Comparison of Red Blood Cell, White Blood Cell and Differential Counts between UF-5000 System and Manual Method

BACKGROUND: Analysis of body fluids provides important information for assessing various medical conditions. We aimed to validate the analytical and diagnostic performance of the Sysmex UF-5000 (Sysmex, Japan) system for the analysis of different body fluids. METHODS: Eighty body fluid samples were analyzed using the UF-5000 system in the body fluid mode and light microscopy. Body fluids included ascitic, pleural, and cerebrospinal fluid (CSF), as well as other fluid samples. RESULTS: A comparison between the UF-5000 system and manual counting demonstrated good correlations with regard to red (r=0.6555) and white blood cell (r=0.9666) counts. The UF-5000 system also demonstrated good performance for differential cell counting (r=0.9028). CSF particularly showed a good correlation. CONCLUSIONS: The use of the UF-5000 system for cell counting and differential analysis of body fluid samples might be an effective and automated alternative to chamber counting in laboratory routine analysis, thereby enhancing laboratory workflow and clinical effectiveness.

Performance Evaluation of the CRE2 Reagent from Siemens for Serum Creatinine Measurement

BACKGROUND: For creatinine measurement, the enzymatic method is known to be more accurate than the Jaffe method; however, the latter is still widely used. We evaluated the performance of the CRE2 reagent (Siemens Healthcare Diagnostics Inc., USA), which uses a modified Jaffe method. METHODS: Three quality control standards were used for precision evaluations of CRE2 on Dimension VISTA 500 instrument (Siemens). Moreover, the linearity and carryover characteristics were assessed. Sixty-eight creatinine results obtained using the CRE2 and ECREA (enzymatic) reagents (Siemens) were compared with those obtained using the L-CRE (enzymatic) reagent (Shinyang Diagnostics, Korea). The accuracy of CRE2, ECREA, and L-CRE was evaluated using a standard reference material. RESULTS: The CV of within-run (0.7–2.4%), between-run (0.4–1.7%), between-day precision (0.7–0.9%) for three standards, and total CV for medium (1.6%) and high levels (1.3%) satisfied the analytical goal. The linearity for CRE2 was excellent (R2=0.999). Comparisons of CRE2 and ECREA to L-CRE were well correlated (r=0.996 and 0.997, respectively). In comparison with L-CRE, 5 CRE2 results and 15 ECREA results exceeded minimum bias goal (5.1%) in samples with creatinine levels of >1 mg/dL. The carryover rate was −0.04%. In terms of accuracy, the percent bias values of CRE2, ECREA, and L-CRE were 7.4, −6.4, and −3.4, respectively, for low level; and 3.9, −1.5, and 0.7, respectively, for high level. CONCLUSIONS: For creatinine measurements, the CRE2 reagent showed good performance. It can be used in the diagnosis, treatment monitoring, and risk assessment of kidney diseases.

Evaluation of the Automated Cross-Matching Instrument, ORTHO VISION, for Use in Blood Banks

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.

Biological and Genetic Characteristics of Clinically Isolated Enterobacter cloacae with Multidrug Resistance

BACKGROUND: From January 2014 to December 2015, 69 clones of Enterobacter cloacae showing multidrug resistance to six classes of antimicrobial agents were collected from two medical centers in Korea. METHODS: Minimum inhibitory concentrations were determined using the E-test method, and 17 genes were detected using polymerase chain reaction (PCR). The epidemiological relatedness of the strains was identified using repetitive element sequence-based PCR and multilocus sequence typing. RESULTS: The 69 E. cloacae clones produced extended spectrum β lactamase (ESBL) and AmpC and showed multidrug resistance to cefotaxime, ceftazidime, and aztreonam. We identified the following sequence types: ST56 of type VI for ESBL SHV (N=12, 17.4%); ST53, ST114, ST113, and ST550 of types I, IV, VI, and VII, respectively, for CTX-M (N=11, 15.9%); and ST668 of type III for the carbapenemase NDM gene (N=1, 1.5%). The AmpC DHA gene (N=2, 2.89%) was confirmed as ST134, although its type was not identified, whereas EBC (MIR/ACT; N=18, 26.1%) was identified as ST53, ST24, ST41, ST114, ST442, ST446, ST484, and ST550 of types V, I, III, IV, VII, and VI, respectively. The formed subclasses were bla CTX-M-3 and bla CTX-M-22 by CTX-M-1, bla CTX-M-9 and bla CTX-M-125 by CTX-M-9, bla DHA-1 by DHA, and bla MIR-7 and bla ACT-15,17,18,25,27,28 by EBC (MIR/ACT). CONCLUSIONS: There were no epidemiological relationships between the gene products and the occurrence of resistance among the strains.

