The authors calculated the number of blood cultures per 1,000 admitted patient days at seven university-affiliated hospitals in 2010, which ranged from 65 to 129 (mean 110). The number of blood cultures per 1,000 patient days could possibly be a good parameter for assessing the appropriateness of blood culture.
Humans ; Korea ; Quality Control ; Sepsis

BACKGROUND: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been used for the identification of bacteria worldwide. To our knowledge, the evaluation of MALDI-TOF MS for the identification of bacteria in Korea has not been studied. In this paper we compared the identification results of aerobic bacteria using MALDI-TOF MS to those results using conventional biochemical methods. METHODS: We evaluated the performance of a MALDI-TOF MS system (Bruker Daltonics, Leipzig, Germany) on consecutive aerobic isolates collected from January to February of 2011 which were identified using conventional methods (biochemical testing and commercial identification kits). Either directly smearing onto the target plate or protein extraction methods were additionally used if no reliable or discordant results were obtained. RESULTS: Among 523 isolates tested, 506 (97%) isolates had valid scores (> or =2.0), 11 (2%) isolates gave intermediate scores (1.7< or = score <2.0), and 6 (1%) isolates yielded no reliable identification (score <1.7). Of the 506 valid results (score > or =2.0) by MALDI-TOF MS, the identification matched at the species level in 486 (96%) isloates, matched at the genus level in 17 (3%) isloates, and was discordant at the genus and species levels in 3 (1%) isloates. CONCLUSION: The overall matching rate at the species level of MALDI-TOF MS was very high. When MALDI-TOF MS did not yield reliable results by direct smear, additional direct smears or protein extraction methods could be used to obtain better results. Our results showed that MALDI-TOF MS is a very useful method for the identification of aerobic bacteria isolated in clinical microbiology laboratories.
Bacteria ; Bacteria, Aerobic ; Korea ; Mass Spectrometry

BACKGROUND: Parainfluenza virus (PIV) is a significant cause of acute respiratory infections. Epidemiological information on PIV infection could be very helpful for patient management. The aim of this study was to investigate the epidemiology of PIV infection in Seoul and a neighboring area with regard to PIV type. METHODS: The diagnosis of PIV infection was made by virus isolation. The R-mix Too cell system (Diagnostic Hybrids, Inc., Athens, OH, USA) and D3 Ultra DFA Respiratory Virus Screening & ID kits (Diagnostic Hybrids, Inc.) were used for virus culture and identification. The medical records of patients with positive virus cultures were reviewed retrospectively. RESULTS: Seven hundred and ten PIV viruses (5.6%) were isolated from 12,723 specimens. The number of subjects with PIV type III, I and II was 357, 304 and 49, respectively. PIV infection showed a peak incidence in the first year of life regardless of subtypes. The most common diagnosis among all PIV subtypes was pneumonia. Lower respiratory tract infections constituted the majority (76.3%) of PIV infections. The most common diagnosis of PIV type I and II was croup and that of PIV type III was pneumonia. A difference in seasonal variation between subtypes was observed. PIV I (62.2%) was mainly isolated from July to September while PIV type III (86.8%) was isolated from April to July. CONCLUSION: Lower respiratory infection was most commonly found in hospitalized patients with PIV infection. Clinical features of PIV infection were similar those seen in Western PIV reports, with the exception of the seasonal outbreak pattern.
Chimera ; Croup ; Humans ; Incidence ; Mass Screening ; Medical Records ; Parainfluenza Virus 1, Human ; Paramyxoviridae Infections ; Pneumonia ; Respiratory Tract Infections ; Seasons ; Viruses

BACKGROUND: The female genital tract is equipped to deal with a variety of foreign substances including a wide array of microorganisms. It is important to consider Candida-bacterial interactions in balance between healthy colonization versus vaginitis. The objectives of this study were to evaluate the association between microorganism distribution and vaginitis, and to investigate the possibility of an interaction between vaginal Candida and other microorganisms in female genital tract. METHODS: A total of 516 vaginal secretions were collected between October 2008 and June 2010 from patients with suspected vaginitis. Identification of Candida species and detection of 6 fastidious microorganisms (Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma hominis, Mycoplasma genitalium, and Ureaplasma urealyticum) were performed using a VITEK 2 system (bioMerieux, Inc., Hazelwood, MO, USA) and multiplex PCR (Seegene, Biotechnology, Inc., Seoul, Korea), respectively. RESULTS: M. genitalium, U. urealyticum, and C. trachomatis were more often detected in association with vaginal candidiasis. A statistically significant association between Candida and M. genitalium was observed (P<0.05). N. gonorrhoeae was detected less often in women with vaginal candidiasis. CONCLUSION: The results of this study suggest the possibility that vaginal Candida may associate with some microorganisms in patients with vaginitis. Further studies will be required to define the Candida-bacterial interactions and its mechanisms.
Bacteria ; Biotechnology ; Candida ; Candidiasis ; Chlamydia trachomatis ; Colon ; Female ; Humans ; Microbial Interactions ; Multiplex Polymerase Chain Reaction ; Mycoplasma genitalium ; Mycoplasma hominis ; Neisseria gonorrhoeae ; Trichomonas vaginalis ; Ureaplasma ; Vaginitis

