A Perspective of the Wearing-off Phenomenon in a Patient with Parkinson’s Disease: A Case Report / 대한연하장애학회지

Dysphagia is a major disability in patients with Parkinson’s disease. Unlike typical motor symptoms, dysphagia is relatively unresponsive to dopaminergic drugs. However, occasionally, swallowing difficulties are much improved by dopaminergic agonists and significantly affected by on/off periods. In such cases, it is difficult to assess the severity of dysphagia accurately if swallowing function evaluation is performed without considering the wearing-off phenomenon in patients with PD. Here, we report a case of dysphagia in a female patient with Parkinson’s disease that was severely affected by the wearing-off phenomenon in response to prolonged use of levodopa. The patient presented with severe oral phase delay with choking symptoms during fluid intake. A videofluoroscopic swallow study performed during an ‘off-period’ showed massive aspiration with severely impaired swallowing function.However, when swallowing evaluation was performed during the ‘on-period’, almost no abnormal function was observed. After adopting an on/off period-tailored diet prescription, sufficient nutrition was possible without aspiration. Consideration of the wearing-off phenomenon is essential when evaluating swallowing function in patients with Parkinson’s disease. Patient-specific swallowing evaluations and diet prescriptions are needed to establish optimal therapeutic strategies.

Pneumonia due to Schizophyllum commune in a Patient with Acute Myeloid Leukemia: Case Report and Literature Review

Schizophyllum commune is a mold in phylum Basidiomycota and is an uncommon human pathogen. Sinusitis and allergic bronchopulmonary mycosis are the two major diseases caused by S. commune. Although there have been several reports of invasive fungal diseases, most of them were invasive sinusitis. We present a case of invasive fungal pneumonia due to S. commune, developed in a patient with acute myeloid leukemia presenting neutropenic fever. The diagnosis was made by characteristic macroscopic and microscopic findings of fungal isolate and was confirmed via sequencing of internal transcribed spacer region. The patient was improved after 8 weeks of antifungal therapy based on the susceptibility result.We propose that S. commune should be considered as an emerging pathogen of invasive fungal pneumonia when a patient is under immunocompromised state. We also reviewed global literatures focused on the invasive fungal diseases caused by S. commune

Evaluation of a Newly Developed Rapid Automated Fluorescent Lateral Flow Immunoassay to Detect IgG and IgM Antibodies to Chikungunya Virus

The ichroma Chikungunya virus (CHIKV) IgG/IgM (Boditech Med Inc., Chuncheon, Korea) is a newly developed rapid lateral flow immunoassay for detection of anti- CHIKV-IgG/ IgM. This study conducted with thirty-six anti-CHIKV IgG positive sera, 57 anti-CHIKV IgM positive sera and 163 anti-CHIKV IgG/IgM negative sera which were confirmed by commercial enzyme-linked immunosorbent assays (ELISAs) (Inbios CHIKjj Detect™ IgM Capture ELISA, Inbios CHIKjj Detect™ IgG ELISA (InBios International Inc., Seattle, WA, USA), Anti-CHIKV ELISA (IgM), Anti- CHIKV ELISA (IgG) (Euroimmun, Lübeck, Germany)). The ichroma detected all 36 anti-CHIKV IgG and 57 anti-CHIKV IgM positivity (100% sensitivity). For 163 anti-CHIKV IgG/IgM negative sera, the ichroma showed one false positive for IgM (99.4% specificity). The ichroma showed no cross-reactivity and no interference. The ichroma demonstrated good diagnostic performance compared to the current ELISAs.

