Does duration of cryostorage affect survival rate, pregnancy, and neonatal outcomes? Large-scale single-center study of slush nitrogen (SN2 ) vitrified-warmed blastocysts.

OBJECTIVE: To evaluate the effects of the duration of cryostorage on clinical outcomes after embryo transfer of vitrified blastocysts stored in an open-device slush-nitrogen (SN2 ) system. METHODS: A retrospective cohort study was carried out on 1632 autologous vitrified-warmed blastocyst transfer cycles between January 2013 and June 2014. Duration of cryostorage was divided into four groups: Group I: 0-6 months (n=937); Group II: 7-12 months (n=299); Group III: 13-24 months (n=165); and Group IV: ≥25 months (n=231). The effects of the duration of cryostorage on the survival rate (SR), clinical pregnancy rate (CPR), live birth rate (LBR), and neonatal outcomes of vitrified blastocysts stored in an open-device SN2 system were evaluated. RESULTS: There were no significant differences between groups in SR, CPR, LBR, and neonatal outcomes after autologous vitrified-warmed blastocyst transfer. Multivariate logistic regression analysis showed no effect on LBR from duration of cryostorage. CONCLUSION: Vitrification using SN2 and long-term cryostorage in an open-device system are safe and effective and do not significantly affect clinical outcomes after embryo transfer.

Fungal arthritis with adjacent osteomyelitis caused by Candida pelliculosa: a case report.

BACKGROUND: Candida sp. osteoarticular infection is rare and most often due to hematogenous seeding during an episode of candidemia in immunocompromised patients. However, the diagnosis can be delayed in patients with subtle symptoms and signs of joint infection without a concurrent episode of candidemia. CASE PRESENTATION: A 75-year-old woman presented with a three-year history of pain and swelling of the left knee. Candida pelliculosa was detected from the intraoperative tissue when the patient had undergone left total knee arthroplasty 32 months ago, but no antifungal treatment was performed. One year after the total knee arthroplasty, C. pelliculosa was repeatedly isolated from the left knee synovial fluid and antifungal treatment comprising amphotericin B deoxycholate and fluconazole was administered. However, joint infection had extended to the adjacent bone and led to progressive joint destruction. The patient underwent surgery for prosthesis removal and received prolonged antifungal treatment with micafungin and fluconazole. CONCLUSIONS: This case shows that C. pelliculosa, an extremely rare non-Candida albicans sp., can cause fungal arthritis and lead to irreversible joint destruction owing to delayed diagnosis and treatment.

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.

Comparative evaluation of a newly developed 13-valent pneumococcal conjugate vaccine in a mouse model.

Animal models facilitate evaluation of vaccine efficacy at relatively low cost. This study was a comparative evaluation of the immunogenicity and protective efficacy of a new 13-valent pneumococcal conjugate vaccine (PCV13) with a control vaccine in a mouse model. After vaccination, anti-capsular antibody levels were evaluated by pneumococcal polysaccharide (PnP) enzyme-linked immunosorbent assay (ELISA) and opsonophagocytic killing assay (OPA). Also, mice were challenged intraperitoneally with 100-fold of the 50% lethal dose of Streptococcus pneumoniae. The anti-capsular IgG levels against serotypes 1, 4, 7F, 14, 18C, 19A, and 19F were high (quartile 2 >1,600), while those against the other serotypes were low (Q2 ≤ 800). Also, the OPA titres were similar to those determined by PnP ELISA. Comparative analysis between new PCV13 and control vaccination group in a mouse model exhibited significant differences in serological immunity of a few serotypes and the range of anti-capsular IgG in the population. Challenge of wild-type or neutropenic mice with serotypes 3, 5, 6A, 6B, and 9V showed protective immunity despite of induced relatively low levels of anti-capsular antibodies. With comparison analysis, a mouse model should be adequate for evaluating serological efficacy and difference in the population level as preclinical trial.

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.

Genetic diversity of the ftsI gene in ß-lactamase-nonproducing ampicillin-resistant and ß-lactamase-producing amoxicillin-/clavulanic acid-resistant nasopharyngeal Haemophilus influenzae strains isolated from children in South Korea.

