bluuebunny/crossref_metadata_2025 huggingface dataset:
The proteolysis adaptor, NblA, is essential for degradation of the core pigment of the cyanobacterial light‐harvesting complex
Authors: Sendersky Eleonora , Kozer Noga , Levi Mali , Moizik Michael , Garini Yuval , Shav‐Tal Yaron , Schwarz Rakefet
Published: July 2015

The cyanobacterial light‐harvesting complex, the phycobilisome, is degraded under nutrient limitation, allowing the cell to adjust light absorbance to its metabolic capacity. This large light‐harvesting antenna comprises a core complex of the pigment allophycocyanin, and rod‐shaped pigment assemblies emanating from the core. NblA, a low‐molecular‐weight protein, is essential for degradation of the phycobilisome. NblA mutants exhibit high absorbance of rod pigments under conditions that generally elicit phycobilisome degradation, implicating NblA in degradation of these pigments. However, the vast abundance of rod pigments and the substantial overlap between the absorbance spectra of rod and core pigments has made it difficult to directly associate NblA with proteolysis of the phycobilisome core. Furthermore, lack of allophycocyanin degradation in an NblA mutant may reflect a requirement for rod degradation preceding core degradation, and does not prove direct involvement of NblA in proteolysis of the core pigment. Therefore, in this study, we used a mutant lacking phycocyanin, the rod pigment of Synechococcus elongatusPCC7942, to examine whether NblA is required for allophycocyanin degradation. We demonstrate that NblA is essential for degradation of the core complex of the phycobilisome. Furthermore, fluorescence lifetime imaging microscopy provided in situ evidence for the interaction of NblA with allophycocyanin, and indicated that NblA interacts with allophycocyanin complexes that are associated with the photosynthetic membranes. Based on these data, as well as previous observations indicating interaction of NblA with phycobilisomes attached to the photosynthetic membranes, we suggest a model for sequential phycobilisome disassembly by NblA.
‘Capitalist tools in socialist hands’? China Mobile in global financial networks
Authors: Wójcik Dariusz , Camilleri James
Published: July 2015

The paper analyses the evolution of China Mobile – one of China's pioneer ‘national champions’, and one of the world's largest telecom companies – through the lens of global financial networks, focusing on the role of advanced business services, financial centres and offshore jurisdictions in economic development. It demonstrates that despite being a domestic company, China Mobile is plugged firmly into the global financial networks, with incorporation in Hong Kong, cross‐listing in Hong Kong and New York, and opaque offshore companies registered in the British Virgin Islands. Global advanced business services firms, with Goldman Sachs in the lead, have been instrumental in the very conception of China Mobile in 1997 and its subsequent expansion, thus helping the Chinese government consolidate and modernise the whole telecom sector. The study highlights the position of Hong Kong as an onshore‐offshore financial centre intermediating between global financial markets and mainland China, and underwriting the reputation of China's ‘national champions’. The analysis also points to the advantages of Beijing over Shanghai as a command centre of state‐owned and controlled enterprises, acting as a magnet for advanced business services. The relevance of global financial networks to China, a latecomer on the stage of financial globalisation, highlights the scope for applying the concept to the rest of the world, and its potential contribution to economic geography.
A population‐based study on blood lead levels in blood donors
Authors: Delage Gilles , Gingras Suzanne , Rhainds Marc
Published: July 2015

BACKGROUND

Recent studies suggested that blood transfusion may represent a significant source of lead exposure in premature infants. Objectives of this study were to determine blood lead levels (BLLs) in a representative sample of blood donors and to identify risk factors associated with BLLs of 0.15 µmol/L or more.

STUDY DESIGN AND METHODS

A study was conducted in 2006 to 2007 in 49 drive sites in Quebec. Individuals who qualified for blood donation were eligible to participate. Information was harvested from blood donor file and a standardized self‐administered questionnaire. Lead analysis was performed by inductively coupled plasma mass spectrometry. Data on Quebec blood donors from 2003 to 2006 (n = 320,543) were used to establish a reference population. Geometric mean (GM) and 95% confidence interval (CI) were used to describe the results. The project was approved by an ethics committee.

RESULTS

Of 6715 eligible individuals, 3490 participated (1392 women and 2098 men). Their mean age was 46.5 years. Results were weighted for region, sex, and age. The GM of BLLs was 0.082 µmol/L (95% CI, 0.027‐0.247; range, 0.011‐2.90 µmol/L). BLLs of more than 0.15 µmol/L were found in 15.5% of participants. In multivariate analysis, BLLs were mainly explained by age and sex of participants (p < 0.001). A significant association was also found between BLLs and the region of residence, education level, dwelling age, occupational and leisure activities at high risk for lead exposure, smoking, and alcohol intake (p < 0.001).

CONCLUSION

BLL in blood donors is strongly explained by sex and age, a fact that can be taken into consideration when transfusing neonates.
Uric acid variation among regular blood donors is indicative of red blood cell susceptibility to storage lesion markers: A new hypothesis tested
Authors: Tzounakas Vassilis L. , Georgatzakou Hara T. , Kriebardis Anastasios G. , Papageorgiou Effie G. , Stamoulis Konstantinos E. , Foudoulaki‐Paparizos Leontini E. , Antonelou Marianna H. , Papassideri Issidora S.
Published: July 2015

BACKGROUND

Oxidative stress orchestrates a significant part of the red blood cell (RBC) storage lesion. Considering the tremendous interdonor variability observed in the “storability,” namely, the capacity of RBCs to sustain the storage lesion, this study aimed at the elucidation of donor‐specific factors that affect the redox homeostasis during the storage of RBCs in standard systems.

