bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergence of Extensively Drug-Resistant Proteus mirabilis Harboring a Conjugative NDM-1 Plasmid and a Novel Salmonella Genomic Island 1 Variant, SGI1-Z
Authors: Qin Shangshang , Qi Hui , Zhang Qijing , Zhao Di , Liu Zhen-Zhen , Tian Hao , Xu Lijuan , Xu Hui , Zhou Mengmeng , Feng Xianju , Liu Hong-Min
Published: July 2015

Acquisition of
bla
NDM-1
in bacterial species, such as
Proteus mirabilis
that is intrinsically resistant to tetracycline, tigecycline and colistin, will make clinical treatment extremely difficult. Here, we characterized an NDM-1-producing clinical isolate of
P. mirabilis
(PM58) that displayed an extensively drug-resistant (XDR) phenotype, susceptible only to aztreonam. Molecular analysis revealed that PM58 harbored both a conjugative NDM-1 plasmid and a novel
Salmonella
genomic island 1 variant on chromosome.
Potential Targets for Antifungal Drug Discovery Based on Growth and Virulence in Candida albicans
Authors: Li Xiuyun , Hou Yinglong , Yue Longtao , Liu Shuyuan , Du Juan , Sun Shujuan
Published: July 2015

Fungal infections, especially infections caused by
Candida albicans
, remain a challenging problem in clinical settings. Despite the development of more-effective antifungal drugs, their application is limited for various reasons. Thus, alternative treatments with drugs aimed at novel targets in
C. albicans
are needed. Knowledge of growth and virulence in fungal cells is essential not only to understand their pathogenic mechanisms but also to identify potential antifungal targets. This article reviews the current knowledge of the mechanisms of growth and virulence in
C. albicans
and examines potential targets for the development of new antifungal drugs.
Carriage of Escherichia coli Producing CTX-M-Type Extended-Spectrum β-Lactamase in Healthy Vietnamese Individuals
Authors: Bui Thi Mai Huong , Hirai Itaru , Ueda Shuhei , Bui Thi Kim Ngan , Hamamoto Kouta , Toyosato Takehiko , Le Danh Tuyen , Yamamoto Yoshimasa
Published: July 2015

Healthy carriage of CTX-M-type extended-spectrum β-lactamase (ESBL)-producing
Escherichia coli
was examined by thrice collecting fecal samples from the same 199 healthy Vietnamese subjects every 6 months. Using pulsed-field gel electrophoresis (PFGE), identical PFGE patterns throughout the three samplings were not observed, although prevalence of
E. coli
in the subjects was around 50% in the three samplings. Our results suggested a short carriage period of the CTX-M-type ESBL-producing
E. coli
in healthy Vietnamese subjects.
Antimicrobial Activity of Fosfomycin-Tobramycin Combination against Pseudomonas aeruginosa Isolates Assessed by Time-Kill Assays and Mutant Prevention Concentrations
Authors: Díez-Aguilar María , Morosini María Isabel , Tedim Ana P. , Rodríguez Irene , Aktaş Zerrin , Cantón Rafael
Published: July 2015

The antibacterial activity of fosfomycin-tobramycin combination was studied by time-kill assay in eight
Pseudomonas aeruginosa
clinical isolates belonging to the fosfomycin wild-type population (MIC = 64 μg/ml) but with different tobramycin susceptibilities (MIC range, 1 to 64 μg/ml). The mutant prevention concentration (MPC) and mutant selection window (MSW) were determined in five of these strains (tobramycin MIC range, 1 to 64 μg/ml) in aerobic and anaerobic conditions simulating environments that are present in biofilm-mediated infections. Fosfomycin-tobramycin was synergistic and bactericidal for the isolates with mutations in the
mexZ
repressor gene, with a tobramycin MIC of 4 μg/ml. This effect was not observed in strains displaying tobramycin MICs of 1 to 2 μg/ml due to the strong bactericidal effect of tobramycin alone. Fosfomycin presented higher MPC values (range, 2,048 to >2,048 μg/ml) in aerobic and anaerobic conditions than did tobramycin (range, 16 to 256 μg/ml). Interestingly, the association rendered narrow or even null MSWs in the two conditions. However, for isolates with high-level tobramycin resistance that harbored aminoglycoside nucleotidyltransferases, time-kill assays showed no synergy, with wide MSWs in the two environments.
glpT
gene mutations responsible for fosfomycin resistance in
P. aeruginosa
were determined in fosfomycin-susceptible wild-type strains and mutant derivatives recovered from MPC studies. All mutant derivatives had changes in the GlpT amino acid sequence, which resulted in a truncated permease responsible for fosfomycin resistance. These results suggest that fosfomycin-tobramycin can be an alternative for infections due to
P. aeruginosa
since it has demonstrated synergistic and bactericidal activity in susceptible isolates and those with low-level tobramycin resistance. It also prevents the emergence of resistant mutants in either aerobic or anaerobic environments.
Potent
Ex Vivo
Activity of Naphthoquine and Methylene Blue against Drug-Resistant Clinical Isolates of Plasmodium falciparum and Plasmodium vivax
Authors: Wirjanata Grennady , Sebayang Boni F. , Chalfein Ferryanto , Prayoga  , Handayuni Irene , Trianty Leily , Kenangalem Enny , Noviyanti Rintis , Campo Brice , Poespoprodjo Jeanne Rini , Möhrle Jörg J. , Price Ric N. , Marfurt Jutta
Published: July 2015

