Diagnostic Accuracy and Prognostic Relevance of Immunoglobulin Heavy Chain Rearrangement and 18F-FDG-PET/CT Compared With Unilateral Bone Marrow Trephination for Detecting Bone Marrow Involvement in Patients With Diffuse Large B-Cell Lymphoma.

BACKGROUND: In diffuse large B-cell lymphoma (DLBCL), bone marrow involvement (BMI) has an important clinical implication as a component of staging and International Prognostic Index. This study aimed to determine whether molecular analysis of immunoglobulin heavy chain (IgH) genes and positron emission tomography-computed tomography (PET/CT) could overcome the limitation of defining morphologic BMI by trephination biopsy and could increase the diagnostic accuracy or prognostic prediction. METHODS: A total of 94 de novo patients with DLBCL underwent PET/CT, polymerase chain reaction (PCR) test for detection of IgH gene rearrangement, and unilateral bone marrow (BM) trephination at diagnosis. RESULTS: A total of 9 patients (9.6%) were confirmed to present morphologic BMI (mBMI) based on trephination biopsy. On the other hand, 21 patients (22.3%) were confirmed to have IgH clonality (IgH BMI), while 16 (17.0%) were classified with BMI based on the assessment of PET/CT (PET BMI). Each IgH rearrangement PCR and PET/CT showed the high negative predictive value of detecting the BMI. However, the combined assessment of IgH rearrangement and PET/CT could increase the diagnostic accuracy and specificity with 87.2% and 97.0%, respectively. The survival outcome of patients with double positive PET BMI and IgH BMI was significantly worse than that with either single positive PET BMI or IgH BMI, and even less than patients with neither PET BMI nor IgH BMI (3-year PFS: 50.0% vs. 75.4% vs. 97.9%, P = 0.007, 3-year OS: 50.0% vs. 75.6% vs. 80.1%, P = 0.035, respectively). CONCLUSION: This study suggests that the combined evaluation of PET/CT and IgH rearrangement could give additional information for predicting therapeutic outcomes in patients with negative morphologic BMI as an important part of the prognosis.

Performance assessment of ASTA MicroIDSys, a new matrix assisted laser desorption ionization-time of flight mass spectrometry system, for identification of viridans group streptococci.

The performance of the ASTA MicroIDSys system (ASTA), a new matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) system, was evaluated for the identification of viridans group streptococci (VGS) and compared with the results obtained with the Bruker Biotyper system (Bruker Daltonics). A total of 106 Streptococcus reference strains belonging to 24 species from the bacterial strain bank was analyzed using the two MALDI-TOF MS systems. Of the 106 reference strains tested, ASTA MicroIDSys and Bruker Biotyper correctly identified 84.9% and 81.1% at the species level, 100% and 97.2% at the group level and 100% and 98.1% at the genus level, respectively. The difference between the two systems was not statistically significant (P = 0.289). Out of 24 species, 13 species were accurately identified to the species level with 100% accurate identification rates with both systems. The accurate identification rates at the species level of ASTA MicroIDSys and Bruker Biotyper were 100% and 87.5% for the S. anginosus group; 78.4% and 73.5% for the S. mitis group; 91.7% and 91.7% for the S. mutans group; and 100% and 100% for the S. salivarius group, respectively. The ASTA MicroIDSys showed an identification performance equivalent to that of the Bruker Biotyper for VGS. Therefore, it would be useful for the identification of VGS strains in clinical microbiology laboratories.

MEF2D-BCL9 B-Lymphoblastic Leukemia Blast Morphology Does Not Always Mimic Mature B-Cell Leukemia.

MEF2D (myocyte enhancer factor 2D)-rearranged acute lymphoblastic leukemia (ALL) has recently been documented by transcriptome sequencing in B-cell precursor ALL. It is associated with older age of onset (median: 14 y), and characterized by very early relapse and poorer outcomes than other B-cell precursor ALL groups. According to report by Suzuki and colleagues, all 4 cases of MEF2D-BCL9-fusion ALL among 59 children with relapsed or primary refractory ALL had leukemic blasts morphologically mimicking mature B-cell leukemia cells. However, we display morphologically different blast populations in 2 patients with MEF2D-BCL9-rearranged ALL. Mature B-cell leukemia-like morphology would aid the detection of MEF2D-BCL9 fusion, but not all cases might have typical morphology.

