Effects of a Cyanobacterial Toxin and Macrophyte composition on Amphibian Parasitism

Low Concentrations ◽

Host Growth ◽

Host Parasite ◽

Amphibians are experiencing global declines with habitat loss and degradation, and infectious diseases as major contributors. Environmental changes such as eutrophication and climate alterations can cause the proliferation of primary producers, including cyanobacteria, and both native and invasive macrophytes. Cyanobacterial blooms can be toxic due to the production of microcystins such as MC-LR, and invasive macrophytes can alter the structural complexity of aquatic habitats – both can affect host-parasite dynamics. I examined the effects of MC-LR on larval amphibian susceptibility to infection by a trematode parasite as well as host growth and anti-parasite behaviour, finding increased susceptibility to infection at low concentrations. I also investigated how MC-LR affected the longevity and activity of trematode infectious stages (cercariae), and demonstrated variable effects among species. Lastly, I examined how environmental structural complexity, modeled as macrophyte complexity and density, affected tadpole infection by a trematode parasite and host anti-parasite behaviour but found no impact.

Effects of a Cyanobacterial Toxin and Macrophyte composition on Amphibian Parasitism

10.32920/ryerson.14651589 ◽

2021 ◽

Author(s):

Marin Milotic

Keyword(s):

Environmental Changes ◽

Structural Complexity ◽

Cyanobacterial Blooms ◽

Trematode Parasite ◽

Cyanobacterial Toxin ◽

Low Concentrations ◽

Host Growth ◽

Host Parasite ◽

Cyanobacteria and Cyanotoxins in a Changing Environment: Concepts, Controversies, Challenges

Water ◽

10.3390/w13182463 ◽

2021 ◽

Vol 13 (18) ◽

pp. 2463

Author(s):

Ingrid Chorus ◽

Jutta Fastner ◽

Martin Welker

Keyword(s):

Climate Change ◽

Health Risks ◽

Environmental Changes ◽

Research Field ◽

Cyanobacterial Blooms ◽

Toxic Cyanobacteria ◽

Low Concentrations ◽

Guideline Values ◽

Wide Range ◽

The Absolute

Concern is widely being published that the occurrence of toxic cyanobacteria is increasing in consequence of climate change and eutrophication, substantially threatening human health. Here, we review evidence and pertinent publications to explore in which types of waterbodies climate change is likely to exacerbate cyanobacterial blooms; whether controlling blooms and toxin concentrations requires a balanced approach of reducing not only the concentrations of phosphorus (P) but also those of nitrogen (N); how trophic and climatic changes affect health risks caused by toxic cyanobacteria. We propose the following for further discussion: (i) Climate change is likely to promote blooms in some waterbodies—not in those with low concentrations of P or N stringently limiting biomass, and more so in shallow than in stratified waterbodies. Particularly in the latter, it can work both ways—rendering conditions for cyanobacterial proliferation more favourable or less favourable. (ii) While N emissions to the environment need to be reduced for a number of reasons, controlling blooms can definitely be successful by reducing only P, provided concentrations of P can be brought down to levels sufficiently low to stringently limit biomass. Not the N:P ratio, but the absolute concentration of the limiting nutrient determines the maximum possible biomass of phytoplankton and thus of cyanobacteria. The absolute concentrations of N or P show which of the two nutrients is currently limiting biomass. N can be the nutrient of choice to reduce if achieving sufficiently low concentrations has chances of success. (iii) Where trophic and climate change cause longer, stronger and more frequent blooms, they increase risks of exposure, and health risks depend on the amount by which concentrations exceed those of current WHO cyanotoxin guideline values for the respective exposure situation. Where trophic change reduces phytoplankton biomass in the epilimnion, thus increasing transparency, cyanobacterial species composition may shift to those that reside on benthic surfaces or in the metalimnion, changing risks of exposure. We conclude that studying how environmental changes affect the genotype composition of cyanobacterial populations is a relatively new and exciting research field, holding promises for understanding the biological function of the wide range of metabolites found in cyanobacteria, of which only a small fraction is toxic to humans. Overall, management needs case-by-case assessments focusing on the impacts of environmental change on the respective waterbody, rather than generalisations.

