Encapsulation of E. coli phage ZCEC5 in chitosan-alginate beads as a delivery system in phage therapy

© 2019, The Author(s). Bacteriophages can be used successfully to treat pathogenic bacteria in the food chain including zoonotic pathogens that colonize the intestines of farm animals. However, harsh gastric conditions of low pH and digestive enzyme activities affect phage viability, and accordingly reduce their effectiveness. We report the development of a natural protective barrier suitable for oral administration to farm animals that confers acid stability before functional release of bead-encapsulated phages. Escherichia coli bacteriophage ZSEC5 is rendered inactive at pH 2.0 but encapsulation in chitosan–alginate bead with a honey and gelatin matrix limited titer reductions to 1log10PFUmL−1. The encapsulated phage titers were stable upon storage in water but achieved near complete release over 4–5h in a simulated intestinal solution (0.1% bile salt, 0.4% pancreatin, 50mM KH2PO4 pH 7.5) at 37°C. Exposure of E. coli O157:H7 to the bead-encapsulated phage preparations produced a delayed response, reaching a maximal reductions of 4.2 to 4.8log10CFUmL−1 after 10h at 37°C under simulated intestinal conditions compared to a maximal reduction of 5.1log10CFUmL−1 at 3h for free phage applied at MOI = 1. Bead-encapsulation is a promising reliable and cost-effective method for the functional delivery of bacteriophage targeting intestinal bacteria of farm animals

The effect of the timing of exposure to Campylobacter jejuni on the gut microbiome and inflammatory responses of broiler chickens

Background Campylobacters are an unwelcome member of the poultry gut microbiota in terms of food safety. The objective of this study was to compare the microbiota, inflammatory responses, and zootechnical parameters of broiler chickens not exposed to Campylobacter jejuni with those exposed either early at 6 days old or at the age commercial broiler chicken flocks are frequently observed to become colonized at 20 days old. Results Birds infected with Campylobacter at 20 days became cecal colonized within 2 days of exposure, whereas birds infected at 6 days of age did not show complete colonization of the sample cohort until 9 days post-infection. All birds sampled thereafter were colonized until the end of the study at 35 days (mean 6.1 log10 CFU per g of cecal contents). The cecal microbiota of birds infected with Campylobacter were significantly different to age-matched non-infected controls at 2 days post-infection but generally the composition of the cecal microbiota were more affected by bird age as the time post infection increased. The effects of Campylobacter colonization on the cecal microbiota were associated with reductions in the relative abundance of OTUs within the taxonomic family Lactobacillaceae and the Clostridium cluster XIVa. Specific members of the Lachnospiraceae and Ruminococcaceae families exhibit transient shifts in microbial community populations dependent upon the age at which the birds become colonized by C. jejuni. Analysis of ileal and cecal chemokine/cytokine gene expression revealed increases in IL-6, IL-17A and Il-17F consistent with a Th17 response but the persistence of the response was dependent on the stage/time of C. jejuni colonization that coincide with significant reductions in the abundance of Clostridium cluster XIVa. Conclusions This study combines microbiome data, cytokine/chemokine gene expression with intestinal villus and crypt measurements to compare chickens colonized early or late in the rearing cycle to provide insights into the process and outcomes of Campylobacter colonization. Early colonization results in a transient growth rate reduction and pro-inflammatory response but persistent modification of the cecal microbiota. Late colonization produces pro-inflammatory responses with changes in the cecal microbiota that will endure in market ready chickens

The green production of eco-friendly silver with cobalt ferrite nanocomposite using Citrus limon extract

This paper reveals a novel and greener strategy to biosynthesize Cobalt-Ferrite-Silver trimetallic nanoparticles (Co-Fe-AgNPs) using the Citrus limon extract as a bio-reducing agent. Depending on the Transmission and Scanning Electron Microscopy (TEM and SEM), the prepared nanocomposites had a relatively small size with an average of 20 nm with a spherical shape. Moreover, The Energy Dispersive X-ray (EDX) showed the distribution of elements within the nanoparticles with various concentrations of C, K, S, O, Fe, Co and Ag. Finally, the potential ability of nanoparticles to combat the bacteria and biofilm formation was studied in-vitro. For example, a 125 µM nanocomposite is needed to kill Salmonella, and 62.5 µM inhibits its growth. Moreover, 30 µM is enough to inhibit biofilm formation. Furthermore, the anticancer activity was evaluated against MCF7 and HEPG2 cell lines with IC50 of 35.5 and 43.5 μg/mL, respectively. The findings suggest that Co-Fe-AgNPs could be a potential antibacterial and anticancer agent

