Silica vesicles increase stability of Salmonella-specific phages isolated from chicken in environments mimicking the gastrointestinal tract

Non-typhoidal Salmonella (NTS) enterica serovar Enteritidis is one of the major causes of foodborne infections worldwide. This NTS serovar is mainly transmitted to humans through poultry products. Bacteriophages (phages) are a promising alternative to antibiotics to reduce NTS incidences in poultry farms. The ability to survive the harsh environment encountered in the chicken gastrointestinal tract (GIT), such as low pH, high temperature and enzymatic digestion, can be valuable in selecting phages with high therapeutic potential. In this study, we characterized 13 newly isolated Kenyan S. Enteritidis-specific phages for their ability to survive in pH-adjusted media, different temperatures, and simulated gastric and intestinal fluids (SGF and SIF, respectively). Furthermore, we evaluated the possibility of using silica vesicles (SV) to increase the stability of these phages in these environments. All phages were relatively stable from pH 4 to 12 and from 25℃ to 42℃ following 12 hours of incubation. At pH 3, phages lost up to 3 logs in viral titres after three hours of incubation. They remained more stable at pH 9, with phage titres 2 logs higher than at pH 3. In SGF, they were stable for 20 minutes; afterwards, they started losing their viability up to 5 logs, while they were relatively stable in SIF for up to two hours. Moreover, significant differences were observed among the different phages in surviving these environments. Encapsulating phages with SV demonstrated a slow but long rate of phage release upon adsorption for 96 hours. Preliminary data indicate that SV 140 C18 can protect phages longer than other silica vesicles tested. In contrast, free phages in SGF had an average reduction of 7 logs PFU/ml after 60 minutes of incubation. These data suggest that a number of these phages can potentially survive through the chicken GIT and that SV can be an ideal technology to prolong the stability of phages in acidic environments

Phages for Africa: The potential benefit and challenges of phage therapy for the livestock sector in sub-Saharan Africa

One of the world’s fastest-growing human populations is in Sub-Saharan Africa (SSA), accounting for more than 950 million people, which is approximately 13% of the global population. Livestock farming is vital to SSA as a source of food supply, employment, and income. With this population increase, meeting this demand and the choice for a greater income and dietary options come at a cost and lead to the spread of zoonotic diseases to humans. To control these diseases, farmers have opted to rely heavily on antibiotics more often to prevent disease than for treatment. The constant use of antibiotics causes a selective pressure to build resistant bacteria resulting in the emergence and spread of multi-drug resistant (MDR) organisms in the environment. This necessitates the use of alternatives such as bacteriophages in curbing zoonotic pathogens. This review covers the underlying problems of antibiotic use and resistance associated with livestock farming in SSA, bacteriophages as a suitable alternative, what attributes contribute to making bacteriophages potentially valuable for SSA and recent research on bacteriophages in Africa. Furthermore, other topics discussed include the creation of phage biobanks and the challenges facing this kind of advancement, and the regulatory aspects of phage development in SSA with a focus on Kenya

Gender-responsive design of bacteriophage products to enhance adoption by chicken keepers in Kenya

Women and men keeping chickens in Kenya aspire to have a source of income, feed their families healthy food, and grow their businesses. Managing animal diseases and minimizing input costs enable their success. This study uses qualitative methods to recommend design opportunities for a veterinary product under development in Kenya that contains bacteriophages (phages) that target pathogenic Salmonella strains responsible for fowl typhoid, salmonellosis, and pullorum in chickens and foodborne illness in people. Our findings revealed the interplay between gender and two production systems: free-range and semi-intensive. Chicken keepers in both systems could benefit from phages combined with the orally administered Newcastle disease vaccine, one of the most commonly used preventive veterinary interventions, or phages as a treatment for fowl typhoid. Oral administration is less labor intensive, with greater benefits for women who have less control over family labor and reported doing more care tasks themselves. Men in free-range systems usually pay for veterinary inputs. In semi-intensive production systems, a phage-based product used prophylactically could be an alternative to expensive, intramuscular fowl typhoid vaccines. Keeping layers was common for women in semi-intensive systems, as they are more economically impacted by reduced laying caused by bacterial diseases. Awareness of zoonoses was low, but men and women were concerned about the negative health effects of drug residues in meat and eggs. Therefore, highlighting the lack of a withdrawal period for a phage product may appeal to customers. Antibiotics are used to both treat and prevent diseases, and phage products will need to do both to compete in the Kenyan market. These findings guide the ongoing design of a phage-based product with the goal of introducing a new veterinary product that meets the diverse needs of chicken keepers in Africa and serves as an alternative or complement to antibiotics

