Detection of viable Giardia cysts by amplification of heat shock-induced mRNA.
Primers obtained from gene sequences coding for heat shock proteins (HSP) were used to specifically detect enteric protozoans of the genus Giardia. The HSP primers amplified Giardia DNA or the corresponding RNA sequences obtained from lysed cysts and gave a 163-bp product. Since the presence of the product did not indicate whether the cysts were viable, these amplifications are a presence/absence test only. In contrast, amplification of heat shock-induced mRNA utilizing the same HSP primers was indicative of viable Giardia cysts. The limit of sensitivity of the presence/absence test was 1 cyst, whereas for the viability test it was 10 cysts. Thus, viable Giardia cysts can be rapidly and specifically detected with great sensitivity through the use of PCR amplifications.
Abbaszadegan
M
M
Quality Control & Research Laboratory, American Water Works Service Company, Inc., Belleville, Illinois 62220, USA.
Huber
M S
MS
Gerba
C P
CP
Pepper
I L
IL
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D005872:Giardia / Q000235:genetics* / Q000302:isolation & purification*; D006360:Heat-Shock Proteins / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods / Q000706:statistics & numerical data; D015800:Protozoan Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics*; D016053:RNA, Protozoan / Q000235:genetics*; D012680:Sensitivity and Specificity
D017931:DNA Primers; D006360:Heat-Shock Proteins; D015800:Protozoan Proteins; D012333:RNA, Messenger; D016053:RNA, Protozoan