TY - JOUR
T1 - Comparison of quantitative PCR and culture-based methods for evaluating dispersal of Bacillus thuringiensis endospores at a bioterrorism hoax crime scene
AU - Crighton, Taryn
AU - Hoile, Rebecca Jane
AU - Coleman, Nicholas V.
PY - 2012/6/10
Y1 - 2012/6/10
N2 - Since the anthrax mail attacks of 2001, law enforcement agencies have processed thousands of suspicious mail incidents globally, many of which are hoax bioterrorism threats. Bio-insecticide preparations containing Bacillus thuringiensis (Bt) spores have been involved in several such threats in Australia, leading to the requirement for rapid and sensitive detection techniques for this organism, a close relative of Bacillus anthracis. Here we describe the development of a quantitative PCR (qPCR) method for the detection of Bt crystal toxin gene cry1, and evaluation of the method's effectiveness during a hoax bioterrorism event in 2009. When combined with moist wipe sampling, the cry1 qPCR was a rapid, reliable, and sensitive diagnostic tool for detecting and quantifying Bt contamination, and mapping endospore dispersal within a mail sorting facility. Results from the cry1 qPCR were validated by viable counts of the same samples on Bacillus-selective agar (PEMBA), which revealed a similar pattern of contamination. Extensive and persistent contamination of the facility was detected, both within the affected mailroom, and extending into office areas up to 30. m distant from the source event, emphasising the need for improved containment procedures for suspicious mail items, both during and post-event. The cry1 qPCR enables detection of both viable and non-viable Bt spores and cells, which is important for historical crime scenes or scenes subjected to decontamination. This work provides a new rapid method to add to the forensics toolbox for crime scenes suspected to be contaminated with biological agents.
AB - Since the anthrax mail attacks of 2001, law enforcement agencies have processed thousands of suspicious mail incidents globally, many of which are hoax bioterrorism threats. Bio-insecticide preparations containing Bacillus thuringiensis (Bt) spores have been involved in several such threats in Australia, leading to the requirement for rapid and sensitive detection techniques for this organism, a close relative of Bacillus anthracis. Here we describe the development of a quantitative PCR (qPCR) method for the detection of Bt crystal toxin gene cry1, and evaluation of the method's effectiveness during a hoax bioterrorism event in 2009. When combined with moist wipe sampling, the cry1 qPCR was a rapid, reliable, and sensitive diagnostic tool for detecting and quantifying Bt contamination, and mapping endospore dispersal within a mail sorting facility. Results from the cry1 qPCR were validated by viable counts of the same samples on Bacillus-selective agar (PEMBA), which revealed a similar pattern of contamination. Extensive and persistent contamination of the facility was detected, both within the affected mailroom, and extending into office areas up to 30. m distant from the source event, emphasising the need for improved containment procedures for suspicious mail items, both during and post-event. The cry1 qPCR enables detection of both viable and non-viable Bt spores and cells, which is important for historical crime scenes or scenes subjected to decontamination. This work provides a new rapid method to add to the forensics toolbox for crime scenes suspected to be contaminated with biological agents.
KW - Anthrax
KW - Bacillus anthracis
KW - Bacillus thuringiensis
KW - Bioterrorism
KW - Endospores
KW - QPCR
UR - http://www.scopus.com/inward/record.url?scp=84861574812&partnerID=8YFLogxK
U2 - 10.1016/j.forsciint.2011.12.003
DO - 10.1016/j.forsciint.2011.12.003
M3 - Article
SN - 0379-0738
VL - 219
SP - 88
EP - 95
JO - Forensic Science International
JF - Forensic Science International
IS - 1-3
ER -