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

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

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

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

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 evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

An observational study of road safety around selected primary schools in Ibadan municipality, Oyo State, Southwestern Nigeria

Background/ Objective: Child pedestrians have been identified as vulnerable road users. Although walking as a means of transport has health and other benefits, it exposes children to the risk of road traffic injuries. This study was conducted to assess the availability of road safety features around government-owned primary schools in Ibadan municipality. Materials and Methods: A multistage sampling technique was used to select 46 of the 74 schools in the study area. Some (11) of the selected schools were sited within the same premises and shared a common entrance; thus a total of 35 school premises were eventually observed. Trained research assistants observed the school environment around the selected schools for road safety features such as location of schools, presence of "school", "child crossing" and "speed limit" road signs, and presence of traffic calming devices (road bumps or zebra crossing). Results: Five (14%) of the schools were located on major roads and eight (23%) had road signs indicating that a school was nearby. Seven (20%) had road bumps close to the school, 15 (43%) had a warden who assisted children to cross, and none had a zebra crossing. Five (14%) schools had pedestrian sidewalks. Conclusions: The study revealed that the environment around a number of the observed schools in the municipality compromised the pupils′ road safety. The local government, school authorities, parents, and road safety professionals need to institute definite measures to enhance the road safety environment around schools in the municipality

An observational study of road safety around selected primary schools in Ibadan municipality, Oyo State, Southwestern Nigeria

Background/ Objective: Child pedestrians have been identified as vulnerable road users. Although walking as a means of transport has health and other benefits, it exposes children to the risk of road traffic injuries. This study was conducted to assess the availability of road safety features around government-owned primary schools in Ibadan municipality. Materials and Methods: A multistage sampling technique was used to select 46 of the 74 schools in the study area. Some (11) of the selected schools were sited within the same premises and shared a common entrance; thus a total of 35 school premises were eventually observed. Trained research assistants observed the school environment around the selected schools for road safety features such as location of schools, presence of "school", "child crossing" and "speed limit" road signs, and presence of traffic calming devices (road bumps or zebra crossing). Results: Five (14%) of the schools were located on major roads and eight (23%) had road signs indicating that a school was nearby. Seven (20%) had road bumps close to the school, 15 (43%) had a warden who assisted children to cross, and none had a zebra crossing. Five (14%) schools had pedestrian sidewalks. Conclusions: The study revealed that the environment around a number of the observed schools in the municipality compromised the pupils′ road safety. The local government, school authorities, parents, and road safety professionals need to institute definite measures to enhance the road safety environment around schools in the municipality

An observational study of road safety around selected primary schools in Ibadan municipality, Oyo State, Southwestern Nigeria

Background/ Objective: Child pedestrians have been identified as vulnerable road users. Although walking as a means of transport has health and other benefits, it exposes children to the risk of road traffic injuries. This study was conducted to assess the availability of road safety features around government-owned primary schools in Ibadan municipality. Materials and Methods: A multistage sampling technique was used to select 46 of the 74 schools in the study area. Some (11) of the selected schools were sited within the same premises and shared a common entrance; thus a total of 35 school premises were eventually observed. Trained research assistants observed the school environment around the selected schools for road safety features such as location of schools, presence of "school", "child crossing" and "speed limit" road signs, and presence of traffic calming devices (road bumps or zebra crossing). Results: Five (14%) of the schools were located on major roads and eight (23%) had road signs indicating that a school was nearby. Seven (20%) had road bumps close to the school, 15 (43%) had a warden who assisted children to cross, and none had a zebra crossing. Five (14%) schools had pedestrian sidewalks. Conclusions: The study revealed that the environment around a number of the observed schools in the municipality compromised the pupils\u2032 road safety. The local government, school authorities, parents, and road safety professionals need to institute definite measures to enhance the road safety environment around schools in the municipality