Donor-Derived Candida dubliniensis Resulting in Perigraft Abscesses in a Liver Transplant Recipient Proven by Whole Genome Sequencing: A Case Report.

BACKGROUND: The transmission of fungi via transplant, although well-known, has not often been molecularly proven. We describe a case of donor-derived candidiasis verified by whole genome sequencing. CASE DESCRIPTION: The multiorgan donor was a 42-year-old woman with subdural hemorrhage. Procurement of the thoracic organs was performed followed by the abdominal organs. Tissue from the left bronchus grew Candida dubliniensis. The liver recipient was a 63-year-old woman with cryptogenic liver cirrhosis. She was noted to have worsening leukocytosis on postoperative day (POD) 9. Computed tomography of the abdomen and pelvis showed multiple rim-enhancing collections around the graft. Percutaneous drainage was performed. Fluid cultures grew C dubliniensis. C dubliniensis isolated from the donor's left bronchus and the liver recipient's abscesses were verified to be related by whole genome sequencing. We postulate that C dubliniensis colonizing the donor's transected trachea could have contaminated the inferior vena cava when the former was left open after explant of the donor's lungs. A portion of the donor's contaminated inferior vena cava was transplanted along with the liver graft, resulting in the infected collections in the recipient. CONCLUSIONS: Our case report highlights the importance of maintaining a sterile field during organ procurement, especially in a multiorgan donor whose organs are explanted in succession.

NLRP3 inflammasome pathway has a critical role in the host immunity against clinically relevant Acinetobacter baumannii pulmonary infection.

The opportunistic Gram-negative bacterium Acinetobacter baumannii (AB) is a leading cause of life-threatening nosocomial pneumonia. Outbreaks of multidrug resistant (MDR)-AB belonging to international clones (ICs) I and II with limited treatment options are major global health threats. However, the pathogenesis mechanisms of various AB clonal groups are understudied. Although inflammation-associated interleukin-1ß (IL-1ß) levels and IL-1 receptor antagonist polymorphisms were previously implicated in MDR-AB-related pneumonia in patients, whether inflammasomes has any role in the host defense and/or pathogenesis of clinically relevant A. baumannii infection is unknown. Using a sublethal mouse pneumonia model, we demonstrate that an extensively drug-resistant clinical isolate (ICII) of A. baumannii exhibits reduced/delayed early pulmonary neutrophil recruitment, higher lung persistence, and, most importantly, elicits enhanced IL-1ß/IL-18 production and lung damage through NLRP3 inflammasome, in comparison with A. baumannii-type strain. A. baumannii infection-induced IL-1ß/IL-18 production is entirely dependent on NLRP3-ASC-caspase-1/caspase-11 pathway. Using Nlrp3-/- mice infection models, we further show that while NLRP3 inflammasome pathway contributes to host defense against A. baumannii clinical isolate, it is dispensable for protection against A. baumannii-type strain. Our study reveals a novel differential role for NLRP3 inflammasome pathway in the immunity against clinically relevant A. baumannii infections, and highlights inflammasome pathway as a potential immunomodulatory target.

A Case Report: Organs From a Donor With Highly Virulent Zoonotic Outbreak Strain of Streptococcus agalactiae Serotype III, Multilocus Sequence Type 283 Infective Endocarditis Did Not Result in Transmission With Adequate Prophylactic Antibiotic Cover.

In 2015, an outbreak involving a highly virulent zoonotic outbreak strain of Streptococcus agalactiae serotype III, multilocus sequence type 283 occurred in Singapore with increased neurologic complications, septic arthritis, and spinal infections in healthier patients. We report a case of a successful dual kidney transplant from a deceased donor with infective endocarditis and disseminated infection with the same strain of S agalactiae and we review the current literature.

Probing the magnetic profile of diluted magnetic semiconductors using polarized neutron reflectivity.

Room temperature ferromagnetism has been observed in the Cu doped ZnO films deposited under an oxygen partial pressure of 10-3 and 10-5 torr on Pt (200 nm)/Ti (45 nm)/Si (001) substrates using pulsed laser deposition. Due to the deposition at relatively high temperature (873 K), Cu and Ti atoms diffuse to the surface and interface, which significantly affects the magnetic properties. Depth sensitive polarized neutron reflectometry method provides the details of the composition and magnetization profiles and shows that an accumulation of Cu on the surface leads to an increase in the magnetization near the surface. Our results reveal that the presence of the copper at Zn sites induces ferromagnetism at room temperature, confirming intrinsic ferromagnetism.

