Dongkyun Kim, Gyu Yel Hwang, Gilsung Yoo, Juwon Kim, Young Uh
Ann Clin Microbiol 2017 September, 20(3): 53-62. Published on 20 September 2017.
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.
[in Korean]
Jae-Seok Kim, Sung Mi Kim, Hyun Soo Kim
Ann Clin Microbiol 2017 September, 20(3): 63-66. Published on 20 September 2017.
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.
Joon Kim, Young Ihn Kwon, Wee Gyo Lee
Ann Clin Microbiol 2017 September, 20(3): 67-73. Published on 20 September 2017.
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 (bioMerieux, 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.
[in Korean]
Sangeun Lim, Hui-Jin Yu, Seungjun Lee, Eun-Jeong Joo, Joon-Sup Yeom, Hee-Yeon Woo, Hyosoon Park, Min-Jung Kwon
Ann Clin Microbiol 2017 September, 20(3): 74-79. Published on 20 September 2017.
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 37.8oC. 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 16SrRNA 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.
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