[Detection of enteric pathogenic bacteria from surface waters by quantitative polymerase chain reaction (QPCR)].
A rapid quantitative polymerase chain reaction (QPCR) analysis method with universal primers was developed to detect cell densities of the enteric pathogenic bacteria from 5 surface water of Xi'an City for 4 months continuously. And the detection results by QPCR method were compared with counts of coliforms colony-forming units (CFU) determined by membrane filter (MF) analysis. The results showed that QPCR method had an estimated 94% confidence, and detection limit was 2.7 Escherichia coli cells per sample in undiluted DNA extracts. For five surface waters (N = 60), the geometric mean of pathogenic bacteria concentration determined by QPCR was 2.2-5 times of corresponding coliform CFU determined by MF analysis. Using QPCR analysis, these geometric means of pathogenic bacteria concentration ranged from 25 CCE/100 mL to 67 000 CCE/100 mL. Using MF culture analysis, coliforms ranged from 3 CFU/100 mL to 45 000 CFU/100 mL. Regression analysis showed that there was a significant positive correlation between pathogenic bacteria determined by QPCR method and coliforms determined by MF method, the correlation coefficient (r) was 0.983.
Liu
Yong-Jun
YJ
Key Laboratory of Northwest Water Resource, Ecology and Environment, Ministry of Education, Xi' an University of Architecture and Technology, Xi'an 710055, China. liuyongjun@xauat.edu.cn
Zhang
Chong-Miao
CM
Wang
Xiao-Chang
XC
Lü
Ying-Jun
YJ
Zuo
Li-Li
LL
D004755:Enterobacteriaceae / Q000235:genetics / Q000302:isolation & purification*; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012485:Salmonella typhi / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D012762:Shigella dysenteriae / Q000235:genetics / Q000302:isolation & purification; D014871:Water Microbiology; D014876:Water Pollution / Q000032:analysis*
D012336:RNA, Ribosomal, 16S