bluuebunny/crossref_metadata_2025 huggingface dataset:
The endogenous modeling of the effect of direct‐to‐consumer advertising in prescription drugs
Authors: Kalyanaram G.K.
Published: June 2009

Purpose

The purpose of this paper is to study two major research objectives. The first objective is to investigate the effect of direct‐to‐consumer advertising (DTCA) on market share in the pharmaceutical drugs industry by modeling advertising decision of the firm as an endogenous decision. The second objective is to examine and determine whether there is any empirical support for the argument advanced by medical insurers and providers that DTCA advertising encourages brand switching.

Design/methodology/approach

Data on sales, price, DTCA, direct‐to‐physician advertising (DTPA), and average cost of consumption per usage for three prescription (Rx) drugs categories was obtained for the period, January 1998 to December 1999. A simultaneous model of market share and DTCA is proposed. Market share is modeled as a function of DTCA, price, the intensity of competition as represented by the number of competitive brands, and DTPA. DTCA is modeled as a function of its lagged market share (with the optimal number of lags to be determined empirically), and the average cost per consumption usage.

Findings

This paper finds that there is a positive and significant effect of DTCA on market share when advertising decision is modeled as an endogenous decision. The empirical results suggest brand switching by consumers. There is, thus, some evidentiary support for the argument made by the insurance providers.

Originality/value

This paper is unique for two reasons. First, the paper estimates the effects of DTCA in a simultaneous model accounting for endogenous decision by the firm. Therefore, the estimates are unbiased and robust. Second, the paper investigates the important public policy question of the social welfare of DTCA.
Nutritious food intake: a new competitive advantage for organizations?
Authors: Houghton Jeffery , Neck Christopher , Cooper Kenneth
Published: June 2009

Purpose

The purpose of this paper is to suggest that nutritious food intake is a somewhat overlooked yet essential aspect of corporate wellness that has the potential to help provide organizations with a sustainable competitive advantage.

Design/methodology/approach

The paper first discusses the resource‐based view, identifying ways in which nutritious food intake across an organization may serve to create rare and inimitable organizational resources leading to a competitive advantage. It then presents a basic overview of the fundamentals of nutritious food intake. It proceeds to review the transtheoretical stages of change model in the context of tailored nutrition interventions in organizations, providing a detailed overview of key individual behavior focused and environmental focused change strategies along with a discussion of types of technical delivery systems.

Findings

The paper suggests that an organization may be able to use a tailored stage‐based nutrition intervention as part of a comprehensive wellness program in order to help create a sustainable competitive advantage based on the nutritious food intake of its members.

Research limitations/implications

Future researchers should continue to examine the effectiveness of stage‐based computer tailored nutrition interventions and their delivery systems, particularly in the context of comprehensive corporate wellness plans and the extent to which this serves to create a competitive advantage through lower direct healthcare costs and higher worker productivity.

Practical implications

Organizational leaders should carefully consider the strategies and methodologies presented in this paper when designing and implementing nutrition interventions as part of a broad corporate wellness program.

Originality/value

This paper makes a valuable contribution to the organizational literature by recognizing the potential for the application of the transtheoretical stages of change model from the field of nutrition education within the context of the resource‐based view of organizations.
A meta analysis of ISO 9001:2000 research – findings and future research proposals
Authors: Psomas Evangelos L. , Fotopoulos Christos V.
Published: June 2009

Purpose

The purpose of this paper is to review and classify the main findings of the studies undertaken on ISO 9001:2000 certified companies and to present future research proposals.

Design/methodology/approach

A comprehensive literature review is carried out focusing on research papers published in academic literature. Both, the most recently published papers as well as those concerned only with the 2000 version of the ISO 9001 standard are chosen. The findings from the research papers are classified according to the issues examined.

Findings

The many studies undertaken regarding the ISO 9001:2000 implementation show that although there are signs that the initial results are not so positive, the general conclusion is that the standard has positive impact on the company's operational as well as business performance and on the company's effort to move towards total quality management. However, many research proposals have been expressed in order to fully determine the long‐term results as well as to specify a valid model containing the fundamental quality management practices which can effectively drive a company to business excellence.

Practical implications

Having in mind that the ISO 9001:2000 is getting to its end and a new revised standard is being given birth (ISO 9001:2008); the paper reveals that the research agenda is still full of topics that have to be considered in order to fully understand the standard's implications. Hence, given the findings from the researches carried out until now and the modifications made to the requirements of the new standard, this paper gives directions for effective transition to the revised standard as well as for future research studies.

Originality/value

Reviewing the literature, it is observed that many research papers regarding the ISO 9001:2000 standard have already been published. This paper classifies the research findings and points out future research proposals in order to fully explore the quality management discipline.
Exploring the epistemological origins of Shewhart's and Deming's theory of quality
Authors: Mauléon Christina , Bergman Bo
Published: June 2009

Purpose

The purpose of this paper is to explore the epistemological origin of Shewhart's and Deming's ideas in their development of a theory of quality.

Design/methodology/approach

The approach takes the form of a literature review.

