Abstract: We investigated an outbreak caused by carbapenem-resistant Acinetobacter baumannii carrying the bla(OXA-23) gene. A novel insertion sequence (IS), named ISAba10, was found to be inserted into the ISAba1 element preceding the bla(OXA-23) gene in a group of isolates showing higher carbapenem MICs. The presence of ISAba10 was associated with increased OXA-23 expression, likely by providing additional promoter sequences. ISAba10 was also inserted into the carO outer membrane protein gene in most of these isolates.
Abstract: Phaeohyphomycosis is a subcutaneous infection caused by dark pigmented fungi, including fungi of the species Phaeoacremonium, Alternaria, Exophiala, and Pyrenochaeta. In August 2005, a 54-yr-old man who had received a renal transplant 5 yr ago was admitted to our hospital with a subcutaneous mass on the third finger of the right hand; the mass had been present for several months. He had been receiving immunosuppressive agents for several years. He underwent excision of the mass, which was followed by aspiration of the wound for bacterial and fungal cultures. Many fungal hyphae were observed on the histology slide treated with periodic acid-Schiff stain. A few white waxy colonies with a woolly texture grew on the Sabouraud dextrose agar at 30â and changed to dark brown in color. Nucleotide sequencing of internal transcribed spacer regions revealed 100% homology to the Phaeoacremonium aleophilum anamorph and Togninia minima teleomorph (514 bp/514 bp). The patient completely recovered after wide surgical excision. Here, we report the first case of phaeohyphomycosis caused by Phaeoacremonium species in a kidney transplant patient in Korea.
Abstract: Although Corynebacterium amycolatum can cause opportunistic infections, it is commonly considered as contaminant. In this report, we present a case of bacteremia caused by C. amycolatum with a novel mutation in the gyrA gene that confers high-level quinolone resistance to the organism.
Abstract: to investigate the epidemiological traits of carbapenem-non-susceptible Acinetobacter baumannii (CNSAB) and the usefulness of phylogenetic grouping based on partial rpoB gene sequencing in defining the epidemiological traits of CNSAB.
Abstract: Clostridium difficile infection (CDI) has markedly risen and is associated with hypervirulent ribotype 027 outbreaks in North America and Europe since 2003. The aims of this study were to determine the prevalence of ribotype 027 among C. difficile isolates in Korea, to characterize the ribotype 027 isolates, and to determine the clinical severity of CDI in patients infected with these isolates.
Abstract: Increase in multidrug-resistant Acinetobacter poses a serious problem in Korea. In this study, 190 imipenem (IPM)-nonsusceptible (NS) Acinetobacter isolates from 12 Korean hospitals in 2007 were used to determine species, prevalence, and antimicrobial susceptibility of OXA carbapenemase- and metallo-β-lactamase (MBL)-producing isolates. bla(OXA)-ââ-like and ISAba1-asssociated bla(OXA)-ââ-like genes were detected in 80% and 12% of 178 IPM-NS Acinetobacter baumannii isolates, respectively. A novel bla(OXA)-âââ was detected in 12 IPM-NS A. baumannii isolates. Twelve out of 14 MBL-producing isolates were non-baumanniiAcinetobacter. A. baumannii isolates with OXA carbapenemase were more often resistant to aminoglycosides, ciprofloxacin, and tigecycline than non-baumannii Acinetobacter isolates with MBL. Identical pulsed- field gel electrophoresis patterns were observed in 89% of A. baumannii isolates with bla(OXA)-ââ-like gene. In conclusion, extremely rapid increase of IPM-NS A. baumannii in previous Korean studies was mainly due to clonal spread of OXA-23-producing A. baumannii isolates. A novel OXA-182 emerged in Korea.
Abstract: Clostridium citroniae is a novel species reclassified
from C. clostridioforme. Clostridium species are obligate
anaerobes and spore-forming gram-positive
rods. However, C. citroniae stains gram negative and
does not consistently produce spores, making it difficult
to identify. We isolated C. citroniae from the
blood and peritoneal fluid of one patient, and from
the blood of another patient, both of whom were undergoing
cancer chemotherapy.
