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The usefulness of bronchoalveolar lavage (BAL) fluid cellular analysis in non-human immunodeficiency virus (HIV)-infected patients with Pneumocystis jirovecii pneumonia (PCP) has not been adequately evaluated. The objective of this study was to analyze the cellular profiles of BAL fluid and to evaluate their prognostic significance in non-HIV-infected patients with PCP. A 7-year retrospective cohort study of 166 non-HIV-infected adult patients with PCP who underwent BAL was performed in a tertiary care hospital. The median total BAL fluid white blood cell count was 180/μl (interquartile range, 80 to 330) and was unaffected by the severity of PCP. The median percentages of BAL fluid neutrophils, lymphocytes, and alveolar macrophages were 13.1%, 31.7%, and 30.2%, respectively. The median percentage of BAL fluid neutrophils was significantly higher in severe than in mild-to-moderate PCP (20.4% versus 6.0%, P < 0.001), as was the absolute neutrophil count (24/μl versus 13/μl, P = 0.001). The percentage of BAL fluid neutrophils was an independent predictor of 30-day (adjusted odds ratio [aOR], 1.02; 95% confidence interval [CI], 1.01 to 1.03) and 60-day (aOR, 1.02; 95% CI, 1.01 to 1.04) mortalities. The 30-day and 60-day mortalities increased at rates of 15% ( P = 0.006) and 21% ( P < 0.001) per 10% increment of BAL fluid neutrophil levels, respectively. The degree of BAL fluid pleocytosis was relatively low without regard to the severity of PCP. The percentage of BAL fluid neutrophils can be used as a prognostic marker in non-HIV-infected patients with PCP.

A 52-year-old woman with relapsed acute lymphoblastic leukemia was diagnosed with Mycobacterium massiliense pneumonia after 4 months of chemotherapy. She developed M. massiliense bacteremia 1 month later. This is the first report of a proven case of M. massiliense bacteremia as a consequence of M. massiliense pneumonia.

A novel multiplex real-time PCR approach (Anyplex II RV16 [RV16]; Seegene, South Korea) was compared with a multiplex endpoint PCR kit (Seeplex RV15 ACE detection kit [RV15]; Seegene) and a liquid bead-based assay (xTAG respiratory viral panel [xTAG]; Abbott, United States). Of nasopharyngeal swabs or aspirates and bronchoalveolar lavage fluid samples submitted for RV15 testing, 199 retrospectively collected positive specimens and 283 prospectively collected specimens were further tested with RV16 and xTAG. A true-positive result was defined as a positive result from all three methods or RV16 and xTAG or RV15 and xTAG. For specimens with discrepant results, monoplex PCR and sequencing of the target viruses were performed. In total, 300 virus-positive specimens yielded 386 viruses. When the bocavirus results were excluded, the overall sensitivities of RV16, RV15, and xTAG were 95.2%, 93.3%, and 87.2%, respectively (95% confidence intervals, 93.0 to 97.4%, 90.8 to 95.8%, and 83.8 to 90.6%, respectively). RV16 was more sensitive than xTAG for coronavirus OC43/HKU1 (100% versus 26.1%; P < 0.0001) and adenovirus (100% versus 79.5%; P < 0.01) but was less sensitive than xTAG for rhinovirus/enterovirus (89.4% versus 97.9%; P < 0.05). RV16 demonstrated higher sensitivity than RV15 for the detection of adenovirus (100% versus 82.1%; P < 0.05). The specificities of all three methods ranged from 98.6% to 100%. Sequencing analysis of 64 rhinovirus-positive samples revealed that RV16 accurately differentiated between rhinovirus and enterovirus. RV16 most frequently missed rhinovirus C. In conclusion, the overall sensitivity of RV16 was better than that of xTAG. However, improvement of the sensitivity for rhinovirus is required.

In November 2010, NDM-1-producing Klebsiella pneumoniae (NDMKP) was identified for the first time in South Korea from four patients with no history of traveling abroad who stayed for 21 to 205 days in a tertiary care hospital. All were sequence type (ST) 340 and had nearly identical XbaI pulsed-field gel electrophoresis (PFGE) patterns. The bla NDM-1 -carrying plasmids were in the IncN group, with sizes ranging from 50 to 200 kb. These findings suggest that NDMKP had already been introduced into South Korea before this clustering was found.

Of 522 patients with Propionibacterium acnes bacteremia (PAB), 18 (3.5%) had clinically significant PAB. Of these 18 patients, 10 (55.6%) had hospital-acquired bacteremia and 6 (33.3%) had undergone invasive procedures before development of PAB. One patient with a ventricular septal defect presented with infective endocarditis. After the exclusion of 1 patient whose outcome was not available, the overall mortality rate was 5.9% (1/17).

