In vitro Antibacterial Efficacy of Non-Antibiotic Growth Promoters in Poultry Industry

Antibiotic growth promoters (AGPs) have been used for many years as supplements in various livestock diets, including those for poultry. However, the use of AGPs in feed was also associated with an increasing number of antibiotic-resistant bacteria in livestock. In this study, the in vitro antibacterial efficacies of eight commercially available non-AGPs suitable for use in poultry were investigated. Assessments included a combination of antibacterial activity assays and estimations of the minimal inhibitory and bactericidal concentrations along with scanning electron microscopy analysis. The results showed that the probiotic, CloStat® exerted a bacteriostatic effect against all tested bacteria, namely Salmonella Typhimurium, Escherichia coli, Staphylococcus aureus, and Clostridium perfringens, whereas Gallipro Tect® and Bacillus Blend® demonstrated bacteriostatic activity towards most of the pathogens tested. Other commercial non-AGPs, Sangrovit®, Fysal®, and Mix oil blend® showed a stronger or equal antibacterial activity compared to the positive control (AGP Maxus® G100) againsts all bacteria tested, except C. perfringens. Nor-Spice AB® and Varium™ did not show any significant effect against the tested bacteria. Several of the tested AGP substitutes exhibited good antibacterial efficiency against pathogenic bacteria and thus may be good candidates for second-stage in vivo investigations into reducing pathogen colonization in broilers

Novel Eco-Synthesis of PD Silver Nanoparticles: Characterization, Assessment of Its Antimicrobial and Cytotoxicity Properties

Nanomedicine is growing due to the development of new medical diagnostic tools and new nanostructure-based therapies that exert direct biological action or function as pharmacological carriers. Nanoparticles (NPs) synthesis provides an eco-friendly approach for different applications. Among NPs, silver NPs (AgNPs) are gaining considerable research interest due to their broad range of activity and their usability in the medical and biotechnology fields. In this study, a new AgNP synthesis method was developed using an aqueous pigeon dropping (PD) extract in silver nitrate (AgNO3). The rapid of AgNPs yield was detected visually. Analysis of UV-vis spectroscopy, energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS) and electron microscopy (TEM) transmission showed a spherical or near spherical shape of AgNPs with mean size of 135 nm. AgNPs antimicrobial activities (anti-bacterial and anti-fungal) were determined using agar well diffusion method. These NPs further screened for anticancer activity in vitro using A-549 and MCF-7 cell lines. The results showed that the inhibition zone for the obtained PD AgNPs versus Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus were 26, 18, 17 and 15 mm, respectively. PD AgNPs showed the highest antifungal effect against Aspergillus flavus and the lowest effect against Penicillium griseofulvum. In vitro anti-cancer activities showed that the inhibitory concentration of 50% (IC50) of AgNPs was 10.3 ± 1.15 and 12.19 ± 0.75 µg mL−1 against A-549 and MCF-7 cancer cell lines, respectively

In vitro biological activity of Hydroclathrus clathratus and its use as an extracellular bioreductant for silver nanoparticle formation

The adaptive nature of algae results in producing unique chemical components that are gaining attention due to their efficiency in many fields and abundance. In this study, we screened the phytochemicals from the brown alga Hydroclathrus clathratus and tested its ability to produce silver nanoparticles (AgNPs) extracellularly for the first time. Lastly, we investigated its biological activity against a variety of bacteria. The biosynthesized nanoparticles were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy, and energy-dispersive spectroscopy. The biological efficacy of AgNPs was tested against eighteen different bacteria, including seven multidrug-resistant bacteria. Phytochemical screening of the alga revealed the presence of saturated and unsaturated fatty acids, sugars, carboxylic acid derivatives, triterpenoids, steroids, and other components. Formed AgNPs were stable and ranged in size between 7 and 83 nm and presented a variety of shapes. Acinetobacter baumannii, Staphylococcus aureus, Methicillin-resistant S. aureus (MRSA), and MDR A. baumannii were the most affected among the bacteria. The biofilm formation and development assay presented a noteworthy activity against MRSA, with an inhibition percentage of 99%. Acknowledging the future of nano-antibiotics encourages scientists to explore and enhance their potency, notably if they were obtained using green, rapid, and efficient methods