STUDY DESIGN AND METHODS

The hematologic profile of regular blood donors (n = 78) was evaluated by biochemical analysis of 48 different variables, including in vivo hemolysis and plasma oxidant and antioxidant factors and statistical analysis of the results. The possible effect of the uric acid (UA) variable on RBC storability was investigated in leukoreduced CPD/SAGM RBC units (n = 8) collected from donors exhibiting high or low prestorage levels of UA, throughout the storage period.

RESULTS

Among the hematologic variables examined in vivo, cluster analysis grouped the donors according to their serum UA levels. Plasma antioxidant capacity, iron indexes, and protein carbonylation represented covariants of UA factor. RBCs prepared by low‐ or high‐UA donors exhibited significant differences between them in spheroechinocytosis, supernatant antioxidant activity, and other RBC storage lesion–associated variables.

CONCLUSION

UA exhibits a storability biomarker potential. Intrinsic variability in plasma UA levels might be related to the interdonor variability observed in the storage capacity of RBCs. A model for the antioxidant effect of UA during the RBC storage is currently proposed.
Evaluation of the in‐hospital hemovigilance by introduction of the information technology–based system
Authors: Fujihara Harumi , Yamada Chiaki , Furumaki Hiroaki , Nagai Seiya , Shibata Hiroki , Ishizuka Keiko , Watanabe Hiroko , Kaneko Makoto , Adachi Miwa , Takeshita Akihiro
Published: July 2015

BACKGROUND

Hemovigilance is an important aspect of transfusion medicine. However, the frequency of the adverse reactions often varies using different reporters. Recently, we have employed a new information technology (IT)‐based in‐hospital hemovigilance system. Here, we evaluated changes in practice after implementation of an IT‐based reporting system.

STUDY DESIGN AND METHODS

We compared the rate of frequency and details of blood transfusion–related adverse reactions 3 years before and after introduction of the IT‐based reporting system. Contents and severity of the adverse reactions were reported in a paper‐based reporting system, but input by selecting items in an IT‐based reporting system. The details of adverse reactions are immediately sent to the blood transfusion unit online.

RESULTS

After we introduced the IT‐based reporting system, the reported rate of transfusion‐related adverse reactions increased approximately 10‐fold from 0.20% to 2.18% (p < 0.001), and frequencies of urticaria, pruritus, rash, fever (p < 0.001), hypertension (p = 0.001), tachycardia (p = 0.003), and nausea and vomiting (p = 0.010) increased significantly. Although there was no error report in the paper‐based reporting, incorrect reports were observed in 90 cases (0.52%) in the IT‐based reporting (p < 0.001).

CONCLUSION

The advantages of IT‐based reporting were: 1) a significant increase in the frequency of adverse reaction reporting and 2) a significant decrease in underreporting, although the true frequency has yet to be clarified. The disadvantage of the IT‐based reporting was an increased incidence of incorrect inputs, all of which was unnoticed by the reporters. Our results showed several important points in need of monitoring after introduction of an IT‐based reporting system.
Misadministration of radiation therapy in veterinary medicine: a case report and literature review
Authors: Arkans M. M. , Gieger T. L. , Nolan M. W.
Published: July 2015

Recent technical advancements in radiation therapy have allowed for improved targeting of tumours and sparing nearby normal tissues, while simultaneously decreasing the risk for medical errors by incorporating additional safety checks into electronic medical record keeping systems. The benefits of these new technologies, however, depends on their proper integration and use in the oncology clinic. Despite the advancement of technology for treatment delivery and medical record keeping, misadministration errors have a significant impact on patient care in veterinary oncology. The first part of this manuscript describes a medical incident that occurred at an academic veterinary referral hospital, in a dog receiving a combination of stereotactic radiation therapy and full‐course intensity‐modulated, image‐guided radiation therapy. The second part of the report is a literature review, which explores misadministration errors and novel challenges which arise with the implementation of advancing technologies in veterinary radiation oncology.
Identification of 5α‐reductase isoenzymes in canine skin
Authors: Bernardi de Souza Lucilene , Paradis Manon , Zamberlam Gustavo , Benoit‐Biancamano Marie‐Odile , Price Christopher
Published: July 2015

Background

Alopecia X in dogs is a noninflammatory alopecia that may be caused by a hormonal dysfunction. It may be similar to androgenic alopecia in men that is caused by the effect of dihydrotestosterone (DHT). The 5α‐reductase isoenzymes, 5αR1 and 5αR2, and a recently described 5αR3, are responsible for the conversion of testosterone into DHT. However, which 5α‐reductases are present in canine skin has not yet been described.

Objectives

The main objective of this study was to determine the pattern of expression of 5α‐reductase genes in canine skin.

Methods

Skin biopsies were obtained from healthy, intact young‐mature beagles (three males, four females) at three anatomical sites normally affected by alopecia X (dorsal neck, back of thighs and base of tail) and two sites generally unaffected (dorsal head and ventral thorax). Prostate samples (n = 3) were collected as positive controls for 5α‐reductase mRNA abundance measurement by real‐time PCR.

Results

We detected mRNA encoding 5αR1 and 5αR3 but not 5αR2. There were no significant differences in 5αR1 and 5αR3 mRNA levels between the different anatomical sites, irrespective of gender (P > 0.05). Moreover, the mean mRNA abundance in each anatomical site did not differ between males and females (P > 0.05).