The Usefulness of Hematological Parameters for Assessing Disease Progression in Patients with HIV Infection

BACKGROUND: In patients with HIV, CD4+ T cell count and viral load are the main laboratory tests performed to assess clinical management. However, they require extensive resources. In this study, we aimed to determine whether hematological parameters measured using a hematology analyzer are useful as surrogate markers of CD4+ T cell count and viral load in HIV-infected patients. METHODS: Peripheral blood samples were obtained from 14 HIV-naïve, 105 HIV-treated, and 103 uninfected individuals. Hematological parameters were measured using the ADVIA 2120i hematology analyzer (Siemens Healthcare Diagnostics, USA). RESULTS: In HIV-naïve and -treated patients, the percentage of large unstained cells (%LUCs) was 2.5±1.6% and 1.9±0.7%, respectively, compared to 1.6±0.5% in HIV-uninfected controls. The %LUCs was higher in HIV patients with low CD4⁺ T cell count below 200/μL (2.4±1.0%) or high viral load ≥200 copies/mL (2.4±0.8%) than in other infected groups. Significant differences in lymphocyte count were observed between the HIV-naïve (1.5±0.6×10⁹/L) and uninfected (2.0±0.6×10⁹/L) groups as well as between HIV patients with CD4⁺ T cells ≥500/μL (2.5±0.6×10⁹/L) and other infected groups. Neutrophil count varied between high viral load (3.0±1.4×10⁹/L) and low viral load (3.7±1.3×10⁹/L) groups. The CD4⁺ T cell count correlated with lymphocyte count (r=0.642, P<0.0001) and %LUCs (r=-0.287, P=0.002). CONCLUSIONS: %LUCs, lymphocyte count, and neutrophil count are probable surrogate markers of CD4⁺ T cells and viral load.

Evaluation of the Automated Blood Bank Systems IH-500 and VISION Max for ABO-RhD Blood Typing and Unexpected Antibody Screening

BACKGROUND: The use of automated systems for pre-transfusion tests is increasing in an attempt to reduce workload and the impact of human errors in blood banks. We evaluated the clinical performance of the automated blood bank systems IH-500 (Bio-Rad Laboratories, Switzerland) and VISION Max (Ortho-Clinical Diagnostics, USA) for ABO-RhD blood typing and unexpected antibody screening. METHODS: ABO-RhD blood typing was performed for 410 samples, and antibody screening was performed for 332 samples, including 15 antibody-positive samples. The results obtained from the two automated instruments were compared with those obtained using manual methods for ABO-RhD blood typing and a semiautomated method (DiaMed-ID system) for antibody screening. Additionally, both instruments were evaluated in terms of concordance rates, sensitivity, and carryover. RESULTS: The concordance rate of the ABO-RhD blood typing results between the manual methods and the two automated instruments was 100%. For antibody screening tests, the concordance rates between the semiautomated method (DiaMed-ID system) and the automated methods were 100% and 99.7% for the IH-500 and VISION Max instruments, respectively. The sole discrepant result was obtained for a sample identified as antibody-positive only on the VISION Max; the antibody was identified as anti-Le(a). The overall sensitivity of the two automated instruments was the same as or higher than that of the semiautomated method. Carryover was not observed in antibody screening. CONCLUSIONS: The IH-500 and VISION Max instruments showed reliable results for ABO-RhD blood typing and unexpected antibody screening, and can be used clinically, with confidence, for pre-transfusion tests in the blood bank.

