Iron Acquisition Mechanisms and Their Role in the Virulence of Burkholderia Species

Burkholderia is a genus within the β-Proteobacteriaceae that contains at least 90 validly named species which can be found in a diverse range of environments. A number of pathogenic species occur within the genus. These include Burkholderia cenocepacia and Burkholderia multivorans, opportunistic pathogens that can infect the lungs of patients with cystic fibrosis, and are members of the Burkholderia cepacia complex (Bcc). Burkholderia pseudomallei is also an opportunistic pathogen, but in contrast to Bcc species it causes the tropical human disease melioidosis, while its close relative Burkholderia mallei is the causative agent of glanders in horses. For these pathogens to survive within a host and cause disease they must be able to acquire iron. This chemical element is essential for nearly all living organisms due to its important role in many enzymes and metabolic processes. In the mammalian host, the amount of accessible free iron is negligible due to the low solubility of the metal ion in its higher oxidation state and the tight binding of this element by host proteins such as ferritin and lactoferrin. As with other pathogenic bacteria, Burkholderia species have evolved an array of iron acquisition mechanisms with which to capture iron from the host environment. These mechanisms include the production and utilization of siderophores and the possession of a haem uptake system. Here, we summarize the known mechanisms of iron acquisition in pathogenic Burkholderia species and discuss the evidence for their importance in the context of virulence and the establishment of infection in the host. We have also carried out an extensive bioinformatic analysis to identify which siderophores are produced by each Burkholderia species that is pathogenic to humans

Effect of Calcium Chloride and Trisodium Phosphate Fortification on Low Fat Buffalo Milk Cheeses

Cheese is a dairy product that is highly preferred by consumers. Cheese is a delectable and nutritious food item. Enhancing the quality of cheese necessitates innovation in cheese processing. The objective of the study was to determine the impact of calcium chloride and trisodium phosphate on the physical, chemical, microbiological, and rheological characteristics (namely firmness) of low-fat buffalo milk cheeses. This study had a fully randomized design, consisting of nine treatments and three replications. The cottage cheese, mozzarella, and cheddar were treated with varying quantities of calcium chloride and trisodium phosphate (10, 20, and 30 mM) and then stored for a period of 30 days. The cheeses supplemented with salt exhibited a noteworthy (p≤0.05) rise in pH, total nitrogen (TN), non-casein nitrogen (NCN), and non-protein nitrogen (NPN) for nearly all treatments. However, a subsequent decline was noted after storage. Similarly, the hardness (N) significantly improved (from 330.33 to 454) among treatments and reduced (from 427 to 276.33) after 30 days of storage, with a p-value of ≤0.05. In addition, the total plate count (TPC) and total viable count (TVC) showed an upward trend during the ripening phase. In conclusion, it was observed that the physicochemical, rheological, and microbiological quality characteristics of cheeses can be effectively regulated with appropriate mineral fortification

Comparison of physical activity levels and dietary habits between women with polycystic ovarian syndrome and healthy controls of reproductive age: A case-control study

BackgroundPolycystic ovarian syndrome (PCOS) is a reproductive hormonal anomaly prevalent among women of reproductive age, with an alarmingly high prevalence of 52% among Pakistani women. This study aims to compare the daily physical activity and dietary habits of women with PCOS with age-matched healthy controls living in Lahore, Pakistan.MethodsA case–control study design was used to collect data from a private hospital situated in Lahore, Pakistan. Data was collected from 115 participants of reproductive age (18–45 years) using a researcher-administered questionnaire. Demographic variables, reproductive characteristics, anthropometric measurements, and seven days of physical activity levels using the international physical activity questionnaire (IPAQ-Short version) and seven days of dietary intake using the food frequency questionnaire (7 days-FFQ) were used to measure the dietary habits of the participants. Mosby’s Nutritac v4.0 software was used to estimate the macronutrients, vitamins, and minerals present in dietary intake. The glycaemic index and glycaemic load were calculated to compare the quality and quantity of carbohydrate consumption between the two groups.ResultsThe 49 PCOS cases, newly identified using the Rotterdam criteria, mean age 24.63 years (SD ± 4.76), and 66 healthy controls, mean age 23.24 years (SD ± 5.45), were compared. A significant difference (p ≤ 0.05) was found for reproductive characteristics, daily physical activity, and polyunsaturated fat and vitamin intake between the two groups. A binary logistic regression analysis showed that food with a low glycaemic index (GI ≤ 40) reduced the odds of PCOS occurrence by OR = 1.94. Similarly, food nutrients with a low glycaemic load (GL ≤ 10) can reduce PCOS occurrence by OR = 1.60.ConclusionThe daily physical activity levels and dietary habits of women of reproductive age can influence their reproductive characteristics and polycystic ovarian morphology. A diet with a low glycaemic load and index can produce beneficial reproductive health effects among women of reproductive age.<br/