Influence of prebiotic yeast cell wall extracts on growth performance, carcase attributes, biochemical metabolites, and intestinal morphology and bacteriology of broiler chickens challenged with Salmonella typhimurium and Clostridium perfringens

The current experiment was conducted to examine the efficacy of yeast cell wall (YCW) supplementation on growth performance, carcase characteristics, serum biochemistry, ileum histological structure, and caecum bacterial populations of broilers subjected to Salmonella typhimurium (S. typhimurium) and Clostridium perfringens (C. perfringens) challenges from 11 to 35 d of age. A total of 360 mixed-sex Ross 308 broilers were randomly distributed to 5 treatments with 12 replications of 6 birds each as follows: control with no additive or challenge; S. typhimurium challenge; C. perfringens challenge; S. typhimurium + YCW; C. perfringens + YCW. The YCW was supplemented at a level of 0.5 g/kg. Compared to the control group, the unsupplemented challenged groups had deteriorated average daily gain, feed conversion ratio (FCR), and European production efficiency factor (EPEF) during all experimental periods (p < .001) and reduced dressing percentage, glucose (GLU) concentration (p < .001), and Lactobacillus population (p < .01). Moreover, the S. typhimurium-challenged group had reduced total protein (TP) level and elevated S. typhimurium count (p < .001), while the C. perfringens-challenged group showed decreased liveability (p < .001) and crypt depth (p < .05) and increased C. perfringens count (p < .01) than the control group. Supplementation of YCW under S. typhimurium challenge improved FCR and EPEF during all experimental periods (p < .001), levels of TP, GLU (p < .001), and globulin (p < .05), villus height (VH) (p < .001), and villus surface area (p < .01) and reduced S. typhimurium count (p < .001). Broilers fed YCW and challenged with C. perfringens exhibited improved FCR during grower and overall periods, EPEF during all experimental periods, liveability, GLU level, and VH (p < .001). In conclusion, dietary supplementation of YCW could ameliorate the harmful impacts of disease challenges on the growth efficiency of broilers. Highlights Saccharomyces cerevisiae yeast-derived prebiotics have been experimented and utilised as a potential alternative to antibiotics in poultry diets. Challenge with Salmonella typhimurium or Clostridium perfringens diminished growth efficiency and compromised intestinal health in broiler chickens. The dietary supplementation of yeast cell wall could reduce the negative effects of pathogens on broiler performance

Bacillus subtilis PB6 based probiotic supplementation plays a role in the recovery after the necrotic enteritis challenge.

In poultry production, birds are raised under intensive conditions, which can enable rapid spread of infections, with Clostridium perfringens-caused necrotic enteritis (NE) being one of the most devastating for the industry. The current investigation was conducted to evaluate the effectiveness of Bacillus subtilis PB6 probiotic supplementation on bird's post NE recovery, based on chicken performance, cecal microbiota composition, ileum histomorphometric measurements, and short-chain fatty acid production in the cecum of the birds that were challenged with NE mid-production. Birds were split into four groups, including a negative control, positive control challenged with C. perfringens, group supplemented with B. subtilis probiotic, and NE challenged birds supplemented with B. subtilis probiotic. Following NE challenge birds were allowed to reach the end of production time at 40 days, and samples were collected to estimate if probiotic supplementation resulted in better post-NE recovery. Intestinal lesion score across the duodenum, jejunum, and ileum indicated that at the end of production timeline NE challenged birds supplemented with B. subtilis probiotic had lower intestinal lesion scores compared to NE challenged birds without probiotic supplementation implying improved recovery. Probiotic supplementation improved performance of NE challenged birds only in the post-NE recovery stage. NE challenged birds had a significant increase in cecal propionic acid, which was not observed in NE challenged birds supplemented with B.subtilus. Both B. subtilis supplemented groups (challenged and unchanged) were characterized by a significant rise in cecal acetic and butyric acid. Our results demonstrate that B. subtilis supplementation can assist the birds in dealing with NE outbreak and long term recovery