Evaluation of a Newly Developed Rapid Automated Fluorescent Lateral Flow Immunoassay to Detect IgG and IgM Antibodies to Chikungunya Virus

The ichroma Chikungunya virus (CHIKV) IgG/IgM (Boditech Med Inc., Chuncheon, Korea) is a newly developed rapid lateral flow immunoassay for detection of anti- CHIKV-IgG/ IgM. This study conducted with thirty-six anti-CHIKV IgG positive sera, 57 anti-CHIKV IgM positive sera and 163 anti-CHIKV IgG/IgM negative sera which were confirmed by commercial enzyme-linked immunosorbent assays (ELISAs) (Inbios CHIKjj Detect™ IgM Capture ELISA, Inbios CHIKjj Detect™ IgG ELISA (InBios International Inc., Seattle, WA, USA), Anti-CHIKV ELISA (IgM), Anti- CHIKV ELISA (IgG) (Euroimmun, Lübeck, Germany)). The ichroma detected all 36 anti-CHIKV IgG and 57 anti-CHIKV IgM positivity (100% sensitivity). For 163 anti-CHIKV IgG/IgM negative sera, the ichroma showed one false positive for IgM (99.4% specificity). The ichroma showed no cross-reactivity and no interference. The ichroma demonstrated good diagnostic performance compared to the current ELISAs.

Effect of needle type on intravascular injection in transforaminal epidural injection: a meta-analysis

BACKGROUND: Lumbosacral transforaminal epidural injection (TFEI) is an effective treatment for spinal disease. However, TFEI may have several types of complications, some of which can be attributed to intravascular injection. We reviewed studies to compare the intravascular injection rate among different needle types. METHODS: We searched the literature for articles on the intravascular injection rate among different needle types used in TFEI. The search was performed using PubMed, MEDLINE, the Cochrane Library, EMBASE, and Web of Science. RESULTS: A total of six studies comprising 2359 patients were identified. Compared with the Quincke needle, the Whitacre needle reduced the intravascular injection rate (OR = 0.57, 95% CI = [0.44–0.73], P < 0.001). However, compared with the Quincke needle, the Chiba needle did not reduce the intravascular injection rate (OR = 0.80, 95% CI = [0.44–1.45], P = 0.46). In one study, the intravascular injection rate using a blunt-tip needle was lower than that using a sharp needle. In another study, the Whitacre and the blunt-tip needle have similar intravascular injection rates, while, the catheter-extension needle showed a reduced intravascular injection rate. CONCLUSIONS: This meta-analysis showed that the Whitacre needle reduced the intravascular injection rate as compared with the Quincke needle, but failed to establish that the Chiba needle can decrease the intravascular injection rate in TFEI. Moreover, the blunt-tip needle can reduce the intravascular injection rate compared with the Quincke needle, and the catheter-extension needle can reduce the intravascular injection rate compared with the Whitacre and the blunt-tip needle.

Comparison of Six Commercial Diagnostic Tests for the Detection of Dengue Virus Non-Structural-1 Antigen and IgM/IgG Antibodies

ELISAs and rapid diagnostic tests (RDTs) are widely used for diagnosing dengue virus (DENV) infection. Using 138 single blood samples, we compared the ability to detect non-structural (NS)-1 antigen and anti-DENV IgM/IgG antibodies among (1) DENV Detect NS1 ELISA, DENV Detect IgM capture ELISA and DENV Detect IgG ELISA (InBios International, Inc.); (2) Anti-Dengue virus IgM Human ELISA and Anti-Dengue virus IgG Human ELISA (Abcam); (3) Dengue virus NS1 ELISA, Anti-Dengue virus ELISA (IgM) and Anti-Dengue virus ELISA (IgG) (Euroimmun); (4) Asan Easy Test Dengue NS1 Ag 100 and Asan Easy Test Dengue IgG/IgM (Asan Pharm); (5) SD BIOLINE Dengue Duo (Standard Diagnostics); and (6) Ichroma Dengue NS1 and Ichroma Dengue IgG/IgM (Boditech Med). For NS1 antigen detection, InBios and Euroimmun showed higher sensitivities (100%) than the RDTs (42.9–64.3%). All tests demonstrated variable sensitivities for IgM (38.1–90.5%) and IgG (65.7–100.0%). InBios and Boditech Med demonstrated higher sensitivity (95.6% and 88.2%, respectively) than the other tests for combined NS1 antigen and IgM antibody. Five NS1 antigen tests had good agreement (92.8–98.6%) without showing positivity for chikungunya. However, all IgG tests demonstrated potential false-positivity with variable ranges. Clinical laboratories should note performance variations across tests and potential cross-reactivity.