Conclusions and clinical importance

To the best of the authors' knowledge, this is the first study demonstrating the expression of 5α‐reductases in canine skin and the expression of 5αR3 in this tissue. These results may help to elucidate the pathogenesis of alopecia X and to determine more appropriate treatments for this disorder.
Congenital subcutaneous arteriovenous malformation in a puppy: diagnosis with CT angiography
Authors: Proks Pavel , Stehlik Ladislav , Paninarova Michaela , Irova Katarina , Lorenzova Jana , Necas Alois
Published: July 2015

A 4‐month‐old, 20 kg, intact male, cane corso dog was presented with a slowly growing subcutaneous lesion on the left caudoventral abdominal wall. Ultrasound and computed tomography angiography revealed a subcutaneous plexus of aberrant tortuous vessels directly connected with the superficial branch of the deep circumflex iliac artery and vein. The arteriovenous malformation (AVM) was successfully surgically removed. Early recognition and surgical removal of AVM can have excellent cosmetic results and prevents potential cardiovascular complications.
Stability of coagulation protein activities in single units or pools of cryoprecipitate during storage at 20–24°C for up to 24 h
Authors: Sheffield W. P. , Bhakta V. , Jenkins C.
Published: July 2015

Background and Objective

Cryoprecipitate is a concentrated source of fibrinogen and other plasma proteins. Cryoprecipitate must be transfused within 4–6 h of thawing and storage at 20–24°C. We compared plasma protein activities in single or pooled cryoprecipitate units stored at 20–24°C for 0, 4 or 24 h.

Materials and Methods

Individual cryoprecipitate units (n = 36) were thawed, diluted with sterile saline and sampled over time. Cryoprecipitate pools of eight individual units were assembled either by serial passage of diluent (Method A, n = 6 pools) or by separate dilution into a single collection bag (Method B, n = 6 pools). Fibrinogen, factor VIII, factor XIII and von Willebrand factor activities were measured.

Results

No significant losses in activities were found relative to at‐thaw values after either 4 or 24 h of storage of individual cryoprecipitate units at 20–24°C; 35 of 36 units contained >150 mg of fibrinogen. No significant differences were found between activities in single vs. pooled units of cryoprecipitate assembled using either method, or between cryoprecipitate pools made by Method A (80–160 ml volume) or Method B (160–240 ml volume) at 0, 4 or 24 h post‐thaw; freezing and thawing of pools did not lead to significant activity losses.

Conclusion

The stability of fibrinogen and other factors in thawed cryoprecipitate stored at 20–24°C suggests that the shelf life may be safely extended to 24 h provided that sterility is maintained.
European Project “Supercritical Water Reactor–Fuel Qualification Test”: Overview, Results, Lessons Learned, and Future Outlook
Authors: Ruzickova Mariana , Vojacek Ales , Schulenberg Thomas , Visser Dirk C. , Novotny Radek , Kiss Attila , Maraczy Csaba , Toivonen Aki
Published: July 2015

The supercritical water reactor (SCWR) is one of the six reactor concepts being investigated under the framework of the Generation IV International Forum (GIF). One of the major challenges in the development of a SCWR is to develop materials for the fuel and core structures that will be sufficiently corrosion resistant to withstand supercritical water conditions and to gain thermal-hydraulic experimental data that could be used for further improvement of heat transfer predictions in the supercritical region by numerical codes. Previously, core, reactor, and plant design concepts of the European high-performance light water reactor (HPLWR) have been worked out in great detail. As the next step, it has been proposed to carry out a fuel qualification test (FQT) of a small-scale fuel assembly in a research reactor under typical prototype conditions. Design and licensing of an experimental facility for the FQT, including the small-scale fuel assembly, the required coolant loop with supercritical water, and safety and auxiliary systems, was the scope of the recently concluded project “Supercritical Water Reactor–Fuel Qualification Test” (SCWR-FQT) described here. This project was a collaborative project cofunded by the European Commission, which took advantage of a Chinese–European collaboration, in which China offered an electrically heated out-of-pile loop for testing of fuel bundles. The design of the facility, especially of the test section with the fuel assembly, and the most important results of steady-state and safety analyses are presented. Material test results of the stainless steels considered for the fuel cladding are briefly summarized. Finally, important outcomes and lessons learned in the “Education and Training” and “Management” work packages are presented.
Methodology to Design Simulated Irradiated Fuel by Maximizing Integral Indices (ck, E, G)
Authors: Sharpe Jason R. , Buijs Adriaan , Pencer Jeremy
Published: July 2015

Critical experiments are used for validation of reactor physics codes, in particular, to determine the biases and uncertainties in code predictions. To reflect all conditions present in operating reactors, plans for such experiments often require tests involving irradiated fuel. However, it is impractical to use actual irradiated fuel in critical experiments due to hazards associated with handling and transporting the fuel. To overcome this limitation, a simulated irradiated fuel, whose composition mimics the neutronic behavior of the truly irradiated fuel (TRUFUEL), can be used in a critical experiment. Here, we present an optimization method in which the composition of simulated irradiated fuel for the Canadian supercritical water-cooled reactor (SCWR) concept at midburnup (21.3  MWd kg−1 (IHM)) is varied until the integral indices ck, E, and G are maximized between the true and simulated irradiated fuel. In the optimization, the simulated irradiated fuel composition is simplified so that only the major actinides (U233, Pu238-242, and Th232) remain, while the absorbing fission products are replaced by dysprosia and zirconia. In this method, the integral indices ck, E, and G are maximized while the buckling, k∞ and the relative ring-averaged pin fission powers are constrained, within a certain tolerance, to their reference lattice values. Using this method, maximized integral similarity indices of ck=0.967, E=0.992, and G=0.891 have been obtained.
Physical Activity Energy Expenditure and Sarcopenia in Black South African Urban Women
Authors: Kruger Herculina S. , Havemann-Nel Lize , Ravyse Chrisna , Moss Sarah J. , Tieland Michael
Published: July 2015

Background:

Black women are believed to be genetically less predisposed to age-related sarcopenia. The objective of this study was to investigate lifestyle factors associated with sarcopenia in black South African (SA) urban women.

