Gastrointestinal Infection in South African Children under the Age of 5 years: A Mini Review.

Objective: To estimate gastroenteritis disease and its etiological agents in children under the age of 5 years living in South Africa. Methods: A mini literature review of pertinent articles published in ScienceDirect, PubMed, GoogleScholar, and Scopus was conducted using search terms: "Gastroenteritis in children," "Gastroenteritis in the world," Gastroenteritis in South Africa," "Prevalence of gastroenteritis," "Epidemiological surveillance of gastroenteritis in the world," and "Causes of gastroenteritis". Results: A total of 174 published articles were included in this mini review. In the last 20 years, the mortality rate resulting from diarrhea in children under the age of 5 years has declined and this is influenced by improved hygiene practices, awareness programs, an improved water and sanitation supply, and the availability of vaccines. More modern genomic amplification techniques were used to re-analyze stool specimens collected from children in eight low-resource settings in Asia, South America, and Africa reported improved sensitivity of pathogen detection to about 65%, that viruses were the main etiological agents in patients with diarrhea aged from 0 to 11 months but that Shigella, followed by sapovirus and enterotoxigenic Escherichia coli had a high incidence in children aged 12-24 months. In addition, co-infections were noted in nearly 10% of diarrhea cases, with rotavirus and Shigella being the main co-infecting agents together with adenovirus, enteropathogenic E. coli, Clostridium jejuni, or Clostridium coli. Conclusions: This mini review outlines the epidemiology and trends relating to parasitic, viral, and bacterial agents responsible for gastroenteritis in children in South Africa. An increase in sequence-independent diagnostic approaches will improve the identification of pathogens to resolve undiagnosed cases of gastroenteritis. Emerging state and national surveillance systems should focus on improving the identification of gastrointestinal pathogens in children and the development of further vaccines against gastrointestinal pathogens.

A simplified method for the quantitation of short-chain fatty acids in human stool.

A one-vial extraction method for the quantitation of short-chain fatty acids (SCFAs) in human stool was developed. Samples were extracted with an acidified aqueous internal standard solution, sodium sulfate, and diethyl ether, followed by analysis with GC-FID. Accuracy, in terms of relative recovery, was typically between 90 and 110% for most analytes; without internal standard, the accuracy was about 5-34%; the linear dynamic range (LDR) was 0.05-50 µmol per gram; the limit of detection (LOD) was less than or equal to 0.05 µmol per gram; and the (lower) limit of quantitation (LOQ) was 1 µmol per gram. The method is suitable for quantitating acetic acid, propanoic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isohexanoic acid, hexanoic acid, and heptanoic acid. It is not suitable for the quantitation of formic acid. Application to human biological research was tested by the measurement of SCFA in heathy humans. This confirmed that the method performed adequately, and even better than expected, with values up to 150 µmol per gram.

Diet and the Human Gut Microbiome: An International Review.

This review summarizes the key results of recently published studies on the effects of dietary change and nutritional intervention on the human microbiome from around the world, focusing on the USA, Canada, Europe, Asia, and Africa. It first explores mechanisms that might explain the ability of fiber-rich foods to suppress the incidence and mortality from westernized diseases, notably cancers of the colon, breast, liver, cardiovascular, infectious, and respiratory diseases, diabetes, and obesity (O'Keefe in Lancet Gastroenterol Hepatol 4(12):984-996, 2019; Am J Clin Nutr 110:265-266, 2019). It summarizes studies from Africa which suggest that disturbance of the colonic microbiome may exacerbate chronic malnutrition and growth failure in impoverished communities and highlights the importance of breast feeding. The American section discusses the role of the microbiome in the swelling population of patients with obesity and type 2 diabetes and examines the effects of race, ethnicity, geography, and climate on microbial diversity and metabolism. The studies from Europe and Asia extoll the benefits of whole foods and plant-based diets. The Asian studies examine the worrying changes from low-fat, high-carbohydrate diets to high-fat, low-carbohydrate ones and the increasing appearance of westernized diseases as in Africa and documents the ability of high-fiber traditional Chinese diets to reverse type 2 diabetes and control weight loss. In conclusion, most of the studies reviewed demonstrate clear changes in microbe abundances and in the production of fermentation products, such as short-chain fatty acids and phytochemicals following dietary change, but the significance of the microbiota changes to human health, with the possible exception of the stimulation of butyrogenic taxa by fiber-rich foods, is generally implied and not measured. Further studies are needed to determine how these changes in microbiota composition and metabolism can improve our health and be used to prevent and treat disease.

