Jae-Seok Kim, Tae-Jung Sung, Hong Kyu Park, Ji Young Park, Hyoun Chan Cho, Il Tae Hwang, Hae-Ran Lee
Ann Clin Microbiol 2014 September, 17(3): 73-79. Published on 20 September 2014.
Background: The intestinal microflora varies according to the factors such as age, diet and environment. It is debated whether the changes of microbiota after birth are associated with atopic disease. The purpose of this study was to investigate colonization rates of some intestinal microflora during the initial 9 months after birth, and their association with the development of atopy.
Methods: Stool specimens were collected at 1, 3, 7 days and at 1, 2, 4, 6, 9 months after birth, and Escherichia coli, Lactobacillus, Bifidobacterium, Staphylococcus aureus were cultured with selective media. Diagnosis for atopy was accomplished via clinical history of atopy, serum total IgE, and skin prick test.
Results: By 12 months of age, among 48 infants, 36 (75.0%) were non-atopic while 12 (25.0%) had developed atopy. Although not statistically significant, the intestinal microflora of infants with atopy vs. non-atopy was characterized by being less often colonized with E. coli (12.5% vs. 52.4%; P=0.093) and S. aureus (0% vs. 38.1%; P=0.066) at three days after birth. Colonization rates of E. coli reached 50% after 3 days of birth in non-atopy group whereas this rate was not achieved until after 1 month in the atopy group.
Conclusion: The intestinal colonization rates of bacteria in this study were not statistically different between atopy and non-atopy groups. Rapid colonization of E. coli and S. aureus was observed within 1 week after birth in the non-atopy group. The exact association between atopy and the bacterial colonization and/or diversity in the early days after birth has yet to be determined.
[in Korean]
Chang-Ki Kim, Byung Soo Lee, Myung Joon Choi, Hee Jin Kim, Kyungwon Lee
Ann Clin Microbiol 2014 September, 17(3): 80-85. Published on 20 September 2014.
Background: Fluoroquinolones (FQs) are important drugs for treating multidrug-resistant tuberculosis (MDR-TB). However, due to widespread use of FQs, the resistance rates to FQs have been increasing among Mycobacterium tuberculosis. Rapid and reliable FQ drug susceptibility testing (DST) is crucial for successful treatment of MDR-TB. In this study, the feasibility of molecular detection of FQ resistance was evaluated.
Methods: A total of 95 MDR-TB isolates were collected from Jan through Oct 2009 at the Korean Institute of Tuberculosis. DST for ofloxacin (OFL), levofloxacin, and moxifloxacin was performed using the Lowenstein-Jensen media absolute concentration method. Minimum inhibitory concentrations (MIC) of these were determined using the broth microdilution method. DNA was extracted from cultured isolates using bead beating method. The quinolone resistance-determining region (QRDR) of gyrA and gyrB were amplified and those sequences were analyzed.
Results: Of 95 isolates, 79 were resistant to at least one of FQs. Of these, 71 (89.9%) harbored mutation in the QRDR of gyrA or gyrB. None of FQ susceptible strains possessed any mutation in gyrA or gyrB. Mutations in codon 94 of gyrA were most common; only two isolates had mutation in only the gyrB gene. OFL MICs for isolates with gyrA mutation ranged from 1 to 32 μg/mL, but FQ susceptible isolates showed MICs ranging from ≤0.06 to 0.5 μg/mL.
Conclusion: Mutation analysis of QRDR of gyrA and gyrB showed 89.9% sensitivity and 100% specificity for detecting FQ resistance in MDR-TB. Therefore, molecular DST can be useful for rapid detection of FQ resistance in MDR-TB.
[in Korean]
Soo Jin Yoo, Jeong-U Han, Bo-Moon Shin
Ann Clin Microbiol 2014 September, 17(3): 86-90. Published on 20 September 2014.
Multiplex PCR of nasopharyngeal aspirates detected viruses and atypical bacteria in 75.3% (219/291) of infants with acute respiratory infections from July 2010 to June 2013. Frequent viruses were human rhinovirus (29.9%), parainfluenza virus (21.7%), respiratory syncytial virus (17.9%), and human metapneumovirus (10.3%). Mycoplasma pneumoniae and Bordetella pertussis were detected in 3.4% and 0.3%, respectively.
[in Korean]
Bo Ra Son, Kyeong Seob Shin
Ann Clin Microbiol 2014 September, 17(3): 91-94. Published on 20 September 2014.
Toxic shock syndrome is an acute and febrile illness that rapidly progress to shock and multi-organ failure, and it is caused by toxin-producing strains of Staphylococcus aureus or Streptococcus species. Streptococcal toxic shock syndrome (STSS) is usually caused by group A streptococci, but non-group A STSS is rare. In this study, we describe a case of STSS caused by Streptococcus agalactiae (group B streptococci) in a patient with alcoholic liver cirrhosis. At arrival in our hospital, the patient had a decreased mental status with hemorrhagic bullae on four extremities, and he progressed to a fatal outcome within 4 days in spite of antibiotic treatment.
[in Korean]
Yu Jung Jung, Hee Jae Huh, Chang-Seok Ki, Nam Yong Lee
Ann Clin Microbiol 2014 September, 17(3): 95-98. Published on 20 September 2014.
Brevibacterium spp. are Gram-positive, irregularly rod-shaped, strictly aerobic bacteria that resemble corynebacteria. Since they are a part of normal skin flora, they have been regarded as apathogenic, and human infections related to them are very rare. A 46-year-old man previously diagnosed with diffuse large B-cell lymphoma presented with fever without a definitive infectious source. Blood cultures from both peripheral blood and a central venous catheter showed that only aerobic bottles grew contaminants, while anaerobic bottles did not. Although the automated microbial identification system indicated Propionibacterium acnes, the isolated species was identified as B. casei by 16S rRNA sequence analysis. Our case emphasizes the utilization of 16S rRNA sequence analysis when the result from an automated system does not correspond with other laboratory findings. This is the first case of catheter-related blood stream infection due to B. casei identified by 16S rRNA sequence analysis.
Kye-Hyung Kim, Namhee Kim, Kyung-Hwa Shin, Shine Young Kim, Chulhun L. Chang, Jongyoun Yi
Ann Clin Microbiol 2014 September, 17(3): 99-103. Published on 20 September 2014.
Aggregatibacter aphrophilus, a normal component of oral cavity flora, mostly causes infective endocarditis and only rarely causes spondylitis; no spondylitis cases have been previously reported in Korea. We report a case of pyogenic spondylitis due to A. aphrophilus without endocarditis. A 64-year-old man was admitted for back pain lasting 3 weeks. There was severe tenderness on lumbar spines but no fever. Laboratory evaluation showed leukocytosis and elevated C-reactive protein. Blood cultures were negative. Magnetic resonance imaging showed psoas abscess and vertebral inflammation. Pus was obtained by computerized tomography-guided aspiration from the psoas abscess and inoculated into blood culture bottles. After 5 days of incubation, growth was detected: the isolate was a Gram-negative short rod bacteria identified as A. aphrophilus by the automated system; this was confirmed by 16S ribosomal RNA sequencing. There was no evidence of endocarditis in echocardiography and retinal examination. Back pain persisted despite 8 weeks of antibiotic treatment, so vertebral corpectomy was performed. A. aphrophilus, a rare cause of pyogenic spondylitis, can induce spondylitis without endocarditis. If a patient with pyogenic spondylitis shows negative routine bacterial cultures, fastidious organisms such as A. aphrophilus should be suspected and the blood culture bottles could be used.
[in Korean]
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