We report the first nosocomial outbreak of human metapneumovirus (hMPV) infection in a pediatric patient population. Among 15 pediatric hMPV infections from March to May 2007, there was a nosocomial outbreak involving two patients sharing a room in a hemato-oncology ward with a patient with a community-acquired case of hMPV infection. The estimated incubation period was 7 to 9 days for a symptomatic nosocomial case. Sequencing of fusion genes of 15 isolates revealed two clusters belonging to subgroup A2 and one cluster belonging to subgroup B2. Three isolates from the outbreak had sequences identical to those of samples in the A2 cluster. There was also a separate nosocomial case represented by the B2 cluster.

Data on clinical isolates of Kodamaea ( Pichia ) ohmeri , an emerging fungal pathogen, are scarce. Over the past 5 years, we identified yeast isolates from nine patients with fungemia as K. ohmeri by using the API 20C system. Here, we reanalyzed these isolates first by sequencing the internal transcribed spacer 2 (ITS2) regions and then by growing the isolates on CHROMagar Candida medium and subjecting them to pulsed-field gel electrophoresis (PFGE). Based on their ITS2 sequences, six of the nine isolates were confirmed as K. ohmeri , while the others were identified as Candida haemulonii ( n = 2) and Candida parapsilosis ( n = 1). PFGE karyotyping of the K. ohmeri isolates revealed similar major bands, and their colonies showed a characteristic color change from pink to blue when grown on CHROMagar Candida medium for more than 48 h. For K. ohmeri , the ranges of MICs of fluconazole, voriconazole, caspofungin, and micafungin were 2 to 32 μg/ml, 0.03 to 0.5 μg/ml, 0.125 to 0.25 μg/ml, and 0.03 to 0.06 μg/ml, respectively. Restriction endonuclease analysis of genomic NotI-digested DNA (REAG-N) from isolates from different patients produced unique patterns, suggesting that the fungemia had occurred sporadically. This study determined that ITS2 sequence data, PFGE karyotypes, and CHROMagar Candida chromogenic culture medium are reliable diagnostic tools for identifying K. ohmeri while REAG-N is useful for genotyping the clinical isolates of K. ohmeri .

A nationwide surveillance study was undertaken to monitor antimicrobial resistance among clinical isolates of Streptococcus pneumoniae in Korea, with a special focus on vancomycin tolerance. For the 6-month period from March to August 2002, clinical isolates of S. pneumoniae were collected from 11 university hospitals and 1 reference laboratory. One-hundred eighty-eight isolates were measured for lysis rates after exposure to vancomycin for 4 h. Two vancomycin-tolerant S. pneumoniae (VTSP) strains, S3 and H8, were isolated from sputum cultures of two patients, who had stayed in intensive-care units of different hospitals with long-term antibiotic therapy and were not treated for pneumococcal pneumonia. The penicillin, cefotaxime, and vancomycin MICs for S3 were 8 μg/ml, >16 μg/ml, and 0.5 μg/ml, and those for H8 were 2 μg/ml, 2 μg/ml, and 0.5 μg/ml, respectively. While S3 belonged to serotype 23F and was autolysin defective, H8 belonged to serotype 13F and had intact autolysin. These strains were not clonally related as determined by pulsed-field gel electrophoresis of chromosomal DNA. In agreement with previous reports, both isolates showed pairing of TIGR4 vex2 with R6 pep27 and had two identical amino acid substitutions, Q441K in vncS and N25D in vex2 . These findings indicate that two VTSP strains have emerged independently in Korea, suggesting a prevalence rate of 1.1%. The emergence of VTSP would be a serious threat in Korea, where there are significant rates of penicillin resistance in S. pneumoniae . Monitoring of the prevalence of VTSP and further investigation of the clinical relevance of VTSP are warranted.

We assessed the accuracy of yeast bloodstream isolate identification performed over a 1-year period at 10 South Korean hospitals, using the matrix-assisted laser desorption ionization–time of flight (MALDI-TOF)-based Vitek MS system. The overall phenotypic misidentification rate was 3.4% (18/533), with considerable variation between hospitals (0.0% to 19.0%), compared to 1.1% (6/533) for the Vitek MS system.

