bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transfer Efficiency of Bacteria and Viruses from Porous and Nonporous Fomites to Fingers under Different Relative Humidity Conditions
Authors: Lopez Gerardo U. , Gerba Charles P. , Tamimi Akrum H. , Kitajima Masaaki , Maxwell Sheri L. , Rose Joan B. 
Published: July 2013

ABSTRACTFomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (fomites). Nine fomites representing porous and nonporous surfaces of different compositions were studied.Escherichia coli,Staphylococcus aureus,Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm2of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (<6.8%) under low relative humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from fomite-transmitted human pathogens and the relative levels of exposure to different types of fomites and microorganisms.
Identification and Characterization of a NaCl-Responsive Genetic Locus Involved in Survival during Desiccation in Sinorhizobium meliloti
Authors: Vriezen Jan A. C. , de Bruijn Frans J. , Nüsslein Klaus 
Published: July 2013

ABSTRACT

The
Rhizobiaceae
are a bacterial family of enormous agricultural importance due to the ability of its members to fix atmospheric nitrogen in an intimate relationship with plants. Their survival as naturally occurring soil bacteria in agricultural soils as well as popular seed inocula is affected directly by drought and salinity. Survival after desiccation in the presence of NaCl is enabled by underlying genetic mechanisms in the model organism
Sinorhizobium meliloti
1021. Since salt stress parallels a loss in water activity, the identification of NaCl-responsive loci may identify loci involved in survival during desiccation. This approach enabled identification of the loci
asnO
and
ngg
by their reduced ability to grow on increased NaCl concentrations, likely due to their inability to produce the osmoprotectant N-acetylglutaminylglutamine (NAGGN). In addition, the mutant harboring
ngg
::Tn
5luxAB
was affected in its ability to survive desiccation and responded to osmotic stress. The desiccation sensitivity may have been due to secondary functions of Ngg (N-acetylglutaminylglutamine synthetase)-like cell wall metabolism as suggested by the presence of a
d
-alanine-
d
-alanine ligase (dAla-dAla) domain and by sensitivity of the mutant to β-lactam antibiotics.
asnO
::Tn
5luxAB
is expressed during the stationary phase under normal growth conditions. Amino acid sequence similarity to enzymes producing β-lactam inhibitors and increased resistance to β-lactam antibiotics may indicate that
asnO
is involved in the production of a β-lactam inhibitor.
New Type of Antimicrobial Protein Produced by the Plant Pathogen Clavibacter michiganensis subsp. michiganensis
Authors: Liu Zhanliang , Ma Ping , Holtsmark Ingrid , Skaugen Morten , Eijsink Vincent G. H. , Brurberg May B. 
Published: July 2013

ABSTRACT

It has previously been shown that the tomato pathogen
Clavibacter michiganensis
subsp.
michiganensis
secretes a 14-kDa protein,
C. michiganensis
subsp.
michiganensis
AMP-I (
Cmm
AMP-I), that inhibits growth of
Clavibacter michiganensis
subsp.
sepedonicus
, the causal agent of bacterial ring rot of potato. Using sequences obtained from tryptic fragments, we have identified the gene encoding
Cmm
AMP-I and we have recombinantly produced the protein with an N-terminal intein tag. The gene sequence showed that
Cmm
AMP-I contains a typical N-terminal signal peptide for Sec-dependent secretion. The recombinant protein was highly active, with 50% growth inhibition (IC
50
) of approximately 10 pmol, but was not toxic to potato leaves or tubers.
Cmm
AMP-I does not resemble any known protein and thus represents a completely new type of bacteriocin. Due to its high antimicrobial activity and its very narrow inhibitory spectrum,
Cmm
AMP-1 may be of interest in combating potato ring rot disease.
Shared Mycobacterium avium Genotypes Observed among Unlinked Clinical and Environmental Isolates
Authors: Dirac M. Ashworth , Weigel Kris M. , Yakrus Mitchell A. , Becker Annie L. , Chen Hui-Ling , Fridley Gina , Sikora Arthur , Speake Cate , Hilborn Elizabeth D. , Pfaller Stacy , Cangelosi Gerard A. 
Published: July 2013

