The Role of Bacteriophages in the Gut Microbiota: Implications for Human Health.

Bacteriophages (phages) are nano-sized viruses characterized by their inherent ability to live off bacteria. They utilize diverse mechanisms to absorb and gain entry into the bacterial cell wall via the release of viral genetic material, which uses the replication mechanisms of the host bacteria to produce and release daughter progeny virions that attack the surrounding host cells. They possess specific characteristics, including specificity for particular or closely related bacterial species. They have many applications, including as potential alternatives to antibiotics against multi-resistant bacterial pathogens and as control agents in bacteria-contaminated environments. They are ubiquitously abundant in nature and have diverse biota, including in the gut. Gut microbiota describes the community and interactions of microorganisms within the intestine. As with bacteria, parasitic bacteriophages constantly interact with the host bacterial cells within the gut system and have obvious implications for human health. However, it is imperative to understand these interactions as they open up possible applicable techniques to control gut-implicated bacterial diseases. Thus, this review aims to explore the interactions of bacteriophages with bacterial communities in the gut and their current and potential impacts on human health.

Exploitation of capsule system for colon targeted drug delivery of biopolymer-based microparticles: in vivo and in vitro applications.

The current study was to improve and control aceclofenac delivery prepared as biopolymer-based microparticles for effective colon-targeted drug delivery using modified gelatin capsules (MGCs) at different time intervals developed in two batches (C1 and C2). Microparticles were formulated with extracted mucuna gum using liquid paraffin oil (AC.LPO) and soybean oil (AC.SO) and evaluated in vitro for physicochemical performance and in vivo in rats. Encapsulation efficiency ranges from 54.48 ± 0.21% to 82.83 ± 0.22% for AC.LPO and 52.64 ± 0.11% to 80.36 ± 0.22% for AC.SO. SEM showed oblong and irregular shapes with porous and cracked surfaces. DSC showed low enthalpy and a very broad endothermic peak depicting high amorphous property. Delayed drug release was observed in the upper gastrointestinal tract with sustained release depicted in the lower gastrointestinal tract (GIT) using 3 and 9-h batch C1 of MGCs. AC.SO exhibited significantly (p < 0.05) higher anti-inflammatory activity (86%) than AC.LPO (77%). Hence, aceclofenac colon delivery could be improved and controlled using biopolymer-based colon-targeted microparticles delivered with MGCs.

Comparative analysis of the chicken IFITM locus by targeted genome sequencing reveals evolution of the locus and positive selection in IFITM1 and IFITM3.

BACKGROUND: The interferon-induced transmembrane (IFITM) protein family comprises a class of restriction factors widely characterised in humans for their potent antiviral activity. Their biological activity is well documented in several animal species, but their genetic variation and biological mechanism is less well understood, particularly in avian species. RESULTS: Here we report the complete sequence of the domestic chicken Gallus gallus IFITM locus from a wide variety of chicken breeds to examine the detailed pattern of genetic variation of the locus on chromosome 5, including the flanking genes ATHL1 and B4GALNT4. We have generated chIFITM sequences from commercial breeds (supermarket-derived chicken breasts), indigenous chickens from Nigeria (Nsukka) and Ethiopia, European breeds and inbred chicken lines from the Pirbright Institute, totalling of 206 chickens. Through mapping of genetic variants to the latest chIFITM consensus sequence our data reveal that the chIFITM locus does not show structural variation in the locus across the populations analysed, despite spanning diverse breeds from different geographic locations. However, single nucleotide variants (SNVs) in functionally important regions of the proteins within certain groups of chickens were detected, in particular the European breeds and indigenous birds from Ethiopia and Nigeria. In addition, we also found that two out of four SNVs located in the chIFITM1 (Ser36 and Arg77) and chIFITM3 (Val103) proteins were simultaneously under positive selection. CONCLUSIONS: Together these data suggest that IFITM genetic variation may contribute to the capacities of different chicken populations to resist virus infection.

Chitosan/alginate microparticles for the oral delivery of fowl typhoid vaccine: Innate and acquired immunity.

Oral fowl typhoid (FT) vaccine is necessary for improved flock vaccinations and economic growth. This study was undertaken to evaluate the immune responses of birds given oral fowl typhoid vaccine coated with chitosan/alginate microparticles and comparing it with the conventional subcutaneous route of administration. Preliminary studies were done to evaluate the particle size, encapsulation efficiency and agglutination. Sixty day-old chicks were divided into three groups of twenty birds each. This comprised a negative control group NEG 451 (non-vaccinated and non-challenged used as control for cytokine quantification), SC 634 (live 9R vaccine by the injection route) and OCV 567 (live 9R vaccine coated with chitosan/alginate microparticles). Vaccination was done at 10 weeks and 14 weeks of age followed by challenge at 16 weeks of age. IgG was measured using ELISA. mRNA fold expression of IFN-γ in spleen was calculated using qRT-PCR. Particle sizes ranged between 0.55 µm and 10 µm. Encapsulation efficiency was above 60%. ELISA showed E-values of 0.10 ±â€¯0.14, 0.07 ±â€¯0.01 and 0.02 ±â€¯0.01 for OCV 567, SC 634 and NEG 451 respectively after primary vaccination. Also E-values were 0.25 ±â€¯0.16, 0.19 ±â€¯0.04 and 0.0008 ±â€¯0.005 for SC 634, OCV 567 and NEG451 respectively after boost vaccination. The expression of IFN-γin spleen using 2-ΔΔ CT calculation was upregulated with values of 1.97 and 0.75 for OCV 567 and SC 634 respectively. After challenge with the 85-kb virulence plasmid SG9, there was 100% protection of the birds in both OCV 567 and SC 634 groups with no mortality. In conclusion, there was no significant difference at p < 0.05 of the means ±â€¯SD in immune responses between the oral fowl typhoid vaccine coated with chitosan/alginate microparticles and the subcutaneous route of administration. However, it is noteworthy to mention that the protective efficacy of the oral route is due to the chitosan/alginate biopolymers which coated the vaccine preventing destruction in the gastrointestinal tract.