Microbial infections cause complicated health influences along with bad economic impacts. In the present investigation, three dominant seaweeds namely, Amphiroa anceps, Corallina officinalis and Sargassum filipendula were collected from different Egyptian sites at the Red Sea and Mediterranean Sea during autumn 2019. Organic extracts of the three algae were screened for their antibacterial activity against three pathogenic bacteria Salmonella typhiimurium, Staphylococcus aureus and Escherichia coli, in addition to in vitro antiviral activity against Rotavirus (RV), and Coxsackie virus B3 (CVB3) that cause severe diseases in human. Organic extract of A. anceps, C. officinalis and S. filipendula inhibit E. coli cells by 57.1%, 85.7%, and 91.4%, respectively. The highest level of concentration of the C. officinalis extract (100 µg/mL) inhibits 100% of Staphylococcus aureus cells followed by S. filipendula and A. anceps extract which inhibit 82.5% and 75% of S. aureus. Similarly, the highest concentration of C. officinalis extract inhibits S. typhiimurium by 80%. The extract of A. anceps exhibited a high antiviral effect against RV infection with TI = 22 and virus titers lessened by 2.75 log TCID 50 followed by extractions of C. officinalis with TI = 18.3 and virus titers reduced by 2.5 log TCID 50 . Against CVB3 infection, the extract of A. anceps causes the highest antiviral activity with TI = 15 and reduce the viral titers by 2.5 log TCID 50 , followed by extractions of C. officinalis with TI = 8.8 and inhibition of virus titers by 1.75 log TCID 50 . Extract of S. filipendula displayed the lowest antiviral effects against RV and CVB3 infection with TI = 2.4 and 1.4, respectively. The obtained results clarified that the extract of three marine seaweeds maintains a potent antimicrobial activity, making them a future promising source of new antimicrobial drugs.

Performance of BACTEC 9120 blood culture system was compared with the conventional (manual) broth method in detecting blood cultures of 500 patients suffering from various diseases. The BACTEC system proved to be superior in both yield and speed of detection. Four species of yeasts belonging to 2 genera and 13 species of bacteria belonging to 12 genera were recovered from the patient's blood cultures. The study confirmed the serious role of yeasts present in patient blood, and highlighted the serious pathological effect of their secondary metabolites, including clinical symptoms ending with death, besides the changes in the histological pattern in the internal organs, as liver, kidney and spleen using mice as an experimental animal model.