Amplification Failure by the Cepheid Xpert Xpress SARS-CoV-2 Assay due to a Single-Nucleotide Variant of the N Gene in the Omicron Variant

BACKGROUND

Rapid identification of SARS-CoV-2 infection using molecular testing has played an important role in preventing the spread of COVID-19. However, the failure of SARS-CoV-2 N gene amplification in the Cepheid Xpert SARS-CoV-2 assay could lead to the failed detection of infections, possibly leading to spread. In this study, we examined N gene amplification failure due to a single-nucleotide variant (SNV) in the N2 region of the gene.

METHODS

Xpert assay results obtained at our hospital since March 2021 were retrospectively reviewed and samples with strong E gene and failed N gene amplification were selected. Whole-genome sequencing was performed using the Illumina platform. Lineage analyses were conducted and the N2 target region of the US CDC 2019-nCoV real-time PCR primer sequence, used in PCR assays of SARS-CoV-2 infection, was compared with the reference SARS-COV-2 sequence (Wuhan-Hu-1, NC_045512.2).

RESULTS

The two samples eligible for this study were classified as BA.5.2 (22B, Omicron) and included two synony-mous SNVs, C29197T and C29200T, respectively. Both variants resulted in synonymous mutation of the N gene encoding alanine. The distribution of variants varied across different countries.

CONCLUSIONS

Clinical laboratories performing molecular tests targeting the N gene of SARS-CoV-2 should consider the probability of N gene amplification failure when reporting the test results.

Clinical and Microbiological Characteristics of Chryseobacterium indologenes Bacteremia: A 20-Year Experience in a Single University Hospital

BACKGROUND

Chryseobacterium indologenes is ubiquitous in nature and rarely causes infections. However, the clinical impact of C. indologenes has increased in recent years, especially in immunocompromised patients, and has resulted in high mortality rates. We aimed to investigate the clinical and microbiological characteristics of C. indologenes bacteremia.

MATERIALS AND METHODS

We retrospectively reviewed medical records of a 642-bed university-affiliated hospital in Korea, dating from January 2001 to December 2020, to investigate C. indologenes bacteremia.

RESULTS

A total of 22 C. indologenes isolates were identified from blood culture records. All patients were hospitalized at the time of bacteremia, and the most common manifestation was primary bacteremia. A sizable majority of the patients (83.3%) had underlying diseases, and all patients received intensive care unit care during their admission. The 14-day and 28-day mortality rates were 8.3% and 16.7%, respectively. Importantly, all C. indologenes isolates were 100% susceptible to trimethoprim-sulfamethoxazole.

CONCLUSION

In our study, most of the infections were hospital-acquired, and the susceptibility pattern of the C. indologenes isolates showed multidrug resistance. However, trimethoprim-sulfamethoxazole is a potentially useful antibiotic for C. indologenes bacteremia treatment. More attention is required to identify C. indologenes as one of the most important nosocomial bacteria with detrimental effects in immunocompromised patients.

A case of bacterial keratitis caused by multi-drug-resistant Shewanella algae without marine exposure

Shewanella are Gram-negative rods and marine pathogens. Here, we report a case of bacterial keratitis caused by Shewanella algae without marine exposure. A 66-year-old man with suspected pneumonia was sent to the emergency department from a nursing hospital. He had been in there for 2 years in a vegetative state and could not close his eyes voluntarily. Neither the patient nor his family had experienced any marine exposure. Keratitis was suspected in his right eye. Gram-negative rods grew from swab culture and identified as S. algae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing. The patient was treated with topical tobramycin, moxifloxacin and ofloxacin as well as steroids for 14 days, and the keratitis improved. S. algae is a rare human pathogen, and most human infections involve marine exposure. This is the second report of bacterial keratitis caused by S. algae worldwide and the first in Asia.