Haemophilus influenzae frequently colonizes the nasopharynx of children and adults, which can lead to a variety of infections. We investigated H. influenzae carriage in the nasopharynx of 360 children, in terms of (1) the prevalence of strains with decreased susceptibility, and (2) the presence of amino acid substitutions in PBP3. One hundred twenty-three strains were isolated (34.2%, 123/360), 122 of which were classified as nontypable H. influenzae (NTHi). Of these, ß-lactamase-nonproducing ampicillin-susceptible strains accounted for 26.2%, ß-lactamase-producing-ampicillin-resistant strains for 9.0%, ß-lactamase-nonproducing ampicillin-resistant (BLNAR) strains for 40.2%, and ß-lactamase-producing amoxicillin-/clavulanic acid-resistant (BLPACR) for 24.6%, respectively. Pulsed field gel electrophoresis (PFGE) patterns were so diverse that they were clustered into 41 groups. The amino acid substitutions in the transpeptidase domain (292 amino acids) of ftsI in BLNAR isolates showed that group IIb accounted for 30.6%, IIc for 8.2%, IId for 16.3%, III for 32.7%, and the others for 12.2%. Moreover, groups IIb (56.7%; 17/30) and III (23.3%; 7/30) were prevalent among BLPACR strains. They were subclassified into more diverse sequence subtypes by analysis of the entire PBP3 (610 amino acids). Groups IIb, IIc, IId, and III exhibited 13, four, six, and four sequence subtypes, respectively. Such a genetic diversity is likely indicative of significant potential for decreased antimicrobial susceptibility in nasopharyngeal-colonizing NTHi strains.

Molecular epidemiology of extended-spectrum ß-lactamase-producing Escherichia coli in the community and hospital in Korea: emergence of ST131 producing CTX-M-15.

BACKGROUND: The prevalence of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli has been increased not only in the hospital but also in the community worldwide. This study was aimed to characterize ESBL- producing E. coli isolates and to investigate the molecular epidemiology of community isolates in comparison with hospital isolates at a single center in Korea. METHODS: A total of 142 ESBL-producing E. coli isolates were collected at Daejeon St Mary's Hospital in Korea from January 2008 to September 2009. The ESBLs were characterized by PCR sequencing using specific primers. The genetic relatedness was determined by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). RESULTS: Of 142 isolates, 139 were positive for CTX-M type ESBLs; CTX-M-14 (n = 69, 49.6 %), CTX-M-15 (n = 53, 38.1 %) and both CTX-M-14 and -15 (n = 17, 12.2 %). CTX-M-14 and CTX-M-15 were detected in both community and hospital isolates whereas isolates producing both CTX-M14 and-15 were mainly identified in the hospital. CTX-M producing E. coli isolates were genetically heterogeneous, revealing 75 distinct PFGE types. By MLST, 21 distinctive STs including 5 major STs (ST131, ST405, ST38, ST10, and ST648) were identified. Major STs were distributed in both community and hospital isolates, and ST131 was the predominant clone regardless of the locations of acquisition. No specific major STs were confined to a single type of ESBLs. However, ST131 clones were significantly associated with CTX-M-15 and the majority of them were multidrug-resistant. Distinctively, we identified a hospital epidemic caused by the dissemination of an epidemic strain, ST131-PFGE type 10, characterized by multidrug resistance and co-producing both CTX-Ms with OXA-1 or TEM-1b. CONCLUSIONS: The epidemiology of ESBL-producing E. coli is a complex and evolving phenomenon attributed to the horizontal transfer of genetic elements and clonal spread of major clones, predominantly ST131. The multidrug resistant ST131 clone producing CTX-M-15 has emerged as a major clone in both the community and hospital, suggesting the widespread of this epidemic clone in Korea.

Downregulation of RNAIII in vancomycin-intermediate Staphylococcus aureus strains regardless of the presence of agr mutation.

Reduced vancomycin susceptibility in Staphylococcus aureus can cause serious problems relating to treatment failure and persistent infection. We investigated vancomycin susceptibility, genetic relationships and transcriptional changes of the accessory gene regulator (agr) in vancomycin-intermediate S. aureus (VISA) strains isolated from South Korea compared with vancomycin-susceptible S. aureus (VSSA) strains. Molecular characterization, population analysis profiling, agr sequencing and transcriptional profiling of RNAIII by real-time RT-PCR were performed. Of 16 VISA strains tested, eight exhibited ST5, agr II and type II SCCmec. The others exhibited ST239, agr I and type III SCCmec. A point mutation in AgrA (Asp8Gly or Ile238Lys) was found in only five VISA strains; no mutations were detected in the other strains. However, RNAIII levels markedly decreased in all VISA strains (mean of 1.39-fold change) compared with the VSSA strains (31.51-fold change) in late-exponential phases (P<0.0001). The downregulation of RNAIII could be an important genetic event in the VISA strains, regardless of the presence or absence of the agr mutation.