The 4-aminoquinoline naphthoquine (NQ) and the thiazine dye methylene blue (MB) have potent
in vitro
efficacies against
Plasmodium falciparum
, but susceptibility data for
P. vivax
are limited. The species- and stage-specific
ex vivo
activities of NQ and MB were assessed using a modified schizont maturation assay on clinical field isolates from Papua, Indonesia, where multidrug-resistant
P. falciparum
and
P. vivax
are prevalent. Both compounds were highly active against
P. falciparum
(median [range] 50% inhibitory concentration [IC
50
]: NQ, 8.0 nM [2.6 to 71.8 nM]; and MB, 1.6 nM [0.2 to 7.0 nM]) and
P. vivax
(NQ, 7.8 nM [1.5 to 34.2 nM]; and MB, 1.2 nM [0.4 to 4.3 nM]). Stage-specific drug susceptibility assays revealed significantly greater IC
50
s in parasites exposed at the trophozoite stage than at the ring stage for NQ in
P. falciparum
(26.5 versus 5.1 nM,
P
= 0.021) and
P. vivax
(341.6 versus 6.5 nM,
P
= 0.021) and for MB in
P. vivax
(10.1 versus 1.6 nM,
P
= 0.010). The excellent
ex vivo
activities of NQ and MB against both
P. falciparum
and
P. vivax
highlight their potential utility for the treatment of multidrug-resistant malaria in areas where both species are endemic.
Effective Antibiofilm Polyketides against Staphylococcus aureus from the Pyranonaphthoquinone Biosynthetic Pathways of Streptomyces Species
Authors: Oja Terhi , San Martin Galindo Paola , Taguchi Takaaki , Manner Suvi , Vuorela Pia M. , Ichinose Koji , Metsä-Ketelä Mikko , Fallarero Adyary
Published: July 2015

Streptomyces
bacteria are renowned for their ability to produce bioactive secondary metabolites. Recently, synthetic biology has enabled the production of intermediates and shunt products, which may have altered biological activities compared to the end products of the pathways. Here, we have evaluated the potential of recently isolated alnumycins and other closely related pyranonaphthoquinone (PNQ) polyketides against
Staphylococcus aureus
biofilms. The antimicrobial potency of the compounds against planktonic cells and biofilms was determined by redox dye-based viability staining, and the antibiofilm efficacy of the compounds was confirmed by viable counting. A novel antistaphylococcal polyketide, alnumycin D, was identified. Unexpectedly, the
C
-ribosylated pathway shunt product alnumycin D was more active against planktonic and biofilm cells than the pathway end product alnumycin A, where a ribose unit has been converted into a dioxane moiety. The evaluation of the antibiofilm potential of other alnumycins revealed that the presence of the ribose moiety in pyranose form is essential for high activity against preformed biofilms. Furthermore, the antibiofilm potential of other closely related PNQ polyketides was examined. Based on their previously reported activity against planktonic
S. aureus
cells, granaticin B, kalafungin, and medermycin were also selected for testing, and among them, granaticin B was found to be the most potent against preformed biofilms. The most active antibiofilm PNQs, alnumycin D and granaticin B, share several structural features that may be important for their antibiofilm activity. They are uncharged, glycosylated, and also contain a similar oxygenation pattern of the lateral naphthoquinone ring. These findings highlight the potential of antibiotic biosynthetic pathways as a source of effective antibiofilm compounds.
Subinhibitory Doses of Aminoglycoside Antibiotics Induce Changes in the Phenotype of Mycobacterium abscessus
Authors: Tsai Sheng-Hui , Lai Hsin-Chih , Hu Shiau-Ting
Published: July 2015

Subinhibitory doses of antibiotics have been shown to cause changes in bacterial morphology, adherence ability, and resistance to antibiotics. In this study, the effects of subinhibitory doses of aminoglycoside antibiotics on
Mycobacterium abscessus
were investigated. The treatment of
M. abscessus
cells with subinhibitory doses of amikacin was found to change their colony from a smooth to a rough morphotype and increase their ability to adhere to a polyvinylchloride plate, aggregate in culture, and resist phagocytosis and killing by macrophages.
M. abscessus
cells treated with a subinhibitory dose of amikacin also became more potent in Toll-like receptor 2 (TLR-2) stimulation, leading to increased tumor necrosis factor alpha (TNF-α) production by macrophages. The MAB_3508c gene was shown to play a role in mediating these phenotypic changes, as its expression in
M. abscessus
cells was increased when they were treated with a subinhibitory dose of amikacin. In addition, overexpression of MAB_3508c in
M. abscessus
cells caused changes similar to those induced by subinhibitory doses of amikacin, including a switch from smooth to rough colony morphology, increased ability to aggregate in liquid culture, decreased motility, and increased resistance to killing by macrophages. These findings suggest the importance of using sufficient doses of antibiotics for the treatment of
M. abscessus
infections.
First Report of Ceftazidime-Avibactam Resistance in a KPC-3-Expressing Klebsiella pneumoniae Isolate
Authors: Humphries Romney M. , Yang Shangxin , Hemarajata Peera , Ward Kevin W. , Hindler Janet A. , Miller Shelley A. , Gregson Aric
Published: July 2015

Ceftazidime-avibactam is the first antimicrobial approved by the U.S. FDA for the treatment of carbapenem-resistant
Enterobacteriaceae
. Avibactam, a non-β-lactam β-lactamase inhibitor, inactivates class A serine carbapenemases, including
Klebsiella pneumoniae
carbapenemase (KPC). We report a KPC-producing
K. pneumoniae
isolate resistant to ceftazidime-avibactam (MIC, 32/4 μg/ml) from a patient with no prior treatment with ceftazidime-avibactam.
Pharmacokinetics and Safety of Ofloxacin in Children with Drug-Resistant Tuberculosis
Authors: Garcia-Prats Anthony J. , Draper Heather R. , Thee Stephanie , Dooley Kelly E. , McIlleron Helen M. , Seddon James A. , Wiesner Lubbe , Castel Sandra , Schaaf H. Simon , Hesseling Anneke C.
Published: July 2015