Abstract: We determined the antimicrobial susceptibilities of 255 clinical isolates of anaerobic bacteria collected in 2007 and 2008 at a tertiary-care hospital in South Korea. Piperacillin-tazobactam, cefoxitin, imipenem, and meropenem were highly active beta-lactam agents against most of the isolates tested. The rates of resistance of Bacteroides fragilis group organisms and anaerobic gram-positive cocci to moxifloxacin were 11 to 18% and 0 to 27%, respectively.
Abstract: Pseudomonas fulva has not yet been isolated from humans as a pathogen. Herein, we report the first case of P. fulva bacteremia in a patient hospitalized due to trauma. The species was identified using biochemical and molecular genetic analyses of the 16S rRNA, gyrB, rpoB, and rpoD genes.
Abstract: This study was performed to determine the mechanisms for acquiring carbapenem resistance in six clinical isolates of Acinetobacter baumannii. All isolates showed similar SmaI-macrorestriction patterns with less than 3 band differences by PFGE. The isolates showed a high level resistance (>32 mg/L) to both imipenem and meropenem by Etest. Phe-Arg-beta-naphthylamide lowered the MICs of carbapenems. Real-time PCR experiments showed that expression levels of the adeB gene in the six A. baumannii isolates were 10- to 40-times higher than those of imipenem-susceptible strains. Direct sequencing of PCR products showed that all isolates carried the bla(OXA-23) gene, which was preceded by ISAba1. The bla(OXA-23) probe hybridized with approximately 500-kb I-CeuI chromosomal fragments, but not with a plasmid. These findings suggest that overexpression of the AdeABC efflux pump as well as chromosome-borne OXA-23 may play a role in acquiring carbapenem resistance in our A. baumannii isolates.
Abstract: Background : Mecillinam, an amidinopenicillin antibiotic, has been used to treat urinary tract infections and bacterial
enteritis in many countries. In this study, we evaluated in vitro activity of mecillinam against Enterobacteriaceae
isolates from urine, and Salmonella and Shigella isolates from patients with bacterial gastroenteritis.
Materials and Methods : A total of 308 clinical strains were collected and were comprised of Escherichia coli
(n=109), Klebsiella pneumoniae (n=52), Enterobacter spp. (n=30), Serratia marcescens (n=30) and Proteus
spp. (n=29) isolated from a university hospital in Korea in 2007, and of Salmonella spp. (n=28) and Shigella spp.
(n=30) isolated from Korean diarrheal patients from 2001 to 2006. Antimicrobial susceptibility was tested by
Clinical Laboratory Standard Institute (CLSI) agar dilution method. CLSI breakpoint of mecillinam for E. coli urinary
tract isolates was applied to all other isolates.
Results : In E. coli, rate of susceptibility to ampicillin was 30%, but 99-100% to amikacin and cefotaxime. Most
(96%) of E. coli isolates, including extended-spectrum β-lactamase (ESBL) producers, were susceptible to mecillinam.
All ESBL producers, except for one isolate, were inhibited by â¤4 μg/mL of mecillinam. MIC90 of mecillinam
for K. pneumoniae and Enterobacter spp. was 8 μg/mL and 1 μg/mL, respectively, and the susceptibility rate
was 92% and 97%, respectively. However, MIC90 of mecillinam for S. marcescens isolates was >128 μg/mL and
most of them were resistant to mecillinam. All Salmonella isolates and 27 of 30 Shigella isolates were susceptible
to mecillinam.
Conclusion : Mecillinam was active in vitro against most Enterobacteriaceae, Salmonella, and Shigella isolates
except for S. marcescens. Therefore, mecillinam can be a good alternative agent for treating urinary tract infection
and bacterial gastroenteritis.
Abstract: Background : In Korea, a platelet transfusion dose (TD) of 8 units of platelet concentrates (PC) is
usually used. To minimize the shortage of blood products and transfusion-related adverse reactions,
the TD has been changed from 8 to 6 units in 2006 in our hospital. Here, we analyzed the dose reduction
effect on patientsâ platelet counts and transfusion frequency.
Methods : We compared the amount of issued PC, platelet counts before and after transfusion,
post-transfusion platelet increments, and transfusion frequencies in patients who were transfused
with 8 PC in 2006 and 6 PC in 2008.