Findings

Walter. A. Shewhart's and W. Edwards Deming's ideas concerning a theory of quality originated not solely from insights about variation within statistics but also from the field of philosophy, particularly epistemology. Shewhart and Deming, both seen as quality pioneers, were strongly influenced by the conceptualistic pragmatist Clarence Irving Lewis and his theory of knowledge. This is, and has often been, a neglected connection; however, in today's competitive business environment knowledge and competence have become crucial success factors. Thus, the epistemology‐related origin of their theory of quality has become increasingly interesting and important to explore. First, a summary version of Clarence Irving Lewis' theory of knowledge will be presented here as expressed in his work Mind and the World Order: Outline of a Theory of Knowledge (1929). Second, examples of some important connections between Lewis, and chosen parts of Shewhart's and Deming's theory of quality will be given, for example the plan‐do‐study‐act cycle, operational definitions and profound knowledge. It will also be indicated how the social element in knowledge is emphasised in the works of Lewis, Deming, and Shewhart.

Originality/value

By exploring the epistemological background of Deming's and Shewhart's ideas of a theory of quality, it might be able to better comprehend the profound ideas they left behind and improve the understanding and use of their theory of quality today.
A review of twenty years of SERVQUAL research
Authors: Ladhari Riadh
Published: June 2009

Purpose

This paper reviews 20 years (1988‐2008) of research on the SERVQUAL scale for measuring service quality.

Design/methodology/approach

A range of studies that have applied the SERVQUAL scale in this 20‐year period are examined in a non‐exhaustive review of the literature. These studies are selected from well‐known databases – such as “ABI/Inform”, “ScienceDirect”, and “EBSCOhost”.

Findings

The paper identifies and summarizes numerous theoretical and empirical criticisms of the SERVQUAL scale. Despite these criticisms, the paper concludes that SERVQUAL remains a useful instrument for service‐quality research.

Originality/value

The paper provides a useful source of information on SERVQUAL and its applications. In particular, the paper summarizes a selection of 30 applications of SERVQUAL.
Rankings of academic journals in accounting, finance, and information system
Authors: Wu Ji , Hao Qian , Yao Michelle Y.M.
Published: June 2009

Purpose

The purpose of this paper is report the importance of research publications for the tenure promotion and for faculty in accounting, finance, and information system (IS) areas, developing valid criteria for the assessment of quality in related journals is necessary.

Design/methodology/approach

Existing rankings are usually based on a survey among faculty members, while ignoring the chairs' critical role in tenure evaluation. This paper uses department chairs' responses to a survey asking to assess relative journal quality, and hence provides quantitative standards to measure research productivity. The rankings are primarily obtained by the familiarity‐rank position index method. Different sets of rankings for the decision‐makers in universities, with various requirements for research are provide.

Findings

It is found that the rankings in accounting and finance areas are consistent with the prior research, but the rankings in the IS have changed significantly. This difference to the rapid growth in the field of IS is attributed. The robustness check also corroborates the ranking lists.

Originality/value

In addition, this paper reports not only a comprehensive ranking list including most journals in accounting, finance, and IS areas, but also separate rankings in each field.
The pervasive nature of IT controls
Authors: Canada Joseph , Sutton Steve G. , Randel Kuhn J.
Published: June 2009

Purpose

The complexity of computerized information systems increases the complexity of the external auditor's assessment of the reliability of a client's internal control systems. The purpose of this paper is to investigate the impact of weaknesses in IT related internal controls on the cost of a SOX 404 audit of internal controls over financial reporting.

Design/methodology/approach

The paper considers the impact on audit fees through three dimensions: percentage increase in audit fees; amount of change in audit fees per outstanding common share; and actual dollar amount of audit fees. Examination of first year reports by accelerated filers yields 131 companies with material IT‐control weaknesses. These 131 companies are matched with a similar set of companies with no reported material weaknesses, and for a subset of 54 from the 131 companies in which a good match could be identified, a set of companies having only material non‐IT‐based control weaknesses are compared.

Findings

As expected, substantial fee differentials were identified for companies reporting material IT‐based control weaknesses as compared to both companies without any material weaknesses and those companies with only non‐IT related material weaknesses.

Originality/value

Preliminary evidence in regard to the costs of SOX 404 compliance for stockholders is provided. The cost of SOX 404 compliance has often been cited in criticisms of SOX, yet the focus of SOX is not on corporate wealth, but rather on enhancing corporate governance to protect the interest of stockholders. The cost of SOX compliance across the number of reported outstanding common shares for the companies studied is factored. It is found that the increased cost of audit fees on a per share basis is higher for companies reporting IT material weaknesses.
Feeding signals to the hungry mind
Authors: Balthasar Nina
Published: June 2009

Obesity, due to its associated co‐morbidities, including type 2 diabetes and cardiovascular disease, is at the forefront of today's health care concerns. Our need for novel, multifaceted approaches to tackle the global increase of waistlines is urgent, and understanding the physiological processes underlying our vulnerability to weight gain is an important one of them. Evidence for considerable heritability of body weight indicates genetic influences in the susceptibility to our obesogenic environment. Here, we will focus on neurons in brain structures such as the hypothalamus, which sense the body's metabolic state and, through an intricate cascade of events, elicit an appropriate response. We will explore the use of genetically modified mouse models in the investigation of physiological functions of genes and pathways in neuronal regulation of metabolic balance. Use of these techniques allows us to make manipulations at the molecular level (e.g. in the neuronal metabolic sensing mechanism) and combine this with systems‐level physiological analysis (e.g. body weight). Recent technological advances also enable the investigation of the contributions of genes to the co‐morbidities of obesity, such as obesity‐induced hypertension. Reviewing examples of improvements as well as large gaps in our knowledge, this lecture aims to incite interest in whole body physiological research.
Role of thyroid hormones in the developmental control of tissue glycogen in fetal sheep near term
Authors: Forhead Alison J. , Cutts Samantha , Matthews Phillippa A. , Fowden Abigail L.
Published: June 2009

