The Effect of Alterations in Water Quality Parameters on the Occurrence of Bacterial Diseases in Different Aquatic Environments

Abstract

The current study investigated the influence of adverse water quality parameters in different localities (Qarun Lake, Fayoum Province, Egypt; Mariotteya stream, Giza Governorate, Egypt; and Mediterranean coastal water, Alexandria Governorate, Egypt) on different fish species during the winter. Water and fish samples were collected to evaluate the physicochemical properties and heavy metal distribution in the water. Furthermore, bacteriological analysis of water and fish was performed. The physicochemical characteristics of water samples revealed high conductivity, alkalinity, and higher values of water hardness in Lake Qarun, Fayoum province and Mediterranean coastal water, Alexandria Governorate. However, the parameters in Mariotteya water were within normal limits. Heavy metals were detected in Lake Qarun and the Mediterranean Coast. However, none of the heavy metals analyzed were found in the Mariotteya water samples. Moreover, detected trace elements, cadmium and lead, exceeded the permissible limits. The bacterial load of the collected water samples revealed only the isolation of Escherichia coli and other coliform bacteria from Lake Qarun, while other bacteria included Vibrio spp. (2.48 log10 CFU/mL), Aeromonas spp. (2.70 log10 CFU/mL), and Pseudomonas spp. (3.18, 2.04 log10 CFU/mL) isolated from Lake Qarun and Mariotteya stream, and Staphylococcus spp. (2.00, 1.95, and 1.00 log10 CFU/mL) from Mariotteya stream, Lake Qarun, and Mediterranean Coast, respectively. Among the isolated bacteria from collected fishes, Aeromonas spp. weres detectable at a higher percentage (36.2%) followed by Vibrio spp. (31.4%), Pseudomonas spp. (16.2%), and Staphylococcus spp. (6.7%). Moreover, the highest percentage of bacterial isolates was recovered from Lake Qarun. Large shrimps from the Mediterranean Coast showed a high percentage of Vibrio spp. (40%) isolation. The log of viable microbial count and chemical parameters in water bodies had a strong correlation coefficient (r > 0.75), suggesting that the ecosystem is highly polluted by agricultural and industrial contamination .