Evaluation of Two Commercial Broth Microdilution Methods Using Different Interpretive Criteria for the Detection of Molecular Mechanisms of Acquired Azole and Echinocandin Resistance in Four Common Candida Species.

The abilities of the new Vitek 2 AST-YS08 (YS08) and Sensititre YeastOne (SYO) systems to detect the resistances of Candida isolates to azoles and echinocandins were evaluated. In total, 292 isolates, including 28 Candida albicans (6 Erg11 and 2 Fks mutants), 57 Candida parapsilosis (26 Erg11 mutants), 24 Candida tropicalis (10 Erg11 and 1 Fks mutants), and 183 Candida glabrata (39 Pdr1 and 13 Fks mutants) isolates, were tested. The categorical agreements (CAs) between the Clinical and Laboratory Standards Institute (CLSI) method and YS08 fluconazole MICs obtained using clinical breakpoints were 92.4% (C. albicans), 96.5% (C. parapsilosis), and 87.0% (C. tropicalis), and the CAs between the CLSI and SYO MICs were 92.3% (C. albicans), 77.2% (C. parapsilosis), 100% (C. tropicalis), and 98.9% (C. glabrata). For C. glabrata, the CAs with the CLSI micafungin MICs were 92.4% and 55.5% for the YS08 micafungin and caspofungin MICs, respectively; they were 100%, 95.6%, and 98.9% for the SYO micafungin, caspofungin, and anidulafungin MICs, respectively. YS08 does not provide fluconazole data for C. glabrata; the CA with the CLSI fluconazole MIC was 97.8% for the YS08 voriconazole MIC, using an epidemiological cutoff value (ECV) of 0.5 µg/ml. Increased CAs with the CLSI MIC were observed for the YS08 MIC using CLSI ECVs (for fluconazole and C. tropicalis, 100%; for micafungin and C. glabrata, 98.9%) and for the SYO MIC using method-specific ECVs (for fluconazole and C. parapsilosis, 91.2%; for caspofungin and C. glabrata, 98.9%). Therefore, the YS08 and SYO systems may have different abilities to detect mechanisms of azole and echinocandin resistance in four Candida species; the use of method-specific ECVs may improve the performance of both systems.

Next-generation sequencing-based posttransplant monitoring of acute myeloid leukemia identifies patients at high risk of relapse.

Next-generation sequencing (NGS) has been applied to define clinically relevant somatic mutations and classify subtypes in acute myeloid leukemia (AML). Persistent allelic burden after chemotherapy is associated with higher relapse incidence, but presence of allelic burden in AML patients after receiving allogeneic hematopoietic cell transplantation (HCT) has not been examined longitudinally. As such, we aimed to assess the feasibility of NGS in monitoring AML patients receiving HCT. Using a targeted gene panel, we performed NGS in 104 AML patients receiving HCT using samples collected at diagnosis, pre-HCT, and post-HCT at day 21 (post-HCTD21). NGS detected 256 mutations in 90 of 104 patients at diagnosis, which showed stepwise clearances after chemotherapy and HCT. In a subset of patients, mutations were still detectable pre-HCT and post-HCT. Most post-HCT mutations originate from mutations initially detected at diagnosis. Post-HCTD21 allelic burdens in relapsed patients were higher than in nonrelapsed patients. Post-HCTD21 mutations in relapsed patients all expanded at relapse. Assessment of variant allele frequency (VAF) revealed that overall VAF post-HCTD21 (VAF0.2%-post-HCTD21) is associated with an increased risk of relapse (56.2% vs 16.0% at 3 years; P < .001) and worse overall survival (OS; 36.5% vs 67.0% at 3 years; P = .006). Multivariate analyses confirmed that VAF0.2%-post-HCTD21 is an adverse prognostic factor for OS (hazard ratio [HR], 3.07; P = .003) and relapse incidence (HR, 4.75; P < .001), independent of the revised European LeukemiaNet risk groups. Overall, current study demonstrates that NGS-based posttransplant monitoring in AML patients is feasible and can distinguish high-risk patients for relapse.