A New Model of Discrete-Continuous Bivariate Distribution with Applications to Medical Data

The bivariate Poisson exponential-exponential distribution is an important lifetime distribution in medical data analysis. In this article, the conditionals, probability mass function (pmf), Poisson exponential and probability density function (pdf), and exponential distribution are used for creating bivariate distribution which is called bivariate Poisson exponential-exponential conditional (BPEEC) distribution. Some properties of the BPEEC model are obtained such as the normalized constant, conditional densities, regression functions, and product moment. Moreover, the maximum likelihood and pseudolikelihood methods are used to estimate the BPEEC parameters based on complete data. Finally, two data sets of real bivariate data are analyzed to compare the methods of estimation. In addition, a comparison between the BPEEC model with the bivariate exponential conditionals (BEC) and bivariate Poisson exponential conditionals (BPEC) is considered

Modified XLindley distribution: Properties, estimation, and applications

This article aims to introduce the inverse new XLindley distribution, a further extension of the new XLindley distribution. The article explores various properties of the proposed model, such as the quantile function, stochastic orders, entropies, fuzzy reliability, moments, and stress–strength estimation. The paper also compares different methods of estimating the parameters of the proposed model and evaluates their performance using a simulation study. Moreover, the paper demonstrates the usefulness of the proposed model by applying it to two real datasets. The article shows that the proposed model fits the data better than seven existing models based on model selection criteria, goodness-of-fit test statistics, and graphical visualizations. The paper concludes that the new model can be a valuable tool for modeling and analyzing hazard functions or survival data in various fields and contributing to probability theory and statistical inferences

Salmonella Enteritidis bacteriophages isolated from Kenyan poultry farms demonstrate time-dependent stability in environments mimicking the chicken gastrointestinal tract

Multi-drug resistant (MDR) Salmonella enterica Enteritidis is one of the major causes of foodborne illnesses worldwide. This non-typhoidal Salmonella (NTS) serovar is mainly transmitted to humans through poultry products. Bacteriophages (phages) offer an alternative to antibiotics for reducing the incidence of MDR NTS in poultry farms. Phages that survive the harsh environment of the chicken gastrointestinal tract (cGIT), which have low pH, high temperatures, and several enzymes, may have a higher therapeutic or prophylactic potential. In this study, we analysed the stability of 10 different S. Enteritidis phages isolated from Kenyan poultry farms in different pH-adjusted media, incubation temperatures, as well as simulated gastric and intestinal fluids (SGF and SIF, respectively). Furthermore, their ability to persist in water sources available in Kenya, including river, borehole, rain and tap water, was assessed. All phages were relatively stable for 12 h at pHs ranging from 5 to 9 and at temperatures ranging from 25 °C to 42 °C. At pH 3, a loss in viral titre of up to three logs was observed after 3 h of incubation. In SGF, phages were stable for 20 min, after which they started losing infectivity. Phages were relatively stable in SIF for up to 2 h. The efficacy of phages to control Salmonella growth was highly reduced in pH 2- and pH 3-adjusted media and in SGF at pH 2.5, but less affected in SIF at pH 8. River water had the most significant detrimental effect on phages, while the other tested waters had a limited impact on the phages. Our data suggest that these phages may be administered to chickens through drinking water and may survive cGIT to prevent salmonellosis in poultry

Weighted power Maxwell distribution: Statistical inference and COVID-19 applications.

During the course of this research, we came up with a brand new distribution that is superior; we then presented and analysed the mathematical properties of this distribution; finally, we assessed its fuzzy reliability function. Because the novel distribution provides a number of advantages, like the reality that its cumulative distribution function and probability density function both have a closed form, it is very useful in a wide range of disciplines that are related to data science. One of these fields is machine learning, which is a sub field of data science. We used both traditional methods and Bayesian methodologies in order to generate a large number of different estimates. A test setup might have been carried out to assess the effectiveness of both the classical and the Bayesian estimators. At last, three different sets of Covid-19 death analysis were done so that the effectiveness of the new model could be demonstrated

Plots of the mean, variance, skewness, and kurtosis of the HTLL model with <i>β</i> = 2.

Plots of the mean, variance, skewness, and kurtosis of the HTLL model with β = 2.</p