Recurrent trichosporonosis with central nervous system involvement in an allogeneic hematopoietic stem cell transplant recipient.

Trichosporon is an ubiquitous yeast that has emerged as an opportunistic pathogen in the immunocompromised host. We describe a case of invasive trichosporonosis in an allogeneic hematopoietic stem cell transplant (allo-HSCT) recipient while on caspofungin antifungal prophylaxis. She developed disseminated trichosporonosis in the pre-engraftment period and was successfully treated with voriconazole. She later developed 2 further episodes of invasive trichosporonosis involving the central nervous system. This case highlights the challenges of managing trichosporonosis in allo-HSCT recipients and suggests the need for lifelong therapy in some patients.

Severe adenovirus pneumonia requiring extracorporeal membrane oxygenation support--Serotype 7 revisited.

INTRODUCTION: Adenovirus causing severe fatal pneumonia has been well described in infants, children, and patients with immunocompromised function, but reports in previously healthy adults are rare. We report 3 cases of severe adenovirus pneumonia in whom conventional mechanical ventilation failed and required extracorporeal membrane oxygenation support. METHODS: Retrospective case records review of 3 patients admitted to the medical intensive care unit, Singapore General Hospital, a tertiary care university-affiliated hospital, with severe adenovirus pneumonia requiring extracorporeal membrane oxygenation support from February to March 2013. RESULTS: All 3 patients were previously healthy immunocompetent adults from the community with negative HIV serology. Duration prior to development of respiratory failure requiring intubation and invasive mechanical ventilation was 2, 8 and 3 days. Veno-venous extracorporeal membrane oxygenation (ECMO) support as rescue ventilation was instituted in all 3 patients after 2, 16, and 5 days of conventional mechanical ventilator support. Duration on ECMO support was 16, 22, and 9 days and mechanical ventilation was 18, 62, and 19 days respectively. Length of stay in intensive care unit was 18, 68, and 21 days, and length of stay in hospital was 20, 70, and 31 days respectively. Two of the 3 patients died. CONCLUSION: The mainstay of treatment for patients with severe adenovirus pneumonia is still supportive, with the use of antivirals not apparently effective. Whilst ECMO support for rescue ventilation may be considered, the outcomes do not appear as promising as other viral pneumonias, mirroring that previously described in the paediatric population.

Acinetobacter calcoaceticus-Acinetobacter baumannii complex species in clinical specimens in Singapore.

This study was performed to determine the prevalence, distribution of specimen sources, and antimicrobial susceptibility of the Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) species complex in Singapore. One hundred and ninety-three non-replicate Acb species complex clinical isolates were collected from six hospitals over a 1-month period in 2006. Of these, 152 (78·7%) were identified as A. baumannii, 18 (9·3%) as 'Acinetobacter pittii' [genomic species (gen. sp.) 3], and 23 (11·9%) as 'Acinetobacter nosocomialis' (gen. sp. 13TU). Carbapenem resistance was highest in A. baumannii (72·4%), followed by A. pittii (38·9%), and A. nosocomialis (34·8%). Most carbapenem-resistant A. baumannii and A. nosocomialis possessed the bla(OXA-23-like) gene whereas carbapenem-resistant A. pittii possessed the bla(OXA-58-like) gene. Two imipenem-resistant strains (A. baumannii and A. pittii) had the bla(IMP-like) gene. Representatives of carbapenem-resistant A. baumannii were related to European clones I and II.

5 year analysis of bacteriology culture in a tropical burns ICU.

