ABSTRACT
The complete genome sequence of the unique virulent bacteriophage BRock, isolated from compost on Streptomyces sp. strain SFB5A, was determined. BRock is a myovirus with a 112,523-bp genome containing a GC content of 52.3%. There were 188 protein-coding genes predicted, including structural and enzymatic proteins, but none predicted for lysogeny. Twenty-nine tRNAs were predicted.
ABSTRACT
Bacteriocins produced by lactic acid bacteria are safer alternatives to the more popularly used chemical preservatives which exhibit several adverse effects. The bacteriocins have an advantage of being efficient in controlling food pathogens without possessing any side-effects. However, the bacteriocins have a limitation of exhibiting a narrow antimicrobial spectrum and having a high-dosage requirement. With an aim to combat these limitations, the present study involved the biosynthesis of bacteriocin-capped nanoparticles, using two bacteriocins (Bac4463 and Bac22) extracted and purified from Lactobacillus strains. Nanoconjugates synthesised at optimum conditions were characterized using various physico-chemical techniques. The interaction of bacteriocin-capped silver nanoparticles with the pathogenic bacteria was observed using scanning electron microscopy, wherein the deformed and elongated cells were clearly visible. In vitro antimicrobial efficacy of both Bac4463-capped silver nanoparticles and Bac22-capped silver nanoparticles against different food pathogens was observed to be enhanced in comparison to the antimicrobial activity of bacteriocins alone. Minimum inhibitory concentration was observed to be as low as 8â µg/ml for Bac4463-capped silver nanoparticles against Staphylococcus aureus, and 2â µg/ml for Bac22-capped silver nanoparticles against Shigella flexneri. This study, therefore, recommends the use of bacteriocin-capped nanoparticles as food preservatives to control the growth of food spoiling bacteria.
Subject(s)
Anti-Bacterial Agents , Bacteriocins , Metal Nanoparticles/chemistry , Silver/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacteria/cytology , Bacteria/drug effects , Bacteriocins/chemistry , Bacteriocins/pharmacology , Microbial Sensitivity TestsABSTRACT
Upsurge in the instances of antibiotic-resistant uropathogenic Escherichia .coli (UPECs) strains has repositioned the attention of researchers towards a century old antimicrobial approach popularly known as phage therapy. Rise of extended spectrum beta lactamase (ESBL) and biofilm producing strains has added another step of hurdle in treatment of uropathogens with conventional antibiotics, thus providing a further impetus for search for exploring new therapeutic measures. In this direction, bacteriophages, commonly called phages, are recently being considered as potential alternatives for treatment of UPECs. Phages are the tiniest form of viruses which are ubiquitous in nature and highly specific for their host. This review discusses the possible ways of using natural phages, genetically engineered phages, and phage lytic enzymes (PLEs) as an alternative antimicrobial treatment for urinary tract infections. The review also sheds light on the synergistic use of conventional antibiotics with phages or PLEs for treatment of uropathogens. These methods of using phages and their derivatives, alone or in combination with antibiotics, have proved fruitful so far in in vitro studies. However, in vivo studies are required to make them accessible for human use. The present review is a concerted effort towards putting together all the information available on the subject.
Subject(s)
Bacteriophages/physiology , Escherichia coli Infections/therapy , Phage Therapy , Urinary Tract Infections/therapy , Uropathogenic Escherichia coli/virology , Animals , Bacteriophages/genetics , Escherichia coli Infections/microbiology , Humans , Urinary Tract Infections/microbiology , Uropathogenic Escherichia coli/genetics , Uropathogenic Escherichia coli/physiologyABSTRACT
Immunotherapy drugs work by stimulating the patient's own immune system to recognize and destroy cancer cells. This subclass of drugs is increasingly administered to patients with advanced melanoma. They are also commonly incorporated into other cancer therapies such as non-small cell lung cancer, renal cancer, head and neck cancers and Hodgkin lymphoma. The most commonly administered immunotherapeutic agents in the treatment of melanoma include programmed cell death protein 1 (PD-1) inhibitors, cytotoxic T-lymphocyte antigen 4 (CTLA-4) inhibitors and a subclass of cytokines. During treatment with these antibodies, a unique set of adverse effects may occur which are often called immune-related adverse events (irAEs). It is vital for radiologists to be aware of and document these side effects during routine staging or body imaging during therapy. Some of these include pneumonitis, colitis, hypophysitis, lymphadenopathy or sarcoid-like syndrome and myositis. IrAEs such as sarcoid-like lymphadenopathy can mimic progression of disease. Serious side effects are seen in less than 10% of patients, and typically emerge between 6 and 12 weeks after commencing treatment. The clinical manifestations of these side effects typically vary from mild to severe and so do the radiological findings. Patients with mild side effects are often treated successfully with systemic corticosteroids, while severe cases require cessation of immunotherapy. We provide a pictorial article on the common irAEs and the associated radiological manifestations.