Xpert MTB/RIF Assay as a Substitute for Smear Microscopy in an Intermediate-Burden Setting.

RATIONALE: Use of Xpert MTB/RIF assay as a substitute for smear microscopy in routine clinical practice remains unexplored in an intermediate-tuberculosis-burden setting. OBJECTIVES: To compare the diagnostic performance of Xpert and smear microscopy, based on sampling time and location, correlation of Xpert semiquantitative category with smear grade and time to culture positivity, and compliance of reporting time with defined standard time. METHODS: Consecutive sputum samples collected from 2,952 suspected pulmonary tuberculosis patients over a 3-year period were tested by Xpert, smear microscopy, and liquid culture as part of routine diagnostics in South Korea. MEASUREMENTS AND MAIN RESULTS: Based on the analysis of a single sputum specimen per patient, of 2,952 samples, 263 (8.9%) were culture-confirmed tuberculosis and 265 (9.0%) were nontuberculous mycobacteria. The overall sensitivity and specificity were 74.1% and 97.5% for Xpert versus 38.8% and 96.7% for smear microscopy, respectively (P < 0.0001; P > 0.05). Of 82 smear-positive nontuberculous mycobacteria, 81 (98.8%) were accurately excluded by Xpert. Sampling time and location significantly affected the performance of smear microscopy but not that of Xpert. Xpert semiquantitative category strongly correlated with smear grade (γGoodman-Kruskal = 0.982; P < 0.0001) and time to culture positivity (γGoodman-Kruskal = -0.962; P < 0.0001). Median reporting time and its compliance rate within 24 hours were 3.1 hours and 96.3% for Xpert versus 19.1 hours and 88.7% for smear microscopy, respectively (P < 0.0001; P < 0.05). CONCLUSIONS: Xpert provides faster, more stable, and superior results compared with smear microscopy, in addition to its strong correlation with smear grade. Xpert might replace smear microscopy as the first-line diagnostic test for pulmonary tuberculosis in routine clinical practice in an intermediate-burden setting.

Microsatellite Typing and Resistance Mechanism Analysis of Voriconazole-Resistant Aspergillus flavus Isolates in South Korean Hospitals.

A recent surveillance study in South Korea revealed that 14% (7/50) of Aspergillus flavus clinical isolates had a voriconazole minimum inhibitory concentration of ≥4 µg/ml. Of seven non-wild-type (non-WT) isolates, six ear isolates from four hospitals shared the same microsatellite genotype. None of the non-WT isolates showed cyp51 mutations associated with azole resistance. However, the mean expression levels of efflux pump (MDR2, atrF, and mfs1) and target (cyp51A) genes exhibited significant differences between non-WT and other isolates.

Candida auris Clinical Isolates from South Korea: Identification, Antifungal Susceptibility, and Genotyping.

Candida auris is an emerging worldwide fungal pathogen. Over the past 20 years, 61 patient isolates of C. auris (4 blood and 57 ear) have been obtained from 13 hospitals in Korea. Here, we reanalyzed those molecularly identified isolates using two matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems, including Biotyper and Vitek MS, followed by antifungal susceptibility testing, sequencing of the ERG11 gene, and genotyping. With a research-use-only (RUO) library, 83.6% and 93.4% of the isolates were correctly identified by Biotyper and Vitek MS, respectively. Using an in vitro diagnostic (IVD) library of Vitek MS, 96.7% of the isolates were correctly identified. Fluconazole-resistant isolates made up 62.3% of the isolates, while echinocandin- or multidrug-resistant isolates were not found. Excellent essential (within two dilutions, 96.7%) and categorical agreements (93.4%) between the Clinical and Laboratory Standards Institute (CLSI) and Vitek 2 (AST-YS07 card) methods were observed for fluconazole. Sequencing ERG11 for all 61 isolates revealed that only 3 fluconazole-resistant isolates showed the Erg11p amino acid substitution K143R. All 61 isolates showed identical multilocus sequence typing (MLST). Pulsed-field gel electrophoresis (PFGE) analyses revealed that both blood and ear isolates had the same or similar patterns. These results show that MALDI-TOF MS and Vitek 2 antifungal susceptibility systems can be reliable diagnostic tools for testing C. auris isolates from Korean hospitals. The Erg11p mutation was seldom found among Korean isolates of C. auris, and multidrug resistance was not found. Both MLST and PFGE analyses suggest that these isolates are genetically similar.