Development and implementation of standardized method for detecting immunogenicity of acellular pertussis vaccines in Korea

PURPOSE: There is no standard method for confirming the immunogenicity of acellular pertussis vaccines. We tried to develop a local standard method for evaluating the immunogenicity of the three-component of acellular pertussis vaccines which was developed by a Korean local company. MATERIALS AND METHODS: The developed pertussis antigens (pertussis toxin, filamentous hemagglutinin, pertactin) were evaluated by in-house enzyme-linked immunosorbent assay (ELISA) using 189 negative sera, 25 positive sera, and 73 paired sera (pre- and post-Tdap [tetanus, diphtheria, and acellular pertussis] vaccinated sera). ELISA units were calculated by the reference line method, compared with World Health Organization reference sera, and the cut-off value was calculated using negative sera. RESULTS: When compared to National Institute for Biological Standards and Control control antigen (NIBSC) control antigens, the developed pertussis toxin (PT) and filamentous haemagglutinin (FHA) antigens were 203.48 and 61.60 IU/µg, respectively. Each in-house ELISA was established by validating the coefficients of variation % (PT, 11.53%; FHA, 8.60%; pertactin [PRN], 9.86%) obtained from the results of inter- and intra-assay variation. Also, the cut-off values of PT, FHA, and PRN were 11.65, 38.95, and 5.66 EU/mL, respectively. The distributions of antibody levels in paired showed that 93.15% (68/73) in anti-PT IgG, 97.26% (72/73) in anti-FHA IgG, and 100% in anti-PRN IgG were higher than a 100% increase after vaccination. Additionally, the values of 89.04% (65/73) in anti-PT IgG, 97.26% (72/73) in anti-FHA IgG, and 100% in anti-PRN IgG were below each cut-off point. CONCLUSION: We established an in-house ELISA method using self-developed antigens, and these immunoassays have provided a way to standardize measuring the immunogenicity of newly developed vaccines, through single- and dual-serology.

Establishment of Experimental Murine Peritonitis Model with Hog Gastric Mucin for Carbapenem-Resistant Gram-Negative Bacteria

Animal models are essential to studies of infectious diseases. The use of mice to test bacterial infection has been extensively reported. However, methods applied to clinical isolates, particularly for carbapenem-resistant bacteria, must be tailored according to the infection models and bacteria used. In this study, we infected 6-week-old female BALB/c mice intraperitoneally with different strains of resistant bacteria plus 3% hog gastric mucin. This method was found to be efficient and readily applicable for investigation of carbapenem-resisant Gram-negative pathogens (e.g., Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) detected in Korea.

A Case of Spontaneous Bacterial Peritonitis with Bacteremia Caused by Shewanella algae

Human infection caused by Shewanella algae is rare, which usually occurred after direct contact with seawater or ingestion of raw seafood in the immunocompromised host. There have been anecdotal reports about Shewanella infections in human, but their pathogenic role and microbiologic data are limited. Here, we report a fatal case of spontaneous bacterial peritonitis with bacteremia due to S. algae in a 57-year-old male with liver cirrhosis who had no history of exposure to seawater or raw seafood. Polymicrobial infection with Streptococcus mitis and Escherichia coli was combined and the patient died in spite of early appropriate antimicrobial therapy and early goal-directed therapy for sepsis.