Preanalytical Errors in the Central Laboratory of a University Hospital Based on the Analysis of Year-Round Data

BACKGROUND

Preanalytical errors cause a decrease in the accuracy of clinical laboratory results. We analyzed preanalytical errors (preAEs) made in the clinical laboratory of a university hospital.

METHODS

All samples received in a centralized laboratory from January 1, to December 31, 2018, were analyzed retrospectively. The categories of preAEs were improper request, incorrect labeling, improper collection/transport, inadequate sample volume, inappropriate container, hemolysis, and sample clotting. The rates of preAEs in these categories were calculated according to sample type, laboratory subunit, department, sampling place, sampling time, and patient age.

RESULTS

Of 1,082,014 samples received and analyzed by the laboratory, 6,848 (0.63%) were classified as having preAEs. The most frequent categories of preAE were hemolysis (44.6%), sample clotting (30.8%), and inadequate volume (16.7%). The most frequent preAE category for whole-blood and serum/plasma was clotting and hemolysis, respectively. The most frequent preAE category in the blood bank, clinical chemistry, immunology, and test referral service laboratory subunits was hemolysis, in the hematology subunit it was sample clotting, and in the microbiology and urinalysis subunits it was inadequate sample volume. Surgical departments had a higher rate of preAEs than did non-surgical departments (p < 0.0001). Samples drawn in the sampling room showed the lowest frequencies of preAEs (0.01%). Samples drawn on general wards from 5 pm to 5 am, when duty nurses perform sampling, showed a preAE rate of 2.80%. The rate of preAEs increased with patient age.

CONCLUSIONS

This analysis of preAEs is the most comprehensive to date. Our findings will promote the provision of high-quality laboratory services to clinicians and their patients.

Effects of the new diagnosis-related group-based payment system and the increased incentive policy rates on the utilization rate of diagnostic laboratory test in Korea

A new diagnosis-related group (DRG) based payment system has been implemented in most public hospitals in Korea. We investigated the effects of the new DRG system and its incentive policy on the utilization rate of diagnostic laboratory tests. Three groups were categorized; 36 hospitals under the new DRG system (participant group), 72 hospitals (control-1) matching with 36 participants according to the number of beds, and 42 tertiary hospitals (control-2). The patients of acute myocardial infarction, cerebral infarction, type 2 diabetes mellitus, and gonarthrosis receiving total arthroplasty were included. We analyzed the mean length of stay and the number of diagnostic laboratory tests conducted during hospitalization of the three groups according to the new DRG system and the incentive policy rates under the new DRG system. Before participating in the new DRG system, the number of diagnostic laboratory tests in the participant group was less than that in the two control groups for all four diseases. However, although the participant group’s length of stay decreased under the new DRG system, the number of diagnostic laboratory tests increased as the maximum incentive policy rate increased. The increment of the number of diagnostic laboratory tests was prominent in the period of a maximum of 35% incentive policy rates. Finally, the number of diagnostic laboratory tests of the participant group was similar to or exceeded that of the control-2 group. The new DRG system’s incentive policy rates played a driving force on the increased utilization rate of the diagnostic laboratory test. For preparing in advance for the change in incentive policy rates, monitoring and guidelines for the utilization of diagnostic laboratory tests are necessary.

First Case of Intracranial Mycotic Aneurysm Caused by Prevotella intermedia Associated with Chronic Sinusitis in a Korean Adult

Intracranial infection caused by anaerobic bacteria is rare, and it is difficult to identify absolute anaerobes in the clinical laboratory, especially when the bacterial load is low. Here, we report the first case of intracranial mycotic aneurysm caused by Prevotella intermedia associated with chronic sinusitis and successful identification of the bacteria by 16S rRNA sequencing from bacterial growth in broth only.

Real-time display of laboratory testing status improves satisfaction levels in an emergency department: A pilot study

Background

Clinicians need to know timelines of requested laboratory tests to provide effective patient management. We developed a real‐time laboratory progress checking system and measured its effectiveness using appropriate indicators in an emergency room setting.