Identification of new aryl hydrocarbon receptor (AhR) antagonists using a zebrafish model.

A new series of 1,3-diketone, heterocyclic and α,ß-unsaturated derivatives were synthesized and evaluated for their AhR antagonist activity using zebrafish and mammalian cells. Compounds 1b, 2c, 3b and 5b showed significant AhR antagonist activity in a transgenic zebrafish model. Among them, compound 3b, and 5b were found to have excellent AhR antagonist activity with IC50 of 3.36 nM and 8.3 nM in a luciferase reporter gene assay. In stem cell proliferation assay, compound 5b elicited marked HSC expansion.

A longitudinal study of the associations of BDNF genotype and methylation with poststroke anxiety.

BACKGROUND: Although the precise etiology of poststroke anxiety (PSA) has yet to be fully elucidated, it is known that brain-derived neurotrophic factor (BDNF) is important for neural plasticity and long-term potentiation, associated with the pathophysiology of anxiety. The expression of BDNF is regulated by epigenetic and genetic profiles. Thus, we investigated the association between BDNF methylation status and PSA at 2 weeks and 1 year after stroke while accounting for interactions with the BDNF Val66Met polymorphism. METHODS: The baseline sample comprised 286 patients who were assessed at 2 weeks after stroke; of these patients, 222 (78%) were followed up with at 1 year after stroke. The presence of PSA was determined using the anxiety subscale of the Hospital Anxiety and Depression Scale (HADS), and the effects of BDNF methylation status and polymorphisms on PSA status were assessed with multivariate logistic regression models. RESULTS: The prevalence of PSA was slightly lower (27 [9.4%]) at baseline, and 35 (15.8%) patients were identified as having PSA at the 1-year follow-up. Stroke patients with a higher average methylation status were more likely to have PSA at 1 year. The BDNF Val66Met polymorphism was not independently associated with PSA during either the acute or chronic phase after stroke, but there was a significant interactive effect between BDNF methylation and genotype on PSA at 2 weeks. CONCLUSIONS: In this study, BDNF methylation in combination with the met/met BDNF polymorphism (Val66Met polymorphism) was associated with PSA. These findings may help identify patients at higher risk for PSA.

Fluconazole-Resistant Candida parapsilosis Bloodstream Isolates with Y132F Mutation in ERG11 Gene, South Korea.

We recently observed the emergence of fluconazole-resistant Candida parapsilosis bloodstream isolates harboring a Y132F substitution in Erg11p in South Korea. These Y132F isolates had a higher propensity to cause clonal transmission than other fluconazole-resistant isolates and persisted within hospitals for several years, as revealed by microsatellite typing.

Molecular Diagnosis of Taenia saginata Tapeworm Infection in 2 Schoolchildren, Myanmar.

Taenia saginata is the most common human tapeworm worldwide but has been unknown in Myanmar. In 2017, fecal examination in Yangon, Myanmar, revealed eggs of Taenia species in 2 children from a monastic school. Several proglottids expelled after medication with praziquantel were morphologically and molecularly confirmed to be T. saginata tapeworms.

Antifungal susceptibilities to amphotericin B, triazoles and echinocandins of 77 clinical isolates of cryptic Aspergillus species in multicenter surveillance in Korea.

