The proteome of extracellular vesicles produced by the human gut bacteria bacteroides thetaiotaomicron in vivo Is influenced by environmental and host-derived factors

Bacterial extracellular vesicles (BEVs) released from both Gram-negative and Gram-positive bacteria provide an effective means of communication and trafficking of cell signaling molecules. In the gastrointestinal tract (GIT) BEVs produced by members of the intestinal microbiota can impact host health by mediating microbe-host cell interactions. A major unresolved question, however, is what factors influence the composition of BEV proteins and whether the host influences protein packaging into BEVs and secretion into the GIT. To address this, we have analyzed the proteome of BEVs produced by the major human gut symbiont Bacteroides thetaiotaomicron both in vitro and in vivo in the murine GIT in order to identify proteins specifically enriched in BEVs produced in vivo. We identified 113 proteins enriched in BEVs produced in vivo, the majority (62/113) of which accumulated in BEVs in the absence of any changes in their expression by the parental cells. Among these selectively enriched proteins, we identified dipeptidyl peptidases and an asparaginase and confirmed their increased activity in BEVs produced in vivo. We also showed that intact BEVs are capable of degrading bile acids via a bile salt hydrolase. Collectively these findings provide additional evidence for the dynamic interplay of host-microbe interactions in the GIT and the existence of an active mechanism to drive and enrich a selected group of proteins for secretion into BEVs in the GIT

Biological control against invasive species in simplified ecosystems: Its triumphs and emerging threats

Although records show that the loss of susceptibility of pests to biological control agents is an exceedingly rare event, there are certain behavioural and ecological settings that may well predispose to it. In general, these circumstances rarely converge. Such a critical combination of factors could possibly occur in agroecosystems based on incomplete transplants imported from elsewhere. It can be argued that such ecosystems lack the biodiversity required to confer biotic resistance to invasive species and this can result in spectacularly high and damaging pest densities. Through exactly the same mechanism, introduced control agents such as parasitoid wasps, similarly can prove to be very successful in producing persistently very high levels of parasitism of pests, leading to triumph. However, this feeling may be short-lived. When success is based on very high selection pressure on the host pest species this could have the potential to lead to the evolution of resistance to the control agent. This is particularly so should it coincide with factors such as a lack of pest host refugia, parasitoid parthenogenetic reproduction, versus pest sexual reproduction, as well as suppression based on a narrow range of natural enemies. In effect, the very thing that can lead to spectacular success can eventually become the basis for failure. For the purposes of illustration, these considerations are illustrated via what seems to be a developing cause for concern about biological control in New Zealand's pastures

Se-methylselenocysteine alters collagen gene and protein expression in human prostate cells.

The anti-cancer activity of selenium is dose-dependent and species-specific but the mechanism is unclear. Se-methylselenocysteine (MSC), found in selenium-enriched alliums, is one of the most potent forms. We exposed two human prostate cell lines (LNCaP clone FGC and PNT1A) to nutritionally relevant doses of MSC and selenite, ranging from deficient to the equivalent of selenium supplementation in humans. The cells were adapted for one month to attain steady-state selenium status. Two microarray platforms, an in-house printed microarray (14,000 genes) and the Affymetrix U133A array (22,000 genes) were used to probe the molecular effects of selenium dose and form and several selenium-responsive genes were identified, many of which have been ascribed to cancer cell growth and progression. In response to MSC supplementation, the expression of 23 genes changed significantly, including several collagen genes. Quantitative RT-PCR assays were designed and optimized for four of the collagen genes to validate array data. Significant decreases in expression of collagen type I alpha 1 (COL1A1), COL1A2 and COL7A1 genes were observed in cells adapted to MSC supplementation compared to the control and selenite exposed cells. There were significant increases in genes encoding other types of collagen, including significant increases in COL6A1 and COL4A5 in response to MSC dose. Functional changes in collagen type I protein expression in response to MSC were confirmed by ELISA. This study reveals for the first time that MSC can alter the expression of several types of collagen and thus potentially modulate the extracellular matrix and stroma, which may at least partially explain the anti-cancer activity of MSC

Severe Insect Pest Impacts on New Zealand Pasture: The Plight of an Ecological Outlier

