bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of Antibiotic Resistance Genes in Source and Drinking Water Samples from a First Nations Community in Canada
Authors: Fernando Dinesh M. , Tun Hein Min , Poole Jenna , Patidar Rakesh , Li Ru , Mi Ruidong , Amarawansha Geethani E. A. , Fernando W. G. Dilantha , Khafipour Ehsan , Farenhorst Annemieke , Kumar Ayush 
Published: May 2016

ABSTRACT

Access to safe drinking water is now recognized as a human right by the United Nations. In developed countries like Canada, access to clean water is generally not a matter of concern. However, one in every five First Nations reserves is under a drinking water advisory, often due to unacceptable microbiological quality. In this study, we analyzed source and potable water from a First Nations community for the presence of coliform bacteria as well as various antibiotic resistance genes. Samples, including those from drinking water sources, were found to be positive for various antibiotic resistance genes, namely,
ampC
,
tet
(A),
mecA
, β-lactamase genes (SHV-type, TEM-type, CTX-M-type, OXA-1, and CMY-2-type), and carbapenemase genes (KPC, IMP, VIM, NDM, GES, and OXA-48 genes). Not surprisingly, substantial numbers of total coliforms, including
Escherichia coli
, were recovered from these samples, and this result was also confirmed using Illumina sequencing of the 16S rRNA gene. These findings deserve further attention, as the presence of coliforms and antibiotic resistance genes potentially puts the health of the community members at risk.

IMPORTANCE
In this study, we highlight the poor microbiological quality of drinking water in a First Nations community in Canada. We examined the coliform load as well as the presence of antibiotic resistance genes in these samples. This study examined the presence of antibiotic-resistant genes in drinking water samples from a First Nations Community in Canada. We believe that our findings are of considerable significance, since the issue of poor water quality in First Nations communities in Canada is often ignored, and our findings will help shed some light on this important issue.
Anaplasma marginale Actively Modulates Vacuolar Maturation during Intracellular Infection of Its Tick Vector, Dermacentor andersoni
Authors: Magunda Forgivemore , Thompson Chelsea Wright , Schneider David A. , Noh Susan M. 
Published: May 2016

ABSTRACTTick-borne transmission of bacterial pathogens in the orderRickettsialesis responsible for diverse infectious diseases, many of them severe, in humans and animals. Transmission dynamics differ among these pathogens and are reflected in the pathogen-vector interaction.Anaplasma marginalehas been shown to establish and maintain infectivity withinDermacentorspp. for weeks to months while escaping the complex network of vacuolar peptidases that are responsible for digestion of the tick blood meal. How this prolonged maintenance of infectivity in a potentially hostile environment is achieved has been unknown. Using the natural vectorDermacentor andersoni, we demonstrated thatA. marginale-infected tick vacuoles (AmVs) concurrently recruit markers of the early endosome (Rab5), recycling endosome (Rab4 and Rab11), and late endosome (Rab7), are maintained near neutral pH, do not fuse with lysosomes, exclude the protease cathepsin L, and engage the endoplasmic reticulum and Golgi apparatus for up to 21 days postinfection. Maintenance of this safe vacuolar niche requires activeA. marginaleprotein synthesis; in its absence, the AmVs mature into acidic, protease-active phagolysosomes. Identification of this bacterially directed modeling of the tick midgut endosome provides a mechanistic basis for examination of the differences in transmission efficiency observed amongA. marginalestrains and among vector populations.IMPORTANCETicks transmit a variety of intracellular bacterial pathogens that cause significant diseases in humans and animals. For successful transmission, these bacterial pathogens must first gain entry into the tick midgut digestive cells, avoid digestion, and establish a replicative niche without harming the tick vector. Little is known about how this replicative niche is established and maintained. Using the ruminant pathogenA. marginaleand its natural tick vector,D. andersoni, this study characterized the features of theA. marginaleniche in the tick midgut and demonstrates thatA. marginaleprotein synthesis is required for the maintenance of this niche. This work opens a new line of inquiry about the pathogen effectors and their targets within the tick that mediate tick-pathogen interactions and ultimately serve as the determinants of pathogen success.
Vibrio anguillarum Is Genetically and Phenotypically Unaffected by Long-Term Continuous Exposure to the Antibacterial Compound Tropodithietic Acid
Authors: Rasmussen Bastian Barker , Grotkjær Torben , D'Alvise Paul W. , Yin Guangliang , Zhang Faxing , Bunk Boyke , Spröer Cathrin , Bentzon-Tilia Mikkel , Gram Lone 
Published: May 2016