Methods:

In a cross-sectional study, 247 women (mean age 57 y) were randomly selected. Anthropometric and sociodemographic variables, dietary intakes, and physical activity were measured. Activity was also measured by combined accelerometery/heart rate monitoring (ActiHeart), and HIV status was tested. Dual energy x-ray absorptiometry was used to measure appendicular skeletal mass (ASM). Sarcopenia was defined according to a recently derived SA cutpoint of ASM index (ASM/height squared) < 4.94 kg/m2.

Results:

In total, 8.9% of the women were sarcopenic, decreasing to 8.1% after exclusion of participants who were HIV positive. In multiple regressions with ASM index, grip strength, and gait speed, respectively, as dependent variables, only activity energy expenditure (β = .27) was significantly associated with ASM index. Age (β = –.50) and activity energy expenditure (β = .17) were significantly associated with gait speed. Age (β = –.11) and lean mass (β = .21) were significantly associated with handgrip strength.

Conclusions:

Sarcopenia was prevalent among these SA women and was associated with low physical activity energy expenditure.
The interaction of heparan sulfate proteoglycans with endothelial transglutaminase-2 limits VEGF
165
-induced angiogenesis
Authors: Beckouche Nathan , Bignon Marine , Lelarge Virginie , Mathivet Thomas , Pichol-Thievend Cathy , Berndt Sarah , Hardouin Julie , Garand Marion , Ardidie-Robouant Corinne , Barret Alain , Melino Gerry , Lortat-Jacob Hugues , Muller Laurent , Monnot Catherine , Germain Stephane
Published: July 2015

Transglutaminase-2 attenuates blood vessel formation by preventing heparan sulfate from potentiating signaling by a VEGF isoform.
Limiting innate overreaction
Authors: Ferrarelli Leslie K.
Published: July 2015

Some people are less susceptible to a hyperactive inflammatory response due to a polymorphism in the E3 ubiquitin ligase HECTD2.
Structure of a sterol sensor
Authors: Vinson Valda
Published: July 2015

The structure of a bacterial homolog of insulin-induced trans-membrane sterol receptors elucidates their structure and function.
Single-cell measurements map immunity
Authors: Ray L. Bryan
Published: July 2015

Cytometry meets mass spectrometry to create a functional map of the immune system.
Non-O1/Non-O139 Vibrio cholerae Avian Isolate from France Cocarrying the
bla
VIM-1
and
bla
VIM-4
Genes
Authors: Aberkane Salim , Compain Fabrice , Barraud Olivier , Ouédraogo Abdoul-Salam , Bouzinbi Nicolas , Vittecoq Marion , Jean-Pierre Hélène , Decré Dominique , Godreuil Sylvain
Published: July 2015

We describe here a non-O1/non-O139
Vibrio cholerae
isolate producing both VIM-1 and VIM-4 carbapenemases. It was isolated from a yellow-legged gull in southern France. The
bla
VIM
genes were part of a class 1 integron structure located in an IncA/C plasmid. This study emphasizes the presence of carbapenemase genes in wildlife microbiota.
Concomitant Benznidazole and Suramin Chemotherapy in Mice Infected with a Virulent Strain of Trypanosoma cruzi
Authors: Santos Eliziária C. , Novaes Rômulo D. , Cupertino Marli C. , Bastos Daniel S. S. , Klein Raphael C. , Silva Eduardo A. M. , Fietto Juliana L. R. , Talvani André , Bahia Maria T. , Oliveira Leandro L.
Published: July 2015

Although suramin (Sur) is suggested as a potential drug candidate in the management of Chagas disease, this issue has not been objectively tested. In this study, we examined the applicability of concomitant treatment with benznidazole (Bz) and suramin in mice infected with a virulent strain of
Trypanosoma cruzi
. Eighty 12-week-old male C57BL/6 mice were equally randomized in eight groups: (i) noninfected mice (negative control) and mice infected with
T. cruzi
Y strain receiving (ii) no treatment (positive control), (iii) Bz, 100 mg/kg of body weight per day, (iv) Sur, 20 mg/kg/day, and (v to viii) Sur, 20 mg/kg/day, combined with Bz, 100, 50, 25, or 5 mg/kg/day. Bz was administered by gavage, and Sur was administered intraperitoneally. Sur dramatically increased the parasitemia, cardiac content of parasite DNA, inflammation, oxidative tissue damage, and mortality. In response to high parasitic load in cardiac tissue, Sur stimulated the immune system in a manner typical of the acute phase of Chagas disease, increasing tissue levels of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) and inducing a preferential IgG2a anti-
T. cruzi
serum pattern. When Sur and Bz were combined, the infection severity was attenuated, showing a dose-dependent Bz response. Sur therapy had a more harmful effect on the host than on the parasite and reduced the efficacy of Bz against
T. cruzi
infection. Considering that Sur drastically reinforced the infection evolution, potentiating the inflammatory process and the severity of cardiac lesions, the
in vivo
findings contradicted the
in vitro
anti-
T. cruzi
potential described for this drug.
Cellular Pharmacokinetics and Intracellular Activity of the Novel Peptide Deformylase Inhibitor GSK1322322 against Staphylococcus aureus Laboratory and Clinical Strains with Various Resistance Phenotypes: Studies with Human THP-1 Monocytes and J774 Murine Macrophages
Authors: Peyrusson Frédéric , Butler Deborah , Tulkens Paul M. , Van Bambeke Françoise
Published: July 2015