LPS-induces IL-6 and IL-8 gene expression in bovine endometrial cells "through DNA methylation".

Uterine infection in dairy cows causes great economic loss. In bovine endometrial cells, lipopolysaccharide (LPS)-stimulated increase in interleukin 6 (IL-6) and interleukin 8 (IL-8) mRNA is crucial for the inflammatory response; however, the regulatory mechanisms remain unclear. Here, we investigated the role of DNA methylation in IL-6 and IL-8 mRNA expression following LPS-induction in bovine endometrial cells. IL-6 and IL-8 mRNA expression was evaluated under DNA methylation inhibition using 5-Aza-2'-deoxycytodine (5Aza) following LPS stimulation. Expression of DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B), methyl CpG-binding protein 2 (MeCP2) and DNA methylation at IL-6 and IL-8 regions, were analyzed using quantitative real-time PCR (qRT-PCR) and bisulfite sequencing PCR (BSP) following 24 h of LPS treatment. Inhibition of DNA methylation significantly enhanced LPS-induced IL-6 and IL-8 mRNA expression. LPS increased IL-6 and IL-8 mRNA expression, and decreased methylation levels of specific CpG sites at the IL-6 promoter (at -366 and -660) and the IL-8 promoter (at -120 and -48) after 24 h. Furthermore, LPS treatment for 24 h significantly increased DNMT1, DNMT3A, DNMT3B, and MeCP2 mRNA expression. Our results indicate that treating bovine endometrial cells with LPS induces the expression of IL-6 and IL-8 mRNA regulated by IL-6 and IL-8 promoter methylation.

16S rRNA gene sequencing reveals effects of photoperiod on cecal microbiota of broiler roosters.

Photoperiod is an important factor in stimulating broiler performance in commercial poultry practice. However, the mechanism by which photoperiod affects the performance of broiler chickens has not been adequately explored. The current study evaluated the effects of three different photoperiod regimes (short day (LD) = 8 h light, control (CTR) = 12.5 h light, and long day (SD) = 16 h light) on the cecal microbiota of broiler roosters by sequencing bacterial 16S rRNA genes. At the phylum level, the dominant bacteria were Firmicutes (CTR: 68%, SD: 69%, LD: 67%) and Bacteroidetes (CTR: 25%, SD: 26%, and LD: 28%). There was a greater abundance of Proteobacteria (p < 0.01) and Cyanobacteria (p < 0.05) in chickens in the LD group than in those in the CTR group. A significantly greater abundance of Actinobacteria was observed in CTR chickens than in SD and LD chickens (p < 0.01). The abundance of Deferribacteres was significantly higher in LD chickens than in SD chickens (p < 0.01). Fusobacteria and Proteobacteria were more abundant in SD chickens than in CTR and LD chickens. The predicted functional properties indicate that cellular processes may be influenced by photoperiod. Conversely, carbohydrate metabolism was enhanced in CTR chickens as compared to that in SD and LD chickens. The current results indicate that different photoperiod regimes may influence the abundance of specific bacterial populations and then contribute to differences in the functional properties of gut microbiota of broiler roosters.

Characterization of vaginal microbiota of endometritis and healthy sows using high-throughput pyrosequencing of 16S rRNA gene.

Endometritis is one of major challenges in reproduction infections caused by bacteria in sows. Understanding of the vaginal bacterial community between endometritis and healthy sows serves as a critical step to develop more effective ways to improve reproduction ability in pig industry. The aim of the present study is to evaluate and compare the vaginal microbiota of endometritis and healthy sows using high-throughput pyrosequencing of 16S rRNA gene. The main bacterium found at the phylum level were Firmicutes (60.88% vs. 45.86%), Proteobacteria (20.45% vs. 32.19%) and Bacteroidetes (9.19% vs. 12.99%) for healthy and endometritis sows, respectively. Most notable difference at the phylum level was the Proteobacteria which occupied high abundance in the endometritis sows but less abundance in the healthy sows. At the genus level, the highest abundant were Bacillus (27.13% vs. 16.15%), Paenibacillus (14.78% vs. 8.92%), Alkaliphilus (3.99% vs. 2.87%) and Cronobacter (4.04% vs. 2.37%), in healthy and endometritis sows, respectively. Notable differences were Escherichia-Shigella, Bacteroides, Fusobacterium and Clostridium_sensu_stricto_1 which were more abundant in the endometritis than the healthy sows respectively. The present results for the first time demonstrate vaginal microbial community of sows and indicate that endometritis affected the vaginal microbiota of sow.