BACKGROUND: Staphylococcus aureus produces siderophore and expresses transferring-binding protein for uptake of iron essentially required for multiplication under the iron-restricted conditions. We investigated which of the two iron-uptake systems is dominant or essential for S. aureus growth. METHODS: Streptonigrin-resistant mutant (SR-1) of S. aureus, isolated by repeated exposure to streptonigrin, was used in this study. SR-1 strain produced less amount of siderophore than the parent strain and did not express the transferring-binding protein. Growth and iron consumption of the two bacteria were compared during cultivation in the media containing various concentrations of iron, by measuring optical densities of the culture fluids at 600 nm and residual iron concentrations of the culture supernatants. RESULTS: Growth of the two bacteria in the iron-sufficient media containing various sources of iron was more active than in the iron-deficient media, in which iron concentration was 0.2 microgram/dL. Growth of SR-1 strain was markedly inhibited in the iron-deficient media with/without apotransferrin (0.5 mg/mL). However, growth of SR-1 strain did not show any difference in the iron-sufficient media containing FeCl3 (0.2 micrometer) and hemoglobin (0.5 mg/mL) as compared with that of the parental strain. Moreover, growth of the two bacteria did not show any difference in the media containing holotransferrin (0.5 mg/mL). There was no difference in iron consumption between the parental and mutant strains, evidenced by the residual iron concentration of the culture supernatants. CONCLUSION: Siderophore production is thought to be dominant or essential iron-uptake system for in vitro growth of S. aureus. The pathogenetic role of multifunctional transferring-binding protein, including transferring-binding activity and glycolytic enzyme activity, is expected to be established through further continued studies.
Bacteria ; Carrier Proteins* ; Humans ; Iron ; Parents ; Staphylococcus aureus* ; Staphylococcus* ; Streptonigrin ; Transferrin*

BACKGROUND: Measles is a highly infectious disease throughout the world and has not yet been eradicated with aggressive vaccination in Korea since 1960's. Recently, measles outbreaks have occurred periodically every 2 to 4 years. Unlike measles in children, few clinical studies on the measles of adult in our domestic area were carried out. In this study, we analyzed epidemiologic and clinical features of adult measles patients. METHODS: From January to June in 2001, 23 adult measles patients were admitted in Sun general hospital in Daejeon. Epidemiologic findings, clinical course, and laboratory findings were reviewed retrospectively. RESULTS: Measles was predominant in male patients (M : F=2.3 : 1). Many of the patients were late teenagers and early twenties. Major symptoms were fever (100%), cough (100%), rash (100%), diarrhea (69.6%), vomiting (60.9%), headache (60.9%), rhinorrhea (30.4%), and sore throat (30.4%). Koplik spot was observed in 11 (47.8%) patients. Rash appeared 1-6 days after the onset of fever. Fever lasted for 5-9 days and cough lasted for 10-14 days. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were elevated in 12 (52.2%) and 9 (39.1%) patients, respectively. Only 14 (60.9%) patients were seropositive for measles specific IgG antibody, but all the patients were seropositive for measles specific IgM antibody. No fatal complication was observed. CONCLUSION: Gastrointestinal symptom and hepatic dysfunction were the clinical characteristics of adult measles outbreak in Daejeon, 2001. Different from previous studies, all patients were seropositive for measles specific IgM antibody.
Adolescent ; Adult* ; Alanine Transaminase ; Aspartate Aminotransferases ; Child ; Communicable Diseases ; Cough ; Diarrhea ; Disease Outbreaks ; Exanthema ; Fever ; Headache ; Hospitals, General ; Humans ; Immunoglobulin G ; Immunoglobulin M ; Korea ; Male ; Measles* ; Pharyngitis ; Retrospective Studies ; Solar System ; Vaccination ; Vomiting