ABSTRACT

Minimizing the use of antibiotics in the food production chain is essential for limiting the development and spread of antibiotic-resistant bacteria. One alternative intervention strategy is the use of probiotic bacteria, and bacteria of the marine
Roseobacter
clade are capable of antagonizing fish-pathogenic vibrios in fish larvae and live feed cultures for fish larvae. The antibacterial compound tropodithietic acid (TDA), an antiporter that disrupts the proton motive force, is key in the antibacterial activity of several roseobacters. Introducing probiotics on a larger scale requires understanding of any potential side effects of long-term exposure of the pathogen to the probionts or any compounds they produce. Here we exposed the fish pathogen
Vibrio anguillarum
to TDA for several hundred generations in an adaptive evolution experiment. No tolerance or resistance arose during the 90 days of exposure, and whole-genome sequencing of TDA-exposed lineages and clones revealed few mutational changes, compared to lineages grown without TDA. Amino acid-changing mutations were found in two to six different genes per clone; however, no mutations appeared unique to the TDA-exposed lineages or clones. None of the virulence genes of
V. anguillarum
was affected, and infectivity assays using fish cell lines indicated that the TDA-exposed lineages and clones were less invasive than the wild-type strain. Thus, long-term TDA exposure does not appear to result in TDA resistance and the physiology of
V. anguillarum
appears unaffected, supporting the application of TDA-producing roseobacters as probiotics in aquaculture.

IMPORTANCE
It is important to limit the use of antibiotics in our food production, to reduce the risk of bacteria developing antibiotic resistance. We showed previously that marine bacteria of the
Roseobacter
clade can prevent or reduce bacterial diseases in fish larvae, acting as probiotics. Roseobacters produce the antimicrobial compound tropodithietic acid (TDA), and we were concerned regarding whether long-term exposure to this compound could induce resistance or affect the disease-causing ability of the fish pathogen. Therefore, we exposed the fish pathogen
Vibrio anguillarum
to increasing TDA concentrations over 3 months. We did not see the development of any resistance to TDA, and subsequent infection assays revealed that none of the TDA-exposed clones had increased virulence toward fish cells. Hence, this study supports the use of roseobacters as a non-risk-based disease control measure in aquaculture.
Distance-Decay Relationship for Biological Wastewater Treatment Plants
Authors: Wang Xiaohui , Wen Xianghua , Deng Ye , Xia Yu , Yang Yunfeng , Zhou Jizhong 
Published: May 2016

ABSTRACT

Patterns in the spatial distribution of organisms provide important information about mechanisms underlying biodiversity and the complexity of ecosystems. One of the most well-documented spatial patterns is the distance-decay relationship, which is a universal biogeographic pattern observed repeatedly for plant and animal communities, particularly for microorganisms in natural ecosystems such as soil, ocean, and salt marsh sediment. However, it is uncertain whether the microorganisms exhibit a distance-decay pattern in engineered ecosystems. Therefore, we measured the distance-decay relationship across various microbial functional and phylogenetic groups in 26 biological wastewater treatment plants (WWTPs) in China using a functional gene array (GeoChip 4.2). We found that microbial communities of activated sludge in WWTPs exhibited a significant but very weak distance-decay relationship. The taxon-area
z
values for different functional and phylogenetic groups were <0.0065, which is about 1 to 2 orders of magnitude lower than those observed in microbial communities elsewhere. Variation-partitioning analysis (VPA) showed that the relationships were driven by both environmental heterogeneity and geographic distance. Collectively, these results provided new insights into the spatial scaling of microbial communities in engineering ecosystems and highlighted the importance of environmental heterogeneity and geographic distance in shaping biogeographic patterns.

