Isolation, Molecular Identification and Antibacterial Potential of Marine Bacteria from Deep Atlantic Ocean of Morocco.

Background: Antibiotic resistance is an important concern for the public health authorities at global level. It is detrimental to human and environmental ecosystems, thus, there is a big need for natural bioactive compounds. In this work, we aimed to find out biomolecules derived from marine bacteria that may constitute an alternative to antibiotics. Methods: We isolated and identified thirty one marine bacteria collected from deep ocean water in central coast of Safi city, Morocco. Then, we induced biomolecules production in six marine bacterial strains. The extracts were tested for their antibacterial activity against gram-negative and gram-positive bacteria such as Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 33592 and Listeria monocytogenes ATCC 19117. Furthermore, we partially analyzed the chemical composition of these biomolecules and evaluated their sensibility to different temperatures. Results: The six marine bacteria were able to produce molecules which inhibited the three pathogenic strains with high inhibition zones reaching 27 mm. These molecules were characterized by heat stability from 60 to 121°C relying on each strain. Conclusion: The produced molecules may offer a great potential to pharmaceutical industries as they may constitute an alternative to antibiotics that are becoming less effective due to the emergence of drugs resistance.

Isolation and Identification of Dominant Bacteria from Raw Donkey Milk Produced in a Region of Morocco by QIIME 2 and Evaluation of Their Antibacterial Activity.

Recently, the interest in donkey milk has increased considerably because it proved high nutritive and functional values of their ingredients. Its chemical composition is widely studied, but its microbiota, especially lactic acid bacteria, remains less studied. This study focuses on analyzing, isolating, and identifying lactic acid bacteria and evaluating their capacity to produce biomolecules with antibacterial activity. Among 44 strains identified, 43 are Gram-positive, and most are catalase-negative and cocci-shaped. Five strains were selected to evaluate their antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli. Different induction methods allowed to amplify the antibacterial effects against these pathogenic strains.

Phylogeography of the insular populations of common octopus, Octopus vulgaris Cuvier, 1797, in the Atlantic Macaronesia.

Exploited, understudied populations of the common octopus, Octopus vulgaris Cuvier, 1797, occur in the northeastern Atlantic (NEA) throughout Macaronesia, comprising the Azores, Madeira and Canaries, and also the Cabo Verde archipelago. This octopus species, found from the intertidal to shallow continental-shelf waters, is largely sedentary, and the subject of intense, frequently unregulated fishing effort. We infer connectivity among insular populations of this octopus. Mitochondrial control region and COX1 sequence datasets reveal two highly divergent haplogroups (α and ß) at similar frequencies, with opposing clinal distributions along the sampled latitudinal range. Haplogroups have different demographic and phylogeographic patterns, with origins related to the two last glacial maxima. FST values suggest a significant differentiation for most pairwise comparisons, including insular and continental samples, from the Galicia and Morocco coasts, with the exception of pairwise comparisons for samples from Madeira and the Canaries populations. Results indicate the existence of genetically differentiated octopus populations throughout the NEA. This emphasizes the importance of regulations by autonomous regional governments of the Azores, Madeira and the Canaries, for appropriate management of insular octopus stocks.

Evolución temporal del índice gonadal de los erizos marinos Paracentrotus lividus (Echinoida: Echinidae) y Diadema africanum (Diadematoida: Diadematidae) en las islas Canarias (España) / Temporal evolution of the gonad index of the sea urchins Paracentrotus lividus (Echinoida: Echinidae) and Diadema africanum (Diadematoida: Diadematidae) in the Canary Islands (Spain)

Resumen Con el fin de establecer las épocas óptimas de explotación como posible recurso marisquero de dos especies de erizos de mar en Canarias, se estudió la evolución temporal del índice gonadal en diferentes años y localidades de Paracentrotus lividus (abril de 2006 a marzo de 2008 en la isla de Tenerife y en dos localidades: Las Galletas y La Jaca; abril de 2006 a enero de 2009 en la isla de Gran Canaria y en dos localidades: Ojos de Garza y Gando), y de Diadema africanum (de enero de 2010 a mayo de 2011 en la isla de Gran Canaria y en tres localidades: Risco Verde, Arguineguín y Agaete). En el caso de P. lividus, que se encuentra en el límite sur de su distribución, se constató la presencia de varios picos máximos anuales en el índice gonadal, probablemente relacionados con la temperatura. Estas épocas de mayor índice gonadal se correspondieron con los estados de maduración de las gónadas. La principal época de madurez coincidió con el otoño y comienzo del invierno (agosto, octubre y diciembre). Existió emisión de gametos esporádicos en el año según la localidad, en abril, en verano (junio, julio o agosto), otoño (septiembre u octubre) e invierno (diciembre, enero o febrero). Posiblemente esta situación tan dispar sea debido a la exposición al hidrodinamismo de la zona y a la presencia o no de abundante alimento. Para D. africanum se presentó el máximo índice en los meses de mayo-junio, con prácticamente pocas variaciones anuales en la localidad situada más al sur (Arguineguín). En conclusión, las dos especies de erizos serían complementarias como recursos marisqueros, ya que no se superponen sus periodos de máximos IG (época de captura) en el año.