We investigated the in vitro antifungal susceptibilities of cryptic Aspergillus species from nine Korean hospitals. Based on the CLSI epidemiological cutoff values, resistance rates to amphotericin B, itraconazole, voriconazole, posaconazole and caspofungin were as follows: A. awamori (34 isolates; all 0%), A. tubingensis (22; 0%, 4.5%, 0%, 0%, and 0%, respectively), A. sydowii (16; 0%, 6.3%, 0%, 0%, and 6.3%), A. lentulus (2; 50%, 0%, 100%, 50%, and 0%), and A. tamarii (2; all 0%). A. calidoustus (one isolate) showed resistance to multiple drugs. Thus, cryptic species identification can be mandatory for clinically important Aspergillus isolates, with their susceptibility data.

The Impact of Tumor Necrosis Factor-α and Interleukin-1ß Levels and Polymorphisms on Long-Term Stroke Outcomes.

BACKGROUND: The accuracy of predictions regarding disability that sets in after stroke could be improved by using blood biomarker measurements. This study aimed to investigate the roles of serum tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1ß concentrations and polymorphisms in stroke outcomes. METHODS: In total, 286 patients were evaluated at the time of admission and at 2 weeks after stroke, and 222 of these patients (78%) were followed up for 1 year to evaluate the consequences of stroke during both the acute and chronic stages. Stroke outcomes were dichotomized into good and poor using the modified Rankin Scale. RESULTS: The association of TNF-α and IL-1ß concentrations and their corresponding genotypes with stroke outcomes was investigated using multivariate logistic regression. Higher TNF-α levels were associated with poor outcomes 1 year after stroke in the presence of the -850T and -308A alleles, and IL-1ß levels were associated with poor 1-year stroke outcomes in the presence of the -511T and +3953T alleles. No such associations were found at 2 weeks after stroke. CONCLUSIONS: These data provide evidence that serum TNF-α and IL-1ß concentrations are related to poor long-term outcomes after stroke in the presence of particular alleles.

Resistance Mechanisms and Clinical Features of Fluconazole-Nonsusceptible Candida tropicalis Isolates Compared with Fluconazole-Less-Susceptible Isolates.

We investigated the azole resistance mechanisms and clinical features of fluconazole-nonsusceptible (FNS) isolates of Candida tropicalis recovered from Korean surveillance cultures in comparison with fluconazole-less-susceptible (FLS) isolates. Thirty-five clinical isolates of C. tropicalis, comprising 9 FNS (fluconazole MIC, 4 to 64 µg/ml), 12 FLS (MIC, 1 to 2 µg/ml), and 14 control (MIC, 0.125 to 0.5 µg/ml) isolates, were assessed. CDR1, MDR1, and ERG11 expression was quantified, and the ERG11 and UPC2 genes were sequenced. Clinical features of 16 patients with FNS or FLS bloodstream isolates were analyzed. Both FNS and FLS isolates had >10-fold higher mean expression levels of CDR1, MDR1, and ERG11 genes than control isolates (P values of <0.02 for all). When FNS and FLS isolates were compared, FNS isolates had 3.4-fold higher mean ERG11 expression levels than FLS isolates (P = 0.004), but there were no differences in those of CDR1 or MDR1 Of all 35 isolates, 4 (2 FNS and 2 FLS) and 28 (8 FNS, 11 FLS, and 9 control) isolates exhibited amino acid substitutions in Erg11p and Upc2p, respectively. Both FNS and FLS bloodstream isolates were associated with azole therapeutic failure (3/4 versus 4/7) or uncleared fungemia (4/6 versus 4/10), but FNS isolates were identified more frequently from patients with previous azole exposure (6/6 versus 3/10; P = 0.011) and immunosuppression (6/6 versus 3/10; P = 0.011). These results reveal that the majority of FNS C. tropicalis isolates show overexpression of CDR1, MDR1, and ERG11 genes, and fungemia develops after azole exposure in patients with immunosuppression.

Thalidomide-based induction regimens are as effective as bortezomib-based regimens in elderly patients with multiple myeloma with cereblon expression.

