Antibiotics are frequently used in food animal production in developing countries to promote the well-being and growth of animals. This practice provides some economic benefits to producers and consumers at large. Nevertheless, this practice is also associated with a number of concerns. A major concern has been that repeatedly exposing these animals to small doses of antibiotics contributes significantly to antimicrobial resistance, since a good fraction of the antibiotics used are the same or surrogates of antibiotics used in human therapeutic practices. Studies over decades have shown an explicit relationship between antimicrobial use and antimicrobial resistance in veterinary science. Many antibiotics can be purchased over the counter in African countries, and antibiotic resistance is an important issue to address in this region. This review examines some of the risks and benefits associated with antibiotic use in food animals. We conclude that the use of antibiotics in food animal production constitutes a major contributing factor to the current antimicrobial resistance crisis and that antibiotics should only be used for the treatment of sick animals based on prior diagnosis of disease.

We demonstrate aqueous phase biosynthesis of phase-pure metallic copper nanoparticles (CuNPs) using a silver resistant bacterium Morganella morganii. This is particularly important considering that there has been no report that demonstrates biosynthesis and stabilization of pure copper nanoparticles in the aqueous phase. Electrochemical analysis of bacterial cells exposed to Cu²⁺ ions provides new insights into the mechanistic aspect of Cu²⁺ ion reduction within the bacterial cell and indicates a strong link between the silver and copper resistance machinery of bacteria in the context of metal ion reduction. The outcomes of this study take us a step closer towards designing rational strategies for biosynthesis of different metal nanoparticles using microorganisms.

Anisakidosis is a zoonotic parasitosis induced by members of the family Anisakidae. The anisakid genera includes Anisakis, Pseudoterranova, Hysterothylacium and Contracaecum. The final definitive hosts of these nematodes are marine mammals with a complex life cycle. These nematode parasites use different crustaceans and fish species as intermediate or paratenic hosts and humans are accidental hosts. Human anisakiasis, the infections caused by members of the genus Anisakis, occurs, when seafoods, particularly fish, contaminated with the infective stage (third stage larvae [L3]) of this parasite, are consumed. Pseudoterranovosis, on the other hand is induced by members of the genus Pseudoterranova. These two genera of anisakids have been implicated in human disease globally. There is a rise in reports of gastro-intestinal infections accompanied by allergic reactions caused by Anisakis simplex and Anisakis pegreffii. This review provides an update on current knowledge on Anisakis as a food-borne parasite with special focus on the increasingly reported diversity of fish and crustacean hosts, allergens and immunological cross-reactivity with invertebrate proteins rendering this parasite a significant public health issue.

Over the last century, the successful attenuation of multiple bacterial and viral pathogens has led to an effective, robust and safe form of vaccination. Recently, these vaccines have been evaluated as delivery vectors for heterologous antigens, as a means of simultaneous vaccination against two pathogens. The general consensus from published studies is that these vaccine vectors have the potential to be both safe and efficacious. However, some of the commonly employed vectors, for example Salmonella and adenovirus, often have pre-existing immune responses in the host and this has the potential to modify the subsequent immune response to a vectored antigen. This review examines the literature on this topic, and concludes that for bacterial vectors there can in fact, in some cases, be an enhancement in immunogenicity, typically humoral, while for viral vectors pre-existing immunity is a hindrance for subsequent induction of cell-mediated responses.

Genetically attenuated microorganisms, including pathogenic and commensal bacteria, can be engineered to carry and deliver heterologous antigens to elicit host immunity against both the vector as well as the pathogen from which the donor gene is derived. These live attenuated bacterial vectors have been given much attention due to their capacity to induce a broad range of immune responses including localized mucosal, as well as systemic humoral and/or cell-mediated immunity. In addition, the unique tumor-homing characteristics of these bacterial vectors has also been exploited for alternative anti-tumor vaccines and therapies. In such approach, tumor-associated antigen, immunostimulatory molecules, anti-tumor drugs, or nucleotides (DNA or RNA) are delivered. Different potential vectors are appropriate for specific applications, depending on their pathogenic routes. In this review, we survey and summarize the main features of the different types of live bacterial vectors and discussed the clinical applications in the field of vaccinology. In addition, different approaches for using live attenuated bacterial vectors for anti-cancer therapy is discussed, and some promising pre-clinical and clinical studies in this field are outlined.