Serum anti-Müllerian hormone as a predictor of polycystic ovarian syndrome among women of reproductive age

BackgroundPolycystic ovarian syndrome (PCOS) affects up to one-fifth of women of reproductive age and causes anovulatory subfertility. Some studies have recommended that an anti-Müllerian hormone (AMH) level greater than 3.8–5 ng/mL can be used for diagnosing PCOS. This study aims to analyse serum AMH levels among PCOS women of reproductive age to use AMH as a biomarker predictor along with other Rotterdam criteria.MethodsIn this cross-sectional study, a total of 98 women visiting the fertility center of a private hospital in Lahore, Pakistan, were screened. Data were obtained from 51 PCOS newly diagnosed women aged 28.24 years (SD ± 4.84 years) meeting at least two of the Rotterdam criteria and specific inclusion criteria. Baseline variables, menstrual cycle length, ovarian morphology on ultrasound, hirsutism, sex hormones, gonadotropin, and serum AMH levels were analysed during the follicular phase (1–5 days) of the menstrual cycle. Serum AMH was measured by an enzyme-linked immunosorbent assay.ResultsA high serum AMH level (7.23 ± 4.67 ng/ml) was recorded with normal sex hormone levels. Women with oligo-/amenorrhea had a significant mean difference for luteinizing hormone (p = 0.02) and AMH levels (p = 0.03) when compared with women of normal menstrual cycle length. PCOS women with high AMH levels (≥ 3.9 ng/ml) showed a significant difference in ovarian morphology (p &lt; 0.05) when compared with the normal AMH group.ConclusionsAn elevated serum AMH level can be used as a strong predictor to reflect the certainty of PCOS diagnosis among women of reproductive age when study concurrently with the other Rotterdam criteria

Active Brownian Particles. From Individual to Collective Stochastic Dynamics

We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

Oral health perceptions and practices of caregivers at children’s religious schools and foster care centers: a qualitative exploratory study in Lahore, Pakistan

BackgroundOral diseases are one of the major public health problems worldwide and affect the population of all age groups. This qualitative study aimed to explore the perceptions and practices of caregivers at care centres and boarding religious schools responsible for managing children’s oral health.MethodsA qualitative ethnomethodological approach was used to collect data from the caregivers at the children’s religious schools and foster care centres. A purposive sampling technique was used to conduct focus group discussions comprising 4–7 caregivers from five foster care centres and religious schools located in Lahore, Pakistan.An interview guide was developed based on results from previous studies. An inductive approach was used to analyse data on broader oral health concepts to generate themes in this qualitative research. A three-step thematic analysis was applied to develop codes that were merged to generate categories and to conclude into themes from the transcribed data. Five focus group discussions were conducted at two foster care centres (FG1 &amp; FG2) and three religious schools (FG3, FG4 &amp; FG5). Foster care centres had children of both gender within the same premises; however, religious schools had segregated settings.ResultsThe following four themes emerged from the thematic analysis: development of the desired living environment and responsibilities of the caregivers, preexisting traditional personal knowledge of the caregivers determine children’s oral health, use of religio-cultural driven and convenience-based oral hygiene practices, and ethnomedicine, spiritual healing, and self-medication. Development and the existing living environment of the foster care centres and religious schools appeared important to manage the matters of the boarding children.ConclusionsThis qualitative study concludes that the oral health of the children at foster care centres and at religious schools depends upon the personal reasoning and pre-existing religio-cultural knowledge of the caregivers rather than on specialized oral health-oriented approaches. The foster care centres are more involved in supervising the children to maintain oral hygiene and oral health compared to religious schools.<br/