Ofloxacin is widely used for the treatment of multidrug-resistant tuberculosis (MDR-TB). Data on its pharmacokinetics and safety in children are limited. It is not known whether the current internationally recommended pediatric dosage of 15 to 20 mg/kg of body weight achieves exposures reached in adults with tuberculosis after a standard 800-mg dose (adult median area under the concentration-time curve from 0 to 24 h [AUC
0–24
], 103 μg · h/ml). We assessed the pharmacokinetics and safety of ofloxacin in children <15 years old routinely receiving ofloxacin for MDR-TB treatment or preventive therapy. Plasma samples were collected predose and at 1, 2, 4, 8, and either 6 or 11 h after a 20-mg/kg dose. Pharmacokinetic parameters were calculated using noncompartmental analysis. Children with MDR-TB disease underwent long-term safety monitoring. Of 85 children (median age, 3.4 years), 11 (13%) were HIV infected, and of 79 children with evaluable data, 14 (18%) were underweight. The ofloxacin mean (range) maximum concentration (
C
max
), AUC
0–8
, and half-life were 8.97 μg/ml (2.47 to 14.4), 44.2 μg · h/ml (12.1 to 75.8), and 3.49 h (1.89 to 6.95), respectively. The mean AUC
0–24
, estimated in 72 participants, was 66.7 μg · h/ml (range, 18.8 to 120.7). In multivariable analysis, AUC
0–24
was increased by 1.46 μg · h/ml for each 1-kg increase in body weight (95% confidence interval [CI], 0.44 to 2.47;
P
= 0.006); no other assessed variable contributed to the model. No grade 3 or 4 events at least possibly attributed to ofloxacin were observed. Ofloxacin was safe and well tolerated in children with MDR-TB, but exposures were well below reported adult values, suggesting that dosage modification may be required to optimize MDR-TB treatment regimens in children.
Plasma Tenofovir, Emtricitabine, and Rilpivirine and Intracellular Tenofovir Diphosphate and Emtricitabine Triphosphate Pharmacokinetics following Drug Intake Cessation
Authors: Dickinson Laura , Yapa H. Manisha , Jackson Akil , Moyle Graeme , Else Laura , Amara Alieu , Khoo Saye , Back David , Karolia Zeenat , Higgs Chris , Boffito Marta
Published: July 2015

Pharmacokinetic (PK) data describing a prolonged time course of antiretrovirals in plasma and peripheral blood mononuclear cells (PBMCs) are important for understanding and managing late or missed doses and to assess the appropriateness of compounds for preexposure prophylaxis (PrEP). This study aimed to evaluate the PK of coformulated tenofovir disoproxil fumarate (DF), emtricitabine, and rilpivirine in plasma and of the intracellular (IC) anabolites tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) in healthy volunteers up to 9 days after drug cessation. Individuals received daily tenofovir DF-emtricitabine-rilpivirine (245/200/25 mg) for 14 days. Drug intake was stopped, and serial sampling occurred prior to the final dose and up to 216 h (9 days) after stopping drug intake. Concentrations were quantified and PK parameters calculated. Eighteen volunteers completed the study. The terminal elimination plasma half-lives for tenofovir and emtricitabine over 216 h (geometric mean [90% confidence interval]) were higher than those seen over 0 to 24 h (for tenofovir, 31 h [27 to 40 h] versus 13.3 h [12.5 to 15.1 h]; for emtricitabine, 41 h [36 to 54 h] versus 6.4 h (5.9 to 7.6 h]). Model-predicted IC half-lives (0 to 168 h) were 116 h (TFV-DP) and 37 h (FTC-TP). The plasma rilpivirine concentration at 216 h was 4.5 ng/ml (4.2 to 6.2 ng/ml), and half-lives over 0 to 216 h and 0 to 24 h were 47 h (41 to 59 h) and 35 h (28 to 46 h), respectively. These data contribute to our understanding of drug behavior following treatment interruption; however, adherence to therapy should be promoted. Validated plasma and IC target concentrations are necessary to allow interpretation with respect to sustained virus suppression or HIV prevention. (The trial was conducted in accordance with the Declaration of Helsinki [EudraCT 2012-002781-13].)
Toxic Profile of Benznidazole in Patients with Chronic Chagas Disease: Risk Factors and Comparison of the Product from Two Different Manufacturers
Authors: Molina I. , Salvador F. , Sánchez-Montalvá A. , Treviño B. , Serre N. , Sao Avilés A. , Almirante B.
Published: July 2015

Benznidazole is considered the first-line treatment option against Chagas disease. The major drawback of benznidazole is its toxicity profile. The main objectives of this study were to describe the adverse events (AEs) in patients with chronic Chagas disease treated with benznidazole, determine the risk factors involved and compare the toxic profiles of two different preparations of the drug from ELEA and Roche. A total of 746 patients were diagnosed with Chagas disease in a 5-year period, and of these 472 were treated with benznidazole. A high proportion of patients (
n
= 360 [76%]) suffered AEs, the most frequent being those related to hypersensitivity (52.9% of patients), headache (12.5%), and epigastric pain (10.4%). In 72 (12.7%) cases, treatment was discontinued. Overall, women had a higher incidence of AEs compared to men (81.3% versus 66%,
P
= 0.001) and were subject to higher levels of hypersensitivity-related events. Dermatological events, digestive tract manifestations, and general symptoms had a greater likelihood to appear around day 10 and neurological AEs around day 40 after starting treatment. With respect to liver function and hematological tests, the majority of patients did not suffer significant perturbation of liver enzymes or altered blood cell counts. However, 14 patients suffered from neutropenia, and 14 patients had aminotransferase levels that were more than four times the upper limit of the normal range. Patients treated with the ELEA benznidazole product experienced more arthromyalgia, neutropenia, and neurological disorders (mainly paresthesias) than those treated with the Roche product. Both drug products resulted in approximately the same percentage of permanent withdrawals.
Genetically Engineering Bacillus subtilis with a Heat-Resistant Arsenite Methyltransferase for Bioremediation of Arsenic-Contaminated Organic Waste
Authors: Huang Ke , Chen Chuan , Shen Qirong , Rosen Barry P. , Zhao Fang-Jie
Published: July 2015

