Detection of E. coli O157: H7 by immunological and real-time PCR methods in the water treatment plant

Document Type : Original Article

Authors
Peymaneh Atabakhsh 1
Mohammad Mehdi Amin 2
Hossein Mortazavi 3
Parinaz Poursafa 2
Majid Yaran 4
Abbas Akhavan Sepahi 5
Mohammad Jalali 6
Ashraf Al sadat Noohi 5
1 Isfahan Water and Wastewater Company, Isfahan; Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Environment Research Center, Isfahan University of Medical Sciences (IUMS), Isfahan, Iran
3 Isfahan Water and Wastewater Company, Isfahan, Iran
4 Infectious Diseases and Tropical Medicine Research Center, IUMS, Isfahan, Iran
5 Science and Research Branch, Islamic Azad University, Tehran, Iran
6 Food Security Research Center, IUMS, Isfahan, Iran
Abstract
Aims: There is limited data on the occurrence of E. Coli O157: H7 in water. Therefore, this study aims to detect E. Coli O157: H7 in the Water Treatment Plant (WTP). Materials and Methods: This cross-sectional study was conducted in Isfahan WTP, central of Iran. Immunological methods were implemented with anti-serum kits and the molecular method of reverse transcription-polymerase chain reaction (RT-PCR) was used to detect E. Coli O157: H7 in eight locations of the WTP; the sludge of the sedimentation basin and filter backwash water were also monitored. The survival of E. Coli O157: H7 in the sludge samples of the sedimentation basin was indicated by the formation of agglutination particles using the immunological method, and through indicator probes using the RT-PCR method. Results: E. Coli O157: H7 was not detected in the water samples from the WTP units. The removal percent of total coliforms (TC), fecal coliforms (FC), and Heterotrophic Plate Count (HPC), respectively, were as follows: 59.5, 49, and 54.8% in the sedimentation basin; 66, 45.8, and 57% in the ozonation system; 98.8, 98, and 78.8% in the filtration system; and 96, 100, 91% in the disinfection system. Conclusions: This study revealed the existence of the pathogenic coliform of E. Coli O157: H7 in the sludge of the sedimentation basin. The absence of E. Coli O157: H7 in the finished water indicated that the WTP units were able to eliminate these pathogenic bacteria before reaching the final units of the plant, including the filtration and disinfection systems.

Keywords

International Journal of Environmental Health Engineering (IJEHE)
Volume 1, March
Winter 2012
Pages 30-35

  • Receive Date 06 February 2023