Abstract There are three main species of regular sea urchins in the Canary Islands. To establish the optimal fishing seasons for two of them, we studied the evolution of the gonadal index in several years and locations, of Paracentrotus lividus (April 2006 to March 2008 on Tenerife island in two locations: Las Galletas and La Jaca and from April 2006 to January 2009 in Gran Canaria island in two locations: Ojos de Garza and Gando), and Diadema africanum (January 2010 to May 2011 on Gran Canaria island in three locations: Risco Verde, Arguineguin and Agaete). In the case of P. lividus, located on the southern edge of their distribution, the presence of several annual maximum gonadal indez peak was observed, probably related to the temperature. These times of gonadal index increases corresponded to the stages of maturation. The main period of maturity coincided with the fall and early winter (August, October and December). There was sporadic emissions of gametes depending on location, in April, during the summer (June, July or August), autumn (September or October) and winter (December, January or February). This fragmented situation is possibly due to exposure to the hydrodynamic area's and food abundance. The maximum presence of D. africanum occurred in the months of May to June, with virtually no variations throughout the year, in the southernmost locality (Arguineguin). In conclusion, the two species of sea urchins would be complementary shellfish resources, as their periods of maximum GI (Gonadal Index, capture time) do not overlap during the year. Rev. Biol. Trop. 63 (Suppl. 2): 251-260. Epub 2015 June 01.

Phylogeography of a Marine Insular Endemic in the Atlantic Macaronesia: The Azorean Barnacle, Megabalanus azoricus (Pilsbry, 1916).

The Azorean barnacle, Megabalanus azoricus (Pilsbry, 1916), is a Macaronesian endemic whose obscure taxonomy and the unknown relationships among forms inhabiting isolated Northern Atlantic oceanic islands is investigated by means of molecular analysis herein. Mitochondrial data from the 16S rRNA and COX1 genes support its current species status, tropical ancestry, and the taxonomic homogeneity throughout its distribution range. In contrast, at the intraspecific level and based on control region sequences, we detected an overall low level of genetic diversity and three divergent lineages. The haplogroups α and γ were sampled in the Azores, Madeira, Canary, and Cabo Verde archipelagos; whereas haplogroup ß was absent from Cabo Verde. Consequently, population analysis suggested a differentiation of the Cabo Verde population with respect to the genetically homogenous northern archipelagos generated by current oceanographic barriers. Furthermore, haplogroup α, ß, and γ demographic expansions occurred during the interglacial periods MIS5 (130 Kya - thousands years ago -), MIS3 (60 Kya), and MIS7 (240 Kya), respectively. The evolutionary origin of these lineages is related to its survival in the stable southern refugia and its demographic expansion dynamics are associated with the glacial-interglacial cycles. This phylogeographic pattern suggests the occurrence of genetic discontinuity informative to the delimitation of an informally defined biogeographic entity, Macaronesia, and its generation by processes that delineate genetic diversity of marine taxa in this area.

Development of a multiplex PCR-ELISA method for the genetic authentication of Thunnus species and Katsuwonus pelamis in food products.

In the present work a PCR-ELISA technique for the authentication of Thunnus species was developed. This method is composed by four systems that can be used in a hierarchical way allowing the identification of several scombroids species; or each individual system independently. The hierarchical strategy, proposes a first step, to assign one sample to the Thunnus genus. Next, if the result is positive, several tests can be applied to assign the sample to some particular species of the Thunnus genus. In the case that the result is negative (absence of Thunnus species), it is possible to verify if Katsuwonus pelamis is included in the sample. The method even allows the detection of mixtures of these species in relatively low amounts (up to 1%). Finally, this method was applied to 11 commercial samples to verify the labelling status of tuna products in the market, detecting that 18% were mislabelling.