Organic manures may contain high levels of arsenic (As) due to the use of As-containing growth-promoting substances in animal feed. To develop a bioremediation strategy to remove As from organic waste,
Bacillus subtilis
168, a bacterial strain which can grow at high temperature but is unable to methylate and volatilize As, was genetically engineered to express the arsenite
S
-adenosylmethionine methyltransferase gene (
CmarsM
) from the thermophilic alga
Cyanidioschyzon merolae
. The genetically engineered
B. subtilis
168 converted most of the inorganic As in the medium into dimethylarsenate and trimethylarsine oxide within 48 h and volatized substantial amounts of dimethylarsine and trimethylarsine. The rate of As methylation and volatilization increased with temperature from 37 to 50°C. When inoculated into an As-contaminated organic manure composted at 50°C, the modified strain significantly enhanced As volatilization. This study provides a proof of concept of using genetically engineered microorganisms for bioremediation of As-contaminated organic waste during composting.
Bacterial Cyanuric Acid Hydrolase for Water Treatment
Authors: Yeom Sujin , Mutlu Baris R. , Aksan Alptekin , Wackett Lawrence P.
Published: July 2015

Di- and trichloroisocyanuric acids are widely used as water disinfection agents, but cyanuric acid accumulates with repeated additions and must be removed to maintain free hypochlorite for disinfection. This study describes the development of methods for using a cyanuric acid-degrading enzyme contained within nonliving cells that were encapsulated within a porous silica matrix. Initially, three different bacterial cyanuric acid hydrolases were compared: TrzD from
Acidovorax citrulli
strain 12227, AtzD from
Pseudomonas
sp. strain ADP, and CAH from
Moorella thermoacetica
ATCC 39073. Each enzyme was expressed recombinantly in
Escherichia coli
and tested for cyanuric acid hydrolase activity using freely suspended or encapsulated cell formats. Cyanuric acid hydrolase activities differed by only a 2-fold range when comparing across the different enzymes with a given format. A practical water filtration system is most likely to be used with nonviable cells, and all cells were rendered nonviable by heat treatment at 70°C for 1 h. Only the CAH enzyme from the thermophile
M. thermoacetica
retained significant activity under those conditions, and so it was tested in a flowthrough system simulating a bioreactive pool filter. Starting with a cyanuric acid concentration of 10,000 μM, more than 70% of the cyanuric acid was degraded in 24 h, it was completely removed in 72 h, and a respike of 10,000 μM cyanuric acid a week later showed identical biodegradation kinetics. An experiment conducted with water obtained from municipal swimming pools showed the efficacy of the process, although cyanuric acid degradation rates decreased by 50% in the presence of 4.5 ppm hypochlorite. In total, these experiments demonstrated significant robustness of cyanuric acid hydrolase and the silica bead materials in remediation.
Expression, Purification, and Biological Characterization of Babesia microti Apical Membrane Antigen 1
Authors: Moitra Prasun , Zheng Hong , Anantharaman Vivek , Banerjee Rajdeep , Takeda Kazuyo , Kozakai Yukiko , Lepore Timothy , Krause Peter J. , Aravind L. , Kumar Sanjai
Published: July 2015

The intraerythrocytic apicomplexanBabesia microti, the primary causative agent of human babesiosis, is a major public health concern in the United States and elsewhere. Apicomplexans utilize a multiprotein complex that includes a type I membrane protein called apical membrane antigen 1 (AMA1) to invade host cells. We have isolated the full-lengthB. microtiAMA1 (BmAMA1) gene and determined its nucleotide sequence, as well as the amino acid sequence of the AMA1 protein. This protein contains an N-terminal signal sequence, an extracellular region, a transmembrane region, and a short conserved cytoplasmic tail. It shows the same domain organization as the AMA1 orthologs from piroplasm, coccidian, and haemosporidian apicomplexans but differs from all other currently known piroplasmida, including otherBabesiaandTheileriaspecies, in lacking two conserved cysteines in highly variable domain III of the extracellular region. Minimal polymorphism was detected in BmAMA1 gene sequences of parasite isolates from six babesiosis patients from Nantucket. Immunofluorescence microscopy studies showed that BmAMA1 is localized on the cell surface and cytoplasm near the apical end of the parasite. Native BmAMA1 from parasite lysate and refolded recombinant BmAMA1 (rBmAMA1) expressed inEscherichia colireacted with a mouse anti-BmAMA1 antibody using Western blotting.In vitrobinding studies showed that both native BmAMA1 and rBmAMA1 bind to human red blood cells (RBCs). This binding is trypsin and chymotrypsin treatment sensitive but neuraminidase independent. Incubation ofB. microtiparasites in human RBCs with a mouse anti-BmAMA1 antibody inhibited parasite growth by 80% in a 24-h assay. Based on its antigenically conserved nature and potential role in RBC invasion, BmAMA1 should be evaluated as a vaccine candidate.
The O-Antigen Capsule of Salmonella enterica Serovar Typhimurium Facilitates Serum Resistance and Surface Expression of FliC
Authors: Marshall Joanna M. , Gunn John S.
Published: July 2015