We have previously shown that a thickened cell wall is responsible for the vancomycin resistance of vancomycin-resistant Staphylococcus aureus (VRSA) (equivalent to vancomycin-intermediate S. aureus and glycopeptide-intermediate S. aureus ) strain Mu50 (L. Cui, H. Murakami, K. Kuwahara-Arai, H. Hanaki, and K. Hiramatsu, Antimicrob. Agents Chemother. 44:2276-2285, 2000). However, the mechanism of vancomycin resistance in other VRSA strains remained unclear. In this study, 16 clinical VRSA strains from seven countries were subjected to serial daily passage in drug-free medium. After 10 to 84 days of passage in the nonselective medium, passage-derived strains with decreased MICs of vancomycin (MIC, −6 to 1.64 × 10 −3 . The data indicated that vancomycin-resistant cells are frequently generated from the passage-derived strains even after vancomycin selective pressure is lifted. Cell wall thicknesses and MICs of glycopeptides (vancomycin and teicoplanin) and beta-lactams (imipenem and oxacillin) were determined for a total of 48 strains, including 15 sets of three strains: the clinical VRSA strain, the passage-derived strain, and the vancomycin-resistant mutant strain obtained from the passage-derived strain. No simple correlation between glycopeptide and beta-lactam MICs was seen, while significant correlations between MICs of vancomycin and teicoplanin ( r = 0.679; P < 0.001) and between MICs of imipenem and oxacillin ( r = 0.787; P < 0.001) were recognized. Moreover, all of the VRSA strains had significantly thickened cell walls, which became thinner with the loss of vancomycin resistance during drug-free passages and again became thick in the resistant mutant strains. The data showed that cell wall thickness had high correlation with the MICs of the two glycopeptides (correlation coefficients, 0.908 for vancomycin and 0.655 for teicoplanin) but not with those of the beta-lactam antibiotics tested. These results together with coupled changes of cell wall thickness and vancomycin MICs in 16 isogenic sets of strains indicate that thickening of the cell wall is a common phenotype of clinical VRSA strains and may be a phenotypic determinant for vancomycin resistance in S. aureus.

Since vancomycin-intermediate Staphylococcus aureus (VISA) was first reported in Japan in 1997, there has been great concern that heterogeneous vancomycin-intermediate S. aureus (hetero-VISA) is the putative precursor of VISA. To investigate the prevalence, clinical significance, and molecular epidemiology of S. aureus with reduced susceptibility to vancomycin, all consecutive isolates of S. aureus isolated from clinical specimens from December 1998 to August 1999 at Asan Medical Center were screened for VISA and hetero-VISA by using brain heart infusion agar containing 4 μg of vancomycin/ml. Screen-positive isolates were confirmed by susceptibility testing and population analysis of subpopulations with reduced susceptibility to vancomycin. The isolates confirmed as hetero-VISA were typed by pulsed-field gel electrophoresis (PFGE). Medical records were reviewed to evaluate the clinical significance and risk factors for the acquisition of hetero-VISA. Of the 4,483 isolates that were tested, 53 were screen positive; no VISA was detected, but 24 isolates (0.54%) from 22 patients were hetero-VISA. All but two strains appeared to be clones of the Korean VISA strain, AMC11094, in the PFGE analysis. A total of 18 patients were in intensive care units, and 16 underwent major surgeries during the same admission. Only 10 of the 22 patients had previous methicillin-resistant S. aureus infections and 11 had previous vancomycin or teicoplanin therapy. Only 7 of the 22 patients from whom hetero-VISA strains were isolated were infected, and the remaining 15 patients were colonized. All seven infected patients were successfully treated with vancomycin. These results suggest that hetero-VISA can be treated with vancomycin, but the spread of hetero-VISA clonal to VISA is of concern, since many believe that VISA can arise from hetero-VISA, although this phenomenon was not observed in this study.

A differential time to positivity (DTP) of ≥120 min is useful for diagnosing catheter-related bacteremia, but data on diagnosing catheter-related candidemia (CRC) in this way are limited. We wished to evaluate the usefulness of the DTP for diagnosing CRC. All adult patients who had the same Candida species isolated from blood cultures drawn simultaneously from a central venous catheter (CVC) and a peripheral vein were included at a tertiary care hospital over an 18-month period. A total of 105 patients with candidemia who had positive simultaneous CVC and peripheral vein blood cultures were included in our study. Sixty-one patients (58%) had CRC (47 definite and 14 probable), and 38 (36%) had candidemia from another source (non-CRC). The remaining 6 patients (6%) with indeterminate candidemia were excluded from the final analysis. The overall sensitivity and specificity of a DTP of ≥120 min for diagnosing CRC were 85% (95% confidence interval [CI], 74% to 93%) and 82% (95% CI, 66% to 92%), respectively, and for neutropenic patients, they were 75% (95% CI, 19% to 99%) and 100% (95% CI, 75% to 100%), respectively. For Candida glabrata infections, the optimal DTP cutoff was ≥6 h, with a sensitivity of 63% (95% CI, 35% to 85%) and a specificity of 75% (95% CI, 35% to 97%). In summary, DTP is useful for diagnosing CRC, and a DTP of ≥120 min appears to be the optimal cutoff except for CRC caused by C. glabrata . For neutropenic patients, DTP may be useful as an adjunct test to rule in CRC and to decide whether a catheter should be removed.