Developmental and glucocorticoid‐induced changes in tissue glycogen content occur in the fetus near term coincident with an increase in plasma triiodothyronine (T3), although the role of thyroid hormones in mediating these changes is unknown. This study investigated glycogen content in the liver, heart and skeletal muscle of sheep fetuses after experimental manipulation of thyroid hormone concentrationin uteroby T3infusion and fetal thyroidectomy (TX). At 130 days of gestation (term 145 ± 2 days), hepatic glycogen was greater, and muscle glycogen was lower, in the TX fetuses than in the intact fetuses. However, between 130 and 144 days of gestation the normal increment in hepatic glycogen, and decrement in cardiac glycogen, seen in intact fetuses was abolished when the prepartum rise in T3, but not cortisol, was prevented by TX. At 144 days of gestation, hepatic glycogen was lower, and cardiac glycogen was higher, in the TX compared with intact fetuses. In intact fetuses at 130 days of gestation, 5 days of intravenous T3infusion (8–12 μg kg−1day−1) caused a small but significant increase in hepatic glycogen, although the concentration achieved was not as great as that observed in intact fetuses infused with cortisol (2–3 mg kg−1day−1) for 5 days. Infusion of T3reduced cardiac glycogen to the level observed in mature fetuses near term and immature fetuses infused with cortisol for 5 days. Glycogen content in fetal skeletal muscle increased between 100 and 115 days of gestation, but was unaffected by cortisol or T3infusion. Therefore, thyroid hormones are important in the developmental control of hepatic and cardiac glycogen content in the ovine fetus near term and may mediate, in part, the maturational effects of cortisol.
Functional Amyloids As Natural Storage of Peptide Hormones in Pituitary Secretory Granules
Authors: Maji Samir K. , Perrin Marilyn H. , Sawaya Michael R. , Jessberger Sebastian , Vadodaria Krishna , Rissman Robert A. , Singru Praful S. , Nilsson K. Peter R. , Simon Rozalyn , Schubert David , Eisenberg David , Rivier Jean , Sawchenko Paul , Vale Wylie , Riek Roland
Published: June 2009

Plethora of Secretory Amyloids

Protein aggregation and the formation of amyloids are associated with several dozen pathological conditions in humans, including Alzheimer's disease, Parkinson's disease, and type II diabetes. In addition, a few functional amyloid systems are known: the prions of fungi, the bacterial protein curli, the protein of chorion of the eggshell of silkworm, and the amyloid protein Pmel-17 involved in mammalian skin pigmentation. Now

Maji
et al.

(p.
328
, published online 18 June) propose that endocrine hormone peptides and proteins are stored in an amyloid-like state in secretory granules. Thus, the amyloid fold may represent a fundamental, ancient, and evolutionarily conserved protein structural motif that is capable of performing a wide variety of functions contributing to normal cell and tissue physiology.
Translocator Protein (18 kD) as Target for Anxiolytics Without Benzodiazepine-Like Side Effects
Authors: Rupprecht Rainer , Rammes Gerhard , Eser Daniela , Baghai Thomas C. , Schüle Cornelius , Nothdurfter Caroline , Troxler Thomas , Gentsch Conrad , Kalkman Hans O. , Chaperon Frederique , Uzunov Veska , McAllister Kevin H. , Bertaina-Anglade Valerie , La Rochelle Christophe Drieu , Tuerck Dietrich , Floesser Annette , Kiese Beate , Schumacher Michael , Landgraf Rainer , Holsboer Florian , Kucher Klaus
Published: June 2009

Keeping Calm

Benzodiazepines are the most prescribed anxiolytics and are used by a broad population. However, benzodiazepines can cause unwanted side effects, including sedation, development of tolerance, and withdrawal symptoms after long-term administration.Rupprechtet al.(p.490; published online 18 June) now find that a translocator protein (18-kD) ligand, XBD173, is a fast-acting anxiolytic agent, both in animals and humans, which lacks the unwanted side effects of benzodiazepines and provides a promising target for novel clinically effective anxiolytic drugs.
Variability of
Burkholderia pseudomallei
Strain Sensitivities to Chlorine Disinfection
Authors: O'Connell Heather A. , Rose Laura J. , Shams Alicia , Bradley Meranda , Arduino Matthew J. , Rice Eugene W.
Published: June 2009

Burkholderia pseudomallei
is a select agent and the causative agent of melioidosis. Variations in previously reported chlorine and monochloramine concentration time (Ct) values for disinfection of this organism make decisions regarding the appropriate levels of chlorine in water treatment systems difficult. This study identified the variation in Ct values for 2-, 3-, and 4-log
10
reductions of eight environmental and clinical isolates of
B. pseudomallei
in phosphate-buffered water. The greatest calculated Ct values for a 4-log
10
inactivation were 7.8 mg·min/liter for free available chlorine (FAC) at pH 8 and 5°C and 550 mg·min/liter for monochloramine at pH 8 and 5°C. Ionic strength of test solutions, culture hold times in water, and cell washing were ruled out as sources of the differences in prior observations. Tolerance to FAC was correlated with the relative amount of extracellular material produced by each isolate. Solid-phase cytometry analysis using an esterase-cleaved fluorochrome assay detected a 2-log
10
-higher level of organisms based upon metabolic activity than did culture, which in some cases increased Ct values by fivefold. Despite strain-to-strain variations in Ct values of 17-fold for FAC and 2.5-fold for monochloramine, standard FAC disinfection practices utilized in the United States should disinfect planktonic populations of these
B. pseudomallei
strains by 4 orders of magnitude in less than 10 min at the tested temperatures and pH levels.
Comparative Genome-Wide Transcriptional Profiling of
Azorhizobium caulinodans
ORS571 Grown under Free-Living and Symbiotic Conditions
Authors: Tsukada Shuhei , Aono Toshihiro , Akiba Noriko , Lee Kyung-Bum , Liu Chi-Te , Toyazaki Hiroki , Oyaizu Hiroshi
Published: June 2009

