Browsing by Author "M. Ezzat, Safaa"

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An approach using a novel phage mix for detecting Pseudomonas aeruginosa in water
(Water and Environment Journal, 2019) M. Ezzat, Safaa; Ibrahim Azzam, Mohamed
The present study aims to integrate the benefits of plaque assay using a novel phage mix with phylogenetic and molecular analysis for detecting Pseudomonas aeruginosa in water. Three phages were isolated and the transmission electron microscope related their morphological resemblance to those of Siphoviridae and Podoviridae families, while molecular analysis showed different cp-gene sizes. The Phage mix was highly specific (86.0%), and data misleading didn’t exceed 14.0% compared to membrane filter assay (39.2%). Time elapsed for test completion required 24 h. Identified P. aeruginosa were verified using 16S-rDNA. Nucleotide sequence data for both phages and bacteria were submitted to the NCBI GenBank database, USA and gained their accession numbers. Concluding remarks highlight the potential of plaque assay as specific, simple and rapid method. The study recommended future efforts to isolate and characterize new phages for detecting other bacterial pathogens of public health concern to control water pollution and maintain adequate hygiene.
An Approach Using Non-Conventional Indicators for Detecting Microbial Water Pollution
(Clean - Soil, Air, Water, 2014) M. Ezzat, Safaa
The present study aims to investigate the suitability of the genus Aeromonas as a nonconventional microbial indicator of water quality in different Egyptian water resources; River Nile, drainage wastewater, and chlorinated drinking water. Aeromonas was detected in 71.2% of examined samples, being maximum in drainage water and minimum in River Nile and drinking water. Several positive significant relationships between Aeromonas and the corresponding heterotrophic plate count, total coliforms, fecal coliforms, and fecal streptococci were recorded, particularly in drainage water and River Nile. 81.4% of presumptive Aeromonas species were identified as A. hydrophila. The effect of seasonal variation showed maximum recovery in summer (61.5%) and spring (28.9%) compared to autumn (5.8%) and winter (3.8%). The time needed to reduce the population by 90% (T90) was 55 h and the calculated decay coefficient was 0.018 h 1. The residual chlorine efficient to inactivate A. hydrophila in drinking water supplies should be maintained at levels not less than 0.7mgL 1. Susceptibility of 72 isolates to 20 different antibiotics revealed recognizable multiple antibiotic resistance phenomenon toward eight (40%) of the tested antibiotics. Sensitivity was mostly directed to norfloxacin, ofloxacin, ceftriaxone, and cefotaxime. The study concluded that, supplementing the traditional indicators index of water quality with Aeromonas levels could be a simple, reliable, and inexpensive valid tool for better microbiological characterization of water.
Rapid quantitative detection of Enteric viruses in River Nile and drainage water, Egypt
(ResearchGate, 2014) Ibrahim Azzam, Mohamed; M. Ezzat, Safaa; A. El-Dougdoug, Khaled; A. Othman, Badawi
Contamination of surface water with enteric viruses is a major public health concern that warrants the need to develop reliable indicators for enteric viruses contamination. This work assesses the bio-diversity of coliphages to use as bio-indicators for viral water pollution. The study elucidates the occurrence of enteric viruses at various locations in Rosetta Branch of the Nile River in addition to five main drains located on its sides which selected for confirmation the eco-diversity of aquatic viral isolates. The evaluation was carried out using real time-quantitative reverse transcriptase - polymerase chain reaction (rt-qRT-PCR). Eight coliphage isolates were detected in both Rosetta Branch and drainage water samples. Transmission Electron microscopy revealed that, the isolated coliphages have an isometric head and long-contractile tail; some particles revealed a short tail with full heads, resembling those belong to the myoviridae and siphoviridae family. Restriction enzymes by EcoRI, HindIII and BamHI showed the presence of double stranded (ds) DNA as well as heterogeneity among these phages. The results showed that EcoRI produced 7, 6, 2, 9, 10, 8, 10, 7 unique fragments and HindIII produced 2, 3, 0, 1, 2, 5, 4, 3 unique fragments while BamHI produced only 4, 0, 1, 1, 0, 4, 2, 1 unique fragments, for the eight phage isolates, respectively. Out of fifteen tested sites, two only (El-Rahawy drain outlet and Sabal drain outlet) were found to be polluted with enteroviruses with rate of 3.6X104 and 3.4X104 gene copies per microliters (GC μl-1), respectively using rt-qRT-PCR.
Water Quality Assessment of River Nile at Rosetta Branch: Impact of Drains Discharge
(Middle-East Journal of Scientific Research, 2012) M. Ezzat, Safaa; M. Mahdy, Hesham; A. Abo-State, Mervat; H. Abd El Shakour, Essam; A. El-Bahnasawy, Mostafa
River Nile is the main source of drinking water in Egypt. Unfortunately, it receives heavy load of industrial, agricultural and domestic wastes from several sources. The aim of the present study is to examine the water quality of about 120 km in River Nile at Rosetta branch and five main drains located on its sides, through several physico-chemical and bacteriological analyses. Results obtained from two seasons trips (summer 2010 and winter 2011) revealed that the water quality along studied area in Rosetta branch is obviously influenced by drains discharge. High concentrations of NH3, total dissolved solids (TDS), electric conductivity (EC), biological oxygen demand (BOD), total alkalinity, turbidity and recognizable depletion in dissolved oxygen (DO) were recorded. Pollution from total and fecal coliforms as well as fecal streptococci exceeding permissible limits pointed out that agricultural and sewage wastes are the key factors in this environmental problem, particularly in winter season. The calculated water quality index (WQI) supported the analytical data and the correlation coefficient matrix between water quality pairs recorded several positive and negative significant relationships. The gradual improvement recognized at the end of the branch especially in summer season is attributed most probably to self-purification and dilution concepts. The study recommended treating wastewater prior to discharge or reuse as well as regular and constant monitoring for River Nile to mitigate health problems outbreaks or any aquatic ecosystem disorders.