Methods

In our original in‐house health information system display, blank spaces, which were generated for test results when tests were ordered, remained empty until the final results reported. We upgraded the laboratory reporting system to show real‐time testing information. The stages included requests for test, label printing, sampling, laboratory receipts, performance of tests, verification of results, and interpretation of results and final report by laboratory physician. To assess the usefulness of the function, we measured the emergency department healthcare workers' satisfaction and compared the number of phone calls about test status before and after implementation.

Results

After the system upgrade, the healthcare workers' understanding of the testing process increased significantly as follows. More clinicians could estimate the time of final test results through the real‐time testing status information (61.9% and 85.7%, P = .002), and respondents reported that the upgraded system was more convenient than the original system (41.3% and 22.2%, respectively, P = .022). The number of phone calls about the test status decreased after implementation of the upgrade; however, the difference was not statistically significant (before, 0.13% [63 calls/48 637 tests] and after, 0.09% [42/46 666]; P = .066).

Conclusions

The real‐time display of laboratory testing status increased understanding of testing process among healthcare workers in emergency room, which ultimately may increase the usefulness and efficiency of the laboratory service use.

Getting patient blood management Pillar 1 right in the Asia-Pacific: a call for action

Preoperative anaemia is common in the Asia-Pacific. Iron deficiency anaemia (IDA) is a risk factor that can be addressed under patient blood management (PBM) Pillar 1, leading to reduced morbidity and mortality. We examined PBM implementation under four different healthcare systems, identified challenges and proposed several measures: (a) Test for anaemia once patients are scheduled for surgery. (b) Inform patients about risks of preoperative anaemia and benefits of treatment. (c) Treat IDA and replenish iron stores before surgery, using intravenous iron when oral treatment is ineffective, not tolerated or when rapid iron replenishment is needed; transfusion should not be the default management. (d) Harness support from multiple medical disciplines and relevant bodies to promote PBM implementation. (e) Demonstrate better outcomes and cost savings from reduced mortality and morbidity. Although PBM implementation may seem complex and daunting, it is feasible to start small. Implementing PBM Pillar 1, particularly in preoperative patients, is a sensible first step regardless of the healthcare setting.

Outbreak of Burkholderia cepacia pseudobacteraemia caused by intrinsically contaminated commercial 0.5% chlorhexidine solution in neonatal intensive care units

BACKGROUND

Burkholderia cepacia is intrinsically resistant to certain antiseptics. The authors noted a sudden increase in the frequency of isolation of B. cepacia from blood cultures in a neonatal intensive care unit (NICU) of a university-affiliated hospital.

AIM

To identify the source and intervene in the ongoing infections.

METHODS

The cases were defined as patients with positive blood cultures for B. cepacia in an NICU between November 2014 and January 2015. Medical records were reviewed and NICU healthcare workers were interviewed. Samples of suspected antiseptics, blood culture bottles, cotton balls, gauze and a needle used in the NICU were analysed microbiologically.

FINDINGS

During the outbreak period, B. cepacia was identified in 25 blood cultures obtained from 21 patients. The clinical features of the patients were suggestive of pseudobacteraemia. Regarding environmental samples, B. cepacia was cultured from 0.5% chlorhexidine gluconate (CHG) solution products that had been used as a skin antiseptic during blood drawing in the NICU. The clinical B. cepacia isolate and two strains obtained from 0.5% CHG exhibited identical pulsed-field gel electrophoresis patterns. After the CHG products were withdrawn, the outbreak was resolved.

CONCLUSIONS

The pseudobacteraemia cases were caused by contaminated 0.5% CHG produced by a single manufacturer. Stricter government regulation is needed to prevent contamination of disinfectants during manufacturing. In addition, microbial contamination of antiseptics and disinfectants should be suspected when a B. cepacia outbreak occurs in hospitalized patients.