Cloning and heterologous overexpression of three gap genes encoding different glyceraldehyde-3-phosphate dehydrogenases from the plant pathogenic bacterium Pseudomonas syringae pv. tomato strain DC3000.

The gammaproteobacterium Pseudomonas syringae pv. tomato DC3000 is the causal agent of bacterial speck, a common disease of tomato. The mode of infection of this pathogen is not well understood, but according to molecular biological, genomic and proteomic data it produces a number of proteins that may promote infection and draw nutrients from the plant. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a major enzyme of carbon metabolism that was reported to be a surface antigen and virulence factor in other pathogenic microorganisms, but its possible role in the infection process of P. syringae has so far not been studied. Whole-genome sequence analyses revealed the occurrence in this phytopathogenic bacterium of three paralogous gap genes encoding distinct GAPDHs, namely two class I enzymes having different molecular mass subunits and one class III bifunctional D-erythrose-4-phosphate dehydrogenase/GAPDH enzyme. By using genome bioinformatics data, as well as alignments of both DNA and deduced protein sequences, the three gap genes of P. syringae were one-step cloned with a His-Tag in pET21a vector using a PCR-based strategy, and its expression optimized in Escherichia coli BL21 to achieve high yield of the heterologous proteins. In accordance with their distinct molecular phylogenies, these bacterial gap genes encode functional GAPDHs of diverse molecular masses and nicotinamide-coenzyme specificities, suggesting specific metabolic and/or cellular roles.

Effects of amphetamine and cocaine on the development of acute experimental allergic encephalomyelitis in Lewis rats.

The present experiment deals with the effects of amphetamine and cocaine on the development and course of experimental allergic encephalomyelitis (EAE) induced in Lewis rats. Rats were immunized at the age of eight weeks with purified myelin basic protein isolated from guinea pig brain in complete Freund's adjuvant. Drug administration and recording of EAE clinical signs was performed daily since day 1 post-immunization (PI). On day 14 and 28 PI, six rats per group were bled and sacrificed. Spinal cord was examined histologically for EAE lesions. In vivo administration of 0.5 and 1 mg/Kg of amphetamine or cocaine resulted in a dose-related enhancement of neurological and histological signs of acute EAE in comparison with control rats. Both drugs caused a reduction of latent period together with a delayed regression of neurological signs along with an increase in inflammation in the central nervous system in comparison with placebo. Human & Experimental Toxicology (2007) 26, 637-643.

Effects of nefazodone on the development of experimentally induced tumors in stressed rodents.

RATIONALE: Anxiety and depression are commonly encountered in patients with cancer and constitute risk and prognostic factors for the disease. Although previous findings do not support an overall association between the use of antidepressants and higher prevalence of cancer, results for serotonin uptake inhibitors are not entirely reassuring. OBJECTIVES: We evaluated the effects of nefazodone, a serotonin and norepinephrine (NE) reuptake inhibitor and 5-HT(2A) receptor antagonist antidepressant, on the appearance of breast cancer induced by mammary tumor virus (MTV) in mice, and on the development of lung metastases in rats injected intravenously with Walker 256 (W-256) carcinosarcoma cells. METHODS: Female C3H/He mice carrying the MTV were monitored for mammary tumor incidence and latent periods while being treated with a daily intraperitoneal injection with placebo or nefazodone. Rats were administered 10(4) W-256 cells, exposed to a chronic auditory stressor for 8 days, and then killed to evaluate metastatic nodules in the lungs. RESULTS: Although all of the mice were potential candidates for MTV-induced breast cancer, those treated with nefazodone were partially protected against adverse effects of stress induced by the daily administration of placebo on both parameters. Relative to placebo, nefazodone reduced the stress-induced increase in the number and percentage area of metastases in the frontal section through pulmonary hilus and increased the survival periods of rats given W-256 cells and exposed to a chronic auditory stressor. CONCLUSIONS: Our results provide evidence of the beneficial effects of nefazodone against the adverse effects of stress on tumor development and metastaticity in rodents, but did not show significant effects in unstressed rodents.

Evolution of the thymus size in response to physiological and random events throughout life.