Clinical Impact of Cytochrome P450 2C19 Genotype on the Treatment of Invasive Aspergillosis under Routine Therapeutic Drug Monitoring of Voriconazole in a Korean Population

BACKGROUND: Genetic polymorphisms of cytochrome P450 enzymes, especially CYP2C19 influence voriconazole pharmacokinetics. However, the impact of CYP2C19 genetic polymorphisms on the therapeutic efficacy and toxicity of voriconazole therapy are not well established. MATERIALS AND METHODS: In this prospective observational study, we analyzed all consecutive adult patients with hematologic diseases who were treated for invasive aspergillosis (IA) with voriconazole between January 2011 and June 2012. CYP2C19 genotype and routine therapeutic drug monitoring of voriconazole were performed. The target range for voriconazole trough levels was 1-5.5 mg/L. RESULTS: A total of 104 consecutive patients were enrolled, including 39 homozygous extensive metabolizers (EMs, 38%), 50 heterozygous extensive metabolizers (HEMs, 48%), and 15 poor metabolizers (PMs, 14%). The initial voriconazole trough levels were 1.8, 2.7, and 3.2 mg/L in EMs, HEMs, and PMs, respectively (P = 0.068). Out-of-range initial trough levels were most frequently observed in EMs (46%) followed by HEMs (26%) and PMs (0%) (P = 0.001). The frequency of initial trough levels 5.5 mg/L differed significantly among the 3 groups (P = 0.005). However, treatment response, all-cause and IA-attributable mortality, and the occurrence of voriconazole-related adverse events did not differ significantly among the 3 groups (P = 0.399, P = 0.412, P = 0.317, and P = 0.518, respectively). CONCLUSIONS: While none of the initial voriconazole trough levels in PMs was outside the target range, subtherapeutic initial trough levels were frequent in EMs. Although there was no significant relationship between CYP2C19 genotype and either the clinical outcomes of IA or toxicity of voriconazole, further large-scale multicenter studies using clinical data from homogeneous populations are required.

Surgical outcomes for robot-assisted laparoscopic myomectomy compared with laparoscopic myomectomy / 대한산부인과내시경학회지

OBJECTIVE: To compare surgical outcomes of patients with myoma after robot-assisted laparoscopic myomectomy and laparoscopic myomectomy. METHODS: Retrospective chart review of 15 robot-assisted laparoscopic myomectomy (RLM) patients and 30 laparoscopic myomectomy (LM) patients at Jeju National University Hospital in Jeju between July 2009 and July 2012. Clinical features and surgical outcomes were compared. RESULTS: Surgical time was longer among RLM patinets (185.7 min vs 114.4 min). Patients undergoing robot-assisted myomectomy had a bigger size of the largest myoma, and bigger average size of the myomas. When adjusted for myoma size and number, no significant differences were noted between robotic (RLM: 24.5 min/cm) vs laparoscopic (LM: 21.5 min/cm) groups for mean operating time/total diameter. Blood loss (1.7 g/dl vs 1.95 g/dl), transfusion (0% vs 6.6%) were both no significant differences between the robotic and laparoscopic groups. CONCLUSION: When adjusted for myoma size and number, short-term outcomes were similar after robotic and laparoscopic myomectomy. Robot-assisted myomectomy is considered reliable procedure.

Molecular Epidemiologic Analysis of Community-Onset Extended Spectrum Beta-Lactamase (ESBL) Producing Escherichia coli Using Infrequent-Restriction-Site Polymerase Chain Reaction (IRS-PCR) with Comparison by Pulsed-Field Gel Electrophoresis (PFGE)

BACKGROUND: We evaluated the ability of infrequent restriction site-polymerase chain reaction (IRS-PCR) to perform molecular epidemiologic analysis of Community-Onset Extended Spectrum Beta-Lactamase (ESBL) producing Escherichia coli, and also assessed the use of PFGE as an alternative method. MATERIALS AND METHODS: IRS-PCR assay was performed using combinations of adaptors for XbaI and HhaI restriction sites on clinical isolates of E. coli (n=51). We compared the discriminatory power, quality and efficiency of IRS-PCR to PFGE. RESULTS: In E. coli, PFGE discriminated 39 (76.4%) and IRS-PCR discerned 41 (80.3%) of the total 51 strains. It took much less time to complete IRS-PCR (one day) than PFGE (at least 4 days). CONCLUSIONS: IRS-PCR is a more sensitive and rapid alternative to PFGE for molecular epidemiologic analysis of E. coli.