ABSTRACT

Our understanding of the sources of
Mycobacterium avium
infection is partially based on genotypic matching of pathogen isolates from cases and environmental sources. These approaches assume that genotypic identity is rare in isolates from unlinked cases or sources. To test this assumption, a high-resolution PCR-based genotyping approach, large-sequence polymorphism (LSP)-mycobacterial interspersed repetitive unit–variable-number tandem repeat (MIRU-VNTR), was selected and used to analyze clinical and environmental isolates of
M. avium
from geographically diverse sources. Among 127 clinical isolates from seven locations in North America, South America, and Europe, 42 genotypes were observed. Among 12 of these genotypes, matches were seen in isolates from apparently unlinked patients in two or more geographic locations. Six of the 12 were also observed in environmental isolates. A subset of these isolates was further analyzed by alternative strain genotyping methods, pulsed-field gel electrophoresis and MIRU-VNTR, which confirmed the existence of geographically dispersed strain genotypes. These results suggest that caution should be exercised in interpreting high-resolution genotypic matches as evidence for an acquisition event.
Proteolysin, a Novel Highly Thermostable and Cosolvent-Compatible Protease from the Thermophilic Bacterium Coprothermobacter proteolyticus
Authors: Toplak Ana , Wu Bian , Fusetti Fabrizia , Quaedflieg Peter J. L. M. , Janssen Dick B. 
Published: July 2013

ABSTRACT

Through genome mining, we identified a gene encoding a putative serine protease of the thermitase subgroup of subtilases (EC 3.4.21.66) in the thermophilic bacterium
Coprothermobacter proteolyticus
. The gene was functionally expressed in
Escherichia coli
, and the enzyme, which we called proteolysin, was purified to near homogeneity from crude cell lysate by a single heat treatment step. Proteolysin has a broad pH tolerance and is active at temperatures of up to 80°C. In addition, the enzyme shows good activity and stability in the presence of organic solvents, detergents, and dithiothreitol, and it remains active in 6 M guanidinium hydrochloride. Based on its stability and activity profile, proteolysin can be an excellent candidate for applications where resistance to harsh process conditions is required.
Nisin Resistance of Listeria monocytogenes Is Increased by Exposure to Salt Stress and Is Mediated via LiaR
Authors: Bergholz Teresa M. , Tang Silin , Wiedmann Martin , Boor Kathryn J. 
Published: July 2013

ABSTRACTGrowth ofListeria monocytogeneson refrigerated, ready-to-eat food is a significant food safety concern. Natural antimicrobials, such as nisin, can be used to control this pathogen on food, but little is known about how other food-related stresses may impact how the pathogen responds to these compounds. Prior work demonstrated that exposure ofL. monocytogenesto salt stress at 7°C led to increased expression of genes involved in nisin resistance, including the response regulatorliaR. We hypothesized that exposure to salt stress would increase subsequent resistance to nisin and that LiaR would contribute to increased nisin resistance. Isogenic deletion mutations inliaRwere constructed in 7 strains ofL. monocytogenes, and strains were exposed to 6% NaCl in brain heart infusion broth and then tested for resistance to nisin (2 mg/ml Nisaplin) at 7°C. For the wild-type strains, exposure to salt significantly increased subsequent nisin resistance (P< 0.0001) over innate levels of resistance. Compared to the salt-induced nisin resistance of wild-type strains, ΔliaRstrains were significantly more sensitive to nisin (P< 0.001), indicating that induction of LiaFSR led to cross-protection ofL. monocytogenesagainst subsequent inactivation by nisin. Transcript levels of LiaR-regulated genes were induced by salt stress, and lmo1746 andtelAwere found to contribute to LiaR-mediated salt-induced nisin resistance. These data suggest that environmental stresses similar to those on foods can influence the resistance ofL. monocytogenesto antimicrobials such as nisin, and potential cross-protective effects should be considered when selecting and applying control measures for this pathogen on ready-to-eat foods.
Whole-Transcriptome Shotgun Sequencing (RNA-seq) Screen Reveals Upregulation of Cellobiose and Motility Operons of Lactobacillus ruminis L5 during Growth on Tetrasaccharides Derived from Barley β-Glucan
Authors: Lawley Blair , Sims Ian M. , Tannock Gerald W. 
Published: July 2013