The whole-genome sequence of the endosymbiotic bacterium
Azorhizobium caulinodans
ORS571, which forms nitrogen-fixing nodules on the stems and roots of
Sesbania rostrata
, was recently determined. The sizes of the genome and symbiosis island are 5.4 Mb and 86.7 kb, respectively, and these sizes are the smallest among the sequenced rhizobia. In the present study, a whole-genome microarray of
A. caulinodans
was constructed, and transcriptomic analyses were performed on free-living cells grown in rich and minimal media and in bacteroids isolated from stem nodules. Transcriptional profiling showed that the genes involved in sulfur uptake and metabolism, acetone metabolism, and the biosynthesis of exopolysaccharide were highly expressed in bacteroids compared to the expression levels in free-living cells. Some mutants having Tn
5
transposons within these genes with increased expression were obtained as nodule-deficient mutants in our previous study. A transcriptomic analysis was also performed on free-living cells grown in minimal medium supplemented with a flavonoid, naringenin, which is one of the most efficient inducers of
A. caulinodans nod
genes. Only 18 genes exhibited increased expression by the addition of naringenin, suggesting that the regulatory mechanism responding to the flavonoid could be simple in
A. caulinodans.
The combination of our genome-wide transcriptional profiling and our previous genome-wide mutagenesis study has revealed new aspects of nodule formation and maintenance.
Aerobic Biodegradation of
N
-Nitrosodimethylamine by the Propanotroph
Rhodococcus ruber
ENV425
Authors: Fournier Diane , Hawari Jalal , Halasz Annamaria , Streger Sheryl H. , McClay Kevin R. , Masuda Hisako , Hatzinger Paul B.
Published: June 2009

The propanotroph
Rhodococcus ruber
ENV425 was observed to rapidly biodegrade
N
-nitrosodimethylamine (NDMA) after growth on propane, tryptic soy broth, or glucose. The key degradation intermediates were methylamine, nitric oxide, nitrite, nitrate, and formate. Small quantities of formaldehyde and dimethylamine were also detected. A denitrosation reaction, initiated by hydrogen atom abstraction from one of the two methyl groups, is hypothesized to result in the formation of
n
-methylformaldimine and nitric oxide, the former of which decomposes in water to methylamine and formaldehyde and the latter of which is then oxidized further to nitrite and then nitrate. Although the strain mineralized more than 60% of the carbon in [
14
C]NDMA to
14
CO
2
, growth of strain ENV425 on NDMA as a sole carbon and energy source could not be confirmed. The bacterium was capable of utilizing NDMA, as well as the degradation intermediates methylamine and nitrate, as sources of nitrogen during growth on propane. In addition, ENV425 reduced environmentally relevant microgram/liter concentrations of NDMA to <2 ng/liter in batch cultures, suggesting that the bacterium may have applications for groundwater remediation.
Comparative Metagenomic Analysis of a Microbial Community Residing at a Depth of 4,000 Meters at Station ALOHA in the North Pacific Subtropical Gyre
Authors: Konstantinidis Konstantinos T. , Braff Jennifer , Karl David M. , DeLong Edward F.
Published: June 2009

The deep sea (water depth of >2,000 m) represents the largest biome on Earth. Yet relatively little is known about its microbial community's structure, function, and adaptation to the cold and deep biosphere. To provide further genomic insights into deep-sea planktonic microbes, we sequenced a total of ∼200 Mbp of a random whole-genome shotgun (WGS) library from a microbial community residing at a depth of 4,000 m at Station ALOHA in the Pacific Ocean and compared it to other available WGS sequence data from surface and deep waters. Our analyses indicated that the deep-sea lifestyle is likely facilitated by a collection of very subtle adaptations, as opposed to dramatic alterations of gene content or structure. These adaptations appear to include higher metabolic versatility and genomic plasticity to cope with the sparse and sporadic energy resources available, a preference for hydrophobic and smaller-volume amino acids in protein sequences, unique proteins not found in surface-dwelling species, and adaptations at the gene expression level. The deep-sea community is also characterized by a larger average genome size and a higher content of “selfish” genetic elements, such as transposases and prophages, whose propagation is apparently favored by more relaxed purifying (negative) selection in deeper waters.
Significant Enhanced Expression and Solubility of Human Proteins in
Escherichia coli
by Fusion with Protein S from
Myxococcus xanthus
Authors: Kobayashi Hiroshi , Yoshida Takeshi , Inouye Masayori
Published: June 2009