IMPORTANCE
Determining the distance-decay relationship of microbial biodiversity is important but challenging in microbial ecology. All studies to date are based on natural environments; thus, it remains unclear whether there is such a relationship in an engineered ecosystem. The present study shows that there is a very weak distance-decay relationship in an engineered ecosystem (WWTPs) at the regional-to-continental scale. This study makes fundamental contributions to a mechanistic, predictive understanding of microbial biogeography.
Phytophthora Species in Rivers and Streams of the Southwestern United States
Authors: Stamler Rio A. , Sanogo Soumalia , Goldberg Natalie P. , Randall Jennifer J. 
Published: May 2016

ABSTRACT

Phytophthora
species were isolated from rivers and streams in the southwestern United States by leaf baiting and identified by sequence analysis of internal transcribed spacer (ITS) ribosomal DNA (rDNA). The major waterways examined included the Rio Grande River, Gila River, Colorado River, and San Juan River. The most prevalent species identified in rivers and streams were
Phytophthora lacustris
and
P. riparia
, both members of
Phytophthora
ITS clade 6.
P. gonapodyides
,
P. cinnamomi
, and an uncharacterized
Phytophthora
species in clade 9 were also recovered. In addition, six isolates recovered from the Rio Grande River were shown to be hybrids of
P. lacustris
×
P. riparia
. Pathogenicity assays using
P. riparia
and
P. lacustris
failed to produce any disease symptoms on commonly grown crops in the southwestern United States. Inoculation of
Capsicum annuum
with
P. riparia
was shown to inhibit disease symptom development when subsequently challenged with
P. capsici
, a pathogenic
Phytophthora
species.

IMPORTANCE
Many
Phytophthora
species are significant plant pathogens causing disease on a large variety of crops worldwide. Closer examinations of streams, rivers, and forest soils have also identified numerous
Phytophthora
species that do not appear to be phytopathogens and likely act as early saprophytes in aquatic and saturated environments. To date, the
Phytophthora
species composition in rivers and streams of the southwestern United States has not been evaluated. This article details a study to determine the identity and prevalence of
Phytophthora
species in rivers and streams located in New Mexico, Arizona, Colorado, Utah, and Texas. Isolated species were evaluated for pathogenicity on crop plants and for their potential to act as biological control agents.
Effects of Bacterial Community Members on the Proteome of the Ammonia-Oxidizing Bacterium Nitrosomonas sp. Strain Is79
Authors: Sedlacek Christopher J. , Nielsen Susanne , Greis Kenneth D. , Haffey Wendy D. , Revsbech Niels Peter , Ticak Tomislav , Laanbroek Hendrikus J. , Bollmann Annette 
Published: May 2016

ABSTRACTMicroorganisms in the environment do not exist as the often-studied pure cultures but as members of complex microbial communities. Characterizing the interactions within microbial communities is essential to understand their function in both natural and engineered environments. In this study, we investigated how the presence of a nitrite-oxidizing bacterium (NOB) and heterotrophic bacteria affect the growth and proteome of the chemolithoautotrophic ammonia-oxidizing bacterium (AOB)Nitrosomonassp. strain Is79. We investigatedNitrosomonassp. Is79 in co-culture withNitrobacter winogradskyi, in co-cultures with selected heterotrophic bacteria, and as a member of the nitrifying enrichment culture G5-7. In batch culture,N. winogradskyiand heterotrophic bacteria had positive effects on the growth ofNitrosomonassp. Is79. An isobaric tag for relative and absolute quantification (iTRAQ) liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was used to investigate the effect ofN. winogradskyiand the co-cultured heterotrophic bacteria from G5-7 on the proteome ofNitrosomonassp. Is79. In co-culture withN. winogradskyi, severalNitrosomonassp. Is79 oxidative stress response proteins changed in abundance, with periplasmic proteins increasing and cytoplasmic proteins decreasing in abundance. In the presence of heterotrophic bacteria, the abundance of proteins directly related to the ammonia oxidation pathway increased, while the abundance of proteins related to amino acid synthesis and metabolism decreased. In summary, the proteome ofNitrosomonassp. Is79 was differentially influenced by the presence of eitherN. winogradskyior heterotrophic bacteria. Together,N. winogradskyiand heterotrophic bacteria reduced the oxidative stress forNitrosomonassp. Is79, which resulted in more efficient metabolism.IMPORTANCEAerobic ammonia-oxidizing microorganisms play an important role in the global nitrogen cycle, converting ammonia to nitrite. In their natural environment, they coexist and interact with nitrite oxidizers, which convert nitrite to nitrate, and with heterotrophic microorganisms. The presence of nitrite oxidizers and heterotrophic bacteria has a positive influence on the growth of the ammonia oxidizers. Here, we present a study investigating the effect of nitrite oxidizers and heterotrophic bacteria on the proteome of a selected ammonia oxidizer in a defined culture to elucidate how these two groups improve the performance of the ammonia oxidizer. The results show that the presence of a nitrite oxidizer and heterotrophic bacteria reduced the stress for the ammonia oxidizer and resulted in more efficient energy generation. This study contributes to our understanding of microbe-microbe interactions, in particular between ammonia oxidizers and their neighboring microbial community.
Evidence for a Role for the Plasma Membrane in the Nanomechanical Properties of the Cell Wall as Revealed by an Atomic Force Microscopy Study of the Response of Saccharomyces cerevisiae to Ethanol Stress
Authors: Schiavone Marion , Formosa-Dague Cécile , Elsztein Carolina , Teste Marie-Ange , Martin-Yken Helene , De Morais Marcos A. , Dague Etienne , François Jean M. 
Published: May 2016