Cereblon (CRBN) has been identified as a primary target of immunomodulatory drugs and is considered a biomarker for the prediction of outcomes after thalidomide- or lenalidomide-based treatments. In this study, we evaluated CRBN expression in bone marrow (BM) tissue at diagnosis and investigated the relationship between CRBN expression and treatment outcomes after thalidomide- or bortezomib-based front-line therapies in 89 elderly patients with multiple myeloma (MM). CRBN expression at the time of diagnosis was evaluated with immunohistochemical (IHC) staining for myeloma cells in paraffin wax-embedded BM tissue. CRBN-immunostained slides were scored by intensity and diffuseness, and a total score of >6 was defined as CRBN-positive (CRBN(+)). Thirty-eight patients (45.2 %) were CRBN(+). Among patients treated with thalidomide-based regimens, CRBN(+) patients showed a better treatment response than did CRBN-negative patients (35.0 vs. 11.8 % complete response rate, respectively; HR = 4.038, P = 0.137). During a median follow-up of 31.8 months, patients treated with bortezomib-based regimens had a longer time to progression (TTP) than did patients treated with thalidomide-based regimens (15.6 vs. 13.2 months, respectively; P = 0.047), but early mortality occurred frequently in patients treated with bortezomib-based regimens. Additionally, there was no significant difference in survival outcomes between thalidomide- and bortezomib-based regimens in CRBN(+) patients (median TTP, 13.8 vs. 15.6 months, respectively; P = 0.842 and median OS, 39.3 vs. 30.1 months, respectively; P = 0.074). These data suggest that thalidomide-based regimens are as effective as bortezomib-based regimens in elderly patients with MM who are CRBN(+). Thus, CRBN positivity, by IHC staining, may be useful in deciding appropriate treatment options in elderly patients with MM.

Direct confirmation of quiescence of CD34+CD38- leukemia stem cell populations using single cell culture, their molecular signature and clinicopathological implications.

BACKGROUND: The proliferating activity of a single leukemia stem cell and the molecular mechanisms for their quiescent property remain unknown, and also their prognostic value remains a matter of debate. Therefore, this study aimed to demonstrate the quiescence property and molecular signature of leukemia stem cell and their clinicopathological implications. METHODS: Single cell sorting and culture were performed in the various sets of hematopoietic stem cells including CD34+CD38- acute myeloid leukemia (AML) cell population (ASCs) from a total of 60 patients with AML, and 11 healthy controls. Their quiescence related-molecular signatures and clinicopathological parameters were evaluated in AML patients. RESULTS: Single cell plating efficiency of ASCs was significantly lower (8.6%) than those of normal hematopoietic stem cells i.e.: cord blood, 79.0%; peripheral blood, 45.3%; and bone marrow stem cell, 31.1%. Members of the TGFß super-family signaling pathway were most significantly decreased; as well as members of the Wnt, Notch, pluripotency maintenance and hedgehog pathways, compared with non ASC populations. mtDNA copy number of ASCs was significantly lower than that of corresponding other cell populations. However, our data couldn't support the prognostic value of the ASCs in AML. CONCLUSIONS: ASCs showed remarkable lower plating efficiency and slower dividing properties at the single cell level. This quiescence is represented as a marked decrease in the mtDNA copy number and also linked with down-regulation of genes in various molecular pathways.

The prognostic impact of mutations in spliceosomal genes for myelodysplastic syndrome patients without ring sideroblasts.