Protein S is a major spore coat protein of
Myxococcus xanthus
, consisting of two homologous domains, the N-terminal domain (NTD) and the C-terminal domain, both of which contain a Ca
2+
-binding site. Protein S tightly binds to myxospores in a Ca
2+
-dependent manner. Here, we constructed a novel expression vector, pCold-PST, encoding two tandem repeat NTDs (PrS
2
). By using this vector, a number of human proteins that were expressed at low levels or in insoluble forms by a pET vector were expressed not only at high levels but also in soluble forms. We also demonstrated that an
Escherichia coli
protein tagged with PrS
2
fully retained its function, indicating that it is folded independently from the tag. This technology not only allows simple, one-step protein purification using myxospores, but can also be used for the identification of proteins interacting with a protein of interest and will prove immensely useful for structural studies of proteins which are difficult to produce or are insoluble.
Evolution and Diversity of Facultative Symbionts from the Aphid Subfamily Lachninae
Authors: Burke Gaelen R. , Normark Benjamin B. , Favret Colin , Moran Nancy A.
Published: June 2009

Many aphids harbor a variety of endosymbiotic bacteria. The functions of these symbionts can range from an obligate nutritional role to a facultative role in protecting their hosts against environmental stresses. One such symbiont is “CandidatusSerratia symbiotica,” which is involved in defense against heat and potentially also in aphid nutrition. Lachnid aphids have been the focus of several recent studies investigating the transition of this symbiont from a facultative symbiont to an obligate symbiont. In a phylogenetic analysis ofSerratiasymbionts from 51 lachnid hosts, we found that diversity in symbiont morphology, distribution, and function is due to multiple independent origins of symbiosis from ancestors belonging toSerratiaand possibly also to evolution within distinct symbiont clades. Our results do not support cocladogenesis of “Ca. Serratia symbiotica” withCinarasubgenusCinaraspecies and weigh against an obligate nutritional role. Finally, we show that species belonging to the subfamily Lachninae have a high incidence of facultative symbiont infection.
Synthetic Ultrashort Cationic Lipopeptides Induce Systemic Plant Defense Responses against Bacterial and Fungal Pathogens
Authors: Brotman Yariv , Makovitzki Arik , Shai Yechiel , Chet Ilan , Viterbo Ada
Published: June 2009

A new family of synthetic, membrane-active, ultrashort lipopeptides composed of only four amino acids linked to fatty acids was tested for the ability to induce systemic resistance and defense responses in plants. We found that two peptides wherein the third residue is a
d
-enantiomer (italic), C
16
-KK
K
K and C
16
-KL
L
K, can induce medium alkalinization of tobacco suspension-cultured cells and expression of defense-related genes in cucumber and
Arabidopsis
seedlings. Moreover, these compounds can prime systemic induction of antimicrobial compounds in cucumber leaves similarly to the plant-beneficial fungus
Trichoderma asperellum
T203 and provide systemic protection against the phytopathogens
Botrytis cinerea
B05,
Pseudomonas syringae
pv.
lachrimans
, and
P. syringae
pv.
tomato
DC3000. Thus, short cationic lipopeptides are a new category of compounds with potentially high utility in the induction of systemic resistance in plants.
Alleviation of Proteolytic Sensitivity To Enhance Recombinant Lipase Production in
Escherichia coli
Authors: Narayanan Niju , Chou C. Perry
Published: June 2009

Two amino acids, Leu149 and Val223, were identified as proteolytically sensitive when
Pseudozyma antarctica
lipase (PalB) was heterologously expressed in
Escherichia coli
. The functional expression was enhanced using the double mutant for cultivation. However, the recombinant protein production was still limited by PalB misfolding, which was resolved by DsbA coexpression.
Evolution of
Lactococcus lactis
Phages within a Cheese Factory
Authors: Rousseau Geneviève M. , Moineau Sylvain
Published: June 2009

We have sequenced the double-stranded DNA genomes of six lactococcal phages (SL4, CB13, CB14, CB19, CB20, and GR7) from the 936 group that were isolated over a 9-year period from whey samples obtained from a Canadian cheese factory. These six phages infected the same two industrial
Lactococcus lactis
strains out of 30 tested. The CB14 and GR7 genomes were found to be 100% identical even though they were isolated 14 months apart, indicating that a phage can survive in a cheese plant for more than a year. The other four genomes were related but notably different. The length of the genomes varied from 28,144 to 32,182 bp, and they coded for 51 to 55 open reading frames. All five genomes possessed a 3′ overhang
cos
site that was 11 nucleotides long. Several structural proteins were also identified by nano-high-performance liquid chromatography-tandem mass spectrometry, confirming bioinformatic analyses. Comparative analyses suggested that the most recently isolated phages (CB19 and CB20) were derived, in part, from older phage isolates (CB13 and CB14/GR7). The organization of the five distinct genomes was similar to the previously sequenced lactococcal phage genomes of the 936 group, and from these sequences, a core genome was determined for lactococcal phages of the 936 group.
Inactivation of PadR, the Repressor of the Phenolic Acid Stress Response, by Molecular Interaction with Usp1, a Universal Stress Protein fromLactobacillus plantarum, inEscherichia coli
Authors: Gury Jérôme , Seraut Hélène , Tran Ngoc Phuong , Barthelmebs Lise , Weidmann Stéphanie , Gervais Patrick , Cavin Jean-François
Published: June 2009