ABSTRACT

A wealth of biochemical and molecular data have been reported regarding ethanol toxicity in the yeast
Saccharomyces cerevisiae
. However, direct physical data on the effects of ethanol stress on yeast cells are almost nonexistent. This lack of information can now be addressed by using atomic force microscopy (AFM) technology. In this report, we show that the stiffness of glucose-grown yeast cells challenged with 9% (vol/vol) ethanol for 5 h was dramatically reduced, as shown by a 5-fold drop of Young's modulus. Quite unexpectedly, a mutant deficient in the Msn2/Msn4 transcription factor, which is known to mediate the ethanol stress response, exhibited a low level of stiffness similar to that of ethanol-treated wild-type cells. Reciprocally, the stiffness of yeast cells overexpressing
MSN2
was about 35% higher than that of the wild type but was nevertheless reduced 3- to 4-fold upon exposure to ethanol. Based on these and other data presented herein, we postulated that the effect of ethanol on cell stiffness may not be mediated through Msn2/Msn4, even though this transcription factor appears to be a determinant in the nanomechanical properties of the cell wall. On the other hand, we found that as with ethanol, the treatment of yeast with the antifungal amphotericin B caused a significant reduction of cell wall stiffness. Since both this drug and ethanol are known to alter, albeit by different means, the fluidity and structure of the plasma membrane, these data led to the proposition that the cell membrane contributes to the biophysical properties of yeast cells.

IMPORTANCE
Ethanol is the main product of yeast fermentation but is also a toxic compound for this process. Understanding the mechanism of this toxicity is of great importance for industrial applications. While most research has focused on genomic studies of ethanol tolerance, we investigated the effects of ethanol at the biophysical level and found that ethanol causes a strong reduction of the cell wall rigidity (or stiffness). We ascribed this effect to the action of ethanol perturbing the cell membrane integrity and hence proposed that the cell membrane contributes to the cell wall nanomechanical properties.
Regulation of the Cobalt/Nickel Efflux OperondmeRFin Agrobacterium tumefaciens and a Link between the Iron-Sensing Regulator RirA and Cobalt/Nickel Resistance
Authors: Dokpikul Thanittra , Chaoprasid Paweena , Saninjuk Kritsakorn , Sirirakphaisarn Sirin , Johnrod Jaruwan , Nookabkaew Sumontha , Sukchawalit Rojana , Mongkolsuk Skorn 
Published: May 2016

ABSTRACTTheAgrobacterium tumefaciensC58 genome harbors an operon containing thedmeR(Atu0890) anddmeF(Atu0891) genes, which encode a transcriptional regulatory protein belonging to the RcnR/CsoR family and a metal efflux protein belonging to the cation diffusion facilitator (CDF) family, respectively. ThedmeRFoperon is specifically induced by cobalt and nickel, with cobalt being the more potent inducer. Promoter-lacZtranscriptional fusion, an electrophoretic mobility shift assay, and DNase I footprinting assays revealed that DmeR repressesdmeRFtranscription through direct binding to the promoter region upstream ofdmeR. A strain lackingdmeFshowed increased accumulation of intracellular cobalt and nickel and exhibited hypersensitivity to these metals; however, this strain displayed full virulence, comparable to that of the wild-type strain, when infecting aNicotiana benthamianaplant model under the tested conditions. Cobalt, but not nickel, increased the expression of many iron-responsive genes and reduced the induction of the SoxR-regulated genesodBII. Furthermore, control of iron homeostasis via RirA is important for the ability ofA. tumefaciensto cope with cobalt and nickel toxicity.IMPORTANCEThe molecular mechanism of the regulation ofdmeRFtranscription by DmeR was demonstrated. This work provides evidence of a direct interaction of apo-DmeR with the corresponding DNA operator siteinvitro. The recognition site for apo-DmeR consists of 10-bp AT-rich inverted repeats separated by six C bases (5′-ATATAGTATACCCCCCTATAGTATAT-3′). Cobalt and nickel cause DmeR to dissociate from thedmeRFpromoter, which leads to expression of the metal efflux genedmeF. This work also revealed a connection between iron homeostasis and cobalt/nickel resistance inA. tumefaciens.
The role of financial hardship, mastery and social support in the association between employment status and depression: results from an Australian longitudinal cohort study
Authors: Crowe Laura , Butterworth Peter 
Published: May 2016