Real-Time Nucleic Acid Sequence-Based Amplification to Predict the Clinical Outcome of Invasive Aspergillosis

Monitoring the response to therapy for invasive aspergillosis (IA) is essential for the management of patients with hematologic diseases. We evaluated the correlation between the outcome of real-time nucleic acid sequence-based amplification (RTi-NASBA) for Aspergillus 18S rRNA and the clinical outcome of IA. A total of 157 serum samples from 29 patients with IA were tested for RTi-NASBA. The treatment response and mortality were compared with the NASBA outcome (whether the NASBA value was converted to negative or not) at 12 weeks after the start of antifungal therapy. At 12 weeks, there was a moderate correlation between the treatment failure and persistently positive NASBA (kappa = 0.482; P = 0.019). Deaths attributable to IA were more prevalent in patients without negative conversion of NASBA than in those with negative conversion (50% vs 5%; P = 0.013). Significant factors of treatment failure at 12 weeks were the status of hematologic disease (nonremission; P = 0.041) and the NASBA outcome (failure of negative conversion; P = 0.024). Survival was significantly better in patients with negative conversion of NASBA than those with persistently positive values (P = 0.036). This study suggests that the serial monitoring of RTi-NASBA could be useful for prediction of the clinical outcome in hematologic patients with IA.

Application of Infrequent-Restriction-Site Polymerase Reaction (IRS-PCR) to the Molecular Epidemiologic Analysis of Methicillin Resistant Staphylococcus aureus (MRSA)

BACKGROUND: We investigated the usefulness of infrequent-restriction-site polymerase chain reaction (IRS-PCR) compared with pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) on the molecular epidemiologic analysis of methicillin-resistant Staphylococcus aureus (MRSA). MATERIALS AND METHODS: We used fifty clinical isolates of MRSA collected from 10 university hospitals located in Seoul. We performed three procedures on these isolates: PFGE using SmaI, IRS-PCR using XbaI-Hha I or EagI-Hha I, and MLST using seven house-keeping genes. We determined the clusters of molecular types by dendrogram using the unweighted pair group method with arithmetic mean (UPGMA) and Dice coefficients. RESULTS: MLST analysis showed that isolates exhibited ST1, ST5, ST72, ST89, and ST239. In PFGE, the isolates clustered into 5 major groups with 80% similarity, which subsequently became classified into 18 subgroups with 95% similarity. In IRS-PCR using EagI-HhaI restriction enzymes, there was little resolution among the patterns of isolates. However, XbaI-HhaI IRS-PCR showed 5 groups with a 90% similarity. These groups were then classified into 9 subgroups with a 95% similarity. There were no significant differences among the isolates from different hospitals. CONCLUSIONS: The XbaI-HhaI IRS-PCR method could be a useful tool in the molecular epidemiology of MRSA. Its resolution power was good enough to analyze isolates, because the patterns of IRS-PCR were closely correlated with those of MLST and showed diverse groups.

Efficacy of Vancomycin against Staphylococcus aureus according to Inoculum Size in a Neutropenic Mouse Infection Model