The phenolic acid decarboxylase genepadAis involved in the phenolic acid stress response (PASR) in gram-positive bacteria. InLactobacillus plantarum, thepadRgene encodes the negative transcriptional regulator ofpadAand is cotranscribed with a downstream gene,usp1, which encodes a putative universal stress protein (USP), Usp1, of unknown function. Theusp1gene is overexpressed during the PASR. However, the role and the mechanism of action of the USPs are unknown in gram-positive bacteria. Therefore, to gain insights into the role of USPs in the PASR; (i) ausp1deletion mutant was constructed; (ii) the two genespadRandusp1were coexpressed withpadAunder its own promoter as a reporter gene inEscherichia coli; and (iii) molecular in vitro interactions between the PadR, Usp1, and thepadApromoter were studied. Although theusp1mutant strain retained phenolic acid-dependent PAD activity, it displayed a greater sensitivity to strong acidic conditions compared to that of the wild-type strain. PadR cannot be inactivated directly by phenolic acid inE. colirecombinant cultures but is inactivated by Usp1 when the two proteins are coexpressed inE. coli.The PadR inactivation observed in recombinantE. colicells was supported by electrophoretic mobility shift assays. Although Usp1 seems not to be absolutely required for the PASR, its capacity to inactivate PadR indicates that it could serve as an important mediator in acid stress response mechanisms through its capacity to interact with transcriptional regulators.
Plasmid-Based System for High-Level Gene Expression and Antisense Gene Knockdown in
Bartonella henselae
Authors: Gillaspie Devin , Perkins Izabella , Larsen Kellie , McCord Amy , Pangonis Scott , Sweger Debra , Seleem Mohamed N. , Sriranganathan Nammalwar , Anderson Burt E.
Published: June 2009

Six broad-host-range plasmid vectors were developed to study gene expression in
Bartonella henselae
. The vectors were used to express a β-galactosidase reporter gene in
B. henselae
and to generate antisense RNA for gene knockdown. When applied to
ompR
, a putative transcription response regulator of
B. henselae
, this antisense RNA gene knockdown strategy reduced bacterial invasion of human endothelial cells by over 60%.
Msb2 Signaling Mucin Controls Activation of Cek1 Mitogen-Activated Protein Kinase in
Candida albicans
Authors: Román Elvira , Cottier Fabien , Ernst Joachim F. , Pla Jesús
Published: June 2009

We have characterized the role that the Msb2 protein plays in the fungal pathogen
Candida albicans
by the use of mutants defective in the putative upstream components of the HOG pathway. Msb2, in cooperation with Sho1, controls the activation of the Cek1 mitogen-activated protein kinase under conditions that damage the cell wall, thus defining Msb2 as a signaling element of this pathway in the fungus.
msb2
mutants display altered sensitivity to Congo red, caspofungin, zymolyase, or tunicamycin, indicating that this protein is involved in cell wall biogenesis. Msb2 (as well as Sho1 and Hst7) is involved in the transmission of the signal toward Cek1 mediated by the Cdc42 GTPase, as revealed by the use of activated alleles (Cdc42
G12V
) of this protein.
msb2
mutants have a stronger defective invasion phenotype than
sho1
mutants when tested on certain solid media that use mannitol or sucrose as a carbon source or under hypoxia. Interestingly, Msb2 contributes to growth under conditions of high osmolarity when both branches of the HOG pathway are altered, as triple
ssk1 msb2 sho1
mutants (but not any single or double mutant) are osmosensitive. However, this phenomenon is independent of the presence of Hog1, as Hog1 phosphorylation, Hog1 translocation to the nucleus, and glycerol accumulation are not affected in this mutant following an osmotic shock. These results reveal essential functions in morphogenesis, invasion, cell wall biogenesis, and growth under conditions of high osmolarity for Msb2 in
C. albicans
and suggest the divergence and specialization of this signaling pathway in filamentous fungi.
Remodeling of Global Transcription Patterns of
Cryptococcus neoformans
Genes Mediated by the Stress-Activated HOG Signaling Pathways
Authors: Ko Young-Joon , Yu Yeong Man , Kim Gyu-Bum , Lee Gir-Won , Maeng Pil Jae , Kim Sangsoo , Floyd Anna , Heitman Joseph , Bahn Yong-Sun
Published: June 2009

The ability to sense and adapt to a hostile host environment is a crucial element for virulence of pathogenic fungi, including
Cryptococcus neoformans
. These cellular responses are evoked by diverse signaling cascades, including the stress-activated HOG pathway. Despite previous analysis of central components of the HOG pathway, its downstream signaling network is poorly characterized in
C. neoformans
. Here we performed comparative transcriptome analysis with HOG signaling mutants to explore stress-regulated genes and their correlation with the HOG pathway in
C. neoformans
. In this study, we not only provide important insights into remodeling patterns of global gene expression for counteracting external stresses but also elucidate novel characteristics of the HOG pathway in
C. neoformans
. First, inhibition of the HOG pathway increases expression of ergosterol biosynthesis genes and cellular ergosterol content, conferring a striking synergistic antifungal activity with amphotericin B and providing an excellent opportunity to develop a novel therapeutic method for treatment of cryptococcosis. Second, a number of cadmium-sensitive genes are differentially regulated by the HOG pathway, and their mutation causes resistance to cadmium. Finally, we have discovered novel stress defense and HOG-dependent genes, which encode a sodium/potassium efflux pump, protein kinase, multidrug transporter system, and elements of the ubiquitin-dependent system.
Cell Envelope Perturbation Induces Oxidative Stress and Changes in Iron Homeostasis inVibrio cholerae
Authors: Sikora Aleksandra E. , Beyhan Sinem , Bagdasarian Michael , Yildiz Fitnat H. , Sandkvist Maria
Published: June 2009

