Sae Am Song

Comprehensive analysis of blood culture performed at nine university hospitals in Korea.

Background Optimal blood culture performance is critical for successful diagnosis and treatment of sepsis. To understand the status of blood culture, we investigated several aspects of the procedure at 9 university hospitals. Methods The process of ordering blood culture sets and sampling volume for adults and children was investigated from January 2010 to April 2010, while the positive rate of detection and growth of skin contaminants were compared in 2009. Microbial growth in aerobic and anaerobic bottles was investigated prospectively. Results A majority of the hospitals used 2 sets of bottles for adults and 1 bottle for children. The average blood volume in each set was 7.7 mL for adults and 2.1 mL for children. The positive rate of microorganisms was 8.0%, and the isolation rate of the normal flora of the skin was 2.1%. Bacterial growth rates in aerobic and anaerobic bottles only were 31.8% and 24.5% respectively. Conclusions Ordering blood culture sets and sampling volumes did not comply with CLSI guidelines. However, the rate of positive cultures and skin contamination rates were acceptable. Anaerobic bottles are useful in enhancing the yield of microorganisms.

Nationwide Survey of Blood Culture Performance Regarding Skin Disinfection, Blood Collection and Laboratory Procedures

Background: Although many laboratories use automated blood culture systems, adequate skin disinfection and optimal blood volume are still critical for successful culture. The authors undertook a nationwide survey to understand the current situation and problems of blood culture in Korea. Methods: A survey of blood culture was performed in March and April 2010, including disinfectants, blood collection intervals, and recommended blood volumes. The laboratory physicians described the storage condition of culture bottles before delivery to the equipment. For quality control, the positive rate and skin contamination rate were studied. Results: Replies to the survey were collected from 74 Korean hospitals. Povidone iodine after either isopropyl alcohol or ethanol application was the most common means of skin disinfection. Sampling of a second set of cultures was performed simultaneously in 38% of hospitals and after a 30-min interval in 50%. The recommended blood volume was 10 mL in most cases (69%), but was 20 mL in 24% of cases. The bottles were stored at 37C before installation in 23% of cases and at room temperature in 16%, whereas 57% were placed directly in the equipment during the night shift. Positive rates ranged 8-10% in 32% of hospitals, 5-8% in 23%, and 3% in 13%. Conclusion: Skin disinfection methods were rather variable. Sampling interval, blood volume, and storage of bottles should be standardized. More than 10% of the hospitals require quality improvement in terms of positive rate and skin contamination rates. (Korean J Clin Microbiol 2011;14:91-96)

Evaluation of DNA extraction methods and their clinical application for direct detection of causative bacteria in continuous ambulatory peritoneal dialysis culture fluids from patients with peritonitis by using broad-range PCR.

Background The aims of this study were to compare several DNA extraction methods and 16S rDNA primers and to evaluate the clinical utility of broad-range PCR in continuous ambulatory peritoneal dialysis (CAPD) culture fluids. Methods Six type strains were used as model organisms in dilutions from 108 to 100 colony-forming units (CFU)/mL for the evaluation of 5 DNA extraction methods and 5 PCR primer pairs. Broad-range PCR was applied to 100 CAPD culture fluids, and the results were compared with conventional culture results. Results There were some differences between the various DNA extraction methods and primer sets with regard to the detection limits. The InstaGene Matrix (Bio-Rad Laboratories, USA) and Exgene Clinic SV kits (GeneAll Biotechnology Co. Ltd, Korea) seem to have higher sensitivities than the others. The results of broad-range PCR were concordant with the results from culture in 97% of all cases (97/100). Two culture-positive cases that were broad-range PCR-negative were identified as Candida albicans, and 1 PCR-positive but culture-negative sample was identified as Bacillus circulans by sequencing. Two samples among 54 broad-range PCR-positive products could not be sequenced. Conclusions There were differences in the analytical sensitivity of various DNA extraction methods and primers for broad-range PCR. The broad-range PCR assay can be used to detect bacterial pathogens in CAPD culture fluid as a supplement to culture methods.

Serial changes in serum procalcitonin, interleukin 6, and C-reactive protein levels according to non-specific surgical stimulation.

Abstract Background: The aim of this study is to investigate useful perioperative monitoring markers by comparing serial levels of serum procalcitonin (PCT), interleukin 6 (IL-6), and C-reactive protein (CRP) in routine surgical circumstances. Methods: In 285 surgeries of 277 patients, blood samples were obtained serially, at least three times per patient: within 48 h before surgery, 0–6 h after surgery (post-OP1), >6–28 h after surgery (post-OP2), and/or later (post-OP3). PCT, IL-6, and CRP were measured. Their demographic, operative, laboratory, and clinical data were collected retrospectively. Results: The systemic inflammatory response syndrome (SIRS) (n=39) and sepsis (n=11) groups showed higher post-operative values than the non-SIRS group (n=233). Their maximum significant median levels were 8.96 vs. 0.21 μg/L for post-OP2 PCT, 743.1 vs. 85.8 ng/L for post-OP1 IL-6, and 103.4 vs. 49.0 mg/L for post-OP2 CRP. Among non-SIRS patients, 12 patients developed undesirable post-operative events, including secondary surgery and death. The highest area under receiver operator characteristic curves was 0.92 at post-OP1 PCT (cut-off, 0.1 μg/L; sensitivity, 91.7%; specificity, 78.7%), and the next highest was 0.84 at post-OP1 IL-6 (cut-off, 359 ng/L; sensitivity, 66.7%; specificity, 91.9%). All biomarkers were increased by non-specific surgical stimuli; however, post-OP1/post-OP2 PCT were <1.0 μg/L (90th percentile) except major abdominal surgeries. Conclusions: Post-OP1 PCT measurement may be useful as a post-operative monitoring marker for the following reasons: pre-operative values less than the cut-off regardless of pre-operative state (age, malignancy, and American Society of Anesthesiologists class); minimal influence from surgical stimulus; and prediction of post-operative undesirable events.

