BACKGROUND: Viruses that cause acute respiratory infection include adenovirus (ADV), respiratory syncytial virus A and B (RSV(A), RSV(B)), influenza virus A and B (FluA, FluB), parainfluenza virus 1, 2 and 3 (PIV1, PIV2, PIV3), human metapneumovirus (hMPV), human coronavirus (hCoV), human rhinovirus (hRV), and enterovirus, among others. METHODS: Viral incidence was evaluated in acute respiratory patients in Seoul, Korea from 2010 to 2012. A total of 2,544 oropharyngeal swab specimens were tested by real-time polymerase chain reaction (PCR) methods. RNA viruses (hRV, PIV, RSV, hCoV, and hMPV) and DNA viruses (ADV and bocavirus) were detected using the one-step reverse transcriptase PCR (RT-PCR) premix kit (SolGent, Korea) from January 2010 to June 2011, and using the real-time PCR kit (Kogenebiotech, Korea) from July 2011 to December 2012. RESULTS: Thirty-two percent (813/2,544) of specimens were positive; 31.9% (294/923) in 2010, 31.4% (232/738) in 2011, and 32.5% (287/883) in 2012. The most frequently isolated virus was hRV (40.7%, 331/813), followed by ADV (23.9%, 194/813), RSV (14.1%, 115/813), PIV (12.3%, 100/813), and hCoV (8.7%, 71/813). PIV1 was the most commonly isolated PIV, followed by PIV3 and PIV2, respectively. hCo OC43 was the most commonly isolated hCoV, followed by hCoV NL63 and hCoV 229E, respectively. CONCLUSION: Information on respiratory viruses circulating in Seoul, Korea over the last three years will be helpful in the management of acute respiratory infections, and for larger-scale epidemiological studies.

BACKGROUND: Antimicrobial resistance of Neisseria gonorrhoeae has become a serious problem worldwide, and ceftriaxone non-susceptible isolates have been recently reported from Japan and Europe. In this study, we evaluated the antimicrobial susceptibilities and molecular epidemiological characteristics of isolates from Korea in 2013. METHODS: Sixty strains of N. gonorrhoeae were collected from Korean patients and prostitutes. Antimicrobial susceptibility was tested by the agar dilution and disk diffusion methods. N. gonorrhoeae multi-antigen sequence typing (NG-MAST) was performed in order to determine the molecular epidemiologic relatedness. RESULTS: All of isolates were non-susceptible to penicillin G and tetracycline, and the rate of ciprofloxacin-resistant isolates was 95% in 2013. The MICs of ceftriaxone were within the susceptible range for all isolates, but one isolate non-susceptible to cefixime (MIC=0.5 microg/mL) was encountered. The isolates with decreased susceptibility (MIC< or =0.12 microg/mL) to cefixime or ceftriaxone accounted for 10% and 14% of the isolates tested, respectively. In NG-MAST analysis, 40 different STs were encountered among the 59 isolates. Isolates that belonged to tbpB110 showed higher cefixime and ceftriaxone MICs (0.12-0.5 microg/mL) as well as cefixime resistance. CONCLUSION: Most of the N. gonorrhoeae isolates showed susceptibility to spectinomycin and cephalosporins. Due to the emergence of isolates that are non-susceptible to cefixime and the prevalence of isolates with the tbpB110 allele belonging to ST1407, which cause cefixime and ceftriaxone treatment failure in successful global clones of N. gonorrhoeae, a continuous nationwide antimicrobial surveillance program is required to monitor the emergence of cephalosporin resistance in N. gonorrhoeae.

BACKGROUND: Through change in the climate and living environment, bacterial pathogens that cause diarrhea also change. This study sought to determine the characteristics of pathogens according to species, isolated region, and patient age/sex using National Surveillance Data for diarrhea, and to provide basic data for the prevention of diarrheal disease. METHODS: From January to December 2012, stool specimens were collected from 21,180 diarrheal patients in Korea to identify the pathogenic bacteria involved. Pathogenic bacteria were analyzed according to isolated region and patient age/sex. Identification and analysis of the pathogens were conducted based on the Guidelines of the National Institute of Health Diagnostic Laboratory: Disease-specific protocol (2005). RESULTS: Among the 21,180 stool specimens, pathogenic bacteria known to cause diarrhea were isolated from 2,444 stool specimens (11.5%). The isolation rate was highest in the summer (from June to September) for most pathogenic bacteria, except Escherichia coli, Staphylococcus aureus, and Clostridium perfringens. The isolation rate of pathogenic bacteria based on patient age was highest in children under the age of 10. CONCLUSION: Hygiene education should be addressed in diarrheal disease-susceptible groups, such as children under 10, people in their 50s, and those greater than 70 years old, and ongoing monitoring for pathogens is needed. In addition, an efficient information system and surveillance program should be continued for infection prevention.