External Quality Assessment of Institutions and Instruments Using a Linear Mixed Model

BACKGROUND: External quality assessment (EQA) uses a standard deviation index (SDI), based on a peer group, to evaluate laboratory performance. However, evaluations using peer group SDIs often have limited applicability, because they are not statistically valid unless the number of institutions in the same peer group is large. The present study proposes a statistical model for simultaneously evaluating the performance of all participating institutions, as well as the performance of instruments on the market. METHODS: By assuming that proficiency test results were affected by the manufacturer, the instrument, and the institution, the effects of those factors were estimated using a linear mixed model. We used these effect estimates to calculate manufacturer, instrument, and institution SDIs. Using simulation, we evaluated the false positive rates and efficiencies of the proposed linear mixed model. RESULTS: Simulations showed that the linear mixed model empirical type I error rates preserved the nominal significance level. This model was also more statistically efficient than the peer group SDI. Rates of unacceptability were lower when using institution SDI than they were when using peer group SDI. Additional outliers that could not be evaluated using the current system were detected by the institution SDI statistic. The instrument SDI statistic detected outliers among different instrument groups. CONCLUSIONS: Institution and instrument SDIs are robust and efficient tools for EQA, and they can replace the currently used system of peer group SDI.

Evaluation of Automated Specimen Inoculation for Blood Culture Samples by Use of the Previ Isola(R) System Compared with the Manual Method

BACKGROUND: Recently, a new automated inoculating instrument, Previ Isola(R) (bioMerieux, France) was introduced. Although there are many evaluation reports about the inoculation of urine and body fluid samples using Previ Isola(R), no evaluation has been reported for blood samples. The objectives of this study were to evaluate this instrument for the inoculation of blood samples and to compare the microbiological results with the manual loop-to-plate method. METHODS: From March 2014 to July 2014, a total of 296 non-duplicate blood samples showing positive signals on the BacT/Alert 3D system were obtained, and both manual and automated methods were used for sample inoculation. Results of the two methods were compared according to five aspects: the culture result, number of single colonies, morphology of colonies, number of re-inoculations, and time required for inoculation. RESULTS: The sensitivity and specificity of Previ Isola(R) were 98.9% and 96.6%, respectively. The positive and negative predictive values were 99.6% and 90.3%, respectively, and the total concordance rate was 98.6%. For Previ Isola(R) and the manual methods, the number of average usable single colonies per plate was 25 and 16, the number of re-inoculations was 60 and 62, and the inoculation time for 15 blood samples was 30 min and 75 min, respectively. The morphology of colonies showed no differences between the two methods. CONCLUSIONS: The automated inoculation instrument, Previ Isola(R), showed relative good concordance with manual method, with high sensitivity and high specificity for blood sample inoculation. Previ Isola(R) may be useful for inoculating specimens including blood samples.

A Case of Roseomonas Infection in Korea

Roseomonas is a genus of pink-pigmented, oxidative, gram-negative coccobacilli and rarely causes opportunistic infection. We report a case of wound infection by Roseomonas species in a 53-yr-old man with alcoholic liver cirrhosis. 16S ribosomal RNA (rRNA) gene sequencing was performed to confirm the infectious agent. The patient recovered without complication after ciprofloxacin treatment. To the best of our knowledge, this is the first case of Roseomonas infection reported in Korea.

Performance Evaluation of the HM-JACKarc Analyser for Fecal Occult Blood Test

BACKGROUND: Fecal occult blood tests have been widely used as a means of gastrointestinal bleeding and colorectal cancer screening. HM-JACKarc (Kyowa Medex Co. Ltd, Japan) is a recently introduced automated fecal occult blood test analyser, which uses latex agglutination method. We evaluated the analytical performance of HM-JACKarc. METHODS: The linearity and precision for HM-JACKarc were evaluated according to the corresponding Clinical and Laboratory Standard Institute guidelines. The comparison study between HM-JACKarc and OC-SENSOR DIANA (Eiken Chemical Co. Ltd., Japan) was done with stool specimens. RESULTS: The linearity was good (R²=0.999) and the coefficients of variation of within-day precision and between-day precision were 5.2% and 4.9%, respectively, in low concentration and 2.7% each in high concentration. The concordance rate between HM-JACKarc and OCSENSOR DIANA was 99.0% (198 out of 200). CONCLUSIONS: HM-JACKarc showed excellent performance in linearity, precision, and comparison studies. Therefore, it appears to be a useful automated fecal occult blood test analyser.