ABSTRACT

Lactobacillus ruminis
is an inhabitant of human bowels and bovine rumens. None of 10 isolates (three from bovine rumen, seven from human feces) of
L. ruminis
that were tested could utilize barley β-glucan for growth. Seven of the strains of
L. ruminis
were, however, able to utilize tetrasaccharides (3-
O
-β-cellotriosyl-
d
-glucose [LDP4] or 4-
O
-β-laminaribiosyl-
d
-cellobiose [CDP4]) present in β-glucan hydrolysates for growth. The tetrasaccharides were generated by the use of lichenase or cellulase, respectively. To learn more about the utilization of tetrasaccharides by
L. ruminis
, whole-transcriptome shotgun sequencing (RNA-seq) was tested as a transcriptional screen to detect altered gene expression when an autochthonous human strain (L5) was grown in medium containing CDP4. RNA-seq results were confirmed and extended by reverse transcription-quantitative PCR assays of selected genes in two upregulated operons when cells were grown as batch cultures in medium containing either CDP4 or LDP4. The cellobiose utilization operon had increased transcription, particularly in early growth phase, whereas the chemotaxis/motility operon was upregulated in late growth phase. Phenotypic changes were seen in relation to upregulation of chemotaxis/flagellar operons: flagella were rarely seen by electron microscopy on glucose-grown cells but cells cultured in tetrasaccharide medium were commonly flagellated. Chemotactic movement toward tetrasaccharides was demonstrated in capillary cultures.
L. ruminis
utilized 3-
O
-β-cellotriosyl-
d
-glucose released by β-glucan hydrolysis due to bowel commensal
Coprococcus
sp., indicating that cross feeding of tetrasaccharide between bacteria could occur. Therefore, the RNA-seq screen and subsequent experiments had utility in revealing foraging attributes of gut commensal
Lactobacillus ruminis
.
Benzoyl Coenzyme A Pathway-Mediated Metabolism of
meta
-Hydroxy-Aromatic Acids in Rhodopseudomonas palustris
Authors: Gall Daniel L. , Ralph John , Donohue Timothy J. , Noguera Daniel R. 
Published: July 2013

ABSTRACT

Photoheterotrophic metabolism of two
meta
-hydroxy-aromatic acids,
meta
-,
para
-dihydroxybenzoate (protocatechuate) and
meta
-hydroxybenzoate, was investigated in
Rhodopseudomonas palustris
. When protocatechuate was the sole organic carbon source, photoheterotrophic growth in
R. palustris
was slow relative to cells using compounds known to be metabolized by the benzoyl coenzyme A (benzoyl-CoA) pathway.
R. palustris
was unable to grow when
meta
-hydroxybenzoate was provided as a sole source of organic carbon under photoheterotrophic growth conditions. However, in cultures supplemented with known benzoyl-CoA pathway inducers (
para
-hydroxybenzoate, benzoate, or cyclohexanoate), protocatechuate and
meta
-hydroxybenzoate were taken up from the culture medium. Further, protocatechuate and
meta
-hydroxybenzoate were each removed from cultures containing both
meta
-hydroxy-aromatic acids at equimolar concentrations in the absence of other organic compounds. Analysis of changes in culture optical density and in the concentration of soluble organic compounds indicated that the loss of these
meta
-hydroxy-aromatic acids was accompanied by biomass production. Additional experiments with defined mutants demonstrated that enzymes known to participate in the dehydroxylation of
para
-hydroxybenzoyl-CoA (HbaBCD) and reductive dearomatization of benzoyl-CoA (BadDEFG) were required for metabolism of protocatechuate and
meta
-hydroxybenzoate. These findings indicate that, under photoheterotrophic growth conditions,
R. palustris
can degrade
meta
-hydroxy-aromatic acids via the benzoyl-CoA pathway, apparently due to the promiscuity of the enzymes involved.
Persistence of DNA in a Cured Patient and Positive Culture in Cases with Low Antibody Levels Bring into Question Diagnosis of Q Fever Endocarditis
Authors: Edouard Sophie , Million Matthieu , Lepidi Hubert , Rolain Jean-Marc , Fournier Pierre-Edouard , La Scola Bernard , Grisoli Dominique , Raoult Didier 
Published: July 2013

