Cyanobacterial mats of the Arabian Gulf coast of Saudi Arabia experience extreme conditions of temperature and salinity. Because they are exposed to continuous oil pollution, they form ideal models for biodegradation under extreme conditions. We investigated the bacterial diversity of these mats using denaturing gradient gel electrophoresis and 16S rRNA cloning, and tested their potential to degrade petroleum compounds at various salinities (fresh water to 16%) and temperatures (5 to 50 degrees C). Cloning revealed that c. 15% of the obtained sequences were related to unknown, possibly novel bacteria. Bacteria belonging to Beta-, Gamma- and Deltaproteobacteria, Cytophaga-Flavobacterium-Bacteroides group and Spirochetes, were detected. The biodegradation of petroleum compounds at different salinities by mat microorganisms showed that pristine and n-octadecane were optimally degraded at salinities between 5 and 12% (weight per volume NaCl) whereas the optimum degradation of phenanthrene and dibenzothiophene was at 3.5% salinity. The latter compounds were also degradable at 8% salinity. The same compounds were degraded at temperatures between 15 and 40 degrees C but not at 5 and 50 degrees C. The optimum temperature of degradation was 28-40 degrees C for both aliphatics and aromatics. We conclude that the studied microbial mats from Saudi Arabia are rich in novel halotolerant and thermotolerant microorganisms with the potential to degrade petroleum compounds at elevated salinities and temperatures.

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This study aims to determine the effect of climatic factors (temperature, relative humidity and rainfall) on mosquito abundance and to map mosquito larva breeding sites using GIS application in Eastern Province, Saudi Arabia. The data pertaining to larval and adult mosquito abundance/distribution and climatic factors were collected for the study period of 2014. Bi-variate and multivariate analyses were performed to determine the relationship between mosquito abundance and climatic factors (temperature, relative humidity and rainfall). The utilization of GIS with GPS facilitates to identify and map larva breeding sites in the study area. The result showed strong negative correlation between mosquito abundance and temperature while there appeared a strong positive correlation with relative humidity and moderate positive correlation with rainfall. Low mosquito abundance was observed at high temperatures whereas high and moderate mosquito abundance was observed at high humidity and during rainy months, respectively. In the adult mosquito, the regression model for three climatic factors (temperature, RH and rainfall) and other factors showed a variation of 84.5% of the variance accounted for the climatic factors while the remaining 15.5% were attributed to other factors. In larva, 64.3% of the variance accounted for climatic factors, and the remaining 35.7% attributed to other factors such as the presence of vegetation, waste materials and water reservoirs such as ditches. In comparison, the larva seems influenced by the presence of vegetation, waste material, water reservoirs and ditches and less influenced by climatic factors than the adult mosquito. Development of a risk map by considering the flying distance of the adult mosquito from the studied sites showed three major clusters where a recommendation for management control program was suggested.

Coartem w , the combination of artemether (an artemisinin derivative) and lumefantrine, has been adopted as the first-line treatment for uncomplicated malaria in many countries. The emergence of resistance to artemisinin derivatives has now been proven in South-East Asia, and there is concern that this may spread to other endemic areas. Strategies to contain and control the spread of artemisinin resistance have been proposed. On the other hand, not much attention has been given to lumefantrine. Indeed, for more than 7 years, reports have been emerging that the use of Coartem w is associated with rapid selection of lumefantrine-tolerant parasites. These parasites can survive in the presence of sub-therapeutic lumefantrine concentrations, and, interestingly, this in vivo phenotype is translated in vitro into reduced susceptibility to lumefantrine. As a result, such parasites could form the setting in which lumefantrine resistance would emerge. Thus, identifying genetic markers that reflect this phenotype (both in vitro and in vivo) could yield information on the mechanisms of lumefantrine resistance. More interestingly, lumefantrine tolerance is associated with an increase in chloroquine susceptibility, raising the possibility of re-introducing chloroquine. In this work, we have reviewed the current knowledge, and we present existing challenges and gaps with regard to the mechanisms of in vivo tolerance and in vitro reduced susceptibility to lumefantrine. The re-introduction of chloroquine in areas of high lumefantrine resistance is also discussed.

A new species of endolithic cyanobacteria, Hyella racemus sp. nov. (order Pleurocapsales), penetrates ooid grains in actively shoaling sands in shallow (0.5–5 m) waters of the Bahama carbonate platform and the Arabian Gulf. Hyella racemus is characterized by prolific branching, resulting in dense grape‐like cell clusters that penetrate the carbonate substrate. The clusters radiate inward and form deep, isodiametric pits. Resin casts of these pits are framboid (raspberry‐like) in shape. The borehole morphology conforms with the shape of the endolith body and can be identified in resin‐cast preparations. Cell division is by cleavage with regular alternation of division planes. The sheath is tight, layered, and colorless or yellow‐brown when under strong illumination. The new species is one of the most common endoliths in ooids of the Bahamas and the Arabian Gulf It differs from other members of this endolithic genus by its branching pattern and less prominent apical cells.