Application of quantitative real-time PCR compared to filtration methods for the enumeration of Escherichia coli in surface waters within Vietnam.
Surface water samples in Vietnam were collected from the Saigon River, rural and suburban canals, and urban runoff canals in Ho Chi Minh City, Vietnam, and were processed to enumerate Escherichia coli. Quantification was done through membrane filtration and quantitative real-time polymerase chain reaction (PCR). Mean log colony-forming unit (CFU)/100 ml E. coli counts in the dry season for river/suburban canals and urban canals were log 2.8 and 3.7, respectively, using a membrane filtration method, while using Taqman quantitative real-time PCR they were log 2.4 and 2.8 for river/suburban canals and urban canals, respectively. For the wet season, data determined by the membrane filtration method in river/suburban canals and urban canals samples had mean counts of log 3.7 and 4.1, respectively. While mean log CFU/100 ml counts in the wet season using quantitative PCR were log 3 and 2, respectively. Additionally, the urban canal samples were significantly lower than those determined by conventional culture methods for the wet season. These results show that while quantitative real-time PCR can be used to determine levels of fecal indicator bacteria in surface waters, there are some limitations to its application and it may be impacted by sources of runoff based on surveyed samples.
Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines.
Pierangeli G
PG
Vital
Ministry of Natural Resources and Environment, Ho Chi Minh City University for Natural Resources and Environment, 236B Le Van Sy Street, Ward 1, Tan Binh District, Ho Chi Minh City, Vietnam.
Nguyen Thi
NT
Van Ha
Ministry of Natural Resources and Environment, Ho Chi Minh City University for Natural Resources and Environment, 236B Le Van Sy Street, Ward 1, Tan Binh District, Ho Chi Minh City, Vietnam.
Le Thi Hong
LT
Tuyet
International Environmental Research Center, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Bukgu, Gwangju 61005, Republic of Korea E-mail: kwidmer@gist.ac.kr.
Kenneth W
KW
Widmer
D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D005374:Filtration / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D045483:Rivers / Q000382:microbiology*; D014744:Vietnam