Group IV polysaccharide capsules are common in enteric bacteria and have more recently been described in nontyphoidal
Salmonella
species. Such capsules are known as O-antigen (O-Ag) capsules, due to their high degree of similarity to the O-Ag of the lipopolysaccharide (LPS
O-Ag
). Capsular polysaccharides are known virulence factors of many bacterial pathogens, facilitating evasion of immune recognition and systemic dissemination within the host. Previous studies on the O-Ag capsule of salmonellae have focused primarily on its role in bacterial surface attachment and chronic infection; however, the potential effects of the O-Ag capsule on acute pathogenesis have yet to be investigated. While much of the
in vivo
innate immune resistance of
Salmonella enterica
serovar Typhimurium is attributed to the high-molecular-weight LPS, we hypothesized that the O-Ag capsule may enhance this resistance by diminishing surface expression of pathogen-associated molecular patterns, such as flagella, and increasing resistance to host immune molecules. To test this hypothesis, O-Ag capsule-deficient mutants were constructed, and the loss of O-Ag capsular surface expression was confirmed through microscopy and immunoblotting. Loss of O-Ag capsule production did not alter bacterial growth or production of LPS. Western blot analysis and confocal microscopy revealed that O-Ag capsule-deficient mutants demonstrate reduced resistance to killing by human serum. Furthermore, O-Ag capsule-deficient mutants produced exclusively phase I flagellin (FliC). Although O-Ag capsule-deficient mutants did not exhibit reduced virulence in a murine model of acute infection,
in vitro
results indicate that the O-Ag capsule may function to modify the antigenic nature of the bacterial surface, warranting additional investigation of a potential role of the structure in pathogenesis.
Choriodecidual Group B Streptococcal Infection Induces miR-155-5p in the Fetal Lung in Macaca nemestrina
Authors: McAdams Ryan M. , Bierle Craig J. , Boldenow Erica , Weed Samantha , Tsai Jesse , Beyer Richard P. , MacDonald James W. , Bammler Theo K. , Liggitt H. Denny , Farin Federico M. , Vanderhoeven Jeroen , Rajagopal Lakshmi , Adams Waldorf Kristina M.
Published: July 2015

The mechanisms underlying fetal lung injury remain poorly defined. MicroRNAs (miRNAs) are small noncoding, endogenous RNAs that regulate gene expression and have been implicated in the pathogenesis of lung disease. Using a nonhuman primate model of choriodecidual infection, we sought to determine if differentially expressed miRNAs were associated with acute fetal lung injury. After inoculating 10 chronically catheterized pregnant monkeys (
Macaca nemestrina
) with either group B streptococcus (GBS) at 1 × 10
6
CFU (
n
= 5) or saline (
n
= 5) in the choriodecidual space, we extracted fetal lung mRNA and miRNA and profiled the changes in expression by microarray analysis. We identified 9 differentially expressed miRNAs in GBS-exposed fetal lungs, but of these, only miR-155-5p was validated by quantitative reverse transcription-PCR (
P
= 0.02). Significantly elevated miR-155-5p expression was also observed when immortalized human fetal airway epithelial (FeAE) cells were exposed to proinflammatory cytokines (interleukin-6 [IL-6] and tumor necrosis factor alpha [TNF-α]). Overexpression of miR-155-5p in FeAE cells in turn increased the production of IL-6 and CXCL10/gamma interferon-induced protein 10, which are implicated in leukocyte recruitment but also in protection from lung injury. Interestingly, while miR-155-5p decreased fibroblast growth factor 9 (FGF9) expression in a luciferase reporter assay, FGF9 levels were actually increased in GBS-exposed fetal lungs
in vivo
. FGF9 overexpression is associated with abnormal lung development. Thus, upregulation of miR-155-5p may serve as a compensatory mechanism to lessen the increase in FGF9 and prevent aberrant lung development. Understanding the complicated networks regulating lung development in the setting of infection is a key step in identifying how to prevent fetal lung injury leading to bronchopulmonary dysplasia.
The Legionella pneumophila Siderophore Legiobactin Is a Polycarboxylate That Is Identical in Structure to Rhizoferrin
Authors: Burnside Denise M. , Wu Yuyang , Shafaie Saman , Cianciotto Nicholas P.
Published: July 2015

Legionella pneumophila, the agent of Legionnaires' disease, secretes a siderophore (legiobactin) that promotes bacterial infection of the lung. In past work, we determined that cytoplasmic LbtA (fromLegiobactin geneA) promotes synthesis of legiobactin, inner membrane LbtB aids in export of the siderophore, and outer membrane LbtU and inner membrane LbtC help mediate ferrilegiobactin uptake and assimilation. However, the past studies examined legiobactin contained within bacterial culture supernatants. By utilizing high-pressure liquid chromatography that incorporates hydrophilic interaction-based chemistry, we have now purified legiobactin from supernatants of virulent strain 130b that is suitable for detailed chemical analysis. High-resolution mass spectrometry (MS) revealed that the molecular mass of (protonated) legiobactin is 437.140 Da. On the basis of the results obtained from both MS analysis and various forms of nuclear magnetic resonance, we found that legiobactin is composed of two citric acid residues linked by a putrescine bridge and thus is identical in structure to rhizoferrin, a polycarboxylate-type siderophore made by many fungi and several unrelated bacteria. Both purified legiobactin and rhizoferrin obtained from the fungusCunninghamella eleganswere able to promote Fe3+uptake by wild-typeL. pneumophilaas well as enhance growth of iron-starved bacteria. These results did not occur with 130b mutants lackinglbtUorlbtC, indicating that both endogenously made legiobactin and exogenously derived rhizoferrin are assimilated byL. pneumophilain an LbtU- and LbtC-dependent manner.
Candida albicans Quorum Sensing Molecules Stimulate Mouse Macrophage Migration
Authors: Hargarten Jessica C. , Moore Tyler C. , Petro Thomas M. , Nickerson Kenneth W. , Atkin Audrey L.
Published: July 2015