BACKGROUND: The present study was performed to evaluate clinical usefulness of pp65 antigenemia assay (pp65 Ag), plasma polymerase chain reaction (P-PCR) and peripheral blood mononuclear cell PCR (PBMC-PCR) in patients with cytomegalovirus (CMV) diseases. METHODS: Sixty samples from 41 patients admitted in Seoul National University Hospital from Sep, 2001 through Feb, 2002 were evaluated. Twenty-eight patients who had symptoms and signs of CMV disease and 13 patients who were asymptomatic were tested for CMV infection. Among 60 samples, 59 samples were tested for pp65 Ag by Clonab CMV kit (Biotest, Dreieich, Germany). Fifty-six samples were tested for P-PCR and PBMC-PCR, respectively. RESULTS: Fifteen (25%) out of 59 samples showed positive by pp65 Ag, 16 (29%) and 24 (43%) out of 56 samples showed positive by P-PCR and PBMC-PCR, respectively. The concordance rate of pp65 Ag and P-PCR in the same blood sample was 82%. CMV disease was diagnosed in 15 (37%) patients. The sensitivities of pp65 Ag, P-PCR and PBMC-PCR were 60, 53 and 80%, respectively, and in specificities were 96, 92, 88%, respectively. Of the 15 patients with CMV diseases, 4 patients who underwent allogenic bone marrow transplantation showed positive results by all the three assays, and the number of pp65 positive cells in these patients was high (3-30/4X10(5)). Eight out of the 15 patients with CMV diseases had CMV gastroenteritis. Four of them showed positive by pp65 Ag(the number of pp65 positive cells : 1-3/4X10(5)) and 2 patients showed positive by P-PCR. CONCLUSION: The senstivity of PBMC-PCR was high and the specificity was relatively low. It is quite likely PBMC-PCR was not able to distinguish CMV reactivation from latent infection. The sensitivity and specificity of pp65 Ag were similar to those of P-PCR. CMV pp65 positive cells could be quantitated by pp65 Ag.
Bone Marrow Transplantation ; Cytomegalovirus ; Diagnosis* ; Gastroenteritis ; Humans ; Plasma ; Polymerase Chain Reaction* ; Sensitivity and Specificity ; Seoul

BACKGROUND: Multidrug-resistant tuberculosis is an increasing concern for public health in many parts of the world. We have evaluated the specificity and sensitivity of the mismatch assay and 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay in detecting rifampin- resistant Mycobacterium tuberculosis. METHODS: Eleven rifampin-susceptible and 15 rifampin-resistant M. tuberculosis strains were isolated from clinical specimens obtained from patients in Yonsei University College of Medicine, Severance Hospital. RNA/RNA duplex, base pair-mismatch assay (Mismatch Detect II kit, Ambion) and MTT assay were performed. RESULTS: The specificity and sensitivity of detection of rifampin resistance were 91% and 87% in mismatch assay and 73% and 67% in MTT assay, respectively. CONCLUSION: These results suggest the usefulness of mismatch assay in detecting rifampin-resistant Mycobacterium tuberculosis.
Humans ; Mycobacterium tuberculosis* ; Mycobacterium* ; Public Health ; Rifampin ; Sensitivity and Specificity ; Tuberculosis ; Tuberculosis, Multidrug-Resistant

BACKGROUND: Rhinovirus has long been considered as the most important cause of uncomplicated upper respiratory infection and a trigger of asthma exacerbation, and was recently been widely appreciated for it's association with lower respiratory tract illness. METHODS: One hundred and sixty-six children with lower respiratory tract infections were enrolled. They had been hospitalized at the Seoul National University Children's Hospital from August 1997 to March 2000. All the children had been previously healthy and under 5 years of age. Rhinovirus was detected in nasal aspirates by semi-nested reverse transcription polymerase chain reaction and confirmed by digestion pattern of the amplicon with a restriction enzyme. Presence of other respiratory pathogens was also analysed. RESULTS: Of the 166 children, rhinoviruses were detected in 8 children (4.8%). Majority of rhinovirus was detected in the patients who had been hospitalized in the late fall and winter, and all the infected children recovered completely. Other respiratory pathogens identified were; mycoplasma in 7 (4.2%), respiratory syncytial virus in 15 (9.0%), parainfluenza virus in 8 (4.8%), adenovirus in 4 (2.4%) and influenza virus in 3 (1.8%). CONCLUSION: Rhinovirus may be a significant cause of acute lower respiratory infections in healthy children. Further investigation on the diagnosis and clinical characteristics of rhinoviral infection is warranted.
Adenoviridae ; Asthma ; Child* ; Diagnosis ; Digestion ; Humans ; Mycoplasma ; Orthomyxoviridae ; Paramyxoviridae Infections ; Polymerase Chain Reaction* ; Respiratory Syncytial Viruses ; Respiratory System* ; Respiratory Tract Infections* ; Reverse Transcription* ; Rhinovirus* ; Seoul

