Publication: Light scattering sensor for direct identification of colonies of Escherichia coli serogroups O26, O45, O103, O111, O121, O145 and O157.
Accepted Date
2014-07-18
Issued Date
2014-08-19
Copyright Date
2014
Resource Type
Language
eng
ISSN
1932-6203 (electronic)
Rights
Mahidol University
Rights Holder(s)
PLoS One
Bibliographic Citation
Tang Y, Kim H, Singh AK, Aroonnual A, Bae E, Rajwa B. et al. Light scattering sensor for direct identification of colonies of Escherichia coli serogroups O26, O45, O103, O111, O121, O145 and O157. PLoS One. 2014 Aug 19;9(8):e105272.
Suggested Citation
Tang, Yanjie, Kim, Huisung, Singh, Atul K., Amornrat Aroonnual, อมรรัตน์ อรุณนวล, Bae, Euiwon, Rajwa, Bartek, Fratamico, Pina M., Bhunia, Arun K. Light scattering sensor for direct identification of colonies of Escherichia coli serogroups O26, O45, O103, O111, O121, O145 and O157.. Tang Y, Kim H, Singh AK, Aroonnual A, Bae E, Rajwa B. et al. Light scattering sensor for direct identification of colonies of Escherichia coli serogroups O26, O45, O103, O111, O121, O145 and O157. PLoS One. 2014 Aug 19;9(8):e105272.. doi:10.1371/journal.pone.0105272. Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/766
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Title
Light scattering sensor for direct identification of colonies of Escherichia coli serogroups O26, O45, O103, O111, O121, O145 and O157.
Corresponding Author(s)
Abstract
BACKGROUND: Shiga-toxin producing Escherichia coli (STEC) have emerged as
important foodborne pathogens, among which seven serogroups (O26, O45, O103,
O111, O121, O145, O157) are most frequently implicated in human infection. The
aim was to determine if a light scattering sensor can be used to rapidly identify
the colonies of STEC serogroups on selective agar plates.
METHODOLOGY/PRINCIPAL FINDINGS: Initially, a total of 37 STEC strains
representing seven serovars were grown on four different selective agar media,
including sorbitol MacConkey (SMAC), Rainbow Agar O157, BBL CHROMagarO157, and
R&F E. coli O157:H7, as well as nonselective Brain Heart Infusion agar. The
colonies were scanned by an automated light scattering sensor, known as BARDOT
(BActerial Rapid Detection using Optical scattering Technology), to acquire
scatter patterns of STEC serogroups, and the scatter patterns were analyzed using
an image classifier. Among all of the selective media tested, both SMAC and
Rainbow provided the best differentiation results allowing multi-class
classification of all serovars with an average accuracy of more than 90% after
10-12 h of growth, even though the colony appearance was indistinguishable at
that early stage of growth. SMAC was chosen for exhaustive scatter image library
development, and 36 additional strains of O157:H7 and 11 non-O157 serovars were
examined, with each serogroup producing unique differential scatter patterns.
Colony scatter images were also tested with samples derived from pure and mixed
cultures, as well as experimentally inoculated food samples. BARDOT accurately
detected O157 and O26 serovars from a mixed culture and also from inoculated
lettuce and ground beef (10-h broth enrichment +12-h on-plate incubation) in the
presence of natural background microbiota in less than 24 h.
CONCLUSIONS: BARDOT could potentially be used as a screening tool during
isolation of the most important STEC serovars on selective agar plates from food
samples in less than 24 h.