GSK1322322 is a peptide deformylase inhibitor active againstStaphylococcus aureusstrains resistant to currently marketed antibiotics. Our aim was to assess the activity of GSK1322322 against intracellularS. aureususing anin vitropharmacodynamic model and, in parallel, to examine its cellular pharmacokinetics and intracellular disposition. For intracellular activity analysis, we used an established model of human THP-1 monocytes and tested one fully susceptibleS. aureusstrain (ATCC 25923) and 8 clinical strains with resistance to oxacillin, vancomycin, daptomycin, macrolides, clindamycin, linezolid, or moxifloxacin. Uptake, accumulation, release, and subcellular distribution (cell fractionation) of [14C]GSK1322322 were examined in uninfected murine J774 macrophages and uninfected and infected THP-1 monocytes. GSK1322322 demonstrated a uniform activity against the intracellular forms of allS. aureusstrains tested, disregarding their resistance phenotypes, with a maximal relative efficacy (Emax) of a 0.5 to 1 log10CFU decrease compared to the original inoculum within 24 h and a static concentration (Cs) close to its MIC in broth. Influx and efflux were very fast (<5 min to equilibrium), and accumulation was about 4-fold, with no or a minimal effect of the broad-spectrum eukaryotic efflux transporter inhibitors gemfibrozil and verapamil. GSK1322322 was recovered in the cell-soluble fraction and was dissociated from the main subcellular organelles and from bacteria (in infected cells). The results of this study show that GSK1322322, as a typical novel deformylase inhibitor, may act against intracellular forms ofS. aureus. They also suggest that GSK1322322 has the ability to freely diffuse into and out of eukaryotic cells as well as within subcellular compartments.
IncA/C Plasmid Carrying
bla
NDM-1
,
bla
CMY-16
, and
fosA3
in a Salmonella enterica Serovar Corvallis Strain Isolated from a Migratory Wild Bird in Germany
Authors: Villa L. , Guerra B. , Schmoger S. , Fischer J. , Helmuth R. , Zong Z. , García-Fernández A. , Carattoli A.
Published: July 2015

A
Salmonella enterica
serovar Corvallis strain was isolated from a wild bird in Germany. This strain carried the IncA/C
2
pRH-1238 plasmid. Complete sequencing of the plasmid was performed, identifying the
bla
NDM-1
,
bla
CMY-16
,
fosA3
,
sul1
,
sul2
,
strA
,
strB
,
aac(6
′
)-Ib
,
aadA5
,
aphA6
,
tetA
(A),
mphA
,
floR
,
dfrA7
, and
merA
genes, which confer clinically relevant resistance to most of the antimicrobial classes, including β-lactams with carbapenems, fosfomycin, aminoglycosides, co-trimoxazole, tetracyclines, and macrolides. The strain likely originated from the Asiatic region and was transferred to Germany through the
Milvus migrans
migratory route.
Multidrug Transporters and Alterations in Sterol Biosynthesis Contribute to Azole Antifungal Resistance in Candida parapsilosis
Authors: Berkow Elizabeth L. , Manigaba Kayihura , Parker Josie E. , Barker Katherine S. , Kelly Stephen L. , Rogers P. David
Published: July 2015

While much is known concerning azole resistance in
Candida albicans
, considerably less is understood about
Candida parapsilosis
, an emerging species of
Candida
with clinical relevance. We conducted a comprehensive analysis of azole resistance in a collection of resistant
C. parapsilosis
clinical isolates in order to determine which genes might play a role in this process within this species. We examined the relative expression of the putative drug transporter genes
CDR1
and
MDR1
and that of
ERG11
. In isolates overexpressing these genes, we sequenced the genes encoding their presumed transcriptional regulators,
TAC1
,
MRR1
, and
UPC2
, respectively. We also sequenced the sterol biosynthesis genes
ERG3
and
ERG11
in these isolates to find mutations that might contribute to this phenotype in this
Candida
species. Our findings demonstrate that the putative drug transporters Cdr1 and Mdr1 contribute directly to azole resistance and suggest that their overexpression is due to activating mutations in the genes encoding their transcriptional regulators. We also observed that the Y132F substitution in
ERG11
is the only substitution occurring exclusively among azole-resistant isolates, and we correlated this with specific changes in sterol biosynthesis. Finally, sterol analysis of these isolates suggests that other changes in sterol biosynthesis may contribute to azole resistance in
C. parapsilosis
.
Fast and Accurate Large-Scale Detection of β-Lactamase Genes Conferring Antibiotic Resistance
Authors: Lee Jae Jin , Lee Jung Hun , Kwon Dae Beom , Jeon Jeong Ho , Park Kwang Seung , Lee Chang-Ro , Lee Sang Hee
Published: July 2015