ObjectiveThere is robust epidemiological and clinical evidence of the harmful effects of unemployment on psychological well-being, but the mechanisms through which this occurs is still strongly debated. In addition, there is even less evidence on the impact of underemployment on mental health. Using longitudinal data collected from a cohort of 20–24 years old, the present study examines a range of employed states and investigates the role of mastery, financial hardship and social support in the relationship between labour status and depression.MethodResponses were from the Personality and Total Health (PATH) Through Life Project: A representative, community-based survey conducted in Canberra and Queanbeyan (NSW) in Australia, where respondents (n=2404) in their early twenties were followed for 8 years. Depression was measured using the self-report Goldberg Depression Scale, with the likely presence of depression being indicated by scores 7 or greater.ResultsThe analyses identified unemployment and underemployment as significant predictors of depression, compared to their employed counterparts. Both unemployment and underemployment remained significantly correlated with depression even after accounting for sociodemographic, economic and psychological variables. Social support, financial hardship and a sense of personal control (mastery) all emerged as important mediators between unemployment and depression.ConclusionsBoth unemployment and underemployment were associated with increased risk of depression. The strength of this relationship was attenuated but remained significant after accounting for key variables (mastery, financial hardship and social support), and extensive sociodemographic and health covariates, indicating that no or inade­quate employment contributes to poorer mental health over and above these factors.
Protocol for a pragmatic cluster randomised controlled trial for reducing irrational antibiotic prescribing among children with upper respiratory infections in rural China
Authors: Zou Guanyang , Wei Xiaolin , Hicks Joseph P , Hu Yanhong , Walley John , Zeng Jun , Elsey Helen , King Rebecca , Zhang Zhitong , Deng Simin , Huang Yuanyuan , Blacklock Claire , Yin Jia , Sun Qiang , Lin Mei 
Published: May 2016

IntroductionIrrational use of antibiotics is a serious issue within China and internationally. In 2012, the Chinese Ministry of Health issued a regulation for antibiotic prescriptions limiting them to <20% of all prescriptions for outpatients, but no operational details have been issued regarding policy implementation. This study aims to test the effectiveness of a multidimensional intervention designed to reduce the use of antibiotics among children (aged 2–14 years old) with acute upper respiratory infections in rural primary care settings in China, through changing doctors' prescribing behaviours and educating parents/caregivers.Methods and analysisThis is a pragmatic, parallel-group, controlled, cluster-randomised superiority trial, with blinded evaluation of outcomes and data analysis, and un-blinded treatment. From two counties in Guangxi Province, 12 township hospitals will be randomised to the intervention arm and 13 to the control arm. In the control arm, the management of antibiotics prescriptions will continue through usual care via clinical consultations. In the intervention arm, a provider and patient/caregiver focused intervention will be embedded within routine primary care practice. The provider intervention includes operational guidelines, systematic training, peer review of antibiotic prescribing and provision of health education to patient caregivers. We will also provide printed educational materials and educational videos to patients' caregivers. The primary outcome is the proportion of all prescriptions issued by providers for upper respiratory infections in children aged 2–14 years old, which include at least one antibiotic.Ethics and disseminationThe trial has received ethical approval from the Ethics Committee of Guangxi Provincial Centre for Disease Control and Prevention, China. The results will be disseminated through workshops, policy briefs, peer-reviewed publications, local and international conferences.Trial registration numberISRCTN14340536; Pre-results.