BACKGROUND: Staphylococcus aureus is one of the most important gram-positive pathogens in many clinical situations. Use of vancomycin against methicillin resistant S aureus (MRSA) has been anecdotally associated with treatment failure, which could be attributable to an inoculum effect (IE). Using a neutropenic mouse thigh infection model, we tried to evaluate the in vivo IE of vancomycin against S. aureus. MATERIALS AND METHODS: Twenty strains of S aureus were used. Minimum inhibitory concentrations (MICs) were determined by the Clinical and Laboratory Standards Institute guideline. Six-week-old specific-pathogen-free, female CD-1 mice weighing 23-27 grams were used. The neutropenic mice received inoculations of 5.02-5.74 log10 CFU/thigh in one thigh (low inoculum, LI), and 7.22-7.73 log10 CFU/thigh in the other thigh (high inoculum, HI) before therapy. The mice were treated with 6 hourly subcutaneous doses of vancomycin (3.125-100 mg/kg) for 24 h. Single-dose serum pharmacokinetics of vancomycin was determined. Dose-response data were analyzed by an Emax model using non-linear regression. Static doses and area under the curve (AUC)/MIC for bacteriostatic effect at each inoculum were calculated and compared. The ratio of static dose and AUC/MIC between HI and LI (IE index) provided the magnitude of IE for each organism. RESULTS: Five methicillin-susceptible S aureus (MSSA) strains and 15 MRSA strains were used. Vancomycin MICs of the 20 strains varied by 4-fold (0.5-2 mg/L). The AUC/MIC ratio was the major parameter determining the efficacy of vancomycin against S aureus . Mean (range) static dose on LI and HI was 20.7 (11.8-35.1) and 136.7 (32.1-314), respectively. The mean IE index of static dose between them was 7.39. Mean (range) of AUC/MIC on LI and HI was 27.0 (6.61-66.6) and 152.3 (46.2-344), respectively, which produced a mean IE index of AUC/MIC of 7.47. The IE indices of the MSSA strains were significantly higher than those of the MRSA strains (11.3 vs. 6.1 on static dose [P=0.018], 11.4 vs. 6.2 on AUC/MIC [P=0.034]). CONCLUSIONS: With a 100-fold inoculum increment of S aureus , at least a 7-fold dose of vancomycin would be required to show the same bacteriostatic effect. Thus, IE as well as MICs is an important parameter in selecting and adjusting a dose and dosage interval along with the resistance profile in the treatment of S. aureus infections. IE to vancomycin observed in the in vivo neutropenic mouse model was more evident for MSSA strains than for MRSA strains.

Molecular Epidemiologic Analysis of Methicillin-Resistant Staphylococcus aureus Isolates from Bacteremia and Nasal Colonization at 10 Intensive Care Units: Multicenter Prospective Study in Korea

We investigated molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolated at 10 intensive care units (ICUs) in Korea. MRSA isolates from bacteremia and nasal colonization were collected prospectively from October 2008 through May 2009 at 10 University-affiliated hospital ICUs. A total of 83 and 175 MRSA strains were isolated from bacteremia and nasal colonization, respectively. Acquired group accounted for 69.9% (n = 58) of bacteremia and 73.1% (n = 128) of nasal colonization. Pulsed-field gel electrophoresis (PFGE) type B (SCCmec type II/ST5) was dominant in the acquired group followed by PFGE type D (SCCmec type IVA/ST72; a community genotype). Seven of 58 (12.1%) acquired bacteremia and 15 of 128 (11.8%) acquired nasal colonizations had SCCmec type IVA/ST72 genotype, which indicated that the community genotype had already emerged as a cause of ICU acquired MRSA infection or colonization. Antibiotic resistance rates to ciprofloxacin, tetracycline, clindamycin and trimethoprim/sulfamethoxazole were 84.4%, 67.1%, 78.1%, and 12.0%, respectively. Susceptibility to ciprofloxacin best predicted a community genotype (sensitivity 96.5%; specificity 96.9%; odds ratio 861; 95% confidence interval 169-4,390, P < 0.001) and the positive predictive value was 90.2%. Among 23 nasal re-colonized strains, 7 MRSA strains (30.4%) were different from the originally colonized strains on the basis of PFGE types.