TheVibrio choleraetype II secretion (T2S) machinery is a multiprotein complex that spans the cell envelope. When the T2S system is inactivated, cholera toxin and other exoproteins accumulate in the periplasmic compartment. Additionally, loss of secretion via the T2S system leads to a reduced growth rate, compromised outer membrane integrity, and induction of the extracytoplasmic stress factor RpoE (A. E. Sikora, S. R. Lybarger, and M. Sandkvist, J. Bacteriol.189:8484-8495, 2007). In this study, gene expression profiling reveals that inactivation of the T2S system alters the expression of genes encoding cell envelope components and proteins involved in central metabolism, chemotaxis, motility, oxidative stress, and iron storage and acquisition. Consistent with the gene expression data, molecular and biochemical analyses indicate that the T2S mutants suffer from internal oxidative stress and increased levels of intracellular ferrous iron. By using atolAmutant ofV. choleraethat shares a similar compromised membrane phenotype but maintains a functional T2S machinery, we show that the formation of radical oxygen species, induction of oxidative stress, and changes in iron physiology are likely general responses to cell envelope damage and are not unique to T2S mutants. Finally, we demonstrate that disruption of theV. choleraecell envelope by chemical treatment with polymyxin B similarly results in induction of the RpoE-mediated stress response, increased sensitivity to oxidants, and a change in iron metabolism. We propose that many types of extracytoplasmic stresses, caused either by genetic alterations of outer membrane constituents or by chemical or physical damage to the cell envelope, induce common signaling pathways that ultimately lead to internal oxidative stress and misregulation of iron homeostasis.
SlyA, a MarR Family Transcriptional Regulator, Is Essential for Virulence inDickeya dadantii3937
Authors: Haque M. Manjurul , Kabir M. Shahinur , Aini Luqman Qurata , Hirata Hisae , Tsuyumu Shinji
Published: June 2009

SlyA, a MarR family transcriptional regulator, controls an assortment of biological functions in several animal-pathogenic bacteria. In order to elucidate the functions of SlyA in the phytopathogenDickeya dadantii(formerlyErwinia chrysanthemi) 3937, aslyAgene deletion mutant (denoted ΔslyA) was constructed. The mutant exhibited increased sensitivity to sodium hypochlorite, the cationic antimicrobial peptide polymyxin B, and oxidative stress. The mutant showed reduced production of pectate lyase and exopolysaccharide and an inability to form a pellicle. The mutant lacking a functionalslyAgene showed a significantly reduced ability to cause maceration of potato tubers. Accordingly, the mutant exhibited significantly reduced bacterial growth and failed to hyperinduce pectate lyase production in planta. Introduction of a plasmid containingslyAinto the ΔslyAmutant caused all of these phenotypes to recover to wild-type levels. These results suggest that SlyA plays an important role in virulence to plants by positively regulating the expression of multiple pathogenicity-related traits ofD. dadantii3937.
Protein Domains and Residues Involved in the CheZ/CheA
S
Interaction
Authors: Cantwell Brian J. , Manson Michael D.
Published: June 2009

CheZ localizes to chemoreceptor patches by binding CheA-short (CheA
S
). Residues 70 to 134 of CheZ, constituting the apical loops and part of the dimerization domain, suffice for localization. Replacements of Tyr-118, Ile-119, Leu-123, Arg-124, and Leu-126 of CheA interfere with localization. These residues are exposed in the ′P1 domain of CheA
S
.
Kinematics of Intracellular Chlamydiae Provide Evidence for Contact-Dependent Development
Authors: Wilson David P. , Whittum-Hudson Judith A. , Timms Peter , Bavoil Patrik M.
Published: June 2009

A crucial process of chlamydial development involves differentiation of the replicative reticulate body (RB) into the infectious elementary body (EB). We present experimental evidence to provide support for a contact-dependent hypothesis for explaining the trigger involved in differentiation. We recorded live-imaging of
Chlamydia trachomatis
-infected McCoy cells at key times during development and tracked the temporospatial trajectories of individual chlamydial particles. We found that movement of the particles is related to development. Early to mid-developmental stages involved slight wobbling of RBs. The average speed of particles increased sharply at 24 h postinfection (after the estimated onset of RB to EB differentiation). We also investigated a penicillin-supplemented culture containing EBs, RBs, and aberrantly enlarged, stressed chlamydiae. Near-immobile enlarged particles are consistent with their continued tethering to the chlamydial inclusion membrane (CIM). We found a significantly negative, nonlinear association between speed and size/type of particles, providing further support for the hypothesis that particles become untethered near the onset of RB to EB differentiation. This study establishes the relationship between the motion properties of the chlamydiae and developmental stages, whereby wobbling RBs gradually lose contact with the CIM, and RB detachment from the CIM is coincidental with the onset of late differentiation.
Genetic Analysis of Activation of the
Vibrio cholerae
Cpx Pathway
Authors: Slamti Leyla , Waldor Matthew K.
Published: June 2009