Distinct modes of promoter recognition by two iron starvation σ factors with overlapping promoter specificities

OrbS and PvdS are extracytoplasmic function (ECF) σ factors that regulate transcription of operons required for the biosynthesis of the siderophores ornibactin and pyoverdine in the B. cepacia complex and Pseudomonas spp., respectively. Here we show that promoter recognition by OrbS requires specific tetrameric -35 and -10 element sequences that are strikingly similar to those of the consensus PvdS-dependent promoter. However, whereas P. aeruginosa PvdS can serve OrbS-dependent promoters, OrbS cannot utilise PvdS-dependent promoters. To identify features present at OrbS-dependent promoters that facilitate recognition by OrbS, we carried out a detailed analysis of the nucleotide sequence requirements for promoter recognition by both OrbS and PvdS. This revealed that DNA sequence features located outside of the sigma binding elements are required for efficient promoter utilisation by OrbS. In particular, the presence of an A-tract extending downstream from the -35 element at OrbS-dependent promoters was shown to be an important contributor to OrbS specificity. Our observations demonstrate that the nature of the spacer sequence can have a major impact on promoter recognition by some ECF sigma factors through modulation of the local DNA architecture

Insect pathogens as biological control agents: back to the future

The development and use of entomopathogens as classical, conservation and augmentative biological control agents have included a number of successes and some setbacks in the past 15 years. In this forum paper we present current information on development, use and future directions of insect-specific viruses, bacteria, fungi and nematodes as components of integrated pest management strategies for control of arthropod pests of crops, forests, urban habitats, and insects of medical and veterinary importance. Insect pathogenic viruses are a fruitful source of MCAs, particularly for the control of lepidopteran pests. Most research is focused on the baculoviruses, important pathogens of some globally important pests for which control has become difficult due to either pesticide resistance or pressure to reduce pesticide residues. Baculoviruses are accepted as safe, readily mass produced, highly pathogenic and easily formulated and applied control agents. New baculovirus products are appearing in many countries and gaining an increased market share. However, the absence of a practical in vitro mass production system, generally higher production costs, limited post application persistence, slow rate of kill and high host specificity currently contribute to restricted use in pest control. Overcoming these limitations are key research areas for which progress could open up use of insect viruses to much larger markets. A small number of entomopathogenic bacteria have been commercially developed for control of insect pests. These include several Bacillus thuringiensis sub-species, Lysinibacillus (Bacillus) sphaericus, Paenibacillus spp. and Serratia entomophila. B. thuringiensis sub-species kurstaki is the most widely used for control of pest insects of crops and forests, and B. thuringiensis sub-species israelensis and L. sphaericus are the primary pathogens used for medically important pests including dipteran vectors,. These pathogens combine the advantages of chemical pesticides and microbial control agents (MCAs): they are fast acting, easy to produce at a relatively low cost, easy to formulate, have a long shelf life and allow delivery using conventional application equipment and systemics (i.e. in transgenic plants). Unlike broad spectrum chemical pesticides, B. thuringiensis toxins are selective and negative environmental impact is very limited. Of the several commercially produced MCAs, B. thuringiensis (Bt) has more than 50% of market share. Extensive research, particularly on the molecular mode of action of Bt toxins, has been conducted over the past two decades. The Bt genes used in insect-resistant transgenic crops belong to the Cry and vegetative insecticidal protein families of toxins. Bt has been highly efficacious in pest management of corn and cotton, drastically reducing the amount of broad spectrum chemical insecticides used while being safe for consumers and non-target organisms. Despite successes, the adoption of Bt crops has not been without controversy. Although there is a lack of scientific evidence regarding their detrimental effects, this controversy has created the widespread perception in some quarters that Bt crops are dangerous for the environment. In addition to discovery of more efficacious isolates and toxins, an increase in the use of Bt products and transgenes will rely on