Screening of antimicrobial activity of macroalgae extracts from the Moroccan Atlantic coast.

The aim of this work is the screening of the antimicrobial activity of seaweed extracts against pathogenic bacteria and yeasts. The antimicrobial activity of the dichloromethane and ethanol extracts of ten marine macroalgae collected from the Moroccan's Atlantic coast (El-Jadida) was tested against two Gram+ (Bacillus subtilis and Staphylococcus aureus) and two Gram- (Escherichia coli and Pseudomonas aeruginosa) human pathogenic bacteria, and against two pathogenic yeasts (Candida albicans and Cryptococcus neoformans) using the agar disk-diffusion method. Seven algae (70%) of ten seaweeds are active against at least one pathogenic microorganisms studied. Five (50%) are active against the two studied yeast with an inhibition diameter greater than 15 mm for Cystoseira brachycarpa. Six (60%) seaweeds are active against at least one studied bacteria with five (50%) algae exhibiting antibacterial inhibition diameter greater than 15 mm. Cystoseira brachycarpa, Cystoseira compressa, Fucus vesiculosus, and Gelidium sesquipedale have a better antimicrobial activity with a broad spectrum antimicrobial and are a potential source of antimicrobial compounds and can be subject of isolation of the natural antimicrobials.

Anti-Candida and anti-Cryptococcus antifungal produced by marine microorganisms.

In order to search for antifungal from biological origin, we performed a screening of marine microorganisms isolated from seawater, seaweed, sediment and marine invertebrates collected from different coastal areas of the Moroccan Atlantic Ocean. The antifungal activities of these isolates were investigated against the pathogenic yeasts involved in medical mycology. Whole cultures of 34 marine microorganisms were screened for antifungal activities using the method of agar diffusion against four yeasts. The results showed that among the 34 isolates studied, 13 (38%) strains have antifungal activity against at least one out of four yeast species, 11 isolates have anti-Candida albicans CIP 48.72 activity, 12 isolates have anti-C. albicans CIP 884.65 activity, 13 isolates have anti-Cryptococcus neoformans activity and only 6 isolates are actives against Candida tropicalis R2 resistant to nystatin and amphotericin B. Nine isolates showed strong fungicidal activity. Fourteen microorganisms were identified and assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea, and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms could produce more antimicrobials; therefore these marine microorganisms were expected to be potential resources of natural products such as those we research: anti-Candida and anti-Cryptococcus fungicides.

Antifungal and antibacterial activity of marine microorganisms.

In order to explore marine microorganisms with pharmaceutical potential, marine bacteria, collected from different coastal areas of the Moroccan Atlantic Ocean, were previously isolated from seawater, sediment, marine invertebrates and seaweeds. The antimicrobial activities of these microorganisms were investigated against the pathogens involved in human pathologies. Whole cultures of 34 marine microorganisms were screened for antimicrobial activities using the method of agar diffusion against three Gram-positive bacteria, two Gram-negative bacteria, and against yeast. The results showed that among the 34 isolates studied, 28 (82%) strains have antimicrobial activity against at least one pathogen studied, 11 (32%) strains have antifungal activity and 24 (76%) strains are active against Gram-positive bacteria, while 21 (62%) strains are active against Gram-negative bacteria. Among isolates having antimicrobial activity, 14 were identified and were assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms can produce antibiotic substance; therefore, these marine microorganisms were expected to be potential resources of natural antibiotic products.

[Bio-guided isolation of an antifungal from Haliclona enamela collected from Jorf Lasfar port, Morocco]. / Isolement bio-dirigé d'un antifongique à partir de Haliclona enamela récoltée du port de Jorf Lasfar, Maroc.

In the context of our search for new biologically active secondary metabolites from marine invertebrates, we have isolated an antifungal from Haliclona enamela collected from Jorf Lasfar Port, El Jadida, Morocco. This has a strong antifungal activity against three yeasts (two Candida spp. and one Cryptococcus spp.) involved in human mycology and especially against Candida tropicalis resistant to nystatin and amphotericin B.

[Seasonal and geographical variation range of antifungal activity of sponge extracts from the Moroccan Atlantic coasts]. / Variation saisonnière et géographique de l'activité antifongique des extraits de deux éponges marines récoltées sur le littoral atlantique d'El Jadida, Maroc.

Currently, marine organisms have a very important source of new molecules in pharmacology and thus in the development of new bioactive products. The organic and aqueous extracts of two marine sponges, Cinachyrella tarentine collected during two different seasons, winter and summer, and Cliona viridis collected in two different zones on the coast of El Jadida (Morocco) were tested for their antifungal activity using the diffusion method. The C. tarentine sponge collected in January (winter) has a very important activity compared to that collected in August (summer). While the sponge C. viridis collected from Jorf Lasfar port (shallower and polluted area) has a very important activity compared to that collected from the coast of El Jadida (depth and unpolluted area).