Effects of Peroxisome Proliferator-Activated Receptor-gamma on the Production of Tumor Necrosis Factor-alpha in Stimulated Human Monocoytes

BACKGROUND: We evaluated the effects of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) on the production of tumor necrosis factor-alpha (TNF-alpha) and expression of nuclear factor-kappaB (NF-kappaB) in stimulated THP-1 cells, a human monocyte cell line. MATERIALS AND METHODS: We evaluated the cytotoxic effect of 15-Deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), one of natural PPAR-gamma ligands, using commercial cell proliferation assay. Cells were pretreated with 15d-PGJ(2) and then stimulated with lipopolysaccharide (LPS) or lipoteichoic acid (LTA). The amount of TNF-alpha was measured by using commercial ELISA method. NF-kappaB activation was evaluated by Western blot analysis. RESULTS: 15d-PGJ(2) showed dose-dependent cytotoxic effect on the tested cells after 4 hr of treatment. Stimulation of cells by LPS or LTA induced TNF-alpha production. TNF-alpha production was markedly decreased in the cells pretreated with 15d-PGJ(2) compared to cells treated only with LPS or LTA in a dose-dependent manner. Pretreatment of 15d-PGJ(2) reduced LPS or LTA induced NF-kappaB expression in the nuclear extracts of THP-1 cells. CONCLUSION: 15d-PGJ(2) pretreatment decreased TNF-alpha production from the THP-1 cells stimulated by LPS or LTA, and this assumed to be associated with inhibition of NF-kappaB activation.

Once-Daily Gentamicin Administration for Community-Associated Methicillin Resistant Staphylococcus aureus in an in vitro Pharmacodynamic Model: Preliminary Reports for the Advantages for Optimizing Pharmacodynamic Index

PURPOSE: Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) infections are increasing. Although gentamicin (GEN) is usually susceptible against CA-MRSA, GEN is rarely considered for treatment as monotherapy. We employed an in vitro pharmacodynamic model (IVPDM) to compare efficacies of GEN against CA-MRSA with two dosing regimens [thrice-daily (TD), once-daily (OD)]. MATERIALS AND METHODS: Using two strains of CA-MRSA, we adopted IVPDM comprised of two-compartments with a surface-to-volume ratio of 5.34 cm-1. GEN regimens were simulated with human pharmacokinetic data of TD and OD. Experiments were performed over 48 hours in triplicate for each strain and dosing regimen. RESULTS: MICs of GEN for YSSA1 and YSSA15 were 1 and 2 mg/L, respectively. In OD, indices of peak/MIC were > 8.6 at least, in contrast to or = 3-log10 reduction in CFU/mL was demonstrated prior to 4 hours in TD and OD, and continued until 8 hours for both strains. However, reductions in the colony counts at 24 and 48 hours were significantly larger for OD compared to TD in both strains (p < 0.001). During TD, resistance developed in YSSA1 and small colony variants (SCVs) were documented in YSSA15. No resistance or SCVs were observed during OD in both strains. CONCLUSION: TD and OD showed the same killing slopes until 8 hours. After the 24 hours of experiments, OD of GEN would be advantageous not only in having more reductions in colony counts, but also suppressing the development of resistance or SCVs for 48 hours.

A Case of Primary Infective Endocarditis Caused by Community-Associated Methicillin-Resistant Staphylococcus aureus in a Healthy Individual and Colonization in the Family

Primary community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) endocarditis has rarely been reported in healthy individuals without risk factors, such as skin and soft tissue infections, and intravenous drug abuse. We describe a case of infective endocarditis by CA-MRSA (ST72-PVL negative-SCCmec IVA) in previously healthy individuals with no underlying medical condition and CA-MRSA colonization in the family.

A Case of Perianal Abscess due to Panton-Valentine Leukocidin Positive Community-Associated Methicillin-Resistant Staphylococcus aureus : Report in Korea and Literature Review from the Far East

Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) with Panton-Valentine leukocidin (PVL) genes have recently emerged worldwide, but infections due to PVL carrying CA-MRSA strains have never been reported in Korea. We report a case of extensive perianal abscess due to PVL+ CA-MRSA in a 76-year-old Korean female patient, of which genetic background was very close to USA300. It belonged to staphylococcal cassette chromosome mec element (SCCmec) type IV, ST8 of multilocus sequence typing (MLST), type 1 spa type, and accessory gene regulator locus (agr) group I. Comprehensive literature reviews from the Far East showed molecular characteristics were diverse and PVL genes were infrequently found than in western countries.