ABSTRACT

We evaluated the performance of tools for diagnosing Q fever cardiovascular infection. We retrospectively analyzed 162 cardiovascular samples from 125 patients who were tested serologically by immunofluorescence, quantitative PCR (qPCR), 16S rRNA gene amplification, culture, and immunohistochemistry, and we assessed the viability of
Coxiella burnetii
by measuring the transcription of the 16S rRNA gene. The qPCR technique was significantly more sensitive than 16S rRNA gene amplification (
P
< 0.0001), cell culture (
P
= 0.0002), and immunohistochemistry (
P
< 0.0001). The sensitivity of these techniques was reduced when applied to patients who had been previously treated. The severity of infection appears to be correlated with phase I IgG levels. We report for the first time 4 cases of endocarditis with positive qPCR and/or culture assay result from patients with a low phase I IgG (IgG I) titer (<800), and we have identified the longest (16 years) persistence of DNA described in a heart valve from a patient cured after being previously treated for endocarditis. The active transcription of the 16S rRNA gene was found in 19/59 tested samples, with a positive predictive value of 100% for a positive culture. In conclusion, the diagnosis of Q fever cardiovascular infection should not be excluded in patients with low titers of phase I IgG when they present with valvulopathy. We recommend testing cardiovascular samples using 3 or 4 different biopsy sections by qPCR evaluation for patients with IgG I titers of ≥200.
Diagnostic Implications of Inconsistent Results Obtained with the Xpert MTB/Rif Assay in Detection of Mycobacterium tuberculosis Isolates with an
rpoB
Mutation Associated with Low-Level Rifampin Resistance
Authors: Somoskovi Akos , Deggim Vanessa , Ciardo Diana , Bloemberg Guido V. 
Published: July 2013

ABSTRACT

Xpert-MTB/Rif is one of the most frequently used molecular screening tests for multidrug-resistant tuberculosis worldwide. We report false-negative assay results in the presence of
rpoB
Leu533Pro, which is associated with low-level phenotypic rifampin resistance. Accurate and timely confirmation of rifampin susceptibility results obtained with Xpert-MTB/Rif is imperative.
Interlaboratory Comparison of Intact-Cell Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Results for Identification and Differentiation of Brucella spp
Authors: Karger Axel , Melzer Falk , Timke Markus , Bettin Barbara , Kostrzewa Markus , Nöckler Karsten , Hohmann Angelika , Tomaso Herbert , Neubauer Heinrich , Al Dahouk Sascha 
Published: July 2013

ABSTRACT

Classical microbiological diagnosis of human brucellosis is time-consuming, hazardous, and subject to variable interpretation. Intact-cell matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was evaluated for the routine identification of
Brucella
spp. Analysis of mass peak patterns allowed accurate identification to the genus level. However, statistical models based on peak intensities were needed for definite species differentiation. Interlaboratory comparison confirmed the reproducibility of the results.
Implementation of a rapid HIV testing programme favourably impacts provider opinions on emergency department HIV testing
Authors: Schechter-Perkins Elissa M , Rubin-Smith Julia E , Mitchell Patricia M 
Published: July 2013

ObjectiveTo assess staff knowledge of Centers for Disease Control (CDC) guidelines, attitudes and barriers towards emergency department (ED) HIV testing before and after implementing an ED rapid HIV testing programme (EDRHTP).MethodsWe conducted a cross-sectional pre/post survey at an urban academic medical centre. In March 2009, ED registered nurses (RNs) and doctors (MDs) participated in an anonymous survey. An EDRHTP was established in September 2009, and in March 2011, the survey was redistributed to ED staff. Differences before and after programme implementation were assessed using χ2statistics or Fisher's exact test.ResultsRespondents reported greater familiarity with CDC guidelines after programme implementation (44% vs 59%, p=0.04) and more believed that HIV testing should be offered to all ED patients (44% vs 79%, p<0.0001). Prior to programme implementation, RNs and MDs differed in attitudes towards ED HIV testing across most questions, and differences disappeared post programme.ConclusionsOverall support for ED HIV testing increased after establishment of a rapid testing programme.
Ergonomic assessment of enhanced protection under body armour combat shirt neck collars
Authors: Breeze John , Granger C J , Pearkes T D , Clasper J C 
Published: July 2013