The Cpx two-component system is thought to mediate envelope stress responses in many gram-negative bacteria and has been implicated in the pathogenicity of several enteric pathogens. While cues that activate the
Escherichia coli
Cpx system have been identified, the nature of the molecular signals that stimulate this pathway is not well understood. Here, we investigated stimuli that trigger this system in
Vibrio cholerae
, a facultative pathogen that adapts to various niches during its life cycle. In contrast to
E. coli
, there was no basal activity of the
V. cholerae
Cpx pathway under standard laboratory conditions. Furthermore, several known stimuli of the
E. coli
pathway did not induce expression of this system in
V. cholerae
. There were no defects in intestinal growth in
V
.
cholerae cpx
mutants, arguing against the idea that this pathway promotes
V
.
cholerae
adaptation to conditions in the mammalian host. We discovered that chloride ions activate the
V. cholerae
Cpx pathway, raising the possibility that this signal transduction system provides a means for
V. cholerae
to sense and respond to alterations in salinity. We used a genetic approach to screen for mutants in which the Cpx pathway is activated. We found that mutations in genes whose products are required for periplasmic disulfide bond isomerization result in activation of the Cpx pathway, suggesting that periplasmic accumulation of proteins with aberrant disulfide bonds triggers the
V. cholerae
Cpx pathway.
igr
Genes and
Mycobacterium tuberculosis
Cholesterol Metabolism
Authors: Chang Jennifer C. , Miner Maurine D. , Pandey Amit K. , Gill Wendy P. , Harik Nada S. , Sassetti Christopher M. , Sherman David R.
Published: June 2009

Recently, cholesterol was identified as a physiologically important nutrient for
Mycobacterium tuberculosis
survival in chronically infected mice. However, it remained unclear precisely when cholesterol is available to the bacterium and what additional bacterial functions are required for its metabolism. Here, we show that the
igr
locus, which we previously found to be essential for intracellular growth and virulence of
M
.
tuberculosis
, is required for cholesterol metabolism. While
igr
-deficient strains grow identically to the wild type in the presence of short- and long-chain fatty acids, the growth of these bacteria is completely inhibited in the presence of cholesterol. Interestingly, this mutant is still able to respire under cholesterol-dependent growth inhibition, suggesting that the bacteria can metabolize other carbon sources during cholesterol toxicity. Consistent with this hypothesis, we found that the growth-inhibitory effect of cholesterol in vitro depends on cholesterol import, as mutation of the
mce4
sterol uptake system partially suppresses this effect. In addition, the Δ
igr
mutant growth defect during the early phase of disease is completely suppressed by mutating
mce4
, implicating cholesterol intoxication as the primary mechanism of attenuation. We conclude that
M
.
tuberculosis
metabolizes cholesterol throughout infection.
Respiration of
Escherichia coli
Can Be Fully Uncoupled via the Nonelectrogenic Terminal Cytochrome
bd
-II Oxidase
Authors: Bekker M. , de Vries S. , Ter Beek A. , Hellingwerf K. J. , de Mattos M. J. Teixeira
Published: June 2009

The respiratory chain of
Escherichia coli
is usually considered a device to conserve energy via the generation of a proton motive force, which subsequently may drive ATP synthesis by the ATP synthetase. It is known that in this system a fixed amount of ATP per oxygen molecule reduced (P/O ratio) is not synthesized due to alternative NADH dehydrogenases and terminal oxidases with different proton pumping stoichiometries. Here we show that P/O ratios can vary much more than previously thought. First, we show that in wild-type
E. coli
cytochrome
bo
, cytochrome
bd
-I, and cytochrome
bd-
II are the major terminal oxidases; deletion of all of the genes encoding these enzymes results in a fermentative phenotype in the presence of oxygen. Second, we provide evidence that the electron flux through cytochrome
bd-
II oxidase is significant but does not contribute to the generation of a proton motive force. The kinetics support the view that this system is as an energy-independent system gives the cell metabolic flexibility by uncoupling catabolism from ATP synthesis under non-steady-state conditions. The nonelectrogenic nature of cytochrome
bd-
II oxidase implies that the respiratory chain can function in a fully uncoupled mode such that ATP synthesis occurs solely by substrate level phosphorylation. As a consequence, the yield with a carbon and energy source can vary five- to sevenfold depending on the electron flux distribution in the respiratory chain. A full understanding and control of this distribution open new avenues for optimization of biotechnological processes.
Proteomic and Genomic Characterization of Highly Infectious
Clostridium difficile
630 Spores
Authors: Lawley Trevor D. , Croucher Nicholas J. , Yu Lu , Clare Simon , Sebaihia Mohammed , Goulding David , Pickard Derek J. , Parkhill Julian , Choudhary Jyoti , Dougan Gordon
Published: June 2009

Clostridium difficile
, a major cause of antibiotic-associated diarrhea, produces highly resistant spores that contaminate hospital environments and facilitate efficient disease transmission. We purified
C. difficile
spores using a novel method and show that they exhibit significant resistance to harsh physical or chemical treatments and are also highly infectious, with <7 environmental spores per cm
2
reproducibly establishing a persistent infection in exposed mice. Mass spectrometric analysis identified ∼336 spore-associated polypeptides, with a significant proportion linked to translation, sporulation/germination, and protein stabilization/degradation. In addition, proteins from several distinct metabolic pathways associated with energy production were identified. Comparison of the
C. difficile
spore proteome to those of other clostridial species defined 88 proteins as the clostridial spore “core” and 29 proteins as
C. difficile
spore specific, including proteins that could contribute to spore-host interactions. Thus, our results provide the first molecular definition of
C. difficile
spores, opening up new opportunities for the development of diagnostic and therapeutic approaches.