LONG-COURSE ORAL CORTICOSTEROID TOXICITY IN CHILDREN

Archives of Disease in Childhood ◽

10.1136/archdischild-2016-311535.57 ◽

2016 ◽

Vol 101 (9) ◽

pp. e2.53-e2 ◽

Cited By ~ 1

Author(s):

Fahad Aljebab ◽

Imti Choonara ◽

Sharon Conroy

Keyword(s):

Weight Gain ◽

Growth Retardation ◽

Oral Prednisolone ◽

Incidence Rates ◽

Cochrane Library ◽

Varicella Zoster ◽

Oral Corticosteroids ◽

Long Course ◽

BackgroundLong courses of oral corticosteroids are commonly used in children in the management of conditions such as nephrotic syndrome, leukaemia, asthma and others. Various adverse drug reactions (ADRs) are known to occur with their use. This systematic review aimed to identify the most common and serious ADRs and to determine their relative risk levels.MethodsA literature search of several databases; Embase, Medline, International Pharmaceutical Abstracts, CINAHL, the Cochrane Library and PubMed was performed to identify all studies where corticosteroids had been administered to paediatric patients ranging from 28 days to 18 years of age for at least 15 days of treatment. Each database was searched from their earliest dates to March 2014. All types of studies that provided clear information on ADRs were included.Results91 relevant studies were found from 27 countries. These studies represented a total of 6653 children and contained reports of 4124 ADRs, the majority in patients with leukaemia, haemangioma and asthma. Oral prednisolone was the most commonly prescribed corticosteroid (74% of patients). The three most frequent ADRs were weight gain, Cushingoid features and growth retardation. The incidence rates of patients with these three ADRs were 22.4%, 20.6% and 18.9%, respectively. Increased susceptibility to infection was the most serious ADR. 24 children died from infections, ten from varicella zoster and the others from different microorganisms.ConclusionsWeight gain, Cushingoid features and growth retardation were the most frequent ADRs seen when long-course oral corticosteroids were given to children. In addition, increased susceptibility to infection was the most common cause of mortality.

Harmful phytoplankton blooms and fish mortality in a eutrophicated reservoir of northeast Brazil

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132008000400022 ◽

2008 ◽

Vol 51 (4) ◽

pp. 633-641 ◽

Cited By ~ 23

Author(s):

Naithirithi Tiruvenkatachary Chellappa ◽

Sarah Laxhmi Chellappa ◽

Sathyabama Chellappa

Keyword(s):

Cyanobacterial Bloom ◽

Hplc Method ◽

Freshwater Ecosystems ◽

Cyanobacterial Blooms ◽

Fish Mortality ◽

Cylindrospermopsis Raciborskii ◽

Northeast Brazil ◽

Cyanobacterial Toxin ◽

Bloom Formation ◽

Harmful Effects

The aim of this work was to study the eutrophication in the tropical freshwater ecosystems and the consequent cyanobacterial bloom formation and economical damage to fisheries and harmful effects to public health. Mass fish mortality due to toxin producing cyanobacterial blooms was registered during December 2003 in Marechal Dutra Reservoir, Acari/RN, Northeast Brazil. Phytoplankton and fish samplings were carried out on alternate days during the episode of fish mortality and monthly during January to June 2004. The cyanobacterial toxin was identified and quantified from the seston samples and liver of the dead fishes using the standard HPLC method. The results indicated that the toxic blooms of Cylindrospermopsis raciborskii and Microcystis aeruginosa were persistent for two weeks and represented 90% of the phytoplankton species assemblages. The lethally affected fishes were Oreochromis niloticus, Plagioscion squamosissimus, Cichla monoculus, Prochilodus brevis, Hoplias malabaricus and Leporinus friderici. The microcystin levels varied from 0.07 to 8.73µg L-1 the seston samples and from 0.01 to 2.59µg g-1in the liver samples of the fishes during the bloom period.