We report a case of pyomyositis due to Mycobacterium haemophilum in a renal transplant recipient. M. haemophilum was identified by PCR-mediated sequence analysis of the heat shock protein gene in the DNA of the specimen. The patient was successfully treated with repeated surgical debridement and prolonged antimycobacterial therapy.

A multiplex real-time PCR assay that simultaneously detects the mecA , staphylococcal cassette chromosome (SCC mec )-open reading frame X ( orfX ) junction, and staphylococcal 16S rRNA genes was developed and evaluated using 444 staphylococcal strains. We demonstrated that this assay resulted in fewer false-positive results than a single-locus real-time PCR assay that amplified the SCC mec-orfX junction. This assay would be useful in a clinical laboratory in a region of high endemicity for methicillin-resistant Staphylococcus aureus (MRSA) infections.

The emerging fungal pathogens Candida haemulonii and Candida pseudohaemulonii often show high-level resistance to amphotericin B (AMB). We compared the utilities of five antifungal susceptibility testing methods, i.e., the Etest using Mueller-Hinton agar supplemented with glucose and methylene blue (Etest-MH), the Etest using RPMI agar supplemented with glucose (Etest-RPG), the Vitek-2 yeast susceptibility system, and the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution methods, for the detection of AMB-resistant isolates of C. haemulonii and closely related species. Thirty-eight clinical isolates (8 C. haemulonii , 10 C. pseudohaemulonii , and 20 Candida auris isolates) were analyzed. Of the 18 C. haemulonii and C. pseudohaemulonii isolates, 18, 15, 18, 10, and 9 exhibited AMB MICs of >1 μg/ml by the Etest-MH, Etest-RPG, Vitek-2, CLSI, and EUCAST methods, respectively. All 20 C. auris isolates showed AMB MICs of ≤1 μg/ml by all five methods. Of the methods, the Etest-MH generated the broadest distribution of AMB MICs for all 38 isolates and showed the best discrimination between the C. haemulonii and C. pseudohaemulonii isolates (4 to 32 μg/ml) and those of C. auris (0.125 to 0.5 μg/ml). Taking the Etest-MH as the reference method, the essential agreements (within two dilutions) for the Etest-RPG, Vitek-2, CLSI, and EUCAST methods were 84, 92, 55, and 55%, respectively; the categorical agreements were 92, 92, 79, and 76%, respectively. This study provides the first data on the efficacy of the Etest-MH and its excellent agreement with Vitek-2 for discriminating AMB-resistant from AMB-susceptible isolates of these Candida species.

Of 63 patients with Staphylococcus lugdunensis bacteremia, 15 (23.8%) had clinically significant bacteremia, with an incidence of 1.3 cases per 100,000 admissions. Of the five patients with community-acquired S. lugdunensis bacteremia, three had endocarditis. Catheters were the most common portal of entry for health-care-associated or hospital-acquired bacteremia. Only one patient died of bacteremia-related causes.

In this study, we investigated the rate of colonization of skin of children with atopic dermatitis (AD) by methicillin-resistant Staphylococcus aureus (MRSA) and characterized the isolates. Active skin lesions in pediatric AD patients were cultured with Rodac Staph (Komed, Korea). S. aureus isolates were examined for drug susceptibilities, analyzed for the eta , etb , tst , and pvl genes, and typed using agr polymorphism, pulsed-field gel electrophoresis of SmaI-restricted chromosomal DNA, and staphylococcal cassette chromosome mec (SCC mec ) typing. Eighty-seven (75.4%) of 115 patients had cultivable S. aureus isolates, 16 of which (18.3%) were MRSA. All MRSA isolates were susceptible to chloramphenicol, rifampin, cotrimoxazole, and ciprofloxacin. While methicillin-susceptible S. aureus (MSSA) isolates were composed of 23 isolates of singular types and nine clusters comprising 48 isolates, MRSA isolates were typed into three clones: eight isolates of pulsotype A- agr - 1 -SCC mec IV, five isolates of pulsotype B- agr - 3 -SCC mec IIb- etb positive, and three isolates of pulsotype C- agr - 3 -SCC mec IV. Three SCC mec IVA MRSA isolates were tst positive, but none were positive for the pvl or eta gene. Among 71 MSSA isolates, 7 isolates were tst positive, 6 of which were pulsotype F- agr - 3 , and 9 of 10 agr - 4 isolates were eta positive. The average ages of patients carrying MSSA, SCC mec IVA MRSA, and SCC mec IIb MRSA were 7.7 ± 4.6, 3.1 ± 1.5, and 8.2 ± 3.1 years, respectively. Among the patients carrying MRSA, two patients had been treated with oral antimicrobials, and one had been admitted to the hospital 18 months previously. In conclusion, community-acquired MRSA isolates of a few clones colonized the skin of patients with AD without risk factors for the acquisition of hospital-acquired MRSA, which suggested that the skin of children with AD may represent a significant reservoir of MRSA colonization in the community.