics ; Microbial Sensitivity Tests ; Mutation ; Polymerase Chain Reaction ; Republic of Korea ; Sequence Analysis, DNA ; beta-Lactamases/biosynthesis/genetics

BACKGROUND: Multidrug-resistant Enterobacteriaceae is a worldwide problem. Although various resistance mechanisms have been recognized with increasing frequency, only a few cases of triple resistance of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae have been reported. This study was designed to evaluate the coexistence of qnr (qnrA, qnrB, and qnrS) and 16S rRNA methylase (armA, rmtA, rmtB, and rmtC) in ESBL-producing K. pneumoniae. METHODS: We tested 44 isolates of ESBL-producing K. pneumoniae at Chungnam National University Hospital from March to September 2006. Antimicrobial susceptibilities were tested by broth microdilution method, and transconjugation test was performed using E. coli J53 with azide resistance. Search for qnr (qnrA, qnrB, and qnrS) and 16S rRNA methylase (armA, rmtA, rmtB, and rmtC) genes was conducted by PCR amplification, and the genotypes were determined by direct nucleotide sequence analysis of the amplified products. Epidemiologic study was performed by Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). RESULTS: All ESBL-positive strains produced qnrB; however, armA was detected in 68.2%. The coproduction rate of qnrB and armA in ESBL-producing K. pneumoniae was 68.2%. Two types (A and B) were dominant in ERIC-PCR results. CONCLUSIONS: K. pneumoniae producing qnrB, armA, and ESBL are spreading widely.
Bacterial Proteins/biosynthesis/*genetics ; Disk Diffusion Antimicrobial Tests ; Drug Resistance, Bacterial/genetics ; Humans ; Klebsiella Infections/microbiology ; Klebsiella pneumoniae/drug effects/*genetics/isolation & purification ; Methyltransferases/biosynthesis/*genetics ; beta-Lactamases/biosynthesis/drug effects/*genetics

We report a case of a 13-year-old girl with acute lymphoblastic lymphoma-leukemia, who presented with a cardiac metastasis in the right ventricle, resulting in a pulmonary embolism. At the time of her leukemia diagnosis, a cardiac mass was incidentally found. The differential diagnosis for this unusual cardiac mass included cardiac tumor, metastasis, vegetation, and thrombus. Empirical treatment was initiated, including anticoagulation and antibiotics. She underwent plasmapheresis and was administered oral prednisolone for her leukemia. Five days later, she experienced sudden hemodynamic collapse and required extracorporeal membrane oxygenation insertion and emergency surgery. These interventions proved futile, and the patient died. Pathology revealed that the cardiac mass comprised an aggregation of small, round, necrotic cells consistent with leukemia. This is the first known case of acute lymphoblastic leukemia presenting as a right ventricular mass, with consequent fatal acute pulmonary embolism. A cardiac mass in a child with acute leukemia merits investigation to rule out every possible etiology, including vegetation, thrombus, and even a mass of leukemic cells, which could result in the fatal complication of pulmonary embolism.
Adolescent ; Anti-Bacterial Agents ; Child ; Diagnosis, Differential ; Emergencies ; Extracorporeal Membrane Oxygenation ; Heart Neoplasms ; Heart Ventricles ; Hemodynamics ; Humans ; Leukemia ; Neoplasm Metastasis ; Plasmapheresis ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Prednisolone ; Pulmonary Embolism ; Thrombosis

Carbapenemase production has been reported worldwide in gram-negative bacteria, including Acinetobacter species. We detected carbapenemase-producing Acinetobacter pittii in clinical isolates in Daejeon, Korea. Twenty-one ertapenem-resistant A. pittii isolates screened with a disk diffusion method were characterized by using the Epsilon test, four multiplex PCR assays, and a multilocus sequence typing (MLST) scheme. A total of 21 A. pittii isolates harbored the metallo-beta-lactamase (MBL) gene bla(IMP-1) or bla(NDM-1). Nineteen isolates containing bla(IMP-1) were resistant to imipenem and meropenem, but two isolates harboring bla(NDM-1) were susceptible to them. The sequence types (STs) of the two New Delhi MBL (NDM-1)-producing A. pittii isolates were ST70 and ST207, which differed from the STs (ST63, ST119, ST396, and a novel ST) of the IMP-1-producing A. pittii. This is the first report on NDM-1-producing A. pittii isolates in Korea. Our results emphasize that the study of NDM-1-producing gram-negative bacteria should involve carbapenem-susceptible as well as carbapenem-resistant isolates.
Acinetobacter* ; Diffusion ; Gram-Negative Bacteria ; Imipenem ; Korea ; Multilocus Sequence Typing ; Multiplex Polymerase Chain Reaction