BACKGROUND: This study compared the growth of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Haemophilus influenzae in blood culture bottles containing anticoagulants, sodium polyanethol sulfonate (SPS) and sodium citrate. METHODS: One hundred and fifty colony forming units of five different bacterial species were inoculated into standard aerobic (SA) and standard anaerobic (SN) bottles and were combined with 5 mL of human blood in solution with SPS or sodium citrate. Time to detection (TTD) was then monitored using the BacT/Alert 3D system (bioMerieux Inc.). RESULTS: Compared to the bacteria-only controls, cultures containing S. aureus, E. coli, P. aeruginosa, and S. pneumoniae plus SPS blood or citrated blood trended toward reduced TTD in both SA and SN bottles; however, there was no significant difference in TTD between SPS and sodium citrate anticoagulant. Although H. influenzae showed a remarkable difference in TTD between SPS (SA 14.8 h, SN 15.0 h) and sodium citrate (SA 23.5 h, SN 18.3 h), this difference was not statistically significant (P=0.10). CONCLUSION: Addition of blood enhanced growth of bacteria. All experimental bacteria except H. influenzae showed similar TTD in SPS blood and citrated blood. These results support the usefulness of sodium citrate anticoagulant for artificial inoculation in blood culture bottles.

In 1884 Robert Koch and Friedrich Loeffler published Koch's Postulates defining our historical understanding of the relationship between an organism and infection: one organism: one disease. In the last decade with research on the microbial community living on and in humans, a new concept of microbial diseases has emerged; that is, alterations of the microbial community can lead to disease including an extension beyond traditional "infectious" diseases to include metabolic disorders such as type 2 diabetes and obesity. As we continue to gain knowledge about the functions of the normal microbiome and the effects of alterations of the microbial population on disease pathogenesis, a new era of diagnostics and therapeutics will evolve.

Sepsis is a common and critical illness diagnosed via blood culture. Although a continuous blood culture monitoring system was introduced several decades ago, optimal utilization and improvement of blood culture methods has not been discussed recently. The author describes several blood culture-related topics including optimal blood collection procedures, quality control indicators, prior antibiotic treatment, delayed entry, time to detection, follow-up blood culture, catheter-related bloodstream infection, and new techniques to rapidly identify microorganisms. Although rapid, automatic blood culture systems are likely to be developed in the near future, quality improvement should be accomplished by well-educated medical personnel.

Psychrobacter sanguinis has been described as a Gram-negative, aerobic coccobacilli originally isolated from environments and seaweed samples. To date, 6 cases of P. sanguinis infection have been reported. A 53-year-old male was admitted with a generalized tonic seizure lasting for 1 minute with loss of consciousness and a mild fever of 37.8℃. A Gram stain revealed Gram-negative, small, and coccobacilli-shaped bacteria on blood culture. Automated microbiology analyzer identification using the BD BACTEC FX (BD Diagnostics, Germany) and VITEK2 (bioMérieux, France) systems indicated the presence of Methylobacterium spp., Aeromonas salmonicida, and the Moraxella group with low discrimination. The GenBank Basic Local Alignment Search Tool and an Ez-Taxon database search revealed that the 16S rRNA gene sequence of the isolate showed 99.30% and 99.88% homology to 859 base-pairs of the corresponding sequences of P. sanguinis, respectively (GenBank accession numbers JX501674.1 and HM212667.1). To the best of our knowledge, this is the first human case of P. sanguinis bacteremia in Korea. It is notable that we identified a case based on blood specimens that previously had been misidentified by a commercially automated identification analyzer. We utilized 16S rRNA gene sequencing as a secondary method for correctly identifying this microorganism.
Aeromonas salmonicida ; Bacteremia* ; Bacteria ; Databases, Nucleic Acid ; Discrimination (Psychology) ; Fever ; Genes, rRNA ; Humans ; Korea ; Male ; Methods ; Methylobacterium ; Middle Aged ; Moraxella ; Psychrobacter* ; RNA, Ribosomal, 16S ; Seaweed ; Seizures ; Unconsciousness

