Light‐scattering sensor for real‐time identification of V ibrio parahaemolyticus , V ibrio vulnificus and V ibrio cholerae colonies on solid agar plate

• Published in: Microbial biotechnology Vol. 5; no. 5; pp. 607 - 620
• Main Authors: Huff, Karleigh, Aroonnual, Amornrat, Littlejohn, Amy E. Fleishman, Rajwa, Bartek, Bae, Euiwon, Banada, Padmapriya P., Patsekin, Valery, Hirleman, E. Daniel, Robinson, J. Paul, Richards, Gary P., Bhunia, Arun K.
• Format: Journal Article
• Language: English
• Published: 01-09-2012
• ISSN: 1751-7915; 1751-7915
• DOI: 10.1111/j.1751-7915.2012.00349.x

The three most common pathogenic species of
V
ibrio
,
V
ibrio cholerae
,
V
ibrio parahaemolyticus
and
V
ibrio vulnificus
, are of major concerns due to increased incidence of water‐ and seafood‐related outbreaks and illness worldwide. Current methods are lengthy and require biochemical and molecular confirmation. A novel label‐free forward light‐scattering sensor was developed to detect and identify colonies of these three pathogens in real time in the presence of other vibrios in food or water samples.
V
ibrio
colonies grown on agar plates were illuminated by a 635 nm laser beam and scatter‐image signatures were acquired using a
CCD
(charge‐coupled device) camera in an automated
BARDOT
(
BA
cterial
R
apid
D
etection using
O
ptical light‐scattering
T
echnology) system. Although a limited number of
V
ibrio
species was tested, each produced a unique light‐scattering signature that is consistent from colony to colony. Subsequently a pattern recognition system analysing the collected light‐scatter information provided classification in 1−2 min with an accuracy of 99%. The light‐scattering signatures were unaffected by subjecting the bacteria to physiological stressors: osmotic imbalance, acid, heat and recovery from a viable but non‐culturable state. Furthermore, employing a standard sample enrichment in alkaline peptone water for 6 h followed by plating on selective thiosulphate citrate bile salts sucrose agar at 30°
C
for ∼ 12 h, the light‐scattering sensor successfully detected
V
. cholerae
,
V
. parahaemolyticus
and
V
. vulnificus
present in oyster or water samples in 18 h even in the presence of other vibrios or other bacteria, indicating the suitability of the sensor as a powerful screening tool for pathogens on agar plates.