| Abstrakt: |
This work carried out to analyze the microbiology and physicochemical parameters of water in some Nile tilapia fish farms in Kafrelsheikh Governorate. Total bacterial and total coliform count were carried out, as well as the presence of E.faecalis, E.coli, and E.coli O157 in both fish and farms water. The level of total bacterial count in water varied between 4.3x104 and 1.3x106 CFU/ml. The most probable number (MPN) of total coliform ranged between <3 and >1100/ml between different sampling sites. E.faecalis verified in 28% and 38% of fish, and, water samples respectively E.coli isolated in 18% and 34% from fish and water samples. E.coli O157 verified in 2% of fish samples and does not present in water samples. Sero-grouping of E.coli isolates revealed that E.coli belongs to five sero-groups (O6, O27, O125, O126, and O157). Results of microbiology were confirmed by results of physicochemical parameters of the water samples where values of pH, conductivity, salinity, ammonia, nitrite, sulphate, chlorine, chloride, total solids, total suspended solids, and total dissolved solids in farms number two, six, and ten when compared with other farms were significantly (P<0.05) increased in the same farms, which contain high coliform count. Multiple antibiotic resistance was recorded in 18/28 E.faecalis isolates (64.3%) and in all E.coli isolates 20/20 (100%). Eight randomly selected isolates of E.faecalis were confirmed by polymerase chain reaction (PCR) using specific 16Sr RNA showed that seven from the eight examined isolates were positive with a product band (310 bp). In addition, the two isolates of E.coli O157 were harboring rfbE gene with a product band (134 bp). It could be concluded that, microbial and chemical evaluation of water in fish farms is the best witness for levels of water pollution and risk of usage of agriculture wastewater. Besides the development of antimicrobial resistance by different bacteria calling for concern to public health hazard. [ABSTRACT FROM AUTHOR] |
