Optical scatter patterns facilitate rapid differentiation of Enterobacteriaceae on CHROMagar™ Orientation medium.
Enterobacteriaceae family comprised pathogens and commensals and has a significant impact on food safety and public health. Enterobacteriaceae is often enumerated and presumptively identified on chromogenic media, such as CHROMagar(TM) Orientation medium based on colony profile; however, classification is highly arbitrary, and some could not be differentiated due to similar chromogen production. Here, we investigated the ability of the laser optical sensor, BARDOT (bacterial rapid detection using optical scattering technology) for rapid screening and differentiation of colonies of the major bacterial genera from Enterobacteriaceae on CHROMagar(TM) Orientation. A total of 36 strains representing 12 genera and 15 species were used to generate colony scatter image library that comprised 1683 scatter images. This library was used to differentiate mixed cultures of Enterobacteriaceae family - Klebsiella pneumoniae, Enterobacter spp., Citrobacter freundii and Serratia marcescens (KECS group); Proteus mirabilis, Morganella morganii and Providencia rettgeri (PMP group); and non-Enterobacteriaceae family: Pseudomonas aeruginosa, Acinetobacter spp. and Staphylococcus aureus (PAS group) - and data show high accuracy (83-100%) for intra-group classification of colonies in 10-22 h or even before visible production of chromogens. BARDOT successfully differentiated the major genera, including the ones that do not produce visually distinguishable chromogens on CHROMagar(TM) Orientation, providing a label-free, real-time on-plate colony screening tool for Enterobacteriaceae.
Department of Food Science, Molecular Food Microbiology Laboratory, Purdue University, West Lafayette, IN, 47907, USA.
Atul K
http://orcid.org/0000-0001-7343-3577
AK
Singh
Department of Food Science, Molecular Food Microbiology Laboratory, Purdue University, West Lafayette, IN, 47907, USA.|Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, 47907, USA.
Arun K
AK
Bhunia
D015373:Bacterial Typing Techniques / Q000295:instrumentation / Q000379:methods*; D003470:Culture Media / Q000737:chemistry*; D004755:Enterobacteriaceae / Q000737:chemistry / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D055095:Optics and Photonics / Q000379:methods*
D003470:Culture Media