Results : Despite an increase in the number of admitted patients by 20% in 2008 with a disease
distribution similar to that in 2006, the number of issued PC in 2008 was decreased by 26.6% compared
to that in 2006. In 2008, post-transfusion platelet counts, pre-transfusion platelet counts in
patients transfused with 320 mL whole blood-derived PC, and platelet increments in patients transfused
with 400 mL whole blood-derived PC were significantly decreased. However, the mean transfusion
frequency per one month was not significantly different, 4.3 times in 2006 and 4.7 in 2008.
Conclusions : By implementing a policy of platelet TD restriction, the amount of total issued PC
was markedly decreased. Although post-transfusion platelet counts were decreased, the transfusion
frequency in a month was not significantly increased. The restriction of platelet TD was helpful
for increasing physiciansâ recognition of blood shortage while achieving similar transfusion effects.
We conclude that 6 units of PC would be a better guideline for the platelet TD.
Abstract: Background : Anaerobic bacteria can cause various infections, and their incidence may differ greatly, depending
on the country or hospital. We investigated recent trends in anaerobe isolation and clinical characteristics of
anaerobic bacteremia in one hospital in Korea to facilitate diagnosis and treatment of anaerobic infections.
Materials and Methods : Anaerobic bacteria isolated from blood, body fluids and abscess specimens at a university
hospital in Korea during 2007 and 2008 were analyzed. The medical records of 82 anaerobic bacteremia patients
were reviewed. A retrospective cohort study was conducted to determine the risk factors for in-hospital mortality
of patients with anaerobic bacteremia.
Results : A total of 289 non-duplicated anaerobic isolates were recovered from blood, body fluids and abscess
specimens. Bacteroides fragilis (73 isolates, 25.3%) was the most common organism followed by Clostridium
perfringens (22 isolates, 7.6%), Peptoniphilus asaccharolyticus (21 isolates, 7.3%) and Anaerococcus prevotii (19
isolates, 6.6%). Eighty-four isolates were recovered from blood specimens, among which B. fragilis (24 isolates)
and C. perfringens (21 isolates) were the most frequently isolated organisms. Among the 196 underlying diseases
of anaerobic bacteremia patients, neoplastic, infectious, and gastrointestinal diseases accounted for 54 (27.6%),
46 (23.5%), and 41 (20.9%) cases, respectively. The alimentary tract was the most common suspected portal of
entry. The in-hospital mortality rate of anaerobic bacteremia patients was 34.2%, and neutropenia at the time of
blood culture was the only statistically significant factor associated with mortality in this study. Anaerobes were
isolated in 1.4% of all positive blood cultures.
Conclusions : B. fragilis and C. perfringens are expected to be commonly isolated from clinical specimens. Despite
its low prevalence, anaerobic bacteremia displays a significant in-hospital mortality rate. Ongoing investigations
into anaerobic bacteremia are necessary because of ambiguous risk factors for mortality.
Abstract: BACKGROUND: We investigated the characteristics of the mononuclear cells remaining in the leukoreduction system (LRS) chambers of Trima Accel in comparison with those of standard buffy coat cells, and evaluated their potential for differentiation into dendritic cells. METHODS: Twenty-six LRS chambers of Trima Accel were collected after platelet pheresis from healthy adults. Flow cytometric analysis for T, B, NK, and CD14+ cells was performed and the number of CD34+ cells was counted. Differentiation and maturation into dendritic cells were induced using CD14+ cells seperated via Magnetic cell sorting (MACS) Seperation (Miltenyi Biotec Inc., USA). RESULTS: Total white blood cell (WBC) count in LRS chambers was 10.8 x 10(8) (range 7.7-18.0 x 10(8)). The median values (range) of proportions of each cells were CD4+ T cell 29.6% (18.7-37.6), CD8+ T cell 27.7% (19.2-40.0), B cell 5.5% (2.2-12.1), NK cell 15.7% (13.7-19.9), and CD14+ cells 12.4% (8.6-32.3) respectively. Although total WBC count was significantly higher in the buffy coat (whole blood of 400 mL) than the LRS chambers, the numbers of lymphocytes and monocytes were not statistically different. The numbers of B cells and CD4+ cells were significantly higher in the buffy coat than the LRS chambers (P<0.05). The median value (range) of CD34+ cells obtained from the LRS chambers was 0.9 x 10(6) (0.2-2.6 x 10(6)). After 7 days of cytokine-supplemented culture, the CD14+ cells were successfully differentiated into dendritic cells. CONCLUSIONS: The mononuclear cells in LRS chambers of Trima Accel are an excellent alternative source of viable and functional human blood cells, which can be used for research purposes.