© The Author(s) 2020. New Zealand’s intensive pastures, comprised almost entirely introduced Lolium L. and Trifolium L. species, are arguably the most productive grazing-lands in the world. However, these areas are vulnerable to destructive invasive pest species. Of these, three of the most damaging pests are weevils (Coleoptera: Curculionidae) that have relatively recently been controlled by three different introduced parasitoids, all belonging to the genus Microctonus Wesmael (Hymenoptera: Braconidae). Arguably that these introduced parasitoids have been highly effective is probably because they, like many of the exotic pest species, have benefited from enemy release. Parasitism has been so intense that, very unusually, one of the weevils has now evolved resistance to its parthenogenetic parasitoid.This review argues that New Zealand’s high exotic pasture pest burden is attributable to a lack of pasture plant and natural enemy diversity that presents little biotic resistance to invasive species.There is a native natural enemy fauna in New Zealand that has evolved over millions of years of geographical isolation. However, these species remain in their indigenous ecosystems and, therefore, play a minimal role in creating biotic resistance in the country’s exotic ecosystems. For clear ecological reasons relating to the nature of New Zealand pastures, importation biological control can work extremely well. Conversely, conservation biological control is less likely to be effective than elsewhere

Severe insect pest impacts on New Zealand pasture: The plight of an ecological outlier

New Zealand’s intensive pastures, comprised almost entirely introduced Lolium L. and Trifolium L. species, are arguably the most productive grazing lands in the world. However, these areas are vulnerable to destructive invasive pest species. Of these, three of the most damaging pests are weevils (Coleoptera: Curculionidae) that have relatively recently been controlled by three different introduced parasitoids, all belonging to the genus Microctonus Wesmael (Hymenoptera: Braconidae). Arguably that these introduced parasitoids have been highly effective is probably because they, like many of the exotic pest species, have benefited from enemy release. Parasitism has been so intense that, very unusually, one of the weevils has now evolved resistance to its parthenogenetic parasitoid. This review argues that New Zealand’s high exotic pasture pest burden is attributable to a lack of pasture plant and natural enemy diversity that presents little biotic resistance to invasive species. There is a native natural enemy fauna in New Zealand that has evolved over millions of years of geographical isolation. However, these species remain in their indigenous ecosystems and, therefore, play a minimal role in creating biotic resistance in the country’s exotic ecosystems. For clear ecological reasons relating to the nature of New Zealand pastures, importation biological control can work extremely well. Conversely, conservation biological control is less likely to be effective than elsewhere

If and when successful classical biological control fails

Classical biological control of insects has a long history of success, with high benefit-cost ratios. However, most attempts to introduce a biological control agent have been unsuccessful, largely because the agent does not establish in the new environment. This perspectives paper discusses the possibility that even successful biological control may eventually fail, although records show that this is far from a common event. A documented example of eventual biological control failure is discussed and the prospect for future failures analyzed. Part of this analysis is based on an introduced weevil pest in New Zealand and its successful parasitoid biological control agent. The potential fragility of this host-parasitoid relationship is considered, as well as why it may indeed be starting to show signs of instability; this is particularly from the point of view of New Zealand's often species-poor agricultural ecosystems

Quantifying the economic cost of invertebrate pests to New Zealand’s pastoral industry

The invertebrate pests most commonly affecting New Zealand’s pastoral-based production in ‘average’ years cause losses of between $1.7B and$2.3B p.a. of which up to $0.9B occur on sheep and beef farms and$1.4B on dairy farms. The native scarab grass grub is the most costly pest causing losses of $140–380 M on dairy farms and$75–205 M on sheep and beef farms annually. The exotic scarab, black beetle, although only affecting approximately 1 M ha, costs dairy farmers up to $223 M and sheep and beef farmers up to$19 M annually. Porina cause losses up to $84 M and$88 M respectively. Pasture nematodes are estimated to cost up to $274 M p.a. for dairy farmers and$326 M p.a. for sheep and beef farmers. Two exotic pests, Argentine stem weevil (ASW) and clover root weevil (CRW) are causing damage estimated at up to $200 M p.a. and$235 M p.a. respectively in dairy and sheep and beef pastures. While CRW is subject to successful biological control management it still causes considerable losses. Lesser pests also contribute to lost production, particularly as they often coexist with more major pests. However, their economic cost to New Zealand is difficult to calculate due to the variable nature of infestations on both temporal and spatial scales. At farm and paddock level, it is abundantly clear that substantial savings could be made if pest management is achieved. It is equally clear that in many instances the tools to do so are limited but if developed would contribute substantially to farm profitability