The global emergence and spread of multidrug resistant bacterial infections in communities and hospitals has become an important issue in public health. The resistance rate of gram-positive cocci to vancomycin and the resistance rate of several gram-negative bacilli against cefotaxime and carbapenem have been continuously increasing. Surveillance of antimicrobial resistance is essential for providing information on the magnitude of and trend in multidrug resistance. Therefore, beginning 2011, more robust and effective management is to be legally required for six multidrug-resistant bacteria that have been linked to healthcare-related infections: vancomycin-resistant Staphylococcus aureus (VRSA), vancomycin-resistant enterococci (VRE), methicillin-resistant S. aureus (MRSA), multidrug-resistant Pseudomonas aeruginosa (MRPA), multidrug-resistant Acinetobacter baumannii (MRAB), and carbapenem-resistant Enterobactericeae (CRE). We have also performed laboratory-based sentinel surveillance for VRSA/VISA since 2002 and carbapenemase-producing Enterobacteriaceae since November, 2010. This article reviews the national surveillance programs, and molecular epidemiology of multidrug-resistant bacteria.
Acinetobacter baumannii ; Bacteria ; Bacterial Infections ; Cefotaxime ; Drug Resistance, Multiple ; Enterobacteriaceae ; Gram-Positive Cocci ; Methicillin Resistance ; Molecular Epidemiology ; Nitriles ; Pseudomonas aeruginosa ; Public Health ; Pyrethrins ; Sentinel Surveillance ; Staphylococcus aureus ; Vancomycin

Exflagellation of the malaria parasite microgametocyte usually occurs in the gut cavity of Anopheles mosquitoes following an infective blood meal. Exflagellation is a very rare event in human blood. Due to its rarity, the appearance of this structure in a peripheral blood smear will easily create a diagnostic dilemma. We report a case of malaria with exflagellated microgametes in human blood that was initially mistaken for a double infection of Plasmodium and another blood flagellate. The patient was a 29-year-old Parkistani man presenting with fluctuating fever accompanied by chills and fatigue for 4 days. Initial peripheral blood smear examination showed a number of Plasmodium ring forms, trophozoites, and gametocytes. Additionally, several filamentous structures resembling blood flagellates were seen. With these features, an initial diagnostic impression of combined infection of malaria and blood flagellate was made. Later, we determined that these structures resembling blood flagellates were exflagellated microgametes of malarial parasite. Therefore, the knowledge that exflagellation may appear in human blood with Plasmodium species infection and being more familiar with differentiation of the morphologic features of other species infection can prevent further possible misinterpretation.
Anopheles ; Chills ; Culicidae ; Fatigue ; Fever ; Humans ; Malaria ; Meals ; Parasites ; Plasmodium ; Trophozoites

Neisseria flavescens has been rarely reported as a pathogen in the literature. We experienced a case of N. flavescens bacteremia and lung abscess co-infected with Streptococcus sanguis in patient with idiopathic hypereosinophilic syndrome. A 15-year-old boy was diagnosed with idiopathic hypereosinophilic syndrome complicated with pulmonary thromboembolism. He was given systemic steroids and thrombolytics. After 8 weeks of therapy, a lung abscess appeared on the plain chest radiograph. We treated him with empirical antibiotics and carried out surgical drainage. Two types of microorganisms were cultured from both blood and pus samples, obtained in the first day of hospitalization. Pus was aspirated from the lung abscess with an aseptic technique. Neisseria species and S. sanguis were identified using traditional methods. To confirm the identity of the Neisseria species, we conducted further testing using 16S ribosomal ribonucleic acid sequencing whereupon N. flavescens was identified. This is the first case report of pulmonary infection caused by N. flavescens. We suggest that N. flavescens may act as a pathogen.
Anti-Bacterial Agents ; Bacteremia ; Drainage ; Hospitalization ; Humans ; Hypereosinophilic Syndrome ; Lung ; Lung Abscess ; Neisseria ; Pulmonary Embolism ; RNA ; Sepsis ; Steroids ; Streptococcus ; Streptococcus sanguis ; Suppuration ; Thorax

