Detecting low concentrations of Shigella sonnei in environmental water samples by PCR.
Outbreaks of Shigella sonnei associated with contaminated water have been reported and methods for the simultaneous detection of Shigellae and enteroinvasive Escherichia coli in water samples have been developed with detection limits of 10(1)-10(2) CFU mL(-1) of water. Because 10(1)-10(2)Shigellae can cause disease, a more sensitive detection method as an addition to the existing methods for detection of Shigella sonnei in water samples is reported here. Initially, 33 Shigella sonnei and 72 non-Shigella sonnei isolates were tested and one primer pair was found capable of specifically amplifying a 369-bp insertion sequence 1 (IS1) fragment from all 33 Shigella sonnei isolates and one Shigella dysenteriae ATCC isolate by PCR. The detection method was developed, which included filtration of 50 mL of water through a membrane and application of PCR to the membrane using this primer pair. Environmental water samples with total bacterial numbers of 384-2.84 x 10(7) CFU L(-1) were collected and seeded with 13 Shigella sonnei and the Shigella dysenteriae ATCC isolates. Detection limits were determined as 1.7-24.7 and 270-8000 CFU per 50 mL of water, respectively, using this detection method.
Hsu
Wen-Bin
WB
Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan, Republic of China.
Wang
Jiann-Haur
JH
Chen
Pei-Chun
PC
Lu
Yu-Shiou
YS
Chen
Jiann-Hwa
JH
D001483:Base Sequence; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D012760:Shigella / Q000235:genetics; D012762:Shigella dysenteriae / Q000235:genetics; D012764:Shigella sonnei / Q000235:genetics*; D014871:Water Microbiology
D017931:DNA Primers; D004269:DNA, Bacterial