27 research outputs found
Henipavirus Neutralising Antibodies in an Isolated Island Population of African Fruit Bats
Isolated islands provide valuable opportunities to study the persistence of viruses in wildlife populations, including population size thresholds such as the critical community size. The straw-coloured fruit bat, Eidolon helvum, has been identified as a reservoir for henipaviruses (serological evidence) and Lagos bat virus (LBV; virus isolation and serological evidence) in continental Africa. Here, we sampled from a remote population of E. helvum annobonensis fruit bats on Annobón island in the Gulf of Guinea to investigate whether antibodies to these viruses also exist in this isolated subspecies. Henipavirus serological analyses (Luminex multiplexed binding and inhibition assays, virus neutralisation tests and western blots) and lyssavirus serological analyses (LBV: modified Fluorescent Antibody Virus Neutralisation test, LBV and Mokola virus: lentivirus pseudovirus neutralisation assay) were undertaken on 73 and 70 samples respectively. Given the isolation of fruit bats on Annobón and their lack of connectivity with other populations, it was expected that the population size on the island would be too small to allow persistence of viruses that are thought to cause acute and immunising infections. However, the presence of antibodies against henipaviruses was detected using the Luminex binding assay and confirmed using alternative assays. Neutralising antibodies to LBV were detected in one bat using both assays. We demonstrate clear evidence for exposure of multiple individuals to henipaviruses in this remote population of E. helvum annobonensis fruit bats on Annobón island. The situation is less clear for LBV. Seroprevalences to henipaviruses and LBV in Annobón are notably different to those in E. helvum in continental locations studied using the same sampling techniques and assays. Whilst cross-sectional serological studies in wildlife populations cannot provide details on viral dynamics within populations, valuable information on the presence or absence of viruses may be obtained and utilised for informing future studies
Next Generation Nanochitosan Applications in Animal Husbandry, Aquaculture and Food Conservation
Studies have identified the properties of enzymes, functionalized
molecules, and compounds in food industry applications as edible
coatings and encapsulations, that assure prolonged food quality and
standards. These molecules present benefits of longer shelf-life by
delayed deterioration and inhibition of the proliferation of spoilage and
mycotoxigenic microorganisms. However, challenges of reduced
nutrient levels, miniaturized size, and low chemical stability remain
concerning. Chitosan polymers naturally formed from the
deacetylation of shellfish shells and exoskeletons of aquatic
arthropods and crustaceans offer improved benefits when
functionalized into nanoparticles as nanochitosans. These
polysaccharides produced by the alkalescent deacetylation of chitin,
comprise a series of 2-deoxy-2 (acetylamino) glucose linked by ß-(1-
4) glycosidic linkages. This chapter considers the health impacts and
microbiological health hazards associated with animal feeds quality
and the enzyme immobilization potentials of nanochitosans in animalbased
food and feed packages. Thereafter, nanochitosan properties
and benefits are compared against traditional preservatives from
microbes and plants; with highlights on current challenges in the
application of nanochitosan for enzyme immobilization
Utilization of nanochitosan for enzyme immobilization of aquatic and animal-based food packages
Studies have identified the properties of enzymes, functionalized molecules, and compounds in food industry applications as edible coatings and encapsulations, that assure prolonged food quality and standards. These molecules present benefits of longer shelf-life by delayed deterioration and inhibition of the proliferation of spoilage and mycotoxigenic microorganisms. However, challenges of reduced nutrient levels, miniaturized size, and low chemical stability remain concerning. Chitosan polymers naturally formed from the deacetylation of shellfish shells and exoskeletons of aquatic arthropods and crustaceans offer improved benefits when functionalized into nanoparticles as nanochitosans. These polysaccharides produced by the alkalescent deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino) glucose linked by ß-(1-4) glycosidic linkages. This chapter considers the health impacts and
Utilization of nanochitosan in the sterilization of ponds and water treatment for aquaculture
Water pollution constitutes the leading cause of infant mortality,
neonatal deformities, and shrinkage of man’s average life expectancy.
Pollutants come from point and nonpoint sources; and water pollution
arises from the discharge of wastewater containing undesirable
impurities used for domestic, agricultural, and industrial purposes.
More so, high nutrient and wastewater runoffs from fish production
systems contribute to the fouling and eutrophication of recipient water
bodies. Hence, aquaculture which is inextricably linked to the natural
environment is challenged by the dearth of appropriate water quantity
and quality, militating against fish, and fishery production.