BACKGROUND: Mutations in genes that are part of the splicing machinery for myelodysplastic syndromes (MDS), including MDS without ring sideroblasts (RS), have been widely investigated. The effects of these mutations on clinical outcomes have been diverse and contrasting. METHODS: We examined a cohort of 129 de novo MDS patients, who did not harbor RS, for mutations affecting three spliceosomal genes (SF3B1, U2AF1, and SRSF2). RESULTS: The mutation rates of SF3B1, U2AF1, and SRSF2 were 7.0 %, 7.8 %, and 10.1 %, respectively. Compared with previously reported results, these rates were relatively infrequent. The SRSF2 mutation strongly correlated with old age (P < 0.001), while the mutation status of SF3B1 did not affect overall survival (OS), progression-free survival (PFS), or acute myeloid leukemia (AML) transformation. In contrast, MDS patients with mutations in U2AF1 or SRSF2 exhibited inferior PFS. The U2AF1 mutation was associated with inferior OS in low-risk MDS patients (P = 0.035). The SRSF2 mutation was somewhat associated with AML transformation (P = 0.083). CONCLUSION: Our findings suggest that the frequencies of the SF3B1, U2AF1, and SRSF2 splicing gene mutations in MDS without RS were relatively low. We also demonstrated that the U2AF1 and SRSF2 mutations were associated with an unfavorable prognostic impact in MDS patients without RS.

Feasible quantitative detection of cytomegalovirus from urine sediment in stem cell transplant patients.

BACKGROUND: Urine is an important source for the detection of infections caused by CMV in stem cell transplant patients. Currently, there is no agreement about the type of urine specimen. In order to investigate which is the better specimen type for quantitative detection of CMV, we compared the results from urine supernatant and sediment from the same patients. METHODS: Seventy urine specimens were collected from patients with hematological disorders or solid tumors. After performing shell vial culture, residual urine specimens were centrifuged. Then, 10 mL of each urine supernatant and sediment were taken and immediately frozen at -70 degrees C. Afterwards, archived urine specimens were thawed at room temperature and CMV-quantitative PCR was performed on both the supernatant and sediment fraction of urine. The results from each patient were reviewed for CMV antigenemia, blood shell vial culture, CMV-IgM or IgG, and clinical symptoms. RESULTS: CMV-qPCR results for the urine sediment fraction revealed a significant difference (p = 0.012) between the active CMV infection group and the latent CMV infection group. In addition, receiver operating characteristic curves for active CMV infection revealed that CMV-qPCR using urine sediment produced more accurate results than urine supernatant. CONCLUSIONS: These findings suggest that the sediment fraction of urine is a more suitable specimen in CMV-qPCR testing.

Identification, genotypic relation, and clinical features of colistin-resistant isolates of Acinetobacter genomic species 13BJ/14TU from bloodstreams of patients in a university hospital.

Colistin resistance remains rare among clinical isolates of Acinetobacter species. We noted the emergence of colistin-resistant bloodstream isolates of the Acinetobacter genomic species (GS) 13BJ/14TU from patients at a university hospital between 2003 and 2011. We report here, for the first time, the microbiological and molecular characteristics of these isolates, with clinical features of Acinetobacter GS 13BJ/14TU bacteremia. All 11 available patient isolates were correctly identified as Acinetobacter GS 13BJ/14TU using partial rpoB gene sequencing but were misidentified using the phenotypic methods Vitek 2 (mostly as Acinetobacter baumannii), MicroScan (mostly as A. baumannii/Acinetobacter haemolyticus), and the API 20 NE system (all as A. haemolyticus). Most isolates were susceptible to commonly used antibiotics, including carbapenems, but all were resistant to colistin, for which it is unknown whether the resistance is acquired or intrinsic. However, the fact that none of the patients had a history of colistin therapy strongly suggests that Acinetobacter GS 13BJ/14TU is innately resistant to colistin. The phylogenetic tree of multilocus sequence typing (MLST) showed that all 11 isolates formed a separate cluster from other Acinetobacter species and yielded five sequence types. However, pulsed-field gel electrophoresis (PFGE) revealed 11 distinct patterns, suggesting that the bacteremia had occurred sporadically. Four patients showed persistent bacteremia (6 to 17 days), and all 11 patients had excellent outcomes with cleared bacteremia, suggesting that patients with Acinetobacter GS 13BJ/14TU-associated bacteremia show a favorable outcome. These results emphasize the importance of precise species identification, especially regarding colistin resistance in Acinetobacter species. In addition, MLST offers another approach to the identification of Acinetobacter GS 13BJ/14TU, whereas PFGE is useful for genotyping for this species.