Prognosis has not been known for patients with fever of unknown origin (FUO) whose ¹⁸fluoro-deoxyglucose (¹⁸F-FDG) positron emission tomography/computerized tomography (PET/CT) finding is non-diagnostic. A total of eight patients with FUO that underwent ¹⁸F-FDG PET/CT were retrospectively identified January 2016 - June 2017 in a tertiary hospital in Korea. Of these, two patients were diagnosed with microscopic polyangitis and Kikuchi's disease and one patient was transferred to another hospital. Of five patients whose diagnoses were not confirmed, four patients received non-steroidal anti-inflammatory drug and/or low dose steroid and symptoms disappeared. Our study suggests that outcome of patients with FUO whose ¹⁸F-FDG PET/CT finding is non-diagnostic would be favorable.
Diagnosis ; Electrons* ; Fever of Unknown Origin* ; Fever* ; Histiocytic Necrotizing Lymphadenitis ; Humans ; Korea ; Positron-Emission Tomography and Computed Tomography ; Prognosis ; Retrospective Studies ; Tertiary Care Centers

BACKGROUND: This study aimed to evaluate the epidemiology, clinical and microbiological features, treatment, and outcomes of infective endocarditis (IE) on the island of Crete, a region with high levels of antimicrobial resistance. MATERIALS AND METHODS: Medical records of all hospitalized patients diagnosed with IE at the University Hospital of Heraklion, Crete, Greece, from 1995 to 2015, were retrospectively reviewed. Patients who met the modified Duke's criteria for definite or possible IE were included. RESULTS: A total of 82 IE patients (median age 67 [range 21–86] years) were included. Most patients suffered from left-sided IE (94%), while most cases of infection occurred in native valves (53.6%). Systemic inflammatory response syndrome criteria were lacking in almost half of the patient population. The leading causative microorganism was Staphylococcus aureus, isolated in 24 cases (29%), followed by Streptococcus spp. in 15 (18%) and Enterococcus spp. in 12 (14.5%). A number of rare and difficult to treat microorganisms had been identified, such as Gemella morbillorum in four cases (4.5%), Streptococcus lugdunensis in two (2.5%) and Streptococcus pneumoniae in one (1%). One patient was serologically positive for Coxiella burnetii (1%). All patients received empirical antimicrobial treatment, proven appropriate in 39 blood culture-positive patients (56.5%). Thirteen (16%) patients were classified as culture negative. Seven patients (8.5%) were surgically treated. In-hospital death occurred in 9 patients (11%). CONCLUSION: Changes in IE profile requires continuous epidemiological updates. Staphylococcus and Streptococcus spp. remain the most common etiologic agents. However, the presence of uncommon and/or difficult to treat pathogens raise concerns on the appropriate prophylaxis as well as empirical treatment.
Coxiella burnetii ; Endocarditis* ; Enterococcus ; Epidemiology* ; Gemella ; Greece* ; Humans ; Medical Records ; Retrospective Studies ; Staphylococcus ; Staphylococcus aureus ; Streptococcus ; Streptococcus pneumoniae ; Systemic Inflammatory Response Syndrome ; Treatment Outcome

In addition to being the prime factor associated with amputation, diabetic foot infections (DFIs) are associated with major morbidity, increasing mortality, and reduced quality of life. The choice of appropriate antibiotics is very important in order to reduce treatment failure, antimicrobial resistance, adverse events, and costs. We reviewed articles on microbiology and antimicrobial therapy and discuss antibiotic selection in Korean patients with DFIs. Similar to Western countries, Staphylococcus aureus is the most common pathogen, with Streptococcus, Enterococcus, Enterobacteriaceae and Pseudomonas also prevalent in Korea. It is recommended that antibiotics are not prescribed for clinically uninfected wounds and that empirical antibiotics be selected based on the clinical features, disease severity, and local antimicrobial resistance patterns. Narrow-spectrum oral antibiotics can be administered for mild infections and broad-spectrum parenteral antibiotics should be administered for some moderate and severe infections. In cases with risk factors for methicillin-resistant S. aureus or Pseudomonas, empirical antibiotics to cover each pathogen should be considered. The Health Insurance Review and Assessment Service standards should also be considered when choosing empirical antibiotics. In Korea, nationwide studies need to be conducted and DFI guidelines should be developed.
Amputation ; Anti-Bacterial Agents ; Diabetic Foot* ; Enterobacteriaceae ; Enterococcus ; Humans ; Insurance, Health ; Korea ; Methicillin Resistance ; Mortality ; Pseudomonas ; Quality of Life ; Risk Factors ; Staphylococcus aureus ; Streptococcus ; Treatment Failure ; Wounds and Injuries