innovations in formulation, better delivery systems and ultimately, wider public acceptance of transgenic plants expressing insect-specific Bt toxins. Fungi are ubiquitous natural entomopathogens that often cause epizootics in host insects and possess many desirable traits that favor their development as MCAs. Presently, commercialized microbial pesticides based on entomopathogenic fungi largely occupy niche markets. A variety of molecular tools and technologies have recently allowed reclassification of numerous species based on phylogeny, as well as matching anamorphs (asexual forms) and teleomorphs (sexual forms) of several entomopathogenic taxa in the Phylum Ascomycota. Although these fungi have been traditionally regarded exclusively as pathogens of arthropods, recent studies have demonstrated that they occupy a great diversity of ecological niches. Entomopathogenic fungi are now known to be plant endophytes, plant disease antagonists, rhizosphere colonizers, and plant growth promoters. These newly understood attributes provide possibilities to use fungi in multiple roles. In addition to arthropod pest control, some fungal species could simultaneously suppress plant pathogens and plant parasitic nematodes as well as promote plant growth. A greater understanding of fungal ecology is needed to define their roles in nature and evaluate their limitations in biological control. More efficient mass production, formulation and delivery systems must be devised to supply an ever increasing market. More testing under field conditions is required to identify effects of biotic and abiotic factors on efficacy and persistence. Lastly, greater attention must be paid to their use within integrated pest management programs; in particular, strategies that incorporate fungi in combination with arthropod predators and parasitoids need to be defined to ensure compatibility and maximize efficacy. Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis are potent MCAs. Substantial progress in research and application of EPNs has been made in the past decade. The number of target pests shown to be susceptible to EPNs has continued to increase. Advancements in this regard primarily have been made in soil habitats where EPNs are shielded from environmental extremes, but progress has also been made in use of nematodes in above-ground habitats owing to the development of improved protective formulations. Progress has also resulted from advancements in nematode production technology using both in vivo and in vitro systems; novel application methods such as distribution of infected host cadavers; and nematode strain improvement via enhancement and stabilization of beneficial traits. Innovative research has also yielded insights into the fundamentals of EPN biology including major advances in genomics, nematode-bacterial symbiont interactions, ecological relationships, and foraging behavior. Additional research is needed to leverage these basic findings toward direct improvements in microbial control

Measurement of the correlation between flow harmonics of different order in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector

Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using √sNN=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 μb−1. The vm−vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistent with similar anticorrelations between the corresponding eccentricities, ε2 and ε3. However, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm−vn correlations for n=4 and 5 are found to disagree with εm−εn correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations

Search for W′→tb→qqbb decays in pp collisions at √s=8 TeV with the ATLAS detector

A search for a massive W′ gauge boson decaying to a top quark and a bottom quark is performed with the ATLAS detector in pp collisions at the LHC. The dataset was taken at a centre-of-mass energy of √s=8 TeV and corresponds to 20.3 fb−1 of integrated luminosity. This analysis is done in the hadronic decay mode of the top quark, where novel jet substructure techniques are used to identify jets from high-momentum top quarks. This allows for a search for high-mass W′ bosons in the range 1.5–3.0 TeV. b-tagging is used to identify jets originating from b-quarks. The data are consistent with Standard Model background-only expectations, and upper limits at 95 % confidence level are set on the W′→tb cross section times branching ratio ranging from 0.16pb to 0.33pb for left-handed W′ bosons, and ranging from 0.10pb to 0.21pb for W′ bosons with purely right-handed couplings. Upper limits at 95 % confidence level are set on the W′-boson coupling to tb as a function of the W′ mass using an effective field theory approach, which is independent of details of particular models predicting a W′boson