Serum BDNF levels in relation to illness severity, suicide attempts, and central serotonin activity in patients with major depressive disorder: a pilot study

The aim of this study was to test the hypothesis that serum levels of brain-derived neurotrophic factor (BDNF) are correlated with the loudness dependence of auditory evoked potentials (LDAEP). The question of whether there is a difference in BDNF levels between depressive patients according to their illness severity, history of suicide attempts, and central serotonin activity was also addressed. A sample of 51 patients who met the criteria for major depressive disorder following diagnosis using axis I of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders – text revision comprised the study subjects. The patients were stratified into two subgroups based on their illness severity, history of suicide attempts, and their LDAEP values. The LDAEP was evaluated by measuring the auditory event-related potentials, and serum BDNF was measured using blood sampling before beginning medication with serotonergic agents. There was no difference in serum BDNF levels between the two patient subgroups. The subgroup with moderate-to-severe depression (n = 16) was reanalyzed after stratifying it into two subgroups according to LDAEP and BDNF values (dichotomized at the medians into low and high). The high-LDAEP subgroup had higher serum BDNF levels and total Barratt Impulsiveness Scale score than the low-LDAEP subgroup (p = 0.03 and 0.036, respectively). Serum BDNF levels were positively correlated with LDAEP and total Beck Hopelessness Scale (BHS) score (r = 0.56, p = 0.025, and r = 0.59, p = 0.016, respectively). The high-BDNF subgroup had a higher LDAEP and total BHS score than the low-BDNF subgroup (p = 0.046 and p = 0.011, respectively). This is the first study to demonstrate a relationship between the BDNF level and LDAEP in Asian depressive patients. Intriguingly, the high-BDNF subgroup (divided according to illness severity) exhibited a more severe psychopathology on some psychometric rating scales, a finding that conflicts with previous results.

Lower serum brain-derived neurotrophic factor levels are associated with failure to achieve remission in patients with major depression after escitalopram treatment

BACKGROUND

Remission, the primary goal of treatment for major depressive disorder (MDD), is the absence of significant signs or symptoms and the return to a state of normal functioning. A recent study found that the level of brain-derived neurotrophic factor (BDNF) increased after antidepressant treatment in remitted patients. This study evaluated serum BDNF levels in MDD patients with chronic maintenance treatment, and compared these between remission and nonremission groups.

MATERIALS AND METHODS

Serum BDNF levels were measured in 34 MDD patients and 35 healthy controls. The severity of depression was measured using the Hamilton Depression Rating Scale (Ham-D). The MDD patients were divided into remission and nonremission groups according to a cutoff total Ham-D score of either ≤7 or ≤6.

RESULTS

Serum BDNF levels differed significantly between the remission, nonremission, and healthy control groups (P<0.05). The Bonferroni post hoc test confirmed that serum BDNF levels were significantly lower in the nonremission group than in the healthy-control group (P<0.05), but did not differ significantly between the remission and healthy-control groups.

LIMITATIONS

This study included a small sample, and measured serum BDNF levels in the MDD patients at only one point during the maintenance treatment.

CONCLUSION

This study found that serum BDNF levels during maintenance treatment were lower in MDD patients with failure to achieve remission than in controls, while the remitted subjects had normalized serum BDNF levels. A lower level of serum BDNF during maintenance treatment is associated with failure to achieve remission in patients with major depression. Moreover, serum BDNF levels after chronic antidepressant treatment can be used as a biological marker for detecting nonremission.

Clinical characteristics of vivax malaria and analysis of recurred patients

Background

Plasmodium vivax malaria is an acute debilitating illness characterized by recurrent paroxysmal fever and relapses from hypnozoites in the liver. Although a few studies reported clinical characteristics of vivax malaria in civilians after reemergence in the Republic of Korea, only a small group of patients was analyzed.

Materials and Methods

We retrospectively reviewed the medical records of patients who had been diagnosed with vivax malaria by peripheral blood smear in a university-affiliated hospital located in a malaria-endemic area between January 2005 and December 2009.