IntroductionCombat neck injury due to explosively propelled fragments is a significant cause of mortality and long-term morbidity in UK soldiers deployed on current operations. Reinforcing the collar of the existing under body armour combat shirt (UBACS) has been suggested as a potential method for reducing the incidence of combat neck injury.Method20 soldiers serving in Afghanistan objectively compared three designs of enhanced protection UBACS (EP-UBACS) using 10 representative military tasks against a baseline of a standard UBACS. Each EP-UBACS design was trialled using three constituent materials: two layers of para-aramid felt, one layer of ultra high molecule weight polyethylene (UHMWPE) felt or two layers of a silk fabric. Subjective assessment of these nine configurations in terms of comfort, heat dissipation and overall acceptability were compared with the standard UBACS using a χ2test.ResultsAll military tasks could be performed with all nine configurations of EP-UBACS. Although silk was the most comfortable material, it was not functionally practical in any of the three designs. Crossover collars incorporating UHMWPE or para-aramid were the only two of the nine configurations to demonstrate similar user acceptability to a standard UBACS.ConclusionsThe EP-UBACS has the potential to provide neck protection without reducing performance incorporating materials analogous to either of the felts assessed in this study. The collar should provide stand-off from the skin to improve heat dissipation and comfort, which can be maximised by changing the current UBACS collar shape to one that crosses over at the front. Should a zip be desired, it should be moved to one side of the midline to reduce rubbing on the chin and be covered with ballistic protective material. Additional semi-circles of silk beneath the collar at the front and back would improve protection without affecting comfort.
Republished: Interleukin 13 and its role in gut defence and inflammation
Authors: Mannon Peter , Reinisch Walter 
Published: July 2013

Abstract
Interleukin 13 (IL-13) is a cytokine of increasing interest to gastroenterologists because of its developing role in ulcerative colitis, eosinophilic oesophagitis (EO) and fibrosis. Recent data show that IL-13 may play an important role in a novel innate immune response since it can be released by signals from an injured or inflamed epithelium, of particular relevance to the gut. Animal models of IL-13-driven inflammation (from asthma to colitis and EO) are being translated to human disease and providing insight into potential strategies for new therapies. In fact, multiple clinical trials using anti-IL-13 drugs are underway in asthma and are being extended to gastrointestinal diseases. This review presents the current knowledge on IL-13 production and function in the gut, including the cells and receptor signalling pathways involved in mediating IL-13 effects, the proposed mechanisms of IL-13 induced gut disease and the many drugs currently being tested that target IL-13 related pathways.
Lymphogranuloma venereum diagnoses among men who have sex with men in the UK: interpreting a cross-sectional study using an epidemic phase-specific framework
Authors: Hughes Gwenda , Alexander Sarah , Simms Ian , Conti Stefano , Ward Helen , Powers Cassandra , Ison Catherine ,   on behalf of the LGV Incident Group
Published: July 2013

ObjectivesTo investigate the drivers behind the epidemic expansion of lymphogranuloma venereum (LGV) cases in late 2009 to help inform infection control.MethodsAn epidemic curve of all LGV diagnoses between 2003 and mid-2012 was plotted and divided into the initial detection period, and endemic, growth and hyperendemic phases. Detailed clinical and behavioural data were collected and logistic regression was used to compare the characteristics of diagnoses made during the growth and endemic phases.ResultsBetween April 2003 and June 2012, 2138 cases of LGV were diagnosed. Enhanced surveillance data were available for 1370 of whom 1353 were men who have sex with men (MSM). 98% of MSM presented with proctitis, 82% were HIV positive, 20% were hepatitis C virus (HCV) antibody positive, and 67% lived in London. Growth phase cases (n=488) were more likely to report meeting sexual contacts at sex parties (11% vs 6%, p=0.014), unprotected receptive or insertive oral intercourse (93% vs 86%, p=0.001; 92% vs 85%, p=0.001) and sharing sex toys (8% vs 4%; p=0.011), and to be diagnosed HIV positive (86% vs 80%; p=0.014), than endemic phase cases (n=423). Unprotected receptive anal intercourse was equally likely to be reported in both phases (71% vs 73%). After adjustment, cases in the growth phase were more likely to meet new contacts at sex parties (p=0.031) and be HIV positive (p=0.045).ConclusionsRapid epidemic growth coincided with an intensification of unprotected sexual activity among a core population of HIV-positive MSM. Efforts to develop innovative interventions for this hard-to-reach population are needed.