Microbial pollution indicators along the Egyptian coastal waters of Suez and Aqaba Gulfs and Red Sea.

BACKGROUND: Nowadays, the Egyptian coasts of the Aqaba and Suez Gulfs, and the Red Sea proper, are under the direct effects of many recreational resorts, urban agglomeration, marine shipping, activity of the phosphate industry, fishing ports, and limited freshwater and sewage surfaces. Therefore, the water, especially those used for recreational activities, must be of a very good quality to be able to increase the national income. OBJECTIVES: To investigate the conventional water-quality bacteria, total coliforms (TC), Escherichia coli (EC), and fecal streptococci (FS), in the Egyptian coastal waters of Suez and Aqaba Gulfs and the Red Sea. MATERIALS AND METHODS: A total of 2372 surface water samples were collected from 42 sampling sites during 12 years (1998-2009) to detect and estimate TC, EC, and FS using the membrane filtration method. RESULTS: On the basis of the national and international bacterial standards, 540 samples (22.8%) out of 2372 were found to exceed the guide values (positive samples) and were not accepted for marine recreational purposes. During the course of the study, Suez Gulf showed the highest positive records of 54 and 96 for TC and EC, respectively, whereas FS recorded 94 and 88 positive samples in the Red Sea and Suez Gulf, respectively. The lowest positive records were found in 1998 and 2009, whereas the highest were in 2000 and 2002-2004. The highest polluted sampling sites were recorded in Su7 (Suez Gulf), Aq2 (Aqaba Gulf), and Re15 (Red Sea), and were generally affected by sewage disposal and/or anthropogenic influences. CONCLUSION AND RECOMMENDATIONS: The most polluted sites were in the Suez Gulf, reaching 238 sites, followed by 194 sites in the Red Sea, whereas the Aqaba Gulf had only 108 polluted sites. Moreover, the most polluted sample locations throughout the study were Su7, Aq2, and Re15, without implementation of corrective actions from authorized organizations. The data of the current study must be taken into consideration by the government for a safer and cleaner seawater in the eastern Egyptian coasts, especially those in which critical limitations in terms of microbial pollution are found.

Listeria spp. in the coastal environment of the Aqaba Gulf, Suez Gulf and the Red Sea.

Listeria monocytogenes is an important pathogen which causes an infection called listeriosis. Because of the high mortality rate (~30%) associated with listeriosis, and the widespread nature of the organism, it is a major concern for food and water microbiologists since it has been isolated from various types of foods, including seafood, as well as from the aqueous environment. To investigate the prevalence of this pathogen in the Aqaba Gulf (12 sites), Suez Gulf (14 sites) and Red Sea (14 sites), 200 water samples (collected during five sampling cruises in 2004), 40 fresh fish samples and 15 shellfish samples were analysed using the enrichment procedure and selective agar medium. All water samples were also examined for the presence Listeria innocua which was the most common of the Listeria spp. isolated, followed by L. monocytogenes, with a low incidence of the other species. During the whole year, the percentage of Listeria spp. and L. monocytogenes in 200 water samples was 20.5% (41 samples) and 13% (26 samples) respectively. In fresh fish (40 samples) it was 37% (15 samples) and 17.3% (7 samples) and in shellfish (15 samples) 53% (8 samples) and 33% (5 samples) respectively. In water samples, there was an association between the faecal contamination parameters and the presence of the pathogen; however, water salinity, temperature, dissolved oxygen and pH did not influence the occurrence of this bacterium. These results may help in the water-quality evaluation of the coastal environments of these regions.