Results

During the study period, a total of 352 malarial cases from 341 patients were diagnosed. Vivax malaria was most commonly developed in July and August, 24.7% (87/352), and 21.9% (77/352), respectively. The mean (SD) age was 42.5 (14.7) years and the number of male patients was 243 (71.3%). Six patients had a previous history of vivax malaria from 6 months to 10 years before. A total of 337 patients (98.8%) had fever and the mean (SD) body temperature was 38.3 (1.4)℃. Common associated symptoms were chills (213/341, 62.5%), headache (115/341, 33.7%), and myalgia (85/341, 24.9%). Laboratory findings included thrombocytopenia (340/341, 99.7%), anemia (97/341, 28.5%), leukopenia (148/341, 43.4%), increase of aspartate transaminase (177/341, 51.9%), and increase of alanine transaminase (187/341, 54.8%). Hypotension (14/341, 4.1%), altered mentality (3/341, 0.9%), azotemia (3/341, 0.9%), spleen infarction (2/341, 0.6%), and spleen rupture (1/341, 0.3%) developed as complications. Chloroquine was administered to all patients and primaquine was administered with mean (SD) 3.39 (0.82) mg/kg to 320 patients. There were 11 recurrent infections during the study period. The median (range) time to recurrent infection was 100 (32-285) days. Platelet counts were higher (86,550 vs. 56,910/mm³) and time to treatment of malaria was shorter (5 vs. 7 days) in relapsed cases compared with first occurrence cases (P=0.046).

Conclusions

The overall recurrence rate of vivax malaria was 3.2% (11/341) in this study. In recurred cases, malaria was diagnosed earlier and thrombocytopenia was less severe. To evaluate the risk factors associated with recurrence and adequate dose of primaquine in Korean patients, further large-scale prospective studies will be needed.

Prevalence and distribution of human papillomavirus infection in Korean women as determined by restriction fragment mass polymorphism assay

The development of a prophylactic vaccine that targets human papillomaviruses (HPV) 6, 11, 16, and 18 to prevent cervical cancer has increased interest in the ethnic and geographical distributions of HPV genotypes. We investigated HPV prevalence and type distribution by restriction fragment mass polymorphism (RFMP) testing a total of 60,775 specimens (aged 18-79 yr, median 44) taken from liquid-based cytology. Overall HPV positive rate of total patients was 34.2%. Among the positive patients, 87.7% was single type infections, and 12.3% was multiple HPV types. HPV-16 was the most prevalent genotype observed in 2,307 (26.0%), followed by type 52 in 2,269 (25.5%), type 58 in 1,090 (12.3%), type 18 in 633 (7.1%), type 56 in 436 (4.9%). The pattern of high risk-HPV positive rate according to age showed U-shape with a peak in HPV prevalence among women less than 30 yr of age, and a second peak among the older females aged 70 to 79 yr. The leading four high-risk HPV genotypes were HPV-16, HPV-52, HPV-58, and HPV-18 in descending order. In conclusion, this study provides the most representative prevalence and type-specific distribution of HPV among Korean women, and demonstrates that the epidemiology of HPV infection is different from that of other regions of the world.

Splenic infarction in a patient with autoimmune hemolytic anemia and protein C deficiency

Splenic infarction is most commonly caused by cardiovascular thromboembolism; however, splenic infarction can also occur in hematologic diseases, including sickle cell disease, hereditary spherocytosis, chronic myeloproliferative disease, leukemia, and lymphoma. Although 10% of splenic infarction is caused by hematologic diseases, it seldom accompanies autoimmune hemolytic anemia (AIHA). We report a case of a 47-year-old woman with iron deficiency anemia who presented with pain in the left upper abdominal quadrant, and was diagnosed with AIHA and splenic infarction. Protein C activity and antigen decreased to 44.0% (60-140%) and 42.0% (65-140%), respectively. Laboratory testing confirmed no clinical cause for protein C deficiency, such as disseminated intravascular coagulation, sepsis, hepatic dysfunction, or acute respiratory distress syndrome. Protein C deficiency with splenic infarction has been reported in patients with viral infection, hereditary spherocytosis, and leukemia. This is a rare case of splenic infarction and transient protein C deficiency in a patient with AIHA.