Fast detection of β-lactamase (
bla
) genes allows improved surveillance studies and infection control measures, which can minimize the spread of antibiotic resistance. Although several molecular diagnostic methods have been developed to detect limited
bla
gene types, these methods have significant limitations, such as their failure to detect almost all clinically available
bla
genes. We developed a fast and accurate molecular method to overcome these limitations using 62 primer pairs, which were designed through elaborate optimization processes. To verify the ability of this large-scale
bla
detection method (
large-scale
bla
Finder), assays were performed on previously reported bacterial control isolates/strains. To confirm the applicability of the
large-scale
bla
Finder, the assays were performed on unreported clinical isolates. With perfect specificity and sensitivity in 189 control isolates/strains and 403 clinical isolates, the
large-scale
bla
Finder detected almost all clinically available
bla
genes. Notably, the
large-scale
bla
Finder detected 24 additional unreported
bla
genes in the isolates/strains that were previously studied, suggesting that previous methods detecting only limited types of
bla
genes can miss unexpected
bla
genes existing in pathogenic bacteria, and our method has the ability to detect almost all
bla
genes existing in a clinical isolate. The ability of
large-scale
bla
Finder to detect
bla
genes on a large scale enables prompt application to the detection of almost all
bla
genes present in bacterial pathogens. The widespread use of the
large-scale
bla
Finder in the future will provide an important aid for monitoring the emergence and dissemination of
bla
genes and minimizing the spread of resistant bacteria.
Coexistence of Heavy Metal and Antibiotic Resistance within a Novel Composite Staphylococcal Cassette Chromosome in a Staphylococcus haemolyticus Isolate from Bovine Mastitis Milk
Authors: Xue Huping , Wu Zhaowei , Li Longping , Li Fan , Wang Yiqing , Zhao Xin
Published: July 2015

The structure of a composite staphylococcal cassette chromosome (SCC) carried by a methicillin-resistant
Staphylococcus haemolyticus
(NW19A) isolated from a bovine milk sample was analyzed. The formation of the circular forms of both single SCC elements and composite SCC elements was detected in NW19A. Twenty heavy metal and antibiotic resistance-related genes coexisted in this composite SCC, suggesting that these genes might be coselected under environmental pressure. The
mec
gene complex in NW19A, designated type C3, is different from classic C1 or C2 gene complexes structurally and likely evolves differently. Furthermore, results from alignment of the SCC composite island of NW19A with 50 related sequences from different staphylococcal strains provided additional evidence to support the notion that coagulase-negative staphylococci (CoNS) are the original host of heavy metal resistance genes among staphylococci. Given that a SCC composite island could transfer freely among different staphylococcal species from different hosts, more attention should be paid to contamination with heavy metals and antibiotics in dairy farming environments, including wastewater, soil, feces, and feed.
Immunization with the MAEBL M2 Domain Protects against Lethal Plasmodium yoelii Infection
Authors: Leite Juliana A. , Bargieri Daniel Y. , Carvalho Bruna O. , Albrecht Letusa , Lopes Stefanie C. P. , Kayano Ana Carolina A. V. , Farias Alessandro S. , Chia Wan Ni , Claser Carla , Malleret Benoit , Russell Bruce , Castiñeiras Catarina , Santos Leonilda M. B. , Brocchi Marcelo , Wunderlich Gerhard , Soares Irene S. , Rodrigues Mauricio M. , Rénia Laurent , Costa Fabio T. M.
Published: July 2015

Malaria remains a world-threatening disease largely because of the lack of a long-lasting and fully effective vaccine. MAEBL is a type 1 transmembrane molecule with a chimeric cysteine-rich ectodomain homologous to regions of the Duffy binding-like erythrocyte binding protein and apical membrane antigen 1 (AMA1) antigens. Although MAEBL does not appear to be essential for the survival of blood-stage forms, ectodomains M1 and M2, homologous to AMA1, seem to be involved in parasite attachment to erythrocytes, especially M2. MAEBL is necessary for sporozoite infection of mosquito salivary glands and is expressed in liver stages. Here, thePlasmodium yoeliiMAEBL-M2 domain was expressed in a prokaryotic vector. C57BL/6J mice were immunized with doses ofP. yoeliirecombinant protein rPyM2-MAEBL. High levels of antibodies, with balanced IgG1 and IgG2c subclasses, were achieved. rPyM2-MAEBL antisera were capable of recognizing the native antigen. Anti-MAEBL antibodies recognized different MAEBL fragments expressed in CHO cells, showing stronger IgM and IgG responses to the M2 domain and repeat region, respectively. After a challenge withP. yoeliiYM (lethal strain)-infected erythrocytes (IE), up to 90% of the immunized animals survived and a reduction of parasitemia was observed. Moreover, splenocytes harvested from immunized animals proliferated in a dose-dependent manner in the presence of rPyM2-MAEBL. Protection was highly dependent on CD4+, but not CD8+, T cells toward Th1. rPyM2-MAEBL antisera were also able to significantly inhibit parasite development, as observed inex vivoP. yoeliierythrocyte invasion assays. Collectively, these findings support the use of MAEBL as a vaccine candidate and open perspectives to understand the mechanisms involved in protection.
Phosphoantigen Burst upon Plasmodium falciparum Schizont Rupture Can Distantly Activate Vγ9Vδ2 T Cells
Authors: Guenot Marianne , Loizon Séverine , Howard Jennifer , Costa Giulia , Baker David A. , Mohabeer Shaneel Y. , Troye-Blomberg Marita , Moreau Jean-François , Déchanet-Merville Julie , Mercereau-Puijalon Odile , Mamani-Matsuda Maria , Behr Charlotte
Published: July 2015