Nanochitosans as polysaccharides produced by the alkalescent
deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino)
glucose linked by ß-(1-4) glycosidic linkages. They are naturally
formed from the deacetylation of shellfish shells and exoskeletons of
aquatic arthropods and crustaceans. The unique attributes of chitin
confer a wide range of biotechnological applications on the polymer,
observed in flocculation as a wastewater treatment and purification
route initiated by chitosan. This chapter highlights nanochitosan
properties of aquaculture relevance; and elucidates the purification
potentials of nanochitosan, compared to inorganic coagulants and
organic polymeric flocculants. Effects of chitosan on contaminants and
microorganisms, as well as applications in fish pathogens detection,
fish disease diagnosis, and control are discussed
Nanochitosan derived from marine bacteria
Nanochitosans are polysaccharides produced by the alkalescent deacetylation of chitin and comprise
a series of 2‐deoxy‐2 (acetylamino) glucose linked by ß‐(1‐4) glycosidic linkages. These are naturally
formed from the deacetylation of shellfish shells and the exoskeleton of aquatic arthropods and
crustaceans. Reports of chitosan production from unicellular marine bacteria inhabiting the sea, and
possessing distinct animal‐ and plant‐like characteristics abound. This capacity to synthesize chitosan
from chitin arises from response to stress under extreme environmental conditions, as a means of
survival. Consequently, the microencapsulation of these nanocarriers results in new and improved
chitosan nanoparticles, nanochitosan. This nontoxic bioactive material which can serve as an
antibacterial agent, gene delivery vector as well as carrier for protein and drug release as compared
with chitosan, is limited by its nonspecific molecular weight and higher composition of deacetylated
chitin. This chapter highlights the biology and diversity of nanochitosan‐producing marine bacteria,
including the factors influencing their activities, survival, and distribution. More so, the applications
of marine bacterial nanochitosans in transfection and gene delivery; wound healing and drug
delivery; feed supplement development and antimicrobial activity are discussed
Chapter 21 - Utilization of nanochitosan in the sterilization of ponds and water treatment for aquaculture
Water pollution constitutes the leading cause of infant mortality,
neonatal deformities, and shrinkage of man’s average life expectancy.
Pollutants come from point and nonpoint sources; and water pollution
arises from the discharge of wastewater containing undesirable
impurities used for domestic, agricultural, and industrial purposes.
More so, high nutrient and wastewater runoffs from fish production
systems contribute to the fouling and eutrophication of recipient water
bodies. Hence, aquaculture which is inextricably linked to the natural
environment is challenged by the dearth of appropriate water quantity
and quality, militating against fish, and fishery production.
Nanochitosans as polysaccharides produced by the alkalescent
deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino)
glucose linked by ß-(1-4) glycosidic linkages. They are naturally
formed from the deacetylation of shellfish shells and exoskeletons of
aquatic arthropods and crustaceans. The unique attributes of chitin
confer a wide range of biotechnological applications on the polymer,
observed in flocculation as a wastewater treatment and purification
route initiated by chitosan. This chapter highlights nanochitosan properties of aquaculture relevance; and elucidates the purification
potentials of nanochitosan, compared to inorganic coagulants and
organic polymeric flocculants. Effects of chitosan on contaminants and
microorganisms, as well as applications in fish pathogens detection,
fish disease diagnosis, and control are discussed
The Pathopharmacological Interplay between Vanadium and Iron in Parkinson’s Disease Models
Parkinson’s disease (PD) pathology is characterised by distinct types of cellular defects, notably associated with oxidative damage and mitochondria dysfunction, leading to the selective loss of dopaminergic neurons in the brain’s substantia nigra pars compacta (SNpc). Exposure to some environmental toxicants and heavy metals has been associated with PD pathogenesis. Raised iron levels have also been consistently observed in the nigrostriatal pathway of PD cases. This study explored, for the first time, the effects of an exogenous environmental heavy metal (vanadium) and its interaction with iron, focusing on the subtoxic effects of these metals on PD-like oxidative stress phenotypes in Catecholaminergic a-differentiated (CAD) cells and PTEN-induced kinase 1 (PINK−1)B9Drosophila melanogaster models of PD. We found that undifferentiated CAD cells were more susceptible to vanadium exposure than differentiated cells, and this susceptibility was modulated by iron. In PINK−1 flies, the exposure to chronic low doses of vanadium exacerbated the existing motor deficits, reduced survival, and increased the production of reactive oxygen species (ROS). Both Aloysia citrodora Paláu, a natural iron chelator, and Deferoxamine Mesylate (DFO), a synthetic iron chelator, significantly protected against the PD-like phenotypes in both models. These results favour the case for iron-chelation therapy as a viable option for the symptomatic treatment of PD