Corrigendum: Rotavirus-Mediated Prostaglandin E2 Production in MA104 Cells Promote Virus Attachment and Internalisation, Resulting in an Increased Viral Load.

[This corrects the article DOI: 10.3389/fphys.2022.805565.].

Rotavirus-Mediated Prostaglandin E2 Production in MA104 Cells Promotes Virus Attachment and Internalisation, Resulting in an Increased Viral Load.

Rotaviruses are one of the leading causes of severe dehydrating diarrhoea in infants and children under the age of five. Despite the introduction of vaccines, disease burden remains high in sub-Saharan Africa, with no known anti-viral treatments available. During early infection rotavirus attaches to several cellular receptors and enters the cells by either clathrin-dependent or -independent endocytosis. Prostaglandin E2, an abundant eicosanoid, is produced from arachidonic acid during rotavirus infection and inhibition of prostaglandin E2 formation have a deleterious effect on rotavirus infection. In this study, MA104 cells were supplemented with γ-linolenic acid (GLA), a precursor of arachidonic acid. Infection of supplemented cells with rotavirus SA11 led to a depletion in the relative percentages of GLA and arachidonic acid which coincided with an increased production of prostaglandin E2 as monitored by ELISA. Confocal microscopy demonstrated that prostaglandin E2 co-localises with the viroplasm-forming proteins, NSP5 and NSP2. Due to the known association of viroplasms with lipid droplets and the fact that lipid droplets are sites for prostaglandin E2 production, our results indicate a possible role for viroplasms in the production of rotavirus-induced prostaglandin E2. Replication kinetics showed that inhibitors, targeting the biosynthesis of prostaglandin E2, had negative effects on rotavirus yield, especially during the early stages of infection. Using flow cytometry and prostaglandin E2 addback experiments, we show that prostaglandin E2 enhances the attachment and internalisation of rotavirus in MA104 cells indicating a possible role for prostaglandin E2 during clathrin-mediated rotavirus entry. The production of prostaglandin E2 during rotavirus infection could serve as a possible target for anti-viral treatment.

Milk composition of white rhinoceros over lactation and comparison with other Perissodactyla.

The proximate composition of milk from fifteen free-ranging white rhinoceroses at different lactation stages is reported with detailed analysis of fatty acid composition and minerals. Lactose is the main component at 7.93 ± 0.53%, followed by 0.93 ± 0.19% protein, 1.76 ± 0.39% fat, 0.40 ± 0.18% ash, 0.05 ± 0.01% glucose, and 0.04 ± 0.02% non protein nitrogen The interindividual variation of all the components is high, showing no trend of change over lactation. The K and P content decreased over lactation. The fatty acid composition of rhinoceros milk is characteristic with a high saturated fatty acids content of 62%-84%, of which the medium chain fatty acids form the major portion. The C10:0, C12:0, C16:0, and C18:1c9 are the major fatty acids in the milk fat. The results are compared with the two other Perissodactylae families, the Equidae and Tapiridae. Differences in gross composition are small, but the milk of the Rhinocerotidae have the lowest gross energy, while the milk fats consist of the highest amounts of saturated fatty acids, while the low levels of C16:1c9 and C18:1c9 indicate the lowest mammary Δ9-desaturase activity.

Milk Composition of Free-Ranging Impala (Aepyceros melampus) and Tsessebe (Damaliscus lunatus lunatus), and Comparison with Other African Bovidae.

The major nutrient and fatty acid composition of the milk of impala and tsessebe is reported and compared with other Bovidae and species. The proximate composition of impala milk was 5.56 ± 1.96% fat, 6.60 ± 0.51% protein, and 4.36 ± 0.94% lactose, and that of tsessebe milk was 8.44 ± 3.19%, 5.15 ± 0.49%, and 6.10 ± 3.85%, respectively. The high protein content of impala milk accounted for 42% of gross energy, which is typical for African Bovids that use a "hider" postnatal care system, compared to the 25% of the tsessebe, a "follower". Electrophoresis showed that the molecular size and surface charge of the tsessebe caseins resembled that of other Alcelaphinae members, while that of the impala resembled that of Hippotraginae. The milk composition of these two species was compared by statistical methods with 13 other species representing eight suborders, families, or subfamilies of African Artiodactyla. This showed that the tsessebe milk resembled that of four other species of the Alcelaphinae sub-family and that the milk of this sub-family differs from other Artiodactyla by its specific margins of nutrient contents and milk fat with a high content of medium-length fatty acids (C8-C12) above 17% of the total fatty acids.

Relationship between weather conditions and the physicochemical characteristics of cladodes and mucilage from two cactus pear species.