Malaria induces potent activation and expansion of the Vγ9Vδ2 subpopulation of γδT cells, which inhibit thePlasmodium falciparumblood cycle through soluble cytotoxic mediators, abrogating merozoite invasion capacity. Intraerythrocytic stages efficiently trigger Vγ9Vδ2 T-cell activation and degranulation through poorly understood mechanisms.P. falciparumblood-stage extracts are known to contain phosphoantigens able to stimulate Vγ9Vδ2 T cells, but how these are presented by intact infected red blood cells (iRBCs) remains elusive. Here we show that, unlike activation by phosphoantigen-expressing cells, Vγ9Vδ2 T-cell activation by intact iRBCs is independent of butyrophilin expression by the iRBC, and contact with an intact iRBC is not required. Moreover, blood-stage culture supernatants proved to be as potent activators of Vγ9Vδ2 T cells as iRBCs. Bioactivity in the microenvironment is attributable to phosphoantigens, as it is dependent on the parasite DOXP pathway, on Vγ9Vδ2 TCR signaling, and on butyrophilin expression by Vγ9Vδ2 T cells. Kinetic studies showed that the phosphoantigens were released at the end of the intraerythrocytic cycle at the time of parasite egress. We document exquisite sensitivity of Vγ9Vδ2 T cells, which respond to a few thousand parasites. These data unravel a novel framework, whereby release of phosphoantigens into the extracellular milieu by sequestered parasites likely promotes activation of distant Vγ9Vδ2 T cells that in turn exert remote antiparasitic functions.
Fecal Microbiota Transplantation Eliminates Clostridium difficile in a Murine Model of Relapsing Disease
Authors: Seekatz Anna M. , Theriot Casey M. , Molloy Caitlyn T. , Wozniak Katherine L. , Bergin Ingrid L. , Young Vincent B.
Published: July 2015

Recurrent
Clostridium difficile
infection (CDI) is of particular concern among health care-associated infections. The role of the microbiota in disease recovery is apparent given the success of fecal microbiota transplantation (FMT) for recurrent CDI. Here, we present a murine model of CDI relapse to further define the microbiota recovery following FMT. Cefoperazone-treated mice were infected with
C. difficile
630 spores and treated with vancomycin after development of clinical disease. Vancomycin treatment suppressed both
C. difficile
colonization and cytotoxin titers. However,
C. difficile
counts increased within 7 days of completing treatment, accompanied by relapse of clinical signs. The administration of FMT immediately after vancomycin cleared
C. difficile
and decreased cytotoxicity within 1 week. The effects of FMT on the gut microbiota community were detectable in recipients 1-day posttransplant. Conversely, mice not treated with FMT remained persistently colonized with high levels of
C. difficile
, and the gut microbiota in these mice persisted at low diversity. These results suggest that full recovery of colonization resistance against
C. difficile
requires the restoration of a specific community structure.
Induction of Multifunctional Broadly Reactive T Cell Responses by a Plasmodium vivax Circumsporozoite Protein Recombinant Chimera
Authors: Cabrera-Mora Monica , Fonseca Jairo Andres , Singh Balwan , Oliveira-Ferreira Joseli , Lima-Junior Josué da Costa , Calvo-Calle J. Mauricio , Moreno Alberto
Published: July 2015

Plasmodium vivaxis the most widespread species ofPlasmodium, causing up to 50% of the malaria cases occurring outside sub-Saharan Africa. An effective vaccine is essential for successful control and potential eradication. A well-characterized vaccine candidate is the circumsporozoite protein (CSP). Preclinical and clinical trials have shown that both antibodies and cellular immune responses have been correlated with protection induced by immunization with CSP. On the basis of our reported approach of developing chimericPlasmodium yoeliiproteins to enhance protective efficacy, we designed PvRMC-CSP, a recombinant chimeric protein based on theP. vivaxCSP (PvCSP). In this engineered protein, regions of the PvCSP predicted to contain human T cell epitopes were genetically fused to an immunodominant B cell epitope derived from the N-terminal region I and to repeat sequences representing the two types of PvCSP repeats. The chimeric protein was expressed in soluble form with high yield. As the immune response to PvCSP has been reported to be genetically restricted in the murine model, we tested the immunogenicity of PvRMC-CSP in groups of six inbred strains of mice. PvRMC-CSP was able to induce robust antibody responses in all the mouse strains tested. Synthetic peptides representing the allelic forms of theP. vivaxCSP were also recognized to a similar extent regardless of the mouse strain. Furthermore, the immunization regimen induced high frequencies of multifunctional CD4+and CD8+PvRMC-CSP-specific T cells. The depth and breadth of the immune responses elicited suggest that immunization with PvRMC-CSP can circumvent the genetic restriction of the immune response toP. vivaxCSP. Interestingly, PvRMC-CSP was also recognized by naturally acquired antibodies from individuals living in areas where malaria is endemic. These features make PvRMC-CSP a promising vaccine candidate for further development.
Type II Secretion-Dependent Degradative and Cytotoxic Activities Mediated by Stenotrophomonas maltophilia Serine Proteases StmPr1 and StmPr2
Authors: DuMont Ashley L. , Karaba Sara M. , Cianciotto Nicholas P.
Published: July 2015

Stenotrophomonas maltophilia
is an emerging opportunistic pathogen that primarily causes pneumonia and bacteremia in immunocompromised individuals. We recently reported that
S. maltophilia
strain K279a encodes the Xps type II secretion system and that Xps promotes rounding, actin rearrangement, detachment, and death in the human lung epithelial cell line A549. Here, we show that Xps-dependent cell rounding and detachment occur with multiple human and murine cell lines and that serine protease inhibitors block Xps-mediated rounding and detachment of A549 cells. Using genetic analysis, we determined that the serine proteases StmPr1 and StmPr2, which were confirmed to be Xps substrates, are predominantly responsible for secreted proteolytic activities exhibited by strain K279a, as well as the morphological and cytotoxic effects on A549 cells. Supernatants from strain K279a also promoted the degradation of type I collagen, fibrinogen, and fibronectin in a predominantly Xps- and protease-dependent manner, although some Xps-independent degradation of fibrinogen was observed. Finally, Xps, and predominantly StmPr1, degraded interleukin 8 (IL-8) secreted by A549 cells during coculture with strain K279a. Our findings indicate that while StmPr1 and StmPr2 are predominantly responsible for A549 cell rounding, extracellular matrix protein degradation, and IL-8 degradation, additional Xps substrates also contribute to these activities. Altogether, our data provide new insight into the virulence potential of the
S. maltophilia
Xps type II secretion system and its StmPr1 and StmPr2 substrates.
GlnR-Mediated Regulation of
ectABCD
Transcription Expands the Role of the GlnR Regulon to Osmotic Stress Management
Authors: Shao ZhiHui , Deng WanXin , Li ShiYuan , He JuanMei , Ren ShuangXi , Huang WeiRen , Lu YinHua , Zhao GuoPing , Cai ZhiMing , Wang Jin
Published: July 2015