Arcanobacterium haemolyticum, a aerobic Gram-positive rod, has been described as an unusual pathogen causing soft tissue infections such as pharyngotonsillitis, chronic ulcer and cellulitis. In addition, the microorganism causes deep-seated infection and systemic disease including endocarditis, vertebral osteomyelitis and sepsis in patients with predisposing conditions such as diabetes mellitus. Since colonies and microscopic findings of A. haemolyticum might be confused with those of streptococci and coryneform bacteria, and it is usually isolated with other microorganisms, it is often considered to be normal flora or a contaminant in wound infections, resulting in missed or delayed diagnosis. Streptococcus agalactiae infections in neonates and pregnant women have been well recognized. However, invasive S. agalactiae infections in non-pregnant older adults with chronic medical conditions, particularly diabetes mellitus, are increasing. We report a case of diabetic foot ulcer due to A. haemolyticum and S. agalactiae in an uncontrolled diabetes mellitus patient.
Adult ; Arcanobacterium ; Bacteria ; Cellulitis ; Delayed Diagnosis ; Diabetes Mellitus ; Diabetic Foot ; Endocarditis ; Female ; Humans ; Infant, Newborn ; Osteomyelitis ; Pregnant Women ; Sepsis ; Soft Tissue Infections ; Streptococcus ; Streptococcus agalactiae ; Ulcer ; Wound Infection

Blood culture-negative infective endocarditis (CNE) can be a diagnostic dilemma. Herein, we report a case of CNE caused by Haemophilus parainfluenzae identified only via 16S rRNA sequence analysis directly from valve tissue. A 17-year-old boy presented with high spiking fever for one month. Pansystolic murmur (Grade III) and vegetation (0.65x0.26 cm and 0.62x0.55 cm) on the anterior mitral valve leaflet via transesophageal echocardiogram suggested the diagnosis of infective endocarditis (IE). However, blood culture performed on admission was negative even after 2 weeks of incubation. Gram stain and culture of a direct tissue specimen failed to identify causative microorganism, while 16S rRNA gene sequences (548 bp) showed 100% identity with those of Haemophilus parainfluenzae (GenBank: FJ939586.1). The 16S rRNA sequence analysis with a direct tissue specimen might be useful in cases of CNE.
Endocarditis ; Fever ; Genes, rRNA ; Haemophilus ; Haemophilus parainfluenzae ; Mitral Valve ; Sequence Analysis

BACKGROUND: Metallo-beta-lactamase-mediated carbapenem resistance has been increasingly reported in Pseudomonas, Acinetobacter and other Gram-negative bacilli (GNB) in many countries. A few studies showed highly variable structure of MBL-gene cassette-carrying integrons. The aim of this study was to determine the structure of blaVIM-2-carrying integrons in Pseudomonas and Acinetobacter. METHODS: blaVIM-2-carrying GNB were isolated at a Korean hospitals during the years 1995-1999 and 2005. The size of blaVIM-2-carrying integrons was estimated by the PCR products. Representative integrons were sequenced by the dideoxy-chain termination method. The MICs of antimicrobial agents were tested by the CLSI agar dilution methods. RESULTS: During the years 1995-1999 and 2005, the approximate size of the blaVIM-2-carrying class 1 integrons was 3-7 kb in 35 Pseudomonas isolates and 3-5 kb in 24 Acinetobacter isolates. The integrons carried one-five resistance gene cassettes in addition to the blaVIM-2 cassette. Other resistance gene cassettes found were blaOXA-1, aacA1, aac(6')-I, and aac(6')-II. Interestingly, sequences homologous to part of a putative class II intron were inserted into the recombination site of the last cassette in four of nine integrons. The class 1 integron from P. aeruginosa isolates had fused orf/IntI1 in a downstream leftward inverted repeat (IRi). CONCLUSION: According to period, the size and structure of blaVIM-2-carrying integrons are quite variable, but an identical one is also present in a different genus, indicating high mobility of the blaVIM-2 cassette and horizontal transfer of the whole integron. We suggest that the class 1 integron containing the blaVIM-2 gene is spreading horizontally among Gram-negative bacilli and is undergoing continuous development in Korea.
Acinetobacter ; Agar ; Anti-Infective Agents ; Integrons ; Introns ; Korea ; Lifting ; Polymerase Chain Reaction ; Pseudomonas ; Recombination, Genetic