Defect in neutrophil killing and increased susceptibility to infection with nonpathogenic gram-positive bacteria in peptidoglycan recognition protein-S (PGRP-S)–deficient mice

Blood ◽

10.1182/blood-2002-12-3853 ◽

2003 ◽

Vol 102 (2) ◽

pp. 689-697 ◽

Cited By ~ 128

Author(s):

Roman Dziarski ◽

Kenneth A. Platt ◽

Eva Gelius ◽

Håkan Steiner ◽

Dipika Gupta

Keyword(s):

Inflammatory Responses ◽

Protein S ◽

Intracellular Killing ◽

Gram Positive ◽

Peptidoglycan Recognition Protein ◽

Gram Positive Bacteria ◽

Recognition Protein ◽

Factor Α ◽

AbstractInsect peptidoglycan recognition protein-S (PGRP-S), a member of a family of innate immunity pattern recognition molecules conserved from insects to mammals, recognizes bacterial cell wall peptidoglycan and activates 2 antimicrobial defense systems, prophenoloxidase cascade and antimicrobial peptides through Toll receptor. We show that mouse PGRP-S is present in neutrophil tertiary granules and that PGRP-S–deficient (PGRP-S-/-) mice have increased susceptibility to intraperitoneal infection with gram-positive bacteria of low pathogenicity but not with more pathogenic gram-positive or gram-negative bacteria. PGRP-S-/- mice have normal inflammatory responses and production of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6). Neutrophils from PGRP-S-/- mice have normal phagocytic uptake of bacteria but are defective in intracellular killing and digestion of relatively nonpathogenic gram-positive bacteria. Therefore, mammalian PGRP-S functions in intracellular killing of bacteria. Thus, only bacterial recognition by PGRP-S, but not its effector function, is conserved from insects to mammals.

Nutrition and Covid-19 epidemic

Acta agriculturae Slovenica ◽

10.14720/aas.2021.117.2.1980 ◽

2021 ◽

Vol 117 (2) ◽

pp. 1

Author(s):

Tanja PAJK ŽONTAR ◽

Rajko VIDRIH

Keyword(s):

Physical Activity ◽

Immune System ◽

Immune Function ◽

Omega 3 ◽

Healthy Foods ◽

Iron And Zinc ◽

Dietary Nutrient ◽

Current Context ◽

Proper nutrition is an essential part of an individual’s defence against numerous diseases including coronavirus disease SARS-CoV-2 (Covid-19). Nutritional status of individual is affected by several factors such as age, sex, health status, physical activity, life style and medications. Optimal nutrition and dietary nutrient intake impact the immune system, therefore the sustainable way to survive in current context is to strengthen the immune system. Inadequate intake of energy, protein, and specific micronutrients are associated with depressed immune function and increased susceptibility to infection. Predominantly vital for the encouraging of immune function are elements selenium, iron and zinc and vitamins A, D, C, E, B6, B9 (folate) and B12 as well as omega-3 polyunsaturated fatty acids. Thus, during this time it is important to take care of nutritional habits, following a healthy and balanced nutritional pattern containing a high amount of elements, antioxidants and vitamins. It is also recommended, that individuals should be mindful of physical activity, known to be associated with all-cause mortality. Regular physical activity also improves mental health and overall feelings of wellbeing. Thus, now in the time of epidemic, more than ever, wider access to healthy foods should be a top priority for governments around the world

Chediak-Higashi syndrome: reversal of increased susceptibility to infection by bone marrow transplantation

Blood ◽

10.1182/blood.v47.4.555.bloodjournal474555 ◽

1976 ◽

Vol 47 (4) ◽

pp. 555-559

Author(s):

JA Kazmierowski ◽

RJ Elin ◽

HY Reynolds ◽

WA Durbin ◽

SM Wolff

Keyword(s):

Bone Marrow ◽

Candida Albicans ◽

Bone Marrow Transplantation ◽

Human Disease ◽

Marrow Transplantation ◽

Normal Bone Marrow ◽

Normal Bone ◽

Chediak Higashi Syndrome ◽

Transplantation of normal bone marrow to mice with the Chediak-Higashi syndrome (CHS) resulted in normal granulopoiesis and a reversal of their increased susceptibility to challenge with intravenous Candida albicans. These findings suggest that (1) the leukocyte defect in CHS can be reversed by marrow transplantation and (2) the mechanism for increased susceptibility to infection in these animals is due to a bone- marrow-derived cellular defect. Because of similarities between murine and human CHS, bone marrow transplantation might be considered as a mode of therapy in selected cases of the human disease.