Ectoine and hydroxyectoine are excellent compatible solutes for bacteria to deal with environmental osmotic stress and temperature damages. The biosynthesis cluster of ectoine and hydroxyectoine is widespread among microorganisms, and its expression is activated by high salinity and temperature changes. So far, little is known about the mechanism of the regulation of the transcription of
ect
genes and only two MarR family regulators (EctR1 in methylobacteria and the EctR1-related regulator CosR in
Vibrio cholerae
) have been found to negatively regulate the expression of
ect
genes. Here, we characterize GlnR, the global regulator for nitrogen metabolism in actinomycetes, as a negative regulator for the transcription of ectoine/hydroxyectoine biosynthetic genes (
ect
operon) in
Streptomyces coelicolor
. The physiological role of this transcriptional repression by GlnR is proposed to protect the intracellular glutamate pool, which acts as a key nitrogen donor for both the nitrogen metabolism and the ectoine/hydroxyectoine biosynthesis.

IMPORTANCE
High salinity is deleterious, and cells must evolve sophisticated mechanisms to cope with this osmotic stress. Although production of ectoine and hydroxyectoine is one of the most frequently adopted strategies, the in-depth mechanism of regulation of their biosynthesis is less understood. So far, only two MarR family negative regulators, EctR1 and CosR, have been identified in methylobacteria and
Vibrio
, respectively. Here, our work demonstrates that GlnR, the global regulator for nitrogen metabolism, is a negative transcriptional regulator for
ect
genes in
Streptomyces coelicolor
. Moreover, a close relationship is found between nitrogen metabolism and osmotic resistance, and GlnR-mediated regulation of
ect
transcription is proposed to protect the intracellular glutamate pool. Meanwhile, the work reveals the multiple roles of GlnR in bacterial physiology.
Orientia tsutsugamushi Strain Ikeda Ankyrin Repeat-Containing Proteins Recruit SCF1 Ubiquitin Ligase Machinery via Poxvirus-Like F-Box Motifs
Authors: Beyer Andrea R. , VieBrock Lauren , Rodino Kyle G. , Miller Daniel P. , Tegels Brittney K. , Marconi Richard T. , Carlyon Jason A.
Published: July 2015

A rising theme among intracellular microbes is the delivery of ankyrin repeat-containing effectors (Anks) that interact with target proteins to co-opt host cell functions.
Orientia tsutsugamushi
, an obligate intracellular bacterium and the etiologic agent of scrub typhus, encodes one of the largest Ank repertoires of any sequenced microorganism. They have been previously identified as type 1 secretion system substrates. Here,
in silico
and manual sequence analyses revealed that a large proportion of
O. tsutsugamushi
strain Ikeda Anks bear a eukaryotic/poxvirus-like F-box motif, which is known to recruit host cell SCF1 ubiquitin ligase machinery. We assessed the Anks for the ability to serve as F-box proteins. Coimmunoprecipitation assays demonstrated that F-box-containing Anks interact with overexpressed and/or endogenous SCF1 components. When coexpressed with FLAG-Ank4_01 or FLAG-Ank9, a glutathione
S
-transferase (GST)-tagged version of the SCF1 component SKP1 localized to subcellular sites of FLAG-Ank accumulation. The abilities of recombinant Anks to interact and colocalize with SKP1 were F-box dependent. GST-SKP1 precipitated
O. tsutsugamushi
-derived Ank9 from infected host cells, verifying both that the pathogen expresses Ank9 during infection and the protein's capability to bind SKP1. Aligning
O. tsutsugamushi
, poxviral, and eukaryotic F-box sequences delineated three F-box residues that are highly conserved and likely to be functionally important. Substitution of these residues ablated the ability of GFP-Ank9 to interact with GST-SKP1. These results demonstrate that
O. tsutsugamushi
strain Ikeda Anks can co-opt host cell polyubiquitination machinery, provide the first evidence that an
O. tsutsugamushi
Ank does so during infection, and advance overall understanding of microbial F-box proteins.

IMPORTANCE
Ankyrin repeat-containing proteins (Anks) are important virulence factors of intracellular bacteria that mediate protein-protein interactions with host cell targets.
Orientia tsutsugamushi
, which causes a debilitating infection called scrub typhus in one of the most densely populated regions of the world, encodes one of the largest Ank armamentariums of any sequenced bacterium. This study demonstrates that
O. tsutsugamushi
strain Ikeda Anks also bear F-box motifs that interact with host cell polyubiquitination machinery. By proving that an
Orientia
-derived Ank interacts with SKP1 in infected cells, this evidences the first bona fide
Orientia
effector and the first example of an endogenous F-box-containing Ank–mammalian-host ligand interaction for any intracellular bacterium. Also, importantly, this work identifies key residues that are essential for microbial F-box function.