Climate change, limited water resources and expected population increases would require crops which contribute toward more resilient, more productive, more sustainable and climate-smart food systems. The cactus pear is a drought-resistant and sustainable food source to humans and livestock alike. Cactus mucilage has multiple applications in the food and packaging industry. It is eco-friendly, economical, functional and has multiple health benefits. However, the researchers observed umpteen variations in extracted mucilage yield and viscosity every time the cladodes were harvested, making the standardisation of formulations troublesome. We aimed to examine the effect of weather conditions on the physicochemical characteristics of cactus pear cladodes and mucilage extracted over two seasons to understand these observed variations in mucilage characteristics. Forty cladodes, ten from each of Opuntia ficus-indica Algerian, Morado and Gymno-Carpo and Opuntia robusta Robusta were harvested every month from February to August in Bloemfontein, South Africa. Daily weather data were obtained, weight and moisture contents determined on cladodes and yield, viscosity, pH, conductivity and malic acid content determined on extracted mucilage. Pearson correlation coefficients were calculated between the weather conditions, cladode properties, and mucilage properties. Contrary to common belief, neither increasing cladode weight as they grow, nor rainfall were the leading causes of mucilage inconsistencies. However, the correlations showed a relationship between environmental temperatures, cladode pH and conductivity, and mucilage viscosity and yields. In hot summer weather, the pH was lower, which led to an abundance of positive ions in cladodes. The H+ ions neutralise the negative charges along the outstretched mucilage molecule, causing it to coil up, reducing the viscosity of the mucilage. Thus, environmental temperatures rather than rainfall or cladode maturity influenced the physicochemical characteristics of mucilage. The findings should make an essential contribution in predicting the physicochemical characteristics of mucilage for specific food-related functions by observing the weather conditions.

The Dynamic Changes of African Elephant Milk Composition over Lactation.

The combined data of milk composition of 14 African elephants over 25 months of lactation are presented. The milk density was constant during lactation. The total protein content increased with progressing lactation, with caseins as the predominant protein fraction. The total carbohydrates steadily decreased, with the oligosaccharides becoming the major fraction. Lactose and isoglobotriose reached equal levels at mid lactation. The milk fat content increased during lactation, as did the caprylic and capric acids, while the 12 carbon and longer fatty acids decreased. The fatty acid composition of the milk phospholipids fluctuated, and their total saturated fatty acid composition was low compared to the triacylglycerides. The milk ash and content of the major minerals, Na, K, Mg, P, and Ca, increased. Vitamin content was low, Vitamin E occurred in quantifiable amounts, with traces of vitamins A, D3, and K. The energy levels of African elephant milk did not change much in the first ten months of lactation, but they increased thereafter due to the increase in protein and fat content. The overall changes in milk composition appeared to be in two stages: (a) strong changes up to approximately 12 months of lactation and (b) little or no changes thereafter.

Hedonic evaluation and check-all-that-apply (CATA) question for sensory characterisation of stewed vegetable Amaranthus.

Hedonic assessment and sensory characteristics of 13 Amaranthus genotypes, stewed with onions, tomatoes and potatoes, were evaluated. 50 consumers ranked their preference on a nine-point hedonic scale to determine overall acceptability of the stewed samples. In addition, 100 consumers were asked to select sensory characteristics that described the genotypes best, using the Check-all-that-apply question. Hedonic responses indicated significant differences (p < 0.001) between stewed samples. Significant differences were also found in the frequency with which consumers used 15 of the 23 terms generated to characterise the sensory profile of stewed Amaranthus leaves. Correspondence analysis illustrated differences in sensory characteristics between genotypes, describing 72.4% variance. Agglomerative hierarchical clustering indicated three consumer preference clusters, while external preference mapping showed the regions of maximum liking. There was no correlation between hedonic evaluation and sensory characteristics. In addition, no strong association between specific species, genotypes and sensory attributes was observed.

Differences in Health-related Fatty Acids, Intramuscular Fat and the Physico-chemical Quality in Mutton as Affected by Season, Place of Purchase and Meat Portion.

The objective of the study was to determine the quality and fatty acid profiles of mutton cuts purchased from rural and urban localities in South Africa. Five hundred and ten samples were collected in four seasons from both rural and urban shops and butcheries. Samples were immediately transported to the laboratory in cooler boxes with ice where the following physico-chemical characteristics of mutton were determined; meat pH, color (L*, a*, and b*), cooking losses and Warner Braztler shear force and replicates stored at -20°C pending fatty acid analysis. Meat L* values were lowest (24.7±0.49) in winter and highest (32.2±0.49) in spring. The loin and sirloin cuts recorded the highest intramuscular fat whilst rib and leg cuts recorded the lowest intramuscular fat. In conclusion intramuscular fat, fatty acid profiles and physico-chemical quality of mutton were significantly affected by season and meat portion and not necessarily by the locality and class of shop.