Manufacture of Mudaffara Cheese. II. From Standardised Buffaloes Milk Fortified with Different Levels of Skim Milk Powder

Page(s): 2 (2), 92- 100, 9 Ref.Mudaffara cheese was made from standardised buffaloes' milk and buffaloes' milk fortified with 2.5% and 5% skim milk powder. A standard procedure for the production of Mudaffara cheese has been outlined. On addition of skim milk powder, the total solids of milk increased and consequently yield of cheese produced also increased. The chemical analysis of the product of the three milk samples showed significant differences in very few parameters, namely tyrosine and tryptophan contents of cheese. Organoleptic evaluation revealed no differences in all quality parameters tested for the three cheese samples (P<0.05). Skim milk powder could be added to buffaloes' milk at a rate of up to 5%, so as to increase yield, without affecting the chemical composition of the cheese or its sensory qualities.Khartoum University Pres

Head space analysis of volatile compounds from buffalo and ewe's Samna (Ghee) and butter oil

The volatile flavour compounds of buffalo and ewe's butter oil and Samna (Ghee) were investigated by head space analysis. Twenty-two compounds were identified. They are grouped under volatile free fatty acids, volatile carbonyls (methyl ketones and aldehydes), alcohol and esters. The volatile free fatty acids and methyl ketones are the major constituents in the flavour of Samna, while esters, aldehydes and alcohols are minor constituents. Samna is characterized by higher volatile free fatty acids and methyl ketones compared to butter oil. Samna prepared from buffalo's cutter contains higher free fatty acids and less methyl ketones compared to ewe's Samna. which may explain differences in their flavour intensity and characteristics. Samna prepared from the naturally fermented buffalo butter was characterized by significant quantities of diacetyl.Peer Reviewe

Using millimeter‐waves for rapid detection of pathogenic bacteria in food based on bacteriophage

The accessibility of a rapid method for detection and identification of food‐borne pathogens is crucial for food industry worldwide. Antibiotic resistance bacteria (eg, E. coli ) that can enter the food chain in different ways, can indeed survive on foods causing disease to humans. Hence, the introduction of a rapid detection technology becomes necessary for the food industry to ensure consumer safety, especially for products with short shelf lives. Bacteriophages can be used to detect and identify bacteria. In this study, a novel biosensor is proposed to detect pathogens by means of phage‐based baroreceptor. The biosensing technique is based on millimeter‐waves technology in the 30 to 60 GHz frequency range. The proposed biosensor can detect the pathogenic bacteria in different food samples by using a diamond‐shape microstrip slot antenna. The bacteriophage‐bacterium interaction is detected through the dynamic changes in transmission lines and antennas responses. The correctness of the antenna to detect E. coli in real food sample (tomato) is also investigated. The results indicate that, through the designed sensing elements, the transient interaction between bacteria and phage can effectively be detected. This sensing mechanism allows for a faster, more accurate, and low‐cost detection of pathogenic bacteria than traditional assays. Finally, the results are compared with previously reported sensing techniques

Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (&lt;48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life

The Synergistic Effect of Biosynthesized Silver Nanoparticles and Phage ZCSE2 as a Novel Approach to Combat Multidrug-Resistant Salmonella enterica

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 107 CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance

Isolation, Characterization, and Genomic Analysis of Three Novel E. coli Bacteriophages That Effectively Infect E. coli O18

Escherichia coli (E. coli) is one of the most common pathogenic bacteria worldwide. Avian pathogenic E. coli (APEC) causes severe systemic disease in poultry (Colibacillosis), and accordingly, has an extreme risk to the poultry industry and public health worldwide. Due to the increased rate of multi-drug resistance among these bacteria, it is necessary to find an alternative therapy to antibiotics to treat such infections. Bacteriophages are considered one of the best solutions. This study aimed to isolate, characterize, and evaluate the potential use of isolated bacteriophages to control E. coli infections in poultry. Three novel phages against E. coli O18 were isolated from sewage water and characterized in vitro. The genome size of the three phages was estimated to be 44,776 bp, and the electron microscopic analysis showed that they belonged to the Siphoviridae family, in the order Caudovirales. Phages showed good tolerance to a broad range of pH and temperature. The complete genomes of three phages were sequenced and deposited into the GenBank database. The closely related published genomes of Escherichia phages were identified using BLASTn alignment and phylogenetic trees. The prediction of the open reading frames (ORFs) identified protein-coding genes that are responsible for functions that have been assigned such as cell lysis proteins, DNA packaging proteins, structural proteins, and DNA replication/transcription/repair proteins