The polymorphic commensal fungusCandida albicanscauses life-threatening disease via bloodstream and intra-abdominal infections in immunocompromised and transplant patients. Although host immune evasion is a common strategy used by successful human fungal pathogens,C. albicansprovokes recognition by host immune cells less capable of destroying it. To accomplish this,C. albicanswhite cells secrete a low-molecular-weight chemoattractive stimulant(s) of macrophages, a phagocyte that they are able to survive within and eventually escape from.C. albicansopaque cells do not secrete this chemoattractive stimulant(s). We report here a physiological mechanism that contributes to the differences in the interaction ofC. albicanswhite and opaque cells with macrophages.E,E-Farnesol, which is secreted by white cells only, is a potent stimulator of macrophage chemokinesis, whose activity is enhanced by yeast cell wall components and aromatic alcohols.E,E-farnesol results in up to an 8.5-fold increase in macrophage migrationin vitroand promotes a 3-fold increase in the peritoneal infiltration of macrophagesin vivo. Therefore, modulation of farnesol secretion to stimulate host immune recognition by macrophages may help explain why this commensal is such a successful pathogen.
The Poly-γ-d-Glutamic Acid Capsule Surrogate of the Bacillus anthracis Capsule Is a Novel Toll-Like Receptor 2 Agonist
Authors: Jeon Jun Ho , Lee Hae-Ri , Cho Min-Hee , Park Ok-Kyu , Park Jungchan , Rhie Gi-eun
Published: July 2015

Bacillus anthracisis a pathogenic Gram-positive bacterium that causes a highly lethal infectious disease, anthrax. The poly-γ-d-glutamic acid (PGA) capsule is one of the major virulence factors ofB. anthracis, along with exotoxins. PGA enablesB. anthracisto escape phagocytosis and immune surveillance. Our previous study showed that PGA activates the human macrophage cell line THP-1 and human dendritic cells, resulting in the production of the proinflammatory cytokine interleukin-1β (IL-1β) (M. H. Cho et al., Infect Immun 78:387–392, 2010,http://dx.doi.org/10.1128/IAI.00956-09). Here, we investigated PGA-induced cytokine responses and related signaling pathways in mouse bone marrow-derived macrophages (BMDMs) usingBacillus licheniformisPGA as a surrogate forB. anthracisPGA. Upon exposure to PGA, BMDMs produced proinflammatory mediators, including tumor necrosis factor alpha (TNF-α), IL-6, IL-12p40, and monocyte chemoattractant protein 1 (MCP-1), in a concentration-dependent manner. PGA stimulated Toll-like receptor 2 (TLR2) but not TLR4 in Chinese hamster ovary cells expressing either TLR2 or TLR4. The ability of PGA to induce TNF-α and IL-6 was retained in TLR4−/−but not TLR2−/−BMDMs. Blocking experiments with specific neutralizing antibodies for TLR1, TLR6, and CD14 showed that TLR6 and CD14 also were necessary for PGA-induced inflammatory responses. Furthermore, PGA enhanced activation of mitogen-activated protein (MAP) kinases and nuclear factor-kappa B (NF-κB), which are responsible for expression of proinflammatory cytokines. Additionally, PGA-induced TNF-α production was abrogated not only in MyD88−/−BMDMs but also in BMDMs pretreated with inhibitors of MAP kinases and NF-κB. These results suggest that immune responses induced by PGA occur via TLR2, TLR6, CD14, and MyD88 through activation of MAP kinase and NF-κB pathways.
RecF and RecR Play Critical Roles in the Homologous Recombination and Single-Strand Annealing Pathways of Mycobacteria
Authors: Gupta Richa , Shuman Stewart , Glickman Michael S.
Published: July 2015

Mycobacteria encode three DNA double-strand break repair pathways: (i) RecA-dependent homologous recombination (HR), (ii) Ku-dependent nonhomologous end joining (NHEJ), and (iii) RecBCD-dependent single-strand annealing (SSA). Mycobacterial HR has two presynaptic pathway options that rely on the helicase-nuclease AdnAB and the strand annealing protein RecO, respectively. Ablation of
adnAB
or
recO
individually causes partial impairment of HR, but loss of
adnAB
and
recO
in combination abolishes HR. RecO, which can accelerate annealing of single-stranded DNA
in vitro
, also participates in the SSA pathway. The functions of RecF and RecR, which, in other model bacteria, function in concert with RecO as mediators of RecA loading, have not been examined in mycobacteria. Here, we present a genetic analysis of
recF
and
recR
in mycobacterial recombination. We find that RecF, like RecO, participates in the AdnAB-independent arm of the HR pathway and in SSA. In contrast, RecR is required for all HR in mycobacteria and for SSA. The essentiality of RecR as an agent of HR is yet another distinctive feature of mycobacterial DNA repair.

IMPORTANCE
This study clarifies the molecular requirements for homologous recombination in mycobacteria. Specifically, we demonstrate that RecF and RecR play important roles in both the RecA-dependent homologous recombination and RecA-independent single-strand annealing pathways. Coupled with our previous findings (R. Gupta, M. Ryzhikov, O. Koroleva, M. Unciuleac, S. Shuman, S. Korolev, and M. S. Glickman, Nucleic Acids Res 41:2284–2295, 2013,
http://dx.doi.org/10.1093/nar/gks1298
), these results revise our view of mycobacterial recombination and place the RecFOR system in a central position in homology-dependent DNA repair.
Function of the Histone-Like Protein H-NS in Motility of Escherichia coli: Multiple Regulatory Roles Rather than Direct Action at the Flagellar Motor
Authors: Kim Eun A , Blair David F.
Published: July 2015

A number of investigations of
Escherichia coli
have suggested that the DNA-binding protein H-NS, in addition to its well-known functions in chromosome organization and gene regulation, interacts directly with the flagellar motor to modulate its function. Here, in a study initially aimed at characterizing the H-NS/motor interaction further, we identify problems and limitations in the previous work that substantially weaken the case for a direct H-NS/motor interaction. Null
hns
mutants are immotile, largely owing to the downregulation of the flagellar master regulators FlhD and FlhC. We, and others, previously reported that an
hns
mutant remains poorly motile even when FlhDC are expressed constitutively. In the present work, we use better-engineered strains to show that the motility defect in a Δ
hns
, FlhDC-constitutive strain is milder than that reported previously and does not point to a direct action of H-NS at the motor. H-NS regulates numerous genes and might influence motility via a number of regulatory molecules besides FlhDC. To examine the sources of the motility defect that persists in an FlhDC-constitutive Δ
hns
mutant, we measured transcript levels and overexpression effects of a number of genes in candidate regulatory pathways. The results indicate that H-NS influences motility via multiple regulatory linkages that include, minimally, the messenger molecule cyclic di-GMP, the biofilm regulatory protein CsgD, and the sigma factors σ
S
and σ
F
. The results are in accordance with the more standard view of H-NS as a regulator of gene expression rather than a direct modulator of flagellar motor performance.