Detection and identification of human papillomavirus using a PCR-restriction fragment mass polymorphism assay

A polymerase chain reaction-restriction fragment mass polymorphism (PCR-RFMP) assay protocol using PGMY09/11 primers for the detection and identification of human papillomavirus (HPV) has recently been developed. The present study evaluated the analytical sensitivity and clinical utility of HPV genotyping employing PCR-RFMP as compared to direct sequencing. Serial dilutions of cloned HPV DNA were analyzed in order to assess the limit of detection (LOD) and three sets of HPV clone mixtures (types 16+18, 16+11 and 18+11) were used to assess the accuracy of the genotyping assays. For 423 cervical specimens that were cytologically categorized as normal or cancer, the concordance between the two assays was evaluated. Clinical sensitivity was calculated by evaluating 101 histologically confirmed cases. The PCR-RFMP HPV assay had a lower LOD and 100% accuracy when detecting double HPV infection. Agreement between the two assays upon 423 clinical specimens was 91.0% with a κ-value of 0.86. The incidence of multiple HPV infections among HPV-positive patients was 19.0% by PCR-RFMP and 5.4% by sequencing. The clinical sensitivity of PCR-RFMP and sequencing was 92% and 84%, respectively. In conclusion, the PCR-RFMP assay for HPV genotyping correlated well with direct sequencing, provides high analytical and clinical sensitivity, and is advantageous in the detection of multiple HPV infections.

Comparison of HPV genotyping assays and Hybrid Capture 2 for detection of high-risk HPV in cervical specimens

High-risk types of human papillomavirus (HR-HPV) are among the primary causes of cervical cancers. Hybrid Capture 2 (HC-II) (Digene, Gaithersburg, MD), which detects 13 HR-HPVs as a group, is the only HPV assay approved to date by the United States Food and Drug Administration. In Korea, several HPV genotyping assays are commercially available, including HPV RFMP (GeneMatrix Co., Seoul), HPVDNACHIP (Biomedlab Co., Seoul), and MyHPV Chip (Mygene Co., Seoul). We compared the results of these assays with those of HC-II. Among 553 residual samples of liquid-based Pap tests, a total of 435 (78.7%) were available for HPV assays. They were classified into four cytologic categories: normal, atypical squamous cells of undetermined significance (ASCUS), low-grade cervical squamous intraepithelial lesions (LSIL), and high grade SIL or carcinoma (HSIL+). Among these samples, 23.0%, 40.6%, 82.5%, 93.8% were HR-HPV positive by HC-II, respectively; 6.6%, 18.1%, 44.4%, 84.4%, by HPV RFMP, respectively; 5.7%, 24.5%, 54.0%, 84.4%, by HPVDNACHIP, respectively; and 6.6%, 11.6%, 42.9%, 84.4%, by MyHPV, respectively. Compared with HC-II, the concordance rates and kappa values were 70.6% and 0.421 for HPV RFMP; 75.4% and 0.514 for HPVDNACHIP; and 67.8% and 0.367 for MyHPV. The concordance rates and kappa values between genotyping assays were 85.1% and 0.644 for HPV RFMP and HPVDNACHIP; 83.4% and 0.574 for HPV RFMP and MyHPV Chip; and 82.8% and 0.579 for HPVDNACHIP and MyHPV Chip. In conclusion, compared with HC-II test, the genotyping tests showed more than fair concordance but lower sensitivity in the detection of HR-HPVs, limiting their usefulness as HR-HPV screening tools.