Evaluation of antimicrobial activity of secondary metabolites of fungi isolated from Sultanate Oman soil

Seven fungal species were isolated from soil samples collected from the University of Sultan Qaboos, Muscat, Sultanate of Oman. The fungal isolates were identified as Aspergillus athecius, A. terreus var. africans, A. flavus, A. terreus, A. foetidus, Fusarium chlamydosporum and F. nygamai. Phytochemical and chromatographic investigation showed variety of secondary metabolites in all of the fugal extracts (extra and intra cellular). The antimicrobial activity of internal and external extracts of the isolated fungal species were screened against Candida albicans, C. glabrata, C. parapsilosis, C. tropicalis, Pseudomonas aeruginosa, Lactobacillus acidophilus, Streptococcus gordonii, S. mutans. The antimicrobial activity of external secondary metabolites was generally better than the internal metabolites. The highest antimicrobial activity (32 mm, 30 mm and 29 mm) was obtained from external secondary metabolites of Aspergillus flavus against Candida tropicals, Candida parapsilosis and Candida albicans, respectively. Keywords: Aspergillus flavus, Phytochemical contents, Intra cellular, Extra cellular, Fusarium chlamydosporum, Candida albicans, Antimicrobial, Soil microbes, Aspergillus, Fusariu

In-silico studies of glutathione peroxidase4 activators as candidate for multiple sclerosis management

Multiple sclerosis (MS) is an autoimmune and inflammatory demyelinating disease of the central nervous system (CNS) that affects approximately 2.8 million people worldwide. Although numerous studies have been conducted to investigate novel therapeutic targets and lead compounds, few drug choices are available to treat MS patients. The etiology of this disease is still poorly understood. However, oxidative stress is proposed as one of the underlining pathology. The neuronal antioxidant enzyme glutathione peroxidase 4 (GPx4) is responsible for scaffolding toxic peroxide phospholipids and reducing neuronal death within the CNS. Therefore, screening for lead compounds able to activate this essential enzyme might protect neuronal cells from damage and slow the disease progression. This study aimed to identify potential activators of GPx4, an essential inhibitor to ferroptosis, as a novel neuroprotective strategy in MS treatment. For understanding the binding of the four selected compounds to GPX4 protein showing the mechanism of the interaction, molecular docking analysis and molecular dynamic (MD) simulation were used. The study was carried out through various computational methods using Autodock Vina for docking of the protein and ligand and Desmond for MD simulation. The four tested compounds used to activate GPx4 are as follows: ferrostatin, lapatinib, liproxstatin-1, and PKUMDL-LDL-102. Results showed that the lapatinib had greater log P value (6.17) which indicates higher permeability through blood brain barrio (BBB) to exirt the proposed neurological effect. In the molecular docking analysis, the best docking scores was displayed by Lapatinib (−7.6 kcal/mol). Ferrostatin, Lapatinib, and Liproxstatin-1 almost bind in the similar sites of the target protein, while PKUMDL-LC-102 binds at a different site. Furthermore, MD simulation study showed a stable system for lapatinib and liproxstatin-1 as confirmed by RMSD and RMSF values during 100 ns trajectories. Additionally, the most negative ΔG Bind score (the lowest) which considered the best was exhibited by lapatinib (−47.52 Kcal/mol). The test compounds were further inspected for their intersction with GPx4 in terms of hydrophobic, hydrogen and other bonding types beside the stability of these bonds by observing the protein–ligand contact within 100 ns trajectories. Interestingly, the receptor–ligand complex showed deep continuous bands for Lapatinib with Lys127 and Gly128. In conclusion, among the four studied compounds Lapatinib could be a promising scaffold for developing effective leads capable of activating GPx4 and assist in the treatment of MS

Molecular typing and antimicrobial resistance of group B Streptococcus clinical isolates in Saudi Arabia