IMPORTANCE
Data from a number of previous studies have been taken to indicate that the nucleoid-organizing protein H-NS influences motility not only by its well-known DNA-based mechanisms but also by binding directly to the flagellar motor to alter function. In this study, H-NS is shown to influence motility through diverse regulatory pathways, but a direct interaction with the motor is not supported. Previous indications of a direct action at the motor appear to be related to the use of nonnull strains and, in some cases, a failure to effectively bypass the requirement for H-NS in the expression of the flagellar regulon. These findings call for a substantially revised interpretation of the literature concerning H-NS and flagellar motility and highlight the importance of H-NS in diverse regulatory processes involved in the motile-sessile transition.
Lessons in Fundamental Mechanisms and Diverse Adaptations from the 2015 Bacterial Locomotion and Signal Transduction Meeting
Authors: Prüβ Birgit M. , Liu Jun , Higgs Penelope I. , Thompson Lynmarie K.
Published: July 2015

In response to rapid changes in their environment, bacteria control a number of processes, including motility, cell division, biofilm formation, and virulence. Research presented in January 2015 at the biennial Bacterial Locomotion and Signal Transduction (BLAST) meeting in Tucson, AZ, illustrates the elegant complexity of the nanoarrays, nanomachines, and networks of interacting proteins that mediate such processes. Studies employing an array of biophysical, genetic, cell biology, and mathematical methods are providing an increasingly detailed understanding of the mechanisms of these systems within well-studied bacteria. Furthermore, comparisons of these processes in diverse bacterial species are providing insight into novel regulatory and functional mechanisms. This review summarizes research presented at the BLAST meeting on these fundamental mechanisms and diverse adaptations, including findings of importance for applications involving bacteria of medical or agricultural relevance.
CutaneousCryptococcus: marker for disseminated infection
Authors: Srivastava G N , Tilak Ragini , Yadav Jyoti , Bansal Manish
Published: July 2015

Cryptococcosis is an infection caused by the encapsulated yeast,Cryptococcus neoformans, a dimorphic fungus recovered from pigeon excreta, soil, dust and human skin. After a primary infection in the lungs, the disease can disseminate via a haematogenous route to various organs, including the central nervous system and skin, in susceptible individuals. Cryptococcosis can present with a variety of skin and soft tissue manifestations including acneiform lesions, purpura, vesicles, nodules, abscesses, ulcers, granulomas, pustules, draining sinuses and cellulitis. We present a case of a young man with HIV infection who developed molluscum-like cutaneous lesions secondary to pulmonary cryptococcosis. The diagnosis was confirmed by Indian ink preparation of the cutaneous lesions. Primary cutaneous infection occurs rarely due to direct inoculation. Cutaneous lesions are usually secondary and act as a key marker of disseminated infection, especially in patients with impaired cell-mediated immunity, such as those infected with HIV, solid-organ transplant recipients, and those on chronic corticosteroid therapy.
Laser treatment of macular retinoschisis due to acquired optic nerve pit from glaucoma
Authors: Prinzi Robert A , Desai Ankit , Gao Hua
Published: July 2015

Macular retinoschisis can be caused by acquired optic nerve pit from glaucoma. This study evaluated the efficacy of laser treatment for this disorder. We report on five eyes from three patients with macular retinoschisis and a history of glaucoma. Spectral domain optical coherence tomography was used for diagnosis and follow-up. Treatment was performed with barrier laser on the temporal margin of the optic nerve. Following treatment, patients’ average vision improved by 1 line on the Snellen chart at average follow-up of 12.3 months. All five eyes showed significant improvement in macular retinoschisis. The tracts connecting the optic pit to the retinoschisis completely closed in three eyes and nearly closed in two eyes. These cases demonstrate that laser photocoagulation is an effective treatment of macular retinoschisis from acquired optic nerve pit. It can serve as first-line treatment before more invasive options such as vitrectomy are considered.
Injury risk is low among world-class volleyball players: 4-year data from the FIVB Injury Surveillance System
Authors: Bere Tone , Kruczynski Jacek , Veintimilla Nadège , Hamu Yuichiro , Bahr Roald
Published: July 2015

Background

Little is known about the rate and pattern of injuries in international volleyball competition.

Objective

To describe the risk and pattern of injuries among world-class players based on data from the The International Volleyball Federation (FIVB) Injury Surveillance System (ISS) (junior and senior, male and female).

Methods

The FIVB ISS is based on prospective registration of injuries by team medical staff during all major FIVB tournaments (World Championships, World Cup, World Grand Prix, World League, Olympic Games). This paper is based on 4-year data (September 2010 to November 2014) obtained through the FIVB ISS during 32 major FIVB events (23 senior and 9 junior).

Results

The incidence of time-loss injuries during match play was 3.8/1000 player hours (95% CI 3.0 to 4.5); this was greater for senior players than for junior players (relative risk: 2.04, 1.29 to 3.21), while there was no difference between males and females (1.04, 0.70 to 1.55). Across all age and sex groups, the ankle was the most commonly injured body part (25.9%), followed by the knee (15.2%), fingers/thumb (10.7%) and lower back (8.9%). Injury incidence was greater for centre players and lower for liberos than for other player functions; injury patterns also differed between player functions.