INTRODUCTION: Infection is a major cause of morbidity and mortality in burns patients. METHODOLOGY: A retrospective review of all 94 patients admitted to a regional burns ICU from 2004 to 2009 was performed. All the patients' data and records of all culture isolates from a computerized hospital wide database were studied. Epidemiology of the patients, bacteriology information including yield and correlation of bacteremia with positive cultures from other sites were examined. In addition, the relationship between burns excision surgeries to bacteremia was analyzed. RESULTS: 402 tissue cultures, 238 wound swab cultures, 269 endotracheal cultures, 125 urine cultures, 236 tip of monitoring line cultures and 474 blood cultures were studied. Acinetobacter baumannii was the most prevalent bacteria for all culture methods. Within 24 h of bacteremia, the tissue, line tips, endotracheal and wound swab cultures had yielded very similar pathogens (>70% of the time) to those from the blood stream. Furthermore 60% of all bacteremic episodes occur within 48 h of the surgery. CONCLUSION: In ICUs where multidrug resistant pathogens are endemic, the choice of appropriate antimicrobial empiric cover should be guided by the intensity of colonization with these organisms as indicated by the cultures from various sites.

Primary cutaneous cryptococcosis due to Cryptococcus gattii in Singapore.

Cryptococcosis is an invasive fungal infection that occurs worldwide. Infections caused by Cryptococcus (C.) neoformans are commonly associated with immunocompromised patients, while those caused by C. gattii predominantly affect immunocompetent hosts. However, the latter has also been increasingly reported in immunocompromised patients such as those with HIV. Cutaneous involvement by C. gattii in immunocompetent patients is a rare manifestation, with only a few cases reported worldwide. C. gattii infection has rarely been reported in Singapore, with all three reported cases presenting as meningitis in immunocompetent individuals. Its natural habitat is the Eucalyptus tree, which is common in Singapore. We report the case of a 37-year-old migrant worker who had primary cutaneous infection due to C. gattii after sustaining traumatic inoculation.

Correlation between the characteristic green emissions and specific defects of ZnO.

In this work, the correlation between the characteristic green emissions and specific defects of ZnO was investigated through a series of experiments that were designed to separate the subtle interplays among the various types of specific defects. With physical analysis and multimode Brownian oscillator modeling, the underlying mechanisms of the variant effects on green emission were revealed. The results demonstrate that the observed green emissions can be identified as two types of individual emissions, namely high energy and low energy, that are associated with specific defects and their locations. The surface modification that leads to downwards band bending was found to be responsible for the high-energy green emission. The relationship between the intensity of the low- energy green emission and the crystallographic lattice contraction indicates that oxygen vacancy is the dominant cause of such an emission that resides within the bulk of ZnO.

Chiral capillary electrophoresis with cationic pyrrolidinium-beta-cyclodextrin derivatives as chiral selectors.

New single-isomer, cationic beta-cyclodextrins, including mono-6-deoxy-6-pyrrolidine-beta-cyclodextrin chloride (pyCDCl), mono-6-deoxy-6-(N-methyl-pyrrolidine)-beta-cyclodextrin chloride (N-CH(3)-pyCDCl), mono-6-deoxy-6-(N-(2-hydroxyethyl)-pyrrolidine)-beta-cyclodextrin chloride (N-EtOH-pyCDCl), mono-6-deoxy-6-(2-hydroxymethyl-pyrrolidine)-beta-cyclodextrin chloride (2-MeOH-pyCDCl) were synthesized and used as chiral selectors in capillary electrophoresis for the enantioseparation of carboxylic and hydroxycarboxylic acids and dansyl amino acids. The unsubstituted pyCDCl exhibited the greatest resolving ability. Most analytes were resolved over a wide range of pH from 6.0 to 9.0 with this chiral selector. In general, increasing pH led to a decrease in resolution. The effective mobilities of all the analytes were found to decrease with increasing CD concentration. The optimal concentration for most carboxylic acids and dansyl amino acid was in the range 5-7.5 mM and >15 mM for hydroxycarboxylic acids. (1)H NMR experiments provided direct evidence of inclusion in the CD cavity.

Specific defects, surface band bending and characteristic green emissions of ZnO.

The green emission in ZnO can be identified as two characteristic emissions, namely high and low energy emissions, respectively. The study of band bending effect of ZnO surface demonstrates that oxygen vacancies cause both the core level and the valence band to shift to higher binding energy. The downward band bending induced by a strong accumulation layer, where the oxygen vacancies act as donors, results in the high energy green emission. ZnO with the low energy green emission has Zn 2p 3/2 core level binding energy shifted to lower binding energy. The depth of dominant oxygen vacancies plays an important role in determining the mechanisms of green emission.

Effect of femtosecond laser irradiation on structure of UV grade fused silica.