Association between Glycemic Control and Hematologic Indices in Type 2 Diabetic Patients

BACKGROUND: Diabetes mellitus (DM) is characterized by impaired glucose regulation and various complications. It is known that chronic inflammation and platelet activation play a role in development of insulin resistance or diabetic complications. This study investigated whether hematologic parameters are useful for monitoring blood glucose regulation or complications in DM patients. METHODS: Total 90 diabetic patients were divided into two groups according to their hemoglobin A1c (HbA1c) levels: 59 regulated DM patients with HbA1c levels<7% and 31 unregulated DM patients with HbA1c levels≥7%. RESULTS: White blood cell counts (P=0.021), neutrophil counts (P=0.005), monocyte counts (P=0.040), neutrophil % (P=0.042) and the neutrophil lymphocyte ratio (NLR) (P=0.032) were significantly higher in the unregulated DM group compared to that in the regulated DM group. There were no differences in lymphocyte counts, lymphocyte %, monocyte %, mean neutrophil volume, mean monocyte volume, platelet count, and mean platelet volume between groups. Neutrophil counts and NLR were higher in unregulated DM patients with complications than in the regulated DM group. A positive correlation was observed between HbA1c and white blood cell count (r=0.389, P<0.001) and neutrophil count (r=0.361, P<0.001). CONCLUSIONS: In DM patients, neutrophil counts and NLR were related to glycemic control and the presence of complications. Additionally, neutrophil counts showed a positive correlation with HbA1c. Therefore, neutrophil counts and NLR can be used as related markers for diabetic regulation and complications during the follow-up of diabetic patients.

Evaluation of the i-STAT Point-of-Care Analyser

BACKGROUND: Point-of-care testing (POCT) is designed to be used near the site where the clinical care is being delivered. The demand for POCT in the medical field is expanding significantly, given that rapid results can eventually lead to early diagnosis and immediate clinical management of diseases. Therefore, the aim of this study was to evaluate the performance of the i-STAT POC analyser (Abbott Diagnostics, USA) for testing 8 chemical analytes (viz., sodium, potassium, chloride, total carbon dioxide, blood urea nitrogen, creatinine, glucose, and ionised calcium) and 2 hematological analytes (hematocrit [HCT], hemoglobin [Hb]). METHODS: The precision and linearity of the 10 analytes were measured according to Clinical and Laboratory Standards Institute (CLSI) EP15-A3 and EP6-A guidelines. Comparisons with a central laboratory hematology analyser, Coulter LH 780 (Beckman Coulter Inc., USA), and a chemical analyser, UniCel DxC 880i (Beckman Coulter Inc.), were performed using 85 patient samples according to CLSI EP9-A3. RESULTS: The coefficient of variation values for the within-run precision and total precision at 3 levels of all analytes were within 5%, except those for low level creatinine. In the aspect of linearity, the correlation coefficient values of all analytes were over 0.975 in the clinically important concentration range. A very high correlation was observed in glucose, blood urea nitrogen and creatinine (R>0.975), high correlation was observed in sodium, potassium, Hct and Hb (R>0.9), and relatively good correlation was observed in chloride and total carbon dioxide (R>0.7) compared to the central laboratory analysers. CONCLUSIONS: i-STAT showed relatively high precision and linearity, and comparable data to that of routine hematology and chemistry analysers. This device was concluded to have potential for providing faster results and relatively acceptable values to clinicians in need of immediate results.

Overexpression of Efflux Pump in Multiresistant Pseudomonas aeruginosa: How You Will Discover and Treat It? / 감염과화학요법

No abstract available.

Emergence of Acinetobacter pittii Harboring New Delhi Metallo-beta-Lactamase Genes in Daejeon, Korea

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.

Molecular Identification and Amphotericin B Susceptibility Testing of Clinical Isolates of Aspergillus From 11 Hospitals in Korea