Abstract: This study was to determine the prevalence and characteristics of CTX-M-type extended-spectrum beta-lactamases (ESBLs) in nonduplicate Escherichia coli (n=760) and Klebsiella pneumoniae (n=379) bloodstream isolates collected during January 2005 to October 2007 at a university hospital (2000 beds) in Seoul, Korea. Antimicrobial susceptibilities were determined by disk diffusion and agar dilution methods. The double-disk synergy test detected ESBLs in 8.7% (66/760) of E. coli and 11.3% (43/379) of K. pneumoniae isolates. Polymerase chain reaction detected bla(CTX-M) in 60/66 (90.9%) E. coli and 9/43 (20.9%) K. pneumoniae isolates with the ESBL phenotype. CTX-M-14 was the most common type of CTX-M ESBLs in both E. coli (n=32) and K. pneumoniae (n=6). CTX-M-15 was the 2nd most common type of CTX-M ESBLs in E. coli (n=22), but it was not detected in K. pneumoniae. In addition, CTX-M-24 (n=2), CTX-M-65 (n=2), CTX-M-27 (n=1), and CTX-M-32 (n=1) were detected for the 1st time in Korea.
Abstract: The patient was a 70-year-old woman with hypertension and end stage renal disease, and she presented with
left wrist pain due to falling a day before admission. On admission, laboratory testing revealed a hemoglobin
level of 6.7 g/dL, and a physician ordered 2 units of packed RBCs. She had never received a RBC transfusion
in the past. The ABO grouping showed a discrepancy between the cell type AB and serum type O, and the
irregular antibody screening was negative. Crossmatchings with group AB and group O RBCs were
incompatible. Anti-I, which is a cold antibody, was inferred because the degree of agglutination was decreased
after warming. However, crossmatching with group O RBCs, which are the universal donor blood, was positive
and the anti-IH was considered to be the specificity of the irregular antibody. The patient's serum did not
react with group O cord (i) blood cells and anti-I was then considered. The genotype of this patient was AB,
and it was inferred that the ABO discrepancy was due to anti-IH.
Abstract: BACKGROUND: Cinical and Laboratory Standards Institute (CLSI) recommends the use of cefoxitin disks instead of long-used oxacillin disks for screening methicillin-resistant isolates of staphylococci. The frequency of discrepant results and accuracy of the tests were evaluated by detecting mecA gene. METHODS: A total of 3,123 Stapylococci isolates from patients in Severance Hospital were tested during September 2005 to August 2006 by the CLSI-recommended test using both cefoxitin and oxacillin disks. The mecA gene was detected by PCR and the oxacillin minimum inhibitory concentration (MIC) was determined by using agar dilution method for the isolates with discrepant tests. RESULTS: Among 1,915 S. aureus islolates tested, one isolate was resistant to oxacillin disk but susceptible to cefoxitin disk; the isolate did not have mecA gene. Another isolate susceptible to oxacillin but resistant to cefoxitin had mecA gene. Among 1,208 coagulase-negative staphylococcal isolates, 15 isolates were resistant to oxacillin disk but susceptible to cefoxitin disk; the isolates did not have mecA genes. Two isolates susceptible to oxacillin disk but resistant to cefoxitin disk had mecA genes. Among the 16 Staphylococcus isolates that did not have mecA gene, 15 isolates had the oxacillin MICs of </= 2 microg/mL and were considered as methicillin-susceptible, while 1 isolate with the MIC of 4 microg/mL was considered as methicillin-resistant. CONCLUSIONS: Overall, 1.9% of staphylococcal isolates showed discrepant results when the screening tests were performed by using oxacillin and cefoxitin disks. None of the isolates resistant to oxacillin disk but susceptible to cefoxitin disk had mecA gene. In conclusion, the cefoxitin disk test is more reliable than oxacillin disk test in screening methicillin-resistant staphylococcal isolates.