Identifying children with Special Health Care Needs in Alexandria, Egypt

ObjectiveTo test the feasibility of using an Arabic version of CSHCN Screener in identifying CSHCN in the Egyptian setup and to estimate the prevalence of CSHCN among children aged 6-14 years in Alexandria, Egypt using the Arabic version of the CSHCN Screener.IntroductionChildren with special health care needs (CSHCN) are defined as: “those who have or are at increased risk for a chronic physical, developmental, behavioural, or emotional condition and who also require health and related services of a type or amount beyond that required by children generally.” (1) The care of CSHCN is a significant public health issue. These children are medically complex, require services and supports well beyond those that typically developing children require, and command a considerable proportion of the pediatric health care budget. (2)Different tools were used to identify CSHCN. (3, 4) One of them is the CSHCN screener (5) which uses a non-condition specific approach that identifies children across a range and diversity of childhood chronic conditions and special needs. (6) It identifies children with elevated or unusual needs for health care or educational services due to a chronic health condition. It focuses on health consequences a child experiences as a result of having an ongoing health condition rather than on the presence of a specific diagnosis or type of disability. It allows a more comprehensive assessment of the performance of the health care system than is attainable by focusing on a single diagnosis. (7) The CSHCN screener is only available in English and Spanish. (8)In developing countries, obtaining reliable prevalence rates for CSHCN is challenging. Sophisticated datasets associated with governmental services and high quality research studies are less common due to fewer resources. Egypt has no screening or surveillance systems for identifying CSHCN. (9)MethodsA community based survey was conducted among a representative sample of children aged 6-14 years from the 8 health districts of Alexandria, Egypt using a multistage cluster sampling technique. The final sample amounted to 501 children from 405 families. Data about the children and their families were collected by interviewing the mothers of the selected children using a pre-designed interviewing questionnaire. The questionnaire included their personal and family characteristics in addition to the Arabic translation of CSHCN screener. Permission to translate the questionnaire into the Arabic language was obtained from the Child and Adolescent Health Measurement Initiative. Validation and cultural adaptation of the translated CSHCN screener were done. The survey questions were generally understandable by Arabic speakers. As for the screener questions, the Arabic translation was straightforward and clear. The difference between the Arabic translation for the words “health conditions” and “medical conditions” in the 1st follow up questions was not clear for the respondents and the interviewers had to give an explanation for the two terms to help the respondents. So, it was easier for the respondents to answer the screener questions than the follow up questions.ResultsOut of the 501 children included in the study, 61 were identified by the screener to be CSHCN, making a prevalence of CSHCN of 12.2%. The prevalence of children with dependency on prescription medicine was 11.8%, while the prevalence of children with service use above that considered usual or routine was 11.8%. The prevalence of children with functional limitations was 12%. Among these domains, in almost all children, the reason was a medical, behavioral or health condition (98.3%) and the condition has continued or is expected to continue for at least 12 months in all children. Among CSHCN, the majority (91.8%) had these three domains combined.Sensory impairments ranked first among the most prevalent conditions requiring special health care with a prevalence of 2.8% which represented 23% of the conditions, followed by cognitive impairments with a prevalence of 2% representing 16.4% of all conditions requiring special health care. Impaired mobility was the third most common condition requiring special care with a prevalence of 1.8%.The table shows that CSHCN were more likely to be in the younger age group (6-<10 years), to be males, to be the first in order among their siblings and to have an illiterate or just read and write father. On the other hand, CSHCN were less likely to have a university educated mother, to be living with both parents and to be from a family without an enough income. The only significant factor was the type of family (cOR=0.88, 95% CI = 0.85-0.91).ConclusionsThe study showed the feasibility to use the CSHCN screener in the Egyptian National health care services to easily identify the majority of children that need to be the focus of the National health care services. It could also be an easy tool to assess the quality of the ongoing school health programs in responding to the overall needs of school children.With the present Egyptian policy of reform giving special attention to people in need particularly sensitive groups such as school children, it is therefore recommended that the school health services, in addition to the ongoing diagnostic, preventive and curative services add an additional measure, namely the screener for CSHCN, which is a simple easily administered screening tool which will also assist to depict existing gaps in the health care system to ensure being comprehensive.ReferencesMcPherson M, Arango P, Fox C, et al. A new definition of children with special health care needs. Pediatrics 1998;102:137-40.Goldson E, Louch G, Washington K, et al. Guidelines for the care of the child with special health care needs. Adv Pediatr 2006;53:165-82.Newacheck PW, Strickland B, Shonkoff JP, et al. An epidemiologic profile of children with special health care needs. Pediatrics 1998;102:117-23.Stein REK, Silver EJ. Operationalizing a conceptually based noncategorical definition. A first look at U.S. children with chronic conditions. Arch Pediatr Adolesc Med 1999;153:68-74.Child and Adolescent Health Measurement Initiative. The children with special health care needs (CSHCN) screener. Baltimore: CAHMI; 1998. 10p.Child and adolescent initiative. Who are children with special health care needs (CSHCN). Baltimore: CAHMI; 2012. 2p.Bethell CD, Read D, Neff J, et al. Comparison of the children with special health care needs screener to the questionnaire for identifying children with chronic conditions–revised. Ambul Pediatr 2002;2:49-57.Read D, Bethell C, Blumberg SJ, et al. An evaluation of the linguistic and cultural validity of the Spanish language version of the children with special health care needs screener. Matern Child Health J 2007;11(6):568-85.Kennedy P, editor. The Oxford Handbook of Rehabilitation Psychology. Oxford, New York: Oxford University Press; 2012.