During embryogenesis and in the early stages of life, the thymus is a crucial organ for the generation of the T cell repertoire. T cells are generated from hematopoietic stem cells already differentiated to precursor T cells in the bone marrow. These cells enter the thymus guided by chemotactic factors secreted by this organ. The complex maturation process takes place that ensures self-tolerance and homeostasis. Thymocytes that show autoreactivity do not leave the thymus, but rather die by apoptosis. The final percentage of mature T cells that survive to migrate from the thymus to the periphery is very low: at most 5%, under optimal conditions. The highest migration occurs in childhood and adulthood, at least in mice and humans; however, it declines throughout life and is minimal in the elderly. Under normal circumstances, the thymus commences involution soon after birth, and this involution correlates with the capacity to export mature T cells to the periphery. Hormones, cytokines, and neurotransmitters all play a role in this age-associated process, but the reasons for and mechanisms of this involution remain unknown. Apart from physiological conditions that change throughout life and govern age-related thymus evolution, random states and events provoked by intrinsic or extrinsic factors can induce either thymus involution, as in reversible transient thymic hypoplasias, or thymic hyperplasias. The age-associated involution, unlike transient involutions, follows a regular pattern for all individuals, though there are clear differences between the sexes. Nevertheless, even the age-associated involution seems to be reversible, raising the possibility of therapeutic strategies aimed at enhancing thymus function in the elderly.

Administration of the 5-hydroxytryptamine(1A) receptor antagonist WAY100635 suppresses acute experimental allergic encephalomyelitis in Lewis rats.

Experimental allergic encephalomyelitis (EAE) is a T-cell inflammatory disease of the central nervous system (CNS) widely considered as an animal model of multiple sclerosis. In Lewis rats, myelin basic protein-complete Freund's adjuvant (MBP-CFA)-induced EAE is an acute monophasic disease from which animals recover fully. In our experiments, daily treatment (since day 1 after MBP-CFA inoculation) with the 5-hydroxytryptamine((1A)) (5-HT(1A)) receptor agonist (R)-(+)-8-hydroxy-2-(Dipropylamino)-tetralin (R(+)-8-OH-DPAT) resulted in a dose-related enhancement of neurological and histological signs in EAE-induced rats. This effect of R(+)-8-OH-DPAT was reduced by the co-administration of the 5-HT(1A) receptor antagonist (N-[2-(4-[2-mehoxyphenil]-1-piperazinyl)-ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY100635) at the peak of the acute disease. Moreover, treatment with WAY100635 since inoculation resulted in a delayed onset of the first clinical signs, milder disease and earlier regression of neurological signs along with a decrease in inflammation in the CNS.

Effects of fluoxetine on the activity of phagocytosis in stressed mice.

We studied the effects of 1, 2, 5, 10 and 20 mg/kg of fluoxetine on the activity of phagocytosis in mice subjected to a chronic auditory stressor. Both the in vitro and in vivo activity of phagocytosis, measured using the zymosan-particle uptake method and the carbon clearance test, respectively, were reduced after 2, 4, 8 and 16 days of stress exposure. A partial recovery on the in vivo activity of phagocytosis was found on day 16th. Daily treatment with fluoxetine partially reversed the adverse effects of stress in a dose-dependent manner on both parameters but did not significantly affect the activity of phagocytosis in unstressed mice. Significant differences appeared when fluoxetine was administered at 2 mg/kg. Maximum effect was reached at 5 mg/kg.

Effects of nefazodone on voluntary ethanol consumption induced by isolation stress in young and aged rats.

Late-onset ethanol (EtOH) consumption is related to life and social stressors of aging. The stress system (hypothalamic-pituitary-adrenal, HPA, axis) coordinates the adaptive response of the organism to stressors, but age-related deficits in HPA function seem to be associated with disorders such as late-onset EtOH consumption, anxiety and depression. In the present study, we examined whether HPA dysfunction is associated with stress-related EtOH consumption in aged rats and whether the treatment with nefazodone hydrochloride, a phenylpiperazine antidepressant, partially reverses the adverse effects of isolation (ISOL) stress. The animals were offered two-bottle choice consumption of 0.2% saccharin and 10% EtOH/0.2% saccharin, and then exposed to 4 days of ISOL stress on an irregular, unpredictable schedule. ISOL stress-induced increases in corticosterone secretion and EtOH consumption both during and following the stress (recovery period) in aged rats. Nevertheless, this effect at the recovery period was not evident in young stressed rats. Nefazodone caused a significant decrease in plasma corticosterone levels and EtOH consumption. The attenuation of stress-induced corticosterone by nefazodone was correlated with reduced EtOH consumption. These findings link the effect of ISOL stress to the induction of voluntary EtOH consumption following the end of the stressor and the limitation of aged HPA to down-regulated corticosterone.