Two childhood cases of acute leukemia with t(16;21)(p11.2;q22): second case report of infantile acute lymphoblastic leukemia with unusual type of FUS-ERG chimeric transcript

We report two childhood cases of acute leukemia with t(16;21)(p11.2;q22) and FUS-ERG rearrangements. Patient 1 (14 years old) was initially diagnosed with acute myeloid leukemia. Chromosome study showed a t(16;21)(p11.2;q22) clone in more than one third of the cells analyzed, and further investigation with reverse-transcriptase polymerase chain reaction, cloning, and sequencing confirmed FUS-ERG rearrangement (type B). Patient 2 (8 months old) was diagnosed with acute lymphoblastic leukemia (ALL) on the basis of bone marrow morphology and immunophenotyping. Chromosome study revealed a 45,XY,-16,der(21)t(16;21)(p11.2;q22) in 50% of the cells analyzed. Further studies for the detection of a FUS-ERG chimeric transcript were conducted, and an unusual type of FUS-ERG rearrangement was discovered, which has been reported in only three patients including a 1-year-old infant with ALL. Although more clinical studies are necessary, we believe that a possible association between ALL and a specific type of FUS-ERG fusion transcript might be considered, especially in childhood cases with t(16;21).

Misidentification of Candida guilliermondii as C. famata among strains isolated from blood cultures by the VITEK 2 system.

Introduction. The aim of this study was to differentiate between Candida famata and Candida guilliermondii correctly by using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and gene sequencing. Methods. Twenty-eight Candida strains from blood cultures that had been identified as C. famata (N = 25), C. famata/C. guilliermondii (N = 2), and C. guilliermondii (N = 1) by the VITEK 2 system using the YST ID card were included. We identified these strains by MALDI-TOF MS and gene sequencing using the 28S rRNA and ITS genes and compared the results with those obtained by the VITEK 2 system. Results. All 28 isolates were finally identified as C. guilliermondii. Sequencing analysis of the 28S rRNA gene showed 99.80%–100% similarity with C. guilliermondii for all 28 strains. The ITS gene sequencing of the strains showed 98.34%–100% homology with C. guilliermondii. By MALDI-TOF, we could correctly identify 21 (75%) of 28 C. guilliermondii isolates. Conclusion. We should suspect misidentification when C. famata is reported by the VITEK 2 system, and we always should keep in mind the possibility of misidentification of any organism when an uncommon species is reported.

Serotype Distribution and Antimicrobial Resistance of Streptococcus pneumoniae Isolates Causing Invasive and Noninvasive Pneumococcal Diseases in Korea from 2008 to 2014

Introduction. Streptococcus pneumoniae is an important pathogen with high morbidity and mortality rates. The aim of this study was to evaluate the distribution of common serotypes and antimicrobial susceptibility of S. pneumoniae in Korea. Methods. A total of 378 pneumococcal isolates were collected from 2008 through 2014. We analyzed the serotype and antimicrobial susceptibility for both invasive and noninvasive isolates. Results. Over the 7 years, 3 (13.5%), 35 (10.8%), 19A (9.0%), 19F (6.6%), 6A (6.1%), and 34 (5.6%) were common serotypes/serogroups. The vaccine coverage rates of PCV7, PCV10, PCV13, and PPSV23 were 21.4%, 23.3%, 51.9%, and 62.4% in all periods. The proportions of serotypes 19A and 19F decreased and nonvaccine serotypes increased between 2008 and 2010 and 2011 and 2014. Of 378 S. pneumoniae isolates, 131 (34.7%) were multidrug resistant (MDR) and serotypes 19A and 19F were predominant. The resistance rate to levofloxacin was significantly increased (7.2%). Conclusion. We found changes of pneumococcal serotype and antimicrobial susceptibility during the 7 years after introduction of the first pneumococcal vaccine. It is important to continuously monitor pneumococcal serotypes and their susceptibilities.

MALDI-TOF MS is more accurate than VITEK II ANC card and API Rapid ID 32 A system for the identification of Clostridium species

All 50 Clostridium difficile strains were definitely identified by Vitek2 system, Rapid ID 32A system, and MALDI-TOF. For 18 non-difficile Clostridium strains, the identification results were correct in 2, 0, and 17 strains by Vitek2, Rapid ID 32A, and MALDI-TOF, respectively [corrected].

Acute myeloid leukemia associated with t(10;17)(p13-15;q12-21) and phagocytic activity by leukemic blasts: a clinical study and review of the literature

Translocation (10;17)(p13-15;q12-21) in acute leukemia is rarely reported in the literature. Here, we present both a novel t(10;17) case study and a review of relevant literature on t(10;17) in acute leukemia (10 cases). In summary, we came to the following preliminary conclusions: t(10;17) is associated with poorly differentiated acute leukemia subtype [90%; eight cases of acute myeloid leukemia (AML M0, M1) and one case of acute undifferentiated leukemia], phagocytic activity by blasts occurs (30%), and the survival time was short in three of the seven t(10;17) cases for whom follow-up data were available (median, 8 months). More clinical studies concerning the prognosis, treatment response, and survival of patients with t(10;17) are necessary.

Clinical Usefulness of Routine Use of Anaerobic Blood Culture Bottle

Background: Blood culture for diagnosis of bacter- emia and fungemia comprises aerobic and anaerobic cultures. The clinical utility of routine anaerobic blood culture has been questioned for a long time and was evaluated in this study. Methods: A total of 9,028 positive blood cultures were collected...