Albendazole (ADZ) and praziquantel (PZQT) have been used as anthelmintics for over 30 years. Worldwide, hundreds of millions tablets are administered to people and livestock every year. ADZ is poorly orally absorbed (< 5%), and its uptake is enhanced by high-fat meals, while PZQT is well absorbed (> 75%) and uptake is enhanced by carbohydrate-rich meals. Both ADZ and PZQT are safe, but not recommended for children < 2 years or for women in the first trimester of pregnancy. Serious adverse events occur following high dose and prolonged administration of these drugs for treatment of echinococcosis or neurocysticercosis, especially in patients with poor liver function. The adverse events may be induced by the drugs, or by the dead worms themselves. The Korea Institute of Drug Safety & Risk Management monitors drug-related adverse events in Korea, and its database included 256 probable or possible ADZ-associated events and 108 PZQT-associated events between 2006 and 2015. Such low incidence rates in Korea are due to the low single dose treatments of ADZ, and the short-term use of PZQT. The number of serious adverse events due to drug interaction induced by ADZ and PZQT were six and two, respectively. We conclude that ADZ and PZQT are generally safe drugs, but they must be used with caution in people with poor liver function or those being comedicated for gastroesophageal reflux disease.
Albendazole* ; Anthelmintics ; Child ; Drug Interactions ; Echinococcosis ; Female ; Gastroesophageal Reflux ; Humans ; Incidence ; Korea* ; Liver ; Livestock ; Meals ; Mebendazole ; Neurocysticercosis ; Praziquantel* ; Pregnancy ; Pregnancy Trimester, First ; Risk Management ; Tablets

BACKGROUND: Since the first Korean case of human brucellosis was reported in 2002, the incidence of human brucellosis has been rapidly increasing. We performed this study to evaluate the clinical characteristics of human brucellosis occurring in South Korea. MATERIALS AND METHODS: Demographic features, clinical manifestations, and therapeutic outcomes of cases confirmed as brucellosis according to WHO diagnostic criteria were evaluated. Species of Brucella isolates were identified with 16S rRNA gene sequencing method. Serologic diagnosis was performed with standard tube agglutination test (STA). RESULTS: A total of 34 cases were enrolled from 2003 to 2006 in six hospitals. Eight cases were confirmed with the isolation of Brucella from blood and 26 cases were confirmed with titer of antibodies < or =1:160 by STA. Male (31) was predominant and most of the patients were cattle farmers. The most common transmission route was direct contact with infected or their cattle byproducts. Fever was the most prominent symptom and fatigue followed. Gastrointestinal and musculoskeletal systems were commonly complicated. Patients were treated with doxycycline and rifampin or aminoglycosides for more than 6 weeks. All patients responded well to the therapeutic regimens, but one patient relapsed 10 months after treatment. CONCLUSION: Brucellosis occurring in Korea has been caused by B. abortus, whose preferred natural host animals are cattle. Korean patients were infected through direct contact with bovine brucellosis. Clinical manifestations of brucellosis were similar to those occurring worldwide. Therapeutic outcomes were good among patients with brucellosis in Korea. In order to prevent human brucellosis, measures to eradicate bovine brucellosis should precede.
Agglutination Tests ; Aminoglycosides ; Animals ; Antibodies ; Brucella ; Brucella abortus ; Brucellosis* ; Brucellosis, Bovine ; Cattle ; Diagnosis ; Doxycycline ; Fatigue ; Fever ; Genes, rRNA ; Humans* ; Incidence ; Korea* ; Male ; Musculoskeletal System ; Rifampin