ABSTRACT: Objectives: Group B Streptococcus (GBS) has emerged as an important cause of severe infections in adults. However, limited data are available regarding the epidemiology of GBS in Saudi Arabia. Methods: Isolates were collected over a period of eight months from colonized (n = 104) and infected adults (n = 95). Serotypes and virulence determinants were detected by polymerase chain reactions (PCRs). Genetic relatedness was assessed using Multiple Locus Variable Number Tandem Repeat Analysis (MLVA). Antimicrobial susceptibilities were determined by disk diffusion. Results: Serotypes III and V (25% each) were the most prevalent, followed by serotypes II (16.18%), Ia (13.24%), VI (9.31%), and Ib (8.82%), while five isolates remained non-typeable (2.45%). Hypervirulent serotype III/CC17 clone (n = 21) accounted for 41.18% of the serotype III isolates. Most isolates (53.92%) harboured pilus island (PI) 1 and 2a types, while PI-2b was predominantly detected in the hypervirulent clone. Isolates were variably resistant to tetracycline (76.47%), erythromycin (36.76%), clindamycin (25.49%), and levofloxacin (6.37%), but remained susceptible to penicillin. Macrolide resistant isolates exhibited constitutive (55.42%) and inducible macrolide-lincosamide-streptogramin B resistance phenotypes (33.74%), while a few had L (9.64%) or M (1.2%) phenotypes. MLVA patterns of dominant serotypes III and V revealed 40 different types divided into 12 clusters and 28 singletons. Interestingly, macrolide resistance was significantly associated with two major MLVA types. Conclusions: GBS isolates belonged predominantly to serotypes III and V, but there were no clear associations between serotypes and patient groups. The studied isolates exhibited high levels of resistance to erythromycin and clindamycin that need further surveillance

Organic acid blend supplementation increases butyrate and acetate production in Salmonella enterica serovar Typhimurium challenged broilers.

The burden of enteric pathogens in poultry is growing after the ban of antibiotic use in animal production. Organic acids gained attention as a possible alternative to antibiotics due to their antimicrobial activities, improved nutrient metabolism and performance. The current study was conducted to evaluate the effectiveness of organic acid blend on broilers cecal microbiota, histomorphometric measurements, and short-chain fatty acid production in Salmonella enterica serovar Typhimurium challenge model. Birds were divided into four treatments, including a negative control, positive control challenged with S. Typhimurium, group supplemented with an organic acid blend, and birds supplemented with organic acid blend and Salmonella challenged. Results illustrate significant differences in feed conversion ratios and production efficiency factor between treatment groups, however, the influence of organic acid supplement was marginal. Organic acid blend significantly increased cecal acetic and butyric acids concentrations when compared to unsupplemented groups and resulted in minor alterations of intestinal bacterial communities

Bacillus subtilis PB6 based probiotic supplementation plays a role in the recovery after the necrotic enteritis challenge

In poultry production, birds are raised under intensive conditions, which can enable rapid spread of infections, with Clostridium perfringens-caused necrotic enteritis (NE) being one of the most devastating for the industry. The current investigation was conducted to evaluate the effectiveness of Bacillus subtilis PB6 probiotic supplementation on bird’s post NE recovery, based on chicken performance, cecal microbiota composition, ileum histomorphometric measurements, and short-chain fatty acid production in the cecum of the birds that were challenged with NE mid-production. Birds were split into four groups, including a negative control, positive control challenged with C. perfringens, group supplemented with B. subtilis probiotic, and NE challenged birds supplemented with B. subtilis probiotic. Following NE challenge birds were allowed to reach the end of production time at 40 days, and samples were collected to estimate if probiotic supplementation resulted in better post-NE recovery. Intestinal lesion score across the duodenum, jejunum, and ileum indicated that at the end of production timeline NE challenged birds supplemented with B. subtilis probiotic had lower intestinal lesion scores compared to NE challenged birds without probiotic supplementation implying improved recovery. Probiotic supplementation improved performance of NE challenged birds only in the post-NE recovery stage. NE challenged birds had a significant increase in cecal propionic acid, which was not observed in NE challenged birds supplemented with B.subtilus. Both B. subtilis supplemented groups (challenged and unchanged) were characterized by a significant rise in cecal acetic and butyric acid. Our results demonstrate that B. subtilis supplementation can assist the birds in dealing with NE outbreak and long term recovery