Abstract: Heparin-induced thrombocytopenia (HIT) is usually caused by anti-platelet factor 4 (PF4)/heparin
antibodies, leading to intravascular platelet activation. Circulating anti-PF4/heaprin antibody (IgG, IgA
and IgM) was detected by ELISA (Asserachrom HPIA, Diagnostia Stago, Asnieres, France) in a 61-yearold
man with coronary artery disease and dyspnea on exercise. He had undergone a coronoary angiography
using 2,000 unit of heparin before a procedure. On admission, laboratory testing revealed a platelet count
of 296Ã109/L and aPTT (activated partial thromboplastin time) of 38.1 sec. The fall in the platelet count
was progressive, resulting in 42% and 53% of platelet counts on the 6th and 12th days after intravenous
heparin administration, respectively. He was discharged after coronary artery bypass graft. On discharge,
platelet count was normalized to be 212Ã109/L. On the 7th day after dischage, anti-PF4/heaprin antibody
was detected by ELISA (Asserachrom HPIA, Diagnostia Stago, Asnieres, France).
Abstract: Background: High dose chemotherapy followed by autologous peripheral blood stem cell transplantation
(PBSCT) has become standard therapy for high-risk neuroblastoma patients. We performed a retrospective
analysis to assess the characteristics of peripheral blood stem cell harvest (PBSCH) and PBSCT and its clinical
outcome.
Methods: We reviewed 17 cases of patients with high-risk neuroblastoma that underwent PBSCH and/or high
dose chemotherapy followed by PBSCT.
Results: Sixteen patients had stage IV neuroblastoma and one patient had a stage III neuroblastoma with MYCN
amplification. The median age of the 17 patients was 43 months (range 22â¼114 months) and the median body
weight was 15 kg (range 10â¼24 kg). After induction chemotherapy using a modified N7 protocol, 34 PBSCHs
(1.5 leukapheresis per PBSCH) were performed. A statistically significant correlation was found between the
pre-leukapheresis CD34+ cell count and the total number CD34+ cells of the harvested products (Pï¼0.0001).
Tyrosine hydroxylase mRNA was not detected by RT-PCR in all of the leukapheresis products. High dose
chemotherapy followed by PBSCT was performed in 24 cases. The mean infused CD34+ cell dose was
4.01Ã106/kg and WBC and platelet engraftment was performed on day 12.0 and 21.5, respectively. Eleven
patients died, and six patients are surviving 11 to 68 months after PBSCT (median survival time, 35 months).
Conclusion: In this single institution study, treatment with high dose chemotherapy and PBSCT was performed successfully for children with high-risk neuroblastoma.
Abstract: Background: The domestic quantity of blood components consumed has been decreasing since 2002, but the
rate of a single unit RBC transfusion (SUT) has been on the increase. In the past, a SUT was regarded as
an uncesssary procedure, but currently is considered as an effective method to maintain a minimal hemoglobin
concentration for physiological needs. We investigated the actual conditions of a SUT.
Methods: We analyzed 800 cases of SUTs performed at a tertiary care university hospital between March 2006
March and February 2007. The subjects of the study were divided into a surgical group (n=561) and medical
group (n=239) for the purpose of RBC unit usage and were analyzed by groups and ordering departments,
with an analysis of the pre and post-transfusion hemoglobin concentration and hematocrit values. The distribution
according to the pre and post-transfusion hemoglobin ranges were calculated.
Results: The mean hemoglobin concentration increment of the surgical group was significantly lower than that
of the medical group (Pï¼0.0001) and the mean pre and post-transfusion hemoglobin concentrations of the
medical group were lower than that of the surgical group (Pï¼0.0001). Approximately 26% cases of the SUTs
performed in the surgical group were appropriate, based on a post-transfusion hemoglobin concentration below
10 g/dL. In the medical group, about 75% of the SUTs were appropriate based on a pre-transfusion hemoglobin
concentration below 9 g/dL.
Conclusion: Most transfusions are decided based on various clinical situations and opinions of the clinicians.
Therefore, continuous evaluation of the appropriateness of transfusion is necessary. In our study, the appropriateness
of a SUT was estimated indirectly based on the pre and post-transfusion hemoglobin concentration.
Consequently, policies and strategies for performing asingle unit RBC transfusion are required.