BACKGROUND: We investigated the species distribution and amphotericin B (AMB) susceptibility of Korean clinical Aspergillus isolates by using two Etests and the CLSI broth microdilution method. METHODS: A total of 136 Aspergillus isolates obtained from 11 university hospitals were identified by sequencing the internal transcribed spacer (ITS) and beta-tubulin genomic regions. Minimal inhibitory concentrations (MICs) of AMB were determined in Etests using Mueller-Hinton agar (Etest-MH) and RPMI agar (Etest-RPG), and categorical agreement with the CLSI method was assessed by using epidemiological cutoff values. RESULTS: ITS sequencing identified the following six Aspergillus species complexes: Aspergillus fumigatus (42.6% of the isolates), A. niger (23.5%), A. flavus (17.6%), A. terreus (11.0%), A. versicolor (4.4%), and A. ustus (0.7%). Cryptic species identifiable by beta-tubulin sequencing accounted for 25.7% (35/136) of the isolates. Of all 136 isolates, 36 (26.5%) had AMB MICs of > or =2 microg/mL by the CLSI method. The categorical agreement of Etest-RPG with the CLSI method was 98% for the A. fumigatus, A. niger, and A. versicolor complexes, 87% for the A. terreus complex, and 37.5% for the A. flavus complex. That of Etest-MH was < or =75% for the A. niger, A. flavus, A. terreus, and A. versicolor complexes but was higher for the A. fumigatus complex (98.3%). CONCLUSIONS: Aspergillus species other than A. fumigatus constitute about 60% of clinical Aspergillus isolates, and reduced AMB susceptibility is common among clinical isolates of Aspergillus in Korea. Molecular identification and AMB susceptibility testing by Etest-RPG may be useful for characterizing Aspergillus isolates of clinical relevance.

Septic Knee Arthritis Caused by Staphylococcus lugdunensis After Intraarticular Injection Therapy

Staphylococcus lugdunensis is a coagulase-negative staphylococcus. However, it causes various clinically important human infections and behaves similar to Staphylococcus aureus. S. lugdunensis reportedly causes infective endocarditis, skin and soft tissue infection, bone and joint infection, septicemia, endarteritis, urinary tract infection, ocular infection, and peritonitis. There are no reports of septic arthritis by this organism in Korea. We presented a case of septic arthritis due to S. lugdunensis in an elderly patient with diabetes mellitus after an intra-articular injection.

A Case of Pentasomy 21 With Two Isochromosome 21s in Acute Megakaryoblastic Leukemia Associated With Down Syndrome

No abstract available.

Correlation Between Virulence Genotype and Fluoroquinolone Resistance in Carbapenem-Resistant Pseudomonas aeruginosa

BACKGROUND: Pseudomonas aeruginosa is a clinically important pathogen that causes opportunistic infections and nosocomial outbreaks. Recently, the type III secretion system (TTSS) has been shown to play an important role in the virulence of P. aeruginosa. ExoU, in particular, has the greatest impact on disease severity. We examined the relationship among the TTSS effector genotype (exoS and exoU), fluoroquinolone resistance, and target site mutations in 66 carbapenem-resistant P. aeruginosa strains. METHODS: Sixty-six carbapenem-resistant P. aeruginosa strains were collected from patients in a university hospital in Daejeon, Korea, from January 2008 to May 2012. Minimum inhibitory concentrations (MICs) of fluoroquinolones (ciprofloxacin and levofloxacin) were determined by using the agar dilution method. We used PCR and sequencing to determine the TTSS effector genotype and quinolone resistance-determining regions (QRDRs) of the respective target genes gyrA, gyrB, parC, and parE. RESULTS: A higher proportion of exoU+ strains were fluoroquinolone-resistant than exoS+ strains (93.2%, 41/44 vs. 45.0%, 9/20; P< or =0.0001). Additionally, exoU+ strains were more likely to carry combined mutations than exoS+ strains (97.6%, 40/41 vs. 70%, 7/10; P=0.021), and MIC increased as the number of active mutations increased. CONCLUSIONS: The recent overuse of fluoroquinolone has led to both increased resistance and enhanced virulence of carbapenem-resistant P. aeruginosa. These data indicate a specific relationship among exoU genotype, fluoroquinolone resistance, and resistance-conferring mutations.

Epidemiological Characterizations of Class 1 Integrons from Multidrug-Resistant Acinetobacter Isolates in Daejeon, Korea

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.

Vertebral Osteomyelitis caused by Burkholderia cepacia in an Immunocompetent Elderly Patient After Acupuncture

Burkholderia cepacia is an important nosocomial pathogen in hospitalized patients, particularly those with prior antimicrobial therapy. B. cepacia causes various clinically significant infections such as bacteremia, pneumonia, and urinary tract and surgical site infections. However, osteomyelitis caused by B. cepacia is very rare. We present a case of B. cepacia vertebral osteomyelitis with review of the literature.