Eradication of Helicobacter pylori increases ghrelin mRNA expression in the gastric mucosa

It has been suggested that Helicobacter pylori eradication may influence production of some peptides in the stomach, which can affect appetite. This hypothesis is controversial. To verify the hypothesis, we conducted this randomized controlled trial using H. pylori infected subjects without any gastrointestinal symptoms. The treatment group received triple H. pylori eradication therapy for 7 days and the control group received no medication. We measured ghrelin, obestatin and the tumor necrosis factor-alpha (TNF-alpha) mRNA levels in endoscopic biopsy specimens and the changes from baseline to follow-up. The plasma active n-octanoyl ghrelin and obestatin levels were measured in both groups. The ghrelin/obestatin ratios in plasma and gastric mRNA expression were calculated at baseline and follow-up. Ghrelin mRNA expression in the fundic mucosa after H. pylori eradication increased significantly compared to the control group (4.47+/-2.14 vs. 1.79+/-0.96, P=0.009), independent of inflammatory changes. However, obestatin mRNA expression decreased in the antral mucosa (-0.57+/-1.06 vs. 0.41+/-0.72, P=0.028). The treatment group showed a marginal increase (P=0.060) in plasma ghrelin/obestatin ratio. The TNF-alpha mRNA expression also decreased significantly with treatment. This randomized controlled trial demonstrates that H. pylori eradication increases ghrelin mRNA expression, independent of inflammatory cell changes.

[Perception of the risks of blood transfusion in Koreans]

BACKGROUND

The perceived risks of blood transfusions are important to be considered in creating a blood service policy. We surveyed the perception of blood transfusion risks among Korean laypeople.

METHODS

A one-month nationwide telephone survey was conducted in September, 2007. The questionnaire was designed to assess the demographics of respondents, their responses to the term 'blood transfusion', and the perceived risks of a transfusion. A total of 500 interviews were completed.

RESULTS

The words evoked by the term 'blood transfusion' included blood, donation, AIDS, help, and patients. About one third (33.6-35.8%) of the respondents gave a moderate to high rating for the perceived risks of blood transfusions. More than half (55.6%) of the respondents agreed that the blood supply in Korea is safe, and 81.6% of the respondents agreed to be transfused when transfusion is needed. The perceived risk of a blood transfusion was greater in women than in men and in people who never had a transfusion than those who had. More men than women agreed that the blood supply in Korea is safe, and the proportion of respondents who agreed to be transfused when needed was higher in men and in less educated people. The relative perceived transfusion risk (scale of 10) was 4.5+/-2.3.

CONCLUSIONS

The Koreans in the survey had a tendency of positive thinking about blood transfusions, and previous transfusion experiences appear to decrease the fear about transfusions. These results will be useful in understanding how Koreans think about the risks associated with transfusions.

Neonatal hair nicotine levels and fetal exposure to paternal smoking at home

Exposure to environmental tobacco smoke (ETS) is a major risk to human health, and the home is the greatest single source of ETS for children. The authors investigated fetal exposure to paternal smoking at home during pregnancy. Korean families were included as trios of fathers, mothers, and neonates identified in 2005-2007. Sixty-three trios were finally enrolled in this study after exclusion of those in which the mother was a smoker or was regularly exposed to ETS at places other than the home. Nicotine and cotinine concentrations in hair were measured by using liquid chromatography-tandem mass spectrometry to determine long-term exposure to ETS. The difference between neonatal nicotine concentrations in the smoker and nonsmoker groups was not statistically significant. However, in the indoor-smoker group, neonatal nicotine concentrations were significantly higher than in the outdoor and nonsmoker groups (P < 0.05). Furthermore, neonatal nicotine concentrations in the outdoor-smoker group were not different from those in the nonsmoker group. These findings indicate that paternal smoking inside the home leads to significant fetal and maternal exposure to ETS and may subsequently affect fetal health. Conversely, findings show that paternal smoking outside the home prevents the mother and her fetus from being exposed to ETS.

