BACKGROUND: Infections caused by Salmonella spp. remain an important public health threat especially in developing countries. In recent years, rapid emergence of antibiotics resistance has resulted in the inefficacy of available treatment options which has led to exponential increase in mortality and economic burden. The study aimed to screen Salmonella spp. for resistance genes to frequently used antibiotics and establishing the distribution of these genes across Niger State. METHODS: Ninety-eight samples comprising 72 raw meat and 26 stool samples were analyzed for the presence of Salmonella spp. Antimicrobial susceptibility of Salmonella isolates was determined by the Kirby-Bauer disc diffusion method and amplification of resistance genes namely bla(TEM), catP and gyrA were carried out using nested polymerase chain reaction (PCR) technique. RESULTS: Thirty-one (31.6%) isolates were positive for Salmonella spp. The distributions of the isolates were 22 of 31 (70.97%) in raw meat and nine of 31 (29.03%) in stool. Salmonella isolates were susceptible to ciprofloxacin (93.5%) but highly resistant to ampicillin (100%), chloramphenicol (96.8%), nalidixic acid (93.5%), tetracycline and ceftriaxone (90.3%), erythromycin (77.4%), cotrimoxazole (64.5%). High levels of bla(TEM) and catP genes and relatively low gyrA gene distributions were observed in isolates from stool and raw meat samples across the state. CONCLUSIONS: These data suggest that there is a high prevalence of ampicillin and chloramphenicol resistance by Salmonella spp. as shown by high levels of bla(TEM), gyrA and catP genes while gyrA distribution is rare across Niger State.
Hepatic fibrosis is characterized by the disruption of normal liver architecture due to proliferation of hepatic myofibroblasts, and excess of extracellular matrix (ECM) deposition. The final stage of liver diseases, cirrhosis, is common across the spectrum of chronic hepatitis such as viral hepatitis, alcoholic and non-alcoholic hepatitis, and autoimmune hepatitis. Although several molecular mechanisms involved in fibrogenesis are common in all etiologies, some of them may differ for certain aspects. A key feature of hepatic fibrosis is the activation and proliferation of hepatic stellate cells (HSCs) that become able to produce extracellular matrix ECM components. The altered ratio between ECM deposition and matrix turnover contributes to fibrogenesis with the risk of progression of liver disease. Fibrogenesis enhances an inflammatory process contributing to the activation of immune cells that reach the site of injury releasing pro-inflammatory cytokines. Moreover, other cells contribute to the activation of HSCs, for example Kupffer cells (KCs) (resident macrophages), endothelial cells and hepatocytes. In this review we summarize molecular mechanisms of hepatic fibrogenesis in the setting of the main chronic liver diseases (CLD) (alcoholic hepatitis, viral hepatitis and non-alcoholic steatohepatitis) focusing on the emerging issues involved in the onset and progression of liver damage.
BACKGROUND: Bacteriophages are a long-overlooked component of the virobiota that have the potential to shape mammalian immunity. The aim of our study was to identify a bacteriophages communities in urinary tract infections (UTIs). METHODS: We sampled the urine from 151 children having urinary tract infections, and 49 healthy controls. We decide to investigate at least one of the member of Caudovirales and Microviridae by real time PCR on urine. RESULTS: We demonstrate that bacteriophage phi V10 was more abundant in UTIs than in healthy subjects (P<0.004) and at the contrary, bacteriophage phi FL4A was more abundant in healthy subjects that in UTI samples. CONCLUSIONS: We demonstrated in UTIs an abundance of bacteriophage phi V10. Further studies will be necessary to understand how resident prokaryotic phages and eukaryotic viruses shape commensal bacterial communities.
BACKGROUND: Mannanase has been used for the hydrolysis of mannan, which is produced by many microorganisms including bacteria. The purified enzyme can be utilized in the production of high-value product such as mannooligosaccharides as prebiotics. This study aimed at purification of extracellular beta-mannanase from Proteus vulgaris using an aqueous polymer impregnated resin system. METHODS: The effect of extraction solution (potassium phosphate, sodium citrate and sodium acetate) on the stability of beta-mannanase activity was studied. The parameters which influence the purification performance such as molecular weight and concentration of PEG, concentration of salts, pH of salt, crude loading and extraction time were investigated using one-factor-at-a-time (OFAT). The effect of type and concentration of salts and pH on purification fold and yield in back extraction were also evaluated. RESULTS: beta-mannanase from Proteus vulgaris was purified using aqueous impregnated resin system with a purification fold of 10.7 and yield of 33.7% at 30% (w/w) PEG 4000 (g/mol) impregnated resins, 20% (w/w) of potassium phosphate at pH 7 with 4% (w/w) of NaCl. The back-extraction solution was 20% (w/w) potassium phosphate at pH 7. CONCLUSIONS: In conclusion, aqueous impregnated resin system offers the possibility to tailor a selective and customized purification system for beta-mannanase.
Different strategies are used for plant transformation, including electroporation, particle bombardment, polyethylene-mediated, Agrobacterium-mediated, nuclease-induced, RNA interference, and recombinase technology. Unfortunately, even after decades of developments in these transformation techniques, the regeneration potential remains troublesome in most of the crops due to their intricate genomic pattern. Further, the risk factors associated with human health and environment due to the presence of antibiotic resistance genes and foreign DNA in genetically modified (GM) crops restricts their acceptance and commercialization. These concerns seek the researcher's attention to develop new strategies and advanced tools for crop transformation. For example, the use of cisgenesis and intragenesis where the genetic material is derived from the species itself or from sexually compatible species and the engineering of existing Agrobacterium and other microbes like Rhizobium etli and Ensifer adhearens which facilitate the transfer of DNA/protein into the host plant cells, would pave the way for commercialization of GM crops in the areas where these were poorly accepted in the past. Besides, novel genome editing tools are developed, which produce crops with improved resistance to different biotic and abiotic stresses, which ultimately results in high yield. These developments have facilitated deep insights into plant biology and renovated commercial agriculture. Nonetheless, further simplification and optimization of these crop transformation strategies are essential to minimize the culture time and barriers. This review discusses the recent advancements in crop transformation and highlights several issues to be addressed for further improvement of the existing crop genome editing strategies.
