Multicenter Evaluation of the Implementation Status of Laboratory Tests in Korea and the Potential Usefulness of a Multiplex PCR Assay in Patients with Suspected Central Nervous System Infections.

BACKGROUND: The rapid diagnosis and treatment of central nervous system (CNS) infections are critical to minimizing morbidity and mortality. We evaluated the implementation status of laboratory tests in patients with suspected CNS infection, and the potential usefulness of a multiplex PCR assay for rapid and simultaneous detection in cerebrospinal fluid (CSF) of 14 targets capable of causing CNS infections. METHODS: The study was conducted at 5 hospitals located in Daegu and Gyeongju over a period of 6 months. A total of 140 patients with suspected CNS infection were included. CSF samples were tested for 6 bacteria, 7 viruses, and 1 yeast using multiplex PCR (FilmArray Meningitis/Encephalitis Panel, BioFire Diagnostics/Biomerieux, Salt Lake City, UT, USA) and conventional diagnostic testing including chemistry tests, cell count, bacterial culture, antigen detection assay, and pathogen-specific PCR. RESULTS: The five conventional tests most commonly performed were the chemistry and cell count (100%), bacterial culture (94.3%), enterovirus PCR (52.9%), and herpes simplex virus PCR (25.7%). Among the 140 CSF samples, 27 (19.3%) and 42 (30.0%) tested positive by conventional and the FilmArray ME panel testing, respectively. CONCLUSIONS: The detection rate of pathogens for CNS infections increased using only one FilmArray test compared to all of the conventional methods actually performed in patients with suspected CNS infection.

Serotype Distribution and Antimicrobial Resistance of Invasive and Noninvasive Streptococcus pneumoniae Isolates in Korea between 2014 and 2016.

BACKGROUND: Several factors contribute to differences in Streptococcus pneumoniae serotype distribution. We investigated the serotype distribution and antimicrobial resistance of S. pneumoniae isolated between 2014 and 2016 in Korea. METHODS: We collected a total of 1,855 S. pneumoniae isolates from 44 hospitals between May 2014 and May 2016, and analyzed the serotypes by sequential multiplex PCR. We investigated the distribution of each serotype by patient age, source of the clinical specimen, and antimicrobial resistance pattern. RESULTS: The most common serotypes were 11A (10.1%), followed by 19A (8.8%), 3 (8.5%), 34 (8.1%), 23A (7.3%), and 35B (6.2%). The major invasive serotypes were 3 (12.6%), 19A (7.8%), 34 (7.8%), 10A (6.8%), and 11A (6.8%). Serotypes 10A, 15B, 19A, and 12F were more common in patients ≤5 years old, while serotype 3 was more common in patients ≥65 years old compared with the other age groups. The coverage rates of pneumococcal conjugate vaccine (PCV)7, PCV10, PCV13, and pneumococcal polysaccharide vaccine 23 were 11.8%, 12.12%, 33.3%, and 53.6%, respectively. Of the 1,855 isolates, 857 (46.2%) were multi-drug resistant (MDR), with serotypes 11A and 19A predominant among the MDR strains. The resistance rates against penicillin, cefotaxime, and levofloxacin were 22.8%, 12.5%, and 9.4%, respectively. CONCLUSIONS: There were significant changes in the major S. pneumoniae serotypes in the community. Non-PCV13 serotypes increased in patients ≤5 years old following the introduction of national immunization programs with the 10- and 13-polyvalent vaccines.

Gastric cancer detection using gastric juice pepsinogen and melanoma-associated gene RNA.

OBJECTIVES: To develop a new method for gastric cancer detection with gastric juice using melanoma-associated gene (MAGE) RNA and pepsinogen (PG). METHODS: In total, 183 gastric juice and paired serum specimens were obtained from 134 patients with gastric cancer and 49 healthy individuals. The gastric juice specimens were analyzed with MAGE A1 to A6 nested reverse transcription-polymerase chain reaction. The serum and gastric juice PG were measured with a PG I and II immunoassay. RESULTS: The gastric juice PG I and PG I/II ratios were more accurate than those of serum. The combination test using the gastric PG I/II ratio and MAGE was the most accurate, with a sensitivity of 77.6% and a specificity of 87.8%. The sensitivity was 78.8% for stage I gastric cancer and not influenced by cancer location or pathologic type. CONCLUSIONS: The combination test is potentially an additional tool for gastric cancer detection.

MAGE A1-A6 RT-PCR and MAGE A3 and p16 methylation analysis in induced sputum from patients with lung cancer and non-malignant lung diseases.

The melanoma antigen gene (MAGE) A1-A6 RT-PCR system was developed for the detection of lung cancer cells in the sputum. However, we identified MAGE expression in some patients with non-malignant lung diseases. To understand these patterns of MAGE expression, we performed MAGE A3 methylation-specific PCR (MSP) and p16 MSP. We collected 24 biopsy specimens of lung cancer tissue and performed MAGE A1-A6 RT-PCR, MAGE A3 MSP and p16 MSP. RNA and DNA were simultaneously extracted from induced sputum specimens of 133 patients with lung diseases and 30 random sputum specimens of healthy individuals and the 3 molecular analyses were performed. The patients were diagnosed as 65 cases of lung cancer and 68 of benign lung diseases. Positive rates of MAGE A1-A6 RT-PCR, MAGE A3 MSP and p16 MSP were as follows: in lung cancer tissue, 87.5, 58.3 and 70.8%; in the sputum of lung cancer patients, 50.8, 46.2 and 63.1%; benign lung diseases, 10.3, 30.9 and 39.7%; and healthy individuals, 3.3, 6.7 and 3.3%. Of the 40 MAGE-positive cases, 33 were diagnosed with lung cancer and 7 as having benign lung diseases. From the 7 cases of MAGE-positive benign lung diseases, 6 cases showed methylation abnormalities. The MAGE-positive group revealed significantly higher rates of methylation abnormalities. Of the 40 MAGE-positive cases, 39 cases were found to be lung cancer or benign lung diseases with abnormal methylation. Thus, MAGE expression in the sputum suggests the presence of lung cancer cells or pre-cancerous cells.