[Microbiologic study of the bile culture and antimicrobial susceptibility in patients with biliary tract infection]

BACKGROUND/AIMS

Bacterial infection of biliary tract may cause severe inflammatory response or sepsis. An immediate bile culture and appropriate antibiotic administration are important to control the biliary tract infection. The objective of the study was to identify organisms in bile and the features of antibiotic susceptibility in patients with biliary tract infection.

METHODS

We retrospectively reviewed the clinical records of 212 patients whose bile had been cultured for variable biliary tract diseases at Inje University Ilsan Paik Hospital from Jan. 2000 to Feb. 2007. Bile samples were obtained from percutaneous transhepatic biliary drainage (PTBD, n=89), percutaneous transhepatic gallbladder drainage (PTGBD, n=14) or endoscopic naso-biliary drainage (ENBD, n=49).

RESULTS

The overall positive rate of bile culture was 71.7% (152 cases). The organisms cultured were Escherichia coli (25.0%), Enterococcus spp. (13.4%), Klebsiella spp. (11.1%), Pseudomonas spp. (11.1%), and coagulase-negative Staphylococcus (9.7%) in decreasing order. Effective antibiotics for Gram-negative organisms were amoxicillin/clavulanic acid, amikacin, imipenem, and piperacillin/tazobactam in order of effectiveness. Of the cultured blood samples from 160 patients, fifty (31.2%) showed positive bacterial growth. The organisms isolated from blood were similar to those found in the bile.

CONCLUSIONS

A broad spectrum penicillin/beta-lactamase inhibitor is a recommendable antimicrobial for empirical treatment for biliary tract infection. However, Gram-positive bacteria such as Enterococcus spp. or methicillin-resistant Staphylococcus aureus are emerging as causative microorganisms. If these organisms are isolated, antimicrobial drugs should be replaced by narrower-spectrum antimicrobials.

Morganella morganii sepsis with massive hemolysis

Morganella morganii is a facultative gram-negative and anaerobic rod. It may be a cause of devastating infections in neonates and immunocompromised hosts. Some bacterial infections such as Clostridium and Vibrio are associated with hemolysis. However, massive hemolysis caused by M. morganii sepsis has not yet been reported. We observed a 59-yr-old man who had chemotherapy-induced neutropenia and was found to have massive hemolysis and metabolic acidosis due to sepsis. He died 6 hr after admission in spite of aggressive treatment. Two sets of blood cultures revealed the growth of M. morganii. We report here that M. morganii sepsis can cause fatal massive hemolysis leading to death.

Frequency of neutrophil-specific antigens among Koreans using the granulocyte indirect immunofluorescence test (GIFT)

NA1, NA2, NB1, NB2, NC1, and NE1 are a group of antigens specifically expressed on neutrophils. Antibodies against neutrophil-specific antigens are involved in alloimmune neonatal neutropenia (ANN), autoimmune neutropenia (AIN), and transfusion-related acute lung injury (TRALI). We investigated the frequencies of NA1, NA2, NB1, and Mart antigens in 105 healthy Korean blood donors (65 males, 40 females) by the granulocyte indirect immunofluorescence test (GIFT) employing flow cytometry. Antigen and gene frequencies were: NA1, 0.78 and 0.53, respectively; NA2, 0.75 and 0.50, respectively; and NB1, 0.86 and 0.62, respectively. The Mart antigen was positive in all 105 subjects included in this study. The proportions of NB1-positive neutrophils among NB1-positive individuals were variable with a mean value of 72.0 +/- 20.2% (range, 27-100%). Differences in the frequency of the NA1 antigen have been reported between Asian and Caucasian populations. Our data support this variation. In addition, it was found that the frequency of the NA1 antigen in Koreans is significantly lower than in Japanese and Chinese populations (p < 0.05).