Molecular epidemiology of vancomycin-resistant Enterococcus faecium bloodstream infections among patients with neutropenia over a 6-year period in South Korea.

Over a 6-year period (March 2000-February 2006), there were 60 vancomycin-resistant Enterococcus faecium (VREF) bloodstream infections (BSIs) in a hematology unit, accounting for 83.3% of all VREF BSIs in the hospital. We investigated 49 VREF isolates causing BSIs in patients with neutropenia to understand the molecular epidemiology at this unit. All isolates had the vanA genotype. Pulsed-field gel electrophoresis typing revealed high clonal diversity (23 types with nine clusters comprising 35 isolates) and 1 predominant type, type A (14/49, 28.6%), persisted at this unit throughout the study period, suggesting the clonal spread of this endemic strain by cross-contamination. Tn1546 types were less heterogeneous, with five main Tn1546 types, two of which (types I and IV) accounted for 67.4% of isolates. This indicates that in addition to clonal spread, the horizontal transfer of Tn1546 played a major role in the nosocomial dissemination of vancomycin resistance. The genetic diversity of VREF increased over time, implying an increasing influx of new strains into the unit and genetic changes, possibly attributable to the horizontal transfer of diverse Tn1546 types. Despite such diversity, all the isolates belonged to clonal complex 17, which is the epidemic clone worldwide, enriched with the esp (35/49, 71.4%) and hyl (24/49, 48.9%) virulence genes. This hospital-adapted clone has become endemic and is well suited to causing BSIs in patients with neutropenia in this unit.

Fidgetin-like 1 gene inhibited by basic fibroblast growth factor regulates the proliferation and differentiation of osteoblasts.

UNLABELLED: The FIGNL1 gene was proven to be a new subfamily member of ATPases associated with diverse cellular activities (AAA proteins). In this in vitro study, the AAA proteins inhibited osteoblast proliferation and stimulated osteoblast differentiation. We showed that FIGNL1 may play some regulatory role in osteoblastogenesis. INTRODUCTION: The fidgetin-like 1 (FIGNL1) gene encodes a new subfamily member of ATPases associated with diverse cellular activities (AAA proteins). Although the FIGNL1 protein localizes to both the nucleus and cytoplasm, the function of FIGNL1 remains unknown. In a previous study, we identified several genes that mediate the anabolic effects of basic fibroblast growth factor (bFGF) on bone by using microarray data. FIGNL1 was one of the genes that downregulated >2-fold in MC3T3-E1 cells after treatment with bFGF. Therefore, this study was aimed to identify and confirm the function of FIGNL1 on osteoblastogenesis. MATERIALS AND METHODS: We examined the effect of the FIGNL1 gene on proliferation, differentiation, and apoptosis in mouse osteoblast cells (MC3T3-E1 and mouse primary calvarial cells) using flow cytometry, RT-PCR, cell proliferation assay, and cell death assay. MC3T3-E1 cells and mouse calvarial cells were transfected with small interfering RNA (siRNA) directed against the FIGNL1 or nontargeting control siRNA and examined by cell proliferation and cell death assays. Also, FIGNL1 was fused to enhance green fluorescent protein (EGFP), and the EGFP-fused protein was transiently expressed in MC3T3-E1 cells. RESULTS: Reduced expression of FIGNL1 by bFGF and TGF-beta1 treatment was verified by RT-PCR analysis. Overexpression of FIGNL1 reduced the proliferation of MC3T3-E1 and calvarial cells, more than the mock transfected control cells did. In contrast, siFIGNL1 transfection significantly increased the proliferation of osteoblasts, whereas overexpression of FIGNL1 did not seem to alter apoptosis in osteoblasts. Meanwhile, overexpression of FIGNL1 enhanced the mRNA expression of alkaline phosphatase (ALP) and osteocalcin (OCN) in osteoblasts. In contrast, siFIGNL1 decreased the expression of ALP and OCN. A pEGFP-FIGNL1 transfected into MCT3-E1 cells had an initially ubiquitous distribution and rapidly translocated to the nucleus 1 h after bFGF treatment. CONCLUSIONS: From these results, we proposed that FIGNL1, a subfamily member of the AAA family of proteins, might play some regulatory role in osteoblast proliferation and differentiation. Further analyses of FIGNL1 will be needed to better delineate the mechanisms contributing to the inhibition of proliferation and stimulation of osteoblast differentiation.