A p-polarized femtosecond laser beam was used to irradiate a UV grade fused silica to create microchannels, which are useful for producing optical gratings or micro fluidics devices. The laser irradiated surface was characterized using optical microscope, stylus profiler, SEM, XRD and TEM. A special technique was used to protect the laser irradiated surfaces in preparing cross-sectional TEM samples. The XRD spectra and TEM observation reveal that structure of the fused silica remain amorphous after the femtosecond laser irradiation.

Distribution of epstein-barr virus antigenic sites on the carboxyl terminal end of ribonucleotide reductase against nasopharyngeal carcinoma serum antibodies using an immunoabsorption method.

In an attempt to clone and express proteins from the Epstein-Barr virus (EBV) cDNA library to be used as antigens in an enzyme-linked immunosorbent assay (ELISA) format to test against the antibodies found in the sera of nasopharyngeal carcinoma (NPC) patients, we have isolated and characterized three clones. All three clones expressed the same polypeptides of different lengths, which belong to the carboxyl terminal end of the large subunit of ribonucleotide reductase (RR) of the EBV genome. All three clones were found to be immunogenic and could be used in an IgA and IgG ELISA against the NPC sera with various degrees of sensitivity and specificity. Because the clones varied in length, this difference provides a simple system to determine where most of the antibody epitopes lies on the protein. We designed an immunoabsorption assay and a mathematical model to help map the segment of the polypeptide most immunogenic to 43 NPC patients. Results were unexpected: 77% of the patients were most immunogenic to region z, which was the smallest fragment among the three fragments studied. Fragment z was only 33 amino acids in length. Only 14% and 19% of patients showed the most immunogenic region in segment x and y, respectively. This variation could be due to major histocompatibility complex antigens. The patients could be divided into three groups based on the immunoabsorption assays, in which each group responded to a different immunodominant segment in the RR antigen. The largest group responded to an immunodominant segment, which was only 33 amino acids long. This domain was coded for by the gene fragment from nucleotide 78,129 to nucleotide 78,227 of the EBV genome. This segment of the protein would be suitable for further epitope mapping studies.

Plasma renin and aldosterone in thyroid diseases.

The effect of thyroid hormones on the renin-angiotensin-aldosterone system has not been fully resolved. Highly specific immunoassays for measurement of renin, aldosterone, free T4 (fT4), free T3 (fT3) and ultrasensitive TSH enables a direct and more accurate measurement of these hormones. We investigated the relationship between plasma renin, aldosterone and thyroid hormones in the basal state and after intravenous frusemide. This is a cross-sectional study involving 37 patients with thyrotoxicosis, 42 rendered euthyroid with normal fT4, fT3 and TSH levels, 17 with euthyroid levels of fT4 and fT3 but suppressed TSH, and 11 with hypothyroidism. Basal plasma renin was significantly higher in thyrotoxicosis (63.4 +/- 9.8 microU/ml, mean +/- SEM) compared to euthyroid (32.7 +/- 4.4 microU/ml) and hypothyroid (26.7 +/- 9.8 microU/ml). Basal plasma renin for euthyroid with suppressed TSH (41.0 +/- 7.4 microU/ml) was significantly higher than hypothyroid (p = 0.02). Basal plasma aldosterones were not significantly different except for suppressed TSH (157.7 +/- 13 pg/ml), which was higher than normal (109.9 +/- 10.4 pg/ml; p = 0.04). Following frusemide, plasma renin and aldosterone were significantly increased in all groups. Plasma renin was highly correlated to fT3 (r = 0.405, p < 0.001), total T3 (r = 0.359, p < 0.001), fT4 (r = 0.331, p < 0.001) and TSH (r = 0.300, p < 0.001) in the basal state, but less to total T4 (r = 0.248, p < 0.01). Plasma renin correlated poorly to serum aldosterone (r = 0.212, p < 0.03). This study clearly showed that regulation of renin was mainly influenced by fT3, and that aldosterone response to frusemide was blunted in thyrotoxicosis despite normal electrolytes.

Levels of thyroxine, TSH, thyroid volume and mental performance among Orang Asli in selected settlements in Malaysia.

A significant difference in the levels of thyroxine (T4), thyroid stimulating hormone (TSH) and thyroid volume among settlements at various selected Orang Asli locations is reported. The levels improved according to the level of socio-economic development. No significant difference was found in mental performance by location.