Conclusions

Volleyball is a very safe sport, even at the highest levels of play. Preventive measures should focus on acute ankle and finger sprains, and overuse injuries in the knee, lower back and shoulder.
Mitosin and pHH3 predict poorer survival in astrocytomas WHO grades II and III
Authors: Varughese R K , Lind-Landström T , Habberstad A H , Salvesen Ø , Haug C S , Sundstrøm S , Torp S H
Published: July 2015

Aims:

The limitations of the current WHO classification of astrocytomas call for a sustained effort to improve diagnostic and prognostic accuracy. The relationship between tumour growth and clinical outcome suggests that proliferative activity should be examined. The objective of this study was to evaluate the diagnostic and prognostic value of the proliferation markers mitosin and phosphohistone H3 (pHH3) in infiltrative astrocytomas WHO grades II and III and compare the findings with mitotic count and Ki-67/MiB-1 immunostaining.

Methods:

Fifty-nine and thirty-three infiltrative astrocytomas WHO grades II and III, respectively, were immunostained with the proliferation markers mitosin and pHH3 using standard immunohistochemical procedures. The expression was quantified as a proliferative index (PI) and statistically evaluated with Spearman's rank correlation test, Wilcoxon-Mann-Whitney U test, and univariable and multivariable COX regression survival analyses.

Results:

Significant positive correlations were found between these proliferation markers. The number of mitoses, pHH3 mitotic figures (MFs), the Ki-67/MiB-1 PI and the mitosin PI were greater in WHOgrade III anaplastic astrocytomas compared to WHO grade II diffuse astrocytomas, while pHH3 PI only showed a trend. All proliferation markers were associated with poorer prognosis, but mitotic count was not. Ki-67/MiB-1, mitosin and pHH3 MF achieved statistical significance in the univariable analyses of both time to relapse (TTR) and overall survival (OS). Only mitosin remained significant in both multivariable analyses. pHH3 was significant in the multivariable analysis of OS but not of TTR. Clinical factors including age, extent of surgical resection and WHO performance status were also significantly correlated with survival.

Conclusions:

In conclusion, mitosin and pHH3 immunostaining have prognostic and diagnostic value in the clinical assessment of patients with infiltrative astrocytomas. The inclusion of proliferation markers in a layered diagnosis should be considered in the upcoming revision of the WHO classification system.
EBV-related primary splenic lymphocyte-depleted classical Hodgkin lymphoma
Authors: Parekh Vishwas , Peker Deniz
Published: July 2015

Lymphocyte-depleted classical Hodgkin lymphoma (LDCHL) is the rarest entity among the classical Hodgkin lymphoma (CHL) subtypes, accounting for <1% of CHL cases in Western countries. Similarly, primary splenic Hodgkin lymphoma is a rare diagnosis among all cases of lymphomatous involvement of spleen. Representing a combination of these two rare entities is the primary splenic LDCHL, with only one case reported in the literature. Here, we report second case of primary splenic LDCHL with a unique presentation. The patient was a 60-year-old Caucasian HIV-negative woman with a history of extranodal pleuropulmonary marginal zone lymphoma (MZL) treated with rituximab who presented with new-onset splenomegaly. Splenectomy revealed large number of Hodgkin/Reed–Sternberg cells (CD15+, CD30+, PAX5+ and EBER+) with the background consisting of histiocytes and smaller number of lymphocytes and eosinophils. There was no evidence of nodal or other extranodal site involvement. Thus, in addition to being a very rare entity, this case also provides an additional point of interest: the disease arose in the backdrop of previous diagnosis of extranodal pleuropulmonary MZL successfully treated with rituximab. We discuss the potential implications.
Autoinflammatory granulomatous diseases: from Blau syndrome and early-onset sarcoidosis to NOD2-mediated disease and Crohn's disease
Authors: Caso Francesco , Galozzi Paola , Costa Luisa , Sfriso Paolo , Cantarini Luca , Punzi Leonardo
Published: July 2015

The recent identification of genetic mutations leading to dysfunction of inflammatory and apoptotic pathways, has allowed to characterise a group of diseases, recognised as monogenic autoinflammatory syndromes. Among those, Blau syndrome (BS) and early-onset sarcoidosis (EOS) have been identified as familial and sporadic phenotypes of the same non-caseating granulomatous form. Both the diseases are caused by mutations in theCARD15/NOD2gene, encoding the cytosolic NOD2 protein, one of the key molecules in the regulation of innate immunity. Clinical onset is typically located in the first years of life and phenotype is characterised by simultaneous or less articular, cutaneous and ocular non-caseating granulomatous inflammation, which can be variably associated with a heterogeneous systemic spectrum. TheCARD15/NOD2gene has also been identified as one of the genes linked to susceptibility to Crohn's disease (CD), a common polygenic inflammatory granulomatous bowel disease. The heightened nuclear factor-κB activity, found in the intestinal tissue of patients affected by CD, has probably a genetic cause related to severalCARD15/NOD2polymorphisms. Other substitutions in theCARD15/NOD2gene have also been found in a recently described disorder, calledNOD2-associated autoinflammatory disease, which shares several clinical characteristics with BS and EOS. This review attempts to describe these diseases on the basis of the most recent evidences. We described genetic and clinical aspects, mainly focusing on BS and EOS, the most representative diseases of autoinflammatory granulomatous diseases, with the ultimate purpose to expand their knowledge.
Unified and simple derivation of energy levels for the Pöschl–Teller-type and Scarf-type potentials
Authors: Benchiheub Nadjet , Kasri Yazid , Kahoul Abdelhalim
Published: July 2015

A general class of potentials covering the Pöschl–Teller-type and Scarf-type is considered. The analytical expression of the energy eigenvalues is established with the help of the exact quantization formula. Then, using appropriate coordinate transformations, the exact spectrums of five well-known potentials: Pöschl–Teller, Pöschl–Teller I and Pöschl–Teller II, Scarf I, and Scarf II, are deduced in a simple way.