BACKGROUND: Multilocus sequence typing (MLST) is useful in determining the long-term evolutionary process and minimizes differences in experimental results across individuals and laboratories. It is also useful in determining evolutionary origins and backgrounds of bacterial species. This study carries out MLST analysis on VanA-type vancomycin-resistant Enterococcus faecium isolated from patient specimens in a single university hospital over nine years in order to observe changes in genetic evolution over time. METHODS: During the years from 2007 to 2015, 44 clinical isolates of vanA-containing E. faecium were collected from Ajou University Hospital in Korea. Species were identified by the VitekII system (bio-Merieux, USA), and antibiotic susceptibility testing was performed by disk diffusion and E-test according to Clinical and Laboratory Standards Institute (CLSI) guidelines. To determine genetic relatedness, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF M/S) was employed. To characterize clonal diversity, MLST analysis was used. RESULTS: All isolates were highly resistant to ampicillin, ciprofloxacin, and vancomycin but showed variable levels of resistance to teicoplanin. The 44 clinical isolates were genetically unrelated according to MALDI-TOF M/S analysis. MLST showed that the clinical isolates harbored 6 sequence types (ST), with ST17 (n=19) being the most common, followed by ST78 (n=13), ST192 (n=6), ST64 (n=4), ST262 (n=1), and ST414 (n=1). CONCLUSION: The MLST analysis showed that the sequence types of most isolates belonged to clonal complex 17 This is consistent with outbreaks in hospitals. We had single observations for ST262 and ST414, suggesting that they were random occurrences. MLST can be useful for speculating the genetic evolution of VanA-containing E. faecium isolates.
Ampicillin ; Ciprofloxacin ; Diffusion ; Disease Outbreaks ; Enterococcus faecium* ; Enterococcus* ; Evolution, Molecular ; Humans ; Korea ; Mass Spectrometry ; Multilocus Sequence Typing* ; Teicoplanin ; Vancomycin

BACKGROUND: The introduction of rotavirus vaccines has decreased the prevalence of rotavirus infections and might have changed the distribution of rotavirus genotypes. However, neonates are not eligible for vaccination and, therefore, are at risk for rotavirus infection while in the hospital nursery or neonatal intensive care unit. Our aim was to evaluate the shift of genotypes of group A rotavirus strains among neonates cared for in two geographically distant hospitals in Korea. METHODS: Analysis of rotavirus P and G genotypes was performed for 63 neonates (27 neonates in Seoul and 36 neonates in Busan) admitted to two hospitals between 2011 and 2013. RESULTS: Among the 63 tested neonates less than one month of age, 61 (96.8%) were infected with genotype G4P[6]. CONCLUSION: This study identified G4P[6] as the most frequently isolated genotypes among neonates in Korea; therefore, prevention of the G4P[6] genotype should be considered for neonates.
Genotype* ; Humans ; Infant, Newborn* ; Intensive Care, Neonatal ; Korea ; Nurseries ; Nurseries, Hospital ; Prevalence* ; Rotavirus Infections ; Rotavirus Vaccines ; Rotavirus* ; Seoul ; Vaccination

BACKGROUND: Candidemia has increased with an increasing number of people in the high risk group and so has become more important. This study was conducted to investigate the isolation rate of Candida species from candidemia patients and the change in rate of antifungal resistance. METHODS: At a single tertiary care hospital, 1,120 blood cultures positive for Candida species from 1997 to 2016 were investigated according to date of culture, gender, age, and hospital department. RESULTS: During the investigation period, the number of candidemia patients increased from 14 in 1997 to 84 in 2016. The most common organism identified during the two decades was Candida albicans (40.8%), followed by Candida parapsilosis (24.1%), Candida tropicalis (13.2%), and Candida glabrata (12.8%). C. glabrata was relatively common in females (45.5%) compared to males. The age group 40-89 years was more frequently infected than other age groups, and the most frequent isolates according to age group were C. albicans in neonate (66.7%), C. parapsilosis in 1-9-year-olds (41.7%), and C. glabrata in those aged ≥60 years (range; 13.3%–20.0%). According to the visited departments, C. albicans, C. glabrata, and Candida haemulonii were more common in medical departments, while C. parapsilosis was more common in surgical departments. In the antifungal susceptibility test, a rising trend of azole resistance among C. albicans and C. glabrata was observed in recent years. CONCLUSION: In this study, it was confirmed that the isolation rate of Candida species in blood is different by age, gender, and hospital department, and the distribution of isolated Candida species changed over time. The resistance patterns of antifungal agents are also changing, and continuous monitoring and proper selection of antifungal agents are necessary.
Antifungal Agents ; Candida albicans ; Candida glabrata ; Candida tropicalis ; Candida* ; Candidemia* ; Danazol ; Drug Resistance, Fungal* ; Female ; Hospital Departments ; Humans ; Infant, Newborn ; Male ; Prevalence* ; Tertiary Healthcare*