Resilience of Microbial Communities after Hydrogen Peroxide Treatment of a Eutrophic Lake to Suppress Harmful Cyanobacterial Blooms

Microorganisms ◽

10.3390/microorganisms9071495 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1495

Author(s):

Tim Piel ◽

Giovanni Sandrini ◽

Gerard Muyzer ◽

Corina P. D. Brussaard ◽

Pieter C. Slot ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Microbial Community ◽

Microbial Communities ◽

Microbial Community Composition ◽

Glycoside Hydrolases ◽

Microbial Community Analysis ◽

Cyanobacterial Blooms ◽

Temporary Increase ◽

Low Concentrations ◽

Harmful Cyanobacterial Blooms

Applying low concentrations of hydrogen peroxide (H2O2) to lakes is an emerging method to mitigate harmful cyanobacterial blooms. While cyanobacteria are very sensitive to H2O2, little is known about the impacts of these H2O2 treatments on other members of the microbial community. In this study, we investigated changes in microbial community composition during two lake treatments with low H2O2 concentrations (target: 2.5 mg L−1) and in two series of controlled lake incubations. The results show that the H2O2 treatments effectively suppressed the dominant cyanobacteria Aphanizomenon klebahnii, Dolichospermum sp. and, to a lesser extent, Planktothrix agardhii. Microbial community analysis revealed that several Proteobacteria (e.g., Alteromonadales, Pseudomonadales, Rhodobacterales) profited from the treatments, whereas some bacterial taxa declined (e.g., Verrucomicrobia). In particular, the taxa known to be resistant to oxidative stress (e.g., Rheinheimera) strongly increased in relative abundance during the first 24 h after H2O2 addition, but subsequently declined again. Alpha and beta diversity showed a temporary decline but recovered within a few days, demonstrating resilience of the microbial community. The predicted functionality of the microbial community revealed a temporary increase of anti-ROS defenses and glycoside hydrolases but otherwise remained stable throughout the treatments. We conclude that the use of low concentrations of H2O2 to suppress cyanobacterial blooms provides a short-term pulse disturbance but is not detrimental to lake microbial communities and their ecosystem functioning.

Cyanobacterial Toxin Degrading Bacteria: Who Are They?

BioMed Research International ◽

10.1155/2013/463894 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 40

Author(s):

Konstantinos Ar. Kormas ◽

Despoina S. Lymperopoulou

Keyword(s):

Meta Analysis ◽

Toxin Production ◽

Cyanobacterial Blooms ◽

Ecological Knowledge ◽

Cyanobacterial Toxin ◽

Molecular Approaches ◽

Degrading Bacteria ◽

Ecological Problems ◽

Ecosystem Level ◽

Toxin Degradation

Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA andmlrA(microcystinase) genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of theMethylobacillusandPaucibactergenera. Other strains belonged to the generaArthrobacter, Bacillus, andLactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.

Prevalence of hepatitis B surface antigen and antibody in white and black patients with diabetes mellitus

Journal of Clinical Microbiology ◽

10.1128/jcm.4.6.467-469.1976 ◽

1976 ◽

Vol 4 (6) ◽

pp. 467-469

Author(s):

M C Kew ◽

M E MacKay ◽

A Mindel ◽

B I Joffe ◽

B Kusman ◽

...

Keyword(s):

Diabetes Mellitus ◽

Hepatitis B ◽

Surface Antigen ◽

Hepatitis B Surface Antigen ◽

Impaired Ability ◽

Black Patients ◽

B Virus ◽

Patients With Diabetes ◽

The prevalence of hepatitis B surface antigen (HBSAg) and antibody (anti-HBS) was determined in 531 white and 519 black diabetic outpatients and in appropriate white and black control populations. There was no difference between the prevalence of either HBSAg or anti-HBS in either the white or black diabetics and that in the white and black controls. These findings make it unlikely that the vast majority of patients with diabetes mellitus have either an increased susceptibility to infection by the hepatitis B virus or an impaired ability to clear the virus once they are infected.