Leptospirosis, caused by the pathogenic leptospires, is one of the most widespread zoonotic diseases known. Leptospirosis cases can occur either sporadically or in epidemics, Humans are susceptible to infection by a variety of serovars. These bacteria are antigenically diverse. Changes in the antigenic composition of lipopolysaccharide (LPS) are thought to account for this antigenic diversity. The presence of more than 200 recognized antigenic types (termed serovars) of pathogenic leptospires have complicated our understanding of this genus. Definitive diagnosis is suggested by isolation of the organism by culture or a positive result on the microscopic agglutination test (MAT). Only specialized laboratories perform serologic tests; hence, the decision to treat should not be delayed while waiting for the test results.

The purpose of this work was to screen clinical isolates of actinomycetes producing nonpolyenic antifungals. This choice was made to limit the problem of rediscovery of well-known antifungal families, especially polyenic antifungals. One hundred and ten strains were tested, using two diffusion methods and two test media, against three yeast species and three filamentous fungi. Among 54 strains (49%) showing antifungal activity, five strains belonging to the genus Streptomyces were active against all test organisms and appeared promising. These results indicate that clinical and environmental isolates of actinomycetes could be an interesting source of antifungal bioactive substances. The production of nonpolyenic antifungal substances by these five active isolates was investigated using several criteria: antibacterial activity, ergosterol inhibition, and UV-visible spectra of active extracts. One active strain responded to all three selection criteria and produced potentially nonpolyenic antifungal metabolites. This strain was retained for further investigation, in particular, purification, structure elucidation, and mechanism of action of the active product.

Diarrheic shellfish poisoning (DSP) is a recurrent gastrointestinal illness in Morocco, resulting from consumption of contaminated shellfish. In order to develop a rapid and reliable technique for toxins detection, we have compared the results obtained by a commercial immunoassay-"DSP-Check" kit" with those obtained by LC-MS. Both techniques are capable of detecting the toxins in the whole flesh extract which was subjected to prior alkaline hydrolysis in order to detect simultaneously the esterified and non esterified toxin forms. The LC-MS method was found to be able to detect a high level of okadaic acid (OA), low level of dinophysistoxin-2 (DTX2), and surprisingly, traces of azaspiracids 2 (AZA2) in mussels. This is the first report of a survey carried out for azaspiracid (AZP) contamination of shellfish harvested in the coastal areas of Morocco. The "DSP-Check" kit was found to detect quantitatively DSP toxins in all contaminated samples containing only OA, provided that the parent toxins were within the range of detection and was not in an ester form. A good correlation was observed between the two methods when appropriate dilutions were performed. The immunoassay kit appeared to be more sensitive, specific and faster than LC-MS for determination of DSP in total shellfish extract.

(-)-Untenospongin B isolated from the marine sponge Hippospongia communis has been tested for its antimicrobial activity against bacteria and human pathogenic fungi using agar disk method and was found to possess a broad and strong activity toward the test organisms. Its antifungal activity was further characterized by determination of the minimum inhibitory concentration (MIC) against five fungal species using broth microdilution method.

Electrochemical regeneration of NAD was performed at a laboratory preparative scale to illustrate both the efficiency and intrinsic simplicity of the electrochemical method. A powerful plug-flow reactor was realized with a flow through graphite felt electrode, the ratio of the effective area of electrode/volume of reactor increased to 380 cm(2)/cm(3). This graphite-felt electrode was able to oxidize NADH coenzyme at a very low overvoltage. On the example of the gluconic acid production catalyzed by glucose dehydrogenase, current as high as 0.1 A was obtained in experience where enzymatic activity was the main limitation. In confirmation of our previous work, the results show that the yield of NADH electrochemical oxidation is better than 99.95%.

In the aim of searching for new antifungal products from marine origin, we have isolated a sphingosine derivative, (9Z)-2-amino-docos-9-ene-1,3,13,14-tetraol (Haliscosamine) from the Moroccan sea sponge Haliclona viscosa using bio-guided (antifungal) HPLC methods. The molecular structure of this compound was elucidated by spectrometric techniques IR, UV, MS and NMR. The isolated metabolite showed a significant antifungal activity against Cryptococcus and Candida species and a weak general toxicity in the brine shrimp lethality test. Further research is needed to study its in vivo activity, as well as to elucidate the mechanism underlying its activity in the hope of a future use in medical mycology.

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The alkaloid harman, previously reported from some marine invertebrates, was identified as the antibiotic substance of the tunicate-associated bacterium Enterococcus faecium. It exhibited antibacterial activity (MIC, 0.017 mM) against the ichthyopathogenic strain Vibrio anguillarum.