Rehab Mohamed Atta El-Desoukey

Stipagrostis plumosa is a desert grass that remains relatively underexplored with respect to its phytochemical composition and biological activities, particularly against pathogens of veterinary relevance. This study aimed to characterize the phytochemical profile of S. plumosa and evaluate the antioxidant, antimicrobial, and cytotoxic activities of its extracts and solvent fractions. Aerial parts of S. plumosa were collected during the flowering season from Al-Quwai’iyah, Saudi Arabia, and subjected to methanolic extraction followed by solvent fractionation. Total phenolic and flavonoid contents, antioxidant activity, antimicrobial activity against bacterial and fungal strains, and cytotoxicity against MCF-7 and A549 cells were evaluated. GC–MS was used to characterize the ethyl acetate and chloroform fractions. The crude methanolic extract contained 72.1 mg GAE/g extract of total phenolics and 13.6 mg QE/g extract of total flavonoids. The ethyl acetate fraction exhibited the strongest antioxidant activity (IC₅₀ = 72.48 µg/mL) and the most pronounced antimicrobial activity, whereas the chloroform fraction showed the highest cytotoxic activity against MCF-7 and A549 cells, with IC₅₀ values of 173.52 and 194.17 µg/mL, respectively. GC–MS profiling revealed diverse phenolic derivatives, fatty acids and their esters, oxygenated compounds, and phytosterol-related constituents. Stigmasta-3,5-dien-7-one (14.70%) and vanillic acid (7.18%) predominated in the ethyl acetate fraction, while hexadecanoic acid methyl ester (5.28%) was among the major constituents of the chloroform fraction. Overall, the fraction-dependent biological activities and diverse phytochemical profiles highlight S. plumosa as a promising source of natural bioactive compounds with potential relevance to veterinary health and the development of alternative antimicrobial strategies.

Serratia marcescens is a nosocomial pathogen that has acquired resistance to multiple antibiotics, necessitating alternative antimicrobial strategies. The aim of this study was to isolate and characterize a novel phage (ØAS2) against Serratia marcescens and evaluate its biocontrol potential in dairy matrices. In this study, a lytic bacteriophage specific to S. marcescens, designated ØAS2, was isolated from sewage samples collected in Assiut, Egypt. Phage ØAS2 was characterized using plaque assays, transmission electron microscopy (TEM), host range determination, pH and thermal stability tests, and one-step growth curve analysis. Its ability to inhibit bacterial growth and disrupt biofilms was also evaluated in vitro. TEM revealed that ØAS2 possesses an icosahedral head approximately 47.2 nm in diameter and a very short tail, consistent with the morphology of a member of the class Caudoviricetes that exhibits podovirus-like morphology. The phage exhibited a broad host range, infecting various Serratia strains as well as other Gram-negative bacteria, including Klebsiella spp., Escherichia coli, Salmonella typhi, and Shigella spp. ØAS2 was thermostable up to 60 °C and showed maximum activity at pH 8. One-step growth curve analysis revealed a short latent period of 10 min and a burst size of 115 PFU per infected cell. ØAS2 effectively inhibited the growth of S. marcescens SM02 in vitro and significantly reduced preformed biofilms at different multiplicities of infection (MOIs). When applied to skim milk and fresh soft cheese at various MOIs (Multiplicities of Infection), the phage successfully controlled bacterial contamination under refrigerated storage (7 °C for 7–10 days). At MOI 5.0, phage ØAS2 reduced biofilm biomass by 25.6%, planktonic growth by 85.7%, and achieved a reduction of 2.1 log₁₀ CFU/mL in skim milk. These findings indicate that ØAS2 is a promising biocontrol candidate for managing S. marcescens spoilage in dairy products.

The growing issue of antimicrobial resistance poses a significant challenge for microbiological research, driving the need for alternative antibiotics with minimal side effects. Zygophyllum coccineum, commonly referred to as “Tebtab” in Arabic and “Red Spinepod” in English, has traditionally been utilized as forage for camels and ruminants. While its antimicrobial activity against human pathogens has been documented, its efficacy against animal pathogens remains underexplored. This study aims to evaluate the phytochemical composition, biological activities, and antimicrobial potential of water and organic-solvent extracts of Zygophyllum coccineum against a range of reference microbial strains and animal pathogens. The findings revealed that all extracts exhibited notable antimicrobial, antioxidant, and cytotoxic activities attributed to their bioactive constituents. Among them, the ethyl acetate extract displayed the strongest antimicrobial effects against bacterial and fungal strains. Additionally, this extract demonstrated the highest antioxidant capacity and showed promising cytotoxic activity against lung (A549) and breast (MCF-7) cancer cell lines. These results underscore the potential of Zygophyllum coccineum as a valuable natural resource for developing antimicrobial, antioxidant, and cytotoxic therapies for applications in both human and veterinary medicine.

Due to the global issue of antimicrobial resistance, one of the most significant challenges in microbiological research is to develop a replacement antibiotic with minimal adverse effects. The wild shrub Pulicaria crispa (gethgath) has been traditionally used for camel and ruminant grazing. While prior research has demonstrated its antimicrobial properties against human diseases, no investigations have been conducted on its efficacy against animal pathogens. The objective of this study is to explore the ethnobotanical, phytochemical, antioxidant, anticancer, and antimicrobial activity of Pulicaria crispa aqueous and solvent extracts against a range of standard and animal pathogens. All of the extracts demonstrated antimicrobial, antioxidant, and anticancer properties, containing bioactive compounds. Notably, the ethyl acetate extract of P. crispa exhibited the strongest antimicrobial activity against tested Gram-positive and Gram-negative bacteria and fungi. The chloroform fraction displayed the highest antioxidant activity. Additionally, the ethyl acetate fraction showed promising anticancer activity against breast (MCF-7) and lung (A549) cancer cells. These findings confirm that Pulicaria crispa is a valuable shrub with potential applications as a natural alternative for antimicrobial, antioxidant, and anticancer treatments in both human and veterinary medicine.

| Since the beginning of human civilization many herbs have so far been used for the treatment and management of various ailments. Spreading of bacterial resistance against antibiotics is consider one of the common problems in the medical world, so one of the most important steps in microbiological researches is to find a new antimicrobial compound with minimal side effects. One of wild herbs was Acacia ehrenbergiana Hayne commonly known as Salam , which was used as animal grazing herb especially camels, sheep and goat. Due to that it seems that this plant may contain considerable antimicrobial capacity. So the aim of this study is to investigate the antimicrobial activity of Acacia ehrenbergiana Hayne aqueous extracts on some medically important animal pathogens and to determine some phytochemical compounds. Hot and cold aqueous extract of Acacia ehrenbergiana Hayne were evaluated for their antimicrobial activity against some medically important pathogens isolated from animals and poultry farms ( Staphylococcus epidermis, Escherichia coli, Streptococcus pyogens, Pseudomonas aerogenes, Salmonella typhimurium, Enterococcus, Bacillus cereus, Klebsiella pneumoniae and Candida albicans) by agar well diffusion method. Both hot and cold aqueous extract showed high antibacterial effect against the all examined pathogenic bacteria samples. While the extracts did not show any significant antifungal activity against Candida albicans. Also, phytochemical compoud of aqueous extract was determined, results of the chemical tests explain the extracts of Acacia ehrenbergiana Hayne contain alkaloids, flavnoids, tannins and saponin compounds. So it could be concluded that the Acacia ehrenbergiana Hayne extract possess remarkable antibacterial activity against gram positive and gram negative bacteria and to be introduced as an alternative to chemical antimicrobial drugs, is required wider investigation.